Biobased Polymers: Properties and Applications in Packaging 0128184043, 9780128184042

Biobased Polymers: Properties and Applications in Packaging looks at how biopolymers may be used in packaging as a poten

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Biobased Polymers: Properties and Applications in Packaging
 0128184043, 9780128184042

Table of contents :
Content: 1. Introduction2. Description of biobased polymers3. Properties of biobased packaging material4. Packaging types5. Biobased polymers in packaging6. Recent Trends in Packaging of Food Products7. Environmental impact of biobased polymers8. Legislation for food contact materials9. Market for biobased packaging material10. Emerging sources of biopolymers11. Emerging technology - Nanotechnology12. Future prospects

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BIOBASED POLYMERS Properties and Applications in Packaging

PRATIMA BAJPAI

Elsevier Radarweg 29, PO Box 211, 1000 AE Amsterdam, Netherlands The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States Copyright © 2019 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-0-12-818404-2 For information on all Elsevier publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Susan Dennis Acquisition Editor: Kostas Marinakis Editorial Project Manager: Redding Morse Production Project Manager: Prem Kumar Kaliamoorthi Cover Designer: Greg Harris Typeset by TNQ Technologies

“Dedicated to my beloved parents & family” For their love, endless support, encouragement & sacrifices.

List of figures Figure 3.1 Figure 3.2 Figure 3.3 Figure Figure Figure Figure Figure Figure

3.4 3.5 3.6 3.7 3.8 3.9

Figure 3.10 Figure Figure Figure Figure: Figure

3.11 3.12 3.13 3.14 3.15

Figure 3.16 Figure 3.17 Figure 3.18 Figure 3.19 Figure 4.1 Figure 4.2 Figure 6.1

Figure 6.2

Structure of amylose. Structure of amylopectin. Molecular structure of cellulose representing the cellobiose unit as a repeating unit. Structure of chitin and chitosan. Structure of pullulan. Structure of alginate. Structure of carrageenan. Structure of xanthan gum. General structure of class 1 dextrans consisting of a linear backbone of a(1/6)-linked D-glucopyranosyl repeating units. (A) A repeating segment of pectin molecule and functional groups: (B) carboxyl; (C) ester; (D) amide in pectin chain. Structure of b-glucan. Structure of gellan. Gelatin. Chemical structure of polylactic acid (PLA). Synthesis of high-molecular-weight PLA from L- and D-lactic acids. Polybutylene succinate. PBS and its production route. Structure of PHAs with respect to classification. PE macromolecule carbon chain. Rigid packaging. Flexible packaging. Examples of time-temperature indicators: (A) Fresh-Check by Temptime Corporation (USA) (B) CoolVu by Freshpoint (Switzerland (C) Checkpoint by Vitsab International AB (Sweden) (D) OnVu by Freshpoint (Switzerland) (E) Tempix by Tempix AB (Sweden) and (F) Timestrip by Timestrip (UK). Example of: (A) a 1-D barcode; B) a PDF 417 2-D barcode; and (C) a QR 2-D barcode.

27 28 34 40 43 45 48 51

53 56 57 58 61 73 74 79 80 83 85 114 120

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List of figures

Figure 7.1

Figure 7.2

Figure 7.3

Prevalence of environmental impact indicators (damage or resource indicators) in 72 published life cycle analysis (LCA) studies on biobased (nonenergy) products. Average product-specific environmental impacts of biobased materials in comparison to conventional materials (Dij). Uncertainty intervals represent the standard deviation of data. Numbers in parentheses indicate the sample size for the functional units of per metric ton and per hectare and year, respectively. Average nonrenewable primary energy use and greenhouse gas (GHG) emissions of biobased chemicals in comparison to conventional chemicals (Dij). Uncertainty intervals represent the standard deviation of data. Numbers in parentheses indicate the sample size for the biobased and conventional chemicals, respectively.

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List of tables Table 1.1 Table 1.2 Table 2.1 Table 2.2 Table 2.3 Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 3.5 Table 3.6 Table 3.7 Table 3.8 Table 3.9 Table 3.10 Table 3.11 Table 3.12 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 4.6 Table 4.7 Table 4.8 Table 6.1 Table 6.2 Table 6.3 Table 6.4 Table 6.5 Table 6.6 Table 6.7

Advantages of natural biopolymer films. 5 Classification of biopolymers depending on the general chemical composition. 8 Bioplastics (European Bioplastics Association). 14 Criteria used for sorting biopolymers. 14 Manufacturers of biopolymers. 15 Biobased polymers produced by various processes. 26 Applications of starch products. 30 Properties and applications of modified starches. 30 Suppliers of starch-based products. 32 Global suppliers of cellulosic products. 36 Manufacturers producing cellulose-based polymer films for packaging. 37 Industrially important cellulose derivatives. 37 Advantages of PLA over traditional petroleum-based polymers. 73 Glass transition and melting temperature of PLA with various ratios of L-monomer composition. 75 Suppliers of PLA. 78 Suppliers of PBS. 81 Global suppliers of various types of PHAs. 89 Rigid packaging. 113 Global rigid plastic packaging consumption. 117 Key players for the rigid packaging market. 117 Types of flexible packaging. 119 Main flexible packaging materials. 120 Types of flexible plastics. 120 Advantages of flexible packaging over rigid containers. 124 Key manufacturers of flexible packaging. 126 The importance of packaging. 140 Role of packaging. 140 Active and intelligent packaging systems. 142 A few examples of active packaging systems. 143 Attributes of commercial oxygen scavengers. 144 Advantages of antimicrobial edible coatings and films. 148 Commercial active packaging systems. 153

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List of tables

Table 6.8 Table 6.9 Table 6.10 Table 6.11 Table 6.12 Table 7.1 Table 8.1 Table 8.2 Table 9.1 Table 11.1

TTIs’ market applications. Commercial applications of freshness indicators. Gas indicators. Thermochromic inks are produced by several companies. Commercial intelligent packaging systems. Energy and greenhouse gas savings. Types of food contact materials. European legislation and other resources. Global market share for biopolymers used in packaging by value, 2010 (%). Diverse applications of nanotechnology.

155 157 157 161 161 174 185 188 192 204

Preface

Development of biobased material is one important factor for sustainable growth of the packaging industry. Recent trends in the consumer market have moved toward greener packaging. Driven by biodegradability and biorenewability trends, the demand for biobased materials in packaging is expected to grow to about 9.45 million tons by 2023. The issue of sustainability has been high for the last several years, encouraging academia as well as industry to develop sustainable alternatives for preserving resources for future generations. The successful use of renewable biological materials for the production of packaging materials will satisfy a number of the major objectives. To a large extent, packaging materials are based on nonrenewable materials. The only widely used renewable packaging materials are paper and board, which are based on cellulose, which is the most abundant renewable polymer. However, significant efforts are being made to identify alternative nonfood uses of agricultural crops and the production of packaging materials, based on polymers from agricultural sources. Such alternative biobased packaging materials have attracted considerable research and development interest for a significant length of time, and in recent years these materials have reached the market. Eco-concerns played a major role in encouraging the development of biopolymers in packaging applications. This occurred directly via consumer demand for eco-friendly products as well as indirectly via the political and ensuing regulatory environment. Sources of biopolymers that are expected to become increasingly significant include those that do not compete with food production for resources, such as algae, and materials suitable for packaging applications based on algae are projected for launch soon. Furthermore, technological advances, such as those based on nanotechnology, are forecast to continue improving biopolymer properties and increasing the number of potential applications for such materials in packaging. This book looks at how biopolymers may be used in packaging as a potential green solution. It addresses biobased feedstocks, production processes, packaging types, recent trends in packaging, environmental impacts of biobased polymers, and legislative demands for food contact packaging materials. It covers opportunities for biopolymers in key end use sectors and penetration of biopolymer-based concepts in the packaging market, as well as barriers to widespread commercialization.

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Acknowledgments

Some excerpts taken from Gange A (2010). Biopolymers in Packaging Applications IntertechPira, USA, with kind permission. Some excerpts taken from Bajpai P (2016). Pulp and Paper Industry, First Edition: Nanotechnology in Forest Industry, Elsevier, USA with kind permission. Some excerpts taken from Biji KB, Ravishankar CN, Mohan CO, and Srinivasa Gopa l TK (2015). Smart packaging systems for food applications: a review. J Food Sci Technol., 52(10): 6125e6135 with kind permission. Some excerpts taken from Weiss M, Haufe J, Carus M, Brand~ao M, Bringezu S, Hermann B, and Patel MK (2012). A review of the environmental impacts of biobased materials. Journal of Industrial Ecology, 16(S1): S169e81 with kind permission. Some excerpts taken from Day BPF and Potter L (2011). Active Packaging in Food and Beverage Packaging Technology, Second Edition. Edited by Richard Coles and Mark Kirwan. Blackwell Publishing Ltd. with kind permission. Some excerpts taken from Bajpai P (2016). Pretreatment of Lignocellulosic Biomass for Biofuel Production, SpringerBriefs in Green Chemistry for Sustainability. Springer Nature America, Inc. with kind permission. Some excerpts taken from Bajpai P (2018). Third Generation Biofuels. Springer Briefs in Energy. Springer Nature Singapore Pte Ltd. with kind permission. Some excerpts taken from Babu, RP, O’Connor K, and Seeram, R (2013). Current progress on bio-based polymers and their future trends. Prog. Biomater, 2(8): 1e16 with kind permission. Khwaldia, K (2010). Water vapor barrier and mechanical properties of paperesodium caseinate and paperesodium caseinateeparaffin wax films. Journal of Food Biochemistry, 34: 998e1013 with kind permission.

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CHAPTER 1

Background and introduction Contents References Relevant websites

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“The packaging industry currently, depends strongly on the petroleum-based plastics which cause concerns to future in relevance with both environment and the economy” (Shahzad Tariq, 2013). The shortage of raw materials also creates a threat to the availability, cost of raw materials and their biodegradability (Gustafsson et al., 2011). There are several reasons to search out alternatives to petroleum-based plastics: depletion of fossil fuels, a wildly unsteady oil price, the need to reduce carbon emissions, an accumulation of plastic waste, and the need for packaging materials having new characteristics. In response, researchers have developed a whole new generation of plant or plant-waste-based packaging materials, some having characteristics such as breathability or antimicrobial properties. There are already countless applications for them. The European Union (EU) market for packaging has a value of about 127 billion US dollars and has about 40 percent of the global packaging market (Shahzad Tariq. 2013). The European packaging materials can be broken down as contribution from glass with 8%, metal 14%, paper 42%, and plastic 36% (Global Packaging Alliance, 2013). Furthermore, petroleum-based products lack biodegradability. This can cause substantial waste disposal problems in certain areas (de Vlieger, 2003; Robertson, 2008; Franz and Welle, 2003). Packaging is becoming a very important part of our daily life. The utilization of packaging materials is continuously increasing with time. It is expected that in the future the market will grow globally. Packaging products produced from renewable substrates currently represent only about 2% of the market: traditional fiber-based packaging is not included. “Substantial attention is now being given to the concept of sustainable development. The commonly accepted definition of sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (World Commission on Environment and Development’s report “Our Common Future,” 1987) (www.sustainabledevelopment2015.org/ AdvocacyToolkit/.../92-our-common-future). For a transition to a higher level of sustainability development, it is very important to make a number of technological and social changes, and one of these is to develop alternative resources of raw materials.

Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00001-1

© 2019 Elsevier Inc. All rights reserved.

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Sustainable development is becoming the core commitment to create shared value by increasing world access to the best quality available in food and beverages while focusing on staying being eco-friendly. One project is led by a Swedish firm, Innventia, a partly government industrial research company, with the aim to explore the niche in biobased/ ecofriendly packaging materials. Food packaging is a large and complex market, providing protection, tamper resistance, and special physical, chemical, or biological requirements. Most, if not all of this, can be handled by biobased materials. Focusing alone on the sustainable development of the packaging material is not enough and is shortsighted. That is why the industry has increased the communication efforts to realize the pros and cons on the whole chain, i.e., raw materials to processing to wholesale and retail to use and finally to disposal. For sustainable growth of the packaging industry, it is very important to develop high-performance sustainable raw materials. The sustainable packaging sector is growing at a faster rate as compared to the overall packaging industry. Studies conducted by several research institutions in Germany and Sweden show that from a carbon footprint perspective, packaging materials from forest resources can deliver several benefits in comparison to conventional plastics or glass packages. Paperboard due to its renewability is better than glass or plastic containers for packaging of liquids (Wellenreuther et al., 2010; Jelse et al., 2011). Furthermore, the weight of biobased packaging is lower. This property is favorable from a transportation point of view. The final products are usually reused (Hohenthal and Veuro, 2011). Consumers usually like fiber-based packaging as it is eco-friendly. Biopolymers used as dispersion coating on paper or paperboard for use in packaging and bioplastics with the same intended use offer enough barrier properties for fats, but generally have only reasonable water vapor barrier properties. Poor mechanical properties, inadequate heat resistance, and high sensitivity to moisture as compared to plastics obtained from petroleum are other weak points. Furthermore, to become competitive it is essential that biopackaging solutions should be economically feasible and can be included in the industrial processes. It is important to remember that the role of packaging now revolves about around three conceptsdenvironmental, economic, and socialdcovering the aspects of sustainability. The recent trends in EU packaging markets show an interest of moving toward what is called “green” packaging, i.e., using recyclable and recycled materials, reduced material usage, and polymers extracted from biomass. The accomplishment has been driven by EU directives for the evolution of eco-friendly packaging solutions in the EU (Parker, 2008). Some of the research groups that have pursued packaging from renewable materials are SustainPack, SustainComp, Food Biopack project, SUNPAP, FlexPakRenew, RenewFunccBarr, and VTT ( Johansson et al., 2012; Shahzad Tariq, 2013).

Background and introduction

The Food Biopack project provided information on the production and use of biopackaging materials for the food industry, covering the entire perspective from properties of biomaterials to food packaging considerations, life cycle analysis, ecological impacts, as well as market issues (Weber, 2000a,b). SustainPack has dealt with improvements in a range of packaging functionalities. Selfhealing coatings were developed for maintaining the barrier properties of packages when subjected to external stress (Andersson et al., 2009). Other problems that were addressed included printed electronics for communication, nanosized thin top layers for improved barrier performance, and cellulose fibers for reinforcement (Robertsson, 2008; AmbergSchwab and Kleebauer, 2007; Aucejo, 2005). FlexPakRenew developed environmentally friendly paper packaging from sustainable raw materials. The objective was to substitute barrier films obtained from petroleum and to develop a biodegradable multilayer packaging structure in which the separate layers would contribute to the performance of the packaging. “Study was conducted for improving the flexible base paper by wet-end processing, to reinforced bio-based coatings for barriers against water vapor, oxygen, and grease to the application of thin nanocoatings to further improve the barrier properties, and to the inclusion of sustainable materials with antimicrobial functionalities for extended shelf life of food products. Life cycle analyses were made for evaluating the sustainability of the final product with detailed study of every component” ( Johansson et al., 2012). RenewFuncBarr project from Sweden aimed at developing cost-effective, sustainable production of sustainable materials for use in food packaging. Starch, proteins, and waste products were used. Conventional methods like coating with water-based dispersions and extrusion were used along with plasma deposition and electrospinning methods for improving barrier functionality. In the SustainComp project, sustainable composite materials are addressed. The SUNPAP project focuses on scaling up production of nanoparticles for developing sustainable packaging products. The Agrobar project concentrates on products obtained from agricultural raw materials for utilization in barrier coatings. The Enzycoat and Enzycoat II projects are developing active packaging using oxygen scavengers included in barrier coatings consisting of biomaterials. Packaging has always been under discussion, criticism and apparently a “quiet revolution.” There is always a debate to redesign and discover new packaging materials, but the process on the whole is very complex. It involves the alignment of four key players: packaging manufacturers, fast-moving consuming goods companies, retailers, and government and trade bodies. The ultimate potential in this sector is not realized since the uncertainty faced by investors, due to legitimacy and legislation issues, is high in these turbulent and volatile economic situations (Staffan Jacobson, 2008).

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In spite of these issues, biobased packaging is showing promise in terms of price and technical feasibility. Price can effectively improve if economies of scale are considered. This would make biobased packaging competent. This type of packaging appears to be the appropriate solution for plastic waste collected in the seas, which is having dangerous effects on sea life and affecting human health. Earlier, the manufacturing practices focused only on improving the methods that could help in obtaining more quantities by optimization of the process parameters. But now, the world is changing. Critical issues such as sustainability have activated the need for manufacturing practices that are not only economically advantageous but also advantageous in the context of environment and society. In the world of plastics, biobased packaging materials can solve the issues mentioned above. Packaging materials protect and produce appropriate physicochemical conditions for products important for achieving a longer shelf life. The packaging system, based on a proper selection of the packaging material supplied with proper barrier and mechanical properties, prevents product spoilage and maintains the packaged item’s quality during storage. It is important that the packaging material should biodegrade in a reasonable time period without creating any environmental problems. In this regard, biopackaging materials have a few advantageous properties for improving the quality of food and increasing the shelf life through reducing the growth of microorganisms in the product. They are able to serve as barriers to gases, moisture, water vapor, and solutes and can serve as carriers of some active substances (Rhim and Ng, 2007). Biopolymer films also can function similarly and augment other types of packaging by increasing the shelf life of foods and improving the quality (Wong et al., 1994). Moreover, these films can incorporate different additives, for instance, antimicrobials, antioxidants, antifungal products, colors, and other nutrients (Han, 2000; Baldwin, 1994; Wong et al., 1994). In comparison to synthetic polymers, natural biopolymers show many advantages in that they are renewable, edible, and can be biodegraded. But their mechanical properties and barrier properties are relatively poor. This causes a main constraint for their use on a commercial scale. Polysaccharide and protein films usually show good oxygen barrier properties at low to intermediate relative humidity and possess good mechanical properties; but their water vapor barrier properties are not good because they are hydrophilic (Gontard et al., 1994; Avena-Bustillos and Krochta, 1993; Kester and Fennema, 1986). Research and development (R&D) is being conducted on modification of properties of natural biopolymer films for improving their mechanical and barrier properties (Rhim and Ng, 2007; Rhim, 2004; Rhim and Weller, 2000; Micard et al., 2000; Rhim et al., 1998, 1999; 2000; Gennadios et al., 1993, 1998; Ghorpade et al., 1995; Park et al., 1993). Polymer nanocomposite materials, contain constituents having dimensions on the nanometer scale. These topics are intensely researched in the field of material and polymer science, electronics, and biomedical science (Sinha Ray and Okamoto, 2003a,b; Vaia and Giannelis, 1997; Giannelis, 1996). A polymer nanocomposite is the hybrid material. It contains a polymer matrix

Background and introduction

strengthened with a fiber, platelet, or particle having one dimension on the nanometer scale (Pandey et al., 2005). Because of the nanometer-size particles dispersed in the polymer matrix, these nanocomposites show significantly improved properties when compared with the pure polymer or conventional composites. Improvements may include higher moduli, strength and heat resistance, and reduced gas permeability and flammability with very low filler loading, typically 5 wt% or lower (Alexandre and Dubois, 2000). Hence, natural biopolymers have been filled with layered silicates for enhancing their properties while maintaining their biodegradability. The impressive increase of the material properties of the nanocomposite films in comparison to the pure polymers can be obtained without the requirement for cost-increasing processing. Furthermore, biodegradability is still retained. Only inorganic, natural minerals remain after the final degradation Rhim and Ng, 2007; Sinha Ray et al., 2003a,b,c; Yu et al., 2003; Schmidt et al., 2002

Table 1.1 shows the benefits of natural biopolymer films in comparison to conventional plastic materials. Biobased packaging materials derived from natural sources show great potential for improving the quality of food, safety, and stability as a novel packaging and processing technology. The distinctive benefits of the natural biobased packaging may develop new products, like carriers for functionally active substances, individual packaging of particulate foods, and nutritional supplements. The food industry is actively focusing on using biobased packaging materials (U.S. Congress, 1993). Biobased materials possess specific characteristics, such as more suitable barrier properties, which make them a better choice in comparison to traditional

Table 1.1 Advantages of natural biopolymer films.

Low cost and abundant Renewable resources Edible Biodegradable Supplement the nutritional value of foods Enhanced organoleptic characteristics of food Reduced packaging volume, weight, and waste Incorporated antimicrobial agents and antioxidants Possible use in multilayer food packaging materials together with nonedible films Extended shelf life and improved quality of usually nonpackaged items Control over intercomponent migration of moisture, gases, lipids, and solutes Individual packaging of small particulate foods Function as carriers for antimicrobial and antioxidant agents Microencapsulation and controlled release of active ingredients Based on Gennadios, A., Weller, C.L., 1990. Edible films and coatings from wheat and corn proteins. Food Technol. 44(10), 63e67; Han and Gennadios (2005); Krochta, J.M., 2002. Proteins as raw materials for films and coatings: definitions, current status, and opportunities. In: Protein-Based Films and Coatings (Gennadios, A. ed.), pp. 1e41. CRC Press, Boca Raton, FL; Guilbert, S., Cuq, B., Gontard, N., 1997. Recent innovations in edible and/or biodegradable packaging materials. Food Addit. Contam. 14(6e7): 741e751.

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packaging materials. Some biobased materials are also very attractive in appearance or pleasant to touch. This generates interesting marketing opportunities, for example, for packaging of luxury products or producing special designs. The price of these materials is generally more stable in comparison to oil-based plastics, which is a major benefit for the industry. So far, to a large extent packaging materials have been based on materials produced from nonrenewable sources. Paper and board are the most commonly used sustainable packaging materials. These are based on cellulose, which is the most abundantly available sustainable polymer. Serious efforts are being made for identifying alternative nonfood uses of agricultural crops and the production of packaging materials from the polymers obtained from these raw materials, which may become a major use of these crops (Coombs and Hall, 2000; Mangan, 1998). In actuality, such alternative biobasedpackaging materials have attracted significant R&D efforts for a long time (Coombs and Hall, 2000; Mangan, 1998). The materials are now becoming available in the market. The biological basis of the starting materials provides scientists with a unique opportunity to include an interesting functionality into the material, which is compostability. Due to this property, these materials degrade after completion of useful life. “So far, compostability has been the major focus for use of biobased packaging materials which is the logical consequence for the huge amount of packaging materials used and the production of waste associated with it. Municipal plastic waste is a difficult material as it contains several fractions of waste and plastic types containing contamination from foodstuffs resulting in labor and energy intensive recycling. Till now, prevention or increased recovery of materials has been used for extending the life of the available non-renewable materials. Recovery methods include recycling, reuse, energy recovery, composting and biomethanisation. Re-use and re-cycling of food packaging materials is difficult, because they usually contain mixtures of layers of different plastics for obtaining optimal barrier properties of the material. Caution should be also used when re-using the food contact materials, as there might be an unwanted build-up of contaminants from food components migrated into the packaging materials after re-using for several times” (documents.mx). Biomethanization by composting offers an alternative waste disposal method. Both the food packaging and the leftover food material are discarded. The hindrance in using organic recovery is the development of biobased compostable packaging having the required properties for protecting food during storage. Also, a waste infrastructure for these compostable materials along with labeling for identifying the compostable packaging should be developed. Till now, the compostability of these materials has been the main point of interest for commercialization although composting is not the widely used method for disposal in many countries. But, as the functioning of the biomaterials is being improved continuously, advanced applications are now getting within the reach.

Background and introduction

The materials that are presently being used for food packaging are derived from petroleum. These contain plastic polymers, metals, glass, paper and board, or combinations thereof. These materials and polymers are utilized in different combinations for producing materials having special properties ensuring safety and quality of food from processing and manufacturing through handling and storage and, eventually, to consumer use. These products fulfill an important task because insufficient or absence of packaging would result in rapid worsening of quality and safety, resulting in significant losses of food material. Individual food products have specific requirements for storage that the packaging materials should provide. When examining the food packaging concept, the interaction between food, packaging material, and ambient atmosphere has to be taken into consideration. Therefore, engineering of novel biobased food packaging materials is a challenging job for the industry (mis.dost.gov.ph). The biobased materials appear to be very interesting from a sustainability angle. “The question is whether they meet the standards of the materials used today or whether they even add value” (documents.mx). Biopolymers are obtained from biomass. They may be natural (e.g. cellulose), or synthetic polymers made from biomass monomers (e.g. Polylactic Acid) or synthetic polymers made from synthetic monomers derived from biomass (e.g. Polythene derived from bioethanol). Oxy-degradable plastics are not biopolymers. (www.wrap.org.uk)

Biopolymers may or may not be biodegradable. In the biodegradation process, the polymer gets converted into smaller compounds. PLA is biodegradable. Polythene obtained from bioethanol is renewable but not biodegradable. Compostable implies that a biodegradable polymer will biodegrade under standard testing conditions. A material can be composted if it is a thin film, but if the same material is thick it may not be composted. Compostability is not an inherent property of a material; it is a property of a particular form of a material. EN 13432 is a European standard for compostability. This pertains to industrial composting conditions only (www.wrap.org.uk). Development of materials from renewable raw materials for various applications has been a very important topic for many years because of environmental issues and escalating prices of petrochemicals (Laine et al., 2013; Farris et al., 2009a,b; saiapm.ulbsibiu.ro). For natural products, biopolymers enhancing the quality of products are important for satisfying the buyers preferring environment friendly packaging. This strategy is playing a predominant role in the food industry (Satyanarayana et al., 2009; Cutter, 2006). The use of polymers from sustainable raw materials in food packaging is a growing trend nowadays (Mensitieri et al., 2011). “To extend the shelf-life of foods with increasing the preservation and protection from oxidation and microbial damage the trend is to use more natural compounds. The use of synthetic films has led to serious environmental problems because these materials are non-biodegradable. The natural biopolymers used in food packaging are available from renewable resources, and are biodegradable” (Gabor and Tita, 2012; Sabiha-Hanim and Siti-Norsafurah, 2012). All these characteristics lead

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to ecological safety (Prashanth and Tharanathan, 2007). “The structure of monomer used in polymer preparation is directly effective on the properties that are required in different areas of work, such as: thermal stability, flexibility, good barrier to gases, good barrier to water, resistance to chemicals, biocompatibility, biodegradability” (G€ uner et al., 2006). Polymers obtained from natural resources can be degraded by the microbial action under different environmental conditions (Mensitieri et al., 2011). The classification of polymers has been done based on the method of production or their source (Ruban, 2009; Nampoothiri et al., 2010; Mensitieri et al., 2011; Nair et al., 2017). “Polysaccharides such as starch, and cellulose, are called biopolymers. These are natural polymers, found in nature during the growth cycles of all organisms. Other natural polymers are the proteins which can be used for producing biodegradable materials. These polymers are often chemically modified with the objective for modifying the degradation rate and improving the mechanical properties” (Vroman and Tighzert, 2009). In Table 1.2 polymers have been classified on the basis of chemical composition. Enzymes of bacteria, yeasts, and fungi can degrade biodegradable materials. The products of the degradation process under aerobic conditions are carbon dioxide, water, and biomass. Under anaerobic conditions, hydrocarbons, methane and biomass are produced (Doi and Fukuda, 1994). Thus, there is a great interest to replace some or all of the plastics by biodegradable materials in various applications. “Some of the natural polymers (PHB

Table 1.2 Classification of biopolymers depending on the general chemical composition. Biopolymers Polymers directly extracted from natural materials

Polymers synthesized from bioderived monomers

Polymers produced by microorganisms or bacteria

Polysaccharides Starch/Starch derivatives Potato, rice, corn, wheat . Cellulose/Cellulose derivatives, cotton, wood . Chitosan Pectins Proteins Animal proteins Gelatin, casein, collagen Plant proteins Wheat gluten, zein

Poly(lactic acid) Other polyesters

Polyhydroxyalkanoates Bacterial cellulose

Based on Gabor, D., Tita, O., 2012. Biopolymers used in food packaging: a review. Acta Univ. Cibiniensis. Ser. E Food Technol. 16(2), 3e19; Hu, B., 2014. Biopolymer-based lightweight materials for packaging applications, In Lightweight Materials From Biopolymers and Biofibers, Chapter 13. ACS Symposium Series, vol. 1175, pp. 239e255. https://doi.org/ 10.1021/bk-2014-1175.ch013.

Background and introduction

and its copolymers) (Gilbert, 1985) and aliphatic polyesters (polycaprolactone (Huang et al., 1990), polylactic acid (Jarowenko, 1977)) are biodegradable, but their cost compared to that of petroleum-based plastics prohibits their larger commercial utilisation and is being used only in niche areas. Among the biomaterials available commercially, are those obtained from renewable resources such as starch based products. These are the most widely used and economic biomaterials. Materbi from Novamont, Italy and Biopar from Biop. Germany are some examples. The starch is mixed with biodegradable aliphatic polyesters, such as Ecoflex from BASF Germany or Bionolle from Showa Highpolymers Japan.” Starch is stored as a reserve in most plants. It is a semicrystalline polymer and is comprised of 1,4-alpha-D glucopyranosyl units: amylose and amylopectin. The amylose is linear, in which the glucopyranosyl units are linked by alpha (1e4) linkages; the amylopectin has an alpha (1e4)-linked backbone and ca. 5% of alpha (1e6)-linked branches (Garcia et al., 2011). The amount of amylose and amylopectin are dependent upon the plant source. Corn starch generally contains about 70% amylopectin and 30% amylose (Lambert and Poncelet, 1997). The ratio of the amylase and amylopectin characterizes materials with very different properties. Starch-based materials are receiving great attention in the food packaging sector because they cost less (less than one euro per kg) and are biodegradable and widely available. Several studies have been conducted on starch-based materials (Pelissero, 1990). But there are some drawbacks with starch. It is strongly hydrophilic and the mechanical properties are inferior in comparison to traditional nonbiodegradable plastic films used in the food packaging (qcm-mazand.com). Nowadays, the use of nanocomposite concept has been found to be an attractive approach for improving mechanical and barrier properties.

References Alexandre, M., Dubois, P., 2000. Polymer-layered silicate nanocomposites: preparation, properties and use of a new class of materials. Mater. Sci. Eng. 28, 1e63. Amberg-Schwab, S., Kleebauer, M., 2007. In: Kleebauer, M., Sangl, R. (Eds.), Multifunctional Coatings With Nanoscale Polymers e An Overview, PTS Workshop Innovative Packaging, p. 8. Munich, Germany 2007, GV773. _ Andersson, C., J€arnstr€ om, L., Fogden, A., Mira, I., Voit, W., Zywicki, S., Bartkowiak, A., 2009. Preparation and incorporation of microcapsules in functional coatings for self-healing of packaging board. Packag. Technol. Sci. 22 (5), 275. Aucejo, S., 2005. Latest Developments in Fibre Based Composite Films, Pira First Sustain Pack Conference, Stockholm, Sweden, December 6e7, 2005. Avena-Bustillos, R.J., Krochta, J.M., 1993. Water vapor permeability caseinate based edible films as affected by PH. Calcium crosslinking and lipid content. J. Food Sci. 58, 904e907. Baldwin, E.A., 1994. Edible coatings for fresh fruits and vegetables: past, present and future. In: Krochta, J.M., Baldwin, E.A., Nisperos, M.O. (Eds.), Edible Coatings and Films to Improve Food Quality. Technomic publishing company, Inc., Lancaster, PA, pp. 25e64. Coombs, J., Hall, K., 2000. Non-Food Agro-Industrial Research Information. CD-Rom Version 1.2, Issue 3, 2000. CPL Publishing Services, Newbury, UK, ISBN 1-872691-27-7. ISSN 1368-6755. Cutter, C.N., 2006. Opportunities for bio-based packaging technologies to improve the quality and safety of fresh and further processed muscle foods. Meat Science 74 (1), 131e142.

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De Vlieger, J.J., 2003. Green plastics for food packaging. In: Ahvenainen, R. (Ed.), Novel Food Packaging Techniques. Woodhead Publishing Ltd., Cambridge, UK, pp. 519e534. Doi, Y., Fukuda, K. (Eds.), 1994. Biodegradable Plastics and Polymers. Elsevier, Amsterdam, pp. 479e497. Farris, S., Schaich, K.M., Liu, L.S., Piergiovanni, L., Yam, K.L., 2009a. Development of polyion-complex hydrogels as an alternative approach for the production of bio-based polymers for food packaging applications: a review. Trends Food Sci. Technol. 20 (8), 316e332. Farris, S., Introzzi, L., Piergiovanni, L., 2009b. Evaluation of a bio-coating as a solution to improve barrier, friction and optical properties of plastic films. Packag. Technol. Sci. 22 (2), 69e83. Franz, R., Welle, F., 2003. Recycling packaging materials. In: Ahvenainen, R. (Ed.), Novel Food Packaging Techniques. Woodhead Publishing Ltd., Cambridge, UK, pp. 497e518. Gabor, D., Tita, O., 2012. Biopolymers used in food packaging: a review. Acta Univ. Cibiniensis. Ser. E Food Technol. 16 (2), 3e19. Garcia, N.L., Ribba, L., Dufresne, A., Aranguren, M., Goyanes, S., 2011. Effect of glycerol on the morphology of nanocomposites made from thermoplastic starch and starch nanocrystals. Carbohydr. Polym. 84 (1), 203e210, 11. Gennadios, A., Weller, C.L., 1990. Edible films and coatings from wheat and corn proteins. Food Technol. 44 (10), 63e67. Gennadios, A., Brandenburg, A.H., Weller, C.L., Testin, R.F., 1993. Effect of pH on properties of wheat gluten and soy protein isolate films. J. Agric. Food Chem. 41, 1835e1839. Gennadios, A., Rhim, J.W., Handa, A., Weller, C.L., Hanna, M.A., 1998. Ultraviolet radiation affects physical and molecular properties of soy. Protein films. J. Food Sci. 63, 225e228. Ghorpade, V.M., Li, H., Gennadios, A., Hanna, M.A., 1995. Chemically modified soy protein films. Trans. Am. Soc. Agric. Eng. 38, 1805e1808. Giannelis, E.P., 1996. Polymer layered silicate nanocomposites. Adv. Mater. 8, 29e35. Gilbert, S.G., 1985. Food/package compatibility. Food Technol. 39, 54e56. Global Packaging Alliance- http://www.global-packaging-alliance.com/. Gontard, N., Duchez, C., Cuq, J.L., Guilbert, S., 1994. Edible composite films of wheat gluten and lipids: water vapor permeability and other physical properties. Int. J. Food Sci. Technol. 29, 39e50. Guilbert, S., Cuq, B., Gontard, N., 1997. Recent innovations in edible and/or biodegradable packaging materials. Food Addit. Contam. 14 (6e7), 741e751. G€ uner, F., Yagci, Y., Erciyes, A.T., 2006. Polymers from triglyceride oils. Prog. Polym. Sci. 31 (7), 633e670. Gustafsson, M., Stoor, R., Tsvetkova, A., 2011. Sustainable Bio-economy: Potential, Challenges and Opportunities in Finland. PBI Research Institute. Han, J.H., 2000. Antimicrobial food packaging. Food Technol. 54 (3), 56e65. Han, J.H., Gennadios, A., 2005. Edible films and coatings: A review. In: Han, J.H. (Ed.), Innovations in Food Packaging. Elsevier, London, UK, pp. 239e262. Hohenthal, C., Veuro, S., 2011. In: The Role of LCA in Guiding Projects, FlexPakRenew Workshop, Lyon, France, May 10, 2011, No. 3. Hu, B., 2014. Biopolymer-based lightweight materials for packaging applications. In: Lightweight Materials from Biopolymers and Biofibers, Chapter 13. ACS Symposium Series, vol. 1175, pp. 239e255. https:// doi.org/10.1021/bk-2014-1175.ch013. Huang, J.C., Shetty, A.S., Wang, M.S., 1990. Biodegradable plastics: a review. Adv. Polym. Technol. 10, 23e30. Jacobsson, S., 2008. The emergence and troubled growth of a bio-power innovation system in Sweden. Energy Policy 36, 1491e1497. Jarowenko, W., 1977. Encyclopedia of Polymer Science and Technology, vol. 12. Interscience, New York. Jelse, K., Eriksson, E., Einarson, E., 2011. Life Cycle Assessment of Consumer Packaging for Liquid Food. IVL, Swedish Environmental Research Institute. www.tetrapak.com. Johansson, C., Bras, J., Mondragon, I., Nechita, P., Plackett, D., Simon, P., Svetec, D.G., Virtanen, S., Baschetti, M.G., Breen, C., Clegg, F., Aucejo, S., 2012. Renewable fibers and bio-based materials for packaging applications e a review of recent developments. Bio Resour. 7 (2), 2506e2552. Kester, J., Fennema, O., 1986. Edible films and coatings: a review. Food Technol. 40 (12), 47e59.

Background and introduction

Krochta, J.M., 2002. Proteins as raw materials for films and coatings: definitions, current status, and opportunities. In: Gennadios, A. (Ed.), Protein-Based Films and Coatings. CRC Press, Boca Raton, FL, pp. 1e41. Laine, C., Harlin, A., Hartman, J., Hyv€arinen, S., Kammiovirta, K., Krogerus, B., Pajari, H., Rautkoski, H., Set€al€a, H., Siev€anen, J., Uotila, J., V€ah€a-Nissi, M., 2013. Hydroxyalkylated xylans e their synthesis and application in coatings for packaging and paper. Ind. Crops Prod. 44, 692e704. Lambert, J.F., Poncelet, G., 1997. Acidity in pillared clays: origin and catalytic manifestations. Top. Catal. 4, 43e56. Mangan, C. (Ed.), 1998. The Green Chemical and Polymers Chain. European Commission, DG12, DG6, Luxenbourg. Office for Official Publications of the European Union, Belgium, ISBN 92-828-6116-3. Mensitieri, G., Di Maio, E., Buonocore, G.G., Nedi, I., Oliviero, M., Sansone, L., Iannace, S., 2011. Processing and shelf life issues of selected food packaging materials and structures from renewable resources. Trends Food Sci. Technol. 22 (2e3), 72e80. Micard, V., Belamri, R., Morel, M.H., Guilbert, S., 2000. Properties of chemically and physically treated wheat gluten films. J. Agric. Food Chem. 48, 2948e2953. Nair, N.R., Sekhar, V.C., Nampoothiri, K.M., Pandey, A., 2017. Biodegradation of biopolymers. In: Current Developments in Biotechnology and Bioengineering, Chapter 32. Elsevier BV, p. 739. Nampoothiri, M.K., Nair, N.R., Rojan, P.J., 2010. An overview of the recent developments in polylactide (PLA) research. Bioresour. Technol. 101 (22), 8493e8501. Pandey, J.K., Kumar, A.P., Misra, M., Mohanty, A.K., Drzal, L.T., Singh, R.P., 2005. Recent advances in biodegradable nanocomposites. J. Nanosci. Nanotechnol. 5, 497e526. Park, H., Weller, C., Vergano, P., Testin, R., 1993. Permeability and mechanical properties of cellulose based edible films. J. Food Sci. 58 (6), 1361e1364. Parker, G., 2008. Measuring the environmental performance of food packaging: life cycle assessment. In: Chiellini, E. (Ed.), Environmentally Compatible Food Packaging. Woodhead Publishing Ltd., Cambridge, UK, pp. 211e237. Pelissero, A. (Ed.), 1990. Le materie plastiche e lambiente. AIM, Bologna, pp. 129e138. Prashanth, K.V.H., Tharanathan, R.N., 2007. Chitin/chitosan: modifications and their unlimited application potentialdan overview. Trends Food Sci. Technol. 18 (3), 117e131. Rhim, J.W., 2004. Physical and mechanical properties of water resistant sodium alginate films. Lebensm. Wiss. Technol. 37, 323e330. Rhim, J.W., Ng, P.K., 2007. Natural biopolymer-based nanocomposite films for packaging applications. Crit. Rev. Food Sci. Nutr. 47 (4), 411e433. Rhim, J.W., Gennadios, A., Weller, C.L., Cezeirat, C., Hanna, M.A., 1998. Soy protein isolate-dialdehyde starch films. Ind. Crops Prod. 8, 195e203. Rhim, J.W., Gennadios, A., Dejing, F., Weller, C.L., Hanna, M.A., 1999. Properties of ultraviolet irradiated protein films. Lebensm. Wiss. Technol. 32, 129e133. Rhim, J., Gennadios, A., Handa, A., Weller, C., Hanna, M., 2000. Solubility, tensile, and color properties of modified soy protein isolate films. J. Agric. Food Chem. 48 (10), 4937e4941. Rhim, J.W., Weller, C.L., 2000. Properties of formaldehyde adsorbed soy protein isolate films. Food Sci. Biotechnol. 9, 228e233. Robertson, G., 2008. State-of-the-art biobased food packaging materials. In: Chiellini, E. (Ed.), Environmentally Compatible Food Packaging. Woodhead Publishing Ltd., Cambridge, UK, pp. 3e28. Ruban, S.W., 2009. Biobased packaging e application in meat industry. Vet. World 2 (2), 79e82. Sabiha-Hanim, S., Siti-Norsafurah, A.M., 2012. Physical properties of hemicellulose films from sugarcane bagasse. Procedia Eng. 42, 1390e1395. August. Satyanarayana, K.G., Arizaga, G.G.C., Wypych, F., 2009. Biodegradable composites based on lignocellulosic fibersdan overview. Prog. Polym. Sci. 34 (9), 982e1021. Schmidt, D., Shah, D., Giannelis, E.P., 2002. New advances in polymer/layered Silicate nanocomposites. Curr. Opin. Solid State Mater. Sci. 6, 205e212. Sinha Ray, S., Okamoto, M., 2003a. Polymer/layered silicate nanocomposites: a review from preparation to processing. Prog. Polym. Sci. 28 (11), 1539e1641.

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Sinha Ray, S., Okamoto, M., 2003b. Biodegradable polylactide and its nanocomposites: opening a new dimension for plastics and composites. Macromol. Rapid Commun. 24, 815e840. Sinha Ray, S., Yamada, K., Okamoto, M., Ueda, K., 2003a. Biodegradable polylactide/montmorillonite nanocomposites. J. Nanosci. Nanotechnol. 3, 503e510. Sinha Ray, S., Yamada, K., Okamoto, M., Ogami, A., Ueda, K., 2003b. New polylactide/layered silicate nanocomposites. Part II: concurrent improvements of material properties, biodegradability and melt rheology. Polymer 44, 857e866. Sinha Ray, S., Yamada, K., Okamoto, M., Fujimoto, Y., Ogami, A., Ueda, K., 2003c. Newpolylactide/ layered silicate nanocomposites part III: high-performance biodegradable materials. Chem. Mater. 15, 1456e1465. Tariq, S., 2013. Success Factors for the Adoption of Bio- Based Packaging in EU Food Industry. Master of Science Thesis. Stockholm, Sweden 2013. U.S. Congress, Office of Technology Assessment, 1993. Biopolymers: Making Materials Nature’s WayBackground Paper. OTA-BP-E-102. U.S. Government Printing Office, Washington, DC. Vaia, R.A., Gianelis, E.P., 1997. Lattice model of polymer melt intercalation in organically-modified layered silicates. Macromolecules 30, 7990e7999. Vroman, I., Tighzert, L., 2009. Biodegradable polymers. Materials 2 (2), 307e344. Weber, C. (Ed.), 2000a. The Food Biopack Conference Proceedings, Copenhagen, Denmark, August 27e29, 2000. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-09-7. Weber, C. (Ed.), 2000b. Biobased Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0. Wellenreuther, F., von Falkenstein, E., Detzel, A., 2010. Comparative life cycle assessment of beverage cartons cb3 and cb3 EcoPlus for UHT milk, ifeu-institut f€ ur Energie- und Umwetforschung Heidelberg GmbH. www.sig.biz. Wong, W.S., Camirand, W.P., Pavlath, A.E., 1994. Development of edible coatings for minimally processed fruit and vegetables. In: Krochta, J.M., Baldwin, E.A., Nisperos-Carriedo, M.O. (Eds.), Edible Coatings and Films to Improve Food Quality. Technomic Pub. Co, Lancaster, PA, pp. 65e88. www. sustainabledevelopment2015.org/AdvocacyToolkit/ ... /92-our-common-future. Yu, Y.H., Lin, C.Y., Yeh, J.M., Lin, W.H., 2003. Preparation and properties of poly(vinyl alcohol)-clay nanocomposite materials. Polymer 44 (12), 3553e3560.

Relevant websites www.sustainabledevelopment2015.org/AdvocacyToolkit/.../92-our-common-future. mis.dost.gov.ph. qcm-mazand.com. saiapm.ulbsibiu.ro. www.wrap.org.uk. documents.mx.

CHAPTER 2

Description of biobased polymers Contents 2.1 Challenges 2.2 Biobased polymers in packaging References Relevant websites

17 18 20 23

Biobased polymers are sustainable polymers produced from renewable resources such as biomass instead of the conventional fossil resources such as petroleum and natural gas, preferably based on biological and biochemical processes. They are characterized by the nature of carbon neutral or carbon offset in which the atmospheric carbon dioxide concentration does not increase even after their incineration Masutani and Kimura, 2015 Global production capacity for biopolymers increased by 4%e6.6 million tonnes from 2015 to 2016. This represents a share of 2% of the global polymer market. The turnover of bio-based polymer was about Vuro13 billion worldwide in 2016 compared to Vuro11 billion in 2014. Production capacity of bio-based polymers is forecasted to increase 8.5 million tonnes by 2021. In 2016, it was 6.6 million tonnes (http://news.bio-based.eu/bio-based-polymers-worldwide-ongoinggrowth-despite-difficult-market-environment; www.mdpi.com)

All types of biopolymers are not biodegradable, but some are. Examples are starch blends, polyhydroxyalkanoates (PHAs) and polylactic acid (PLA). The most important development is envisaged for PHA. “This belongs to the large family of different polymers. PHA production capacity was small in 2016 and is expected to increase three times by 2021. Another important development is predicted for polyamides (PA); its production capacity is expected to increase two times by 2021. Bio drop-in PET and bio PLA are showing about 10% annual growth rates” (http://news.biobased.eu/biobasedpolymers-worldwide-ongoing-growth-despite-difficult-market-environment). Several definitions are used for biopolymers in the polymer, packaging, and composite areas. The term “bio” is used for designating a biodegradable material, and also used for designating materials from sustainable raw materials. The European Bioplastics Association uses a broader definition referring to different types of bioplastics (Table 2.1) ( Johansson et al., 2012). Criteria used for sorting biopolymers are presented in Table 2.2.

Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00002-3

© 2019 Elsevier Inc. All rights reserved.

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Biobased Polymers

Table 2.1 Bioplastics (European Bioplastics Association).

1. Bioderived and biodegradable/compostable polylactides, polyhydroxyalkanoates 2. Fossil fuelederived and biodegradable polycaprolactone 3. Bioderived and nonbiodegradable Biopolyethylene (bio-PE) and biopolyethylene terephthalate (bio-PET). A bioderived polymer such as bio-PE is chemically identical to PE derived from oil, and therefore has the same chemical and physical characteristics. Based on Johansson, C., Bras, J., Mondragon, I., Nechita, P., Plackett, D., Simon, P., Svetec, D.G., Virtanen, S., Baschetti, M.G., Breen, C., Clegg, F., Aucejo, S. 2012. Renewable fibers and bio-based materials for packaging applications e a review of recent developments. Bio Resour. 7(2), 2506e2552.

Table 2.2 Criteria used for sorting biopolymers.

Chemical composition Method of synthesis Method of processing Economic importance Application areas Based on Johansson, C., Bras, J., Mondragon, I., Nechita, P., Plackett, D., Simon, P., Svetec, D.G., Virtanen, S., Baschetti, M.G., Breen, C., Clegg, F., Aucejo, S. 2012. Renewable fibers and bio-based materials for packaging applications e a review of recent developments. Bio Resour. 7(2), 2506e2552.

Biopolymers can be grouped into three categories according to their origin (Petersen et al., 1999): 1. Polymers produced from natural products such as polysaccharides 2. Polymers produced by traditional chemical synthesis from sustainable biomonomers (example PLA) 3. Polymers produced by microorganisms or genetically modified bacteria. Examples are PHAs. These comprise polyhydroxybutyrate (PHB) and copolymers of hydroxybutyrate and hydroxyvalerate). Polysaccharidesdcellulose and starchdare called biopolymers. These are natural polymers found in nature during the growth of all organisms. Other naturally occurring polymers are the proteins that can be used for producing materials that can be biodegraded (U.S. Congress, 1993). These polymers are usually chemically modified with an objective for modifying the degradation rate and improving the mechanical properties (Vroman and Tighzert, 2009). Natural polymers are being used as barrier coatings in paper packaging materials. These can replace synthetic paper coatings being currently used, such as polyethylene, polyvinyl alcohol, rubber latex, and fluorocarbon in food packaging (Chan and Krochta, 2001a,b). “Agriculturally derived products to synthetic paper coatings provide an

Description of biobased polymers

opportunity for strengthening the agricultural economy and reducing import of petroleum and its derivatives” (Khwaldia et al., 2010). A number of companies have introduced different types of biopolymers. Table 2.3 lists their manufacturers, brands, and main packaging applications. According to the materials they are manufactured from, these biopolymers can also be classified as starch polymers (e.g., Mater-Bi), cellulosic (e.g., cellophane), aliphatic polyesters (e.g., PLA), biobased polyethylene (bio-PE), and microbial synthesized polyhydroxyalkanoates (e.g., PHB). In studying the biodegradation of polymers an important difference should be made between degradation and biodegradation. Usually, materials exposed to weathering, aging, and/or burying will undergo chemical, mechanical and thermal transformations. These conditions result in the change of structure of polymers and its properties, and can be an important factor in initiating the biodegradation process. Instances of compression, tension, shear, and other forces may lead to the mechanical degradation of a material. These factors do not play a predominant role in the biodegradation process but can stimulate or sustain it Pan et al., 2013; Khosravi-Darani and Bucci, 2015

Table 2.3 Manufacturers of biopolymers. Polymers

Manufacturers

Brand

Applications

Starch

DuPont Biotec Novamont Innovia films Eastman Chemical FKuR Sateri BASF NatureWorks Cargill dow Synbra DuPont

Biomax Bioplast Mater-Bi Natureflex Tenite

Loose fill, bags, films, trays, wrap film

Biograde Sateri Ecovio Ingeo EcoPLA Biofoam Biomax

Braskem

BioPE

Monsanto Biomer

Biopol Biomer

Cellulosics

Polylactic acid (PLA)

Biobased polyethylene terephthalate (PET) Biobased polyethylene (PE) Polyhydroxyalkanoates (PHAs) and polyhydroxybutyrate (PHB)

Flexible film

Rigid containers, films, barriers Bottles, trays, films Rigid containers, film wrap, barrier coatings Films, barrier coatings, trays

Based on Hu, B., 2014. Biopolymer-based lightweight materials for packaging applications. In Lightweight Materials from Biopolymers and Biofibers, Chapter 13. ACS Symposium Series, vol. 1175, pp. 239e255. https://doi.org/10.1021/bk2014-1175.ch013. Mohanty, A.K., Misra, M., Hinrichsen, G., 2000. Biofibres, biodegradable polymers and biocomposites an overview. Macromol. Mater. Eng., 276e277, 1e24, Mohanty, A.K., Misra, M., Drzal, L.T., 2002. Sustainable biocomposites from renewable resources opportunities and challenges in the green materials world. J. Polym. Environ. 10, 19e26.

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Biobased Polymers

Various polymers that are able to biodegrade can be used in packaging; some biodegradable polymers are already being used. Cellophane is the commonly used cellulosebased biopolymer and is used in food packaging (Lu et al., 2014; Pan et al., 2013). Starch-based polymers have the tendency to swell. These polymers when exposed to moisture get deformed. Other interesting biopolymers are PLAs, PHA, PHB, and a copolymer of PHB and valeric acid (Marsh and Bugusu, 2007). But, inferior mechanical properties, higher hydrophilic nature, and restricted ability to be processed are limiting their use (Wang et al., 2015). As sustainable solutions to our future requirements for energy and materials are in focus, the renewability of biopolymers is an important issue in our society ( Johansson et al., 2012). The biodegradability of certain types of polymers will be important for some material applications. Biodegradability is an ideal aspect for a sustainable material to keep the loop of cradle to grave closed for plastics used (Shen et al., 2009; Natureworks, 2009; Weiss et al., 2007). Ecofriendly and biodegradable polymers are being developed because of environmental issues and studies of end-of-life of materials presently used in packaging and other fields (Oksman et al., 2006; Pandey et al., 2005; Shahzad Tariq 2013; Abdul-Muhmin, 2007; Lee et al., 2008; Ballesteros et al., 2018). Problems of waste disposal associated with plastics derived from petroleum are reduced by the use of biodegradable polymers (Mohanty et al., 2000). Despite the fact that totally replacing the traditional plastics by biodegradable materials does not look feasible at the moment, there are certain applications for which such a replacement appears to be useful. The term biodegradation has not been used consistently (van der Zee, 2005). Biodegradation means fragmentation, reduction of mechanical properties, or sometimes degradation by the microbes for plastics that are degradable. Several international organizations and groups have developed methods for determining biodegradability and compostability under different environmental conditions (Mohanty et al., 2000). There are many reasons why the use of a single definition has not been easy (van der Zee, 2005). Some of which are presented below ( Johansson et al., 2012): • The variation of the definitions because of the differences in the environment in which the material is introduced • Different viewpoints related to biodegradability • Different viewpoints on the policy implications of the different definitions Several excellent reviews and books have been published on polymers (Petersen et al., 1999; Chandra and Rustgi, 1998; Witt; et al., 1997; Guilbert et al., 1996; Krochta and Mulder-Johnston, 1997; Gabor andTita, 2012; Babu et al., 2013). According to ASTMeD883-00, biodegradable polymers go through substantial changes in their chemical structure under certain conditions ( Johansson et al., 2012). This results in a loss of physical and mechanical properties. Biodegradable polymers

Description of biobased polymers

degrade by enzymes or microorganisms. There are two steps for assuring that a material can be biodegraded: 1. Physicochemical degradation of the material 2. Assimilation by microorganisms for obtaining water and oxygen, carbon dioxide or methane The EN 13432 on composting and biodegradation is well accepted for testing the biodegradability of packaging material ( Johansson et al., 2012). This is based on the following guidelines: • Low amount of heavy metals • Disintegration (breaking of the material so that after 12 weeks in a compost, less than 10% of the initial material must have size greater than 2 mm when the final product is passed through 2 mm) • In accordance with ISO test methods (ISO 14851, ISO 14852, ISO 14855), 90% of the initial weight should be absorbed in less than 6 months • The properties of the final product as determined by ecotoxicology tests “Polymers may be photobiodegradable, oxidatively degradable, hydrolytically degradable, or compostable” (van der Zee, 2005; Kolybaba et al., 2003). These terms may lead to confusion. Therefore, to avoid this problem, researchers are using Life-cycle assessment (LCA) and carbon footprint evaluations for examining the environmental impact of the packaging materials. A range of environmental aspects are covered in LCA. Carbon footprint focuses on the global warming covering the environmental impacts from packaging and has been found to be beneficial for biopolymers (Parker, 2008). Use of oxo-degradable polyolefins, which are being used in shopping bags, is now in question as there can be hazard from the smaller plastic fragments that are left when these products are discarded. Ammala et al. (2011) have reviewed degradable and biodegradable polyolefins.

2.1 Challenges PLAs have made the largest impact in the market for packaging materials. However, extensive research has been devoted to other biopolymers such as starch, chitosan, proteins, and PHAs. The advantages of biopolymers when compared with traditional plastics are biodegradability and availability from sustainable raw materials. The latter is more important when it comes to large-scale utilization. But this point of view is now complicated by the availability of nondegradable bio-PE obtained from sugar cane ( Johansson et al., 2012). There are certain challenges (related to processability or to final properties) in using biopolymers in packaging. For instance, melt processing of PLA needs less moisture. As shown by the products available in the market, this can be achieved. The barrier properties of PLA are not enough for food packaging applications and efforts are being made

17

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Biobased Polymers

to improve these properties. Several studies have been conducted on nanocomposites, involving use of layered silicate additives. With this method, the barrier properties of PLA have been improved. Though reduction in oxygen permeability of 50%e60% at 23 C and 50% relative humidity are expected, this is not adequate for wider application of PLA in foods containing high moisture (Katiyar et al., 2011). “The additives make PLA films more brittle as compared to that in their unmodified form. Methods of obtaining better barrier properties using layer-by-layer coating or other nano-additives or combinations of these methods appear interesting. Combination of biopolymers with nanofillers and their use in food packaging is also now raising questions regarding the migration of nanoparticles and their toxicological properties (Schmidt et al., 2009; Sharma et al., 2010). Increased application of PLA in packaging could benefit from cost-efficient techniques for introducing better mechanical properties and higher thermal stability.” The use of biodegradable polymers in packaging is expected to benefit from better understanding of these materials from an angle of waste management and also from research focused on the environmental impact of bioplastics. The latter implies requirement for improved LCA applied to commercial bioplastics under development.

2.2 Biobased polymers in packaging In the recent years, naturally renewable biopolymers are being researched due to interest in their use as edible and biodegradable films and coatings for food packaging. Several research groups have reviewed the properties and uses of biopolymer films and coatings (Kester and Fennema, 1986; Gennadios et al., 1994; Gontard and Guilbert, 1994; Krochta et al., 1994; Anker, 1996; Guilbert et al., 1997; Krochta and De MulderJohnston, 1997; Krochta, 2002; Khwaldia et al., 2004). Biopackaging materials produced from sustainable raw materials such as polysaccharides, proteins, and lipids or their combinations can be recycled and reutilized in comparison to traditional synthetic polymers obtained from petroleum. Biopolymer films and coatings may also act as barriers and complement other types of packaging by reducing the spoilage of food and increasing the shelf life (Guilbert et al., 1996; Krochta and De Mulder-Johnston, 1997; Debeaufort et al., 1998). Furthermore, these films and coatings can act as effective vehicles for using several additives and nutrients (Baldwin, 1994; Petersen et al., 1999; Ozdemir and Floros, 2001; Han and Gennadios, 2005). The inclusion of biobased biopolymers to paper provides interesting properties while maintaining environment-friendly nature of the material. Renewable biopolymers, such as caseinates (Rhim and Ng, 2007; Khwaldia et al., 2005; Gastaldi et al., 2007; Khwaldia, 2010), whey protein isolate (Han and Krochta, 1999, 2001; Lin and Krochta, 2003; G€ allstedt et al., 2005; Hong et al., 2004), isolated soy protein (Park et al., 2000; Rhim et al., 2006), wheat gluten (G€ allstedt et al., 2005), corn zein (Trezza and Vergano, 1994; Parris et al., 1998; Trezza et al., 1998), chitosan (Despond

Description of biobased polymers

et al., 2005; Ham-Pichavant et al., 2005; Kjellgren et al., 2006), carrageenan (Rhim et al., 1998), alginate (Rhim et al., 2006), and starch (Matsui et al., 2004) have been examined as papercoating materials (Johansson et al., 2012). Whey-protein-coated paper improves performance of packaging paper by increasing oil resistance and reducing permeability of water-vapor (Han and Krochta, 1999, 2001). Rhim et al. (2006) found that water resistance can be improved by coating of paper with soy protein isolate (SPI) or alginate. Despond et al. (2005) and Kjellgren et al. (2006), used paper coated with chitosan or chitosan/carnauba wax for obtaining a packaging material showing good barrier properties Khwaldia, 2010

Xylan obtained from birch pulp in combination with reinforcing nanoclays showed good barrier properties when used on a low-grammage paper (Talja and Poppius-Levlin, 2011). Good oxygen barrier properties of hemicelluloses have been observed, but hygroscopicity and high water vapor permeability is usually expected. The properties of biocomposites produced from xylan and Montmorillonite clay were examined by € u et al. (2009). They suggested that some intercalation of xylan in the clay galleries Unl€ could occur depending on concentration. The xylans with nanocellulose combination could also offer an attractive approach to sustainable biodegradable films, which can be used in the food packaging sector (Saxena and Ragauskas, 2009; Saxena et al., 2009). Albertsson et al. (2011) have published a review of hemicellulose synthesis, chemistry, and properties, which included information on application of hemicelluloses in the area of food packaging. For packaging applications, starch and proteins can be used as biodegradable films and coatings (Pan and Caballero, 2011), which may be used for protecting fruits and nuts from damage, for reducing the shrinkage of the fruits, and reducing rancidity of nuts. Kafirin is one of the sustainable materials that appears to be suitable for such films and coatings (Stading, 2003). This protein is found in sorghum and available as a byproduct when sorghum is processed. Cast films from kafirin showed water vapor barrier properties that were much better to those of the films obtained from whey protein (Stading, 2003), but barrier properties were comparable to those of zein (Gillgren and Stading, 2008). In the presence of a plasticizer, kafirin films showed adequate mechanical strength properties (Gillgren and Stading, 2008). In paper-coating formulations, acrylic hybrid latexes based on vegetable oil macromonomers showed higher hydrophobic property and reduced migration of surfactants in comparison to commercial carboxylated styrene-acrylic latexes (Rawlins et al., 2009). Another approach is corn starch latex, for which several applications have been reported (Klass, 2007). Composite films of a gelatin-based coating showed better barrier properties against oxygen and ultraviolet radiation (Farris et al., 2009). Potential uses for fish gelatin films reinforced with montmorillonite clay and the effect of parameters such as homogenization speed, pH and ultrasonication on film properties were reported Bae et al., 2009

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References Abdul-Muhmin, A.G., 2007. Explaining consumers’ willingness to be environmentally friendly. Int. J. Consum. Stud. 31, 237e247. Albertsson, A.C., Edlund, U., Varma, I.K., 2011. Synthesis, chemistry and properties of hemicelluloses. In: Plackett, D. (Ed.), Biopolymers e New Materials for Sustainable Films and Coatings. John Wiley & Sons Ltd, Chichester, West Sussex, UK. Chapter 7. Ammala, A., Bateman, S., Dean, K., Petinakis, E., Sangwan, P., Wong, S., Yuan, Q., Yu, l, Patrick, C., Leong, K.H., 2011. An overview of degradable and biodegradable polyolefins. Prog. Polym. Sci. 36, 1015e1049. Anker, M., 1996. Edible and Biodegradable and Coatings for Food Packaging Literature Review. SIK teborg, Plastic Material. Report no. 623, GoE Babu, R.P., O’Connor, K., Seeram, R., 2013. Current progress on bio-based polymers and their future trends. Prog. Biomater. 2 (8), 1e16. Bae, H.J., Park, H.J., Hong, S.I., Byun, Y.J., Darby, D.O., Kimmel, R.M., Whiteside, W.S., 2009. Effect of clay content, homogenisation RPM, pH and ultrasonication on mechanical and barrier properties of fish gelatine/montmorillonite nanocomposite films. LWT e Food Sci. Tech. 42, 1179e1186. Baldwin, E.A., 1994. Edible coatings for fresh fruits and vegetables: past, present, and future. In: Krochta, J.M., Baldwin, E.A., Nisperos-Carriedo, M.O. (Eds.), Edible Coatings and Films to Improve Food Quality. Technomic Publishing Co. Inc, Lancaster, Pa, pp. 25e64. ^ 2018. Lignocellulosic Ballesteros, L.F., Michelin, M., Vicente, A.A., Teixeira, J.A., Cerqueira, M.A., Materials and Their Use in Biobased Packaging. Springer Nature. Chan, M.A., Krochta, J.M., 2001a. Grease and oxygen barrier properties of whey-protein-isolate coated paperboard. Tappi J. 84, 57. Chan, M.A., Krochta, J.M., 2001b. Color and gloss of whey-protein coated paperboard. Tappi J. 84, 58. Chandra, R., Rustgi, R., 1998. Biodegradable polymers. Prog. Polym. Sci. 23, 1273e1335. Debeaufort, F., Quezada-Gallo, J.A., Voilley, A., 1998. Edible films and coatingsdtomorrow’s packaging: a review. Crit Rev Food Sci 38, 299e313. Despond, S., Espuche, N., Cartier, N., Domard, A., 2005. Barrier properties of paper-chitosan and paperchitosan-carnauba wax films. J. Appl. Polym. Sci. 98, 704e710. Farris, S., Introzzi, L., Piergiovanni, L., 2009. Evaluation of a bio-coating as a solution to improve barrier, friction and optical properties of plastic films. Packag. Technol. Sci. 22 (2), 69e83. Gabor, D., Tita, O., 2012. Biopolymers used in food packaging: a review. Acta Univ. Cibiniensis. Ser. E Food Technol. 16 (2), 3e19. Gastaldi, E., Chalier, P., Guillemin, A., Gontard, N., 2007. Microstructure of protein-coated papers affected by physico-chemical properties of coating solutions. Colloids Surf. A 301, 301e310. Gennadios, A., McHugh, T., Weller, C.L., Krochta, J.M., 1994. Edible coatings and films based on proteins. In: Krotcha, J.M., Baldwin, E.A., Nisperos-Carriedo, M.O. (Eds.), Edible Coatings and Films to Improve Food Quality. Technomic Publishing Co. Inc, Lancaster, PA. Gillgren, T., Stading, M., 2008. Mechanical and barrier properties of avenin, kafirin and zein films. Food Biophys. 3, 287e294. Gontard, N., Guilbert, S., 1994. Biopackaging: technology and properties of edible and/or biodegradable materials of agricultural origin. In: Mathlouthi, M. (Ed.), Food Packaging and Preservation. Blackie Academic & Professional, London, pp. 159e181. Guilbert, S., Gontard, N., Gorris, L.G.M., 1996. Prolongation of the shelf life of perishable food products using biodegradable films and coatings. Lebensm. Wiss. Technol. 29, 10e17. Guilbert, S., Cuq, B., Gontard, N., 1997. Recent innovations in edible and/or biodegradable packaging materials. Food Addit. Contam. 14, 741e751. G€allstedt, M., Brottman, A., Hedenqvist, M.S., 2005. Packaging-related properties of protein- and chitosancoated paper. Packag. Technol. Sci. 18, 161e170. Ham-Pichavant, F., Sebe, G., Pardon, P., Coma, V., 2005. Fat resistance properties of chitosan-based paper packaging for food applications. Carbohydr. Polym. 61 (3), 259e265.

Description of biobased polymers

Han, J.H., Gennadios, A., 2005. Edible films and coatings: a review. In: Han, J.H. (Ed.), Innovations in Food Packaging. Elsevier Academic Press, London, pp. 239e262. Han, J.H., Krochta, J.M., 1999. Wetting properties and sodium water vapor permeability of whey-proteincoated paper. Trans. Am. Soc. Agric. Eng. 42, 1375e1382. Han, J.H., Krochta, J.M., 2001. Physical properties and oil absorption of whey-protein-coated paper. J. Food Sci. 66, 294e299. Hong, S.I., Han, J.H., Krochta, J.M., 2004. Optical and surface properties of whey protein isolate coatings on plastic films as influenced by substrate, protein concentration, and plasticizer type. J. Appl. Polym. Sci. 92 (1), 335e343. Hu, B., 2014. Biopolymer-based lightweight materials for packaging applications. In: Lightweight Materials from Biopolymers and Biofibers, Chapter 13. ACS Symposium Series, vol. 1175, pp. 239e255. https:// doi.org/10.1021/bk-2014-1175.ch013. Johansson, C., Bras, J., Mondragon, I., Nechita, P., Plackett, D., Simon, P., Svetec, D.G., Virtanen, S., Baschetti, M.G., Breen, C., Clegg, F., Aucejo, S., 2012. Renewable fibers and bio-based materials for packaging applications e a review of recent developments. Bio Resour. 7 (2), 2506e2552. Katiyar, V., Gerds, N., Koch, C.B., Risbo, J., Hansen, H.C.B., Plackett, D., 2011. Melt processing of poly(L-lactic acid) in the presence of organomodified anionic or cationic clays. J. Appl. Polym. Sci. 122, 112e125. Kester, J.J., Fennema, O.R., 1986. Edible films and coatings: a review. Food Technol. 40 (12), 47e59. Khosravi-Darani, K., Bucci, D.Z., 2015. Application of poly(hydroxyalkanoate) in food packaging improvements by nanotechnology. Chem. Biochem. Eng. Q. 29, 275e285. Khwaldia, K., 2010. Water vapor barrier and mechanical properties of paper sodium caseinate and papere sodium caseinateeparaffin wax films. J. Food Biochem. 34, 998e1013. Khwaldia, K., Arab-Tehrany, E., Desobry, S., 2010. Biopolymer coatings on paper packaging materials. Compr. Rev. Food Sci. Food Saf. 9, 82e92. Khwaldia, K., Perez, C., Banon, S., Desobry, S., Hardy, J., 2004. Milk proteins for edible films and coatings. Crit. Rev. Food Sci. Nutr. 44, 239e251. Khwaldia, K., Linder, M., Banon, S., Desobry, S., 2005. Combined effects of mica, carnaubawax, glycerol and sodium caseinate concentrations on water vapor barrier and mechanical properties of coated paper. J. Food Sci. 70, E192eE197. Kjellgren, H., G€allstedt, M., Engstr€ om, G., J€arnstr€ om, L., 2006. Barrier and surface properties of chitosancoated greaseproof paper. Carbohydr. Polym. 65, 453e460. Klass, C.P., 2007. New nanoparticles latex offers natural advantage. Paper 360 30e31. Jan. 2007. Kolybaba, M., Tabil, L.G., Panigrahi, S., Crerar, W.J., Powell, T., Wang, B. (Eds.), 2003. Biodegradable Polymers: Past, Present, and Future, CSAE/ASAE Annual Intersectional Meeting, Fargo, USA, 2003. ASAE, Fargo, USA, 2003, 3. Krochta, J.M., 2002. Proteins as raw materials for films and coatings: definitions, current status, and opportunities. In: Gennadios, A. (Ed.), Protein-based Films and Coatings. CRC Press, Boca Raton, Fla.; London; New York; Washington, D.C, pp. 1e32. Krochta, J.M., De Mulder-Johnston, C., 1997. Edible and biodegradable polymer films. Challenges and opportunities. Food Technol. 51, 61e74. Krochta, J.M., Baldwin, E.A., Nisperos-Carriedo, M.O., 1994. Edible Coatings and Films to Improve Food Quality. Technomic Publishing Co. Inc, Lancaster, PA. Lee, J.W., Son, S.M., Hong, S.I., 2008. Characterization of protein-coated polypropylene films as a novel composite structure for active food packaging application. J. Food Eng. 86 (4), 484e493. Lin, S.Y., Krochta, J.M., 2003. Plasticizer effect on grease barrier and color properties of whey-protein coatings on paperboard. J. Food Sci. 68 (1), 229e233. Lu, P., Xiao, H., Zhang, W., Gong, G., 2014. Reactive coating of soybean oil-based polymer on nanofibrillated cellulose film for water vapor barrier packaging. Carbohydr. Polym. 111, 524e529. Marsh, K., Bugusu, B., 2007. Food packaging -Roles, materials, and environmental issues. J. Food Sci. 12, 39e55.

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Masutani, K., Kimura, Y., 2015. PLA Synthesis. In: Jimenez, A., Peltzer, M., Ruseckaite, R. (Eds.), From the Monomer to the Polymer In Poly(lactic acid) Science and Technology. Processing, Properties, Additives and Applications. Print ISBN: 978-1-84973-879-8. Matsui, K.N., Larotonda, F.D.S., Paes, S.S., Luiz, D.B., Pires, A.T.N., Laurindo, J.B., 2004. Cassava bagasseKraft paper composites: analysis of influence of impregnation with starch acetate on tensile strength and water absorption properties. Carbohydr. Polym. 55, 237e243. Mohanty, A.K., Misra, M., Hinrichsen, G., 2000. Biofibres, biodegradable polymers and biocomposites an overview. Macromol. Mater. Eng. 276-277, 1e24. Mohanty, A.K., Misra, M., Drzal, L.T., 2002. Sustainable bio-composites from renewable resources opportunities and challenges in the green materials world. J. Polym. Environ. 10, 19e26. NatureWorks, 2009. The Ingeotm Journey. NatureWorks LLC whitepaper. Available at: http://www. natureworksllc.com/w/media/News_and_Events/NatureWorks_TheIngeoJourney_pdf.pdf. Oksman, K., Mathew, A.P., Bondeson, D., Kvien, I., 2006. Manufacturing process of cellulose whiskers/ polylactic acid nanocomposites. Compos. Sci. Technol. 66, 2776e2784. Ozdemir, M., Floros, J.D., 2001. Analysis and modeling of potassium sorbate diffusion through edible whey protein films. J. Food Eng. 47, 149e155. Pan, I.F., Caballero, J.I.M., 2011. Biopolymers for edible films and coatings in food applications. In: Plackett, D. (Ed.), Biopolymers e New Materials for Sustainable Films and Coatings. John Wiley & Sons Ltd, Chichester, West Sussex, UK. Chapter 11. Pan, Y., Wang, M.Z., Xiao, H., 2013. Biocomposites containing cellulose fibers treated with nanosized elastomeric latex for enhancing impact strength. Compos. Sci. Technol. 77, 81e86. Pandey, J.K., Kumar, A.P., Misra, M., Mohanty, A.K., Drzal, L.T., Singh, R.P.J., 2005. Recent advances in biodegradable nanocomposites. J. Nanosci. Nanotechnol. 4, 497e525. Park, H.J., Kim, S.H., Lim, S.T., Shin, D.H., Choi, S.Y., Hwang, K.T., 2000. Grease resistance and mechanical properties of isolated soy protein-coated paper. J. Am. Chem. Soc. 77, 269e273. Parker, G., 2008. Measuring the environmental performance of food packaging: life cycle assessment. In: Chiellini, E. (Ed.), Environmentally Compatible Food Packaging. Woodhead Publishing Ltd., Cambridge, UK, pp. 211e237. Parris, N., Vergano, P.J., Dickey, L.C., Cooke, P.H., Craig, J.C., 1998. Enzymatic hydrolysis of zeinwaxcoated paper. J. Agric. Food Chem. 46, 4056e4059. Petersen, K., Nielsen, P.V., Bertelsen, G., Lawther, M., Olsen, M.B., Nilsson, N.H., Mortensen, G., 1999. Potential of biobased materials for food packaging. Trends Food Sci. Technol. 10, 52e68. Rawlins, J.S., Ferguson, R.C., Stockett, A.S., Dutta, S., Delatte, D.E., 2009. Synthesis of alkyd/acrylic hybrid latexes for papers coating applications. Tappi J. 18e23. June 2009. Rhim, J.W., Ng, P.K.W., 2007. Natural biopolymer-based nanocomposite films for packaging applications. Crit. Rev. Food Sci. Nutr. 47, 411e433. Rhim, J.W., Hwang, K.T., Park, H.J., Kang, S.K., Jung, S.T., 1998. Lipid penetration characteristics of carrageenan-based edible films. Korean. J. Food Sci. Technol. 30, 379e384. Rhim, J.W., Lee, J.H., Hong, S.I., 2006. Water resistance and mechanical properties of biopolymer (alginate and soy protein) coated paperboards. Lebensm. Wiss. Technol. 39, 806e813. Saxena, A., Ragauskas, A.J., 2009. Water vapor transmission properties of biodegradable films based on cellulosic whiskers and xylan. Carbohydr. Polym. 78, 357e360. Saxena, A., Elder, T.J., Pan, S., Ragauskas, A.J., 2009. Novel nanocellulosic xylan composite film. Compos. B Eng. 40, 727e730. Schmidt, B., Petersen, J.H., Bender Koch, C., Plackett, D., Johansen, N.R., Katiyar, V., Larsen, E.H., 2009. Combining asymmetrical flow field-flow fractionation with light-scattering and inductively coupled plasma mass spectrometric detection for characterization of nanoclay used in biopolymer nanocomposites. Food Addit. Contam. A 26, 1619e1627. Sharma, A.K., Schmidt, B., Frandsen, H., Jacobsen, N.R., Larsen, E.H., Binderup, M.L., 2010. Genotoxicity of unmodified and organomodified montmorillonite. Mutat. Res. Genet. Toxicol. Environ. Mutagen 700, 18e25. Shen, L., Worrell, E., Patel, M., 2009. Present and future development in plastics from biomass. Biofuels, Bioprod. Bioref. 4, 25e40. Society of Chemical Industry and John Wiley & Sons, Ltd. Stading, M., 2003. Environment-friendly packaging solutions for enhanced storage and quality of Southern Africa’s fruit and nut exports. In: Belton, P.S., Taylor, J.R.N. (Eds.), AFRIPRO, Workshop on the

Description of biobased polymers

Proteins of Sorghum and Millets: Enhancing Nutrition and Functional Properties for Africa. Pretoria, South Africa, April 2e4, 2003. www.afripro.org.uk. Talja, R., Poppius-Levlin, K., 2011. Xylan from wood biorefinery e a novel approach. In: FlexPakRenew Workshop, Lyon, France, May 10, 2011, p. 5. Tariq, S., 2013. Success Factors for the Adoption of Bio- Based Packaging in EU Food Industry. Master of Science Thesis. Stockholm, Sweden 2013. Trezza, T.A., Vergano, P.J., 1994. Grease resistance of corn zein-coated paper. J. Food Sci. 59, 912e915. Trezza, T.A., Wiles, J.L., Vergano, P.J., 1998. Water vapor and oxygen barrier properties of corn zein-coated paper. Tappi J. 81, 171e176. € u, C., Gunister, E., Atici, O., 2009. Synthesis and characterization of NaMt biocomposites with corn cob Unl€ xylan in aqueous media. Carbohydr. Polym. 76, 585e592. U.S. Congress, Office of Technology Assessment, 1993. Biopolymers: Making Materials Nature’s WayBackground Paper. OTA-BP-E-102. U.S. Government Printing Office, Washington, DC. van der Zee, M., 2005. Biodegradability of polymers - mechanisms and evaluation methods. In: Bastioli, C. (Ed.), Handbook of Biodegradable Polymers. Rapra Technology Ltd, Shawbury, UK, pp. 1e22. Vroman, I., Tighzert, L., 2009. Biodegradable polymers. Materials 2 (2), 307e344. Wang, H., Wei, D., Ziaee, Z., Xiao, H., Zheng, A., Zhao, Y., 2015. Preparation and properties of nonleaching antimicrobial linear low-density polyethylene films. Ind. Eng. Chem. Res. 54, 1824e1831. Wiess, M., Patel, M., Heilmer, H., Bringezu, S., 2007. Applying distance to target weighing methodology to evaluate the environmental performance of bio-based energy fuels and materials. Resour. Conserv. Recycl. 50, 260e281. Witt, U., M€ uller, R.J., Klein, J., 1997. Biologisch abbaubare Polymere. Status und Perspektiven. Franz.Patat-Zentrum, Braunsweig, Germany, ISBN 3-00-001529-9.

Relevant websites www.mdpi.com. http://news.bio-based.eu/bio-based-polymers-worldwide-ongoinggrowth-despite-difficult-marketenvironment.

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CHAPTER 3

Properties of biobased packaging material Contents 3.1 Biobased natural polymers 3.1.1 Starch 3.1.2 Cellulose 3.1.3 Chitin and chitosan 3.1.4 Pullulan 3.1.5 Alginates 3.1.6 Carrageenan 3.1.7 Xanthan 3.1.8 Dextrans 3.1.9 Pectin 3.1.10 Glucans 3.1.11 Gellan 3.1.12 Collagen 3.1.13 Gelatin 3.1.14 Soy protein 3.1.15 Whey protein 3.1.16 Zein 3.1.17 Casein 3.1.18 Gluten 3.2 Polymers produced from traditional chemical synthesis from biobased monomers 3.2.1 Polylactic Acid 3.2.2 Polybutylene succinate 3.2.3 Biopolyethylene 3.2.4 Polyhydroxyalkanoates References Further reading Relevant websites

26 26 33 39 42 45 47 50 52 55 57 58 59 60 63 65 66 68 70 72 72 79 82 84 89 110 110

Biobased polymers usually have a reduced carbon dioxide footprint and are associated with the concept of sustainability (Babu et al., 2013). Due to issues about the exhaustion of fossil resources and the global warming associated with the use of petrochemicals, new biobased products are being developed (Johansson et al., 2012; Shahzad Tariq, 2013). Biobased products are preferred through initiatives such as BioPreferred (USA) and the Lead Market Initiative (European Union). Consequently, serious efforts are being made to replace raw materials derived from petroleum with raw materials derived from Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00003-5

© 2019 Elsevier Inc. All rights reserved.

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Biobased Polymers

Table 3.1 Biobased polymers produced by various processes. Production of biobased polymers

Polymers from agro sources Polysaccharides and lipids

From microorganisms Polyhydroxy alkanoates

From biotechnology via conventional synthesis Polylactides Poly(butylene succinate) (PBS) Polyethylene (PE) Poly(trimethylene terephthalate) (PTT) Poly(pphenylene) (PPP)

Based on Luc, A., Eric, P., 2012. Environmental Silicate Nano-Biocomposites. Green Energy and Technology. Biodegradable polymers, Springer, Hiedelberg. 13e39.

renewable resources for the production of polymers. In recent years, biopolymers have shown significant growth both in terms of technological advances and their industrial applications. The first generation of biopolymers focused on obtaining polymers from agricultural substrates, for instance, corn and potatoes and other types of carbohydrates. In recent years the emphasis has shifted because of the wish to move away from food-based resources and substantial advancements in the area of biotechnology (Babu et al., 2013). Biopolymers are produced by fermentation using microorganisms by synthesizing the building blocks (monomers) from sustainable raw materials, including lignocellulosic feedstocks and organic waste and fatty acid. Natural biopolymers are found naturally and are the other class of biopolymers. These include, for example, polysaccharides (chitin, chitosan, collagen, etc.), proteins, and nucleic acids. As described in Chapter 2, three methods are used for producing biobased polymers using sustainable raw materials: using natural biopolymers with partial modification for meeting the requirements, e.g., starch; production of biomonomers by fermentation/conventional chemistry followed by polymerization, e.g. polylactic acid (PLA), polybutylene succinate (PBS), and polyethylene (PE); and producing biopolymers by bacteria, e.g., polyhydroxyalkanoates (PHAs) (Table 3.1).

3.1 Biobased natural polymers These consist of starch, cellulose, chitin, chitosan, and several other polysaccharides and proteins. These polymers occur naturally and offer a wide range of properties and applications. This chapter discusses the natural biobased polymers and their applications.

3.1.1 Starch Starch is a natural polymer. It is a product of photosynthesis obtained from carbon dioxide and water (Teramoto et al., 2003). Starch is low cost and renewable. Therefore, it is a good candidate for developing sustainable materials (Zhang and Sun, 2004). It is

Properties of biobased packaging material

completely biodegradable (Ara ujo et al., 2004). Because of this, starch has received increasing attention since the 1970s (Griffin, 1994; Pareta and Edirisinghe, 2006). Considerable efforts are being made for developing starch-based polymers to save petrochemical resources, reduce damaging environmental impact, and explore more applications (Park et al., 2004; Schwach and Averous, 2004; Stepto, 2006). Starch is suitable for several industrial uses (Le Corre, 2011). It is found in nature as discrete granules and is made up of the elements carbon, hydrogen, and oxygen. Plants synthesize and accumulate starch as an energy reserve. Starch is found in the leaves, stems, shoots, and storage organs such as tubers (i.e., potato, cassava), rhizomes, and seeds. Starch can be obtained from several sources like wheat, corn, potatoes, rice, barley, and sorghum. Corn is the major source of starch, while large quantities of starch are produced from potato, wheat, and rice in the United States, Europe, and Asia. In the higher plants, starch is the major carbohydrate storage product. Starch actually refers to materials having a wide range of structures and properties. The main source of starch for industrial and food application is corn. Starch essentially contains the polysaccharide amylose, which is linear, and generally 20%e30% amylopectin, which is a highly branched polysaccharide and is generally 70%e80%. The amylose is linear and helical, while amylopectins are branched. Amylose has a small amount of side branches (9e20 per macromolecule), which contains up to 6000 glucose residues joined by a-1,4-glycoside bonds (Fig. 3.1). The molecular weight of amylose is within the range of 105 to 106. Amylopectins are very large, branched polymers of glucose, containing between one and two million residues. They consist of several amylose-like chains of up to 30 glucose units joined through alpha (1e4) bonds, connected to one another through alpha (1e6) branch point. Amylopectin has a molecular weight about 1000 times greater, of 105 to 106, and a strongly branched main chain. The side branches are produced by the alpha1,6-glycoside linkage (Fig. 3.2) (Hoover, 2001). The distance between the adjacent branches is commonly equal to 20e25 units of alpha-D-glucose (Manners, 1989). Microscopy studies and X-ray crystallography have shown the amylopectin framework within the starch granules to be crystalline and organized in separated concentric rings as observed in cross sections (French, 1984). Amylose is more resistant to digestion as compared to other starch molecules due to its tightly packed helical structure. Therefore, it is an important form of resistant starch. The

Figure 3.1 Structure of amylose.

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Biobased Polymers

Figure: 3.2 Structure of amylopectin.

percentage of amylose to amylopectin and alpha-(1/6) branch points depends on the starch source (corn, wheat, rice, and potato, etc.). For example, amylomaizes contain more than 50% amylose whereas “waxy” maize has very little (w3%) (Li and Yeh, 2001; Singh et al., 2003). The ratio of amylose and amylopectin imparts starch-based polymers with very different properties. High ratio of amylopectin results in an increase of solubility of starch due to the highly branched polymer, whereas amylose is insoluble and hydrolyzes very slowly (U.S Congress Publications, 1993). Amylose acts as a hydrocolloid. Its extended conformation results in the high viscosity of water-soluble starch and varies comparatively very little with temperature. The extended loosely coiled chains have a hydrophobic inner surface that does not hold water well, and the more hydrophobic molecules can replace this easily. Amylose is able to form useful gels and films. On cooling and storage, starch retrogrades, which reduces its storage stability resulting in contraction and the release of water. The increase of the amylose concentration reduces the stickiness but increases the firmness of gels. Retrogradation is affected by the following factors (Chung and Liu, 2009): • Amylose to amylopectin ratio • Chain length of amylose and amylopectin • Solid and lipid content “Amylopectin interferes with the interaction between amylose chains (and retrogradation) and its solution can lead to an initial loss in viscosity and followed by a more slimy consistency. Amylopectins also partially crystallize and form gels through double helical structures with external chains of adjacent molecules. Both external and internal chains form helical inclusion complexes [that] give rise to effects on the functional properties of the starch, with apparently small differences in the length of segments having significant effects on gelling” (Bertoft et al., 2016; www1.lsbu.ac.uk).

Starches obtained from the various sources have different qualities. Starches vary in ratio of amylose to amylopectin, film-forming properties, size and shape of grain, and temperature of gelatinization. The rheological properties of the pasted starches vary greatly (Lineback David, 1984). Starch from different sources can be physically separated under a microscope, each having its own characteristics when pasted and cast as a film.

Properties of biobased packaging material

Starch is usually deposited in the form of small granules or cells varying in shape and size and having different physicochemical and functional characteristics (Tharananthan, 1995). The diameters of small starch granules are between 1 and 100 mm (Wurzburg, 1986). Starch granules is a natural way for storing energy in green plants over long times. These granules are insoluble in water and compactly packed but still accessible to the plants’ metabolic system. So, these granules are well suited for this role. Starch granules can be easily isolated from different sources by wet milling processes (Whistler and Daniel, 2005; Eckhoff et al., 1996). Thermoplastic starch is becoming popular within the industry. These polymers accumulate in plants as energy storage granules that are not soluble. Each granule contains two polymers. Plant breeding methods are being used for producing new strains having different amount of amylose and amylopectin. In waxy corn only 0.8% amylose is present, whereas in contrast natural corn contains 28% amylose. In amylomaize up to 80% amylose can be present. The manipulation of the amylose and amylopectin ratio by strain development has substantially reduced the costs of separation of the two polymers. This is quite essential as the properties and applications of amylose and amylopectin are different. The properties of starch vary widely and depend on the amount of plasticizer present. The modulus is similar to polyolefins, and Tg (glass transition temperature) varies in the range of 50 C to 110 C ( Jane, 1995). Many challenges are faced in producing starch plastics. The structure of starch is partly nonlinear and complex leading to problems with ductility. Starches suffer from retrogradation. This is an increase in crystallinity with time, which leads to high brittleness. There is a requirement to identify plasticizers for developing starch plastics having properties comparable to packaging obtained from polyolefin. Plasticized starch blends and composites and/or chemical modifications can solve these problems. These are able to produce biodegradable polymers having enough flexibility, strength, and barrier properties for commercial packaging and consumer products (Maurizio et al., 2005). Starch-based materials are the economic biomaterials and are most widely used. Starch is blended into several products due to its low cost and availability. Around 60% starch is used in food and the remaining 40% for industrial applications (Table 3.2) (Le Corre et al., 2011). The starch is either used as “native starch” or “modified starch.” Native starch is extracted from the plant. Modified starch is obtained when chemical modifications on native starch are performed. But, most starches in the native form present certain limitations. Because of this, most granular starch used in different applications is first modified. Modification of starches (chemical and/or physical) is done for the following reasons: • To highlight their positive characteristics • To reduce their undesirable characteristics like high viscosity, tendency to retrograde, and lack of process tolerance • To include new properties such as film formation, retention, digestibility, solubility, etc.

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Biobased Polymers

Table 3.2 Applications of starch products.

Confectionery and drink Processed food Feed (animals) Other nonfood Pharmaceuticals and chemicals Corrugated and paper making

32% 29% 1% 4% 6% 28%

Based Le Corre-Bordes, Deborah., Bras, J., Dufresne, A., 2011. Influence of botanic origin and amylose content on the morphology of starch nanocrystals. J. Nanoparticle Res. https://doi.org/10.1007/s11051-011-0634-2(12).

Table 3.3 presents properties and applications of modified starches. A number of useful derivatives can be produced by chemical modification of starch. Currently, the World Agricultural Supply and Demand has forecasted that consumption of corn for ethanol production is 5.475 billion bushels, higher by 36 million bushels from 2016 to 2017 marketing year estimates (https://www.usda.gov/oce/commodity/ wasde/latest.pdf ). To exceed this projection is feasible, but demand for ethanol will be Table 3.3 Properties and applications of modified starches.

Acid-modified

Cross-linked

Decreased hot-paste viscosity compared to unmodified starches Reduced peak viscosity, increased paste stability

Acetylated (ester)

Excellent paste clarity and stability, good freeze-thaw stability; hydrophobic for high degree of substitution (DS)

Phosphate monoesters (ester)

Reduced gelatinization temperature, reduced retrogradation

Hydroxypropylated (ether)

Increased paste clarity, reduced retrogradation, good freezethaw stability

Textile sizing agent; binding material in cardboard making Ingredients in antiperspirants and textile printing paste; oil well drilling mud, printing ink, charcoal briquette binders, fiberglass sizing, and textile sizing. Low DS: wrap sizing in textiles, forming sizes, and surface sizing in papermaking. High DS: thermoplastic molding and plasticizer Wet end additives in papermaking; sizes in textile (polyester) and thickeners in textile printing inks. Surface sizing and wet ends in papermaking; Low DS: as wrap sizing in textiles

Based on Deborah Le Corre, 2011. Starch Nanocrystals: Preparation and Application to Bio-Based Flexible Packaging. Material chemistry. Universite de Grenoble; Daniel, J.R., Whistler, R.L., R€ oper, H., 2007. Starch. In Ullmann’s Encyclopedia of Industrial Chemistry, Wiley, Ed. VCH Verlag GmbH & Co.

Properties of biobased packaging material

important as we move ahead (www.prairiefarmer.com). An additional several billion pounds of corn starch is utilized for nonfuel applications. About 75% of the industrial cornstarch is converted into adhesives that are used in the paper, paperboard, and related industries. Cornstarch is able to absorb up to 1000 times its weight in moisture. Therefore, it is used in diapers (about 200 million pounds annually), for treating burns, and in fuel filters for the removal of water. Cornstarch is used as stabilizers, thickeners, soil conditioners, and even road deicers (U.S Congress Publications, 1993). Starch has attracted significant attention because of its biodegradable nature or replacement material in conventional oil-based commodity plastics. Several types of starch plastic blends have been included in packaging and garbage bags, but there is disagreement as to whether these composites can biodegrade. Starch itself is able to degrade easily, and in actuality it is one of major components of the biological food chain. When starch is mixed with polyethylene (petroleum-derived polymer), it speeds up the breaking of the synthetic polymer chains. Starch is consumed by microorganisms, producing pores in the material, which weakens it and eventually breaks it. Several researchers have wrongly described this process as a form of biodegradation. Studies of starch-polyethylene blends show that the starch can biodegrade but the polymer will not biodegrade at any substantial rate. Breakdown of polyethylenestarch blends is not the same as biodegradation. Furthermore, degradation rates vary significantly under different environmental conditions. In landfills, the degradation rates are very slow even for easily degradable materials. Under optimum conditions, degradation of starch-plastic blends containing less than 30% starch is very slow. Some studies have shown that the starch composition should be more than 60% before significant degradation takes place. New biodegradable materials have now been developed containing higher percentages of starch. Starch can be mixed with water and other compounds for creating a resin alike to crystalline polystyrene. The NOVON family of polymers introduced by Warner-Lambert contain 40%e98% starch and easily gets dissolved. These resins combine starch with other biodegradable materials and show degradation similar to lignocellulosic materials. Properties can be changed by changing the composition of starch and other material components. They are able to substitute traditional plastics used in food packaging and food service, personal health care, agricultural, and outdoor markets. NOVON polymers have been used in loose-fill packaging, agricultural mulch films, pharmaceutical capsules, compost bags, and cutlery. The manufacturing was started in 1992. The materials were developed for markets where the benefits of their biodegradability could be shown. The cost of these starch-based resins is two to four times higher than commodity resins. Their unique properties might lead to the development of new specialty markets. Novamont is a leader in the area of processing starch-based products (Li et al., 2009) and is selling four classes of materials, A, Z, V, and Y, under the Mater-Bi trademark. These contain starch and differ in their synthetic components (Bastioli, 1998).

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Table 3.4 Suppliers of starch-based products.

Novamont, Italy Japan Corn Starch, Japan Biotec, Germany Rodenberg, Netherlands BIOP, Germany Plantic, Australia Wuhan Huali Environment Protection Science and Technology, China Biograde, China PSM, USA Livan, Canada Based on Doug, S. 2010 Bioplastics: Technologies and Global Markets. BCC research reports PLS050A. http://www.bccresearch.com/report/bioplastics-technologiesmarkets- pls050a. htm, Ravenstijn, J.T.J., 2010. The State-Of-The Art on Bioplastics: Products, Markets, Trends and Technologies. Polymedia, L€ udenscheid.

Other companies are also producing starch-based products for several applications. These are presented in Table 3.4 (Doug, 2010; Ravenstijn, 2010). “Applications of thermoplastic starch polymers include films for packing materials. shopping, bread, and fishing bait bags, overwraps, flushable sanitary product and special mulch films. Potential future applications could include loose-fill packaging and injection-molded products such as ‘take-away’ food containers. Starch and modified starches have a broad range of applications both in the food and non-food sectors” (Huber and Be Miller, 2010; Daniel et al., 2007; paperity.org). The consumption of starch and starch derivatives was approximately 7.9 million tons in Europe in 2002. For food applications 54% was used, and in other applications 46% was used (Frost and Sullivan report 2009). In the European Union (EU), paper, paperboard, and corrugating industries are the largest users of starch (30%) (Frost and Sullivan report, 2009). Starch is also used in textiles, cosmetics, pharmaceuticals, construction, and paints (Ashammakhi and Rokkanen, 1997; Mainil et al., 1997; Mendes et al., 2001; Marques and Reis, 2005 Espigares et al., 2002 Jaspreet et al., 2007; Fuentes et al., 2010; Asha and Martins, 2012; Zhao et al., 2008; Maurizio et al., 2005; Ozdemir and Floros, 2004; Guo et al., 2005; Kumbar et al., 2001; Li et al., 2011). “Starch will play an increasing role in the field of renewable raw materials for the production of biodegradable plastics, packaging material, and molded products” (paperity.org). Starch-based polymers, such as Mater-Bi and modified starch, are receiving significant attention in the food packaging applications because these are widely available, biodegradable, and the cost is low (Avella et al., 2005). It can be used in coating for packaging applications and bioresorbable films. There are also some drawbacks with the use of starch. These include hydrophilic behavior (poor moisture barrier) and poor mechanical

Properties of biobased packaging material

properties in comparison to the conventional nonbiodegradable polymer-based films used in the food packaging ( Johansson et al., 2012). The morphology and the properties of starch-based polymers can be changed by mixing with synthetic polymers. Paper industry is the largest sector utilizing nonfood starch. Starch is used in paper making process in the wet end and in surface sizing and coating. Both modified and unmodified starches are used for coating. Starch is used in paper as filler as it increases the paper’s firmness. Starch is used for increasing the paper strength, smoothness, or the sheet surface.

3.1.2 Cellulose Cellulose is an abundantly available, renewable polymer available worldwide. It is a complex polysaccharide. Cellulose synthesis by plants is around 1012 tons annually (Klemm et al., 1998). Cellulose content is about 33% in plants, 50% in wood, and 90% in cotton (Krassig, 1993). Cellulose is an important feedstock for several industries, and a range of useful cellulose products can be produced by incorporating functional groups to the basic glucose building blocks of cellulose. The elemental composition of cellulose was determined by Payen in 1835. Cellulose contains 44%e45% carbon, 6%e6.5% hydrogen, and the remainder is oxygen. The empirical formula was determined to be C6H10O5. But, the structure was not clear. Chain-like macromolecular structure was proposed by Haworth in the 1920s, and Staudinger presented the highly polymeric nature of cellulose in 1960 (Haworth, 1928, 1932; Staudinger, 1960). Cellulose has a crystalline morphology and functions as a reinforcement material in plants and bacteria (Pandey et al., 2012). It is an almost linear and moderately stiff homopolymer containing D-anhydroglucopyranose (AGU) units. Because of its arrangement of hydroxyl groups and its regular structure, it forms strongly hydrogen-bonded crystalline microfibrils and fibers. Cellulose is different from starch. In cellulose, glucose units are joined by beta-1,4glycosidic bonds, while in starch, bonds are mainly alpha-1,4 linkages. These chains have the ability to bond together into fibers imparting cellulose chemical stability and mechanical strength. AGU units in cellulose are joined by beta-(1 / 4) glycosidic bonds formed between C-1 and C-4 of adjacent glucose moieties (Fig. 3.3) (Granstr€ om, 2009). AGU units are rotated by 180 with respect to each other because of the constraints of betalinkage in the solid state. All the AGU units have three hydroxyl groups at C-2, C-3 and C-6 positions. Terminal groups at the either end of the cellulose molecule are quite different in nature from each other. The C-1 OH at one end of the molecule is an aldehyde group showing reducing activity. Aldehyde groups form a pyranose ring through an intramolecular hemiacetal form. In contrast, the C-4 OH on the other end of the chain is an alcohol borne OH constituent and thus is called the non-reducing end. Infrared spectroscopy (IR), X-ray crystallography and nuclear

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Biobased Polymers

Figure 3.3 Molecular structure of cellulose representing the cellobiose unit as a repeating unit. (Based on Haworth, W.N., 1932. Die konstitution einiger kohlenhydrate. Ber. Dtsch. Chem. Ges. 65, 43.)

magnetic resonance (NMR) investigations have shown that the AGU ring exists in the pyranose ring form and that this adopts the 4C1-chair formation which constitutes the lowest energy conformation for D-glucopyranose. (Brown and Ley,1965; Chu Shirley and Jeffrey, 1968: Berman and Kim, 1968; Mitchell 1970; Koch and Peterlin, 1970; Ham and Williams, 1970; Ellefsen and Tonnesen, 1971; Rao et al., 1967; helda. helsinki.fi).

Cellulose is the major constituent of plant cell wall and imparts structural support. It is also found in algae, fungi, and bacteria. Cellulose is a polymer of beta-D-glucopyranose moieties when existing as unbranched, homopolymer. These are joined via beta-(1,4) glycosidic bonds with well-documented polymorphs (Fig. 3.3). The degree of polymerization of cellulose chains ranges from 10,000 glucopyranose units in wood to 15,000 in native cotton. The repeating unit of the cellulose chain is cellobiose which is disaccharide as oppose to glucose in other glucan polymers (Desvaux, 2005; Fengel and Wegener, 1984). The cellulose chains (20e300) are grouped together to form microfibrils, which are bundled together to form cellulose fibers. The long-chain cellulose polymers are linked by hydrogen and Van der Waals bonds, which cause the cellulose to be packed into microfibrils. Hemicelluloses and lignin cover the microfibrils. D-glucose can be produced from cellulose by using either acid or enzymes breaking the beta-(1,4) glycosidic linkages. In biomass, cellulose is present in both crystalline and amorphous forms. Cellulose is susceptible to enzymatic attack in its amorphous form. The cellulose microfibrils are mostly independent. Crystalline cellulose contains the major proportion of cellulose. In the amorphous cellulose, a small proportion of unorganized cellulose chains are present. The ultrastructure of cellulose is mainly due to the presence of covalent bonds, hydrogen bonds, and Van der Waals forces. Hydrogen bonding within a cellulose microfibril determines ‘straightness’ of the chain but interchain hydrogen bonds might introduce order or disorder into the cellulose structure (Laureano-Perez et al., 2005; Bajpai, 2016).

Cellulose represents an organized architecture of fibrillar elements. The fibril has a diameter of about 3.5 nm. It is the smallest morphological unit (Fengel and Wegener, 1989). Wide-angle X-ray scattering and electron microscopy data show that the diameter varies in the range of 3e35 nm depending on the source of cellulose (Chanzy et al., 1986). Microfibril is the lowest morphological entity, although it consists of nonuniform

Properties of biobased packaging material

subunits. “The length of the microfibril can reach micrometers, which forms the macrofibrils having diameter in the range of micrometers. Microfibril and macrofibril represent the construction units of the cellulose fiber cell-wall architecture, characterized by layers having different fibril texture. The fibers consist of different layers, with the fibril position giving different textures and densities. The diameter of primary wall fibrils is about 10 nm and are positioned crosswise to a layer having a thickness of about 50 nm. The secondary cell wall consists of two layers which are termed as S1 and S2 layers. Thickness is about 100 nm (cotton) to 300 nm (spruce pulp). Most of the cellulose mass is present in the S1 and S2 layers. The fibrils are aligned in parallel. These are packed densely in a flat helix. The inner layer which is nearest to the fiber lumen is the tertiary layer. This layer is thin and the fibrils are aligned in a flat helix”(Klemm et al., 2005; Fengel and Wegner, 1989; Kr€assig, 1993). Cellulose is isolated in the form of microfibrils. It is able to undergo enzymatic degradation to produce glucose. Cellulose is a linear polymer but it is insoluble in common solvents because of the presence of hydrogen bond between the polymer chains. Cellulose is used for several purposes. It has been used as a construction material, mostly in the form of intact wood, textile fibers, and paper and board. It is also an all-around starting material for chemical conversions, for production of artificial cellulose-based threads and films, and also stable cellulose derivatives that have several uses in industry (Klemm et al., 1998). The important feedstocks for producing cellulosic plastics are wood and cotton fibers. Cellulose is dissolved in caustic soda and carbon disulfide to produce viscose, which is reconverted to cellulose in cellophane form following treatment with sulfuric acid and sodium sulfate. Sulfite and prehydrolysis kraft pulping processes are used for separating cellulose from lignin and hemicellulose (Yan et al., 2009). High pressure and chemicals are used for the separation of cellulose, achieving higher than 97% cellulose purity. Cellulose is a hard polymer. The major cellulose derivatives are cellulose acetate, cellulose esters (molding, extrusion, and films), and regenerated cellulose for fibers. The tensile strength of cellulose is 62e500 MPa and elongation is 4% (Bisanda and Ansell, 1992; Eichhorn et al., 2001). For overcoming the processing problems of cellulose, it is important that cellulose should be modified, plasticized, and blended with other polymers. The properties are found to vary from blend to blend depending on the composition. The Tg of cellulose derivatives ranges from 53 to 180 C (Picker and Hoag, 2002). The main producer of cellulose derivatives is Eastman Chemical. FKuR started business in the year 2000 and has a production capacity of 2800 metric tons/year of various cellulose derivatives (Doug, 2010). Table 3.5 lists the global suppliers of cellulose-based compounds (Doug, 2010; Ravenstijn, 2010). The major groups of cellulosic polymers are cellulose esters (cellulose acetate). These are considered as potentially useful for packaging. Cellulose acetate is synthesized through the reaction of acetic anhydride with cotton linters or wood pulp (Mohanty et al., 2000).

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Biobased Polymers

Table 3.5 Global suppliers of cellulosic products.

Innovia Films, UK Eastman Chemical, USA FKuR, Germany Sateri, China

Nature flex Tenite Biograde Sateri

Based on Doug, S. 2010 Bioplastics: Technologies and Global Markets. BCC research reports PLS050A. http://www.bccresearch.com/report/bioplastics-technologiesmarkets- pls050a.htm, Ravenstijn, J.T.J., 2010. The State-Of-The Art on Bioplastics: Products, Markets, Trends and Technologies. Polymedia, L€ udenscheid.

Biopolymer-based cellulose acetate is produced by Mazzucchelli (Italy) and Planet polymer (USA) under the trade name of BIOCETA and EnviroPlastic, respectively. Both of them are manufacturing biodegradable packaging films, containers, and tubes (Mohanty et al., 2000). The important cellulose ethers are carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC). These are used in construction, food, personal care, pharmaceuticals, paints, etc. (Kamel et al., 2008). Regenerated cellulose finds application in fiber and films. These fibers are used in textiles, home furnishing fabrics, and disposables due to its thermal stability and modulus (Kevin et al., 2001). Pure cellulose can be produced using certain types of bacteria. Bacterial cellulose is pure and has a high strength. Bacterial cellulose is used in food and biomedical fields. Other applications are in the areas of mining, paints, oil gas recovery, adhesives, and acoustic diaphragms. The price of bacterial cellulose is high. Polyethylene or wax coated paper is used in certain areas of primary food packaging, but most of the paper is used for secondary packaging. Cellulose is an inexpensive feedstock, but is difficult to use. It has a crystalline structure and is hydrophilic and insoluble. For producing cellophane film, cellulose is dissolved in mixture of caustic soda and carbon disulphide and then recast into sulphuric acid. Cellophane is hydrophilic and possess[es] good mechanical properties. It is not thermoplastic due to the reason that the melt temperature is above the degradation temperature, and so cannot be heat-sealed. Nitrocellulose wax or Poly Vinylidene Chloride are used to coat Cellophane to improve the barrier properties. Cellophane is used for packaging of baked goods, processed meat, cheese and candies. There is significant potential for the development of improved cellulose film products. (www.bc.bangor.ac.uk; Weber, 2000)

Several derivatives of cellulose (Table 3.6) are being produced commercially. Cellulose acetate is extensively used in food packaging. Cellulose acetate needs to be plasticized for film production and has relatively low gas and moisture barrier properties. The film-forming properties of cellulose derivatives are excellent, but cannot be used on a large scale for commercial reasons (Lavoine et al., 2012). This is because of the crystalline structure of cellulose making derivatization difficult and expensive. R&D is

Properties of biobased packaging material

Table 3.6 Manufacturers producing cellulose-based polymer films for packaging.

Eastman Tenite www.eastman.com Mazzuchelli1849 BIOCETA www.mazzucchelli1849.it Innovia films Natureflex www.films.ucb-group.com Based on miller-klein.com/wp-content/uploads/2016/12/2007LandscapeforBiopolymers.pdf.

needed for developing effective technologies for producing cellulose derivatives if this situation is to change. Cellulose can be chemically modified for producing derivatives used in different industries. Klemm et al. (2005) reported that “in the year 2003, 3.2 million tons of cellulose was used as a feedstock for the production of regenerated fibres and films and cellulose derivatives used in coatings, laminations, optical films and absorbents. Cellulose derivatives are also used as additives in building materials and also in pharmaceutical, food and cosmetic products”(helda.helsinki.fi). Table 3.7 presents the application of industrially important cellulose derivatives (http://polymerdatabase.com/polymer%20classes/ Cellulose%20type.html). Thickening solutions, gels, and fibers can be made from cellulose derivatives. CMC is used as a binder, thickener, stabilizer, suspending agent, or for controlling flow. CMC is used in food, toothpaste, shampoo, skin lotions, textiles, paper, adhesives, ceramics, detergents, and latex paints. CMC gels are used for separating molecules in the biotechnology area. HEC is soluble in water and is used in the oil industry. It is used as a thickener in drilling fluids and as a fluid-loss agent in cementing. Hydroxypropylcellulose shows extremely good surface and film-forming properties and is used for coating of paper. The hydroxyl groups in cellulose are reactive. “The cellulose derivatives are soluble in different types of solvents and can be processed into membranes, sponges, and fibers.

Table 3.7 Industrially important cellulose derivatives. Cellulose products

Application

Cellulose acetate Cellulose nitrate Cellulose xanthate Carboxymethyl cellulose

Coatings and membranes Membranes and explosives Textiles Water coatings, paints, adhesives, and pharmaceuticals Films, textiles, food, and tobacco industry Pharmaceutical industry Paints, coatings, films, and cosmetics

Methyl cellulose Ethyl cellulose Hydroxylethyl cellulose

Based on http://polymerdatabase.com/polymer%20classes/Cellulose%20type.html.

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Biobased Polymers

Cellulose membranes, show high permeability to toxic metabolic solutes. These have been examined as haemodialysis membranes (Baeyer et al., 1988). Further, cellulose shows good mechanical properties. The presence of hydroxyl groups make cellulose a good matrix for protein purification (Hou et al., 1991). Cellulose derivatives have been explored for biomedical applications. These are used in burns, wounds, various types of dermatological problems and as dressings in treating surgical incisions” (Nair and Laurencin, 2006). Cotton fiber is the most pure among the plant celluloses. It contains about 90% cellulose in contrast to wood, which contains about 50% cellulose. Chemically modified plant celluloses are utilized in various applications. Cellulose products are used in several industries such as wood and paper, fibers and clothes, personal care, and pharmaceutical industries (Belgacem and Gandini, 2011). The pharma industry accounted for the major market share of cellulose derivative in terms of value in 2014. The market is driven by the increase in demand for advanced drugs. Cellulose ether and derivatives are used as tablet binders and pharmaceutical excipients. The personal care and construction segment is expected to grow gradually during the next 5 years (www.grandviewresearch.com/industry-analysis/cellulosederivatives-market). The key players of the cellulose derivatives market are LOTTE Fine Chemical, Shin-Etsu Chemical Co., Ltd., Daicel Corporation, Samsung Fine Chemicals, Daicel Corporation., Ashland Inc., Akzo Nobel N.V. (performance additives), SE Tylose GmbH & Co. KG, CP Kelco, Shandong Head Europe BV, and Sichuan Nitrocell Co. Ltd. Cellulose has been extracted from green algae (Valonia, Halicystis, Cladophora) and brown alga (Laminaria) (Siddhanta et al., 2009). Algal cellulose has unique structural, hydrophilic, and mechanical properties (Fu et al., 2013). Some bacteriadGluconacetobacter, Sarcina, or Agrobacteriumdproduce cellulose, which is termed as bacterial cellulose (Brown, 1996; Carreira et al., 2011). Most cellulose-producing bacteria (Acetobacter) extrude cellulose in the form of ribbon from a single fixed site on the cell surface (U.S. Congress, 1993). A network of interlocking fibers is formed. Bacterial cellulose is produced in fermenter under agitation. Growth medium contains a carbon source, nitrogen source, salts, iron chelators, and additives for increasing production. Bacterial cellulose has been produced in commercial fermenters; yields are higher than 0.2 g of cellulose per gram of glucose. After fermentation, the bacterial cells are killed by sodium hydroxide treatment. Bacterial cellulose is not soluble in water and has a large surface area. The surface area of these fibers is around 200 times higher in comparison to the surface area of fibers from wood pulp. This, along with their ability to form hydrogen bonds, accounts for their unique interactions with water. Bacterial cellulose is able to absorb up to six times its weight of water. They show pseudoplastic thickening properties when used as suspensions. Sheets produced from bacterial cellulose show good mechanical properties. Tremendous progress has been made in

Properties of biobased packaging material

the area of bacterial cellulose production in the last decade. Weyerhaeuser in the United States and Ajinomoto in Japan are producing bacterial cellulose. Weyerhaeuser Company has developed Cellulon bacterial cellulose fiber. The unique reticulated network of fine fibers imparts thickening, binding, and coating properties. The diameter of fibers is typically 0.1 microns, whereas the diameter is 25e35 microns in case of some wood pulp fibers. Bacterial cellulose has a large surface area and can absorb liquids. So, a lower amount of bacterial cellulose can be used for producing binding, thickening, and coating agents. It has excellent thickness properties, so several applications in the food industry are possible. Paper coated with bacterial cellulose is very smooth and protects the fibers lying underneath from moisture. Applications in oil and gas recovery, mining, paints, adhesives, and cosmetics are also visualized. Sony Corporation is using this material in the production of high-end audio speaker systems due to its extremely good acoustic properties. In the last 2 decades several patents on bacterial cellulose have been obtained. The cost of bacterial cellulose ranges from $35 to $50 per pound. If the material is to be used in commodities, production costs will have to be reduced. Japanese researchers are making serious efforts to reduce the manufacturing costs.

3.1.3 Chitin and chitosan Chitin and chitosan are valuable biobased polymers and are abundantly available natural amino polysaccharides (Gabor and Tita, 2012). They have several of the structural and chemical characteristics of cellulose (Fig. 3.4). Both chitin and chitosan show high strength, biodegradability, and nontoxicity. Chitin is widely distributed in nature. Chemically, chitin contains repeating units of 1,4-linked 2-deoxy-2-acetoamido-a-D-glucose. Chitosan belongs to a family of partially N-acetylated 2-deoxy-2-amino-a-glucan polymers derived from chitin (Muzzarelli et al., 2012; Pillai et al., 2009; Sergeev et al., 2012; Fernandez-Saiz et al., 2010; Rinaudo, 2006). Chitin is a structural component of the exoskeleton of several organisms, for instance, insects and shellfish. It is also found in the cell walls of many plankton and other small organisms found in the ocean. Chitin is a versatile natural polymer due to the different biological needs of these species. Chitosan consists of linear beta-1,4-linked GlcN and GlcNAc units and is hydrophobic (Fajardo et al., 2010; Prashanth and Tharanathan, 2007). It is obtained from wastes from the shellfish industry and also from the chitin component of fungal cell walls. It can also be obtained from the yeast Saccharomyces cerevisiae (Fernandez-Saiz et al., 2010; Merzendorfer, 2011). Mucor rouxii contains chitosan in large quantities (Muzzarelli et al., 2012). Chitin is a highly insoluble material. It can be solubilized in various solvents such as hexafluoroisopropanol, chloroalcohols, hexafluoroacetone in combination with mineral

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Biobased Polymers

Figure 3.4 Structure of chitin and chitosan.

acids, and dimethylacetamide containing 5% lithium chloride (Ravi Kumar, 1999; Dutta et al., 2007). Chitin is a nitrogenous polysaccharide. It is hard and inelastic. Chitins are of three types: alpha, beta, and gamma chitins. Alpha chitin consists of antiparallel chains, whereas in contrast beta chitin has intrahydrogen-bonding sheets by parallel chains. As a result, beta chitin has weaker intermolecular hydrogen bonding and therefore has a more open structure that can be chemically modified (Minke and Blackwell, 1978). Gama chitin has a parallel and antiparallel structure, which combines alpha chitin and beta chitin ( Jang et al., 2004). Chitosan is more useful than chitin and is soluble in most of the organic solvents. Chitin and chitosan are highly basic polysaccharides, whereas most of the polysaccharides are acidic or neutral in nature. It is an all-around material in different areas (Ravi Kumar, 2000). Their unique properties are listed below: • Ability to form films • Polyoxy salt formation • Chelation of metal ions • Optical structural characteristics • Ability to form gel Extensive work on the chemical modification of chitin and chitosan has been done. Several derivatives having better properties have been produced (G€allstedt et al., 2005; Kjellgren and Engstr€ om, 2006; Kjellgren et al., 2006). Chitosan can be converted into different forms. One form is chitosan nanoparticles having size in the range of 200e1000 nm. Different methods such as preparation of multiple emulsion/solvent evaporation, ionic gelation methods, and freeze-drying have been used for the

Properties of biobased packaging material

preparation of chitosan nanoparticles. Ionic gelation method is an excellent method for chitosan. Chitosan shows good film-forming properties. The principal source of chitin is shellfish waste. Genetically engineered microbes can be also used for providing a stable supply of high-quality chitin compounds. The chitin polymers are being used in agriculture, medicine, manufacturing, and waste treatment. Chitin and chitosan are produced from crab, shrimp, and prawn wastes by chemical extraction process (Roberts, 1997). This is based on deproteination by alkali followed by deacetylation and demineralization by acid into chitosan. This process is aggressive (Roberts, 1997). Chitins are produced by fermentation or by using enzymes, but these processes are not economically viable (Win and Stevens, 2001). Few commercial plants located in the United States, Canada, Asia, and Scandinavia are producing chitin and chitosan (Ravi Kumar 2000). Chitosan shows many fascinating properties such as chemical inertness, biocompatibility, high-mechanical strength, good formation of film, and reduced cost (Marguerite, 2006; Virginia et al., 2011; Liu et al., 2012). Chitosan is used in a wide range of products and applications. Different properties of chitosan are needed for each application. These properties changes with the degree of acetylation and molecular weight. Chitosan is compatible with biologically active components that are included in cosmetic products (Ravi Kumar 2000). Chitosan shows reduced toxicity, good biocompatibility, and bioactivity. Therefore, it is being used in diverse applications such as biomaterials and pharmaceutical ingredients (Bae and Moo-Moo, 2010; Ramya et al., 2012). Chitosan is used in shampoos, rinses, and hair-coloring agents and is also used in the personal care industry. It also functions as a skin moisturizer. Due to its lower cost, it can compete with hyaluronic acid for this application (Bansal et al., 2011; Valerie and Vinod, 1998; Hafdani and Sadeghinia, 2011; Brine et al., 1991). Chitosan has been used for the production of edible coating. It produces materials having very high gas barrier properties (Krochta and Mulder-Johnston, 1997). Moreover, chitosan is used as coatings for other biobased polymers lacking gas barrier properties. But, care should be taken for moist conditions as in the case of polysaccharide-based polymers. The cationic properties of chitosan allows taking advantage of electron interactions with many compounds during processing and including specific properties into the material. The cationic property can be also used for incorporation and or slow release of active components. This would allow the manufacturer to tailor the properties (Hoagland and Parris, 1996). Chitin and chitosan show antimicrobial properties and have the ability to absorb heavy metal ions (Dawson et al., 1998; Chandra and Rustgi, 1998). These properties could be important in relation to the microbial shelf life and safety of the food product and to reduce oxidation processes in the food. The main interest in chitosan as a packaging material has been in edible coatings. Biodegradable laminate consisting of chitosan-cellulose and polycaprolactone can be used in modified atmosphere packaging of fresh produce (Makino and Hirata, 1997).

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Chitosan loses its positive charge at pH values higher than 6.5 and becomes insoluble in aqueous solutions. This limits its application in food or pharmaceutical products at neutral pH. Chitosan has several applications in food and nutrition due to its high nutritional quality. Chitosan is used in different areas such as biotechnology, material science and other fields. Chitosan shows antimicrobial properties against different microorganisms. (Di Pierro et al., 2011; Talens et al., 2012; Li et al., 2010; Fernandez-Saiz et al., 2008; Di Pierro et al., 2011; saiapm.ulbsibiu.ro).

Chitosan films have sufficient water vapor permeability and are used to increase the storage life of fresh products having higher water activity. The extremely good oxygen barrier properties of chitosan are because of its high crystallinity and the hydrogen bonds between the molecular chains (Kittur et al., 1998; G€allstedt 2001). Furthermore, chitosan shows good grease barrier properties (Kittur et al., 1998). Because of the presence of positive charge on the amino group, chitosan binds to lipids and fats (Jumaa and M€ uller 1999; Shu et al., 2001). These properties make it a good candidate for the barrier coating of cellulose products for food packaging. Chitosan has been applied in papermaking in the wet end and for surface sizing (Laleg and Pikulik, 1991). The mechanical properties of paperboard were improved when chitosan was used in the wet end. The retention of chitosan was good, because of the different charges of the chitosan and cellulose. For increasing the gas barrier properties, water insoluble sheets of chitosan and pulp fiber were developed (Hosokawa et al., 1991; G€allstedt, 2001; G€allstedt et al., 2005, 2006). Paper surface becomes smoother with the addition of chitosan so the printability of paper increases (Thomson, 1985). Chitosan coatings on paper, board, and cellophane have been studied (Domszy et al., 1985; Dobb et al., 1998; Krasavtsev et al., 2002; Ho et al., 2003; Vartiainen et al., 2004; Kjellgren et al., 2006; Bordenave et al., 2007). Chitosan is an interesting coating material for paper. The microstructure of papers coated with chitosan have been studied using infra red (IR) and scanning electron microscopy (SEM) (Bordenave et al., 2007). Chitosan was found to penetrate intensely into the paper, embedding the cellulose fibers, instead of forming a layer on paper. The materials coated with chitosan showed good barrier to moisture, but for food applications, it was not enough.

3.1.4 Pullulan Pullulan (Fig. 3.5) is a straight-chain polysaccharide containing alpha-1,6-linked maltotriose residues (Leduy et al., 1988). It is an exopolysaccharide produced by yeast, particularly Aureobasidium pullulans (Gabor and Tita, 2012). It is produced outside the cell and is soluble in water. Pullulan is made up of monomers containing three glucose sugars joined together. Bauer made early observations on this exopolymer in 1938. This was given the name pullulan by Bender et al. in 1959 (Leather, 2003). Pullulan has a molecular weight ranging from thousands to 2,000,000 Da. This depends on the growth conditions of the yeast. Pullulan

Properties of biobased packaging material

Figure 3.5 Structure of pullulan.

is not permeable to oxygen, nonreducing, and is not hygroscopic. Pullulan can be solubilized in water and produces clear and viscous solution. It shows film-forming and high-adhesion capabilities. Pullulans show high resistance to heat, and a wide range of elasticities and solubilities, and are biodegradable in biologically active environments. This allows them to be used in several ways. Pullulan is produced by fermentation using different types of raw materials (Bernier, 1958; Catley, 1971; Sena et al., 2006). Chemical modification of pullulan can be done for producing a polymer that is either less soluble or insoluble in water. The thermal and electrical properties of pullulans can also be changed. The remarkable properties of this polysaccharide are imparted by glycosidic linkage. By introducing the functional reactive groups, pullulan can be chemically modified for reducing the water solubility or developing sensitivity to pH, etc. Pullulan has several commercial applications. It is used as a flocculant, food additive, adhesive, substitute for blood plasma, and in films (Zajic and LeDuy, 1973; Singh et al., 2008; Cheng et al., 2011). Pullulan films can be developed into compression moldings. The films show antistatic and elastic properties and are thermally stable (Leather, 2003; U.S Congress, 1993). The main advantages of pullulan are: nonionic, nontoxic, nonimmunogenic, nonmutagenic, noncarcinogenic, and blood compatible. Its commercial production was started by Hayashibara Company in 1976. Hayashibara Biochemical Laboratories is selling different grades of pullulan: industrial grade ($6.50 per pound), food grade ($11 per pound), and medical grade ($15 per pound) (U. S Congress, 1993). Attempts are being made to increase the yield of pullulan with different strains of A. pullulans. Therefore, reduced production costs can be anticipated. Pullulan is tasteless and odorless. It provides bulk and texture and is used as a low-calorie food additive. Pullulan shows good oxygen barrier properties, good moisture retention, and antifungal properties. These properties make it a very good biopolymer for use in the food industry. Japan has been using pullulan

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Biobased Polymers

as a food ingredient and pharmaceutical bulking agent for a long time. According to the US Food and Drug Administration (FDA) the daily intake of pullulan is up to 10 g per day for a person based on food and usage. It is now being examined for its applications in medical fields such as tissue engineering, targeted drug and gene delivery, wound healing, and in diagnostic imaging using quantum dots. In drug delivery applications, hydrophobized pullulan is generally used as carriers. These molecules upon self-aggregation are able to form colloidally stable nanoparticles in water with monodispersity. Pullulan can entrap biological molecules. These molecules remain stable with higher shelf life. The degradation of pullulan in serum is faster in comparison to dextran. After incubation for 48 years, the degradation index is 0.7 in comparison with 0.05 for dextran. By using varying degrees of chemical modification, the degradation rate can be regulated. Pullulan can be formed into compression moldings that look like polystyrene or polyvinyl chloride (PVC) in gloss, transparency, hardness, strength, and toughness. However, it is much more elastic. At temperature higher than 200 C, it gets decomposed and does not produce toxic gases. In the food industry, a totally different application of pullulan can be found. It does not get broken by the digestive enzymes and so has no calorific content. It can be used in low-calorie foods and drinks, in place of starch. Pullulan also impedes fungal growth and can be used as a preservative. Pullulan is used as an edible film for food packaging. It is transparent, not permeable to oxygen, and resistant to oil and grease. Foods can be either coated by a polymer spray or immersed in a solution of pullulan. When the pullulan coating gets dried, an airtight membrane is formed, which can be used for the packaging of medicines and supplements and also food products (rich in oil) prone to oxidation. Removal of the pullulan coating before eating or cooking is not required. In the packaging of tobacco, pullulan increases the product durability and retains the smell. It also protects it from oxidative degradation and fungal attack. Waterinsoluble coatings can be produced by using the etherified or esterified pullulan. These have adhesive characteristics that resemble those of gum arabic. Adhesive characteristics and viscosity are dependent on the degree of polymerization. Pullulan can be modified and used as a paste that gelatinizes when it is moistened. Concentrated solutions of pullulan having high viscosity are used for producing fibers. These fibers have a gloss and resemble rayon. The tensile strength is comparable to that of nylon fibers. In conjunction with other materials, pullulan and its ester or ether derivatives can be used as binders for producing nonwoven fabrics. It can also be used to make writing and printing paper with or without the addition of other pulps. Pullulan can be used as a substitute for gum arabic in lithographic printing. Pullulan can be used as a binding agent for solid fertilizers; allows time-released fertilization and thereby avoids the burning of crops by controlling the release of nitrogen in the fertilizer. It can be used as a flocculating or aggregating agent for the precipitation of potash clays, uranium clays, and ferric hydroxide from slurries used in the beneficiation of mineral ores. Currently, synthetic chemicals are mainly used in mineral processing. As a binding agent in sand molds used for metal casting, pullulan prevents the generation of dust or toxic fumes. Pullulan can be used

Properties of biobased packaging material

as an additive in paints and resins, where its preservative and antioxidation properties help retain color and gloss. Also, illustrations printed on pullulan film with edible ink can be transferred onto food products. Pullulan acts as a plasma extender and does not have any undesired side effects in the medical area. It is completely excreted after metabolic turnover. Pullulan compounds also serve as drug carriers, and find application as medical adhesives. Although markets for different applications mentioned above are still relatively small, with some applications only in the preliminary stage, pullulan appears to have long-term commercial potential. (www.princeton.edu)

Molding articles can be produced from pullulan that resemble conventional polymers such as polystyrene in their transparency, toughness, and strength properties (Leathers, 2003). Pullulan is a very good material for food preservation (Conca and Yang, 1993). In biomedical applications, it is used in targeted drug and gene delivery, tissue engineering, wound healing, and even in diagnostic imaging medium. Other emerging areas for pullulan include oral care products and formulations of capsules for dietary supplements and pharmaceuticals, leading to increased demand for this biopolymer. (Rekha and Chrndra, 2007; Barkalow et al., 2002; Leathers, 2003; paperity.org).

3.1.5 Alginates Alginates (Fig. 3.6) are natural biopolymers extracted from brown seaweeds (Gabor and Tita, 2012). These are type of hydrocolloids and are found in abundance in marine brown algae and in Pseudomonas and Azotobacter genera of bacteria (Draget, 2000; Hay et al., 2013; Skjåk-Bræk and Draget, 2012; Tapia et al., 2008; De Lima et al., 2009; Draget et al., 1997). These extracellular polymeric substances are the main structural component of cell walls of algae and comprise up to 40e45% of the total algal dry matter (SkjåkBræk and Draget, 2012). Alginates contribute to highly structured biofilm-matrix and cyst-wall formations, in Pseudomonas and Azotobacter, respectively (Rehm, 2009). Alginates can be solubilized in cold water, forming thermostable gels, and are used in food (as stabilizers, viscosifiers, and gelling agents), cosmetics, beverage, paper, printing, and pharmaceutical industries (Helga and Svein, 1998; Hay et al., 2013).

Figure 3.6 Structure of alginate.

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Biobased Polymers

Major demand for alginate is in the area of food and beverage, paper and textile industries. In food and beverage industry, it plays a significant role as emulsifier, thickener, gelling agent, and stabilizer and is used for improving the texture of food recipes (Iain et al., 2009; Sriamornsak and Kennedy, 2008). It is used in jellies, ice cream, salads, alcoholic drinks, lactic drinks, etc. and in several other products. In paper and textile industry, it is used for printing and dying and for controlling the viscosity in processing of final product. Alginate is also used in pharmaceutical industry in tablets, liquid medicines and for making dental impression materials and as a gelling agent. Alginate containing wound dressings are commonly used, particularly in making hydrophilic gels over wounds producing comfortable, localized hydrophilic environments in curing wounds. Alginates are used for controlled drug delivery. The rate depends on the molecular weight and type of alginates used. Dental impressions made with alginates are easy to handle as they fast set at room temperature and are cost-effective too. Alginates are used in treatment of obesity; various functional alginates are being examined in human clinical trials. Alginates are used in manufacturing of ceramics to production of welding rods and water treatment. (paperity.org; www.progressbiomaterials.com; Peter et al., 2011; Mandel et al., 2000; Onsoyen, 1996; Alexnader et al., 2006; Goh et al., 2012; Onsoyen, 1996; Georg et al., 2012; Qin et al., 2007; Xie et al., 2001).

Globally, the demand for alginates was valued at USD 624 million in 2016, and the demand is projected to reach USD 923.8 million by 2025 with a consumption volume of 21,516 tons. (Grandview Research, 2017) Structurally, alginates are a family of linear, non-repeating block copolymers consisting of variable ratios of beta-D-mannuronic acid (M) and its C5 epimer a-L-guluronic acid (G) linked by beta- (1,4)-glycosidic bonds. Variation in the molar ratios of M to G residues controls the molecular weight and material properties of alginates. Because of their unique water retaining capability, biocompatibility, low toxicity, relatively low cost of production, and temperature independent mild gelation/sol-gel transition ability in the presence of multivalent cations such as calcium, alginates are excellent biomaterials for use in biomedical applications, including wound healing, dental implants, drug delivery systems, tissue engineering, and regenerative medicine. Alginate production is tightly regulated in bacteria thus efforts have been made to characterize and engineer the regulatory system in Pseudomonas fluorescens to identify the correlation between precursor availability and alginate production. (Rehm, 2010; Lee and Mooney, 2012; Lien et al., 2013; dspace.lboro.ac.uk).

Alginates are able to form film and are resistant to solvents, oil, and grease. Furthermore, alginates functions as a penetration controller when blended with pure starch. Alginates are used in sizing and coating of paper. A reduction in contact angle of water was observed when the paper was coated with alginate. This shows an increase in hydrophilicity of the surface, which becomes smoother and more homogeneous resulting in an increased affinity of the paperboards to water. Inclusion of sodium alginate in chitosan formulations significantly increased the fat barrier of coated papers and reduced the treatment cost. Indeed, the chitosan/alginate mixture, after coating on paper, showed fat resistance with a synergistic effect, taking into account the possible limitation of chitosan penetration into the paper and the contribution to a smoother surface due

Properties of biobased packaging material

to film-forming capacities of gums at low concentration. Tensile strength of paperboards was reduced with alginate coatings. This is mainly because of the swelling of cellulose fiber by solvent penetration during coating and may be partially because of the reason that alginate impregnated into the paper and interfered with fiber-to-fiber interaction. (saiapm.ulbsibiu.ro; Ham-Pichavant et al., 2005; Rhim et al., 2006).

Sodium alginate is [a] commonly used alginate in the industry. It consists of a-L-guluronic acid residues (G blocks) and beta-D-mannuronic acid residues (M blocks), and also segments of alternating guluronic and mannuronic acids. Although alginates are a heterogeneous family of polymers having different content of G and M blocks depending on the source of extraction, alginates having high G content are more important industrially. The acid or alkali treatments used to produce sodium alginate from brown seaweeds are simple. The difficulties in processing arise mostly from the separation of sodium alginate from slimy residues. Annual production of alginates is approximately 38,000 tons worldwide. (Black and Woodward 1954; Draget, 2000; Siddhesh and Edgar 2012; Helgerud et al., 2009; paperity.org).

3.1.6 Carrageenan Carrageenan (Fig. 3.7) is a polysaccharide having good gas barrier properties and is used as a natural additive in various food and pharmaceutical applications (Chan et al., 2013; Hamzah et al., 2013; Karbowiak et al., 2008; Martins et al., 2012; Kong and Ziegler, 2013; Larotonda, 2007; Abdul; Khalil et al., 2017; Gabor and Tita, 2012). Carrageenan is a water-soluble straight biopolymer. Many Rhodophyceae species contain polysaccharides that fill the gaps within the cellulose of the plant. These polysaccharides include carrageenan, agar, and furcellaran, which contain a backbone of galactose that differs in the location and also amount of ester sulfate groups and 3,6anhydrogalactose groups. The differences in composition and conformation produce different rheological properties, useful for different types of foods (Imeson, 2000). In Europe, carrageenan was used more than 600 years ago in Ireland. The name Carrageenan is the old name for Carrageenan. It was first used in 1862 for the extract from Chondrus crispus. Since then, Irish moss also has been used for textile sizing and for clarification of industrial beer. Its commercial production started in the United States in the 1930s. The trading shifted from dried seaweed meal to refined carrageenan. There was an increase in carrageenan production after World War II. Crude carrageenan extracts were fractionated in the early 1950s and different types of carrageenan were characterized. For identification of different carrageenans, a Greek prefix was introduced. The structure of carrageenans was determined in the same period. The structure of 3,6-anhydro-D-galactose in k-carrageenan, and also the type of linkages, between galactose and anhydrogalactose rings, were identified. Nowadays, the commercial production of carrageenan is not limited to production from Irish moss, and several red seaweeds are used. These seaweeds have traditionally been harvested from naturally occurring populations. Seaweed farming started more than 200 years ago in Japan.

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Figure 3.7 Structure of carrageenan.

Today several seaweeds are commercially grown, reducing the pressure on naturally occurring populations. A few large companies accounting for 80% of the supply are dominating the carrageenan market (van de Velde and de Ruiter, 2002). The major players in this industry are FMC BioPolymer, Marcel Carrageenan, and Seatech Carrageenan Company. Other major players present in the carrageenan market include ACCEL Carrageenan Corporation, Rico Carrageenan, Xieli, Global Ocean, LONGRUN. Greenfresh, Gather Great Ocean, Brilliant, TIC Gums, MCPI, TBK, Cargill, ISI, CP Kelco, CEAMSA, Karagen Indonesia, Danisco, CEAMSA, Shemberg, Gelymar, Quest International (the Netherlands), and CP Kelco (monotonecritic.com/2018/02/ 08/global-carrageenan-market-2017-shemberg-fmc-ceamsa-danisco-gelymar-karagenindonesia-cp-kelco-isi-cargill-tbk/). Different carrageenans show different rheological behavior, ranging from viscous thickener to thermally reversible gels. The texture of these gels ranges from soft and

Properties of biobased packaging material

elastic to firm and brittle. Kappa carrageenan interacts in a synergistic manner with other gums, for further modifying the gel texture. A specific interaction between kappa carrageenan and kappa casein is used for stabilizing dairy products (Imeson, 2000). Carrageenan is used as natural thickener, formulation stabilizer, or gelling agent in food industry and pharmaceuticals (van de Velde and De Ruiter, 2002). In the food industry, carrageenan is used in the dairy sector, in chocolate milk, cottage cheese, frozen desserts, and whipped cream. “These are also used in several types of non-dairy food products, like jellies, pet foods, sauces, instant products, and non-food products, like pharmaceutical formulations, cosmetics and oil well drilling fluid. Except starch, carrageenan with pectin, is the major natural gelling polysaccharide obtained from plants or seaweeds and used as functional ingredient in foods, cosmetics and pharmaceuticals” (repositorio-aberto.up.pt; Imeson, 2000; van de Velde and De Ruiter, 2002; De Ruiter and Rudolph, 1997). Based on the number of sulfates per disaccharide, there are three types of carrageenans: • Kappa carrageenan (one sulfate), • Iota carrageenan (two sulfates) • Lambda carrageenan (three sulfates) Kappa carrageenan acts as an emulsifier, stabilizer, and bodying agent in chocolate, ice cream, cheese, and puddings and is the most used carrageenan. It gives strong and brittle gels with water syneresis. Iota carrageenan is used for ready-to-eat meals. It forms thermoreversible soft gels. Lambda carrageenan is used for whipped cream. It is a highly sulfated galactan with viscosity-enhancing properties. The food grade carrageenan is often mentioned as E407 or E407a in processed food ingredients, which means it has processed seaweed. The carrageenan is mentioned as dietary fiber in a few products. Carrageenan possess a complex hybrid chemical structure containing l-, i-, or k-carrageenan monomers together with nongelling biological precursors monomers such as n- or m-carrageenan monomers. k-Carrageenan shows the highest tensile strength in comparison to land i-carrageenan films. The use of carrageenan as edible films and coatings already covers various fields of the food industry. Examples are application on fresh and frozen meat, poultry and fish for preventing superficial dehydration, ham or sausage-casings, granulation-coated powders, dry solid foods, oily etc., but also manufacturing soft capsules and particularly nongelatin capsules. Indeed, this protective barrier can also be used in food for preventing the transfer of moisture, gases, flavours, or lipids and thus to maintain or improve food quality and to increase the shelf life of the food products. Another emerging technology that has been applied to various biopolymers, include carrageenan-based coating, is their use as antimicrobial agent carriers in active packaging systems. (repositorio-aberto.up.pt; Ninomiya et al., 1997; Tanner et al., 2002; Bartkowiak and Hunkeler, 2001; Fonkwe et al., 2006; Krochta and De Mulder-Johnston, 1997; Shaw et al., 1980; Macquarrie et al., 2004; Lahaye, 2001 Cha et al., 2002; Hong et al., 2005; Choi et al., 2005).

In 2016, the global carrageenan market was 762.35 million US dollars. It has around 13.3% share of the global food and beverage hydrocolloids market. World carrageenan

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Biobased Polymers

production was more than 56,000 tons in 2013. The market is competitive in North America, Chile, Argentina, Denmark, France, Japan, Mexico, Morocco, Portugal, North Korea, South Korea, Spain, and Russia (www.mordorintelligence.com/industry.../ global-carrageenan-market-industry). The Philippines is the largest producer of carrageenan accounting for about 77% of the world’s supply. As compared to North America and Europe, the Asia-Pacific market for carrageenan is extremely huge. China is the major exporter of carrageenan to both the United States and Europe. In the United States, carrageenan is used in chocolate milk. Carrageenan is a regulated food additive. There are concerns over the maximum quantity (in mg) of carrageenan that can be used in food. The major driver of the carrageenan market is the increasing demand for processed foods. Within the processed food ingredients, the increasing demand for organic ingredients is driving the market for carrageenan. Other factors for the market growth are several functional and health benefits of the product.

3.1.7 Xanthan Xanthan gum is an important industrial biopolymer (Garcia-Ochoa et al., 2000; Trilsbach et al., 1984; Kang and Pettit, 1993; Flores Candia and Deckwer, 1999; Gabor and Tita, 2012). It is produced by fermentation on a commercial scale and was iscovered at the NRRL laboratory of the United States Department of Agriculture (USDA) in the 1950s (Margaritis and Zajic, 1978). The xanthan gum produced by Xanthomonas campestris NRRL B-1459 was studied widely. Its properties allow it to be added to other types of natural and synthetic water-soluble gums. During the 1960s, research was conducted in several laboratories, resulting in semicommercial production. Commercial production started in 1964. The xanthan polymer contains five different sugar groups. The primary structure consists of repeated pentasaccharide units formed by two glucose, two mannose, and one glucuronic acid units. The molar ratio is 2.8:2.0:2.0 (Fig. 3.8). The chemical structure of the main chain is similar to that of cellulose. About one-half of the terminal D-mannose contains a pyruvic acid residue which is linked to the 4 and 6 positions via keto group, with an unknown distribution. D-Mannose unit linked to the main chain contains an acetyl group at position O-6. The presence of acetic acid and pyruvic acid produces an anionic type of polysaccharide. The composition of the various polysaccharides produced by Xanthomonas has been reported by Kennedy and Bradshaw (1984). The trisaccharide branches are closely aligned with the polymer backbone. The resulting stiff chain may exist as a single, double, or triple helix which interacts with other polymer molecules to form a complex. The molecular weight distribution ranges from 2  106 to 20  106 Da. It depends on the association between chains,

Properties of biobased packaging material

Figure 3.8 Structure of xanthan gum. (In Xanthan 1,4-linked beta-d-glucose residues having a trisaccharide side chain attached to O-3 of alternate d-glucosyl residues are present. The side chains are (3/1)a-linked d-mannopyranose, (4/1)-beta-d- mannopyranose and (2/1)-beta-d-glucuronic acid. These side chains account for the anionic properties of xanthan gum. (Gabor and Tita, 2012).)

forming aggregates of several individual chains. The molecular weight of xanthan is affected by varying the fermentation conditions. (Sandford and Baird, 1983; Kennedy and Bradshaw, 1984; Morris, 1977; Milas and Rinaudo, 1979; www.wiley-vch.de).

The toxicological properties of xanthan gum have been studied. It is not toxic and is not able to impede the growth. It is nonsensitizing and does not cause any skin or eye irritation. The FDA has approved xanthan for use as a food additive without any quantity limitations (Kennedy and Bradshaw, 1984). In 1980, the European Economic Community added xanthan to the food emulsifier/stabilizer list as item E-415. Xanthomonas campestris is one of the first bacterial polysaccharide production systems targeted for genetic engineering. By the use of recombinant DNA technology, genetic modification of Xanthomonas under certain conditions has increased the xanthan production rate by more than 50%. This technology would enable to create new xanthan biosynthetic pathways in host organisms in the future. Xanthan gum is an important microbial hydrocolloid used in the food industry as a thickening agent and stabilizer (Flore et al., 2010). It is produced by fermentation of X. campestris in an aerobic process (Laneuville et al., 2012). Several different substrates such as molasses and corn syrup are used. Xanthan gum is extruded from the bacteria during the polymerization process. It is recovered by precipitation with alcohol followed by removal of the bacterial cells. The crude broth is used directly following sterilization for certain applications like enhanced oil recovery. The fermentation medium becomes viscous during the production of xanthan. This increases the energy needed for the mixing process providing oxygen to the bacterial cells.

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Biobased Polymers

Xanthan gum has different uses. “It is used in mineral ore processing (used as a biocide), oil recovery (provides viscosity control in drilling mud fluids), paper manufacturing (used as a modifier), agriculture (acts as plant growth stimulator), pharmaceuticals (being evaluated for sustained drug release), and cosmetics (controls dust release). Xanthan gum is used for enhanced oil recovery as a mobility control agent, in drilling operations to increase the suspension capacity of the drilling mud and in gels to improve the volumetric sweep efficiency”(www.princeton.edu). Xanthan gum has been used as gelling agent in desserts, ice creams, puddings, and cheese spreads. Also, it has been used in the clear-gel toothpastes. Reading the labels on many of the processed foods in the supermarket gives one a clear picture of the wide use of this material. Many of the fat-free foods and packet soups are becoming available. In terms of production volume, xanthan gum is the most widely used microbial polysaccharide. Merck and ADM companies have expanded their xanthan production facilities. Approximately 60% of the xanthan is used in foods, and the remaining is used for applications in industry. The cost of food-grade xanthan is about $8 to $10 per pound, whereas the cost of nonfood grades is about $5 per pound. Only small quantities of genetically modified xanthan are available. Xanthan gum is nongelling and used for controlling viscosity because of the insubstantial associations providing it with weak-gel shear-thinning properties. It hydrates readily in cold water without the formation of lumps and gives a reliable viscosity, for use as thickener, stabilizer, emulsifier, and foaming agent. The ability to consistently hold water can be used to control the syneresis and to slow recrystallization of ice in freeze-thaw situations. The strength of xanthan gel improves on freeze-thaw. It possesses very high low-shear viscosity and has a strong shear-thinning property. This means that it can be mixed easily, poured, and swallowed. Its high viscosity at low shear provides good suspension and coating properties and imparts stability to colloidal suspensions. It is not much affected by temperature, pH, ionic strength, or shear. So, it is suitable for use in salad dressings. The structural properties of xanthan can be adjusted by ionic strength and the temperature. Xanthan chains are coiled under low-ionic strength at high temperature, whereas xanthan chains are arranged in helical conformation under high-ionic strength or low temperature. High molecular weight of xanthan favors the building up of physical and chemical networks that are used as carriers for drugs and proteins and as scaffolds for cells. Due to its acid resistance property, xanthan is used as excipient in tablets or as supporting hydrogels for drug release when combined with other polymers.

3.1.8 Dextrans Dextran is a complex branched polysaccharide (Fig. 3.9) and is a neutral polymer. These polymers are homopolysaccharides consisting of D-glucose containing chains of varying length from 10 to 150 kDa (Bhavani and Nisha, 2010; Sarwat et al., 2008; Gopal

Properties of biobased packaging material

Figure 3.9 General structure of class 1 dextrans consisting of a linear backbone of a(1/6)-linked Dglucopyranosyl repeating units. (Reproduced with permission from https://www.dextran.com/aboutdextran/dextran-chemistry/dextran-structure.)

Rao et al., 2014). Dextrans are produced by dextransucrase enzyme. This extracellular enzyme is liberated from lactic acid bacteria belonging to the genera, viz., Leuconostoc, Lactobacillus, Pedi coccus, Streptococcus, and Weissella. Louis Pasteur discovered dextran as a bacterial product in wine, but large-scale production became possible after the development of a process using bacteria by Allene Jeanes. Dextran is now produced from sucrose by using lactic acid bacteria. Hucker and Pederson (1930) were the first to report the production of dextran from sucrose by Leuconostoc species. Later on, the production of dextran from different bacterial strains was reported by Jeans et al. (1954). Both soluble and insoluble types of dextran are produced and the molecular weights range from 1.5  104 to 2  107 and higher. Dextrans consist of D-glucopyranose units having mainly alpha-(1/6) linkage in the main chain and a variable amount of alpha-(1/2), alpha-(1/3), alpha-(1/4) linkages, which are branched (Jeanes, 1966; Sidebotham, 1974; Monsan et al., 2001; Be Miller, 2003). “Dextrans from L. mesenteroides NRRL B1299 and L. mesenteroides NRRL B512F are well characterized and classified. Dextran from L. mesenteroides B512F contains 95 percent of alpha-(1/6) linkages and 5 percent of alpha-(1/3)

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branch linkages; whereas insoluble dextran from L. mesenteroides 1299 contains 63 percent alpha-(1/6), 27 percent of alpha-(1/2) and 8 percent of alpha-(1/3) linkages”(Dols et al., 1997). On an industrial scale, dextran is produced from sucrose by fermentation. These are produced in substantial quantities by Leuconostoc mesenteroides. The product yield is dependent upon several factors like temperature, pH, and nitrogen source. Laboratory workers are familiar with bacterial dextrans. Cross-linked dextran beads are used in gel filtration columns. Dextran is available commercially and used in food, chemical, and pharmaceutical industries (Alsop, 1983; Sutherland, 1996). Dextrans of different molecular weights are produced by several microorganisms. The structures vary from slightly to highly branched. Commercially dextran is produced by using Leuconostoc mesenteroides NRRL B-512 which is a nonpathogenic organism The basic reaction catalyzed by dextransucrase is n sucrose / (a-D-glucopyranosyl unit)n þ n D-fructose. Branches arise from position O-3 of the glucosyl units. In commercial dextran, the degree of branching is about 5 percent. About 40 percent of the side chains are single a-D-glucopyranosyl units; about 45 percent are two units long, and about 15 percent contain more than 2 units. The average molecular weight of native commercial dextran from Leuconostoc mesenteroides NRRL B-512 is found to range from 9 to 500 million. Dextran produces low-viscosity solutions which distinguishes it from other high-molecular-weight polysaccharides. (www.aaccnet.org)

Dextrans having lower molecular weight are found suitable for clinical applications. There is a huge scope to use low-molecular weight dextrans in medical applications, especially in drug delivery systems and surgery. But, low-molecular-weight dextrans sell for about $80 per pound. Novel and higher-volume applications for these materials are being developed. Dextran is a neutral polymer. These are produced from sucrose, which is a product of sugarcane industries and sugar beet. Dextran is produced by fermentation or by enzymatic filtration method. The latter method is preferred because it produces high dextran yield and the product quality is uniform, which allows the product to be readily purified. These methods allow the adjustment of system conditions for controlling the molecular weight of the products. This is a necessary requirement for polysaccharide biosynthesis. The solubility of dextran in water is high and the solutions behave as Newtonian fluids. The viscosity of solution depends on several factors such as concentration, temperature, and molecular weight, which show a characteristic dispersal. The hydroxyl groups in dextran present several sites for derivatization, and these functionalized glycol conjugates represent an unexplored class of biocompatible and environmentally safe compounds (www.millioninsights.com i Chemicals & Materials). Nowadays, the trend is toward eating healthy and additive-free food. This has made dextran from food grade lactic acid bacteria an attractive solution. In food applications, dextrans are known for their emulsifying, viscosifying, texturizing, and stabilizing properties (www.millioninsights.com i Chemicals & Materials).

Properties of biobased packaging material

Dextran can be used as a novel component swapping the commercial hydrocolloids in bakery and other food applications. Prebiotic oligosaccharides are produced by hydrolysis of dextran. It is a new area attracting research and industrial attention. Dextrans have many applications in medical fields. “Dextrans have been used as blood volume expanders, to improve blood flow in capillaries for the treatment of vascular occlusion, in surgical sutures for wound coverings and in the treatment of iron deficiency anemia in both humans and animals. Dextran-hemoglobin compounds can also function as plasma expanders and can be used as blood substitutes that have oxygen delivery potential (U.S. Congress, 1993). Dextrans modified chemically, such as dextran sulfate, show both anticoagulant and antiulcer properties. Other modified dextrans such as Sephadex have been used extensively in the separation of biological compounds. Industrial applications include the use of dextrans into x-ray and other photographic emulsions. This results in the more economical utilization of silver compounds and also reduces surface gloss on photographic positives. Dextrans also find application in the drilling of oil muds for improving the ease and efficiency of oil recovery; in agriculture as seed dressings or soil conditioners. The protective polysaccharide coatings improve germination under suboptimal conditions. Several applications have been proposed for dextrans but only a small number of these have been developed on a large scale” (www.princeton.edu; U.S. Congress, 1993).

3.1.9 Pectin Pectin (Fig. 3.10) is the most complex polysaccharide in plant cell walls. Pectin is a family of galacturonic aciderich polysaccharides and is an anionic biopolymer. Pectin functions in plant growth, plant defense, morphology, and development. It is also used as a gelling and stabilizing polymer in food and specialty products and has several biomedical uses and positive effects on human health (U.S Congress Publications, 1993; Voragen and Pilnik, 1995; Thibault and Ralet, 2001; Sharma et al., 2006). Pectin is soluble in water (Gabor and Tita, 2012). It consists of chains of linear regions of (1/4)-a-D-galacturonosyl units and their methyl esters, interrupted in places by (1/2)- a- L-rhamno- pyranosyl units (De Medeiros et al., 2012). Three pectic polysaccharides, have been isolated from primary plant cell walls. These are homogalacturonan (HG), rhamnogalacturonan-I (RGI-1) and substituted galacturonans, rhamnogalacturonans II (RGIIs), and xylogalacturonans (XGs). HG is a linear chain of 1,4-linked a-D-galactosyluronic residues, in which some of the carboxyl groups are methyl esterified. They may also be O-acetylated at the C-2 and C-3 positions. Homogalacturonans have been isolated from apple pectin and sunflower heads and were obtained by extraction to break covalent bonds so they may have been released from a heterogeneous pectic polysaccharide. Pectin has rhamnopyranosyl residues inserted in the galactosyluronic backbone at 1 to 4 percent substitution. The other main feature of these rhamnogalacturonan-I (RG-I) chains are large substituted side chains.

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Figure 3.10 (A) A repeating segment of pectin molecule and functional groups: (B) carboxyl; (C) ester; (D) amide in pectin chain.

Depending on plant source and method of isolation, between 20 and 80 percent of the rhamnopyranosyl residues are substituted at C-4 with neutral and acidic oligosaccharide side chains. The major side chains contain large linear and branched a-L-arabinofuranosyl and/or beta-D-galactopyranosyl residues and their relative proportion and chain lengths may differ depending on plant source. Other rarer side chains are also present. (shorterijrrpas.com)

Pectins are finding application in food and beverage industries (Mesbahi et al., 2005; Sriamornsak and Kennedy, 2008). These are mostly used as gelling agents, but can be also used as thickener, water binder, texturizer, emulsifier, and colloidal stabilizer. Christiaens et al. (2016) studied enzymatic and nonenzymatic pectin conversions during food processing and processestructureefunction relations. Because of its structural complexity, food processing of pectins can result in complex and somewhat unpredictable effects on texture, viscosity, and gel formation. An excellent review on advances in pectin production, its role as a nutraceutical, and its possible prebiotic potential has been published (Naqash et al., 2017). Low-methoxyl-content pectins form thermoreversible gels in the presence of calcium ions and at low pH, while in contrast, high-methoxyl-content pectins quickly form thermally irreversible gels in the presence of sufficient sugars and at low pH; the lower the methoxyl content, the slower the set. The extent of esterification may be reduced using commercial pectin methylesterase, which results in a higher viscosity and stronger gelling in the presence of calcium ions. Highly acetylated pectin (2-Oand/or 3-O-galacturonic acid backbone) from sugar beet is found to gel poorly but has substantial ability to emulsify because of its more hydrophobic nature, but this could

Properties of biobased packaging material

be due to protein impurities (Dickinson, 2003). Pectin is protective toward milk casein colloids, improving the properties such as solubility, foam stability, gelation, and emulsification of whey proteins while using them as a source of calcium. Pectin also shows some health benefits. Pectin can be used as an anticancer agent. They are able to bind and impede the various actions of the prometastatic protein galectin-3 (Maxwell et al., 2012).

3.1.10 Glucans Beta-glucans (Fig. 3.11) are polysaccharides of glucose. These are found naturally and are present in the cell wall of several living organisms such as bacteria, fungi, yeasts, algae, lichens, and plants (Zhu et al., 2016; Zekovic et al., 2005; Rieder and Samuelsen 2012; Ahmad et al. (2012). Other names for beta-glucans include: • Beta-glycans • Beta-1,3-glucan • Beta-1,3/1,6-glycan Beta-glucan is a soluble fiber. It is obtained from the cell walls of algae, bacteria, fungi, yeast, and plants. Beta-glucan found in yeast and mushrooms contains 1,3-glucan linkages and sometimes 1,6 linkages. On the other hand, beta-glucans from grains contain 1,3 and 1,4 linkages (1; 2). Beta-1,3/1,6 glucan derived from yeast shows higher biological activity in comparison to the 1,3/1,4 counterparts. Beta-glucans are found in several species, such as, Lentinus edodes, Rhynchelytrum repens, Grifola frondosa, Tremella aurantia, Tremella mesenterica, Zea may, Agaricus blazei, Phellinus baummi, Saccharomyces cerevisiae, and Agaricus blazei murell (mushroom). Beta-glucans are used as texturing agents in the food industry. These are considered as GRAS. The intake of beta-glucans is related to the reduction of plasma cholesterol and stimulation of the immune system, depending on the beta-glucan nature. Beta-glucans are being used for developing bio-based films for food contact materials and medical applications. In the recent years, interest is being shown in the development and use of bio-based films and packaging materials. Applications of beta-glucan related to films developments are described by using isolated betaglucan or in combination with other biopolymers. Yeast cell wall, consisting of beta-1,3-glucan network cross linked to beta-1,6-glucan, mannoprotein, and a small amount of chitin, are good matrix for encapsulation and for preparations of film. Dispersions of beta-glucan from oat cultivars were found to be promising films forming hydrogels, with potential to be used as biodegradable edible packaging film. (www.aaccnet.org; Rahar et al., 2011; Peltzer et al., 2017).

Figure 3.11 Structure of b-glucan.

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The term glucan is generally used to describe the glucan component of the yeast cell wall. These polymers are present in abundance in yeast and make up about 12%e14% of the total dry cell weight. Baker’s yeast, Saccharomyces cerevisiae, is a common source for this glucan. It is also found in bacteria, fungi, lichen, and higher plants. Large quantities of yeast are generated from the baking and the brewing industries. The purification of glucan from yeast cells is done by using hot alkali for removing all other cellular materials, allowing recovery of the insoluble glucan. Yeast glucan contains both high and lower molecular weight polymers.

3.1.11 Gellan Gellan is a complex polysaccharide (Fig. 3.12). It is a straight anionic heteropolysaccharide containing a tetrasaccharide repeating unit consisting of rhamnose, D-glucose, and D-glucuronic acid. The ratio is 1:2:1 (Gabor and Tita, 2012). Gellan gum earned FDA approval for food applications in September 1990 (Moscovici, 2015) and shows the potential to replace existing gelling agents (Chaudhary et al., 2013). Gellan is produced by Pseudomonas elodea, which is a bacterium obtained from plant tissue (Rojas-Gra€ u et al., 2008). Gellan is produced by the same fermentation process described for xanthan. The properties of gellan can be modified easily. Treatment with hot caustic soda produces a polymer having the desirable properties of low viscosity at high temperature. Strong gels can be produced by cooling gellan in the presence of several cations. Gellan gum is the newest member of the microbial polysaccharides developed commercially. It has been developed by the Kelco Division of Merck under the trade names Kelcogel and Gelrite. GelIan is currently selling for about $5 per pound. It is available in two formsdhigh- and low-acyl content. The high-acyl-content version forms high-elastic, soft, and nonbrittle gels. The low-acyl gellan gum products form brittle, firm, and nonelastic gels. Changing the ratio of these two forms allows the

Figure 3.12 Structure of gellan.

Properties of biobased packaging material

production of a variety of textures and formulations based on the demand for the product in the industry. Gellan gum enables suspension and uniform dispersion of insoluble particulates in protein-fortified beverages and nut milks. The producers are increasing their production volumes for catering to rising market demand (https://www.grandviewresearch.com/ industry-analysis/gellan-gum-market). Gellan is used in food, cosmetic, personal care, industrial cleaning, and pharmaceutical industries. Growing demand for the product as oil content stabilizer in personal care items including face lotions, creams, face washes and masks is expected to push industry growth. The product will gain significant growth in food and beverage industries as a thickening agent, stabilizer, emulsifier and as a gelling agent in frostings, glazes, icings, jams, and jellies. This product can be used as an individual component in food and beverage systems or in combination with other stabilizers for producing a range of food products. The product shows better properties such as low viscosity, high tolerance to pH, transparent appearance, superior flavor release and shearing abilities. These properties will drive its application in food and beverage, pharmaceutical, and cosmetics. The product also assists in separation of ingredients during preparation of bakery goods and also helps to regulate the consistency of gel and prevents the colour change in spreads and purees. It helps to increase fluid viscosity allowing production of thick liquids which can be used as marinades or toppings in meat products. (repositorio-aberto.up.pt)

3.1.12 Collagen Collagen is one of the most useful biomaterials (Maeda et al., 1999). It is a group of naturally occurring proteins and is found only in animals and is the major component of connective tissue (Brodsky and Persikov, 2005; Gelse et al., 2003; Ortega and Werb, 2002; Kadler et al., 2007; Myllyharju and Kivirikko, 2001, 2004; Gabor and Tita, 2012). This protein is found in abundance in mammals and makes up about 25%e35% of the whole body protein content. Collagen, in the form of elongated fibrils, is mainly found in tendon, ligament, and skin. In the connective tissue there are more than 20 types of collagen. It contains different polypeptides, mainly glycine, proline, hydroxyproline, and lysine. Some differences in amino acid composition are seen across collagens obtained from various sources (Karim and Bhat, 2009; Vroman and Tighzert, 2009). There are a minimum 27 types of collagens, and the structures all serve the same purpose, that is, to help tissues to withstand stretching. Collagens are present in pig skin, pork, cattle bones, and bovine hide. But for commercial application, collagen is obtained from nonmammalian species (GomezGuille et al., 2011). Gelatin is produced by the hydrolysis of collagen. The extent of conversion of collagen into gelatin depends on several factors such as pretreatment method, function of pH, temperature, and extraction time ( Johnston-Banks, 1990).

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Collagen films are mainly used in ophthalmology as drug delivery systems for slowly releasing incorporated drugs (Rubin et al., 1973). Also, it has been used for tissue engineering of skin replacement, bone substitutes, and artificial blood vessels and valves (Lee et al., 2001). On the basis of their structure and supramolecular organization, collagens are grouped into the following (Gelse et al., 2003): • Fibril-forming collagens • Fibril-associated collagens • Network-forming collagens • Anchoring fibrils • Transmembrane collagens • Basement membrane collagens with unique functions Collagen has several functions, including cell adhesion, cell migration, angiogenesis, tissue morphogenesis, tissue repair, and tissue scaffolding. Collagen is hydrophilic, shows insignificant cytotoxicity, good hemostatic properties, and is biocompatible and readily available (Stylianou et al., 2010). Most of the biological reactions occur on surfaces or interfaces. So, it is of great importance to nanostructure the collagen thin film. These films are useful for solving several biological problems, including cell morphology and the effect of surface properties on intracellular signaling, and can be also used for covering nonbiological surfaces, offering them biocompatibility. Food packaging film must possess good mechanical strength. These films should also be able to stop the migration of oxygen, water, fatty acids, and other aromatic components for ensuring food quality and increasing shelf life (Yang et al., 2014). Collagen is extensively used in food industry because of its several properties. It shows good filmforming ability, is resistant to organic solvents, biocompatible, stable, etc. Collagen films show good antioxidant property and are used for the packaging of meat, fish, etc. Artificial sausage casing produced from collagen presents good taste and high transparency. But the disadvantage is that food packaging made from collagen shows poor mechanical strength. For solving this issue, Yang et al. (2014) produced a novel food packaging film using collagen as the major component and sodium alginate as a reinforcing agent. Glutaraldehyde was used as cross-linking agent for improving the strength of the collagen film.

3.1.13 Gelatin Gelatin (Fig. 3.13) is also called gelatine. It is an animal protein produced by the thermal denaturation of collagen (G omezGuillen et al., 2009; Gabor and Tita, 2012). It is obtained from animal skin and bones using dilute acid. It can also be obtained from the skin of fish. Porcine and bovine gelatin sources are the most widely used (Karim and Bhat, 2009). The structure is determined by the properties of collagen from which gelatin is obtained (Staroszczyk et al., 2012).

Properties of biobased packaging material

Figure 3.13 Gelatin.

Typically the structure is -Ala-Gly-Pro-Arg-Gly-Glu-4Hyp-Gly-Pro-. Gelatin contains several glycine residues, proline and 4-hydroxyproline residues. Gelatin is a mixture of single or multi-stranded polypeptides, each having extended left-handed proline helix conformations and contain between 50 and 1000 amino acids. The triple helix of type I collagen obtained from skin and bones, as a source for gelatin, is composed of two a1(I) and one a2(I) chains, each having molecular weight w95 kD, length w0.3 mm and width w1.5 nm. (www1.lsbu.ac.uk)

There are two types of gelatin, depending on whether or not the preparation involves pretreatment with alkali, which converts asparagine and glutamine residues to their respective acids and results in higher viscosity. Acid pretreatment (Type A gelatin) uses pig skin, whereas in contrast, alkaline treatment (Type B gelatin) uses cattle hides and bones. Gelatin is deficient in isoleucine, methionine, threonine, and tryptophan. In the food industry, the applications for gelatin have increased. In food products, these are used as foaming agents, stabilizers, emulsifiers, biodegradable film-forming materials, and microencapsulating agents (G omez-Guillen et al., 2011). Gelatin forms transparent elastic thermoreversible gels on cooling below 35 C, which dissolve at low temperature to give “melt-in-the-mouth” products with useful flavor release (Ledward, 1986). Furthermore, the amphiphilic nature of the molecules provides useful emulsification and foam-stabilizing properties. Upon dehydration, irreversible conformational changes take place that can be used in the formation of surface films (Mogilner et al., 2002). These films are very strong when they contain greater triple-helix content. Gelatin is also used for clarifying wine and fruit juices. Gelatin is the major hydrocolloid used for gelling, but concerns about the possibility of such an animal-derived product containing the prions that cause Creutzfeldt-Jakob Diseasea, plus the requirements by vegetarians, have necessitated looking for alternatives. The combination of the melt-in-the-mouth, elastic, and emulsification properties of gelatin gels is difficult to reproduce.

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The applications of gelatin are mainly based on its gel forming properties. In the food industry, several new applications have been developed for gelatin in products in line with the growing trend to replace synthetic agents with more natural ones (GomezGuille et al., 2011). Global leading players in the gelatin market are: “PB Gelatin (Tessenderlo Group), Gelita AG (Formerly DGF Stoess), Sterling Biotech Ltd., Rousselot SAS, Weishardt Group, Nitta Gelatin and Weifang Ensign Industry Co. Ltd.” (https://factsweek.com/ 410,160/global-industrial-gelatin-market-2018-review). “In Europe, the key players are: Chemcolloids Ltd., Corngroup Inc., Gelita AG, Rousselot S.A.S., Tessenderlo Group, Weishardt Group, Biogel AG, Ewald-Gelatine GmbH, Industrias Ogi SL, Italgelatine SpA, Junca Gelatines SLU, Lapi Gelatine SpA, Nitta-Gelatin, OJSC Mogelit, Reinert Gruppe Ingredients GmbH, SARIA Bio-Industries AG & Co. KG, Sobel NV, Sonac BV, Sterling Gelatin, Trobas Gelatine BV, Verdannet Monnard”(https:// www.asdreports.com). Gelatin is normally graded into categories according to its quality and strength, and the unit is named as “bloom.” A higher bloom number signifies a high quality of gelatin. The color of the gelatin product depends on the type of raw material. The superior quality gelatins are high-molecular-weight compounds and with better gel strength. The factor affecting the demand for gelatin is the growing food industry. “Gelatin is used as a gelling agent in food products such as puddings, yogurts, gummy candies, fruit gelatin desserts, ice creams and marshmallows. The popularity of these food items and the growth of the food industry have contributed to the growth of the gelatin market. The consumption of gelatin has health benefits. It is rich in amino acids and a good source of proteins. It helps in digestion and joint recovery and is also beneficial for the healthy growth of hair and nails. This factor coupled with increasing health-consciousness among the consumers has been stimulating the market growth. Moreover, the increasing applications of gelatin in the end-use industries, such as nutraceuticals, pharmaceuticals, photography and cosmetics, has provided the market with a strong thrust. The market is expected to reach a value of more than US$ 2,800 Million by 2022” (www. grandviewresearch.com; www.abnewswire.com/.../global-gelatin-market-catalysedby-flourishing-food-industr). The food industry accounts for most of the global market share. Based on raw materials, pig skinederived gelatin dominates the market. On the basis of region, Europe is the leading producer of gelatin, accounting for about a half of the total global share. North America, Asia, and South America are other main markets (https://www. fooddive.com/.../20171010-global-gelatin-market-2017-top-key-players).

Properties of biobased packaging material

3.1.14 Soy protein Soy protein is extracted from soybeans. It is being used in different types of foods. The useful properties of soy proteins for food industry are emulsification and texturizing (Vroman and Tighzert, 2009; Gautam and Satish Kumar, 2017). Soy protein also can be used in the production of packaging materials, adhesives, and plastics (Lu et al., 2004; Mohanty et al., 2005; Liu et al., 2010; Tian et al., 2011). This is a good alternative to the fossil fuelebased polymers (Tian et al., 2011). Soy protein exists as (Giancone et al., 2009): • soy flour (SF), which needs less purification e SF contains about 52% proteins and 32% carbohydrates • soy protein isolate (SPI) e SPI contains 90% proteins and 4% carbohydrates • soy protein concentrate (SPC) e SPC contains 70% proteins and 18% carbohydrates SF is the least expensive of these three forms. Soy protein isolate comes in dry powdered form. Soy protein is a main coproduct of soybean oil. It is readily available and renewable and has 18 amino acids. Soy protein shows poor mechanical performance and water sensitivity, so it has found limited applications (Tian et al., 2009). Soy proteins are used in food and nonfood applications. Soybean proteins have several functional properties (Damodaran and Paraf, 1997; Vojdani and Whitaker, 1994). Functional properties are physicochemical properties that change the processing and quality of protein (Vojdani and Whitaker, 1994). The required functional properties for soy proteins change with the type of application, but the different side groups present in soybeans lead to diverse functional capabilities. R&D is continuing to develop novel uses of soybean proteins. For wood adhesive applications, the functional properties include adhesion, water solubility and water resistance, and viscosity. Unmodified soy proteins cannot meet all functional properties required for these applications (Lambuth, 1977). Functional properties can be improved by modifying protein structure/properties such as disulfide bonds, molecular size, and net charge (Vojdani and Whitaker, 1994). Through physical, chemical, or enzymatic modifications, the functional properties of soy protein can be changed (Feeney and Whitaker, 1977). Soy proteins are used for coating paper and paperboard. Soy paper coatings improve surface appearance and impart a smoother surface. These proteins are also used as structuring agents in water-based inks and are preferred to solvent-based inks. Kunte et al. (1997) used casting method for producing films from soy protein isolate and fractions by casting method. The glycerol-plasticized soy protein films were produced from alkaline film-forming solution of 7S, 11S, soy isolate fraction (LSI) (prepared in laboratory) from commercial soy isolate. The 11S films showed higher tensile strength than 7S films (P < .05), whereas soy isolate fraction films showed higher tensile

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strength than commercial soy isolate films (P < .05). Not many differences were found among mean E values and among mean water vapor permeability values of all films (P > .05). The 7S films showed higher total soluble matter and protein solubility values compared to 11S films (P < .05). CSI films were much darker and more yellow in comparison to LSI films (P < .05). Zhong and Sun (2001) examined blends of soy protein isolate with different percentages of polycaprolactone (SPI/PCL) alone or with addition of 0.5, 1.0, 2.0, and 5.0% methyl diphenyl diisocynate (MDI). Tg of SPI was found to reduce with the increase of PCL contents in the blend containing 2% wt MDI. For 50/50 (SPI/PCL) blends, the Tg of SPI reduced with increases in MDI content. Both differential scanning calorimeter, dynamical mechanic analyzer results showed that compatibility between SPI and PCL improved by the addition of MDI. Mechanical properties of the 50/50 (SPI/ PCL) blends increased with the increase of the concentrations of MDI. By increasing PCL concentration and incorporating MDI, water resistance of the blends increased substantially. Liyange et al. (2001) produced edible soy protein film. The protein content in soybean is more than the protein content of cereals grains. Water was used to make casting solutions and glycerol was used as the plasticizer. The pH of the casting solution was adjusted with 2M HCL. Like other grain protein film, the properties of the soy protein isolate film depend on the relative humidity. Tensile strength of soy protein films was comparable with those of conventional packaging materials such as low-density polyethelene. Moisture absorption isotherms were similar in behavior to other proteins. Xiaoqun and Xiuzhi (2002) studied plasticization of soy protein polymer by using polyol-based plasticizers. SPI was blended with polyol-based plasticizers and molded into plastics using a hot press. Thermal properties of the SPI plastics with propylene glycol were reduced to the greatest extent and the plastics with glycerol showed the highest strain at break and plastics with 1, 3-butanediol showed the highest tensile strength. The morphology of the fractured surface of the SPI plastics changed from brittle fracture for the unplasticized SPI to ductile fracture for the plasticized SPI. Water absorption of all the plastics was found to be lower in comparison to unplasticized SPI plastics. Liu et al. (2017) developed a “novel soy protein isolate-based films for packaging using halloysite nanotubes (HNTs), poly-vinyl alcohol (PVA), and 1,2,3-propanetrioldiglycidyl-ether (PTGE). The SPI/HNTs/PVA/PTGE film showed that HNTs were uniformly dispersed in the SPI matrix and the thermal stability of the film was increased. The tensile strength of the SPI/HNTs/PVA/PTGE film was increased by 329.3 percent and the elongation at the break was not changed. The water absorption and the moisture content were decreased by 5.1 percent and 10.4 percent, respectively, compared to the unmodified film. Synergistic effects of SPI, HNTs, PVA, and PTGE on the mechanical properties, water resistance, and thermal stability of SPI films was observed. SPI films

Properties of biobased packaging material

produced from HNTs, PVA, and PTGE showed significant potential as packaging materials” (ijrrpas.com). Cross-linking of soy protein film with formaldehyde or glutaraldehyde at different doses into film-forming solution resulted in an increase in the tensile and barrier properties of the films (Soliman et al., 2007). The dose of formaldehyde, which showed good mechanical and barrier properties, was 0.3 mg/100 mL film-forming solution. When SPI was combined with starch, significant increase in mechanical and barrier properties of plain SPI film was obtained and the best results were achieved using 70/30 w/w ratio of SPI/starch.

3.1.15 Whey protein Whey proteins are a by-product of the cheese industry. These proteins consist of whey protein isolates (WPIs), which are the purer form of such proteins. Another form of whey proteins is whey protein concentrate (Ramos et al., 2012). Whey proteins can produce elastic films (Wang et al., 2013). These proteins are used in packaging as they possess good oxygen barrier and moisture permeability (Ramos et al., 2012; Popovi et al., 2012). WPIs can produce transparent films and coatings having very good oxygen barrier properties (Sothornvit and Krochta, 2000, 2005). WPI-based edible films act as barriers to solute and gas and improve food quality and shelf life (Krochta and De MulderJohnston, 1997; Perez-Gago and Krochta, 2002). But, these films do not possess good mechanical and water vapor barrier properties as they are hydrophilic and are not suitable for widespread use in the food industry (Krochta and De Mulder-Johnston, 1997). Lu et al., 2004; Mohanty et al., 2005; Liu et al., 2010). Films produced with biopolymers from sustainable raw materials can carry active compounds (Mu~ noz-Bonilla and Fernandez- García, 2012); so they are used as active packaging for food. Active packages contain substances that interact with the packaged product (Pereira-de-Abreu et al., 2012; Suppakul et al., 2003), such as antioxidants. In active packages, the active compounds are added into the films rather than directly adding the compounds to foods, providing functional effects at the food surface where the oxidation usually takes place (Coma, 2008). Bioactive packaging materials should be able to keep bioactive compounds like prebiotics, probiotics, encapsulated vitamins or bioavailable flavonoids, in optimum condition until they are released in a controllable way into the food product (Brody, 2005). Bioactive-packaging materials can help to control oxidation of food stuffs and to stop the formation of off-flavors and undesirable textures of food. Bioactive compounds that are encapsulated into the packaging itself are an attractive approach because this would allow the release of the active compounds in a controllable way. (www.fas.org)

Improvement in technologies for preservation of food from microbial spoilage is important to ensure food safety and quality. The functional ingredients commonly used in packages for antioxidant and antimicrobial purposes are butylated

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hydroxytoluene, nisin, benzoate, organic acids, and enzymes. These materials reduce oxidation in model systems of meat or oil products, and also impede microbial growth in food products. Whey protein isolates have been used as a raw material for producing biodegradable polymers. Their film-forming and barrier properties are comparable to petro-based products. But, low-tensile strength and high water vapor permeability are the weaknesses of the films produced from whey protein (Azeredo et al., 2010). Efforts are currently underway to find new applications for proteins and starches, such as production of edible films (Anker et al., 1998; Kokoszka et al., 2010), or films with antimicrobial property (nanoparticles) for effective protection of food products. The interest in “ready-to-eat” and easy-to-consume products increases the obligation for greater control on food quality and safety. Eruption of foodborne diseases has brought about the necessity for alternate methods to control microbial growth in food products (Appendini and Hotchkiss, 2002). Whey protein films do not show any antimicrobial property; so the addition of antimicrobial agents and lysozyme is required for imparting this property (Cagri et al., 2001; Kristo et al., 2008). Another route to impart antimicrobial functionality to packaging films is the use of antimicrobial nanoparticles such as titanium dioxide nanocomposites. Titanium dioxide shows bactericidal activity against several microbes because of its photocatalytic activity.

3.1.16 Zein Zein is a naturally occurring protein and is the main storage protein of corn (Zea mays L.). It is produced during processing of corn and is used to produce a range of thermoplastic products (Biswas et al., 2006; Del Nobile et al., 2008; Reddy and Yang, 2011). Zein accounts for 35e60 percent of total protein in corn and shows a unique amino acid profile. It consists of three quarters of hydrophobic and one quarter of hydrophilic amino acid residues, which defines zein as a prolamine by its solubility that it is only soluble in 50e95 percent alcohol. Zein has three major fractions named alpha-, beta-, and gamma-zein, and a minor fraction which is d-zein, with alpha-zein being the main type zein commercially available in the market (Luo and Wang, 2016). Zein is derived from food, but it is lacking essential amino acids (tryptophan and lysine) and thus has a negative dietary nitrogen balance. So, zein has not been used in food products for human use. Nonetheless, its unique physicochemical properties have made zein a popular food biopolymer in the development of nanoscale delivery systems for nutrients. (Shukla and Cheryan, 2001)

Zein contains prolamines, which are alcohol-soluble proteins. These proteins are present in corn endosperm and are mainly used in specialty food and pharmaceutical coatings. Film-forming properties of zein have been known for a long time and are the basis for most of the industrial applications of zein (Padua et al., 2000; Andres, 1984). Films are produced by casting, drawing, or extrusion methods (Ha, 1999; Lai and Padua, 1997; Reiners et al., 1973). Zein-based films are brittle so plasticizers are required for making

Properties of biobased packaging material

them flexible. These films can be used in edible coatings and biobased packaging (Padua et al., 2000). The presence of a high amount of nonpolar amino acids gives corn zein a relatively hydrophobic nature. This leads to superior oxygen barrier properties but poor mechanical properties (Ozcalik and Tihminlioglu, 2013). Zein was first discovered by Gorham in 1821. Osborne developed the first process for extraction of zein from corn gluten meal using 95% ethanol. This process was patented. Swallen (1938) obtained a series of patents on zein production using different alcohols of varying concentrations and additives. Zein became commercially available in 1938 and found application in coatings, fibers, films, plastics, adhesives, and inks. Zein is mixed with vegetable oils and glycerin as plasticizers and is used for waxing or glaze, for improving the shelf life of nuts, candies, and pharmaceutical tablets by acting as a water and oxygen barrier. VirginiaeCarolina Chemical Corporation in 1948 produced Zein fibers with the commercial name of Vicara. It was marketed for its claims of washability, resistance to moths and mildew, and the warmth of wool. Corn zein protein coatings are used in pharmaceutical or nutraceutical industry for coating tablets for better appearance, medications, and ease of swallowing. Corn zein proteins are hydrophobic because of the presence of nonpolar amino acids. The hydrophobic properties provide oxygen barrier properties. Zein protein is also used in food and beverage packaging. There are several hundred patents on applications of zein and renewed interest due to its biodegradability and potential nanotechnology applications, but its current high price is still a limitation. The potential market for zein is expected to be good, taking into account the following facts: 1. Great demand for 100% biodegradable packaging and films 2. Low margins in some sectors of the corn processing industry eager to find highervalue outlets for their coproducts 3. Lessons learned from previous attempts at corn-based “biodegradable” plastics; these were mostly starch-based and did not do well for several reasons. Assuming that “biodegradability” can improve the value of zein-based films and packaging, this market could use a substantial portion of the zein in the 5 billion bushels of corn presently processed into food, feed, and industrial products in the United States today (faculty.fshn.illinois.edu/wmcheryan/avcpro.htm). However, the cost of zein must be reduced and the quality improved. Shukla and Cheryan (2001) reported that Zein is the main protein of corn and contains 45%e50% of the protein in corn. Zein isolates are not used directly for human consumption because of their negative nitrogen balance and poor solubility in water. The zein and its resins produce tough, glossy, hydrophobic grease-proof coatings and are resistant to attack by microorganisms. These properties are commercially important. Zein can be used in coating, fiber, adhesive, ceramic, ink, cosmetic, textile, chewing gum, and

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biodegradable plastics. These applications look promising, but there is a requirement to develop low-cost manufacturing methods. The properties of zein are reported in terms of its composition, structure, solubility in different solvents, and gelation properties. Velde and Kiekens (2001) found that flexural and tensile properties were correlated and the tendencies found were probably the same as found when comparing flexural properties. Tensile properties were found best for the densest polymers, particularly for PGA, and PCL was found to be the weakest polymer having unusual high strain at failure. Molecular weight was found to play a very important role in the mechanical properties. One of the most promising applications of zein appears to be for biodegradable films and plastics used for packaging. Worldwide demand for such products has been estimated to be 15000e250000 ton per year. Unplasticized zein films were found too brittle for most applications but the use of crosslinking agents (such as citric acid, formaldehyde, butane tetracarboxylic acid) increased tensile strength by two to three times. Zein films can be modified and strengthened by adding highly stable silicate complexes into protein structures. They possess higher strength and lower gas permeability than unmodified films. The marketability of zein-based plastic films can be improved by incorporating food-grade anti-microbial compounds into the packaging film. (www.lucidgroup.com; Lee et al., 1998; Padgett et al., 1998; Parris and Coffin, 1997).

Excellent reviews on protein-based edible films and coatings have been published (Gennadios et al., 1994; Baker et al., 1994). Biodegradable plastics produced from zein are destructured starchezein composites and zein plasticized with fatty acids. “Mixtures of zein, starch, and a crosslinking agent such as aldehyde, epichlorohydrin are compression molded to produce water-resistant plastics. Such plastics undergo 60 percent biodegradation in 180 days and have been used to make bottles, sheets, films, packaging materials, pipes, rods, laminates, sacks, bags and powders” (www.omicsonline.org; Cole and Daumesnil, 1989; Jane and Spence, 1995; Spence et al., 1995). Glycerineplasticized zein films having 1%e8% starch had reduced water vapor permeability and were more resistant to water as compared to unplasticized films (Parris et al., 1997). Composites of fatty acid and zein are produced by plasticizing zein with oleic and linoleic acids followed by precipitation in cold water (Lai et al., 1997; Lai and Padua, 1997; Padua et al., 1997). These plastics show higher ductility and tensile strength in comparison to other biopolymers (www.lucidgroup.com).

3.1.17 Casein Casein is a protein derived from milk and is an exceptional candidate for biodegradable films (Bonnaillie et al., 2014). It can be processed easily because of its random coil structure and constitutes about 80% of the total proteins in milk (Ginger and Grigor, 1999). Casein is available in several different by-products from the dairy industry. These include calcium and sodium caseinates (Dangaran et al., 2009; Kalicka et al., 2010). Casein is able to provide several polar functional groups, such as hydroxyl and amino groups, to the film

Properties of biobased packaging material

matrix and create a good barrier to oxygen and other nonpolar molecules (Tomasula et al., 2003). Casein films can be combined with other packaging materials for protecting products susceptible to oxidation. During drying, pure casein films shrink and get brittle; so, edible plasticizers, such as glycerol, are used for increasing the free volume of the polymer and to render casein films more flexible, by reducing their Tg. Edible casein/glycerol films under normal conditions have good tensile strength and moderate elasticity, but the barrier properties of casein films are affected by the presence of glycerol (Abu Diak et al., 2007; Longares et al., 2005; Ghosh et al., 2009; Dangaran et al., 2006; Mauer et al., 2000; Tomasula, 2009; Vieira et al., 2011). Processing with suitable plasticizers at temperatures of 80e100 C, materials can be produced with mechanical performance varying from stiff and brittle to flexible and tough performance. Casein melts are highly stretchable which makes them suitable for film blowing. Casein films have an opaque appearance. Casein materials do not dissolve directly in water, but they show approximately 50 percent weight gain after 24 hours of immersion. The main drawback of casein is its relatively high price. Casein was used as a thermoset plastic for buttons in the 1940’s and 1950’s and is still used today for bottle labelling due to its excellent adhesive properties. (www.bc.bangor.ac.uk; Dhall, 2013)

Casein has random coil nature and can form electrostatic, hydrophobic, and hydrogen bonds, so the films are formed easily (Saez-Orviz et al., 2017; Perez-Gago, 2012). Methods for improving the functional properties of films produced from casein and casein derivatives are available (Wihodo and Moraru, 2015). However, there are not many reports studying the protector effect of these biopolymers regarding microbial contamination. Since each natural polymer has its own characteristics for packaging applications, biopolymers are expected to satisfy the functional needs of desirable barrier and mechanical properties. Casein produces a packaging film which is degradable, edible and much better at preventing spoilage than plastic. Casein film has smaller pores than existing packaging options, which makes it up to 500 times better than plastics at locking out oxygen. Besides reducing waste by increasing the shelf life of food, the milk protein base also means the packaging will biodegrade rapidly when thrown out, or can just be eaten along with its contents. The protein-based films are very good oxygen blockers that help in preventing food spoilage. When used in packaging, they are able to prevent food waste during distribution along the food chain. (mdpi.com; https://newatlas.com/casein-milk-packaging/45005/)

Researchers used pure casein during early attempts at developing casein packaging. It was not able to block oxygen effectively, and the material produced was not very flexible and dissolved very rapidly in water. To solve these problems, the researchers used citrus pectin to make the film more durable and increase its resistance to heat and humidity. The casein packaging still needs to be wrapped in protective outer layers for keeping it clean and dry as it is edible, so while it may not completely replace plastics, it can substantially reduce the quantity used. There are several coating applications for this product.

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A sprayable version may open up further applications, like keeping cereal crunchy in milk which is a healthier option to the present method of coating it in sugar. It could also be used as a laminate-like barrier between food and its packaging for instance keeping pizza boxes from getting greasy. With the US FDA recently tightening the use of existing perfluorinated grease-proofing agents, the researchers are suggesting that casein may provide a safe replacement. (www. grandviewresearch.com) Milk-protein-based packaging has clear cut advantages over petroleum-based plastics but it should be noted that dairy industry itself is not without environmental problems, which may make other biodegradable packaging based on waste materials such as fruit peels and crustacean shells a more attractive option. (www.grandviewresearch.com)

USDA researchers are improving the casein packaging and producing samples of the film for the Texan company. They are hoping to launch the material in the market in the next few years. The research was presented at the National Meeting and Exposition of the American Chemical Society in 2016. IMARC’s latest study provides a technocommercial roadmap for setting up a casein manufacturing plant. “The global casein market grew at a CAGR of around 3 percent during 2010e17 and reached a volume of 326.8 Thousand Tons in 2017. The major factors driving the demand of this product are several applications in the food industry, growing demand of protein-based health drinks, longer shelf life, changing dietary habits, population growth, increasing disposable incomes and increasing demand from developing markets” (www.imarcgroup.com/casein-market).

3.1.18 Gluten Gluten is the major storage protein in wheat and corn. Wheat is able to form a viscoelastic dough. Mechanical treatment of gluten leads to formation of disulfide bridge produced by the cysteine that is present in abundance in gluten. The disulfide bridges form a strong, viscoelastic and large dough. So, processing is more difficult than in the case of casein because the disulfide cross-links of the gluten proteins have to be reduced with the help of a reducing agent. Depending on the amount of plasticizer contents, processing temperatures are in the range of 70e100 C. Mechanical properties may vary in the same range as in case of caseins. Gluten plastics show high gloss and show good resistance to water under certain conditions. They do not dissolve in water, but they absorb water during immersion. Because of its low price and abundance, research on the use of gluten in edible films, adhesives, or for thermoplastic applications is in progress (www. biocomposites.bangor.ac.uk). Among proteins wheat gluten has been widely used for edible film (Cousineau, 2012; Sharma et al., 2016; Guo et al., 2012; Chen, 1995). Wheat gluten is available at economical cost and is an interesting raw material for the development of biopolymers (Kaushik et al., 2015). Wheat gluten is not a simple thermoplastic material and has a quite narrow temperature range in the extrusion to produce network structure. Gluten extrudates

Properties of biobased packaging material

plasticized by glycerol are solid-like and elastic (Guilbert et al., 2002). Redl et al. (1999) were able to produce glycerol-plasticized wheat gluten rods under different conditions by twin-screw extruder. Plasticizers increase film flexibility because of their ability to reduce internal hydrogen bonding between polymer chains while increasing molecular volume (Koskinen et al., 1996). The production of protein-based films usually requires the addition of a minimal content of plasticizer for reducing its brittleness. Film plasticizers weaken intermolecular forces between adjacent polymer chains, resulting in an increased film extensibility and flexibility with reduced elasticity, mechanical resistance, and barrier property of the films. Plasticizers commonly used are polyols and mono-, di-, and oligosaccharides. Glycerol, as a plasticizer, has been added into most hydrocolloid films (Banker, 1966). Wheat gluten sheet plasticized with glycerol was produced with a twin screw extruder and the translucent sheet was formed when temperature of the melt was w137 C (Hochstetter et al., 2006). Glycerin and water plasticized with cast wheat gluten films reduced puncture strength, improved elasticity and extensibility and water vapor transmission rate (Gontard et al., 1993). Without addition of plasticizer the films become too brittle to handle. Edible films and coatings must be organoleptically and functionally compatible with foods besides the barrier efficiency. Coatings are either added to or made directly on foods when films are independent structures that can wrap food after they are produced (Debeaufort et al., 1998). Food components, edible films and coatings must be tasteless so they are not detected during the consumption of the edible-packaged food product (Contreras-Medellin and Labuza, 1981). When edible films and coatings have a significant taste and flavor, their sensorial characteristics should be compatible with those of the food (Biquet and Labuza, 1988). Wheat gluten has excellent viscoelastic properties (Cousineau, 2012). Dry processing or solvent casting methods are used to produce wheat gluten films. Gluten films obtained by dry processing are produced with very little water and a small amount of plasticizer in comparison to solvent cast films but are sometimes much thicker (Lagrain et al., 2010; Pommet et al., 2005; Kayserilioǧ;lu et al., 2003). Solvent cast gluten films often use an aqueous ethanol solvent for dissolving the gluten since gluten is soluble in ethanol (Olabarrieta et al., 2006). However, the industry trend toward greener solvents is encouraging efforts to produce gluten films using water as the only solvent (Gu Jer^ ome, 2010; Kerton, 2009). In either case, the process is to disperse the gluten and plasticizer in the solvent and then alter protein interactions in solution by methods like pH adjustment, temperature, sonic, or chemical treatments for breaking disulfide bonds (Lagrain et al., 2010; Gennadios et al., 1993). The final gluten solution is cast and dried in a controlled environment (temperature, relative humidity) to remove the solvent and obtain a film. As the solvent evaporates, the gluten concentration in the film increases and promotes intermolecular bond formation so as to produce the desired three-dimensional gluten network (Lagrain et al., 2010). In solvent cast gluten films, alkaline conditions above

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the isoelectric point of gluten, 7.5, tend to produce stronger films, due to increased gluten polymerization and cross-linking at higher pH (Gennadios al., 1993; Lagrain et al., 2010; Olabarrieta et al., 2006). The preparation of a gluten film by casting produces an open, loose protein network that is conducive to hydrophobic interchain bonding and also cross-link formation when exposed to heating and stirring during film preparation (Lagrain et al., 2010; Jerez et al., 2005; Micard et al., 2001). Typically, glycerol and/or water are used as plasticizers because they are very effective (Lagrain et al., 2010). The reason for using plasticizer, such as glycerol, is to improve film flexibility. Glycerol is a polar molecule and breaks up some of the hydrogen bonds between protein chains. In the absence of glycerol, gluten forms a brittle film due to the high glutamine content in gluten (Shewry et al., 2002; Gontard et al., 1993; Belton, 1999; Lagrain et al., 2010). Heating wheat gluten encourages disulfide interchange reactions. Heating induces protein unfolding, which in turn exposes hydrophobic groups and cysteine residues, which are generally hidden inside the protein molecule (Domenek et al., 2002). The exposed cysteine residues restabilize the molecule by participating in disulfide interchange reactions with other cysteine residues. The disulfide bonds in the system do not increase, but the interchange of disulfide bonds throughout the protein shifts the bonds from intramolecular to intermolecular and locks the protein.

3.2 Polymers produced from traditional chemical synthesis from biobased monomers Use of traditional chemical synthesis for the production of polymers gives a wide range of possible “biopolyesters.” Currently, polylactic acid (PLA) shows the highest potential for the production of renewable packaging materials (Weber, 2000). But, a diverse range of other biopolyesters also can be produced. In fact, in the future all the traditional packaging materials produced from mineral oil will be produced from renewable monomers produced by fermentation. But, this method is not economically viable today because of the cost of the production of the monomers. PLA producers have been able to overcome this obstacle successfully.

3.2.1 Polylactic Acid PLA (Fig. 3.14) has been known since 1845, however, it was commercialized in the beginning of 1990s. Currently PLA is the most promising and popular material ( Johansson et al., 2012; Weber, 2000; Hu, 2014; Babu et al., 2013; Gabor and Tita, 2012). PLA contains the basic constitutional unit lactic acid (2-hydroxypropionic acid) and belongs to the family of aliphatic polyesters. The monomer lactic acid is the hydroxyl carboxylic acid. Lactic acid can be produced by fermentation of carbohydrates. These may be agricultural products like corn, wheat or alternately may consist of waste from agriculture or the food

Properties of biobased packaging material

Figure: 3.14 Chemical structure of polylactic acid (PLA).

industry, such as molasses, whey, green juice, etc. (Garde et al., 2000; S€ odergaard and Inkinen, 2011). PLA can be produced economically by the use of green juice, which is a waste product from the animal feed industry (Garde et al., 2000). Other renewable raw materials can be also used, but corn starch has the benefit of providing a high-quality substrate for fermentation. This results in a high-purity lactic acid, which is needed for an efficient synthetic process. The basic building block for PLA is lactic acid, which is a three-carbon chiral acid that occurs naturally predominantly in the L() form. Therefore, the abbreviation PLLA is mostly used, resulting in the polymer name poly(L-lactide). The terms polylactide and poly(lactic acid) are used interchangeably in the literature. The use of the term polylactide is more appropriate because this refers to the polymer produced from the lactide dimer by the commonly used ring-opening polymerization. On the other hand, PLA would normally be used to describe the polymers produced by other methods, for instance, polycondensation (Henton et al., 2005; S€ odergaard and Inkinen, 2011). Table 3.8 shows the advantages of PLA over traditional petroleum-based polymers. PLA can be produced using the following three methods: 1. “Direct condensation polymerization 2. Azeotropic dehydrative condensation 3. Polymerization through lactide formation and ring opening polymerization” (Fig. 3.15) (Hu, 2014; Auras et al., 2004; Lim et al., 2008; Hartmann, 1998). The first method generates water during each condensation step and results in lowmolecular-weight material because of undesired chain transfer (Auras et al., 2004; Benson et al., 1992). The third method is used for producing commercially available high-

Table 3.8 Advantages of PLA over traditional petroleum-based polymers.

Can be obtained from a renewable agricultural source (e.g., corn or potato); Provides significant energy savings; Recyclable and compostable; Helpful for improving agricultural economies; Their physical and mechanical properties can be tailored through design of the different polymer architectures or processing methods. Based on www.biomasspackaging.com/the-pros-and-cons-of-polylactic-acid-pla-bioplastic-the-.

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Figure 3.15 Synthesis of high-molecular-weight PLA from L- and D-lactic acids. (Reproduced with permission from Lim, L.T., Auras, R., Rubino, M., 2008. Processing technology for poly(lactic acid). Prog. Polym. Sci. 33, 820e852.)

molecular-weight PLA, which can be produced based on this method as no water is produced during the polymerization process. Nature Works LLC has developed an economical method for the production of PLA (Erwin et al., 2007). Low-molecular-weight prepolymer lactide dimers are produced during a condensation process. Lactides are converted during the second step into high-molecular-weight PLA via ring-opening polymerization by the use of selected catalysts. Different types of PLA and PLA copolymers can be produced depending upon the ratio and stereochemical nature of the monomer (L or D). The PLA properties depend on the ratio of the D and L forms of the lactic acid, which are presented in Table 3.9 for several blend ratios. PLA shows some similarities with hydrocarbon polymers like polyethylene terephthalate (PET). So this polymer is of commercial interest. It has several unique properties listed below: • good transparency • glossy appearance • high rigidity • ability to withstand different processing conditions

Properties of biobased packaging material

Table 3.9 Glass transition and melting temperature of PLA with various ratios of L-monomer composition. Copolymer ratio

Glass transition temperature 8C

Melting temperature 8C

80:20 (L/DL)-PLA 56 125 85:15 (L/DL)-PLA 56 140 90:10 (L/DL)-PLA 56 150 95:5 (L/DL)-PLA 59 164 100:0 (L/DL)-PLA 63 178

56 66 56 59 63

125 140 150 164 178

Based on Garlotta, D., 2001. A literature review of poly (lactic acid). J. Polym. Environ. 9(2):63e84.

PLA is a thermoplastic polymer and can replace traditional polymers like PET, PS, and PC for packaging, electronic, and automotive applications (Majid et al., 2010). The mechanical properties of PLA resemble those of conventional polymers, but the thermal properties are not good because of the low Tg of 60 C. This issue can be solved by changing the stereochemistry of the polymer and mixing with other polymers and processing aids for improving the mechanical properties. When the ratio of L and D isomer is varied, the crystallinity of the final polymer is strongly affected. But, extensive research is needed for improving the properties of PLA for suiting different applications. PLA shows a high potential for packaging applications. “PLA properties are related to the ratio between the two meso forms (L or D) of the lactic acid monomer. Use of 100% L-PLA results in a material having a very high melting point and high crystallinity. If a mixture of D- and L-PLA is used instead of just the L-isomer, an amorphous polymer is obtained with a Tg of 60 C, which will be too low for some packaging applications (Sinclair, 1996). A 90/10 percent D/L copolymer produces a material which can be polymerized in the melt, oriented above its Tg and can be easily processed showing very high potential of meeting the requirements of a food packaging. The temperature of processing is between 60 and 125 C depending on the ratio of D-to L-lactic acid in the polymer. PLA may be plasticized with its monomer or alternatively, oligomeric lactic acid and the presence of plasticizers reduces the Tg. PLA offers several opportunities to tailor the properties of the finished material or package. PLA is the first biobased material produced on a large scale. PLA may be converted into blown films, injected molded objects and coatings”(www.biocomposites.bangor.ac.uk). PLA can be processed on standard converting equipment with minor modification but its material properties should be considered for optimizing the conversion of PLA to molded parts, films, foams, and fibers (Lim et al., 2008). There is an interest in using PLA for producing packaging materials for food applications, but there are several technical issues that need to be solved. By using infrared scanning technology, “PLA

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can be separated from PET but the required infrastructure is not available. Industrial scale composting facilities are also not common. Given that the so-called skeleton waste from tray thermoforming can represent 50 percent of the incoming film, there is a requirement for cost-effective utilization of PLA waste. This challenge is complicated by the reduction in molecular weight that certainly occurs when melt processing PLA” ( Johansson et al., 2012). A company in Belgium, Galactic, has developed a process for recovering monomers from PLA to be used for later PLA synthesis (LOOPLA). This could be implemented widely if PLA volumes for recycling were enough. PLA is used in several applications. It has been mostly used in food packaging (including food trays, tableware such as plates and cutlery, water bottles, candy wraps, cups, etc.). Of all the biopolymers, PLA has one of the highest mechanical strengths and heat-resistance property, but, it is not appropriate for use in electronic devices and other engineering applications. In Japan, NEC Corporation has produced a PLA using carbon and kenaf fibers having better thermal and flame retardancy properties. Fujitsu has developed a polycarbonate blend with PLA for making computer housings. PLA has been used in chemical and automotive industry. One of the drawbacks of processing PLA in the molten state is its tendency to undergo thermal degradation, which is related both to the residence time and process temperature in the extruder (Lim et al., 2008). The thermal degradation of PLA can be attributed to:

1. hydrolysis of the ester linkages by trace amounts of water, which occurs more or less randomly along the backbone of the polymer, 2. zipper-like depolymerization 3. oxidative, random main-chain scission 4. intermolecular transesterification to monomer and oligomeric esters 5. intramolecular transesterification resulting in formation of monomer and oligomer lactides of low molecular weight. (literatur.ti.bund.de) Above a temperature of 200 C, PLA can degrade through intra- and inter-molecular ester exchange, cis-elimination, and radical and concerted non-radical reactions. This results in the formation of carbon monoxide, carbon dioxide, acetaldehyde, and methyl ketene. (literatur. ti.bund.de) Thermal degradation of PLA can take place by a non-radical, backbiting ester interchange reaction involving the hydroxyl chain ends depending on the point in the backbone at which the reaction occurs, the product can be an oligomeric ring structure, a lactide, or acetaldehyde plus carbon monoxide. At temperatures higher than 270 C, homolysis of the polymer backbone can take place. The formation of acetaldehyde will increase with increasing process temperature, with the highest proportion formed at 230 C. Although acetaldehyde is considered to be non-toxic and is naturally present in many foods, the acetaldehyde produced during melt processing of PLA should be reduced, particularly if the converted PLA is to be used for food packaging. (revistapolimeros.org.br)

Properties of biobased packaging material

The migration of acetaldehyde into the contained food can result in off-flavors. This will affect the organoleptic properties and consumer acceptance of the product (Lim et al., 2008). Methods for improving the melt stability of PLA are described in various patents (Lim et al., 2008). Polycarbodiimide (CDI) was found to improve the thermal stability of PLA during processing. Addition of CDI at dose level of 0.1e0.7 wt percent stabilized PLA at 210 C for up to 30 min. CDI could react with the residual or newly produced moisture and lactic acid, or carboxyl and hydroxyl end groups in PLA, and thus impede thermal degradation and hydrolysis of this polymer (Yang et al. 2008). The melt stability of PLA varies from supplier to supplier because of the use of different technologies (Lim et al., 2008). Besides biodegradability, a main advantage of PLA is that it can be processed on common process equipment. The thermal and mechanical properties of PLA are dependent on the ratio and the distribution of L- and D-LA in the polymer chains. Both amorphous and semicrystalline type of PLAs show Tg between 50 C and 70 C. Native PLAs are brittle at room temperature. PLA only consisting of L-LA blocks is semicrystalline because of the high structural regularity. The crystalline regions (up to 37%) provide additional mechanical strength, particularly at high temperatures (Perego et al., 1996). The melting temperature of the crystals is usually about 180 C (Lim et al., 2008). One of the important properties of a semicrystalline thermoplastic is the rate at which it recrystallizes upon cooling from the melt. Fast and spontaneous crystallization is needed for several plastic applications with short-cycle times. Pure PLLA crystallizes spontaneously, but crystallization rate reduces with increasing content of D-LA (Saeidlou et al., 2012). Less pure PLLA thus often contains a quasi-amorphous phase and shows poor mechanical properties. For controlling the PLA crystallinity, several nucleating agents have been examined. Nanoparticles, talc, and nanoclay are found to be good nucleating agents for PLA. PLLAs remain amorphous below 90% L-LA content (Saeidlou et al., 2012). As the monomers LLA and D-LA are enantiomers, PDLA plastics show the same properties like the corresponding PLLAs. If both L-LA and D-LA chain structures are present in a PLA plastic, strong interactions between these complementary structures can form a very stable stereo complex. The effect is most noticeable in PLAs containing equimolar amounts of L- and D-LA, e.g., in 1:1 blends of pure PLLA and PDLA (stereo complex PLA (scPLA)). New processing technologies have expanded the applications of PLA beyond the initial scope of biodegradable packagings. These include several durable applications such as bottles, casings of IT products, cellular phones, films, and textiles ( Jamshidian et al., 2010). IBM is developing a PLA-ABS blend that could replace polycarbonate/ acrylonitrile butadiene styrene, the largely used plastic material in IT products. The technical challenge is to obtain sufficient flame retardancy. Nature Works LLC, USA, is the key supplier of PLA. This company is selling PLA under the brand name Ingeo. The production capacity is 100,000 ton/year. There are

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Table 3.10 Suppliers of PLA. Name of the company

Brand name/polymer type

Nature Works, USA Futerro, Belgium Tate & Lyle, Netherlands Purac, Netherlands Hiusan Biosciences, China Jiangsu Jiulding, China Teijin, Japan Toyobo, Japan Synbra, Netherlands

Ingeo Futerro Hycail Purasorb Hisun Biofront Vylocol Biofoam

Based on Babu, R.P., O’Connor, K., Seeram, R., 2013. Current progress on bio-based polymers and their future trends. Prog. Biomater. 2(8), 1e16.

several other producers of PLA based in the United States, Europe, China, and Japan. Several grades of PLA suitable for different industrial applications, such as automobile, electronics, medical devices, and commodity applications, have been developed. These are presented in Table 3.10 (Babu et al., 2013; Doug, 2010; Ravenstijn, 2010). The Dutch lactide producer Purac is providing lactides for PLA production. The world’s first D-lactide production was started in 2009 (Spain, ktpaa). It is presently being used for producing heat-resistant scPLA foam that can be a biodegradable substitute for expandable polystyrene. PLA prices have substantially reduced in recent years, but they are not competitive with commodity plastics. NatureWorks LLC is expecting to reach cost parity with PET and PS because of an increased economy of scale in the near future. PLA has been recognized as safe (GRAS). It has been approved for use in food packaging, including direct-contact applications (Conn et al., 1995; Tawakkal et al., 2014). PLA is an excellent polymer for packaging applications because of its close similarity to commercial thermoplastics like PET (Auras et al., 2005). PLA has been developed for a variety of primary packaging applicationsdoriented and flexible films, extruded and/or thermoformed packages suitable for applications such as food and beverage containers, cups, overwrap, blister packages, and also coated paper and board (Tullo, 2000; Groot et al., 2011). A Danish dairy company has used biodegradable PLA for yoghurt cups produced from high-impact polystyrene ( Jessen, 2007). PLA has been used for the production of lunch boxes and fresh food packaging (Mutsuga et al., 2008), and containers for packaging of bottled water, bottled juices, and yogurts (Ahmed et al., 2009). Blends of PLA with starches, proteins, and other biopolymers have also been examined for developing completely renewable and degradable packaging materials (Raghavan and Emekalam, 2001; Ke and Sun, 2003; Suyatma, 2004; Yew et al., 2005; Bhatia et al., 2007).

Properties of biobased packaging material

The use of PLA for use in antimicrobial packaging has been studied (Mustapha et al., 2002; Rhim et al., 2009; Chen et al., 2012; Li et al., 2012a; Jamshidian et al., 2013; Fei et al., 2014). There are several patents on PLA-based materials containing antimicrobial agents (Auras et al., 2010; Buonocore et al., 2012; Chen et al., 2012; Liu et al., 2012). “Several substances such as organic acids, bacteriocins (nisin), plant extracts (lemon extract), essential oils and extracts (for example, thymol), enzymes (lysozyme), chelating agents (EDTA), metals (silver) have been incorporated into PLA to provide antimicrobial activity. In particular, PLA with the addition of natural antimicrobial agents such as nisin, lysozyme, and silver zeolite has shown inhibitory actions against selected microorganism such as Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Micrococcus lysodeikticus. Natural antimicrobial agents have also been incorporated into coatings on the surface of PLA and these were shown to be effective against spoilage and pathogenic microorganisms (Del Nobile et al., 2009; Jin et al., 2009; Liu et al., 2009a; Rhim et al., 2009). According to Jamshidian et al. (2010), only a few studies have examined the potential of PLA in general AP applications although there are many examples that use PLA in antimicrobial food packaging applications” (literatur. ti.bund.de).

3.2.2 Polybutylene succinate Polybutylene succinate (PBS) is also referred to as polytetramethylene succinate. It is a biodegradable aliphatic polyester and is a thermoplastic polymer resin belonging to the polyester family. It is produced by condensing succinic acid with 1,4 butanediol. It gives plastic producers a building block for biopolymer compound and has properties similar to polypropylene. According to the USDA, it is among the 12 most promising chemical biobased building blocks for the future. Because of its superior mechanical properties and processability, it can be used in several applications via conventional methods such as extrusion, injection, or blown process. It can be used as a substitute for PP and PET and can replace PLA in several applications, and polyolefin and polystyrenes in some applications. Fig. 3.16 and 3.17 show PBS and its production route. The mechanical properties of PBS are comparable with those of PE and PP. The favorable properties coupled with ease of processing has resulted in emergence of several application areas across diverse end use industries.

Figure 3.16 Polybutylene succinate.

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Figure 3.17 PBS and its production route. (Reproduced with permission from Succinity GmbH - A Joint Venture of BASF and Corbion. http://www.succinity.com/images/succinity_broschure.pdf.)

PBS and their blends are used in packaging film, mulch film, bags, flushable hygiene products, coffee capsules, fishing nets, wood plastic composites, composites with natural fibers, agriculture, fishery, forestry, construction, pharmaceutical, consumer goods, electronics and electricals, textile, automotive, interiors and other industrial fields. It is also used to produce bowls, plates, plastic utensils, and diapers (Weraporn et al., 2011; Liu et al., 2009a,b; Bhatia et al., 2007; Lee and Wang, 2006; Cornelia et al., 2011; Jian-Bing et al., 2011; Jun and Bao-Hua, 2010a,b; Jung et al., 2009). PBS has been used in flushable hygiene products and also used as a nonmigrant plasticizer for PVC. It is also used in foaming and food packaging applications. In the packaging industry, it has gained considerable interest for substituting nonbiodegradable PE, PP, and PS plastics. PBS shows high flexibility, heat resistance, and good biodegradability so it is an excellent biopolymer. It has high biomass utilization efficiency in comparison to other biobased building blocks. By blending it with other polymers, its performance can be tuned for specific applications. A new initiative taken by the World Economic Forum, called New Plastic economy, is encouraging the use of this biopolymer. Several companies are now focusing on biobased PBS. This biopolymer will become an important source of biobased material for food packaging in the future. PBS is produced with monomers, succinic acid and 1,4-butanediol, obtained by bacterial fermentation. The annual production capacity of biobased succinic acid reached 200,000 tons in 2015 (www.succipack.eu/images/Leaflet.pdf). In Japan, Mitsubishi Chemical Company in collaboration with Ajinomoto has developed biomass-based succinic acid for commercializing biobased PBS. Royal DSM, the global life sciences and materials sciences company, and the French starch and starch derivatives company Roquette Freres, have developed a fermentation process for the production of succinic acid, 1,4-butanediol and subsequent production of PBS (Babu et al., 2013). Bioamber and Myriant have developed a process for producing monomers by using fermentation technology. Many companies are developing technologies for the production of PBS (Table 3.11) (Doug, 2010; Ravenstijn, 2010).

Properties of biobased packaging material

Table 3.11 Suppliers of PBS. Name of the company

Brand name/polymer type

BASF, Germany Dupont de nemours, USA Hexing Chemical, China Ube, Japan IPC-CAS, China IRE Chemical Kingfa, China Mitsubishi Gas Chemical, Japan Showa, Japan SK Chemicals. Korea DSM, Netherlands

PBS PBST PBS NA PBS, PBSA Korea Enpol, PBS, PBSA PBSA PBS, PES, PBSLa Bionelle PBS, PBSA, PBS Skygreen NA NA

PBSA, poly(butylene succinate adipate). Based on Babu, R.P., O’Connor, K., Seeram, R., 2013. Current progress on bio-based polymers and their future trends. Prog. Biomater. 2(8), 1e16.

Conventional processes for the production of 1,4-butanediol use acetylene and formaldehyde, which are fossil fuel feedstocks. The biobased process uses glucose from renewable raw materials for producing succinic acid followed by a chemical reduction to produce butanediol. PBS is produced by direct polymerization, transesterification, and condensation polymerization reactions. PBS copolymers are produced by using a third monomer such as adipic acid, succinic acid, and sebacic acid, which are also produced from renewable raw materials (Bechthold et al., 2008). PBS is a semicrystalline polyester. Its melting point is higher in comparison to PLA. Its mechanical and thermal properties depend on the crystal structure and the degree of crystallinity. The melting point of PBS is higher than that of PLA (Nicolas et al., 2011). PBS shows a good tensile and impact strength with moderate rigidity and hardness and shows crystallization behavior and mechanical properties similar to those of polyolefin such as polyethylene. The melting temperature is w115 C and Tg is w 32 C. PBS is tougher in comparison with PLA, but has a lower rigidity and Young’s modulus. By changing the monomer composition, mechanical properties can be adjusted for suiting a particular application (Liu et al., 2009a). PBS shows poor mechanical flexibility, which limits the applications of 100% PBS-based products. But this can be solved by blending PBS with PLA or starch to substantially improve the mechanical properties, providing properties similar to those of polyolefin (Eslmai and Kamal, 2013; Zhao et al., 2010). Electrochemical synthesis is a common process for producing succinic acid from fossil fuels. This process gives high yield and the cost is lower. The fermentation process for production of succinic acid shows many benefits in comparison to the chemical process. Fermentation process uses sustainable raw materials and energy consumption is reduced. Several companies are now scaling up the process for production of

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biosuccinate, which traditionally suffers from high downstream processing cost and poor productivity. According to DIN EN 13432, PBS is a biodegradable and compostable polyester. It was exclusively produced from fossil raw materials in the past, but now it is 100% biobased depending on the selection of monomers (www.succinity.com/images/succinity_ broschure.pdf). PBS is expected to grow from the availability of biobased succinic acid in comparison to petrochemical feedstocks. There are a few producers producing PBS on a commercial scale and additional capacities are expected to start up soon. PBS is mostly used in applications where biodegradability is an advantage, such as in packaging (films and boxes) and agriculture (mulch films). The development of the production capacity of biobased succinic acid allows the production of (50%) biobased PBS already today, and production of 100% biobased PBS is possible with a further transition to biobased butanediol. The price of PBS is expected to drop in the future with the increase of scale of production and improvement in technology. Showa Highpolymer (Shanghai, China) has produced PBS and PBSA from petrochemical sources for many years. The polymer has the trade name Bionolle. Its processability is similar to that of conventional resins, such as PE (Puchalskiet al., 2018). Bionolle can be processed into films, which can be used for agricultural purposes, shopping bags, compost bags etc. Showa Highpolymer has produced a blend of Bionolle and starch that has properties similar to homogeneous Bionolle and eco-friendly, too (Fujimaki, 1998; Ichikawa and Mizukoshi, 2011; Showa Denko Europe, 2018).

3.2.3 Biopolyethylene PE is probably the most commonly used plastic. It is called polythene in everyday use. PE is an important engineering polymer produced from fossil resources. Its ease of fabrication and chemical resistance properties make it popular in the chemical industries (Babu et al., 2013). “Its molecular structure provides the key to its versatility.” Polyethylene is produced by combination of single carbon atoms to form long chains of carbon atoms. These long chains are termed macromolecules. Attached to each carbon atom are usually two hydrogen atoms. Fig. 3.18 presents the arrangement of macromolecule of polyethylene. The use of PE is mainly for packaging, and it is widely used in plastic bags, plastic films, and plastic bottles. Its annual production is over 60 million tons. PE is a member of a family of materials called polymers, which derives from the Greek word meaning “many parts.” It has long chains of repeating molecular units, which gives the material its strength and also some other desirable properties. PE is available in several grades: • high-density polyethylene (HDPE) • linear low-density polyethylene (LLDPE) • low-density polyethylene (LDPE)

Properties of biobased packaging material

Figure 3.18 Structure of PHAs with respect to classification. (Reproduced with permission from, Raza, Z.A., Abid, S., Banat, I.M., 2018. Polyhydroxyalkanoates: characteristics, production, recent developments 1035 and applications. Int. Biodeterior. Biodegrad. 126, 45e56. https://doi.org/10.1016/j.ibiod. 2017.10.001.)

PE is not biodegradable. This leads to environmental problems associated with its use. Recycling of PE is straightforward, although it would be considered to be environmentally beneficial to use a biodegradable alternative. The basic monomer of the polymer polyethylene is ethylene. Ethanol, which is a similar to ethylene, can be produced by the fermentation of corn or sugarcanedtherefore, the expression biopolyethylene (bio-PE). It is chemically and physically similar to traditional polyethylene. It does not biodegrade but can be recycled. Low-density polyethylene is produced by a process of addition polymerization. With the increase in oil prices, bio-PE is produced by dehydration of ethanol produced by fermentation. The production of PE from bioethanol is not new. Braskem, a Brazilian petrochemical company, made bio-PE and bio-PVC from bioethanol in the 1980s (Babu et al., 2013). But the low prices of oil and the limitations of the biotechnological processes made the technology unappealing at that time (de Guzman, 2010). Bio-PE is currently being produced on a commercial scale from bioethanol produced from sugarcane. Other feedstocks, such as sugar beet, starch crops like maize, wood, wheat, corn, and other plant wastes through fermentation processes can be also used to produce bioethanol. The extracted sugarcane juice containing high sucrose content is fermented in an anaerobic process for producing ethanol. After the completion of the fermentation, ethanol is distilled to remove water and to yield azeotropic mixture of hydrous ethanol. Ethanol is dehydrated at high temperatures using a solid catalyst for producing ethylene and then polyethylene (Guangwen et al., 2007; Luiz et al., 2010). The properties of biobased PE are similar to petrochemical polyethylene. The largest producer of bio-PE is Braskem, with 52% market share. This is the first certified bio-PE in the world. Braskem has an annual production capacity of 200 kton of polyethylene made from sugarcane ethanol. Since 2010, Braskem has been producing the green polyethylene. The term “green” is used to show that the ethylene used as raw material to synthesize the green polyethylene is obtained from sugarcane. According to Braskem, for every ton of green polyethylene produced, 2.5 tons of carbon dioxide are captured from the atmosphere and this remains sequestered for the plastic’s entire life cycle. During its

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combustion, the carbon dioxide released to the atmosphere will be captured again by the sugarcane in the next harvest, thus maintaining the balance of carbon dioxide in the nature. Besides being an environmentally friendly material, bio-PE presents the similar technical properties and processability of the resin made from fossil sources. Therefore, processing the green plastic does not need any technical adjustments or new investments in equipment (Brito et al., 2012). “Braskem is also developing other bio-based polymers such as bio-polyvinyl chloride, bio-polypropylene, and their copolymers with similar industrial technologies. The existing bio-based PE grades are mainly targeted towards food packaging, cosmetics, personal care, automotive parts, and toys. Dow Chemical Company in United States in cooperation with Crystalsev is the second largest producer of bio-PE with 12 percent market share. Solvay is another big producer of bio-PE, having 10 percent market share and is a leader in the production of bio-PVC with similar technologies. In China, China Petrochemical Corporation has set up production facilities for producing bio-PE from bio derived ethanol”(paperity.org; Haung et al., 2008). Bio-PE can replace fossil fuelebased PE. Bio-PE is being used in different fields, in packaging, engineering, agriculture, and several commodity applications due to its low price and excellent performance (Vona et al., 1965; Aamer et al., 2008 Kasirajan and Ngouajio, 2012). Typical applications of bio-PE are blow-molded hollow parts such as beverage containers, injection-molded parts, automotive fuel tanks, tubes, films (storage bags, pouches, packaging films), and other applications where bio-PE could be an environmentally friendly drop-in replacement. Bio-PE is a drop-in equivalent for fossil fuelebased PE having an identical chemical structure, applications, and recycling. The drop-in compatibility and ability to be recycled using established recycle streams makes implementation of bio-PE very easy. The price of bio-PE is about 50% higher as compared to fossil-fuel PE, but as the production volumes increase, the price would decrease. The use of sugarcane as a substrate for biopolyethylene production has several advantages. By reducing petroleum use, environmental damage is reduced. Moreover, sugarcane captures a large amount of carbon dioxide during growth. By the time the biopolyethylene is produced, a net reduction of carbon dioxide is obtained. More than 1.5 billion pounds of carbon dioxide per year are consumed by the process. Biopolyethylene is produced from ethanol. The ethanol is produced from sugarcane fermentation. Once it is produced, it is processed to remove the alcohol group. The dehydration process produces ethylene, which is then polymerized into chains to form polyethylene.

3.2.4 Polyhydroxyalkanoates Polyhydroxyalkanoates (PHAs) are the most well-known biopolymers. These are polyesters of hydroxyalkanoates (HAs) synthesized as carbon and energy storage compounds

Properties of biobased packaging material

by numerous bacteria (Raza et al., 2018; Mozejko-Ciesielska and Kiewisz, 2016; Rydz et al., 2015). They were observed in 1888 by Beijerincka for the first time. But, he could not define their role and composition. In 1926, French researchers obtained the poly-3hydroxybutyric acid from Bacillus megaterium (Lemoigne, 1923). In 1958, Macrae and Wilkinson were able to prove that PHAs in bacterial cells play the role as the reserved materials of carbon and energy, and they are collected only in an increased carbon-to-nitrogen ratio. In the beginning of 1959, several companies were set up to manufacture PHAs fully independent from petroleum sources (Mozejko-Ciesielska and Kiewisz, 2016). Commercial processes for PHA production were initially developed by W. R. Grace and company. But, low efficiency and problems with PHA’s purification forced the company to stop producing it. In the beginning of the 1980s, PHAs were produced under the trade names of BiopolTM, NodaxTM, BiocycleTM, BiomerTM, and BioGreenTM. The PHA market is currently very small. Telles was established as a joint venture between Metabolix and Archer Daniels Midland in July 2006, aimed at larger capacity, but hardly sold any PHAs and was closed in 2012. PHA producers are seeing potential in this biomaterial, claiming that PHAs are a new generation of biopolymers and their market needs time to develop. Demand for PHAs is expected to grow 10fold by 2020 (Aeschelmann and Carus, 2015). PHAs are a class of linear polyesters containing hydroxy acid monomers (HAs) joined together by an ester bond (Fig. 3.19). This bond is formed by connecting the carboxylic group of a monomer with the hydroxyl group of a neighboring one (Philip et al., 2007). Depending on the number of carbon atoms in the monomers, PHAs are classified mainly into two groups: scl-PHAs (short-chain-length PHAs) and mcl-PHAs (medium-chain-length PHAs. Scl-PHAs contain 3e5 carbon atoms and are synthesized by several bacteria such as Cupriavidus necator. Mcl-PHAs contain monomers having 6e14 carbon atoms and are synthesized mainly by Pseudomonas species. Furthermore, bacteria are able to produce copolymers when mixed substrates are used. The bacteria convert the carbon sources into scl-copolymers, e.g., poly(3-hydroxybutyrate-co-3-hydroxyvalerate or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and mcl-copolymers, e.g., poly (3-hydroxyhexanoate-co-3hydroxyoctanoate). There are also scl-mcl-copolymers which consists of scl- and mcl-monomers e.g. poly(3hydroxybutyrate-co-3-hydroxyhexanoate). When carbon sources are alternated overtime during bacterial fermentation process, microorganisms synthesize PHAs block copolymers. The structural composition of PHAs polymers depends on the carbon source and the bacterial culture used. The

Figure 3.19 PE macromolecule carbon chain.

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side chain can be saturated or not, and can possess branched, aromatic, halogenated, and even epoxidized monomers. PHAs polymers composed of a bromide and aromatic group were extracted from Pseudomonas putida. Chemical modifications of the PHAs side chains can be used for introducing the functional group into natural PHAs affecting the material properties of the polymers to a great extent. (Mozejko-Ciesielska and Kiewisz, 2016; Pederson et al., 2006; Fritzsche et al.,1990; Hartmann et al., 2006)

There are two main categories of PHAs: PHB and PHV. The most commonly marketed PHAs are copolymers of PHB and PHV combined with plasticizers and inorganic additives. Although significantly more expensive than polymers ultimately based on mineral oil, there may be opportunities for the reduction of costs through the potential usage of inexpensive raw materials such as molasses. Natural PHAs are attracting attention in several fields such as packaging industry, medicine, surgery, pharmacology, agriculture, biotechnology, waste management, etc. (Rydz et al., 2015; Philip et al., 2007). Synthetic PHAs show greater benefits over natural polymers because they can be tailored to give a wide range of properties and to obtain tailor-made biodegradable material for specific applications in different areas (Rydz et al., 2015; Nair and Laurencin, 2007; Middleton and Tipton, 2000) PHAs are also produced by transgenic microorganisms and plants (Anderson and Dawes, 1990; Gomez et al., 2012; Steinb€ uchel et al., 1994). Plant cells are able to produce only a small amount of PHA. In bacteria, PHAs can accumulate at 90% of the dry cell weight. Bacterial fermentation of PHAs utilizes sugar and fatty acids as carbon and energy sources (Verlinden et al., 2007). These agricultural feeds are processed directly by enzymes to the polymer under balanced growth conditions when the cells become limited for an essential nutrient but are exposed to an excess of carbon (Khemani and Scholz, 2012; Doi, 1990). Three types of natural PHB with different numbers of HB and different functions have been identified in living organisms (Rydz et al., 2015; (Doi, 1990; Lenz and Marchessault, 2005; Reusch et al., 2003; Dedkova and Blatter, 2014).

1. high-molar-mass storage PHB in cytosolic inclusion bodies of various microorganisms, consisting of 10,000 to >1,000,000 HB residues 2. low-molar-mass PHB in cell membranes (complexed with polyphosphates) consisting of 100e300 residues; and 3. short-chain oligo[(R,S)-3-hydroxybutyrate] (OHB) (30 HB units) covalently conjugated to proteins, found even in human tissues (ncsu.edu). There are many microorganisms which accumulate PHB (Gabor and Tita, 2012) but the most widely studied bacterium is Ralstonia eutropha, due to its ability to accumulate large quantities of PHB (Khanna and Srivastava, 2005; Trainer and Charles, 2006; Sanchez-Garcia et al., 2010; Vieira et al., 2011; Yalcin et al., 2006). Other microorganisms that accumulate PHB are: Haloferax mediterranei, Halomonas boliviensis, Bacillus megaterium. (www.biocomposites.bangor.ac.uk; Quillaguam an et al., 2006; Tian et al., 2011; Li et al., 2011)

Properties of biobased packaging material

PHB is a linear, isotactic, semicrystalline biopolymer based on (R)-3-hydroxybutyric acid and has relatively high glass transition and melting temperatures. These are not good features for packaging applications. For improving the flexibility, PHB is synthesized with various co-polymers such as poly-(3-hydroxyvalerate) (HV) leading to a decrease of the glass transitions and melting temperatures (Spitalský et al., 2006; Modi et al., 2011). Current applications of PHB-based polymers or composites include the packaging industry, medicine, pharmacy, agriculture, food industry. (www.biocomposites.bangor.ac.uk; Valappil et al., 2007) The physical properties of PHAs vary from crystalline-brittle to soft-sticky materials depending on the length of the side aliphatic chain on beta-carbon. The high crystallinity of PHB limits their applications in packaging. The melting point ranges from 173 to 180 C and the Tg is around 5 to 5 C (Gao et al., 2011; Kunasundari and Sudesh, 2011; Rydz et al., 2015). For most practical applications, the polymer is too brittle and materials obtained there from possess poor mechanical properties. PHB can be copolymerised with the structural segments derived from selected natural PHAs for reducing the crystallinity and improving the properties. (ncsu.edu). Copolymerisation of PHB with HV at a dose level of 5e20 percent allows the production of PHBV copolymer with better mechanical properties. Such material can be used as biodegradable packaging. Functional PHAs can be produced using biosynthetic methods by using several functional monomers or other metabolites in the polymer sequence. Fermentation of Alcaligenes eutrophus in a medium containing polyethylene glycol or polysaccharide produces a hydroxyterminated block copolymer containing PHA. (www.omicsonline.org; Modi et al., 2011; Shi et al., 1996; Shi et al., 1996)

PHA[s] have material properties similar to thermoplastics and elastomers so they are attractive substitutes for petrochemical plastics (Choi and Lee, 1998). This property of PHA, acting as an ideal storage compound, is due to its insolubility inside bacterial cytoplasm, which exerts slight increase in osmotic pressure. Besides serving as storage compounds of carbon and energy sources, PHA also acts as sink for reducing equivalents for some microorganisms. Bacteria containing PHA storage materials would be able to survive during starvation period compared to those without PHA, as this energy-reserve material slows down the cell autolysis and its mortality rate (Anderson and Dawes, 1990). PHAs are composed of R()-3-hydroxyalkanoic acid monomers ranging from C3 to C14 carbon atoms with variety of saturated or unsaturated and straight or branched chain containing aliphatic or aromatic side groups. The molecular weight of PHA depends on the microorganism and growth conditions which may range between 2  105 to 3  106 daltons. This property of PHA production, to incorporate monomers of different length makes it possible to be used in wide range field of applications. Intracellular depolymerase enzymes degrade these PHA to carbon and energy source, when the supply of the limiting nutrient is restored. (Varsha and Savitha, 2011)

“PHAs are found in several organisms, but microorganisms can be used to tailor their production in cells. A process to produce PHA by bacterial fermentation involves fermentation, isolation, and purification from fermentation broth” (Babu et al., 2013). The fermentation vessel is filled with medium and inoculated with bacteria. The substrates include organic waste, cellulosics, vegetable oils, municipal solid waste, and fatty acids depending on the specific PHA required. The carbon source is fed into the vessel until it is used and cell growth and PHA accumulation is complete. A minimum of 48 h is

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required for fermentation time. For isolating and purifying PHA, cells are concentrated, dried, and extracted with solvents. The residual cells are removed from the solvent containing dissolved PHA by solid-liquid separation process. The PHA is precipitated by adding alcohol and recovered by precipitation (Kathiraser et al., 2007). More than 150 PHA monomers have been identified as the constituents of PHAs (Steinb€ uchel and Valentin, 1995). This diversity allows the production of biopolymers having different properties, tailored for specific applications. Poly-3-hydroxybutyrate was the first bacterial PHA identified and has received substantial attention. Its thermal and mechanical properties are similar to those of polystyrene and polypropylene (Savenkova et al., 2000). It shows slow crystallization, narrow processing temperature range, and tendency to “creep,” so it is not suitable for several applications. Development work is therefore required to solve these problems (Reis et al., 2008). Several companies have developed PHA copolymers with typically 80%e95% (R)-3-hydroxybutyric acid monomer and 5%e20% of a second monomer for improving the properties of PHAs. The copolymer poly(3HB-co-3HV) has a much lower crystallinity, reduced stiffness and brittleness, higher melt viscosity, and increased tensile strength and toughness compared to poly (3HB) while remaining biodegradable. Higher melt viscosity is a desirable property for extrusion and blow molding (Hanggi, 1995). Tianan Biologic Material Co. in China is a biopolymer specialist, focused on the production and application development of PHB and PHB copolymers. Tianan’s PHBV contains about 5% valerate, which is used for improving the flexibility of the polymer. Tainjin Green Biosciences, China, invested jointly with DSM to build a production plant with 10-kton/year capacity for producing PHAs (DSM press release 2008). The global producers of PHAs-based polymers are presented in Table 3.12 (Doug, 2010; Ravenstijn, 2010). PHA polymers are thermoplastic, and their properties depend on their composition. The melting temperatures range from 50 to 180 C, and Tg of the polymers varies from 40 to 5 C (McChalicher and Srienc, 2007). “Material properties of PHB are similar to polypropylene, and shows a good resistance to moisture and aroma barrier properties. Polyhydroxybutyric acid synthesized from pure PHB is relatively brittle and stiff. PHB copolymers, which may include other fatty acids such as betahydroxyvaleric acid, may be elastic (McChalicher and Srienc, 2007). PHAs can be processed in existing polymer-processing plant and can be converted into injection-molded components: film and sheet, fibers, laminate, and coated articles, nonwoven fabrics, feminine hygiene products, synthetic paper products, disposable items, adhesives, waxes, paints, binders, and foams. Metabolix (Cambridge, MA) has received FDA clearance for use of PHAs in food contact applications. These materials are suitable for food packaging applications including caps and closures, disposable items such as forks, spoons, knives, tubs, trays, and hot cup lids, and products such as housewares, cosmetics, and medical packaging (Philip et al., 2007). PHA and its copolymers are widely used as biomedical implant materials” (paperity.org).

Properties of biobased packaging material

Table 3.12 Global suppliers of various types of PHAs.

Bio-on, Italy Kaneka, Singapore Meredian, USA Metabolix, USA Mitsubishi Gas Chemicals, Japan PHB Industrial S/A, Brazil Shenzen O’Bioer, China Tepha, USA Tianan Biological Materials, China Tianjin Green Biosciences, China Tianjin Northern Food, China Yikeman Shandong, China Based on Doug, S. 2010 Bioplastics: Technologies and Global Markets. BCC research reports PLS050A. http://www.bccresearch.com/report/bioplastics-technologiesmarkets- pls050a. htm, Ravenstijn, J.T.J., 2010. The State-Of-The Art on Bioplastics: Products, Markets, Trends and Technologies. Polymedia, L€ udenscheid.

Various applications of PHA and their polymer blends are reported (Yang et al., 2002; Chen and Qiong, 2005; Bayram and Denbas, 2008; Tang et al., 2008; Clarinval and Halleux, 2005; Sodian et al., 2000; Wang et al., 2003; de Roo et al., 2002; Zhao et al., 2003; Ruth et al., 2007; T€ uresin et al., 2001; Williams et al., 1999; Chen et al., 2008; Freier et al., 2002; Kunze et al., 2006; Volova et al., 2003; Philip et al., 2007; Amass et al., 1998; Walle et al., 2001). “These include sutures, suture fasteners, meniscus repair devices, rivets, bone plates, surgical mesh, repair patches, cardiovascular patches, tissue repair patches, and stem cell growth. By changing the PHA composition, the manufacturer is able to adjust the properties such as biocompatibility and polymer degradation time within desirable time frames” (Babu et al., 2013). PHAs can also be used in drug delivery due to their controlled degradability and biocompatibility. Only a few PHAs have been studied for this type of application, and it remains an important area for exploitation (Tang et al., 2008).

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Tomasula, P.M., 2009. Using dairy ingredients to produce edible films and biodegradable packaging materials. In: Corredig, M. (Ed.), Dairy-Derived Ingredients: Food and Nutraceutical Uses. CRC Press, Boca Raton, FL, USA, pp. 589e624. Tomasula, P.M., Yee, W.C., Parris, N., 2003. Oxygen permeability of films made from CO2-precipitated casein and modified casein. J. Agric. Food Chem. 51, 634e639. Trainer, M.A., Charles, T.C., 2006. The role of PHB metabolism in the symbiosisof rhizobia with legumes. Applied Microbiology and Biotechnology 71 (4), 377e386. Trilsbach, G.F., Pielken, P., Hamacher, K., Sahm, H., 1984. Xanthan formation by Xanthomonas campestris under different culture conditions. In: 3rd European Congress of Biotechnology. Verlag Chemie, Weinheim, pp. 65e70. Tullo, A., 2000. Plastic found at the end maize. Chemical & Engineering News 78 (3), 13. https://doi.org/ 10.1021/cen-v078n003.p013. T€ uresin, F., G€ ursel, I., Hasirci, V., 2001. Biodegradable polyhydroxyalkanoate implants for osteomyelitis therapy: in vitro antibiotic release. J Biomaterials Sci 12 (2), 195e207. Polymer Edition. U.S. Congress, Office of Technology Assessment, 1993. Biopolymers: Making Materials Nature’s WayBackground Paper. U.S. Government Printing Office, Washington, DC. OTA-BP-E-102. Valappil, S.P., Misra, S.K., Boccaccini, A.R., Keshavarz, T., Bucke, C., Roy, I., 2007. Large-scale production and efficient recovery of PHB with desirable material properties, from the newly characterised Bacillus cereus SPV. Journal of biotechnology 132 (3), 251e258. Valerie, D., Vinod, D.V., 1998. Pharmaceutical applications of chitosan. Pharmaceut. Sci. Technol. Today 1, 246e253. van de Velde, F., De Ruiter, C.A., 2002. Carrageenan. In: Steinb^ uchel, A., DeBaets, S., VarrDamme, E. i. (Eds.), Biopolymers, vol. 6. Varsha, Y.M., Savitha, R., 2011. Overview on Polyhydroxyalkanoates: A Promising Biopol. J. Microbial. Biochem. Technol. 3, 099e105. https://doi.org/10.4172/1948-5948.1000059. Vartiainen, J., Motion, R., Kulonen, H., R€att€ o, M., Skytt€a, E., Ahvenainen, R., 2004. Chitosan-coated paper: effects of nisin and different acids on the antimicrobial activity. J. Appl. Polym. Sci. 94, 986e993. Velde, K.V.D., Kiekens, P., 2001. Thermoplastic polymers: overview of several properties and their consequences in flax fibre reinforced composites. Polym. Test. 21, 433e442, 2001. Verlinden, R.A.J., Hill, D.J., Kenward, M.A., Williams, C.D., Radecka, I., 2007. Bacterial synthesis of biodegradable polyhydroxyalkanoates. J. Appl. Microbiol. 102, 1437e1449. Vieira, M.G.A., da Silva, M.A., dos Santos, L.O., Beppu, M.M., 2011. Natural-based plasticizers and biopolymer films: a review. Eur. Polym. J. 47, 254e263. Virginia, E., Marie, G., Eric, P., Luc, A., 2011. Structure and properties of glycerol plasticized chitosan obtained by mechanical kneading. Carbohydr. Polym. 83, 947e952. Vojdani, F., Whitaker, J.R., 1994. Chemical and enzymatic modification of proteins for improved functionality. In: Hettiarachchy, N.S., Ziegler, F.R. (Eds.), Protein Functionality in Food System. Marcel Dekker, Inc., New York, NY. Volova, T., Shishatskaya, E., Sevastianov, V., Efremov, S., Mogilnaya, O., 2003. Results of biomedical investigations of PHB and PHB/PHV fibers. Biochem. Eng. J. 16, 125, 1. Vona, I.A., Costanza, J.R., Cantor, H.A., Robert, W.J., 1965. Manufacture of Plastics, vol. 1. Wiley, New York, pp. 141e142. Voragen, A.G., Pilnik, W., 1995. Pectins. In: Stephen, A.M. (Ed.), Food Polysaccharides and Their Applications. Marcel Dekker, Inc., New York, NY, USA, pp. 287e340. Vroman, I., Tighzert, L., 2009. Biodegradable polymers. Materials 2 (2), 307e344. Walle, G.A.M., de Koning, G.J.M., Weusthuis, R.A., Eggink, G., 2001. Properties, modifications and applications of biopolyesters. Adv. Biochem. Eng. Biotechnol. 71, 264e291. Wang, Z., Itoh, Y., Hosaka, Y., Kobayashi, I., Nakano, Y., Maeda, I., Umeda, F., Yamakawa, J., Kawase, M., Yagi, K., 2003. Novel transdermal drug delivery system with polyhydroxyalkanoate and starburst polyamidoamine dendrimer. J. Biosci. Bioeng. 95 (5), 541e543. Wang, Y., Xiong, Y.L., Rentfrow, K.G., Newman, M.C., 2013. Oxidation promotes cross-linking but impairs film-forming properties of whey proteins. J. Food Eng. 115 (1), 11e19.

Properties of biobased packaging material

Weber, C. (Ed.), 2000. Biobased Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0. Weraporn, P.A., Sorapong, P., Narongchai, O.C., Ubon, I., Puritud, J., Sommai, P.A., 2011. Preparation of polymer blends between poly (L-lactic acid), poly (butylenes succinate-co-adipate) and poly (butylene adipate-co-terephthalate) for blown film industrial application. Energy Procedia 9, 581e588. Whistler, R.L., Daniel, J.R., 2005. Starch. In: Seidel, A. (Ed.), Kirk Othmer Encyclopedia of Chemical Technology, fifth ed., vol. 22. John Wiley & Sons, Inc., Hoboken, USA. Wihodo, M., Moraru, C.I., 2015. Effect of Pulsed Light treatment on the functional properties of casein films. LWT e Food Sci. Technol. 64, 837e844. Williams, S.F., Martin, D.P., Horowitz, D.M., Peoples, O.P., 1999. PHA applications: addressing the price performance issue I. Tissue engineering. Int. J. Biol. Macromol. 25, 111e121. Win, N.N., Stevens, W.F., 2001. Shrimp chitin as substrate for fungal chitin deacetylase. Appl. Microbiol. Biotechnol. 57, 334e341. Wurzburg, O.B., 1986. Introduction. In: Modified Starches: Properties and Uses. CRC Press, Inc., Boca Raton, USA, pp. 253e263. Xiaoqun, Mo, Xiuzhi, S., 2002. Plasticization of soy protein polymer by polyol-based plasticizers. J. Am. Oil Chem. Soc. 79, 197. https://doi.org/10.1007/s11746-002-0458-x. Xie, Z.P., Huang, Y., Chen, Y.L., Jia, Y., 2001. A new gel casting of ceramics by reaction of sodium alginate and calcium iodate at increased temperature. J. Mater. Sci. Lett. 20, 1255e1257. Yalcin, B., Cakmak, M., Arkin, A.H., Hazer, B., Erman, B., 2006. Control of optical anisotropy at large deformations in PMMA/chlorinated-PHB (PHB-Cl) blends: Mechano-optical behavior. Polymer 47 (24), 8183e8193. Yan, Y.F., Krishnaiah, D., Rajin, M., Bono, A., 2009. Cellulose extraction from palm kernel cake using liquid phase oxidation. J. Eng. Sci. Technol. 4, 57e68. Yang, L., Chen, X., Jing, X., 2008. Stabilization of poly(lactic acid) by polycarbodiimide. Polym. Degrad. Stabil. 93, 1923e1929. Yang, H., Guo, X., Chen, X., Shu, Z., 2014. Preparation and characterization of collagen food packaging film. J. Chem. Pharmaceut. Res. 6 (6), 740e745. Yang, F., Li, X., Li, G., Zhao, N., Zhang, X., 2002. Study on chitosan and PHBHHx used as nerve regeneration conduit material. J. Biomed. Eng. 19, 25e29. Yew, G.H., Mohd Yusof, A.M., Mohd Ishak, Z.A., Ishiaku, U.S., 2005. Water absorption and enzymatic degradation of poly(lactic acid)/rice starch composites. Polym. Degrad. Stabil. 90 (3), 488e500. Zajic, J.E., LeDuy, A., 1973. Flocculant and chemical properties of a polysaccharide from Pullularia pullulans. Appl. Microbiol. 25, 628e635. Zekovic, D.B., Kwiatkowski, S., Vrvic, M.M., Jakovljevic, D., Moran, C.A., 2005. Natural and modified (1/3)-beta-D-glucans in health promotion and disease alleviation. Crit. Rev. Biotechnol. 25, 205e230. Zhang, J.F., Sun, X.Z., 2004. Mechanical properties of PLA/starch composites compatibilized by maleic anhydride. Biomacromolecules 5, 1446e1451. Zhao, P., Liu, W., Wu, Q., Ren, J., 2010. Preparation, mechanical, and thermal properties of biodegradable polyesters/poly(lactic acid) blends. J. Nanomater. 2010, 1e8. Zhao, K., Tian, G., Zheng, Z., Chen, J.C., Chen, G.Q., 2003. Production of D-()-3- hydroxyalkanoic acid by recombinant Escherichia coli. FEMS Microbiol. Lett. 218, 59e64. Zhao, R.X., Torley, P., Halley, P.J., 2008. Emerging biodegradable materials: starch-and protein-based bionanocomposites. J. Mater. Sci. 43, 3058e3071. Zhong, Z., Sun, X.S., 2001. Properties of soy protein isolate/polycaprolactone blends compatalized by methylene diphenyl diisocyanate. Polymer 42, 6961e6969. Zhu, F., Du, B., Xu, B., 2016. A critical review on production and industrial applications of betaeglucans. Food Hydrocoll. 52, 275e288.

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Further reading Alginate Market Size Worth $923.8 Million By 2025 j CAGR: 4.5% [online] https://www. grandviewresearch.com/press-release/global-alginate-market. Angellier-Coussy, H., Gastaldi, E., Gontard, N., Guillard, V., 2011. Influence of processing temperature on the water vapour transport properties of wheat gluten based agromaterials. Ind. Crops Prod. 33 (2), 457e461. Bauer, R., 1938. Physiology of dematium pullulans de Bary. Zentralbl Bacteriol Parasitenkd Infektionskr Hyg Abt2 98, 133e167. Beijerinck, M.W., 1888. Die bacterien der Papilionaceen-kn€ ollchen. Botanische Zeitung 46, 725e735, 741e750, 757e771, 781e790, 797e804. IMARC, 2018. Casein Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast 2018-2023. https://www.imarcgroup.com/casein-market. Munoz-Bonilla, A., Marcelo, G., Casado, C., Teran, F.J., Fernandez-Garcia, M., 2012. Preparation of glycopolymer-coated magnetite nanoparticles for hyperthermia treatment. J. Polym. Sci. Part A Polym. Chem. 50, 5087. Payen, A., 1842. ‘Troisieme memoire sur le development vegetaux’Extrait des memoires de l’Academie  ntranges. Imprimerie Royale, Paris. Royale des Sciences: Tomes III des Savants E PolysacImeson, A., 2000. Carrageenan. In: W, P., Phillips, G.O. (Eds.), Handbook of Hydrocolloids. CRC Press, Boca Raton, pp. 87e102. Rein, D.M., Khalfin, R., Cohen, Y., 2012. Cellulose as a novel amphiphilic coating for oil-in-water and water-in-oil dispersions. J. Colloid Interface Sci. 386 (1), 456e463. Ridley, B., O’Neill, M.A., Mohnen, D., 2001. Pectins: structure, biosynthesis and oligogalacturoniderelated signalling. Phytochemistry 57, 929e967. Schofield, J.D., Bottomley, R.C., Timms, M.F., Booth, M.R., 1983. The effect of heat on wheat gluten and the involvement of sulphydryl-disulphide interchange reactions. J. Cereal. Sci. 1 (4), 241e253. Shukla, R., Munir, C., 2001. Zein industrial protein from corn. Ind. Crops Prod. 13, 171e192, 2001. Sodian, R., Sperling, J.S., Martin, D.P., 1999. Tissue engineering of a trileaflet heart valve-early in vitro experiences with a combined polymer. Tissue Eng. 5, 489e494. Stylianou, A., Yova, D., Alexandratou, E., Petri, A., 2013. Atomic force imaging microscopy investigation of the interaction of ultraviolet radiation with collagen thin films. In: Proc. SPIE 8594, Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications X, 85940E. https://doi.org/10.1117/12.2002460, 19 February 2013. Swatloski, R., Holbrey, J., Spear, S., Rogers, R., 2002. Cellulosic pulps, fibres and materials. Electrochem. Soc. Proc. 19, 155. Teli, M.D., Chiplunkar, V., 1986. Role of thickeners in final performance of reactive prints. Text. Dyer Print. 19, 13e19. Yu, L., Dean, K., Li, L., 2006. Polymer blends and composites from renewable resources. Prog. Polym. Sci. 31 (6), 576e602.

Relevant websites dspace.lboro.ac.uk. faculty.fshn.illinois.edu/wmcheryan/avcpro.htm. http://www.bccresearch.com/report/bioplastics-technologiesmarkets- pls050a.htm. http://www.succinity.com/images/succinity_broschure.pdf. https://factsweek.com/410,160/global-industrial-gelatin-market-2018-review. https://newatlas.com/casein-milk-packaging/45005/. http://polymerdatabase.com/polymer%20classes/Cellulose%20type.html. https://www.asdreports.com. https://www.dextran.com/aboutdextran/dextran-chemistry/dextran-structure. https://www.fooddive.com/.../20171010-global-gelatin-market-2017-top-key-players. https://www.grandviewresearch.com/industry-analysis/gellan-gum-market. https://www.usda.gov/oce/commodity/wasde/latest.pdf.

Properties of biobased packaging material

ijrrpas.com. literatur.ti.bund.de. mdpi.com. miller-klein.com/wp-content/uploads/2016/12/2007LandscapeforBiopolymers.pdf. monotonecritic.com/2018/02/08/global-carrageenan-market-2017-shemberg-fmc-ceamsa-daniscogelymar-karagenindonesia-cp-kelco-isi-cargill-tbk/. ncsu.edu. paperity.org. repositorio-aberto.up.pt. revistapolimeros.org.br. saiapm.ulbsibiu.ro. shorterijrrpas.com. www.aaccnet.org. www.abnewswire.com/.../global-gelatin-market-catalysedby-flourishing-food-industr. www.bc.bangor.ac.uk. www.biocomposites.bangor.ac.uk. www.biomasspackaging.com/the-pros-and-cons-of-polylactic-acid-pla-bioplastic-the-. www.fas.org. www.grandviewresearch.com/industry-analysis/cellulosederivatives-market. www.imarcgroup.com/casein-market. www.lucidgroup.com. www.millioninsights.com. www.mordorintelligence.com/industry.../global-carrageenan-market-industry. www.omicsonline.org. www.prairiefarmer.com. www.princeton.edu. www.progressbiomaterials.com. www.succinity.com/images/succinity_broschure.pdf. www.wiley-vch.de. www1.lsbu.ac.uk.

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CHAPTER 4

Packaging types Contents 4.1 Rigid packaging 4.2 Flexible and films packaging References Relevant websites

113 117 127 127

4.1 Rigid packaging Rigid packaging material can be used in any type of packaging related application (Table 4.1). Rigid packaging is a robust form of packaging and is able to attach substantial amount of load and insulate a reactive product from the external environment without polluting the product. Rigid packaging is used for packing volatile and highly reactive products along with other types of products. The final product can be without printing, feature high-performance graphics, or feature one or more color-printing schemes. Rigid packaging is usually sealed with adhesives, staples, or tape. Rigid packaging has existed for many decades and is continuing to evolve to meet the needs of a changing consumer landscape (Gange, 2010). Materials used for manufacturing rigid packaging can be reused and recycled and contribute to more than 60% of the rigid packaging market. Rigid plastic packaging includes products such as trays, lids, disposable and reusable cups, clamshells, containers, bottles, jars, tubs, pots, cans, canisters, caps and closures, and pails and buckets (Fig. 4.1).

Table 4.1 Rigid packaging. Material

Plastic, metal, glass, wood, and paper and paperboard Product

Trays, boxes, containers and cans, and bottle and jars Application

Food and beverages, chemical and petrochemical industry, consumer goods, and health care and pharmaceuticals

Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00004-7

© 2019 Elsevier Inc. All rights reserved.

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Figure 4.1 Rigid packaging. (http://www.adhesives.org/docs/default-document-library/rigid_versus_flexible_ pkg_july2010.pdf. www.packaging.basf.com/p02/Packaging/en/content/%85/starre_kunststoffverpackunge %85.)

All substrates used in rigid plastic packaging are able to resist transport, handling, abuse, storage, temperature ranges, varying degrees of shelf life, climatic conditions and protect the contents stored in them. In addition to this, they may also be required to meet various other demands, such as being chemically neutral, or able to tolerate freezer, oven, and microwave temperatures. The rapid development in the area of rigid plastics in packaging is affected by the development of plastic raw materials and the conversion processes. Low- and highdensity polyethylene (PE), polystyrene (PS), polypropylene (PP), and polyvinyl chloride (PVC) are being used in rigid packaging as blow molding, injection molding, and thermoforming processes to mold containers from these materials with high speed and efficiency have been developed. Polyester or polyethylene terephthalate (PET) has been used since 1941 as a flexible packaging material. After the commercial development of injection-stretch blow molding process in 1975, the unique properties of PET could be used for meeting the challenges of packaging carbonated drinks in a plastic container. PE and PET are the leading materials used in rigid plastic packaging. Overall PE is the leading polymer, whereas PET leads in applications for bottled water, carbonated soft drinks, and fruit juice. PET gained share by material type in the rigid packaging sector and is forecast to become the leading rigid plastic container resin type in the next few years. Innovations in barrier technology and improved bottle designs have played a major role in the rapid expansion of PET. Other major substrates used are PP, PS, PVC, and expanded polystyrene (EPS). A significant occurrence with respect to biopolymers in the rigid packaging sector was the development of bio-PE by Braskem. Braskem and Dow Chemical Company have a

Packaging types

combined bio-PE supply capacity of over half a million tons per year, which will enable biopolymers to increase their share of the rigid packaging sector by material type. In other developments, Plantic Technologies Ltd., a world-leading innovator in bioplastics, which manufactures the thermoplastic (TPS) starch-based Plantic range of rigid biopolymer for packaging, integrated a new shortwave infrared (IR) system in its production in 2010. The system, supplied by Heraeus Noblelight, optimizes the deep drawing of bioplastic confectionery insert trays. The shortwave, high-power IR rapid heating prevents the trays from becoming brittle and has been shown to cut rejection rates. With conventional plastic, the deep drawing involves several heating stages to achieve the deformation temperature. However, the stability, flexibility, and strength of TPS is adversely affected by extended heating times due to water seepage during the process. Plantic and Heraeus considered several ways of optimizing the process and found that shortwave IR emitters were ideal as their high power could reach a deformation temperature of 140 C in 2 s with minimal water loss. In February 2010, Klockner Pentaplast began marketing Plantic biopolymer rigid packaging films in the United States under the Pentafood Biofilm brand. These films are designed for the thermoformed packaging of confectionery, cookies and trays for chocolates. Compostable to ASTM 6400 and EN 13432 standards, Pentafood Biofilms may be used in the manufacture of bi- and tricolor packages in transparent and opaque combinations. Stora Enso has launched a range of packaging application paperboard products coated with biodegradable biopolymer. The products, designed to be used in plates, cups, folding cartons, and trays, comply with the EN13432 and ASTM6400 compostability standards. The Cupforma range provides biodegradable drinking cup options for the majority of end use requirements including hot and cold drinks, yogurt and ice cream, while fresh and chilled foods that are not heated in their packages can be packaged on the company’s Trayforma Performance Bio paperboard trays. Stora Enso’s patented biopolymer-coating technology provides the packaging with the necessary barrier properties, giving protection against humidity, oxygen, taste, light, and odors, thus prolonging shelf life. The coating choice is based on the barrier type sought. Rigid plastics packaging is now dominated by high-density polyethylene (HDPE) and PET. The PET is actively gaining market share on many fronts. Also, there is a lot of development in the area of PP-containing materials. According to market study by Smithers Pira, rigid plastic packaging consumption worldwide was 166 billion US dollars in 2017 and expected to exceed 200 billion US dollars at the end of 2022 (www.smitherspira.com). Volume-wise consumption of rigid plastics was 52.9 million tons in 2017 and will grow at an annual rate of 3.7% to 63.4 million tons in the next 5 years (https://www.smitherspira.com/%85/2017/%85/ what-is-next-for-the-rigid-plastic-packaging).

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Rigid plastic packaging market expansion will continue to profit from the drive to replace traditional materials with lighter weight, more cost-effective and higher performance plastic materials in various markets. This transition is being accelerated by concept innovations e such as the clear plastic can. US-based Milacron has developed The “Klear Can” technology. It is transforming the canned food preservation industry, saving weight and allowing a better display of premium tinned goods on supermarket shelves. (www.smitherspira.com)

The rigid packaging segment is facing many challenges. Sustainable packaging is an important key trend having certain implications for the rigid plastic packaging sector. There is significant pressure for reducing the environmental impact of their packaging. The response has been to address packaging by reducing the use of material without reducing the performance of pack, increasing use of recycled plastic material, and exploring bioplastic packaging. For reducing the environmental impact of packaging, there is a tendency to use more recycled plastic packaging. Biobased plastics are a better choice for brand owners who are showcasing their environmental credentials more clearly. In practice, the different strategies can be combined (www.smitherspira.com). Unilever has announced that all of its plastic packaging will be fully reusable, recyclable, or compostable by 2025. The company has decided to reduce the weight of its packaging by one-third by 2020, and increase the use of recycled plastic content in its packaging to a minimum of 25% by 2025 (www.smitherspira.com). Companies have started to recognize that sustainability in packaging is a core value, rather than a one-off sales and marketing opportunity. Biodegradable packaging for numerous products, including fresh foods, organic and private label brands are available (www.smitherspira.com). Technology is playing a vital role in the development of rigid plastic packaging market because it competes with rival packaging varieties. Many of these directly affect the environmental impact of the pack or product inside. Bio-based plastics, including 100% bio-based PET bottles, are entering the market and will establish substantial market share in the next few years. Lighter plastic packaging also has been developed. Further light weighting of plastic packaging is underway. Improved barrier solutions allow the use of rigid plastic packaging in several food products, reducing emissions during transport (www.smitherspira.com). From a marketing perspective, the further penetration of digital (inkjet and toner) printing systems for beverage bottles and new concepts like no-look and interactive labels are pushing innovation in areas, such as PET carbonated soft drink bottles. (www.smitherspira.com)

Rigid plastic packaging is facing threat from flexible packaging and is now gradually being replaced by flexible packaging. In the developing countries, especially, rigid plastic packaging demand will grow at the highest rates.

Packaging types

Table 4.2 Global rigid plastic packaging consumption.

Asia North America Western Europe Rest of the world Eastern Europe South and Central America

31.4% 22.7% 20.0% 10.3% 7.7% 7.7%

Based on https://www.smitherspira.com/%85/2017/%85/whatis-next-for-the-rigid-plastic-packaging.

The largest consumer of rigid plastic packaging is Asia, which accounted for 31.4% consumption by volume in 2017. The second-largest consumer is North America (22.7%), followed by Western Europe (20.0%). Asia will continue growing at a faster rate, with an annual average growth rate of 5.8% for the next 5 years (Table 4.2). Rigid packaging is used in foods and beverages, consumer goods, health care products and pharmaceuticals, chemical and petrochemical industries, and other industries. The food and beverage industry accounts for more than one-third of the rigid packaging market. China is the largest consumer for soft drinks. It is expected to contribute the largest value share for jars and bottles segment (www.transparencymarketresearch.com). Table 4.3 shows key players for the rigid packaging market.

4.2 Flexible and films packaging The flexible packaging segment is growing fast in the packaging industry (Gange, 2010; Nnamdi, 2003; Coles, 2000). Flexible plastic packaging has no rigid structure of its own, but conforms to the product it protects. Technological developments in flexible plastics have allowed the material to steal market share from paper-based packaging, such as the Table 4.3 Key players for the rigid packaging market.

Amcor Limited Sealed Air Corp. Resilux NV Bemis Company, Inc. Berry Plastic Group, Inc. Reynolds Group Holdings Ltd. GeorgiaePacific LLC, DS Smith Packaging Limited Holmen AB ADR Mondi Group Based on https://www.transparencymarketresearch.com/rigidpackaging-market.html.

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rigid corrugated box. Work on flexible plastics is in progress with new developments in several areas. New plastic products and new applications for existing products are constantly coming to market. While most flexibles are produced from commodity polymers, an increasing number are now being made with sophisticated multilayer structures and combinations of substrates. Packaging in Western Europe is big business, accounting for more than 1% of regional gross domestic product. Plastic is the second most important packaging material in Europe, after paper and board; it is also the most dynamic, with growth based on historic trends estimated at some 4%e5% a year. The flexible component accounts for some 30% of all plastic packaging sales in Western Europe. Under its broadest definition, this includes sales of pallet shrink and stretch wrap, collation shrink, carrier bags, refuse and agricultural sacks, dry cleaning and laundry, industrial liners, heavy-duty sacks, bubble film, mail film, and converted flexible packaging mainly used for consumer products such as food and groceries, DIY, and health care. In 2002, plastic films accounted for some 78% of the flexible packaging materials used in Western Europe (www.smitherspira.com). Table 4.4 shows types of flexible packaging. The flexible packaging sector includes bags, pouches, labels, liners, and wraps, which are used by almost every industry for protecting and preserving its products (Fig. 4.2). Table 4.5 shows the main flexible packaging materials. The five major polymers for flexible plastic packaging are PE, PP, PS, PVC, and PET. PE is commonly used polymer film for packaging because it is inert, permeable to gases, impermeable to water vapor, and inexpensive (Gange, 2010). Flexible plastic packaging has diverse applications in various user industries, such as packaging for food products, pharmaceutical packaging, industrial applications, labels for beverages, overwrap for cigarette packing, lamination of paperboards, and overwrap of textile garments. Flexible plastics packaging benefits from the wide range of polymers available, each with its own combination of physical and chemical properties. These polymers can be used alone or in combination with other polymers or with other materials such as aluminum or cardboard. A broad breakdown of how these materials may be used is presented in Table 4.6. Around the European Union, flexible plastic packaging has been growing rapidly at the expense of other packaging media, such as metal cans, glass bottles, and cartons. Film packages remain a popular choice because of the relatively low cost of materials and production and the wide range of applications for which they can be used. Environmentally, they score well because their low weight helps to conserve resources and many formats may be recycled. Flexible packages are used by the food and beverage industries and also the pharmaceutical and cosmetic industries, on account of the material’s hygienic qualities and the long shelf life that it offers. The development of breathable films, microwaveable and freezer-safe films, and biodegradable films is helping to drive growth within this market. The rise in demand for flexible food packages in developed nations

Packaging types

Table 4.4 Types of flexible packaging. Flexible packaging type 1 Packaging bags

Flexible packaging type 1.1: Paper bag Flexible packaging type 1.2: Nonwoven bags Flexible packaging type 1.3: HM (high molecular) carry bags https://bizongo.in/category/ packaging-bags/plastic-bags/carry-bags Flexible packaging type 1.4: BOPP (biaxially oriented polypropylene) bags Flexible packaging type 1.5: LDPE bags Flexible packaging type 1.6: HDPE bags Flexible packaging type 1.7: PE bags Flexible packaging type 1.8: Biodegradable bags Flexible packaging type 2 Protective packaging

Flexible Flexible Flexible Flexible Flexible

packaging packaging packaging packaging packaging

type type type type type

2.1: 2.2: 2.3: 2.4: 2.5:

Adhesive tapes Courier bags Bubble wrap Air bubble pouches Foam packaging

Flexible packaging type 3 Flexible films

Flexible packaging type 3.1: BOPP (biaxially oriented polypropylene) films Flexible packaging type 3.2: Foil packaging Flexible packaging type 3.3: Stretch films Flexible packaging type 4 Packaging boxes and cartons

Flexible packaging type 4.1: Corrugated roll Flexible packaging type 4.2: Corrugated box Flexible packaging type 5 Pouches

Flexible packaging type 5.1: Ziplock Flexible packaging type 5.2: Stand-up pouches Based on https://warehousebizongo.wordpress.com/2016/10/14/what-types-of-products-are-there-in-flexiblepackaging/.

reflects changing consumer habits and their demand for convenient ready-to-serve meals. Film composites are the established format for consumer packages, especially for food applications, with five-layer films being the standard. Biodegradable and recycled materials are now being incorporated into films, although the approval of grades of recycled PET for repeat use in direct contact with foods still remains an obstacle. Developments in the

119

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Figure 4.2 Flexible packaging. (Based on https://warehousebizongo.wordpress.com/2016/10/14/whattypes-of-products-are-there-in-flexible-packaging/.)

Table 4.5 Main flexible packaging materials.

Polyethylene (PE) Biaxially oriented polypropylene (BOPP) Cast polypropylene (PP) Polyamide (PA) Polyvinyl chloride (PVC) Polyethylene terephthalate (PET) Polystyrene (PS) Cellulose Aluminum foils Papers Based on Nnamdi, A., 2003. Introduction to Flexible Packaging. Pira International Ltd, Surrey.

Table 4.6 Types of flexible plastics. Mono-Material

Shopping bags, candy wraps/twist wraps Polymer Multilayers

Detergent refill packs, PP big bags with PE liners, blood/fluids bags Combined With Other Materials

Metallized film, PE liner in steel drum, bag-in-box packages Based on Nnamdi, A., 2003. Introduction to Flexible Packaging. Pira International Ltd, Surrey.

Packaging types

flexible and films packaging sector with regard to biopolymers include the launch by Clarifoil of a new white ultra-gloss satine lamination film designed for the packaging of luxury confectionery in 2010 (Gange, 2010). The film, which took 2 years to develop and has EN 13432 and ASTM 6400 compostable accreditation, is 90% biodegradable within 6 months and is manufactured from renewable biopolymer derived from wood. It has physical properties similar to Clarifoil’s standard P20 grade cellulose diacetate film, while a bright white finish is achieved with a pure whitening additive and a small quantity of brightening agent. The company developed the film partly in response to a trend in the confectionery sector that is seeing the packaging of premium chocolate move away from black to white. Ultimate Packaging, based in the United Kingdom, launched a new biodegradable printed laminated film in a joint venture with Innovia Films and Sun Chemical. Branded Ultigreen, the film is designed to biodegrade in domestic and industrial compost bins and is suitable for the packaging of a wide range of fresh foods, meats, and nonfood products. “Sun Chemical’s hybrid biodegradable inks are used to reverse print. Innovia’s NatureFlex film is then laminated using a biodegradable adhesive. Alesco, a German company, reported its development of a compostable shrink film designed for use as an outer packaging layer for drinks. The Bioshrink brand film was first made available for wrapping six-packs of 0.5 litre PET and PLA drinks bottles, although the company reported plans to extend the range to include other sizes. The film, tested by the soft drinks bottler SDI, uses a carbon neutral manufacturing process and can optionally be printed with water colours according to a given customer’s requirements “(Gange, 2010). A new shrink-wrap was launched by Mitsubishi Plastics, Inc. in 2009. The film contains more than 50% biomass plastics and is also 10% thinner than conventional labels. The new plastic combines Mitsubishi’s existing Plabio shrink-wrap film with PLA. It has effectively addressed the print and wrinkling problems frequently found with products based on biomass plastic, while a 5 micron reduction in label thickness enables decreased use of raw materials (Gange, 2010). The new plastic material complies with requirements set by the Japanese Biomass Plastic Association of a 50% or more biomass plastic content, so that labels made with it may be given the Biomass Plastic logo. Asahai Soft Drinks was the first large manufacturer in 2009 to use the label, applying it to its Jurokucha brand blended green tea beverage. Ako Kasei, in collaboration with Kyoto University and Hyogo Prefecture Industrial Technology Center, Japan, reported its development of a new biodegradable plastic film (Gange, 2010). Designed for use in food packaging, the film contains a plasticizer extracted from brine, which improves transparency and makes the plastic easier to form. It was found that when magnesium chloride extracted from brine used in the manufacture of tofu was added to starch used to make biodegradable plastic, it improved the resultant plastic’s sheet forming and hot press molding characteristics. Sheets made with the brine were also found to have improved transparency and flexibility. It also showed heat resistance, hygroscopicity, antibacterial, and water solubility properties. However, as the plastic rapidly

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decomposes when exposed to water, both sides of the film need to be coated in PLA before forming into egg packs, trays, and other food containers. The Fraunhofer UMSICHT Institute reported its development of the Bio-Flex range of biodegradable plastics for use in multilayer films in 2010. Primarily made from renewable raw materials, the product enables processing in conventional extrusion lines without the requirement for further additives. The Bio-Flex range of biocompounds demonstrate a high level of compatibility that provides good bonding between film layers. Bio-flex F 1130 may mainly be used for the production of mulch film, T-shirt bags, and waste bags. It is elastic and ductile and is comparable to LDPE. Bio-Flex F 2110 is more rigid and translucent, but offers impact resistance at low temperatures and its mechanical characteristics are similar to those of HDPE. Bio-Flex A 4100 CL is a transparent PLA blend that converts into blown film and has a high renewable content. The mechanical characteristics of rigid films are comparable to those of PP. According to Smither PIRA, the flexible packaging market is rapidly gaining market share from other sectors, for example, traditional rigid packaging, and was worth 351 billion US dollars by 2018 (www.smitherspira.com/resources/%85/the-shiftfrom-rigid-to-flexible-packaging). The manner in which consumers view and interact with packaged products is changing. There is a focus on sustainability and convenience. Traditional pack types are being replaced by innovative and flexible options designed to meet consumer requirements. Several new product developments have taken place in the area of flexible packaging. One example is the Savvy Green Laundry Detergent Pouch. This shows high-end graphics and offers easy dispensing; another example is the Halls “twist-off” Stickpack converted by Sonoco & Co, a flexible package that allows one sweet to be dispensed without losing others. The benefits of flexible packaging over traditional rigid packaging are presented next. The bottled water sector is a main example of a market in which materials have become lighter and lighter with time and produce less waste. Now PET bottles cannot be made much lighter. The next step is to replace plastic bottles with lightweight, flexible pouches. This development is gaining traction but extensive use has not occurred yet. The reason has been concerns with high-speed filling. The PET bottles can be filled at speeds of 1500 packages per minute, whereas in contrast, the pouches can be filled at a speed of only 400 packages per minute. A few newer technologies for filling PET bottle are designed for transporting the bottle through the cycle via the neck, a development that will also allow the introduction of pouches using the same technology. Water companies would be able to reduce their packaging weight by 50% by the use of pouches. Part of the total cost of a rigid package is the label, and these are applied as part of the filling process. Labels become a bottleneck in the filling process as these are supplied from a different supplier than the bottles. With flexible packaging such as pouches, the

Packaging types

converting of the pouch usually includes full printing features along with the lamination of films if needed. This increases the cost of the pouch slightly and does not have any effect on the filling process itself. Printing options for flexible packaging are innumerable, and can be immediately changed if needed (www.smitherspira.com). Another important feature is the printing of security or brand identity graphics, which is developed for flexible packaging. The challenge is how can security graphics be included in the packaging design without making it obvious to the potential counterfeiter? Pigments can be used that appear under certain lighting, as well as inks that disappear and reappear depending on the environmental conditions. Such technology is not possible with rigid packaging (www.smitherspira.com). One of the major advantages of flexible packaging over rigid packaging is the ability of the company to include the appropriate barrier for the product and end use (https:// www.smitherspira.com/resources/2013/december/the-shift-from-rigid-to-flexiblepackaging). Several products require a reasonable oxygen barrier. Bottles produced from PET, glass, or multilayer paperboard laminates provide a barrier for all products whether it is needed or not. Barrier properties can be provided in flexible packaging. These properties can be moisture and aroma protection that are essentially the same barriers as glass. Aluminum foil has been used as the flexible barrier material, although its properties are compromised by the recent developments in flexible packaging, for instance, stand-up pouches. When creased in this way, the foil can fracture. This leads to pinholes that allow oxygen, water, and light to enter the package. To counter this, new flexible materials have been developed as foil replacement. These are styrene-acrylonitrile, which are tough. Recent methods of production have improved the flexible properties of this resin. Packages produced from flexible plastic films can be made into any shape, and the incorporation of handles, fitments, and opening features is quite simple. Pouches usually have advanced dispensing functions such as screw-top caps and laser-scored tear features. Flexible packaging can also be used to improve rigid packaging materials. An example is shrink labels used for plastic bottles. These labels provide additional barrier protection against light or oxygen and also attractive decoration features. Other important developments include fitments for use with flexible packaging for liquids, with conventional type of dispensing taps leading to connecting valves, oneway dispensers, and pop-up straws. Connecting valves enable consumers to connect a pouch with dishwashing soap directly to the appliance, so the proper amount of detergent is dosed every cycle and cleaning is not needed. Table 4.7 summarizes the advantages of flexible packaging over rigid containers. The market size of flexible packaging has increased as the technology has improved. Now it is also possible to produce packaging of larger sizes. Larger retail flexible packages are now becoming the standard as consumer packaged goods and retail outlets alike reap the benefits of larger packaging. The paperboard carton and unprinted flexible liner used

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Table 4.7 Advantages of flexible packaging over rigid containers.

Flexible packaging requires less storage space Flexible packaging requires less packaging materials Flexible packaging requires less energy to manufacture and to transport, and generates smaller quantities of greenhouse gases on its way to market Flexible packaging is lightweight Flexible packaging is easy to open, carry, store, and reseal Flexible packaging extends the shelf life of many products, especially food, and has a positive sustainability profile Flexible packaging results in less consumer waste being sent to landfills Widely extendible into diverse product categories Maintains and indicates freshness Offers consumer conveniences Provides reclosure and dispensing options Is easily transported and stored Creates shelf appeal Enables visibility of contents Provides efficient product to package ratios Uses less energy Creates fewer emissions Generates less solid waste Improved worker safety Lower shipping cost Creates less waste in the first place Flexible packaging does all the moisture absorption oxygen scavenging and temperature control to keep the product fresh during transit or its idle life. https://www.flexpack.org/advantages

for dry cereals is being replaced with flexible pouches that include high-end graphics and easy-to-reclose features. These packages are usually bigger. Kraft Food’s YesPack for salad dressings and other condiments received a gold medal at the Global Packaging Association Awards. Including benefits of flexible packaging into a large package for food-service liquids, the pouch makes it easier to dispense product, and makes sure that last drop is used. Several new types of pouches have been introduced for large-format liquid packaging as consumers understand the advantages and converters develop new technologies. The flexible packaging industry is promoting more of the “precycling” benefits of their packages against rigid packaging as environmental pressures and uncertain polymer prices continue. Flexible packaging uses less energy and fewer resources in comparison to rigid polymer formats. This would result in some performance advantages over rigid packaging and substantial reductions in packaging costs, materials use, and transport emissions.

Packaging types

Whereas flexible packaging is not really new, the multiple containers are making their way to more and more retail shelves, providing packaging solutions well suited for living in [the] twenty first century. Retailers finally answer to their customers, so buyers yield mighty influence on the packaging selections of producers and retailers. Convenience as well as portability rank high for most modern buyers so package design has taken a turn toward flexible, easy to handle containers. Snacks which were packaged in tins and jars are now found in gusseted flexible pouches on store shelves. For flexible pouches, liquids and gels are also suitable which serve food producers and also nutraceutical packagers. (www.assemblies.com)

Innovation shapes manufacturing and food production, so technological advances also affect packaging. Protection of the product integrity is a main consideration, particularly, when marketing food. Flexible packaging is replacing rigid packaging. This could be partially because advanced materials can provide a high level of product protection. With barrier technology, packagers include multiple layers of protection into every package. The custom wraps shield contents from water, vapor, light, etc. Outer layers are puncture resistant, which provides the benefits of metal containers, without the weight and high-cost materials. Adhesives that bond flexible containers include effective waterand poly-based versions. The retail climate is now getting more sensitive to packaging waste than ever before. Environmental awareness drives brand preferences among buyers increasingly committed to conservation and responsible production practices. Use of flexible packaging substantially reduces the amount of material needed for constructing a package when compared to rigid packaging. Consequently, producers are changing their packaging strategy for better suiting the values of buyers. Producers spend less on flexible packaging than they would on conventional packaging. So, money is saved. Flexible containers are lighter than rigid plastic containers. So transportation costs are reduced. Flexible packaging increases competitiveness in several ways. Improved designs save money by reducing packaging. Flexible packages create unique brand awareness, bringing goods to market in distinctive containers. Freight-friendly flexible packages are less susceptible to breakage as compared to glass, and the effective soft-sided packages help in expanding distribution networks over larger areas. There is movement away from conventional packaging and a significant migration is under way toward flexible packaging. DuPont has developed a hybrid package that combines the advantages of both rigid and flexible packaging in a single injection-molded tub outfitted with flexible side panels. Consumer pressure is not the only driver contributing to the decrease in the use of rigid containers. Manufacturers save money by shifting to flexible packaging. Advanced technology and intense competition are challenging rigid packaging, probably giving way to forward-thinking solutions such as reliable flexible packaging. According to Transparency Market Research report, the flexible packaging market globally is expected to be 358.7 billion US dollars in 2024 (https://cmfenews.com/ flexible-packaging-market-europe-remain-dominant-flexible-packaging-demand). Europe will remain a highly attractive market for the producers of flexible packaging in

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the coming years. Europe would generate revenues of 117.7 billion US dollars in flexible packaging by the end of 2024. Although this increment in demand is expected to stagnate soon, the overall requirement is already large enough to be a very profitable market for the producers. A similar trend is expected for the United States and Canada. Asia Pacific will provide a major opportunity for flexible packaging producers because of a huge demand for better packaging and a growing consumer goods industry. The increasing income of individuals is expected to solidify the consumer goods industry and thereby provide a solid foundation for growth of newcomers. The consumer goods industry is expected to generate a demand of 278.4 billion US dollars for flexible packaging by 2024. This demand is expected to grow at a sluggish rate, but is expected to remain the dominant one because of the sheer volume of its current demand which is stable. A large part of its modest growth rate is ascribed to the growing rate of urbanization in developing countries, a high demand for ready-to-eat foods and the increasing number of nuclear families. (www.transparencymarketresearch.com)

There is a huge demand for flexible packaging in personal care, pharmaceuticals, and tobacco sectors. The key manufacturers of flexible packaging are listed in Table 4.8. Flexible packaging is highly advanced with modified atmospheric packaging, security-enabled packaging, controlled release of packaged content packaging, and several other smart-packaging concepts. Flexible packaging is growing at a fast rate in comparison to rigid packaging, and offers more applications and market potential. Finding the balance for performance and environmental impact will be crucial in the

Table 4.8 Key manufacturers of flexible packaging.

Amcor Limited Bemis Company Sealed Air Corporation Berry Plastics Group, Inc. Mondi Group Sonoco Products Co. Huhtam€aki oyj Constantia Flexibles GmbH Ampac Holdings LLC bischof þ Klein International Wipak Group AR Packaging Goglio Group Schur Flexibles Clondalkin Group Flair Flexible Packaging Solution Cellpack Packaging S€ udpack Verpackungen https://www.transparencymarketresearch.com%9bPackaging

Packaging types

future regarding the use of different types of packaging in various industries (www. adhesives.org/docs/default-document-library/rigid_vs_flexible_pkg_july2010.pdf). “Flexible packaging has become the fastest growing packaging industries. In India, the packaging market is estimated to reach $73 billion by 2020. Indian packaging industry is expected to show 18 percent annual growth rate, with the flexible packaging and rigid packaging expected to grow annually at 25% and 15%, respectively. The developments in flexible packaging have given us a wider range of packaging materials to select from, depending on our bundling needs” (https://warehousebizongo.wordpress.com/%85/ what-types-of-products-are-there-in-flexi).

References Coles, R.E., 2000. Developments in Retail Packaging e Rigid and Flexible Packaging for Consumer Goods. Surrey: Pira International Ltd, 2000. Gange, A., 2010. Biopolymers in Packaging Applications. IntertechPira, USA. Nnamdi, A., 2003. Introduction to Flexible Packaging. Surrey: Pira International Ltd, 2003.

Relevant websites https://cmfenews.com/flexible-packaging-market-europe-remain-dominant-flexible-packaging-demand/. https://warehousebizongo.wordpress.com/2016/10/14/what-types-of-products-are-there-in-flexiblepackaging/. https://warehousebizongo.wordpress.com/%85/what-types-of-products-are-there-in-flexi. www.transparencymarketresearch.com. https://www.transparencymarketresearch.com/rigid-packaging-market.html. https://www.smitherspira.com/resources/%85/the-shift-from-rigid-to-flexible-packaging. https://www.smitherspira.com/%85/2017/%85/what-is-next-for-the-rigid-plastic-packaging. https://www.flexpack.org/advantages. https://www.transparencymarketresearch.com%9bPackaging. http://www.adhesives.org/docs/default-document-library/rigid_versus_flexible_pkg_july2010.pdf. www.packaging.basf.com/p02/Packaging/en/content/%85/starre_kunststoffverpackunge%85. www.smitherspira.com. https://bizongo.in/category/packaging-bags/plastic-bags/carry-bags. www.assemblies.com.

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CHAPTER 5

Biobased polymers in packaging Contents 5.1 Food packaging 5.2 Beverage packaging 5.3 Nonfood packaging 5.4 Food service packaging References Relevant websites

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5.1 Food packaging The fresh food subsector accounts for the largest share of biopolymer-based packaging in the food end use sector (Gange, 2010). Nowadays the use of polymers from renewable raw materials in food packaging is increasing (Weber, 2000a,b; Marsh and Bugusu, 2007; Mensitieri et al., 2011; Pawar and Purwar, 2013). For increasing the shelf life of foods by increasing the preservation and protection from oxidation and microbial spoilage, the trend is to use more natural feedstocks. The use of synthetic films has led to severe environmental problems as these materials are not able to biodegrade (Sabiha-Hanim and Siti-Norsafurah, 2012). The natural biopolymers used in food packaging are available from renewable raw materials. These are biodegradable, biocompatible. All these characteristics lead to environmental safety (Prashanth and Tharanathan, 2007). The structure of monomer used in the preparation of polymer is directly effective on the properties that are needed in different areas of work, including thermal stability, flexibility, good barrier to gases and water, resistance to chemicals, biocompatibility, and biodegradability (Gabor and Tita, 2012). Polymers extracted from natural resources can be degraded and transformed under different environmental conditions and under the action of different microorganisms (Mensitieri et al., 2011). Several researchers have classified the polymers according to their source or production method (Ruban, 2009; Nampoothiri et al., 2010; Mensitieri et al., 2011). Polysaccharides, such as starch and cellulose, are biopolymers, which are found in nature. Other natural polymers are the proteins that can be used to produce biodegradable materials. These polymers are usually chemically modified for modifying the degradation rate and for improving the mechanical properties (Vroman and Tighzert, 2009). The roles of food packaging are to protect food products from outside impact and damage, to contain the food, and to provide information to consumers about the ingredients and nutrition (Coles et al., 2003). Traceability, convenience, and tamper Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00005-9

© 2019 Elsevier Inc. All rights reserved.

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indication are secondary functions of increasing importance. The objective of food packaging is to contain food in an efficient manner that satisfies industry requirements and consumer wishes, maintains food quality, and reduces environmental impact. Within the fresh food subsector, poly(lactic) acid (PLA) leads by material type followed by thermoplastic starch (TPS), whereas thermoformed containers and trays are the most widely used biopolymer based packaging type. Bags and nets for fresh fruit and vegetables, particularly organic references, are also produced from PLA, starch, and cellulose. Polymers derived from starch are the most widely used biopolymers for other food sectors and are mostly used in the manufacture of confectionery trays and flexible biscuit. Cellulose film has effective moisture protection characteristics. It is extensively used in packaging applications for baked and dried food products, including cakes, pastries, bread, rice, cereals, and pasta. More recent packaging applications for PLA include film for confectionery, baked goods, and soft cheese. A snack food manufacturer based in the United States (Snyder’s of Hanover, PA), launched its 100 Calorie Pretzel Variety multipacks packaged in certified compostable outer bags in 2009 (Gange, 2010). The outer bag’s film is a monolayer structure made from EarthClear brand film manufactured by Clear Lam Packaging. The 90% plantbased renewable flexible film, which is based mainly on Ingeo PLA, is capable of running on existing high-speed packaging lines, and also providing high-quality graphic printing and similar barrier properties to more conventional films used in primary packaging. Following this development, Snyder launched its range of Organic Pretzel Sticks packaged in individual bags manufactured from EarthClear in 2010. A bright yellow graphic on the right side of the package differentiates the bag on the shelf and directs the consumer to the back panel for getting more information on the advantages of the renewable packaging. Frito Lay Canada launched its Sun Chips range of extruded multigrain snacks packaged in biodegradable bags based on Ingeo PLA in 2009 (Gange, 2010). Approved by the Biodegradable Products Institute certification program for compostable products, the bags had an ultra-thin metal foil layer inside to maintain freshness with only a minimal effect on compost quality. The company introduced a 100% compostable bag for this product incorporating all layers made from PLA. However, consumer response to the bag was negative in many cases. It was subsequently found that the bags were noisier to use than typically expected. Frito Lay Canada started to change the packaging of five out of six flavor variations to conventional bags, with only Original flavor using the biodegradable reference (Gange, 2010). The feasibility of using biodegradable films suitable for fresh-cut lettuce with commercial vertical form fill seal (VFFS) packaging machines equipped with heat-sealing bars was examined. The films tested included a two-layer laminate consisting of polyethylene (PE) and oriented polypropylene films (OPP), a 0.051 mm biodegradable highdensity polyethylene (HDPE) and a 0.61 mm biodegradable PP. In order for satisfactory closure of bags formed from the films to be achieved, the biodegradable PP and HDPE

Biobased polymers in packaging

required the use of an impulse sealer. The biodegradable polypropylene had a shelf life comparable to that of commercially packaged, pre-cut lettuce, performing well in maintaining the quality while stored for 14 days at 44 F (6.7 C) and 80% relative humidity (Gange, 2010). Improvements were needed for extending the heat seal temperature range of biodegradable films for easier running on commercial VFFS machinery. In the United Kingdom, Lincoln and York, a leading coffee sourcing, roasting, and packing specialist company launched biodegradable packaging for its beans and blends products in 2010 (Gange, 2010). This packaging was developed in response to the growing need for more environmentally friendly packaging options for the home sector. The packaging range is available in several different sizes and in either a transparent or metallized finish, with both formats being suitable for composting. The company conducted extensive tests on the packaging. It was found that the metallized variant decomposed within 1 year and the transparent variant within six to seven months. In recent years, several fiber-based products have been introduced by different companies to replace traditional plastic packaging (Su et al., 2018). These products have excellent functionality and also maintain the inherent advantages associated with natural fibers, including biodegradability. Trayforma boards from Stora Enso are used for food packaging (Storaenso, 2017). They can be tailored to different designs, suitable for different applications. For example, the Trayforma boards used as bowls and plates are made up of top layer (kraft pulp), middle layer (kraft pulp þ CTMP), bottom layer (kraft pulp); customer-designed coatings may also be applied. The boards can be used as the original packaging materials to be heated in a microwave or conventional oven. “Trayforma boards are pure and safe food packaging materials with exceptional formability and printability. Trayforma offers an excellent combination of design, protection and user convenience, from freezer to oven to table. Trayforma boards are easily convertible and extremely stable, offering many opportunities for shelf differentiation. Specially developed for use as pressed or folded trays, bowls and plates, Trayforma board can also be pressed into multi-compartment trays ideal for a wide selection of convenience food” (renewablepackaging.storaenso.com). S€ odra has launched a biocomposite (Durapulp), a mixture of cellulose pulp and the biopolymer polylactic acid (S€ odra, 2016). The biocomposite is suitable for many industrial applications such as molding, air-laid, sheet or board, for packing food and consumer goods. Durapulp is a biocomposite material that consists of renewable and biodegradable components. Its environmental credentials are undeniable, but Durapulp also boasts several other unique features. The material is strong and remains stable under humid conditions. Durapulp is also water repellent, and its end products can be wiped clean and withstand water splashes. Durapulp has a negative carbon footprint, in other words, it has a positive impact on the global carbon balance. It can be molded into an almost infinite number of shapes, dyed to any color, and is resistant to changes in humidity and temperature.

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VTT is developing fiber foam technology (VTT, 2017). Along with an international industrial consortium, VTT has launched a 3.6 million euros project to promote the commercialization of the technology. The main raw materials are wood fibers (virgin or recycled), while nanofibrillated cellulose can be used to enhance the specific properties. The involved processes include: preparing the feed stock, molding (into specific forms), dewatering, and drying. FiberForm packaging consists of 100% cellulose fibers (Billerudkorsn€as, 2017). Some unique properties, for example, a high stretching ability, could be particularly attractive for food packaging. Carlsberg has developed the Green Fiber Bottle products that can be used for beer (Didone et al., 2017). The paper bottles are made by molding, free of inner liners, and completely biodegradable. VTT has developed 100% biobased stand-up pouches with oxygen, grease, and mineral oil barrier properties by using different biobased coatings on paper substrate, which is based on the enzymatic fibrillation of cellulose (HefCell) technology (Eagle, 2017).

5.2 Beverage packaging In the beverage industry, huge investments are being made for expansion and technological upgradation. The packaging of both carbonated and noncarbonated beverages is a complex branch in the food processing/packaging industry. The conventional returnable glass bottles are being replaced by plastic containers and cartons. The current trend is to improve the conventional containers, increase their share in the large market, increase the shelf life of the products, provide greater consumer convenience, and finally to produce economical packages. Intense and relentless competition in the fast-moving global beverage market is driving innovation in packaging on an unprecedented scale. Consumer demands, cost reduction, logistics efficiency, sustainability, and legislation are all major factors spearheading the ongoing changes and developments essential in attracting consumer attention and increasing sales. Established brands continue to innovate in order to maintain market share, whereas new products have the benefit of being able to start from scratch; however, what remains certain is that brands that are not able to keep up will quickly be overwhelmed by competitors. Technical research and development is at the forefront of delivering the required innovation driven by consumer and commercial demands. Biopolymer-based bottles became an increasingly appealing proposition to beverage brand owners aiming to promote differentiation and eco-friendliness (Gange, 2010). PLA is the most widely used biopolymer in beverages packaging and is used in the manufacture of blow-molded bottles. The presence of biopolymer-based materials in the beverage end use sector may be expected to be fortified substantially by growing supply and adoption of renewable resourceederived HDPE. Relatively complex bottle shapes and sizes may be produced with PLA, and monolayer PLA-based bottles may be

Biobased polymers in packaging

produced on existing stretch blow-molding/injection-molding equipment used for polyethylene terephthalate (PET) with no deleterious effects on production rate. But, the adoption of PLA in such cases may require an additional tooling cost and also redesigned preforms. PLA, in some beverage subsectors, is at a disadvantage to PET in terms of barrier properties. Sorption, migration, and inertness tests have shown PLA to be relatively inappropriate for the packaging of oxygen-sensitive carbonated soft drinks and beer. One solution to this, however, proposed by the Fraunhofer Institute for Process Engineering and Packaging, could be an internal coating of silicon dioxide for significantly reducing the oxygen intake of the PLA bottles. Producers of PLA, such as NatureWorks, focused the majority of their activities in the beverage sector on subsectors where barrier property disadvantage was reduced, such as still mineral water. Penetration of PLA into the beverages sector first occurred in the United States during 2005 when several beverage companies marketed some of their products in NatureWorks PLA bottles. These included BIOTA spring water from BIOTA Brands of America, Jivita brand hydrosol infused mineral water from Jivita Waters, and various organic dairy drinks from Naturally Iowa Inc. With regard to the additional environmental benefit of PLA recyclability, several recyclers have expressed concern about the potential contamination of the PET recycling stream with PLA. Studies conducted on behalf of NatureWorks showed that nearinfrared technology could effectively separate PLA from PET without contamination of recycled resin. Some recyclers were not convinced, claiming that the studies failed to simulate real operating conditions; the results were defended by Plastics Forming Enterprises LLC, which conducted the tests. They claimed that PLA could be effectively sorted and recycled under normal recycling conditions in a commercial facility using their described techniques (Gange, 2010). Belu Natural Mineral Water (UK) supported the marketing of its nonsparkling reference packaged in Ingeo PLA bottles promoted as being recyclable and also renewable and biodegradable by conducting bespoke collections and recycling trials using Loopla. Loopla recycling to lactic acid claims to capture embodied energy and returns the product to nature or convert it to recycled PLA (Gange, 2010). Fonti di Vinadio, one of Italy’s leading marketers of mineral water, launched its Santa Anna brand reference packaged in Ingeo PLA manufactured by NatureWorks in 2009. The bottle, available in 0.5 and 1.5 L sizes, uses a vegetable dye to color the bottle green, in order to distinguish it from the usual PET color of blue. The nonpetroleum origin of the bottle material is marketed as an advantage, as it represents an environmental plus, and though the price per unit is higher than PET, it is lower than glass (Gange, 2010). Use of biopolymers in beverages packaging is expected to advance significantly via Coca-Cola Company’s adoption of its PlantBottle conceptda PET bottle containing up to 30% monoethylene glycol derived from the ethanol produced from sugar cane and molasses. The Plant Bottle was initially introduced to some western US states and

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is then expected to be launched in Brazil, Mexico, Japan, and China (Gange, 2010). Coca-Cola reports one of its eventual aims to be the use of nonfood, plant-based waste such as wood chips or wheat stalks to make recyclable PET plastic bottles. Ready to serve fruit beverages and fruit pulps/concentrates, packed in aseptic packages provide excellent protection for fruit juices/pulps. These aseptic packages are produced by combining thermoplastic with paperboard and aluminium foil. Their multi-layered construction allows the carton to protect the contents from several factors responsible for spoilage. The aluminium foil layer is a strong barrier for oxygen and light. The inner plastic layer made of polyethylene makes it possible to seal through the liquid. The outer paper layer provides stiffness making it possible for the cartons in a brick shape, thus, enabling maximum utilisation of available storage and transportation space. Excellent graphics are possible leading to good display and shelf appeal and also providing information regarding the product. The aseptic process makes the product bacteria-free before being packaged. To provide convenient access to the contents, beverage cartons offer a variety of opening devices. A familiar opening feature of the pack is the drinking straw, which is attached to the package. Some recent trends are pull-tab opening, which can be readily detached from a pre-punched hole without compromising the package integrity (icpe.in/ icpefoodnpackaging/pdfs/14_beverages.pdf)

Custom-designed caps and closures can be also incorporated on beverage cartons for pouring easily and for improving the brand image. The beverage cartons are now available in new prisma shape. The unique shape offers maximum display effectiveness and high space efficiency. These packs are stable at room temperature, and the shelf life and nutrient composition of the fruit juice are affected by the barrier properties of the Tetra Pak.

5.3 Nonfood packaging Water-soluble poly(vinyl alcohol) (PVOH) is the leading biopolymer in consumer nonfood packaging applications, followed by starch and PLA (Gange, 2010). Current packaging applications of most significance for PVOH include unit-dose detergent capsules, laundry bags, feminine hygiene products, and wrappings for paper products. Recent applications for starch-based materials in the nonfood end use sector include films for cement sacks and loose-fill padding material. For example, Ciments Calcia, based in France, launched the compostable BioSac cement sack in 2010. The innovation was developed in collaboration with Mondi, Barbier, and Limagrain with further support was provided by Ademe. Traditional cement sacks comprise a protection layer of PE “free film” and double kraft paper layers for strength (Gange, 2010). The BioSac uses the Biolice brand corn flourebased “free film” placed between the kraft paper layers. It provides compostability and biodegradability while retaining the sack attributes of storage and preservation. The corn flour is processed by Limagrain. Barbier converts this to film, which is used by Mondi. Mondi also markets a parallel product branded TerraBag for waste management.

Biobased polymers in packaging

Studies have shown that the sack body decomposes over 8 weeks, whilst the thicker base decomposes over 12 weeks. In 2010, the BioSac achieved the OK compost label and compliance with the EN 13432 standard on compostable and biodegradable packaging. Ongoing research is planned to focus on biodegradable covers for pallets. Storopack, based in the United States, has introduced ergonomic Whisper Systems for the storage and dispensing of loose-fill packaging materials. Available to suit many packaging and shipping requirements, systems range from simple dispensers with hoppers to fully automatic and pneumatic. Storopack launched its PelaspanBio brand biodegradable loose-fill padding material in 2009. The individual chips are designed to interlock to form an effective padding around the packaged product, wedging and locking it in place. PelaspanBio is dust free and antistatic and is particularly suitable for filling out transport packages prior to closure. The compostability of this product is certified according to European Standard EN 13432 and offers the benefits of the S-shaped chip to packaging, but is made of material derived from vegetable starch. PLA’s nonfood packaging applications include bottles in the cosmetics and fragrances subsector and blister packs in the health care subsector. Leoplast, based in France, has been manufacturing PLA-based bottles for cosmetics packaging solutions since 2004, while luxury packaging producer Toly Products Ltd.. has a PLA reference in its Zeta Biozone cosmetics and fragrances packaging range (Gange, 2010). Bormioli Rocco Plastics (Italy) has to date produced around half a million PLA bottles for the fragrances and cosmetics sector and has further plans to develop references based on renewable resourceederived PE. But, penetration of biopolymer-based bottles in the cosmetics and fragrances subsector remains relatively low. In this subsector marketers are disinclined to exchange visual and tactile properties for eco benefits since visually sophisticated packages are required to indicate added value and the luxurious nature of contents, and the look and feel of the product or packaging can be crucial to success. Health care products include those that fall within the areas of pharmaceuticals and medical devices and also consumer health care products with medicated ingredients used for the treatment of specific ailments. Consumer- and brand-related issues that may lead to the use of eco-friendly biopolymer-based packaging alternatives are of relatively low significance in the health care end use sector where practicality and cost-effectiveness are the prime issues. But, there were instances where marketers of health care products focused on and achieved eco-gains for their products via the adoption of biopolymer packaging. For example, Tesco Pharmacies is currently using biodegradable blister packs manufactured by MTS Medication Technologies. The packs were developed to be more environmentally responsible and meet the growing demands of environmentally conscious consumers. The material used in the blister for the packs is produced from PLA, while the conventional foil has been replaced with coated paper and the card is made from recycled board (Gange, 2010).

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Other advancements in biopolymer-packaging applications in the nonfood sector include the development by Gaia Herbs Inc. and Clemson University of a biopolymer-composite bottle for different uses. Branded as EarthBottles, the products are injection blow molded from PLA, reinforced with natural fibers, and compliant with ASTM D6400 (Gange, 2010). Alpha Packaging Co. produced the initial batch of EarthBottles for Gaia, while Plastics Colour Corporation produced the necessary PLAbased composite. In 2010, Netherlands-based Synbra Group announced that its new Biofoam protective packaging had been awarded cradle-to-cradle certification by the country’s Environmental Protection and Encouragement Agency. Biodegradable and renewable BioFoam, made from PLA, is designed for use as protective packaging for medical transportation and horticulture products. The company reported that it was in the process of constructing a new commercial BioFoam manufacturing plant in the Netherlands with a projected capacity of 5,000 tons per year and scheduled to become fully operational very soon. SABIC holds a leading position in the non-food film market in terms of market developments and by having one of the broadest portfolios of film solutions in the industry. SABIC works continuously with its customers in the flexible packaging industry to help reduce the environmental footprint of plastic packaging (www.sabic.com).

5.4 Food service packaging Within the food service end use sector, biopolymer-based packages include trays, containers, lids, wraps, and bags used in the hotels, restaurants, and catering services channels. PLA is the most commonly used biopolymer in food service packaging applications. Leading manufacturers of PLA resin for this purpose include NatureWorks and Cereplast. Starch-based biopolymers are also used in the manufacture of thermoformed foodservice packaging products, while copolyesters may be used as part of a composite with either starch or PLA for foodservice trays and containers. Recently developed PHA biopolymer composites are forecast to increase their penetration in the food service sector because of the price competitiveness. Within the food service end use sector, a significant share of demand for biopolymer-based packaging was accounted for by limited service restaurants. Such establishments benefited from consumer demand for their value as well as convenience and were also key users of disposable food service packaging for both offsite and onsite sales. Demand through smaller limited service outlets, such as fast casual and snack/bakery/coffee shops, also continued to grow to the benefit of packaging demand. Further trends that stimulated growth in the food service end use sector included rising sales of takeout food from full service restaurants, increased catering activity among limited and full service restaurants, and growing sales of prepared food for on-the-go consumption from convenience stores and supermarkets. Although biopolymer-based packaging remained a relatively niche product in the food service packaging sector,

Biobased polymers in packaging

interest and demand in such products also benefited from a rising number of legislative bans on PS-based disposable packaging for take-away food in the United States (Gange, 2010). Cosmo Films is a leading manufacturer of specialty BOPP films in India. This company has launched a special BOPP film that increases the moisture resistance of cement bags. This film is utilized to laminate cement bags that are made of woven PP material. These bags are in commercial use. Indian cement industry has been struggling with significant spoilage of total cement packed because of moisture and formation of lumps. This film provides protection by adding a moisture barrier, but also improves the print quality of the printed material. It is 100% polyolefin and is environment friendly and the bag can be reused. Laminated bags have been used in Pakistan and Bangladesh. These bags are also being used in India. India is the second-largest cement producer after China in the world with production estimates of approximately 300 million tons per annum with production figures estimated to reach 407 million tons per year by 2017. Besides the cement bags and other building materials, these laminated bags could be used to pack a variety of staples. Crawford Packaging provides disposable packaging for food products. They carry a large variety of plastic and paper tableware for the food industry. They are offering cups, bowls, and plates in foam, plastic, and paper formats: paper cups, paper plates, Styrofoam Cups, Styrofoam Plates, Styrofoam Bowls, plastic cups. They carry a variety of food wraps including plastic, foil, and freezer and coated paper. They are also making cake boxes and cake boards for desserts and bakery products. These are available in different shapes, sizes, and colors. Acme Paper is offering a range of disposable packaging products for restaurants, caterers, and other food service establishments. Products include dinnerware (cups, plates, bowls, cutlery); food containers; catering supplies; disposable serve ware; food trays and platters; napkins; cutlery, straws, and stirrers; table covers, etc. Food service packaging items are also available in recyclable, biodegradable, and compostable materials. The food service packaging market is expected to be worth 84.33 billion US dollars by 2022 (www.marketsandmarkets.com/PressReleases/food-service-packaging.asp).

References Billerudkorsn€as, 2017. Shape the Future With BillerudKorsn€as FibreFormÒ. https://www.billerudkorsnas. com/our-offer/packaging-materials/formable-paper. Coles, R., Mc Dowell, D., Kirwan, M.J., 2003. Food Packaging Technology. Blackwell Publishing, CRC Press, Oxford, p. 346. ISBN 0-8493-97788-X. Didone, M., Saxena, P., Brilhuis-Meijer, E., Tosello, G., Bissacco, G., McAloone, T.C., Pigosso, D.C.A., Howard, T.J., 2017. Moulded pulp manufacturing: overview and prospects for the process technology. Packag. Technol. Sci. 30 (6), 231e249. https://doi.org/10.1002/pts.2289.

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Eagle, J., 2017. VTT Creates 100% Bio-Bases Stand-Up Pouch for Crisps, Potato Chips and Muelsei. Retrieved from. http://www.foodqualitynews.com/R-D/VTT-creates-100-biobased-stand-uppouch?utm_source¼copyright&utm_medium¼OnSite&utm_campaign¼copyright. Gabor, D., Tita, O., 2012. Biopolymers used in food packaging: a review. Acta Univ. Cibiniensis. Ser. E: Food Technol. 16 (2), 3e19. Gange, A., 2010. Biopolymers in Packaging Applications. IntertechPira, USA. Marsh, K., Bugusu, B., 2007. Food packaging: roles, materials, and environmental issues. J. Food Sci. 72 (3), R39eR55. Mensitieri, G., Di Maio, E., Buonocore, G.G., Nedi, I., Oliviero, M., Sansone, L., Iannace, S., 2011. Processing and shelf life issues of selected food packaging materials and structures from renewable resources. Trends Food Sci. Technol. 22 (2e3), 72e80. Nampoothiri, M.K., Nair, N.R., Rojan, P.J., 2010. An overview of the recent developments in polylactide (PLA) research. Bioresour. Technol. 101 (22), 8493e8501. Pawar, P.A., Purwar, A.H., 2013. Biodegradable polymers in food packaging. Am. J. Eng. Res. 2, 151e164. Prashanth, K.V.H., Tharanathan, R.N., 2007. Chitin/chitosan: modifications and their unlimited application potentialdan overview. Trends Food Sci. Technol. 18 (3), 117e131. Ruban, S.W., 2009. Biobased packaging - application in meat industry. Vet. World 2 (2), 79e82. Sabiha-Hanim, S., Siti-Norsafurah, A.M., 2012. Physical properties of hemicellulose films from sugarcane bagasse. Procedia Eng. 42 (August), 1390e1395. S€ odra, 2016. About Durapulp. Retrieved from. https://www.sodra.com/en/about-sodra/innovation/durapulp/about-durapulp/. Su, Y., Yang, B., Liu, J., a Sun, B., Cao, C., Zou, X., Lutes, R., He, Z., 2018. Prospects for replacement of some plastics in packaging with lignocellulose materials: a brief review. Bio 13 (2), 4550e4576. https://www.storaenso.com/en/products/paperboard.../food...and-packaging/trayforma. Vroman, I., Tighzert, L., 2009. Biodegradable polymers. Materials 2 (2), 307e344. VTT Technical Research Centre of Finland, 2017. Fiber Cushion for Packaging. Retrieved from. http:// www.vttresearch.com/services/bioeconomy/sustainable-packaging-materials/bio-packaging-materialsand-applications/fiber-cushion-for-packaging. Weber, C. (Ed.), 2000a. The Food Biopack Conference Proceedings, Copenhagen, Denmark, August 27e29, 2000. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-09-7. Weber, C. (Ed.), 2000b. Biobased Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0.

Relevant websites icpe.in/icpefoodnpackaging/pdfs/14_beverages.pdf. www.marketsandmarkets.com/PressReleases/food-service-packaging.asp. www.sabic.com. renewablepackaging.storaenso.com.

CHAPTER 6

Recent trends in packaging of food products Contents 6.1 Active packaging 6.1.1 Oxygen scavengers 6.1.2 Carbon dioxide absorbers and emitters 6.1.3 Antimicrobial packaging 6.1.4 Moisture absorbers 6.1.5 Ethylene scavengers 6.1.6 Ethanol emitters 6.1.7 Flavor/odor absorbers 6.1.8 Antioxidant release 6.1.9 Temperature-controlled packaging 6.1.10 Other active packaging systems 6.2 Intelligent packaging systems 6.2.1 Indicators

141 142 145 146 147 149 149 150 151 151 152 152 154

6.2.1.1 Temperature indicators 6.2.1.2 Freshness indicators 6.2.1.3 Gas indicators

154 155 156

6.2.2 Data carriers 6.2.2.1 Barcodes 6.2.2.2 Radiofrequency identification

6.2.3 Sensors 6.2.3.1 Biosensor 6.2.3.2 Gas sensors

6.2.4 Other systems References Further reading Relevant websites

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161 163 168 168

“Food packaging is a co-ordinated system of preparing food for transport, distribution, storage, retailing, and end-use for satisfying the ultimate consumer with optimal cost. Food packaging is an important part of modern society. Without packaging, commercially processed food could not be handled and distributed efficiently and safely” (Coles et al., 2003) (Table 6.1). Food packaging protects the food product from outside effects, namely light, oxygen, water, and chemical and microbial contamination (Table 6.2). Packaging is required for communicating information to consumers regarding the food in the package (Huff, 2008). Secondary functions are traceability, convenience, Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00006-0

© 2019 Elsevier Inc. All rights reserved.

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Table 6.1 The importance of packaging.

Minimizes handling losses Enables value addition (along with processing) Makes movement of goods, thus trade possible; informs about the packaged contents Provides convenience

Table 6.2 Role of packaging.

Contain the product Protect the product Inform Facilitate handling and distribution Position the product and promote sales

and tamper indication. Food packaging aims to contain food in an economical manner that maintains food safety, satisfies industry and consumer needs, and reduces the environmental impact. Use of active packaging, addresses and even eliminates many of these variables (Erin, 2009). The World Packaging Organization reports “more than 25% of food is wasted due to poor packaging. Thus, optimal packaging can reduce the large amount of food waste. Furthermore, the current consumer demand for convenient and high-quality food products has increased the impact of food packaging” (WPO, 2009; Shin and Selke, 2014). Food packaging makes our lives easier (www.iopp.org). Containment is the most important function of a package. The fresh product not packaged at the store should be transported out in a container. Packaging protects the food from contamination by the microorganisms, dust, gases and water. A food package provides important information regarding the productdits method of preparation and the nutritional content. The consumers can relish the food the way they like, at their convenience. “Food packages can be geared toward a person’s own lifestyle through designs such as portability and single serving dishes. Although traditional packaging covers the basic requirement of food containment, advances in food packaging are expected. Society is becoming increasingly complex and innovative packaging is the result of consumers’ demand for packaging that is more creative and advanced than what is offered currently” (www.iopp.org; Huff, 2008). Recent developments in the area of food packaging are the result of consumer preferences for food products having a longer shelf life (Majid et al., 2016; Dobrucka and Cierpiszewski, 2014). Furthermore, current trends of retail practices and the changes in ways of living are reasons for the development of novel packaging methods not having any impact on the quality of food (Dainelli et al., 2008). Development of innovative

Recent trends in packaging of food products

packaging in the food sector is due to the substantial utilization of packaged foods, and growing use of food packages of smaller size and microwave meals (Restuccia et al., 2010). One more reason for novel food packaging are the issues of microbes resulting from spoilage of food, which demand that the packaging must have antimicrobial effects and the food quality must be retained (Appendini and Hotchtkiss, 2002). Developments in the area of packaging started in the form of electricity-driven packaging machinery, flexible and aseptic packaging, and flexographic printing. Moreover, the inclusion of materials such as polypropylene, polyester, and ethylene vinyl alcohol polymers led to noticeable withdrawal from using glass and metal packaging and paperboard to using flexible and plastic packaging. In the 20th century, the advances in packaging appeared as active packaging and intelligent or smart packaging (Brody et al., 2008). Innovative packaging is the result of consumers’ demand for packaging. The developments in packaging will improve the quality of food and reduce the product losses. This will result in an improved economy (Majid et al., 2016; Vanderroost et al., 2014). In an endeavor to change market opportunities, the packaging sector has resulted in development of different niche markets (Rooney, 2005; Majid et al., 2016). These new ideas of active, intelligent, and bioactive packaging have had a robust effect on marketing of food, and their use and suitability for food applications are presented in the following sections.

6.1 Active packaging Active packaging was used to satisfy the consumer demand for biodegradable packaging materials. Thus, active packaging material from renewable raw materials was developed (Lopez-Rubio et al., 2004; Jin and Zhang, 2008). These materials can degrade by compositing process with lower environmental impact. Active packaging enhances shelf life and improves food quality (Table 6.3). It is able to control and respond to events that take place in the package and is used as a replacement for conventional food processing methods (De Kruijf et al., 2002; Lopez-de-Dicastillo et al., 2011). Use of active packaging depends on the inclusion of certain constituents in the material and inherent properties of the material used as packaging vehicle. A novel development in the area of active packaging is the inclusion of polymeric substances imparting antimicrobial properties (Gontard, 2000; Suppakul et al., 2003). These substances can release active agents, retaining compounds or unwanted food components (Majid et al., 2016; Flores et al., 2007). Scavengers such as cyclodextrins used in the latter application act in an irreversible manner and are either salts or inorganic metals (Lopez-de-Dicastillo et al., 2011). “Controlled delivery of active agents into the food by using packaging films for long periods of storage and distribution limits the development of unwanted flavors produced as a result of directly adding additives into the food. The use of artificial antioxidative agents such as butylated hydroxytoluene, thioester and organophosphate compounds as active packaging additives is limited because of their

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Table 6.3 Active and intelligent packaging systems.

Active and intelligent packaging extend shelf life, allowing food waste reduction. Natural compounds and biodegradable materials are increasing in active packaging. Oxygen scavengers, microwaveable and antimicrobial packaging are growing. More cost-effective and integrated systems are developing in intelligent packaging. Based on Realini, C.E. Marcos, B., 2014. Active and intelligent packaging systems for a modern society. Meat Sci. 98, 404e419.

toxicity as a result of their migration into the food products. Therefore, the use of synthetic additives is now replaced by the use of essential oils” (Majid et al., 2016; Peltzer et al., 2009; Gomez-Estaca et al., 2014). For understanding what active and intelligent/smart packaging have to offer the world of packaging, each phrase should be properly understood. According to Robertson (2006), active packaging is referred to as “packaging in which subsidiary constituents have been intentionally included in or on the packaging material or the package headspace for improving the performance of the package system.” This phrase highlights the importance of adding a substance intentionally to improve the food. This type of packaging actually protects the package and is generally used for protecting the package against oxygen and moisture. Active packaging increases the shelf life for foods and maintains the food quality (Huff, 2008). Active packaging includes some chemical, physical, or biological action that changes interactions between a package, product, and/or headspace of the package for getting the desired result (Yam et al., 2005). Table 6.4 shows a few active packaging systems. Intelligent packaging is referred to as “packaging that contains an indicator which may be external or internal for providing information about the package history and/or the quality of the food” (Robertson, 2006).

6.1.1 Oxygen scavengers These systems scavenge oxygen from the product and can be activated by ultraviolet light (Gander, 2007). Active packaging is available in sachets and pads (placed inside of packages), and active ingredients (added into the packaging materials directly). The oxidative decay of food is expedited when oxygen is present. Oxygen promotes the following (Hogan and Kerry, 2008): • Development of odor and off-flavor • Growth of aerobic microorganisms • Change in color • Nutritional losses • Shelf life stability of muscle foods

Recent trends in packaging of food products

Table 6.4 A few examples of active packaging systems.

Oxygen scavenger: Bakery goods e bread cakes Prepared foods e sandwiches, pizza, ready meals, cured meats and fish, dried foods, and beverages Carbon dioxide scavenger: Coffee, yeast-based goods Carbon dioxide emitter: Bakery goods, prepared foods Ethylene scavengers: Fruit vegetables Ethanol emitter: Bakery goods e cakes, bread Moisture absorber: Meat, poultry, fish, fresh fruit, and vegetables Flavor and odor absorber: Fruit juices, meat, poultry, fish Based on Day, B.P.F., Potter, L., 2011. Active packaging in food and beverage packaging technology, second ed. Coles, R., Kirwan, M. (Ed.), Blackwell Publishing Ltd.

So, controlling oxygen content in food packages is important for limiting the spoilage of food. Although the foods sensitive to oxygen can be packed in modified atmosphere packaging (MAP) or vacuum packaging, these techniques are not able to completely remove oxygen. By using the oxygen scavengers, the change in quality of foods sensitive to oxygen may be reduced (Vermerien et al., 1999; Kerry et al., 2006; L’opez-Rubio et al., 2004). In the meat industry, oxygen scavengers are being successfully used (Kerry et al., 2006). Table 6.5 presents the attributes of commercial oxygen scavengers (Floros et al., 1997; Vermeiren et al., 1999). The oxygen absorbers reduce oxygen content below 100 ppm in package headspace. “Most of the oxygen scavengers are based on iron powder oxidation in the form of small sachets containing various iron based powders as assortment of catalysts. The chemical substances react with the water which is provided by the food to produce a reactive hydrated metallic reducing agent that scavenges oxygen within the food package” (Day, 2008). The oxygen is used alone or combined with MAP for producing oxygen-free conditions in the headspace of packages (Sivertsvik, 2003, 2007). Relatively inexpensive oxygen scavengers have been tried for removing the oxygen left in the MAP (Day, 2003, 2008; Robertson, 2006). “Package inserts in the form of cards, sheets or layers coated onto the inner walls of the package are also used” (Rooney, 1995). Inclusion of oxygen scavengers in the package reduces the possibility of incidental breakage of the sachets and use of their contents (Suppakul et al., 2003). Oxygen scavengers are mixed with highly permeable films. This allows fast diffusion of oxygen and water from the headspace or from food to the reactive constituents. The capacity of oxygen-

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Table 6.5 Attributes of commercial oxygen scavengers.

Biocompatibility Biodegradability Edibility Aesthetic appearance Barrier properties Based on Floros, J.D., Dock, L.L., Han, J.H., 1997. Active packaging technologies and applications. Food Cosmet. Drug Packag. 20, 10e17.; Vermeiren, L., Devlieghere, F., Van Beest, M., de Kruijf, N. Debevere, J. 1999. Developments in the active packaging of foods. Trends Food Sci Tech. 10, 77e86.

scavenging plastic films and laminates is less in comparison to iron-based oxygen scavengers (Biji et al., 2015). Sachets were developed in Japan in the 1970s. The sachets use the process of rusting, or the iron compounds are oxidized in the presence of oxygen and water. Enzyme technology is also used to produce oxygen scavengers. Powdered iron or ascorbic acid is also used. In most packaging lines, iron-based scavengers generally do not clear the metal detector inspections but ascorbic acid can. Oxygen absorbers in sachets have been used in baked materials, coffee, pizzas, dried foods, and meat and poultry products. Sachets absorbing carbon dioxide along with oxygen have been also developed. These are mostly used in coffee packages. Some sachets can release ethanol for increasing the shelf life of bakery products containing high moisture. Ethanol acts as an antimicrobial agent. Drip absorbent pads are used in meat containing packages that may leak when the temperature varies. These absorb water into superabsorbent polymer granules placed between the layers of microporous nonwoven polymer and stop the growth of microorganisms. Sachets are not suitable for every application. These are not suitable for liquid foods and packages produced from flexible film. The rationale is that the film will hold tight to the sachet and stop it from functioning. Sachets generally have the risk of accidental absorption by consumers. These are not successful in Europe, the United States, and Canada (Yam et al., 2005). More recent efforts at active scavenging have focused on adding the scavenger into the packaging material itself. This method has potential for use in polyethylene terephthalate bottles and can be included in many plastic containers and closures. Adding scavengers to the plastic rather than a sachet can avoid many problems. In a tight fitting packaging film such as a cheese pack, a sachet to absorb oxygen cannot be used because the tight fitting film would stifle its functionality. Use of materials absorbing oxygen into the plastic components of the packaging material could be more effective. One way in which oxygen absorbers are being incorporated into plastic materials is the use of absorber (polymer based) that is coextruded in various packaging structures. With UV light, the oxygen absorber is activated so that the scavenging capacity is not exhausted before the end of the shelf life of the product. Some systems use iron based chemistry in their packaging material. Flavor absorbers are also being used in active packaging. Packaging

Recent trends in packaging of food products

materials can absorb flavors from foods. Scalping is now being used to absorb unwanted flavors and odors Majid et al., 2016; Anonymous, 2007; Robertson, 2006.

6.1.2 Carbon dioxide absorbers and emitters Carbon dioxide is good for food preservation and is used as a flushing gas in MAP. When used at high concentration, it hinders the microbial growth on foods and preserves their freshness and increases their shelf life (Cutter, 2002; Puligundla et al., 2012). Carbon dioxide can be added to the packaging for stopping the microbial growth in several food products (Lopez-Rubio et al., 2004; Labuza and Breene, 1988). So, high carbon dioxide levels (10%e80%) are required for increasing the shelf life (Labusa, 1996). In oxygen scavenger packs, removal of oxygen causes a slight vacuum, which could result in collapse in flexible packages. Also when a package is flushed with a mixture of gases including carbon dioxide and oxygen, the carbon dioxide gets dissolved in the product and a partial vacuum is created (Kerry et al., 2006; Vermeiren et al., 1999) because carbon dioxide is soluble at reduced temperatures (Sivertsvik et al., 2003). The method of dissolving carbon dioxide into the product in 1e2 h in pure carbon dioxide before retail is termed as soluble gas stabilization (Sivertsvik, 2000). “Commercial producers of carbon dioxide releasers include Mitsubishi Gas Chemical Co. Ltd. (Ageless TM type G), and Multisorb Technologies Inc. (FreshPax Type M) USA” (Biji et al., 2015). Standard MAP tray can be used for muscle foods. The exudates from the food act with the sachet to release carbon dioxide to the package and this prevents the package from breaking (Kerry et al., 2006). Carbon dioxide scavengers remove excess carbon dioxide in packages (Day, 2008). Mitsubishi Gas Chemical Company is marketing sachets for carbon dioxide scavenging. These scavengers replace the aging process after roasting of coffee, thus preventing the loss of preferred coffee volatiles (Brody et al., 2001). The antimicrobial effect of carbon dioxide is due to its high solubility in foods. The solubility is higher at a lower temperature. Preservative MAP along with high carbon dioxide concentration is used mainly for chilled nonrespiring foods susceptible to microbial contamination. Carbon dioxide also protects foods from oxidation. Nitrogen is commonly used to inhibit oxidation and is used with carbon dioxide for antioxidative food packaging. Including carbon dioxide in package reduces the pressure as it is highly soluble in food matrices and plays a role in balancing the pressures between the inner headspace and the external environment of the package. The concentration of carbon dioxide must be properly limited. An optimum level of carbon dioxide concentration is advantageous for keeping the product fresh by reducing the physiological activities. Maintaining a proper carbon dioxide and oxygen concentration in the package is important for the efficacy of a fresh-produce MAP system. The carbon dioxide produced via the respiration of the produce must be properly balanced with the carbon dioxide that passes out from the package. The same is true for the oxygen supply, which should be balanced with the oxygen consumption of the packaged fresh produce to maintain an optimal oxygen concentration which is in harmony with the carbon dioxide concentration Lee, 2016; Chaix et al., 2014; Singh et al., 2011; Lopez-Rubio et al., 2004.

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6.1.3 Antimicrobial packaging In the area of active packaging, one important development is the controlled release of antimicrobials from the packaging products. Incorporation of antimicrobials in packaging increases shelf life by stopping microbial growth and decay. In the “BioSwitch” system, an antimicrobial is released on command when bacteria grows (de Jong et al., 2005). Antimicrobials in food packaging improve quality by reducing contamination (Brody et al., 2001; Cooksey, 2005; Quintavalla and Vicini, 2002). These substances are added into packaging materials. They are released slowly on the food surface and can also be used in the vapor form. The antimicrobial properties of the following agents are being researched (Wilson, 2007; Appendini and Hotchkiss, 2002): • Silver ions • Ethyl alcohol • Chlorine dioxide • Allyl isothiocyanate • Nisin • Organic acids • Essential oil • Metal oxides Change in the environmental conditions occurs and the antimicrobial responds accordingly. The antimicrobial component of the package is released by external stimulus. The antimicrobial releases on command, and the system works under certain conditions. This increases the specificity of preservation, stability and reduces the chemicals in foods. An example is the addition of polysaccharides, which encapsulate antimicrobial compounds. Several bacteria are able to consume polysaccharides when they grow, and therefore in case of a bacterial contamination, the antimicrobial compounds will be released and the growth of microorganisms will be inhibited. Antimicrobial substances can be added to food packaging materials for controlling unwanted microorganisms on foods (Labuza and Breene, 1989). Natural antimicrobial agents include extracts from spices and other plant extracts. These are also obtained from substances produced by microbial action (Nicholson, 1998). Antimicrobial package material contain agents that migrate to the surface or are effective against surface microorganisms without migration of the active agent to the foods (Han, 2000, 2003). The use of antibacterial products on the surface of food has limited applications because active substances diffuse very fast from the surface to the food or get neutralized on contact. The antimicrobial agents are added to meat products. This could result in partial inactivation of active compounds by meat constituents and exerts little effect on microbes present on the surface of meat (Quintavalla and Vicini, 2002). This type of packaging extends the lag phase and reduces the exponential phase of microbes for

Recent trends in packaging of food products

extending shelf life (Han, 2000). The main potential applications for antimicrobial agents in food include bakery products, cheese, meat, fruits, and vegetables (Labuza, 1987). Bioactive agents added into polymers are used for several applications. In Japan, silver substituted zeolite is the most commonly used antimicrobial agent. Silver ions show a strong antimicrobial effect. The silver zeolite is laminated on the surface of the laminate. Silver ions are released when the aqueous solution from the food enters the cavities (Ishitani, 1995; Quintavalla and Vicini, 2002). “[A] few examples of silver zeolites include Zeomic, Apacider, AgIon, Bactekiller and Novaron. Phenols, fatty acid esters, antioxidants, antibiotics, antimicrobial enzymes and metals are added into polymers” (Hotchkiss, 1997; Appendini and Hotchkiss, 2002). Volatile antimicrobials are released from the packaging system. The packaging material should possess high barrier properties. Ethanol can be sprayed onto foods or ethanol-producing sachets can be used. Ethanol-releasing sachets absorb the moisture and release the ethanol vapor. Ethanol vapor generators are used for bakery products, cheese, and fish. The products are heated before consumption to remove the ethanol. Chlorine dioxide also shows antimicrobial properties. This is produced by the use of sodium chlorite and acid precursors embedded in a hydrophobic and hydrophilic phase of a copolymer. Moisture in the food when comes in contact with the hydrophobic phase, acid is produced that reacts with the sodium chlorite and produces chlorine dioxide. Some antimicrobial packaging uses immobilized antibiotics or fungicides to impede the microbial growth. Examples of antimicrobials with functional groups are enzymes, polyamines, peptides, and organic acids. Certain polymers such as chitosan are of antimicrobial nature and are used in films and coatings. Chitosan is able to protect fresh products from microbial attack. It acts as a barrier between the nutrients contained in the product and microbes. Antimicrobial edible coatings and films produced from polysaccharides, proteins, and lipids show several benefits, which are presented in Table 6.6 (Biji et al., 2015; Appendini and Hotchkiss, 2002; Smith et al., 1995; Brody et al., 2001; Cuq et al., 1995). Whey protein films and coatings include sufficient quantities of edible antimicrobial agents (Cha and Chinnan, 2004; Gennadios et al., 1997; Lopez-Rubio et al., 2004). Nisin immobilized on cellulose casing for reducing the growth of Listeria monocytogenes on meat products was used (Ming et al., 1997). Nisin and lysozyme in soy protein and corn zein films have been utilized for inhibiting bacterial growth (Dawson et al., 1997; Padgett et al., 1998).

6.1.4 Moisture absorbers These are an interesting group of active packaging systems. A main reason of food decaying is the presence of moisture. Moisture absorbants reduce the water activity of the product for reducing the growth of microorganisms (Vermeiren et al., 1999). Sachets and pads are being manufactured by several companies. For dried food applications, activated clays, calcium oxide, silica gel, and minerals are made into tear-resistant plastic

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Table 6.6 Advantages of antimicrobial edible coatings and films.

Iron powder oxidation Ascorbic acid oxidation Photosensitive dye oxidation Enzyme oxidation Saturated fatty acid oxidation Immobilized yeast on solid material, etc. Based on Biji, K.B., Ravishankar, C.N., Mohan, C.O., Srinivasa Gopal, T.K., 2015. Smart packaging systems for food applications: a review. J. Food Sci. Technol. 52 (10), 6125e6135; Appendini, P., Hotchtkiss, J.H., 2002. Review of antimicrobial food packaging. Innov. Food Sci. Emerg. Technol. 3, 113e126; Smith, J.P., Hoshino, J., Abe, Y., 1995. Interactive packaging involving sachet technology. In: Rooney ML, (Ed.) Active Food Packaging, London, UK. Blackie Academic and Professional, pp. 143e173; Brody, A.L., Strupinsky, E.R., Kline, L.R., 2001. Odor removers. In: Brody, A.L., Strupinsky, E.R., Kline, L.R. (Eds.), Active Packaging for Food Applications. Technomic Publishing Company Inc, Lancaster, PA, pp. 107e117; Cuq, B., Gontard, N., Guilbert, S., 1995. Edible films and coatings as active layers. In: Rooney, M.L., (Ed.) Active Food Packaging. Blackie Academic and Professional, Glasgow, UK, pp. 111e142.

sachets. In dry packaged foods, sachets capable of absorbing moisture for humidity control are used. Moisture drip absorbent pads, sheets, and blankets for liquid control in raw foods are being produced. “They consist of two layers of a microporous non-woven plastic film, between which is placed a superabsorbent polymer which can absorb up to 500 times its own weight with water. Typical superabsorbent polymers include carboxymethyl cellulose, polyacrylate salts, and starch copolymers. These polymers have a very strong affinity for water. Moisture drip absorber pads are usually placed under packaged fresh meats for absorbing tissue drip exudates” (www.hiast.edu.vn). Blankets and larger sheets are used to absorb melted ice from chilled seafood during transportation, or for controlling transpiration of horticultural products. These sachets may also contain activated carbon or iron powder (Rooney, 1995). Double-action oxygen and a carbon dioxide scavenger system are also being used. A mixture containing calcium oxide and activated charcoal has been used in polyethylene coffee pouches for scavenging carbon dioxide, but double-action oxygen and carbon dioxide scavenger sachets and labels are used for canned and foil-pouched coffees in the United States and Japan (Day, 1987; Anonymous, 1995; Rooney, 1995). Respiration and condensation occurs in fresh fruits and vegetables when one part of the package is cooler than the other parts. Soluble nutrients leach into the water and cause microbial spoilage. Moisture in the pack causes caking of hygroscopic food products. Drip absorbent sheets consist of two layers of a micro porous polymer sandwiched with a superabsorbent polymer in the form of free flowing granules. Thermarite Pvt. Ltd. (Australia), ToppanTM (Japan), Peaksorb (Australia), LuquasorbTM (Germany), Fresh-R-PaxTM (Atlanta) are [a] few commercial moisture absorbers. Desiccants are generally used in products like nuts, candies, cheese, spices etc. Desiccants such as silica gel, calcium oxide, molecular sieves, are used for dry foods. Micro porous bags or pads of inorganic salts and protected layer of solid polymeric humectants are used for buffering the humidity inside the cartons. Commercial sachets include Tri-Sorb (USA), Desipak (USA),

Recent trends in packaging of food products

2-in-1TM (USA), MINIPAX (USA), STRIPPAX (USA), and the moisture absorbing labels include DesiMax (USA). Biji et al., 2015; Vermeiren et al., 1999; Day, 1998; Brody et al., 2001; Anonymous, 1995; Rooney, 2005.

6.1.5 Ethylene scavengers Ethylene gas speeds up respiration in fresh vegetables and fruits, leading to maturity and softening of tissues (Abeles et al., 1992). Removal of ethylene increases the shelf life of fresh products. Potassium permanganate is the most commonly used agent for ethylene removal (Lopez-Rubio et al., 2004). Physical adsorption on activated carbon or zeolite is also used for removal of ethylene. Potassium permanganate is generally supplied in sachets, whereas other adsorbents may be added in the packaging materials. Ethylene has deleterious effect on shelf life of several vegetables and fruits (Zagory, 1995). Potassium permanganate immobilized on inert minerals is available in sachets. These are placed in product holding rooms without integrating into the food contact packaging material (Labuza and Breene, 1989; Day, 2003). Activated carbon and activated charcoal are used to scavenge ethylene from fresh products. “SedoMate (Japan), Hatofresh (Japan), NeupalonTM (Japan), are few examples of the commercial sachets based on activated carbon for absorbing ethylene. Use of activated clay embedded in polyethylene bags are sold by several companies in United States and Australia. Electron deficient nitrogen containing trienes incorporated ethylene permeable packaging is also used to scavenge ethylene. Films used are silicon polycarbonates, polystyrenes, polyethylenes and polypropylenes” (Biji et al., 2015; Brody et al., 2001; Rooney, 2005; Takashi, 1990). 1-methylcyclopropane is also used for reducing the effect of ethylene (Blankenship and Dole, 2003).

6.1.6 Ethanol emitters Ethanol has been also used as an antimicrobial agent. It is effective on molds, yeasts, and bacteria (Potter et al., 2008). Shelf life of food products can be improved by spraying with 95% ethanol. Ethanol is also produced by the use of sachets releasing ethanol (Rooney, 1995; Labuza and Breene, 1989; Day, 2003). The size of the sachet depends on the weight of food, and the shelf life needed. When food is packed, moisture is absorbed by the food and ethanol vapors are released and diffuse into the package headspace. Ethanol releasers are used to increase the shelf life of bakery products (Rooney, 1995; Day, 2003). Latou et al. (2010) examined extension of shelf life of wheat bread with ethanol releaser alone or combined with an oxygen absorber. Active packaging when combined with a high-barrier packaging material can increase the shelf life of bread significantly. The shelf life based on sensory and microbiological data was: • 4 days for samples without preservatives • 6 days for bread with commercial preservatives • 24 days for samples with ethanol emitter • 30 days for samples with combination of ethanol releaser and an oxygen absorber.

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Ethanol is mainly used in bakeries and is sprayed onto the food products just before packaging. Several uses of ethanol-releasing films and sachets have been patented in Japan. These include “Oitech (Nippon Kayaku Co. Ltd.), ET Pack (Ueno Seiyaku Co. Ltd.), Ageless type SE (Mitsubishi Gas Chemical Co. Ltd.), Ethicap, Antimould 102 and Negamold (Freund Industrial Co.).” These films and sachets contain ethanol in a carrier material that allows the release of ethanol vapor in a controlled manner. Ethanol and water get adsorbed on the silicon powder within a sachet. Moisture from the product activates the releaser and ethanol is released into the headspace or the pack. Ethicap is one of the most popular products. It consists of food grade alcohol and water adsorbed onto silicon dioxide powder and contained in a sachet made of paper and ethyl vinyl acetate copolymer laminate. Traces of flavors are added to mask the smell of alcohol. Double-action ethanol releaser and oxygen scavenger sachets are available. The size of the ethanol releaser depends on the weight and water activity of the food and the shelf life required. When the food is packed in a sachet releasing ethanol, moisture is absorbed by the food and ethanol vapors are released and diffuse into the package headspace. Bakery products packed with ethanol showed reduced staling (Day and Potter, 2011; Lim, 2011).

6.1.7 Flavor/odor absorbers Odor and flavor absorbers are used for removing odors and flavors produced during the reactions occurring during the degradation of the product. These compounds get released when the package is opened and the consumers can detect them. These scavengers are not used in the European Union. Odor is the major method for detection by consumers for determining whether a product is safe for consumption (Vermeiren et al., 2003). There are issues that if the odor were removed, the consumer may consume food not fit for consumption. But, there are opportunities for this type of product with the debittering of pasteurized citrus juices. Some types of oranges are especially susceptible to bitter flavors caused by limonin. Processes are available for debittering of such juices by passing them through columns of nylon beads or cellulose triacetate. The bitterness in grapefruit and lemon juices is caused by the flavanone glycoside naringin. These compounds can be removed by using adsorbers. These materials can be incorporated into the packaging material of the orange juice. The acetate layer contains the enzyme naringinase consisting of L-rhamnosidase and b-glucosidase. Low density polyethylene can also be used in combination with cellulose acetate to reduce limonene. Two types of taints amenable to removal by active packaging are amines. These are produced during the breakdown of fish muscle proteins and aldehydes produced during the autooxidation of fats and oils. Food acids can be used to scavenge amines. Anico bags from Anico Co. consist of a film containing a ferrous salt and an organic acid which oxidise the amines as they are absorbed by the polymer, creating harmless salts. Day and Potter, 2011; Sivertsvik, 2003; Rooney, 1995; Waite, 2003.

Recent trends in packaging of food products

Sodium sulfate and organic sulfates can remove aldehydes. “Tocopherols also absorb aldehydes. Aldehydes can be also produced several weeks after heat processing with products, such as UHT milk. Nylon MXD6, D-sorbitol and cyclodextrin were blended with PET for producing an aldehyde scavenging film (Suloff et al., 2003). The total amount of aldehydes removed from the pack was several times higher with the blended scavenging film in comparison to standard PET films. The aldehyde scavenging film also showed selective scalping, preferring smaller molecular weight aldehydes in comparison to larger molecular weight aldehydes. EKA Nobel and Akzo together developed synthetic aluminosilicate zeolites which adsorb odorous gases within their highly porous state. Their BMHTM powder can be mixed with packaging materials and odorous aldehydes are absorbed in the porous interstices of the powder (Goddard, 1995). Multisorb Technologies offer Minipax and Strippax. These are capable of absorbing mercaptans and hydrogen sulphide. Dupont Polymers have a film, which removes the hydrogen sulphide from packs of cured poultry. New developments include flavour and odor release outside of the pack for attracting the buyers to purchase the product. A controlled release of aroma occurs on the supermarket shelf and when the consumer opens the pack then a further aroma release occurs. By the use of these systems, desired flavour and odors can be developed during storage as the natural properties reduce during shelf life. ScentSational Technologies, LLC, has developed packaging technologies for different industries. This company has developed Encapsulated Aroma ReleaseTM whereby flavours and aromas can be released into the package head space to improve the product. They can also aromatise the packaging material and attract the customers” (Day and Potter, 2011).

6.1.8 Antioxidant release Products containing high oils and fats are susceptible to oxidation, including dry fruits, crisps, and processed meats. Antioxidants can be added in the package for reducing the oxidation. Butylated hydroxytoluene and hydroxyanisole have been added into the package from which they are released during storage. Alpha-tocopherol can also be extruded onto HDPE as an antioxidant. It has a slower release rate in comparison to butylated hydroxytoluene. A large amount of the antioxidant is lost during release but the remaining is absorbed by the food and offers protection. The rate of release is affected by the food inside the package. Acid, alcohol, and fat contents affect the rate of release (Koontz, 2006).

6.1.9 Temperature-controlled packaging This includes the use of innovative insulating materials, self-heating and cooling packs. The self-heating and cooling packs allow the consumer to eat or drink when they work or travel. The principle with self-heating packs is that a button of the can/pouch is pushed, which releases a small amount of water that, when mixed with a salt, causes a reaction and heating the product. Self-heating packs are used for hot drinks. “OnTech

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under the brand name Hillside markets self-heated coffee, cocoa, tea and soups in the United States and Australia. Food Brand Ltd. manufactures self-heating cups called Rocket fuel. This contains a mixture of coffee and guarana. Nuova Bit S.r.l., produces self-heating coffee, tea and chocolate products distributed under the brand name CaldoCaldo. Self-cooling systems are mainly used for soft drinks and beers in cans. Tempra Technologies and Crown Holdings launched a self-cooling can. The refrigeration of the beverage is obtained without using any cooling gas or pressurised system. Different types of beer keg[s] having self-cooling systems are available commercially. Coolkeg_R is a self-cooling beer keg produced by Coolsystem Keg GmbH. This is based on a technology called Zeolite/Water-vacuum developed by Zeo-Tech GmbH. The water absorption properties of zeolites allow the kegs to be returned to the producer in the original state to be refilled and reused. Coca Cola Company has taken a different approach. A self-cooling bottle has been developed that after opening cools the product by producing ice within it” (Day and Potter, 2011; Potter et al., 2008).

6.1.10 Other active packaging systems An important application in the area of active packaging is that the ready meals are packed in self-heating packaging. According to EC/450/2009, self-heating packaging heats food material without using an external heat source or power. Self-venting packaging can control the pressure in the pack, venting the steam when the required pressure and temperature is reached. Microwavable active packaging improves the heating behavior of food by shielding, use of susceptors, and field modification (Regier, 2014). Microwave susceptors consist of stainless steel or aluminum deposited on substrates, which results in uniform heating, surface browning, and crisping (Ahvenainen, 2003; Kerry et al., 2006; Perry and Lentz, 2009). Microwave susceptors are Sira CrispTM (Sirane Ltd.) and SmartPouch (VacPacInc) (Sirane, 2011; VacPac, 2014). “Steam valves are also attached along with the active microwave packs. These allow the easy release of steam during cooking. Flexis Steam Valve from Avery Dennison Corporation is a commercial pressure sensitive steam valve that can be used on most of the flexible food packaging films or moulded containers for cooking convenience food in a microwave. It provides a hermetic seal which can protect the product and becomes self venting during cooking. It regulates a gradual temperature balance during the cooking process for maintaining the quality of food” (Avery Dennison, 2011). Table 6.7 shows commercial active packaging systems.

6.2 Intelligent packaging systems Intelligent packaging systems improve the quality of a product and provide convenience and theft resistance (Robertson, 2006). This monitors food products and provides information to the consumer (Ghaani et al., 2016; Poyatos-Racionero et al., 2018).

Recent trends in packaging of food products

Table 6.7 Commercial active packaging systems.

Oxyguard Toyo Seikan Kaisha Ltd., Japan Iron-based oxygen scavenger Ageless Mitsubishi Gas Chemical Co. Ltd., Japan Iron-based oxygen scavenger Freshilizer Toppan Printing Co. Ltd., Japan Iron-based, oxygen scavenger Bioka Bioka Ltd., Finland Enzyme-based oxygen scavenger Dri-Loc Sealed Air Corporation, USA Absorbent pad Moisture absorber Tenderpac SEALPAC, Germany Dual compartment system Moisture absorber Biomaster Addmaster Limited, USA Silver based Antimicrobial packing Agion Life Materials Technology Ltd., USA Silver-based, antimicrobial packing SANICO Laboratories STANDA, Antifungal coating Interleavers Peakfresh Peakfresh Products Ltd., Australia Activated clay Ethylene scavenger Evert-Fresh Evert-Fresh Corporation, USA Activated zeolites Ethylene scavenger Neupalon Sekisui Jushi Ltd., Japan Activated carbon Ethylene scavenger Based on Biji, K.B., Ravishankar, C.N., Mohan, C.O., Srinivasa Gopal, T.K., 2015. Smart packaging systems for food applications: a review. J. Food Sci. Technol. 52 (10), 6125e6135.

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Intelligent packaging directly measures the food quality inside the package or provides information outside of the package. This method provides information based on its ability to detect external or internal changes in the environment of the product. For measuring the product quality, there should be direct contact between the food product and the quality marker (Huff, 2008). An intelligent system helps the consumer in deciding for increasing the shelf life, improving quality, and warning of possible problems. Intelligent packaging is able to find out possible abuse that takes place during the food supply chain and also informs the consumer when a package has been tampered with. Labels or seals have been developed that are transparent until the package is opened. Once the package is damaged, the label or seal undergoes a color change and may tell “opened” or “stop.” Intelligent packaging can tell the consumer about package tampering that may save their life (www.iopp.org). The intelligent packaging systems involve several technologies shown below: 1. Indicators, inform consumers about the food quality 2. Data carriers (barcodes and radiofrequency identification tags (RFID) are intended for storage, distribution, and traceability purposes 3. Sensors, allow for a rapid and definite quantification of the analytes in foods (Ghaani, et al., 2016; Kerry et al., 2006).

6.2.1 Indicators 6.2.1.1 Temperature indicators There are two types of temperature indicators (Ghaani et al., 2016; Ahvenainen and Hurme, 1997): • Simple temperature indicators • Time temperature integrators (TTIs) Temperature indicators show if products have been heated beyond a critical temperature and warn consumers about the survival of microbes and the protein denaturation during freezing or defrosting (Pault, 1995). TTIs are the first generation of indicators. These are called integrators and monitor temperature changes in the food supply chain. The principle is based on mechanical, chemical, or biological change, which is expressed as a visible response (Taoukis and Labuza, 2003). Because of the important function of time and temperature in affecting the kinetics of deterioration, TTIs obtain information regarding the temperature history of a packaged food over time, thereby avoiding any abuse. TTIs are user friendly (Pereira et al., 2015). They contain labels attached to single packages or larger configurations. When the food is temperature abused, TTI provides information to the consumer. If a food is exposed to a higher temperature, the food quality can get spoiled much faster. A TTI can be placed on shipping containers or packages as a small self adhesive label, and an irreversible change would result when the TTI faces abusive conditions. TTIs are especially useful with chilled foods, where the cold storage during transportation and distribution are important for food

Recent trends in packaging of food products

quality. TTIs are also used as freshness indicators for determining the shelf life of perishable products. A TTI technology known as Timestrip is being used by Nestle in their food service products in the UK. This uses a steady diffusion of liquid through a membrane for measuring the time that has elapsed at a particular temperature (Huff, 2008). This action can provide information about how long a product has been opened or in use. The Timestrip is very useful for products like sauces that are refrigerated and used within a certain time period. (www.iopp.org; Anonymous, 2007)

Table 6.8 shows TTIs’ market applications (Han et al., 2005a; Kuswandi et al., 2011) (Fig. 6.1). Several other examples of TTIs are in the laboratory stage (Ghaani et al., 2016). These are suitable for warning of temperature abuses of frozen food (Yam et al., 2005).

6.2.1.2 Freshness indicators These indicators monitor the food quality throughout storage and transportation (Ghaani et al., 2016). Freshness may be decayed when exposed to harmful conditions. The indicators provide information regarding the product quality (Siro, 2012). The indicators for seafood are based on the total volatile nitrogen content that is produced as the food gets spoiled, and many methods for detection are available (Heising et al., 2015; Kuswandi et al., 2014). Hydrogen sulfide indicators are being used for determining the quality of meat products. It gets released by the meat matrix upon aging. This is often related to the color of myoglobin, which is taken into account as a high-quality attribute for meat products. Based on this principle, Smolander et al. (2002) developed a freshness indicator for modified atmosphere packed poultry meat. Other indicators are based on sensitivity toward other metabolites (Pereira de Abreu et al., 2011). Commercial applications of freshness indicators are shown in Table 6.9 (O’Grady and Kerry, 2008; Ghaani et al., 2016; Pocas et al., 2008).

Table 6.8 TTIs’ market applications.

Monitor mark by fresh-check by Temptime Corporation. (USA) 3M (USA), CoolVu and OnVu by Freshpoint (Switzerland) Checkpoint by Vitsab International AB (Sweden) Tempix by tempix AB (Sweden) Timestrip by Timestrip (UK) Smartpak by Trigon Smartpak Ltd. (UK) Insignia Cold Inspection Intelligent Labels by Insignia Technologies Ltd. (UK) Based on Han, J.H., Ho, C.H.L., Rodrigues, E.T., 2005a. Intelligent packaging. In Han, J.H. (Ed.), Innovations in Food Packaging (p. 139). Elsevier Academic Press, Amsterdam: Ed; Kuswandi, B., Wicaksono, Y., Jayus Abdullah, A., Heng, L., Ahmad, M. 2011.Smart packaging: sensors for monitoring of food quality and safety. Sens. Instrum. Food Qual. Saf., 5, 137e146.

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Figure 6.1 Examples of time-temperature indicators: (A) Fresh-Check by Temptime Corporation (USA) (B) CoolVu by Freshpoint (Switzerland (C) Checkpoint by Vitsab International AB (Sweden) (D) OnVu by Freshpoint (Switzerland) (E) Tempix by Tempix AB (Sweden) and (F) Timestrip by Timestrip (UK). (Reproduced with permission from Temptime Corporation (USA); Freshpoint (Switzerland); Vitsab International AB (Sweden); Freshpoint (Switzerland); Tempix AB (Sweden); Timestrip (UK).)

6.2.1.3 Gas indicators Food is able to change its own atmosphere inside a package as it is capable of respiration. These indicators monitor the gas composition inside a package by producing a change in the color of the indicator through chemical or enzymatic reactions (Ghaani et al., 2016; de Jong et al., 2005). The indicators are kept in contact with the gases surrounding the food in a package. Indicators can tell whether there is a gas leakage in the package, or they

Recent trends in packaging of food products

Table 6.9 Commercial applications of freshness indicators.

Toxinguard by toxin alert inc. to monitor Pseudomonas sp. growth SensorQ by FQSI Inc., which senses spoilage in poultry products and fresh meat RipeSense The ripeness indicator allows consumers to select best quality fruit by detecting aroma components involved in the ripening process Based on O’Grady, M.N., Kerry, J.P., 2008. Smart packaging technology. In F. Toldra (Ed.), Meat Biotechnology. New York: Ed, Springer, pp. 425e451; Ghani et al. (2016); Pocas, M.F.F., Delgado, T.F., Oliveira, F.A.R., 2008. Smart packaging technologies for fruits and vegetables. In Smart Packaging Technologies. John Wiley & Sons Ltd, West Sussex PO19 8SQ, England, pp. 151e166.

can be used to find out the effectiveness of an oxygen scavenger. Gas indicators give signals about the presence or absence of oxygen and or carbon dioxide. Oxygen causes color changes in foods, rancidity, and allows the growth of aerobic microorganisms. Oxygen indicators change the color in the presence of oxygen. The presence of oxygen shows that the package has a leak or has been tampered with. Oxygen indicators give an idea about the sealing of the package. Gas indicators for detecting water vapor, ethanol, and hydrogen sulfide are being developed (Huff, 2008). The most commonly known gas indicators monitor oxygen and carbon dioxide. Research on the development of oxygen and carbon dioxide indicators has been conducted (Jung et al., 2012; Lee and Ko, 2014; Roberts et al., 2011; Vu and Won, 2014). “Most devices are based on redox dyes, a reducing compound and an alkaline compound. These indicators, however, suffer from dye leaching upon contact with the moisture in the package’s headspace. Other developments focus on UV-activated colorimetric oxygen indicators with very limited dye leaching” (Ghaani et al., 2016; Mills et al., 2011; Thai Vu and Won, 2013; Lee et al., 2004, 2005; Roberts et al., 2011; Kuswandi et al., 2011). Trade names for several commercial applications are presented in Table 6.10 (O’Grady and Kerry, 2008; Rodrigues and Han, 2003; Ghaani et al., 2016).

Table 6.10 Gas indicators.

Ageless eye by Mitsubishi Gas Chemical Co. Shelf Life Guard by UPM Vitalon by Toagosei Chemical Inc. Tufflex GS by Sealed Air Ltd. Freshilizer by Toppan Printing Co. Based on O’Grady, M.N., Kerry, J.P., 2008. Smart packaging technology. In F. Toldra (Ed.), Meat Biotechnology. New York: Ed, Springer, pp. 425e451.; Rodrigues, E.T., Han, J.H., 2003. Intelligent packaging. In: Heldman, D.R. (Ed.), Encyclopedia of Agricultural, Food, and Biological Engineering. Marcel Dekker Inc. New York, p. 437; Ghaani, M., Cozzolino, C.A., Castelli, G., Farris, S., 2016. An overview of the intelligent packaging technologies in the food sector. Trends Food Sci. Technol. 51, 1e11.

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6.2.2 Data carriers Data carriers make the information flow within the food supply chain more efficiently. These are also referred to as automatic identification devices (Ghaani et al., 2016). Data carriers actually do not give any information on the food quality but are used for automatization, theft prevention, traceability, or counterfeit protection (McFarlane and Sheffi, 2003). These devices are usually placed onto tertiary packaging. The most important data carrier devices are barcode labels and RFID tags, which belong to the major category of convenience-improving intelligent systems (Robertson, 2012). 6.2.2.1 Barcodes These are used in the retail trade and stores for facilitating inventory control, stock reordering, and checkout because they can be easily used and the cost is low (Ghaani et al., 2016). In the 1970s, the first Universal Product Code barcodes found application (Manthou and Vlachopoulou, 2001). A barcode is a pattern of parallel spaces and bars arranged to represent 12 digits of data. The optical barcode scanner reads the encoded information. This information is sent to a system where it is stored and processed (Han, 2013). Onedimensional barcodes were developed first. “The working is similar to laser beam cutting a horizontal slice from the vertical code bars. As the beam moves over the symbol (Fig. 6.2A), it measures the time it spends scanning dark bars and light spaces. A lookup table is then used to decode individual characters from those times. Because of the line of the laser beam, these kinds of barcodes are referred to as being 1-D. The storage capacity of the first-generation barcode labels was limited, such as to the manufacturer identification’s number and the item number. Reduced Space Symbology barcodes were developed successively to encode more data in a smaller space. The most frequently used RSS symbologies are the RSS-14 stacked omni directional barcode and the RSS expanded barcode, the latter encoding up to 74 alphanumeric characters. Two-dimensional (2-D) barcodes (Fig. 6.2B) allow a larger amount of information to be stored, in comparison to 1-D barcodes, by combining dots and spaces arranged in a matrix, instead of bars and spaces. This allows for an increased density of data within a reduced space. The Portable Data File (PDF) 417 is a 2-D symbol that carries up to 1.1 kB of data in the space of a UPC barcode. The more recent Quick Response 2-D barcode (Fig. 6.2C) allows larger amount of data to be stored using different encoding modes: numeric, alphanumeric, byte/binary, and kanji, the latter referring to logographic Chinese characters. Reading 2-D barcode symbologies requires a scanning device which can simultaneous read in two dimensions” (Ghaani et al., 2016; Kato et al., 2010; Drobnik, 2015; Robertson, 2012; Yam et al., 2009). 6.2.2.2 Radiofrequency identification This technology uses wireless sensors for identifying items and gather data without human involvement (Biji et al., 2015). This technique is based on tags and readers (Tajima, 2007; Hong et al., 2011). RFID tags generally store identification number based

Recent trends in packaging of food products

Figure 6.2 Example of: (A) a 1-D barcode; (B) a PDF 417 2-D barcode; and (C) a QR 2D barcode. (Reproduced with permission from Ghaani, M., Cozzolino, C.A., Castelli, G., Farris, S., 2016. An overview of the intelligent packaging technologies in the food sector. Trends Food Sci. Technol. 51, 1e11.)

on which a reader can recover information about its ID number from the database (Todorovic et al., 2014). There are of two types of RFID tags: passive and active. Passive tags depend on the power provided by the reader. When radio waves are encountered by a passive RFID tag, the coiled antenna within the tag produces a magnetic field. The tag draws energy from it and sends the information encoded in the tag’s memory. Semipassive RFID tags use a battery for maintaining memory in the tag or power the electronics that enable the tag to modulate the electromagnetic waves released by the reader antenna. Active RFID tags have an internal battery that is used to run the microchip’s circuitry and to broadcast a signal to the reader (Vanderroost et al., 2014). RFID has the ability to identify and manage the flow of goods. It is used for traceability control and supply chain management processes ( Jones et al., 2004; Sarac et al., 2010; Ruiz-Garcia and Lunadei, 2011). RFID is more advanced than the zebra blackand-white paper, the barcode system for food traceability ( Jedermann et al., 2009). It provides supply chain visibility, which allows fast and automated processes at supply chain level (Tajima, 2007). Mountable, no flexible sensor-based RFID with tags are available

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for monitoring the temperature, light exposure, relative humidity, pressure, and pH of products. These tags notice the possible intervention of cold chains, which are deleterious to food quality (Vanderroost et al., 2014).

6.2.3 Sensors A sensor detects, locates, or quantifies energy and gives a signal to detect the physical or chemical property to which the device responds (Kress-Rogers1998; Biji et al., 2015; Kress-Rogers1998; Kerry et al., 2006). Sensors provide continuous output of signals. Most of the sensors contain a receptor and a transducer. 6.2.3.1 Biosensor These are used for detecting, recording, and transmitting information about the biological reactions (Biji et al., 2015). These contain bioreceptors and transducers (Yam et al., 2005; Alocilja and Radke, 2003). The bioreceptor recognizes the target analyte and the transducer converts biochemical signals into electronic response that can be quantified. The bioreceptors are either organic or biological materials. The transducers may be optical, acoustic, or electrochemical. The Food Sentinel System (SIRA Technologies Inc.) is a commercial biosensor developed for detecting food pathogens. Specific antibodies are attached to the membrane that forms part of the sensor or the barcode. The pathogens cause the formation of a localized dark bar, which makes the barcode unreadable (Yam et al., 2005). ToxinGuard from Toxin Alert, Canada, is a visual diagnostic system that detects pathogens (Bodenhamer et al., 2004). This is based on antibodies printed on polyethylene-based plastic packaging material. A biosensor for the identification of biogenic amines produced by the decarboxylation of amino acids or by amination and transamination of aldehydes and ketones because of action of microorganisms was developed by Pospiskova et al. (2013). Biosensors for the detection of xanthine were developed by Arvanitoyannis and Stratakos (2012) by immobilization of xanthine oxide on electrodes made up of platinum, silver, and pencil graphite (Devi et al., 2013; Dolmaci et al., 2012; Realini and Marcos, 2014). 6.2.3.2 Gas sensors Gas sensors detect the presence of gases in the package. They include oxygen, carbon dioxide, water vapor, and ethanol sensors; metal oxide semiconductor field effect transistors; organic conducting polymers and piezoelectric crystal sensors; etc. (Biji et al., 2015; Kress-Rogers, 1998; Kerry et al., 2006). Optical oxygen sensors are based on luminescence quenching or change in absorbance caused by direct contact with the analyte (Papkovsky et al., 2002). Optochemical sensors are used for detecting the quality of

Recent trends in packaging of food products

products by sensing gas analyte (Wolfbeis and List, 1995). The optochemical-sensing methods are of the following types (Neurater et al., 1999; Mills et al., 1992): • Fluorescence-based system using a pH-sensitive indicator • Energy transfer strategy using phase fluorimetric detection • Absorption-based colorimetric sensing. Dyes that are pH sensitive are used for developing sensors for the detection of basic volatile amines. Indicators based on methyl red/cellulose membrane, curcumin/bacterial cellulose membrane respond through visible color changes to volatile amines generated during the spoilage of fish (Kuswandi et al., 2012, 2014).

6.2.4 Other systems Other systems are doneness indicators and thermochromic ink convenience-enhancingtype systems (Robertson, 2012). These have not found larger applications in comparison to the above systems. Thermochromic inks are based on thermosensitive inks printed on the package. The color of the ink changes when the temperature is within a specific preset range that is best for food consumption. The color change is accompanied sometimes by a display of a short message, such as ready to serve. Several companies in the world are producing thermochromic inks (Table 6.11). Doneness indicators are also based on the same principle. These indicators provide information to the consumer when the heated food is ready (Robertson, 2012). Another type of intelligent device system deals with theft, counterfeiting, and tampering (Ghaani et al., 2016; Han et al., 2005b). Table 6.12 shows commercial intelligent packaging systems. Table 6.11 Thermochromic inks are produced by several companies.

LCR Hallcrest (USA) CTI Inks (USA) QCR Solutions Corp. (USA) Siltech Ltd. (UK) B&H Color Change (UK) Table 6.12 Commercial intelligent packaging systems.

Ageless Eye Mitsubishi Gas Chemical Inc. Integrity indicator Freshtag COX Technologies Freshness indicator O2 Sense Freshpoint Lab Integrity indicator Continued

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Table 6.12 Commercial intelligent packaging systems.dcont'd

Novas Insignia Technologies Ltd. Integrity indicator Sensorq DSM NV and Food Quality Sensor International Freshness indicator Timestrip Complete Timestrip UK Ltd. Time temperature TimestripPLUS Duo Timestrip UK Ltd. Temperature indicator Monitormark 3M, Minnesota Time temperature indicator Fresh-Check Temptime Corp Time temperature indicator Onvu Ciba Specialty Chemicals and Freshpoint Time temperature indicator Checkpoint Vitsab Time temperature indicator Cook-Chex Pymah Corp Time temperature indicator Colour-Therm Colour Therm Time temperature indicator Thermax Thermographic Measurements Ltd. Time temperature indicator Timestrip Timestrip Ltd. Integrity indicators Novas Insignia Technologies Ltd. Integrity indicators Easy2log CAEN RFID Srl RFID

Recent trends in packaging of food products

Table 6.12 Commercial intelligent packaging systems.dcont'd

Intelligent Box Mondi Plc RFID CS8304 Convergence Systems Ltd. RFID Temptrip Temptrip LLC RFID Based on Biji, K.B., Ravishankar, C.N., Mohan, C.O., Srinivasa Gopal, T.K., 2015. Smart packaging systems for food applications: a review. J. Food Sci. Technol. 52 (10), 6125e6135.

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Suloff, E.C., Marcy, J.E., Blakistone, B.A., Duncan, S.E., Long, T.E., O’Keefe, S.F., 2003. Sorption behaviour of selected scavenging agents in polyethylene terephthalate blends. J. Food Sci. 68 (6), 2028e2033. Suppakul, P., Miltz, J., Sonneveld, K., Bigger, S.W., 2003. Active packaging technologies with an emphasis on antimicrobial packaging and its applications. J. Food Sci. 68, 408e420. Tajima, M., 2007. Strategic value of RFID in supply chain management. J. Purch. Supply Manag. 13, 261e273. Takashi, H., 1990. Japanese Patent 2113849. Taoukis, P.S., Labuza, T.P., 2003. Time-temperature indicators (TTIs). In: Ahvenainen, R. (Ed.), Novel Food Packaging Techniques. Woodhead Publishing Limited, Cambridge, pp. 103e126. Thai Vu, C.H., Won, K., 2013. Novel water-resistant UV-activated oxygen indicator for intelligent food packaging. Food Chem. 140, 52e56. Todorovic, V., Neag, M., Lazarevic, M., 2014. On the Usage of RFID Tags for tracking and monitoring of shipped perishable goods. Procedia Engineering 69, 1345e1349. VacPac, 2014. SmartPouchÒSusceptor Technology for Superior Cooking. http://www.vacpacinc.com/ smartpouch.html. Vanderroost, M., Ragaert, P., Devlieghere, F., Meulenaer, B.D., 2014. Intelligent food packaging: the next generation. Trends Food Sci. Technol. 39, 47e62. Vermeiren, L., Devlieghere, F., Van Beest, M., de Kruijf, N., Debevere, J., 1999. Developments in the active packaging of foods. Trends Food Sci. Technol. 10, 77e86. Vermeiren, L., Heirlings, L., Devlieghere, F., Debevere, J., 2003. Oxygen, ethylene and other scavengers. In: Ahvenainen, R. (Ed.), Novel Food Packaging Techniques. Woodhead Publishing Limited, Cambridge, UK, pp. 22e49. Vu, C.H.T., Won, K., 2014. Leaching-resistant carrageenan-based colorimetric oxygen indicator films for intelligent food packaging. J. Agric. Food Chem. 62, 7263e7267. Waite, N., 2003. Active Packaging. PIRA International, Leatherhead. Wilson, C., 2007. Frontiers of Intelligent and Active Packaging for Fruits and Vegetabels. CRC Press, Boca Raton, Fla, 360 pp. Wolfbeis, O.S., List, H., 1995. Method for Quality Control of Packaged Organic Substances and Packaging Material for Use with This Method. US Patent 5407829. World Packaging Organization (WPO), 2009. Packaging Is the Answer to World Hunger. www. worldpackaging.org/resources/28/. Yam, K.L., Takhistov, P.T., Miltz, J., 2005. Intelligent packaging: concepts and applications. J. Food Sci. 70, R1eR10. Yam, K.L., Takhistov, P.T.W., Miltz, J.W., 2009. Intelligent packaging. In: Yam, K. (Ed.), The Wiley Encyclopedia of Packaging Technology, third ed. John Wiley and Sons Inc, New York, p. 609. Zagory, D., 1995. Ethylene-removing packaging. In: Rooney, M.L. (Ed.), Active Food Packaging. Blackie Academic and Professional, London, UK, pp. 38e54.

Further reading Appendini, P., Hotchkiss, J., 1997. Immobilization of lysozyme on food contact polymers as potential antimicrobial films. Packag. Technol. Sci. 10, 271e279. Brody, A., 2006. Nano and food packaging technologies converge. Food Technol. 60 (3), 92e94. Yam, K.L., 2000. Intelligent packaging for the future smart kitchen. Packag. Technol. Sci. 13, 83e85.

Relevant websites www.iopp.org www.hiast.edu.vn http://3m.com http://fresh-check.com/

Recent trends in packaging of food products

http://www.freshpoint-tti.com/product/coolvu.aspx http://vitsab.com/index.php/tti-label/ http://www.freshpoint-tti.com/links/default.aspx http://tempix.com/the-indicator/ http://timestrip.com

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Environmental impact of biobased polymers Contents References Further reading Relevant websites

178 181 181

Biobased polymers are becoming possible alternatives to conventional petroleum-based plastics (Hottle et al., 2013). Products produced from renewable raw materials are environmentally beneficial because they are potentially biodegradable, save fossil resources, and can help to neutralize global warming (Weber, 2000). Biobased materials include traditional wood, paper, textile materials, and also novel biobased plastics, lubricants, composites, resins, cosmetics, and pharmaceuticals. These materials are produced from biomassdfrom terrestrial and marine plants, parts thereof, and also biogenic residues and waste. The manufacturing processes of biobased materials range from extraction and mechanical processing of natural fibers to fermentation and advanced conversions using enzyme or chemical catalysts. Biobased materials avoid the extraction and emission of fossil carbon by using feedstocks containing biogenic carbon, i.e., carbon removed from the atmosphere through plant photosynthesis. Biobased materials therefore do not depend on nonrenewable energy as feedstock, and the removal of carbon dioxide from the atmosphere helps in reducing their climate change impact. They are included in concepts of more sustainable economies such as the biobased economy and the circular economy. These concepts have received support from advisors at the national and supranational levels and policy makers (OECD, 2009; EC, 2012, 2015; White House, 2012; I&M/EZ, 2016). Products made solely or partially from biomass present an alternative to products only produced by conventional and nonrenewable resourcesdthat is, petroleum, coal, natural gasdand present the potential for a long-term shift away from fossil-based toward a biobased economy (http://innprobio.innovation-procurement.org/fileadmin/user_upload/Factsheets/Factsheet_n_2.pdf ). But for being sustainable, a nonfossil feedstock base is not sufficient. Other aspects, like agricultural practices for growing the biomass, energy used in the production process, process agents like chemicals, solvents, etc., have to be considered for ensuring that a product is sustainable across its life cycle. Nonetheless, biobased materials/products offer improved functionalities with reduced

Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00007-2

© 2019 Elsevier Inc. All rights reserved.

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greenhouse gas (GHG) emissions, reduced toxicity, reduced generation of waste, and better end-of-life options for final disposal. Biobased products not only offer alternative end-of-life options in comparison to their conventional counterparts but can also enter traditional disposal routes, such as recycling or incineration. Depending on the product’s use, not all end-of-life options make sense from an environmental context. Biobased products can be biodegradable, which can set them apart from many conventional products and can be advantageous in many ways, since new biomass can be won from it and the resource can be used many times. If biobased products after their lifetime are subjected to anaerobic digestion process, biogas can be produced and the spent biomass can be used as nutrients for agricultural purposes. However, recyclability is also a very important matter for sustainability, and processing energy demand as well as transport to composting facilities also needs to be taken into consideration when deciding on the most suitable end-of-life option. Furthermore, not all biodegradable products are able to biodegrade under the same conditions. Often, high temperatures are needed, and in almost all cases biodegradability does not mean that products will degrade in the open environment, such as on the ground or in water, but need controlled environments in order for this to happen (as in case of industrial composting). To give an example, biodegradability makes sense within a closed system, but not necessarily in mixed waste streams. For example, for a hospital that has integrated anaerobic digestion facilities that can provide energy directly to the hospital while keeping potentially contaminated products on site, the use of biodegradable products can provide benefits in functionality and for the environment (http:// innprobio.innovation-procurement.org/fileadmin/user_upload/Factsheets/Factsheet_ n_2.pdf ). The environmental impacts of conventional fossil fuelebased, biobased or mineralbased materials are usually measured by using life cycle (LCA) methodology. This technique is internationally standardized (ISO, 2006a, 2006b). It is also known as LCA analysis and cradle-to-grave analysis. It is used to evaluate a product’s impact on the environment over the entire period of its lifedfrom cradle (from raw material extraction) to grave (disposal or recycling, etc.). GHG emissions are one aspect of an environmental LCA. It show the impacts related to the global warming of the Earth’s atmosphere. Other environmental impact categories that can be considered are nonrenewable energy use, exhaustion of fossil resources, eutrophication, acidification, etc. LCAs are found useful in a public procurement process for evaluating the inputs, outputs, and potential environmental impacts of purchasing a particular product all through its life cycle. Life cycle considerations of materials or products are included as part of some eco-labels, namely type I and type II eco-labels. LCAs are important for establishing the sustainability case for biobased products.

Environmental impact of biobased polymers

Figure 7.1 Prevalence of environmental impact indicators (damage or resource indicators) in 72 published life cycle analysis (LCA) studies on biobased (nonenergy) products. (Reproduced with permission Broeren, M.L.M., Zijp, M.C., Waaijers-van der Loop, S.L., Heugens, E.H.W., Posthuma, L., Worrell, E., Shen, L. 2017. Environmental assessment of bio-based chemicals in early- stage development: a review of methods and indicators. Biofuels, Bioprod. Biorefining 11 (4), 701e718. https://onlinelibrary.wiley.com/doi/10.1002/ bbb.1772.)

Fig. 7.1 presents commonly used environmental indicators and shows their commonness in published LCA literature on biobased products (Broeren, 2018; Broeren et al., 2017). Several studies in this area show that the feedstock production life cycle stage is important for the environmental performance of biobased products (Weiss et al., 2012; Hottle et al., 2013; Yates and Barlow, 2013). For instance, biobased products contain carbon dioxide captured from the atmosphere during the growth of plants, reducing effects of climate change. Climate change mitigation is therefore an important driving force for developing a bio-based economy (BBE). In early stage assessment methods, the use of renewable raw materials (instead of fossil fuels) and potential climate change advantages must be included. Biobased materials account for 14% of global bulk materials production, while in contrast synthetic materials account for a 7% share (Deimling et al., 2007; IAI, 2010; Lasserre, 2008; OGJ, 2007; Saygın and Patel, 2010). “Issues regarding GHG emissions and the security of industrial substrate supplies have activated interest in also substituting biomass for traditional fossil fuel-based feedstock in the production of synthetic materials (Deimling et al., 2007; Patel et al., 2006; Shen et al., 2009a, 2009b). Consequently, the production of bio-based synthetic materials such as polymers, lubricants, and fibers has grown in the last decade. In 2008, biomass already provided 10% of the feedstock of the European chemical industry (Rothermel, 2008). Bio-based polymers, such as

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Table 7.1 Energy and greenhouse gas savings.

Biopolymer

Energy savings (MJ/kg)

GHG savings kgCO2 eq/kg polymer

Polylactic acid (PLA) Thermoplastic starch (TPS) TPS þ 60% polycaprolactone

19 51 24

1.0 3.7 1.2

polylactic acid or alkyd resins accounted for 7% of the total polymer production (Plastics Europe, 2007), whereas bio-based plastics (consisting [of] polymers with a molecular mass greater than 20,000 unified atomic mass units) are still in their infancy: by the end of 2007 they accounted for only 0.3%, or 0.36 megatons (Mt) of the worldwide plastics production” (Weiss et al., 2012; Shen et al., 2009a, 2009b). Murphy and Bartle (2004) conducted a study of more than 100 papers on the LCA of biopolymers. Statistical methods were used for compiling the results from the different studies and to produce a consensus view of the major findings. Cradle-to-gate basis biopolymers revealed significant energy and greenhouse gas savings in comparison to low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) (Table 7.1). The route for end-of-life disposal plays an important role in whether the advantages of the renewable raw material are captured across the lifecycle. Composting with full conversion of the carbon to carbon dioxide provides the best results. Methane is a much stronger greenhouse gas compared to carbon dioxide. Therefore, any conversion of carbon to methane loses some of the cradle- to- gate benefits. Methane can be produced in poorly maintained composting systems or in landfill. Technological innovation will open new possibilities for biobased materials (Hermann et al., 2010; Shen and Patel, 2008, 2009a). “Breakthroughs can be expected in the coming years for integrated biorefineries, which may optimize the use of biomass by providing a wide range of materials and energy products from bio-based substrates. However, the prospects for novel bio-based materials present scientists, policy makers, and industry with an environmental challenge: the benefits of replacing fossil fuelbased feedstock and reducing GHG emissions may come at the cost of additional land use and related environmental effects. For making strategic decision[s], a detailed study of the environmental impacts of bio-based materials in comparison with their conventional fossil fuel-based or mineral-based counterparts is needed. LCA studies have been conducted on a variety of bio-based polymers. These include starch-based polymers (Dinkel et al., 1996; Patel et al., 2006; W€ urdinger et al., 2002), fiber composites (M€ uller-S€amann et al., 2002; W€ otzel et al., 1999; Zah et al., 2007), and hydraulic oils and lubricants (Reinhardt et al., 2001). Detailed reviews of the LCA literature showed an initial focus on nonrenewable energy use and GHG emissions only that grew to

Environmental impact of biobased polymers

include additional environmental impact categories like eutrophication and acidification” (Dornburg et al., 2003; Kaenzig et al., 2004; Deimling et al., 2007; Oertel, 2007; Weiss et al., 2007, 2012). But, substantial assessment of the environmental impacts associated with a large variety of biobased materials is not available. Hottle et al. (2013) examined commonly used LCA databases and published LCA studies that assess the environmental sustainability of biobased materials. LCA results from the available literature allow the comparison of environmental impacts. These researchers compared the results for three biobased polymersdpolylactic acid (PLA), polyhydroxyalkanoate (PHA), and thermoplastic starch (TPS)dwith five types of petroleum-derived polymers. These biopolymers showed impacts similar to petroleum-based plastics. LCA results obtained by Belboom and Leonard (2016) show that reduction of GHG emissions and fuel consumption are obtained when fossil HDPE is replaced by biobased HDPE from sugar beet and wheat. The results of 10 LCAs based on disposal cups produced from bioplastics or petroplastics were assessed by Van der Harst and Potting (2013). Conflicting results in terms of global warming potential (GWP) were obtained. The comparison in terms of energy and GHG was made for the fossil fuel-based PET and the biobased polyethylene furandicarboxylate (PEF). Environmental advantage of the PEF based on corn starch was observed (Eerhart et al., 2012). The sustainability of different biopolymers (PLA, PHA, and TPS) was compared to that of other fossil fuel-based polymers in terms of GWP and energy consumption showing the importance of the end of life in the global assessment (Hottle et al., 2013). Environmental impact of biobased ethylene from sugar cane has already been examined using LCA and showed a reduction of GHG emissions and fossil fuel consumption when replacing fossil fuel with bioderived ethanol (Liptow and Tillman, 2012; Alvarenga et al., 2013a,b; Alvarenga and Dewulf, 2013; Van Uytvanck et al., (2014). These results can be mitigated for climate change, in case of direct and indirect land use change (Liptow and Tillman, 2012). Weiss et al. (2012) have reported that “biobased materials save on average, 55  34 GJ/t and 127  79 GJ/(ha*a) of nonrenewable energy. These savings exceed the worldwide average per capita primary energy consumption in the year 2000 by a factor of 8  5 and 18  11, respectively. Furthermore, biobased materials save, on average, 3  1 t carbon dioxide -eq/t and 8  5 t carbon dioxide -eq/(ha*a) of GHG emissions compared to conventional materials (Fig. 7.2). This is equivalent to, respectively, 37  21% and 111  79% of the worldwide average per capita GHG emissions in the year 2000. The results vary across large ranges. This makes it very difficult to identify individual groups of biobased materials which are environmentally superior with respect to nonrenewable energy use and climate change” (Weiss et al., 2012).

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Figure 7.2 Average product-specific environmental impacts of biobased materials in comparison to conventional materials (Dij). Uncertainty intervals represent the standard deviation of data. Numbers in parentheses indicate the sample size for the functional units of per metric ton and per hectare and ~o, M., Bringezu, S., year, respectively. (Reproduced with permission Weiss, M., Haufe, J., Carus, M., Branda Hermann, B., Patel, M.K. 2012. A review of the environmental impacts of bio-based materials. J. Ind. Ecol. 16 (S1), S169eS181.)

Patel et al. (2006) did cradle-to-factory gate analysis on the nonrenewable primary energy use and the GHG emissions of a wide range of biobased chemicals (Fig. 7.3). Their findings match with the results of Weiss et al. (2012) for several biobased materials, showing that the production of biobased chemicals “saves on average, 43  27 GJ/t and reduces the GHG emissions by 3  2 t carbon dioxide -eq/t in comparison to conventional fossil fuel based chemicals.” The variation could be due

Environmental impact of biobased polymers

Figure 7.3 Average nonrenewable primary energy use and greenhouse gas (GHG) emissions of biobased chemicals in comparison to conventional chemicals (Dij). Uncertainty intervals represent the standard deviation of data. Numbers in parentheses indicate the sample size for the biobased and conventional chemicals, respectively. (Reproduced with permission Weiss, M., Haufe, J., Carus, M., ~o, M., Bringezu, S., Hermann, B., Patel, M.K. 2012. A review of the environmental impacts of bioBranda based materials. J. Ind. Ecol. 16 (S1), S169eS181.)

to different assumptions about the type of biomass substrate and the production technology used. Biobased materials are produced by small-scale pilot plants. Advances in biotechnology, technological learning, upscaling of production facilities, and process integration are expected to reduce the environmental impacts and the costs of biobased materials (Hermann et al., 2010; Vink et al., 2010). For quantifying the existing possibilities, LCA results can be combined with evaluation of the technical and economic potential of biobased materials (Saygın and Patel, 2010). Regardless of the present growth rates, biobased materials will require at least a decade for reaching considerable market shares, even at high fossil fuel prices (Saygın and Patel, 2010; Shen et al., 2009b). In the long term, the economy-wide impact of biobased materials on nonrenewable energy use and GHG emissions will be limited because raw materials for synthetic materials production account for only 6% in the global fossil fuel supply. A majority of fossil fuel use and related GHG emissions can be attributed to energy conversions elsewhere in the economy (IEA, 2009). Biobased materials enable the industry to replace renewable substrate for part of its fossil fuelebased substrate and save nonrenewable energy. They typically exert reduced environmental impacts as compared to the traditional materials in the category of climate change (if GHG emissions from indirect land use change are neglected). Biobased materials may apply higher environmental impacts as compared to their conventional counterparts in the categories of eutrophication and stratospheric exhaustion of ozone; the results are not conclusive with regard to acidification and photochemical ozone formation. The environmental impacts of biobased materials span over a wide range. To some extent, this could be due to the diversity of methodological choices and assumptions

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made in the reviewed LCA studies. Therefore, caution must be used when explaining the end result of this meta-analysis. Growing biomass with standard farming practices is the major contributor to the high eutrophication and stratospheric ozone exhaustion potentials of biobased materials. This can be reduced by improving fertilizer management and using extensive farming practices. But, it should be considered that agricultural extensification by, for instance, reducing the use of agrochemicals, may result in reduced crop yields, thus increasing land requirements for production of biomass. The whole life cycle of biobased materials offers the potential for reducing environmental impacts. However, the reduction of land use and its impacts on GHG emissions, eutrophication, and stratospheric ozone exhaustion might be most crucial. Three approaches could be pursued: 1. Increasing the raw material base by using organic wastes, forest and agricultural wastes 2. Using integrated biorefineries permitting a complete utilization of the biomass for producing biobased materials, energy, fuels, and heat 3. Carbon cascading by first using biomass for material and then for energy In developing countries, increasing yields and optimizing agricultural production are of greatest importance. A comprehensive accounting of worldwide land use for both food and nonfood biomass production would allow evaluating the overall effect on direct and indirect land use change as a basis for policy adjustments. Bringezu et al. 2012

References Alvarenga, R., Dewulf, J., De Meester, S., Wathelet, A., Villers, J., Thommeret, R., 2013a. Life cycle assessment of bioethanol-based PVC: part 2: consequential approach. Biofuels Bioprod. Biorefin. 7 (4), 396e405. Alvarenga, R., Dewulf, J., De Meester, S., Wathelet, A., Villers, J., Thommeret, R., 2013b. Life cycle assessment of bioethanol-based PVC: part 1: attributional approach. Biofuels Bioprod. Bioref 7 (4), 385e396. Alvarenga, R., Dewulf, J., 2013. Plastic vs. fuel: which use of the Brazillian ethanol can bring more environmental gains? Renew. Energy 59, 49e52. Belboom, S., Leonard, A., 2016. Does bio-based polymer achieve better environmental impacts than fossil polymer? Comparison of fossil HDPE and bio-based HDPE produced from sugar beet and wheat. Biomass Bioenerg. 85, 159e167. Bringezu, S., O’Brien, M., Schutz, H., 2012. Beyond biofuels: assessing global land use for domestic consumption of biomass. A conceptual and empirical contribution to sustainable management of global resources. Land Use Pol. 29 (1), 24e232. Broeren, M.L.M., Zijp, M.C., Waaijers-van der Loop, S.L., Heugens, E.H.W., Posthuma, L., Worrell, E., Shen, L., 2017. Environmental assessment of bio-based chemicals in early- stage development: a review of methods and indicators. Biofuels, Bioprod. Biorefining 11 (4), 701e718. https://onlinelibrary.wiley. com/doi/10.1002/bbb.1772. Broeren, M., 2018. Sustainable Bio-Based Materials Application and Evaluation of Environmental Impact Assessment Methods. PhD dissertation. Utrecht University, Faculty of Geosciences, Copernicus Institute of Sustainable Development, Energy and Resources group.

Environmental impact of biobased polymers

Deimling, S., Goymann, M., Baitz, M., Rehl, T., 2007. Auswertung von Studien zur o €kologischen Betrachtung von nachwachsenden Rohstoffen bei einer stofflichen Nutzung [Analyzing studies on the ecological evaluation of biomass use for materials]. FKZ 114- 50.10.0236/06-E. PE International, Leinfelden-Echterdingen, Germany. € Kobilanz St€arkehaltiger Kunststoffe [Life Cycle Dinkel, F., Pohl, C., Ros, M., Waldeck, B., 1996. O Assessment of Starch-Based Polymers]. Schriftenreihe Umwelt Nr. 271/I-II. Bundesamt f€ ur Umwelt, Wald und Landschaft (BUWAL), Bern, Switzerland. Dornburg, V., Lewandowski, I., Patel, M.K., 2003. Comparing the land requirements, energy savings, and greenhouse gas emissions reduction of bio-based polymers and bioenergy. J. Ind. Ecol. 7 (3e4), 93e116. EC, 2012. Innovating for Sustainable Growth e A Bioeconomy for Europe. European Commission. Publications Office of the European Union, Luxembourg. https://doi.org/10.2777/6462. EC, 2015. Closing the Loop e An EU Action Plan for the Circular Economy. COM(2015) 614 final. European Commission, Brussels, Belgium. Eerhart, A., Faaij, A., Patel, M., 2012. Replacing fossil based PET with bio-based PEF; process analysis, energy and GHG balance. Energy Environ. Sci. 5 (4), 6407e6422. Hermann, B.G., Blok, K., Patel, M.K., 2010. Twisting bio-based materials around your little finger: environmental impacts of bio-based wrappings. Int. J. Life Cycle Assess. 15 (4), 346e458. Hottle, T., Bilec, M., Landis, A., 2013. Sustainability assessments of bio-based polymers. Polym. Degrad. Stabil. 98 (9), 1898e1907. I&M/EZ, 2016. Nederland Circulair in 2050 e Rijksbreed Programma Circulaire Economie. Ministerie van Infrastructuur en Milieu; Ministerie van Economische Zaken, The Hague, the Netherlands. IAI (International Aluminium Institute), 2010. Historic IAI Statistics. IAI, London, UK. https://stats. world-aluminium.org/iai/stats_new/index.asp. IEA (International Energy Agency), 2009. Energy Balances of Non-OECD Countries. IEA, Organization for Economic Cooperation and Development, Paris, France. ISO (International Organization for Standardization), 2006a. Environmental Management e Life Cycle Assessment e Principles and Framework. ISO 14040. ISO, Geneva, Switzerland. ISO (International Organization for Standardization), 2006b. Environmental Management e Life Cycle Assessment e Requirements and Guidelines. ISO/FDIS 14044. ISO, Geneva, Switzerland. Kaenzig, J., Houillon, G., Rocher, M., Bewa, H., Bodineau, L., Orphelin, M., Poitrat, E., Jolliet, O., 2004. Comparison of the environmental impacts of bio-based products. In: Proceedings of the 2nd World Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection, 10e14 May, Rome, Italy. Lasserre, P., 2008. Global Strategic Management e The Global Cement Industry. http://philippelasserre. net/contenu/Download/Global_Cement_industry.pdf. Liptow, C., Tillman, A.M., 2012. A comparative life cycle assessment study of polyethylene based on sugarcane and crude oil. J. Ind. Ecol. 16 (3), 420e435. M€ uller-S€amann, K.M., Reinhardt, G.A., Vetter, R., G€artner, S.O., 2002. Nachwachsende Rohstoffe in Baden-W€ urttemberg. Identifizierung vorteilhafter Produktlinien zur stofflichen Nutzung unter Ber€ ucksichtigung umweltgerechter Anbauverfahren [Biomass resources in Baden-W€ urttemberg: Identifying environmentally favorable bio-based products]. Report FZKA-BWPLUS, BWA 20002. Murphy, R., I Bartle, I., 2004. Biodegradable Polymers and Sustainability: Insights from Life Cycle Assessment. NNFCC. OECD, 2009. The Bioeconomy to 2030 e Designing a Policy Agenda. Organisation for Economic Co-operation and Development. Oertel, D., 2007. Industrielle Stoffliche Nutzung Nachwachsender Rohstoffe.Sachstandsbericht Zum Monitoring “Nachwachsende Rohstoffe” [The Industrial Use of Biomass. Report on the Monitoring of Biogenic Resources]. Arbeitsbericht, Berlin, Germany. www.tab.fzk.de/de/projekt/zusammenfassung/ ab114.pdf. OGJ, 2007. Worldwide Refinery Survey. Oil and Gas Journal. PennWell Corporation, Tulsa.

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Patel, M.K., Crank, M., Dornburg, V., Hermann, B.G., Roes, A.L., H€ using, B., Overbeek, L., Terragni, F., Recchia, E., 2006. Medium and Long-Term Opportunities and Risks of the Biotechnological Production of Bulk Chemicals from Renewable Resources e The Potential of White Biotechnology. The BREW Project. Prepared under the European Commission’s GROWTH Programme, Utrecht, Netherlands. Plastics Europe, 2007. Business Data and Charts 2006. PlasticsEurope Market Research Group (PEMRG), Brussels, Belgium. Reinhardt, G.A., Herbener, R., G€artner, S.O., 2001. Life-cycle Analysis of Lubricants from Rape Seed Oil in Comparison to Conventional Lubricants. Institut f€ ur Energie- und Umweltforschung Heidelberg (IFEU), Heidelberg, Germany. www.brdisolutions.com/pdfs/bcota/abstracts/13/z312.pdf. Rothermel, J., 2008. Raw material change in the chemical industry e The general picture. . Presentation given in Brussels, Belgium for the German Chemical Industry Association. Saygın, D., Patel, M.K., 2010. Renewables for Industry: An Overview of the Opportunities for Biomass Use. Prepared for the United Nations Industrial Development Organization (UNIDO), Energy and Climate Change Branch. Utrecht University, Utrecht, the Netherlands. Shen, L., Patel, M.K., 2008. Life cycle assessment of polysaccharide materials: a review. J. Polym. Environ. 16 (2), 154e167. Shen, L., Haufe, J., Patel, M.K., 2009a. Product Overview and Market Projection of Emerging Bio-Based Plastics. PRO-BIP 2009. Utrecht University, Utrecht, the Netherlands. Shen, L., Worrell, E., Patel, M.K., 2009b. Present and future development in plastics from biomass. Biofuels, Bioprod. Biorefining 4 (1), 25e40. van der Harst, E., Potting, J., 2013. A critical comparison of ten disposable cup LCAs. Environ. Impact Assess. Rev. 43, 86e96. Van Uytvanck, P., Hallmark, B., Haire, G., Marshall, P., Dennis, J., 2014. Impact of biomass on industry: using ethylene derived from bioethanol within the polyester value chain. ACS Sustain. Chem. Eng. 2 (5), 1098e1105. Vink, E.T.H., Davies, S., Kolstad, J.J., 2010. The eco-profile for current IngeoÒ polylactide production. Ind. Biotechnol. 6 (4), 212e224. Weber, C. (Ed.), 2000. Bio-based Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0. Weiss, M., Patel, M.K., Heilmeier, H., Bringezu, S., 2007. Applying distance-to-target weighing methodology to evaluate the environmental performance of bio-based energy, fuels, and materials. Resour. Conserv. Recycl. 50 (3), 260e281. Weiss, M., Haufe, J., Carus, M., Brand~ao, M., Bringezu, S., Hermann, B., Patel, M.K., 2012. A review of the environmental impacts of bio-based materials. J. Ind. Ecol. 16 (S1), S169eS181. White House, 2012. National Bioeconomy Blueprint. W€ otzel, K., Wirth, R., Flake, M., 1999. Life cycle studies on hemp fiber reinforced components and ABS for automotive sections. Angew Makromol. Chem. 272 (1), 121e127. W€ urdinger, E., Roth, U., Wegener, A., Peche, R., Rommel, W., Kreibe, S., Nikolakis, A., 2002. Kunst€ kobilanz f€ stoffe aus nachwachsenden Rohstoffen: VergleichendeO ur Loose-fill-Packmittel aus St€arke bzw. Polystyrol [Polymers from starch: A comparative life cycle assessment for loose-fill packaging materials from starch and polystyrene]. Projektgemeinschaft. Yates, M.R., Barlow, C.Y., 2013. Life cycle assessments of biodegradable, commercial biopolymersda critical review. Resour. Conserv. Recycl. 78, 54e66. Zah, R., Hischier, R., Leeao, A.L., Braun, I., 2007. Curau’a fibers in the automobile industry e a sustainability assessment. J. Clean. Prod. 15 (11e12), 1032e1040. In: http://innprobio.innovation-procurement. org/fileadmin/user_upload/Factsheets/Factsheet_n_2.pdf.

Environmental impact of biobased polymers

Further reading BIfA/IFEU/Flo-Pak. DBU-Az. 04763. Institut f€ ur Energie und Umweltforschung Heidelberg GmbH, Heidelberg, Germany: Braskem Ethanol-to-Ethylene Plant [Internet]. chemicals-technology.com; c2011. Available from: http://www chemicals-technology. com/projects/braskem-ethanol/. Broeren, M., 2013. Production of Bio-Ethylene-Technology Brief. IEA-ETSAP, IRENA. Cherubini, F., 2010. GHG balances of bioenergy systems e overview of key steps in the production chain and methodological concerns. Renew. Energy 35 (7), C1565eC1573. Cherubini, F., Strømman, A.H., 2011. Life cycle assessment of bioenergy systems: state of the art and future challenges. Bioresour. Technol. 102 (2), 437e451. M€ uhlheim, Germany: Institut f€ ur umweltgerechte Landbewirtschaftung (IfuL) and Heidelberg: Institut f€ ur Energie- und Umweltforschung Heidelberg GmbH (IFEU). Ojeda, T., 2013. Polymers and the environment. In: Yilmaz, F. (Ed.), Polymer Science. InTech, pp. 1e34. Vink, E.T.H., Glassner, D.A., Kolstad, J.J., Wooley, R.J., O’Connor, R.P., 2007. The eco-profiles for current and near-future NatureWorksÒ polylactide (PLA) production. Ind. Biotechnol. 3 (1), 58e81.

Relevant websites http://innprobio.innovation-procurement.org/fileadmin/user_upload/Factsheets/Factsheet_n_2.pdf. https://onlinelibrary.wiley.com/doi/10.1002/bbb.1772.

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CHAPTER 8

Legislation for food contact materials Contents References Further reading Relevant websites

190 190 190

Food has contact with several materials when it is produced, processed, stored, prepared, and served, before it is finally consumed. These materials are termed food contact materials (FCMs). Packaging materials, kitchenware, tableware, machinery for processing food, and containers for transporting food are a few examples. The term does not include water supply equipment. These materials should be nonreactive so that their constituents do not have any harmful effect on the health of consumer or affect the quality of food. In the European Union (EU), for guaranteeing the safety of FCMs, and to speed up the free movement of goods, legal requirements and controls have been adopted. The EU consists of 28 member states. The estimated population is more than 510 million and has developed a single market through a standardized system of laws that is applicable to all the member states. The EU has common policies on business, agribusiness, and regional development, etc. and allows the free movement of people, goods, services, and capital within the internal market, and enacts legislation in justice and home affairs. FCMs are already in contact with food or brought into contact with food, or transfer their constituents to the food under normal or anticipatable use. This includes direct or indirect contact. (ec.europa.eu)

The EU rules can be applied to all types of FCMs and also to certain materials only (Rijk and Veraart, 2010). If there are no specific EU rules, EU law can be complemented with national legislation of the Member States. The European Food Safety Authority (EFSA) has evaluated the safety of FCMs. The safety is examined by the business operators and by the competent authorities of the Member States during official controls. The European Reference Laboratory for FCM maintains scientific information and technical competence on testing methods. Its website includes information regarding the testing of FCMs. Packaging is a major protection against external hazards and provides protection. But, unwanted interactions between food and packaging materials may cause certain problems that can be adequately handled by proper design of packages.

Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00008-4

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The most unwanted interaction takes place when the packaging components migrate into the food. The legislation on FCMs has been developed to tackle this issue. Other unwanted interactions also occur. These involve contamination of packages with microbes, passing of microbes into the packages, and disruption of packages under moist conditions. Good manufacturing practice (GMP) guidelines are used to examine microbial contamination. The conventional and also biomaterials are treated in the same manner in the European FCM legislation and GMP guidelines. Some unwanted interactions are more relevant for one than for the other because of the dissimilarity in origin and properties between conventional and biomaterials. All the present applications of biomaterials as FCMs comply with European legislation. This shows that biomaterials are safe like the conventional materials. The undesirable interaction between food and packaging is migration that is caused by materials coming into contact with food (Weber, 2000). Contamination of food with chemicals has become the driving force for implementing food legislation in the developed countries. Some biomaterials such as paper and regenerated cellulose are well defined, and there is legislation at the national level. New materials have been developed and the manufacturer is responsible for ensuring the safety and suitability for food contact. The safety of FCMs is determined by taking into consideration the toxicological properties and the substances that migrate from the material into food during use. Biomaterials are treated in a similar manner to the conventional materials. The edible coatings are considered as part of the food product and should fulfill the requirements in the legislation on foods. However, certain types of active packaging introduce substances into the food bringing them into an intermediate area where legislation is not defined well. The first regulations in the field of migration were issued in the 1950s by German and Italian authorities, followed by others. The differences in the regulations soon started to cause problems for packaging companies in the EU countries, which were forced to adjust their production to the country of destination. This adjustment led to the requirement of harmonizing the laws so as to obviate the trade barriers. There are five main instruments in European Union legislation: Regulations, Directives, Decisions, Recommendations, and Opinions. Up until now, all legislation pertaining to migration has been in the form of directives. A directive may be simply enacted by the national parliament, much unchanged, but substantial changes are often needed to fit the national legislation and procedures. The Commission made up a Framework Directive setting out the principles, listing the regulated materials, and defining the procedures for use of new materials. The main principle of the Community legislation target was to stop the migration of 86 harmful substances from reaching impermissible levels and also maintain the integrity of the foodstuffs, thereby

Legislation for food contact materials

Table 8.1 Types of food contact materials. Active and intelligent materials and articles

Adhesives Ceramics Cork Glass Ion-exchange resins Metal and alloys Paper and board Plastics Printing inks and colors Regenerated cellulose Rubbers Silicones Textiles Varnishes and coatings Waxes Wood Based on FSAI (Food Safety Authority of Ireland), 2014. Toxicology Factsheet Series. ISSUE No. 1 j JAN 2014. https://www.fsai.ie/publications_foodcontactmaterial/.

preventing contamination, which can change the composition and sensory properties of the food. A wide range of FCM types are available (FSAI, 2014). The list presented in Table 8.1 shows the most common types of FCMs: The plastic regulations do not include varnishes and surface coatings. There are few important criteria which are expressed either in the Framework Directive or in specific directives. Although these are presently applied to plastics, it is worth to take note of them due to their possibility of being basic principles for all other materials (Rossi, 1994). 1. Good manufacturing practices should be used for producing plastics. 2. The constituents of plastics must not be transferred to foodstuffs as to constitute a health problem. 3. Plastics should not transfer their constituents to food in such quantities which may bring an undesirable change in the foodstuff composition and therefore the sensory properties. 4. Plastics must be produced from starting substances mentioned in the plastic directives. 5. Starting substances not given in the list can be used on condition that they are mixtures of approved substances, oligomers, or natural or synthetic compounds or

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mixtures of the two as long as they have been produced from starting substances given within the list. 6. Authorized substances can be used only if they comply with restrictions applicable to them. 7. The substances should be of good quality. (documents.mx; www.bc.bangor.ac.uk) EU legislation for food and packaging aims to protect the health of consumer and remove the technical obstacles (Tariq, 2013). In the EU, the food packaging sector is highly regulated. “The use of recycled materials and articles should be favored in the Community for environmental reasons, provided that strict requirements are established to ensure food safety and consumer protection. Such requirements should be established taking also into account the technological characteristics of the different groups of materials. Priority should be given to the harmonization of rules on recycled plastic material and articles as their use is increasing and national laws and provisions are lacking or are divergent. Therefore, a draft of a specific measure on recycled plastic materials and articles should be made available to the public as soon as possible in order to clarify the legal situation in the Community (Commission Regulation, 2004)”. Food packaging regulations divides itself into two major classes: safety of packaging material and environmental impacts of packaging. The EFSA is responsible for making sure that packaging material in contact with food is not harmful. If any integral part of the packaging material breaks in food, regulatory approvals ought to be taken. The process to obtain indirect food additive is called food additive petition. The company offering packaging materials is requested to show quantity of packaging material breaking in the food to determine if it is within safe limits. The EU legislation notifies the safety of packaging materials, as FCMs should not transfer their components into the foods in unacceptable quantities (migration). The migration limits set by EU legislation are (Tariq, 2013): Overall Migration Limit e 10 mg of substances/dm2 of the food contact surface for all substances which migrate from food contact materials to foods Specific Migration Limit (SML) for individual authorized substances fixed on the basis of a toxicological evaluation. (www.zopa. org; www.worldpackaging.org/wpo/25/)

Specific migration limit has been set up according to the acceptable daily intake or the tolerable daily intake established by the scientific committee on food. This limit is set on the assumption that every day, a person weighing 60 kg eats 1 kg of food packed in plastics containing the substance in the maximum permissible amount. The substance material to be used in the packaging materials may be released from Food and Drug Administration (FDA) if the supplier has received allowance from the EFSA for its purpose. GRAS (generally recognized as safe) is another measure. This ensures the safety of packaging materials as safe to be used. The quantity of the migrant depends upon if the packaging material is utilized for dry or nonfat foods (Tariq, 2013).

Legislation for food contact materials

FCMs contain several substances, including starting substances, monomers, polymer production aids/additives, each of which may contain impurities in the form of microorganisms and chemicals. When these impurities get transferred to food on contact, they spoil the quality of food and also create conditions that may result in unfavorable health effects on consumers. All FCMs fall within the scope of the following two European legislations: Regulation (EC) 1935/2004 on materials and articles intended to come into contact with food, also known as the Framework or FCM Regulation Regulation (EC) 2023/2006 on good manufacturing practices for materials and articles intended to come into contact with food, also known as the GMP Regulation. Therefore, any material considered to be an FCM will need to comply with this legislation. Regulation (EC) No 1935/2004 The principle underlying this Regulation is that any material or article intended to come into contact with food should be sufficiently inert to preclude substances being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition or a deterioration in the organoleptic properties of the food, i.e., a taint in the food. Regulation 1935/2004 requires that FCMs are manufactured in compliance with good manufacturing practice. It also specifies labelling and traceability (one step forward and one step back) requirements for FCMs. Regulation 2023/2006 lays down the rules on GMP that apply to all groups of materials and articles intended to come in contact with food. The list of FCMs covered by this Regulation includes the FCM listed in Annex I of Regulation (EC) No 1935/2004 and combinations of these FCMs, or recycled materials used in them. This Regulation applies to all sectors and stages of manufacture, processing and distribution of materials and articles, but not the production of starting substances. FSAI, 2014 The Framework Regulation allows for specific measures to be acquired for FCMs described above, and as yet, such specific measures have been acquired for the following material types: active and intelligent FCMs, regenerated cellulose, plastics and recycled plastics, and ceramics. Specific measures have also been applied to FCMs containing certain epoxy substances and for teats and soothers made of rubber or elastomers. These FCMs should go along with the Framework and the GMP Regulations and also with their specific measures, which may include curtailment on the production and use of FCMs (FSAI, 2014). Table 8.2 presents European legislation on FCMs, the aims of and other available resources (FSAI, 2014).

187

Table 8.2 European legislation and other resources. Needs to comply with Type of product/contains Active and intelligent materials and articles Adhesives Ceramics Cork

Rubbers

Glass

Ion-exchange resins

Metals and alloys

Paper and board (including tissue paper and napkins)

General measures

Specific measures and guidances Specific regulations

Regulation (EC) No 1935/2004 The principle underlying this regulation is that any material or article intended to come into contact with food should be sufficiently inert to preclude substances to being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition or deterioration in its organoleptic properties Regulation 1935/2004 is applicable to all FCMs

Regulation (EC) No 2023/ 2006 Regulation 2023/2006 lays down the rules on good manufacturing practice (GMP) that applies to all groups of material and articles intended to come in contact with food. The list of FCM covered by this regulation includes the FCMs listed in annex I of regulation (EC) No 1935/ 2004 and combinations of these FCMs or recycled materials used in them This regulation applies to all sectors and stages of: • manufacture • processing • distribution Of materials and articles, but excludes the production of starting substances

Other documents

Regulation (EC) No 450/2009

Council Directive 84/500/EEC Council of Europe Policy Statement concerning cork stoppers and cork materials Council of Europe Policy Statement concerning rubber products Council of Europe Policy Statement concerning lead leaching from glass tableware into foodstuffs Council of Europe Policy Statement concerning ion exchange and adsorbent resins in the processing of food stuffs Council of Europe Policy Statement concerning metal and alloys

None- but food businesses should ensure that in addition to packaging that is made of paper/cardboard, all other paper products that may come into contact with food during food production (such as paper towels used to dry food or on which food is placed during production) also needs to meet the requirements of food contact materials legislation, including the composition of any dyes etc that may have been used in its manufacture

Council of Europe Policy Statement concerning paper and board materials Council of Europe Policy Statement concerning tissue paper kitchen towels and napkins

Who certifies compliance? Self-certification: A company placing a product on the market is responsible for the placement of that product. Therefore, before placing it, the company needs to gather enough information and documentation to know and support without a trace of doubt that the product: • is safe • complies with all the regulations applicable to it

Needs to comply with Type of product/ contains Printing Inks

Plastics

Recycled plastics Regenerated cellulose Silicones

Textiles Varnishes and coatings

Waxes Wood Products containing epoxy substances Teats and soothers

General measures

Regulation (EC) No 1935/2004 The principle underlying this regulation is that any material or article intended to come into contact with food should be sufficiently inert to preclude substances to being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition or deterioration in its organoleptic properties Regulation 1935/2004 is applicable to all FCMs

Regulation (EC) No 2023/ 2006 Regulation 2023/2006 lays down the rules on GMP that applies to all groups of material and articles intended to come in contact with food. The list of FCMs covered by this regulation includes the FCMs listed in annex 1 of regulation (EC) No 1935/2004 and combinations of these FCMs or recycled materials used in them This regulation applies to all sectors and stages of: • manufacture • processing • distribution Of materials and articles, but excludes the production of starting substances

Specific measures and guidances Specific regulations

Other documents

None - but see annex I of regulation (EC) No 2023/2006 for specific requirements for GMP for inks Regulation (EC) No 10/2011

Council of Europe Policy Statement concerning packaging inks applied in the nonfood contact surface area European Commission’s Guidance on regulation 10/2011 European Commission’s Guidance on information on the supply chain

Regulation (EC) No 10/2011 Regulation (EC) No 282/2008 Commission Directive 2007/42/ EC Council of Europe Policy Statement concerning silicone products Council of Europe Policy Statement concerning coatings

WHO certifies compliance? Self-certification: A company placing a product on the market is responsible for the placement of that product. Therefore, before placing it, he company needs to gather enough information and documentation to know and support without a trace of doubt that the product: • is safe • complies with all the regulations applicable to it

Commission Regulation (EC) No 1895/2005 Commission Directive 93/11/EEC

Reproduced with permission from FSAI (Food Safety Authority of Ireland), 2014. Toxicology Factsheet Series. ISSUE No. 1 j JAN 2014. https://www.fsai.ie/publications_foodcontactmaterial/.

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References Commission Regulation, 2004. Regulation (Ec) No 1935/2004 of The European Parliament And of The Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. FSAI (Food Safety Authority of Ireland), 2014. Toxicology Factsheet Series. ISSUE No. 1 j JAN 2014. https://www.fsai.ie/publications_foodcontactmaterial/. Rijk, R., Veraart, R., 2010. Global Legislation for Food Packaging Materials. Wiley-VCH Verlag GmbH & Co. KGaA. Rossi, L., 1994. Future european community directives and petition procedures. Food Addit. Contam. 11, 123e129. Tariq, S., 2013. Success Factors for the Adoption of Bio- Based Packaging in EU Food Industry. Thesis. Master of Science, Stockholm, Sweden, 2013. Weber, C. (Ed.), 2000. Biobased Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0.

Further reading Commission Regulation (EC) no 282/2008. Recycled plastic materials and articles intended to come into contact with food and amending regulation (EC) No. 2023/2006. Offical Journal of EU http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri¼OJ:L:2008:086:0009:0018:EN:PDF pp 20e26.

Relevant websites

ec.europa.eu. documents.mx. www.bc.bangor.ac.uk. www.zopa.org. www.worldpackaging.org/wpo/25/. https://www.fsai.ie/publications_foodcontactmaterial/.

CHAPTER 9

Market for biobased packaging material Contents Reference Relevant websites

196 196

Food packaging material should meet essential performance and also safety standards. It should also meet normal economic price/value needs. For the use of biobased packaging there should be an economic aspect. Currently, the advantages obtained should be weighed against the unquestionable higher price of material as compared to traditional packaging materials. Added value is given if there is a marketing benefit, the biopolymer offers a functional benefit in the product chain and cost benefit within the waste disposal system, or lower taxes result due to legislation (www.bc.bangor.ac.uk). Biopolymers are obtained from sustainable raw materials. Therefore, they are totally complementary to the idea of sustainability. Biobased packaging used for food applications can represent an overall sustainable product concept. Biopolymers possess specific properties that differentiate them from traditional materials. Barrier properties for gases, water vapor are entirely different from those shown by other traditional packaging materials. For fresh products and ready-to-eat foods, extension of the shelf life of the product by a few days can be crucial. Benefit can be obtained if the waste of food packaging is composted together with the food residues. In the Netherlands, the cost of disposal of waste by composting costs little compared to other methods. It is about DFl 100/tons of waste. This cost arises from the fact that categorizing of material and separation of the waste stream is not required if the whole stream can be composted. Biodegradable biopolymers are interesting in this regard. But in several countries, composting is not used on an industrial scale. Biopolymers can be burnt in industrial burners without releasing the unwanted gases. Not much work has been done associated with recycling of biobased polymer packaging. Within the framework of the Packaging Waste Directive composting is accepted as one of the methods available for recovery and re-use of packaging material. This particular section was extended in 2000 to include the recommendations of the CEN Working Party TC261 clearly defining the requirements for the use of descriptions like biodegradability. The growing use of one-way disposable consumption packaging (drink cups, food trays, etc.) has led some authorities to introduce taxes on these items. Biodegradable packaging results in a lower charged tax. For direct food contact packaging, there has not been any benefit shown from lower waste Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00009-6

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disposal tax charges, because of the fact that sufficiently established in-place infrastructure to provide the collection of a separate material stream for composting is absent. (www.bc. bangor.ac.uk)

Table 9.1 shows global market share for biopolymers used in packaging by value, 2010 (%). Prices of biopolymers overall are expected to reduce as production scale, notably of biopolyethylene (bio-PE) increases, which in combination with a continued increase in conventional polymers prices is expected to make biopolymers for packaging more price competitive. Highest growth by type is projected for the other sectors including bio-PE, polyhydroxyalkanoates (PHAs), and lignocellulose-molded fiber composites. This sector is going to be dominated by developments within the supply of bio-PE. The biopolymer packaging market is projected to grow to 3.161 billion US dollars by 2023 from 2.073 billion US dollars in 2018. The demand for biopolymer packaging is driven by growing environmental sustainability issues and the high cost of fossil fuel products (www.businesswire.com/.../3.16-Billion-Global-Biopolymer-PackagingMarket-). Manufacturers are forced to adopt sustainable packaging solutions due to growing environmental concern among consumers, thereby affecting the growth of the global biopolymer packaging market. Furthermore, supportive government initiatives coupled with stringent environmental regulations is further enhancing the market growth. The increasing demand for reduction in carbon footprint by different industries will expand the market for biopolymer packaging in the future. North America will experience a high growth of packaged food and beverage industry because of high purchasing power and higher living standards, thus affecting positively the global biopolymer packaging market. There is good potential for the market to expand in the European region because of increased political awareness about environmental sustainability issues. However, the Asia Pacific region is anticipated to be a main contributor due to rising disposable income and growing awareness regarding good health and fitness, Table 9.1 Global market share for biopolymers used in packaging by value, 2010 (%).

Polylactic acid Starch Cellulose Water soluble Aliphatic-aromatic copolyesters (AAC) Others

29.3% 17.1% 16.4% 13.5% 12.1% 11.6%

Based on Gange, A., 2010. Biopolymers in Packaging Applications, Intertech Pira, USA.

Market for biobased packaging material

environmental concerns, and adoption of Western lifestyle. All these factors are resulting in increasing demand for biopolymer packaging, mainly for the food and beverage packaging industry. But, factors like high prices, limited production capacity, and lack of infrastructure for effective composting will hamper global biopolymer packaging market growth over the forecast period. Food and beverage packaging is the largest market segment. This accounts for about 60% of the market’s total value. The flexible and film packaging sectors are expected to maintain their positions amongst the fastest growing sectors in packaging. In many markets, particularly those where price competition may be expected to increase in the face of dampened consumer demand because of the economic downturn, flexible and film packaging is expected to gain share at the expense of rigid packaging. This general trend may reasonably be expected to benefit sales of biopolymer-based references. Moreover, the cost disadvantage of biopolymer references compared to conventional plastic alternatives is expected to decline on average as price differentials between raw materials are eroded and more economical processes and composites are developed. Within the rigid packaging sector overall, plastic packaging is expected to continue gaining share at the expense of products based on heavier materials such as metal and glass, while demand for biopolymer-based references will benefit from environmental concern and regulation. Renewable resourceederived high-density polyethylene is expected to show the highest growth rate for rigid biopolymer packaging and is expected to find growing application in rigid packaging for production of bottles, caps, and closures. Biopolymer flexible and film plastic packaging will continue to develop new applications while supplanting conventional rigid containers, supported by a complementary lightweight environmental profile, the expansion of key end markets, such as snack foods, pet food, prepared foods, and pharmaceuticals, and improvements in barrier properties. Overall shifts from rigid to flexible and film packaging will increase as companies try to cut costs, sell more unit packages, and make their packaging more environmentally friendly. Changes in food consumption patterns and increased demand for processed food will fuel the overall market for flexible and film plastic packaging. Flexible and film plastic packaging will benefit from the trend toward individually wrapped products: pouches are forecast to record fastest growth by product type. Demand for flexible and film plastic packaging will continue to grow with innovations in breathable films, barrier properties, and resealable stand-up pouches. Some newer applications for flexible and film plastic packaging are replacement of heavier metal cans with spouted flexible packaging, lidding applications, bag-in-box containers with high barriers, and convenience. New biopolymer film structures and coating technology for high-barrier films may enable them to compete more effectively with foil and conventional barrier materials. Material Type Trends Bio-PE is expected to record the greatest actual growth in sales volume by biopolymer packaging material type in

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recent years. This trend will be driven by factors shaping demand for biopolymers overall as well as the marketing activities of Braskem and Dow Chemicals who are expecting to have a combined supply capacity of bio-PE of over half a million tons per year in 2011. Fastest growth in market penetration by bio-PE, which is nonbiodegradable, may be expected to be achieved in North and Latin America where landfill costs, composting infrastructure, and regulatory environments play a lesser role in trends toward biodegradability in packaging compared to Europe. Applications that are expected to provide bio-PE with greatest demand in the field of packaging include bottles, caps, and closures for both beverage and nonfood products. Sales of the current biopolymer packaging leader by material type, polylactic acid (PLA), are expected to show further significant growth in the next few years. Demand is expected to benefit from the advantages associated with increased supply, such as more competitive pricing, as existing producers increase capacity and new suppliers enter the market. BOPLA is one subsector that is expected to record significant development within the PLA sector, driven by investment and fresh produce, bakery, dairy, and confectionery packaging applications. Demand for starch-based biopolymer packaging is also expected to record growth as prices become more competitive and development increases the number of practical applications. However, the sector is expected to be outgrown by emerging bio-PE and PHA sectors. The PHA sector is one of the recently developed in terms of commercialized production and packaging applications, and several companies are expected to develop significant production capacities. Demand for nonrenewable petrochemical-derived biopolymers is forecast to continue growing driven by use in composites in particular, but, the sector will also face strong competition from increasingly price competitive bio-PE. Production capacity for bio-based polymers will triple from 5.1 million tons in 2013 to 17 million tons in 2020, representing a 2% share of polymer production in 2013 and 4% in 2020. The biobased polymer turnover was about V 10 billion worldwide in 2013. Europe loses substantial shares in total production to Asia. In its recently updated market study, the Nova Institute, research partner of the association European Bioplastics, expects bio-based polymers production capacities to grow by more than 400% by 2018. The production capacity for biopolymers boasts very impressive development and annual growth rates, with a compound annual growth rate (CAGR) of almost 20% in comparison to petrochemical polymers, which have a CAGR between 3% and 4% (www.adsalecprj.com/Publicity/MarketNews/lang-eng/.../Article.aspx?tc¼en) Not all bio-based polymers are biodegradable, but some important ones are, e.g., polyhydroxyalkanoates (PHA), polylactic acid (PLA) and starch blends. Strong political support can only be found in Italy and France for biodegradable solutions in the packaging sector. In this sector, the global demand for biodegradable packaging still shows a double digit growth. The most dynamic development is foreseen for the new bio-based polymers polyhydroxyalkanoates (PHA), which belong to the big family of different polymers. PHA production capacity was still small in 2016 and is projected to almost triple by 2021 (https://www.biofuelsdigest.com/.../biobasedpolymer-capacity-expands-4-in-2016-de.)

Market for biobased packaging material

Another most important development is anticipated for polyamides (PA). Its production capacity is expected to virtually double by 2021. Biobased drop-in polyethylene terephthalate (PET) and new biobased polymer PLA have shown about 10% annual growth rates. The packaging industry is the most extensive user of biobased polymers. Most of these are used in rigid packaging (bottles and others) and the remaining are used in flexible packaging (films and others). This is not surprising as biobased PET is one of the largest biobased polymers in terms of capacity. Biobased PET is generally used for producing bottles. The packaging industry is very much interested in biodegradability since packaging is only required for short-term use but large quantities are required. This results in the building up of waste. The use of biodegradable polymers can offer one possible solution to deal with this issue. Different types of polymers get biodegraded in different environmental conditions; some polymers require industrial composting, others work also in home composting, and a limited number work in soil, fresh water, or even in the ocean. So, biodegradability is also important for agriculture and horticultural applications, for instance, mulch films. Apart from packaging, biopolymers are also used in several other applications, particularly in durable applications, for instance, construction or high-performance automotive applications. Biodegradable biopolymers are PHAs, PLA, and starch blends. Of these, the most important development is predicted for the PHA family. PHA production capacity is projected to almost triple by 2021. Of the biobased plastics that are not biodegradable, the future appears bright for the new drop-in materials, bio-PA and bio-PET. The production capacity of the former would increase by two times in 2021. Biobased drop-in PET is expected to grow at a rate of 10% every year, as is, for that matter, that of the new biobased polymer PLA. Strong political support can only be found in Italy and France for biodegradable solutions in the packaging sector. In this sector, global demand for biodegradable packaging still shows double digit growth. Additional demand could come from the increasing microplastic problem (marine littering), but so far biodegradable plastics have not benefitted from this debate (www. bioplasticsmagazine.com/en/news/meldungen/20170222-Bioplastics-market-expands–but-slowerthan-before.php)

The AsiaePacific region is expected to lead the market accounting for more than half of the global production capacity during 2018e23. Packaging industry, particularly rigid packaging, would lead the biopolymers market. The biopolymers are environmentally friendly and find applications in several industries, like automotive, packaging, textile, transportation, etc., where packaging is the largest application for biobased polymers (https://mordorintelligence.com/industry-reports/biobased-polymers-market). The major region for biopolymers and its precursors is the AsiaePacific. The increasing use of bioethanol for chemical building blocks has resulted in setting up of

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large-scale manufacturing facilities for biobased monoethylene glycol (MEG) in India and Taiwan, and for bioethylene precursor for PE, MEG, in Brazil. The share for the AsiaePacific region, where many converters are small- and medium-scale enterprises and cannot afford important modifications to their existing set up, is expected to increase, contrary to the European region. Arkema has reported a 25% expansion in its global polyamide 12 polymers production capacities for meeting growing demand in Asia. Recently, BASF has started a new biobased copolyamide for vacuum skin packaging (mordorintelligence.com). Key Players are BASF SE, Bio Amber, Evonik Industries, Mitsubishi Chemicals, and Blue Sugars, among others. According to a new report from Hexa Research, the bioplastic packaging market worldwide is expected to reach 34.24 billion US dollars by 2024. Europe accounted for 32.7% of the volume share in 2016 because of the supporting regulations coupled with consumer awareness regarding environment conservation (www.hexaresearch. com/press-release/global-bioplastic-packaging-market). Companies are ramping up their production capacity and also foraying into R&D of application of new biopolymers into mainstream applications. The report points to the BASFeAvantium joint venture entered into in October 2016, forming Synvina JV, which will manufacture and market FDCA and PEF. Synvina JV has a production capacity of 50,000 metric tons per year for FDCA and PEF (news.bio-based.eu/global-bioplastic-packaging-market-is-projected-to-bevalued-at-us)

Reference Gange, A., 2010. Biopolymers in Packaging Applications. Intertech Pira, USA.

Relevant websites https://www.adsalecprj.com/Publicity/MarketNews/lang-eng/.../Article.aspx?tc¼en www.bc.bangor.ac.uk. www.biofuelsdigest.com/.../bio-based-polymer-capacity-expands-4-in-2016-de. www.bioplasticsmagazine.com/en/news/meldungen/20170222-Bioplastics-market-expands–but-slowerthan-before.php. www.mordorintelligence.com/industry-reports/bio-based-polymers-marketmordorintelligence.com. www.hexaresearch.com/press-release/global-bioplastic-packaging-market. news.bio-based.eu/global-bioplastic-packaging-market-is-projected-to-be-valued-at-us. www.businesswire.com/.../3.16-Billion-Global-Biopolymer-Packaging-Market-.

CHAPTER 10

Emerging sources of biopolymers Contents References Relevant websites

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Algae is one of the most promising areas of research right now. It is being explored as a feedstock for the production of biofuels and also plastics (Bajpai, 2018; Azeem et al., 2017; Sassi et al., 2017). Algae-based plastics are emerging rapidly into the market. Although very small, they show great promise because these are renewable. The term algae is derived from the Latin word algere, which means seaweeds (Trivedi and, Pandey, 2009). Algae are eukaryotic and mainly aquatic, photosynthetic organisms. The size of algae range from small flagellate micromonas, which are 1 mm in diameter, to giant kelps, which can reach a size of 60 m in length (Kara, 2011). Algae grow very fast. Most of the algal phototrophs consist of long chains of polysaccharides (cellulose, glucan, and galactan). Algae can be a very good source of several natural products, including biopolymers, because of the rapid growth and the presence of various natural compounds (Azeem et al., 2017; Bajpai, 2018; www.algae4ab.eu/pdf/dissemination/01_algae4ab_ sassi_cea_algal_biopolymers.pdf; Velde et al., 2004). Algae are an excellent feedstock for production of biopolymer because of several advantages, for instance, high yield and ability to grow under different environmental conditions (Wei et al., 2013). The yield of algae is 22 kg m2/year, which is much higher in comparison to the land plants (0.5e4.4 kg m2/year). This is an attractive feature that makes them an excellent candidate for use in production of biopolymers (Masarin et al., 2016; Teixeira, 2012). Algae-based plastics have gained more importance recently in comparison to the traditional methods of using feedstock (Abe et al., 2010). Algae produced from natural fibers are now commercially available (Laycock et al., 2013). Algae are photosynthetic organisms ranging from simple unicellular cyanobacteria to complex multicellular macroalgae, possessing organized cellular structures and structurally distinguishing organs, and can grow to very big size. Algae show good photosynthetic efficiency, metabolic plasticity, diverse nature, and can adapt and grow in different types of environments. These properties have made them universal across the earth, although these are commonly found in aquatic environments. As they are able to adapt fast to potentially challenging environments, algae are superb raw material for production of bioenergy and biopolymer (Bajpai, 2018). Substantial opportunities prevail to take advantage of the high photosynthetic capability of macroalgae as well as microalgae for Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00010-2

© 2019 Elsevier Inc. All rights reserved.

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production of biopolymers. “Diverse algal biology and inherent cellular constraints around strain production capacity coupled with large differences in projections about production scenarios for both micro- and macroalgae production impose significant challenges to extrapolating productivity reported within the literature to outdoor cultivation performance over the long term” (www.ieabioenergy.com/.../Laurens-2017Renewable-energy-from-algae-perspective.p). Algae contain photosynthetic pigments. These pigments absorb light energy from the sun, convert it into chemical energy, and store it in the form of photosynthetic products (Ibrahim et al., 2017). The photosynthetic efficiency of algae is higher compared to other plants. Certain algal species are considered among the fastest growing organisms. The photosynthetic efficiency of algae is in the range of 3%e8%, whereas in terrestrial crops it is 0.5%. As the algae are simple organisms capable of photosynthesis and synthesis of a multitude of other compounds that make up the cell, they are attracting a lot of interest from the research community (Bajpai, 2018; Ibrahim et al., 2017; Pelczar et al., 1986; Sharma, 2007). Algae are an excellent substrate for biopolymer production because of several advantages like high yield and the ability to grow in multiple environments. A number of companies, such as Dow Chemical, Petro Sun, and Cereplast, are conducting research in the field of algae biopolymers. Currently, the renewable biopolymers packaging sector enters into competition with food production for resources such as maize, potatoes, wheat, and tapioca. In contrast, algae are a resource with the potential to form a renewable input in the production of biopolymers without such competition. They also offer potential advantages related to growing speed and cultivation conditions. Unlike maize, which takes approximately 100 days to mature, algae may potentially be grown and harvested in around 1 week. Furthermore, algae may be cultivated in seawater requiring only sunlight, carbon dioxide, and nutrients to grow into potentially useful biomass for biopolymer production (Bajpai, 2018). There are estimated to be over 300 thousand species differing by growing environment, properties, nature, and composition. They are prominent in bodies of salt or freshwater. Seaweeds, the largest and most complex marine forms, grow mostly in shallow marine waters. Algae are presently grown successfully on a small scale for the pharmaceutical and health food sectors, although cost-effective large-scale production for the biopolymers industry has yet to be obtained. There remain barriers to algae being produced in such a fashion as well as establishing the best algal type and determining its most effective method of cultivation. However, several investments by multinational businesses and strategic alliances have been made with an objective to resolve such issues. For instance, Shell and HR Biopetroleum formed a joint venture, Cellana, to build an algae plant in Hawaii. Dow Chemical also formed an alliance with Algenol for the latter to produce low-cost ethanol directly from carbon dioxide and seawater using hybrid algae in plastic photobioreactors. BP invested about $10 million in a joint venture with Martek Biosciences for conducting algae production on a commercial scale. In the biopolymers industry, Cereplast Inc., a manufacturer of proprietary biopolymers from renewable substrates,

Emerging sources of biopolymers

is completing research and development of a family of algae-based resins (www. businesswire.com/news/.../Cereplast-Begins-Bioplastics-Production-Indian). These resins reportedly have the potential of replacing 50% or more of the petroleum used in traditional plastic resins. This company is presently in contact with potential chemical conversion businesses that could convert, on a large scale, algal biomass into viable monomers for further conversion into biopolymers. Cereplast has planned a preliminary production capacity of 30,000 tons per year (Gange, 2010). Soley Biotechnology Institute is producing biodegradable bioplastic from Spirulina dregs. This company has been a research leader in the area of microalgae since 2000. A large volume of dregs are produced as a by-product of extraction of some of the useful materials from Spirulina microalgae. Sapphire Energy Inc., Algenol, and Solazyme Inc. are the three companies that have showcased their prominence in the global algae market. Other players such as Pond Biofuels Incorporated and Algae Tec are looking to make their presence known in the market. According to TMR the global algae market would expand at a 7.39% CAGR during 2016e24 to generate around US$1.1 bn by the end of 2024. Open pond cultivation could continue to generate higher demand in the market. North America is anticipated to take the lead in the market. In 2016, USA accounted for an 87.6% share of the regional market (chemicalenegry.blogspot.com/2019/01/ algae-market-to-surge-at-robust-pace-in.html). There has been a significant rise of the world algae market in the recent years. In the recent years, the need to shift from fossil fuel resources to renewable energy sources has become prominent. This may be due to the increase in carbon emission from different industries. Consequently, demand for algal biomass is expected to increase at a significant rate since it is an important ingredient used to produce biofuel. Vendors operating in the world algae market could expect attractive growth opportunities birthing on the back of high focus on the use of renewable energy sources in both developing and developed countries. Moreover, increasing demand for biofuel owing to the implementation of strict emission standards and policies is forecasted to set the tone for significant growth in the market (http://chemicalenegry.blogspot.com/2019/01/algaemarket-to-surge-at-robust-pace-in.html).

The international algae market in the future would slow down because of the reduction in the prices of crude oil. Another factor that could hinder growth is high capital investment needed for R&D for developing advanced methods for production of algae. However, the international algae market is envisaged to gather pace in terms of growth as growing application of algae in wastewater treatment generates opportunities for the future. Moreover, continuous increase in industrial activities is predicted to increase the demand in the market. Use of algae for capturing carbon dioxide could act as another opportunity for market growth. Increasing efforts for commercializing biofuel production from algae may help in increasing more demand in the market. Dutch scientists have produced a biopolymer from algae, which could replace synthetic plastics over time. The researchers grow algae, which upon drying and processing into a material, can be used to 3D print objects. According to these scientists, algae polymer could be used to produce everything from shampoo bottles to tableware or dust bins, finally completely replacing plastics produced from fossil fuels such as oil. The products

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are more eco-friendly in comparison to their synthetic counterparts, from fabric dyes and water bottles to chairs and even entire building facades (www.dezeen.com) One of the most interesting products from algae that is being researched is biofuels. However, many algae fuel companies are now exploring algae-based value-added products business, after having started to realize that it could take much longer than originally thought to obtain fuels from algae. A great diversity of metabolites and bioactive compounds are biosynthesized, metabolized, accumulated, and secreted by algae, several of which are valuable materials with potential applications in the food, pharmaceutical, and cosmetics industries. Most of the products obtained from algae need to break into established markets dominated by other, usually petrochemical, feedstocks, and compete with well-established supply chains (www.bbsrc.co.uk; www.repository.utl.pt; snrecmitigation.wordpress.com). Algae contain proteins, carbohydrates, fats, and nucleic acids. Macroalgae contain small amounts of lipid, which function as structural components of the cell membranes, and produce carbohydrates for use as their primary energy storage compound. Conversely, several microalgae produce lipids as the primary storage material. The oil content ranges from 5% to 70%, protein content ranges from 10% to 50%, and carbohydrate content ranges from 25% to 40%. The lipid from algae can be used for biodiesel production and the carbohydrate content of algae can be used for producing ethanol, and the protein can be used as animal feed. Algae are also able to biosynthesize, metabolize, accumulate, and secrete several types of primary and secondary metabolites, several of which are valuable substances with potential applications in various industries (Bajpai, 2018). Several high-value microalgal products are well established in the market place and there are opportunities for many new products. The algal products presently available in the market are specialty products and some “ceuticals.” For microalgae, these include pigments, omega-3 and -6 fatty acids, vitamins, and whole algae as specialty food/feed items and for cosmetics; for macroalgae they encompass specialty food/feed, fertilizers, and hydrocolloids. Some of the emerging algae products include cattle and hog feed, fish feed, nutrition products, chemicals, bioplastics, lubricants, and algae pharmaceuticals (http://www.oilgae.com/ref/wp/downloads/emerging-algae-products-and-businessopportunities.pdf). The global algae biomass market is worth between US$ 5e7 billion. From this total, the health food sector accounts for US $2 billion and the aquaculture applications account for US$ 0.7 billion. There are only two approved omega 3 based pharmaceuticals in the world, which together account for US $1.5 billion sales. Algal products such as Spirulina and Chlorella have significant benefits as potential single cell protein sources. But the market value of these products is not very high; Spirulina was sold at a price of US $20/kg in 2010 and Chlorella at a price of US $44/kg in 2010 (www.oilgae.com/ref/wp/.../emerging-algae-products-andbusiness-opportunities.pdf; www.icis.com/.../news/2010/.../21/.../algae-based-bioplastics-a-fastgrowing-ma).

Emerging sources of biopolymers

A small industry for growing and producing microalgae on an industrial scale has evolved over the past 50 years. “The industry originated with research in USA, Japan, Germany and other countries for food production using microalgae, which led to the first industrial scale production of microalgae for human consumption (nutritional supplements) in Japan in the early 1960s. The microalga produced commercially was Chlorella, which was cultivated in open, circular ponds. Cultivation requires a large volume of inoculum for ensuring purity of the cultures. Harvesting and drying the biomass uses centrifuges and spray dryers, and the cells then need to be broken (typically using ball mills). About 5000 mt of Chlorella biomass, selling for w$20,000/mt (plant gate) is presently being produced worldwide, mainly in Japan and Taiwan. Different types of production systemsdcircular ponds, paddle wheel mixed raceway ponds, tubular photobioreactors and fermentation processesdare being used for producing algae commercially. Some producers using open pond systems and feed the algae acetate, which make them grow faster. Such mixotrophic production has also been recommended for production of biofuels. However, such processes are limited by the relatively high cost of the substrate and problems associated with bacterial consumption of the substrate” (www. energybiosciencesinstitute.org;hub.globalccsinstitute.com/...algae...production/21current-and-potential-uses). Algae are a versatile source of biopolymers. Algae metabolic pathways can be oriented toward the production of specific biopolymers, thanks to adequate strain selection and process optimization. There is still plenty of room for process and product innovation!

References Abe, M., Fukaya, Y., Ohno, H., 2010. Extraction of polysaccharides from bran with phosphonate or phosphinate derived ionic liquids under short mixing time and low temperature. Green Chem. 12, 1274e1280, 2010. Azeem, M., Batool, F., Iqbal, N., Haq, I., 2017. Algal-based biopolymers. In: Zia, K.M., Zuber, M., Ali, M. (Eds.), Algae Based Polymers, Blends, and Composites. Elsevier, USA. Bajpai, P., 2018. Third Generation Biofuels. Springer Briefs in Energy. Springer Nature Singapore Pte Ltd. Gange, A., 2010. Biopolymers in Packaging Applications. IntertechPira, USA. Ibrahim, M., Salman, M., Kamal, S., Rehman, S., Razzaq, A., Akash, S.H., 2017. Algae-Based Biologically Active Compounds. Elsevier BV. Kara, R., 2011. Fungi, Algae and Protists. Britannica Educational Publishing, New York, pp. 89e142, 2011. Laycock, B., Halley, P., Pratt, S., Werker, A., Lant, P., 2013. The chemomechanical properties of microbial polyhydroxyalkanoates. Prog. Polym. Sci. 38, 536e583. Masarin, F., Roberto Paz Cedeno, F., Chavez, E.G.S., Ezequiel de Oliveira, L., Gelli, V.C., Monti, R., 2016. Chemical analysis and biorefinery of red algae Kappaphycus alvarezii for efficient production of glucose from residue of carrageenan extraction process. Biotechnol. Biofuels 9 (122). https://doi.org/ 10.1186/s13068-016-0535-9. Pelczar Jr., M.J., Chan, E.C.S., Kreig, N.R., 1986. Microbiology, fifth ed. National Book Foundation, Islamabad, pp. 365e377. Sassi, J.F., Delrue, F., Peltier, G., Li-Beisson, Y., 2017. In: Algal Biomass as an Alternative Feedstock for Biopolymers, 2nd Workshop “Sweet Microalgae” Grenoble e February 20e24th 2017.

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Sharma, O.P., 2007. Textbook of Algae. Tata Mcgraw-Hill Publishing Company Limited, New Delhi, 2007. Teixeira, R.E., 2012. Energy-efficient extraction of fuel and chemical feedstocks from algae. Green Chem. 14, 419e427. Trivedi, P.S., Pandey, S.N., 2009. A Textbook of Botany, eleventh ed., vol. 1. Vikas Publishing House, India, pp. 367e369. Velde, F., Pereira, L., Rollema, H.S., 2004. The revised NMR chemical shift data of carrageenans. Carbohydr. Res. 339, 2309e2313. Wei, N., Quarterman, J., Jin, Y., 2013. Marine macroalgae: an untapped resource for producing fuels and chemicals. Trends Biotechnol. 31, 2.

Relevant websites chemicalenegry.blogspot.com/2019/01/algae-market-to-surge-at-robust-pace-in.html. www.energybiosciencesinstitute.org;hub.globalccsinstitute.com/...algae...production/21-current-andpotential-uses. www.algae4ab.eu/pdf/dissemination/01_algae4ab_sassi_cea_algal_biopolymers.pdf?. www.ieabioenergy.com/.../Laurens-2017-Renewableenergy-from-algae-perspective.p. www.oilgae.com/ref/wp/downloads/emerging-algae-products-and-business-opportunities.pdf. https://hub.globalccsinstitute.com/...algae...production/21-current-and-potential-uses. www.transparencymarketresearch.com. www.bbsrc.co.uk. www.dezeen.com. www.antoniosonnessa.com. www.ieabioenergy.com. www.icis.com/ ... /news/2010/ ... /21/ ... /algae-based-bioplastics-a-fast-growing-ma. www.repository.utl.pt. snrecmitigation.wordpress.com. www.businesswire.com/news/.../Cereplast-Begins-Bioplastics-Production-Indian.

CHAPTER 11

Emerging technologyd nanotechnology Contents References Further reading Relevant websites

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Nanotechnology is an emerging technology, which involves the characterization, fabrication, and manipulation of structures, devices or materials having a minimum of one dimension having 1e100 nm in length. This technology deals with nanomaterials and nanosystems commonly smaller than 100 nanometers. Nanomaterials are defined as materials with any external dimension on the nanoscale, and are clustered into three categories, namely nanoparticles, nanofibers and nanoplates. Nanocomposites are mixture of polymers of inorganic and inorganic additives having certain geometrics. Duncan, 2011; www.omicsonline.org

Nanotechnology is finding application in several areas (Table 11.1). Currently, several companies are developing nanotechnology for its use in food packaging (Neethirajan and Jayas, 2011). Over 400,000 researchers are working in the area of nanotechnology. Use of nanomaterials of at least 3 trillion US dollars by the year 2020 is predicted (Wesley et al., 2014). Currently, there are more than 40 packaging products based on nanotechnology in the market, in comparison to the 400 traditional products used. Market forecasts for packaging materials consisting of nanostructured compounds appear quite promising (20 billion USD in 2020) (Johansson et al., 2012). Nanotechnology is a cross-sectional technology (used in different production processes of miscellaneous industries) and has the potential to play an important role in the further development of biopolymer-based packaging. Packaging is a relatively large and important application for nanotechnology. Materials produced from nanotechnology provide valuable packaging properties (Gange, 2010). Several properties can be improved by nanotechnology. These include physical properties and barrier and weight properties. Physical properties include tensile strength, heat distortion, modulus, and toughness. By reducing packaging cross-section, significant reductions in weight can be achieved. The inclusion of nanotechnology into bioplastics can result in materials with an improved balance between permeabilities for oxygen, carbon dioxide, nitrogen, and water vapor. This can be obtained by Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00011-4

© 2019 Elsevier Inc. All rights reserved.

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Table 11.1 Diverse applications of nanotechnology. Paper manufacture

Packaging Biomedical Textile Sensor for security system Cosmetics Paints Nanoelectronics Medical and health care Construction material Lubricants Weapons and explosives Batteries Agrochemicals Veterinary medicine Water treatment

homogeneously dispersing functionalized layered silicates (clay minerals) in materials such as thermoplastic starch via polymer melt processing methods. The permeability of oxygen and water vapor can be increased by a factor of more than 10 in such a manner and additional mechanical properties may also be improved. Various studies have shown that within a biopolymer matrix, clay particles can be dispersed on a nanoscale and the biopolymer nanocomposite films can be blown. Packaging products developed from such technology have not been commercialized yet. Currently, the most commercially and technically interesting nanotechnology-based products developed for packaging are polymer nanocomposites. These are polymeric compounds that consist of discrete fillers, a few nanometers in diameter, and with large surface areas. With conventional conversion equipment, these compounds can be processed into film and other packaging materials. Nanocomposites represent a radical alternative to conventional polymers and polymer blends. Nanocomposites are relatively low cost in comparison to other nanomaterials. Low-volume additions (1%e5% wt) of highly anisotropic, high aspect ratio nanoparticles such as layered silicates, provide mechanical property improvements with respect to the virgin biopolymer that are comparable with those obtained by conventional filler loadings of 15%e40%. This results in substantial processing advantages and reduced cost potential because of down gauging of cross-section coatings (Gange, 2010). An interesting property improvement provided by clay nanocomposites, is its low gas permeability. “The first commercial nanocomposites consist of mixtures of nylon or other barrier resin with nanoscale silicate clay particles. The clay particles are in the form of very fine platelets having a thickness of one nanometre. They are chemically treated to make them organophilic so that the polymer will enter the spaces between

Emerging technologydnanotechnology

the platelets. The clay then swells, and the plates spread apart. The result is a nanocomposite which is highly effective in restricting permeation of gases” (www.nigeriafirst.org). Other potential uses include the applications of nanometer-thick films and coatings (Gange, 2010). These can be used as individual barriers in multilayer films or they can be produced from multiple nanometer-thick films. Nanotechnology can be used to produce films or monolayers that range from 1 to 5 nm thickness. These ultrathin films are either organic or inorganic. Microlayer extrusion of several polymers has been conducted, including combinations of different polymers. The microlayer systems have also been combined with the injection molding process for producing structure with platelets of one polymer in another. This results in materials with improved barrier properties. “Toray Industries, Inc. has developed a flexible PLA film using its own nanostructure control technology for biaxially oriented films. The new film avoids the problem associated with PLA of loss of transparency and heat resistance, by obtaining enough flexibility so that it can be used in packaging. But, regulations regarding nanotechnology are still being drawn up in Europe and the European Parliament’s environment committee called for products containing nanotechnology to be removed from the market and re-assessed” (www.antoniosonnessa.com). The Woodrow Wilson International Center for Scholars, Washington, DC, United States, is also examining the regulatory challenges posed by nanotechnologies and examining the effectiveness of existing methods (Gange, 2010). Nanocellulosic materials are suitable for packaging applications because these materials possess good oxygen barrier properties (Fukuzimi et al., 2009; Syverud and Stenius, 2009; Aulin et al., 2010; Bajpai, 2011; Bajpai, 2016). The excellent oxygen barrier properties of nanocellulose are because of its high crystallinity and high cohesive energy density. In the dry state, nanocelluloses have the lowest oxygen permeability of all the studied organic materials (Lindstr€ om et al., 2013a,b). But their hygroscopic properties and moisture sorption limit their performance. The barriers deteriorate at higher relative humidity. A new trend in the packaging industry is to introduce barrier properties to the packaging paper or paperboard by coating it with a barrier coating that is biodegradable. A barrier coating can replace petroleum-based barrier coatings such as extruded polyethylene or coatings that are recycled with difficulty. A barrier coating may replace other barrier layers such as aluminum in laminates. The major challenge in creating a barrier coating is to make a defect-free and evenly thin layer, having good mechanical properties to tolerate the conversion of the material to package and end-use conditions. Nanocellulose can be used for coating of paper. Microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC) have been studied as paper coating (Hult et al., 2010, Song et al., 2010, Iotti et al., 2010, Aulin et al., 2010, Syverud, Stenius, 2009; Hamada et al., 2010). NFC has also been studied for coating on synthetic fiber sheet (Hamada and Bousfield, 2010). Many advantages of this surface treatment have been observed. These include higher strength properties of the coated paper, significant reduction in air permeability, better oxygen

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and oil barrier properties and reduced water vapor transmission rate, prevention of linting in TMP-based paper by increasing the surface strength with MFC-starch coating, and low ink absorption into base paper and high print density for water-based pigmented flexographic inks and ink-jet prints. The reduction in penetration of air and gases through the coated paper is based on the dense surface layer produced by the cellulose fibrils on the paper. The beneficial effects are obtained only by multiple coating layers. Methods used in the coating include a laboratory-scale wire-wound rod coater, spray coater, and dynamic sheet former. In several studies, the nanocellulose coating contains additives or other matrix materials. Thickeners can be used for modifying the processability, the natural resin shellac can be used to ease the processability of the blend, and clay can be used to give NFC either the role of pigment or binder (Hult et al., 2010). Extensive research is being conducted on the use of nanocellulose as a reinforcing filler or barrier-increasing additive in biodegradable composites based on chitosan matrix (Fernandes et al., 2011). Nanotechnologies can improve the mechanical, barrier, and antimicrobial properties of food packaging. The global nano-enabled packaging market was 23.73 billion US dollars in 2015 and is expected to see substantial growth over the next 5 years. The major drivers affecting the demand growth include favorable food safety regulations and increasing demand for effective packaging solutions in the food and beverage and pharmaceutical sectors. The largest market for nanopackaging applications is Japan (Anon, 2009c). The Voronezh State Forest Technical Academy in Russia is developing nanocellulose using the by-products of sugar industry. Potential applications for nanocellulose obtained from sugar beet include paper packaging with high-strength properties, disposable plates, and seed coatings. SCA, Sweden, has used nanotechnology for producing coatings for packaging paper. Other companies are also involved in developing nanotechnology-based paper and paperboard products. These are Stora Enso, in Finland, and Eka Chemical, in Sweden. MFC has been examined for use in packaging materials. Aulin et al. (2010) used two papers having different air permeances (Kraft paper and greaseproof paper) as base paper and coated with MFC for studying the conditions needed for obtaining a packaging material with good oil barrier properties. A sulfite softwood-dissolving pulp was used for producing MFC and a carboxymethylation pretreatment was used instead of enzymatic pretreatment. MFC produced from dissolving pulp is suitable for producing transparent-free films and to coat thin layers on base papers. The MFC films consisted of randomly assembled nanofibers, mostly with a thickness of approximately 5e10 nm. The films were found to possess very low oxygen permeability (OP) values at low relative humidity (RH), but the oxygen transmission rate (OTR) increased with the increase of RH. When the surrounding RH was increased in a humidity scan, the storage modulus of the films reduced. Dense structure produced by the semicrystalline microfibrils and their ability to form intra- and interfibrillar hydrogen bonds contributed to the better barrier properties of the films. MFC coating substantially reduced the air permeability of the coated paper.

Emerging technologydnanotechnology

Papers and paperboard with different air permeances were coated with MFC and shellac for increasing the barrier properties (Hult et al., 2010). The coating materials were applied using conventional methods, for instance, bar coating and spray coating, and the mechanical properties of the coated papers were also examined. Decolored shellac was used and the MFC was produced by disintegration and homogenization of a bleached Kraft pulp. The MFC/shellac combination was examined as a one-layer coating using an MFC/shellac blend and as a multilayer system with MFC as a first layer and shellac as the top layer. The most significant results obtained were a reduction of air, water vapor, and oxygen permeability. The use of MFC coating reduced the air permeability of paper and paperboard. Although the MFC coating would not completely cover the surface, an additional shellac layer actually covered the pinholes, leading to significantly improved barrier. A sufficient oxygen barrier for high barrier packaging was not obtained, although the multilayer coating with MFC and shellac significantly reduced the OTR values. At the same time, the addition of a shellac layer also introduced water vapor barrier, which obtained values considered as high barrier in food packaging. In addition, the adhesion of all the tested blends was good, with the strength between shellac and MFC and the strength between MFC and base paper being at least as strong as the internal bond strength of the paper substrate used. MFC produced from Norway spruce sulfate fibers was modified through surface acetylation with acetic anhydride (Rodionova et al., 2011). The acetylation was confirmed by fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy (XPS), contact angle, and water vapor transfer rate (WVTR) results. Oxygen transmission rate of acetylated MFC films was comparable to those of common packaging materials. No significant changes of the mechanical properties were observed as a result of a long reaction time. Acetylation appears to be a good method for hydrophobization of the MFC surface according to scanning electron microscope images and analyses. Modified MFC films with thickness of 42e47 mm fulfill the requirements for the modified atmosphere packaging oxygen permeability values. Surface acetylation of the MFC appears to be promising hydrophobization reaction for modification of this material and obtaining barrier properties that can be used for sustainable packaging, thus contributing to broadening the application of cellulosic materials in this area. TEMPO-oxidized cellulose nanofibers were produced by Japanese researchers (Isogai et al., 2010). These nanomaterials show high strength, high gas barrier properties, high crystallinity, high transparency, and low coefficient of thermal expansion. Applications for the new bionanofibers produced from bleached Kraft pulps by TEMPO-mediated oxidation include high-tech fields like high-performance and environmentally friendly packaging films, electronic devices, high-performance filters, biofibers in place of asbestos, health care and medical materials, etc.

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Koga (2000) patented a method for producing a gas barrier and moisture-resistant paper laminate containing layers of microfibrillated cellulose. The laminate is found to be suitable for medical and electronic parts and food packaging applications. Low gas permeability is one of the interesting property enhancements from clay nanocomposites, particularly for the packaging industry, with nylon nanocomposites claimed to supply a hundredfold reduction of oxygen permeation and provide a carbon dioxide barrier giving increased shelf life. Applications for nanoclay composites are barrier layers in multilayer polyethylene terephthalate bottles, multilayer flexible films for potato crisps and ketchup, cheese and meat containers, replacement of ethylene vinyl alcohol copolymer in food packaging, and high-density polyethylene containers (Anon, 2009a). Anon (2009b) used a nanotechnology-based product produced from vegetable materials. The product provided a waterproof barrier on a paper surface. It offered a sustainable alternative to the conventional commonly used polyethylene and acrylic resins. This paper was fully recyclable as the product was obtained from a vegetable source. International Paper has developed a technology for gas and moisture barrier for beverage packaging. This technology uses a nanoclay composite coating. Similar types of nanocomposite coatings have also been explored by International Paper in inkjet and digital printing paper (Favier et al., 1995; Grunert and Winter 2002a,b; Azizi Samir et al., 2004a,b). Cellulose nanocrystals function similarly to nanoclays or carbon nanotubes, except that they are available from renewable, raw materials. Rapidly biodegradable hydrophobic material film coatings made of cellulose-latex nanocomposites have been commercialized for use in packaging for improving the dimensional stability, hygroexpansivity, and toughness of sack paper, with application in food packaging (Helbert et al., 1996; Anon, 2009a). Vermiculite nanoplatelets were combined with cellulose nanofibrils (CNF) into functional biohybrid films (Aulin et al., 2012). The oxygen barrier properties of the biohybrid films outperform commercial packaging materials, and pure nanocellulose films showing an oxygen permeability of 0.07 cm3 mm m 2 d 1 kPa 1 at 50% RH. The oxygen transmission rate of pure CNF films can typically be reduced by an order of magnitude with such nanoclay treatments. Cellulose nanomaterials are used for improving strength and weight properties in production of paperboard. Cellulose nanomaterials are expected to improve the fiberefiber bond strength and therefore have a strong reinforcement effect on paper materials while using less cellulose pulp through the thickness (American Forest and Paper Assoc, 2005). The result will be lighter-weight packaging, which reduces fuel cost and consumption associated with transportation. Cellulose nanomaterials are useful as a barrier in grease-proof types of papers and as a wet-end additive for increasing retention of additives, and also dry and wet strength, in commodity types of paper and paperboard products (Aulin et al., 2010). The addition of CNF to coatings also improves ink adhesion to the surface, allowing papers to be lighter and thinner.

Emerging technologydnanotechnology

The properties of the cellulose nanomaterials make them an interesting material for reinforcing plastics. Cellulose nanomaterials improve the performance of, for instance, thermosetting resins, starch-based matrices, soy protein, rubber latex, and poly(lactide) (Yu et al., 2006). The composite applications may be for use as coatings and films, foams, paints, and packaging. Cellulose nanocrystal (CNC) can be aligned to produce tunable optical properties, including transparency color changes. Annual production of paperboard in the United States is 82 million metric tons; and addition of 2%e10% CNF as filler will significantly toughen and strengthen the paper (Cowie et al., 2014). Several types of nanosensors are being used in food packaging. These include nanoparticles-based sensors. Packaging with nanosensors can be used to find the conditions of food products throughout the food supply chain (Pal, 2017). Nanosensors in plastic packaging can diagnose gases in food when it gets spoiled, and the packaging itself changes color to caution the consumer. Moreover, film packed with silicate nanoparticles is able to reduce the flow of oxygen into the package, and leaking of moisture out of package can keep the food fresh. It is able to stop the growth of fungus inside the fridge. Sensors are now available for detecting contamination in the packaged foods. The packaging waste associated with processed foods can be reduced by the use of nanotechnology. This also supports the preservation of fresh foods, thereby increasing their self-life. The current methods used for detecting the pathogens in food products take 2e7 days. Nanotechnology is also used for detection of toxins, pesticides, and spoilage (Wesley et al., 2014). Nanotechnology can be used for producing smart packaging for increasing the shelf life of products (Pal, 2017). Smart packaging containing nanosensors and antimicrobials is being developed for detecting deterioration of food and release of nanoantimicrobials for increasing shelf life. With these technologies, supermarkets can store the food for even longer duration before it is sold (Sekhon, 2010).

References American Forest and Paper Assoc, 2005. Nanotechnology for the Forest Products Industry. Vision and Technology Roadmap. TAPPI Press, Atlanta. Aulin, C., Salazar-Alvarez, G., Lindstr€ om, T., 2012. High strength, flexible and transparent nanofibrillated celluloseenanoclay biohybrid films with tunable oxygen and water vapor permeability. Nanoscale 4 (20), 6622e6628. Anon, 2009a. Nanomater. News E-annual 12, 22. Anon, 2009b. Active intell. Packag. News 8. Anon, 2009c. Nanotechnologies and packaging. Package. Mag. 5, 18e19. Aulin, C., Gallstedt, M., Lindstrom, T., 2010. Oxygen and oil barrier properties of microfibrillated cellulose films and coatings. Cellulose 17 (3), 559e574. June 2010. Azizi Samir, M.A.S., Alloin, F., Gorecki, W., Sanchez, J.Y., Dufresne, A., 2004b. Nanocomposite polymer electrolytes based on poly(oxyethylene) and cellulose nanocrystals. J. Phys. Chem. B 108, 10845e10852. Azizi Samir, M.A.S., Alloin, F., Paillet, M., Dufresne, A., 2004a. Tangling effect in fibrillated cellulose reinforced nanocomposites. Macromolecules 37, 4313e4316. Bajpai, P., 2011. Nanocellulose in Paper and Board. PIRA International, U.K.

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Bajpai, P., 2016. Pulp and paper industry. In: Nanotechnology in Forest Industry, first ed. Elsevier, USA. Cowie, J., Bilek, E.M., Wegner, T.H., Shatkin, J.A., 2014. Market projections of cellulose nanomaterialenabled products e Part 2: volume estimates. TAPPI J. 13 (6), 57e69. Duncan, T.V., 2011. Applications of nanotechnology in food packaging and food safety: barrier materials, antimicrobials and sensors. J. Colloid Interface Sci. 363, 1e24. Favier, V., Chanzy, H., Cavaille, J.Y., 1995. Polymer nanocomposites reinforced by cellulose whiskers. Marcomolecules 28, 6365. Fernandes, S.C.M., Freire, C.S.R., Silvestre, A.J.D., Pascoal Neto, C., Gandini, A., 2011. Novel materials based on chitosan and cellulose. Polym. Int. 60 (6), 875e882. Fukuzumi, H., Saito, T., Wata, T., Kumamoto, Y., Isogai, A., 2009. Transparent and high gas barrier films of cellulose nanofibers prepared by TEMPO-mediated oxidation. Biomacromolecules 10, 162e165. Gange, A., 2010. Biopolymers in Packaging Applications. IntertechPira, USA. Grunert, M., Winter, W.T., 2002a. Nanocomposites of cellulose acetate butyrate reinforced with cellulose nanocrystals. J. Polym. Environ. 10, 27e30. Grunert, M., Winter, W.T., 2002b. Cellulose nanocrystal reinforced acetate butyrate reinforced with cellulose nanocrystals. Polym. Material Sci. Engg. 86, 367e368. Hamada, H., Beckvermit, J., Bousfield, D.W., 2010. Nanofibrillated cellulose with fine clay as a coating agent. In: 77th Pulp and Paper Research Conference, Tokyo, Japan, 17e18 June 2010, pp. 36e41. Hamada, H., Bousfield, D.W., 2010. Nanofibrillated cellulose as a coating agent to improve print quality of synthetic fiber sheets. TAPPI J. 9 (11), 25e29. Helbert, W., Cavaille, J.Y., Dufresne, A., 1996. Thermoplastic nanocomposites filled with wheat straw cellulose whiskers. Part I: processing and mechanical behavior. Polym. Compos. 17 (4), 604e611. Hult, E.-L., Iotti, M., Lenes, M., 2010. Efficient approach to high barrier packaging using microfibrillar cellulose and shellac. Cellulose 17 (3), 575e586. June 2010. Iotti, M., Eriksen, Ø., Gregersen, Ø., Lenes, M., 2010. Semi industrial application of MFC barrier coating, a rheological and technological study. In: Paper Presented at the International Conference on Nanotechnology for the Forest Products Industry 2010. Isogai, A., Saito, T., Fukuzumi, H., Okita, Y., Isogai, T., 2010. In: Development of Advanced New Bio-Nanofibres from Wood Pulp: Preparation and Application of TEMPO-Oxidized Cellulose Nanofibres, 64th Appita Annual Conference and Exhibition, 18e21 April 2010, Melbourne, Australia, pp. 41e46. Johansson, C., Bras, J., Mondragon, I., Nechita, P., Plackett, D., Simon, P., Svetec, D.G., Virtanen, S., Baschetti, M.G., Breen, C., Clegg, F., Aucejo, S., 2012. Renewable fibers and bio-based materials forpackaging applications - a review of recent developments. BioResources 7 (2), 2506e2552. Koga, S., 2000. Gas-barrier and Moisture-resistant Paper Laminate. Jpn Kokai Tokkyo Koho 99-110576:7. Lindstr€ om, T., Ankerfors, M., Aulin, C., 2013a. Nanofibrillated cellulose (NFC) e an emerging material for large-scale applications. In: Paper Presented at: NanoTech, May 2013; Washington, DC. Lindstr€ om, T., Aulin, C., Naderi, A., Ankerfors, M., 2013b. Microfibrillar Cellulose. Encyclopedia of Polymer Science and Technology. Wiley, Chichester (UK). Neethirajan, S., Jayas, D.S., 2011. Nanotechnology for the food and bioprocessing industries. Food Bioprocess Technol. 4, 39e47. Pal, M., 2017. Nanotechnology: a new approach in food packaging. J Food Microbiol. Saf. Hyg. 2, 121. https://doi.org/10.4172/2476-2059.1000121. Rodionova, G., Lenes, M., Eriksen, O., Gregersen, O., 2011. Surface chemical modification of microfibrillated cellulose: improvement of barrier properties for packaging Applications. Cellulose 18, 127e134. Sekhon, B.S., 2010. Food nanotechnology- an overview. Nanotechnol. Sci. Appl. 3, 1e15. Song, H., Ankerfors, M., Hoc, M., Lindstr€ om, T., 2010. Reduction of the linting and dusting propencity of newspaper using starch and microfibrillated cellulose. Nord. Pulp Pap Res. J. 25 (4), 519e528. Syverud, K., Stenius, P., 2009. Strength and barrier properties of MFC films. Cellulose 16, 75e85. Wesley, S.J., Raja, P., Sunder Raj, A.A., Tiroutchelvamae, D., 2014. Review on- Nanotechnology applications in food packaging and safety. Int. J. Eng. Res. 3, 645e651. Yu, L., Dean, K., Li, L., 2006. Polymer blends and composites from renewable resources. Prog. Polym. Sci. 31 (6), 576e602.

Emerging technologydnanotechnology

Further reading Anon, 1983a. Strengthening of paper. Jpn Kokai Tokkyo Koho 82-79609:4. Hult, A., 2008. Surface grafting of microfibrillated cellulose with poly(e-caprolactone)dsynthesis and characterization. Eur. Polym. J. 44, 2991e2997.

Relevant websites www.omicsonline.org. www.nigeriafirst.org. www.antoniosonnessa.com.

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Future prospects Contents References Further reading Relevant websites

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“Bio-based polymer industry is catching up with fossil fuel based chemical industry, that has increased within the last two decades” (Babu et al., 2013). The production of biobased materials from renewable raw materials has become a reality due to the advancements in white biotechnology. Many countries are conducting extensive R&D in the area of biobased packaging materials. Future prospects of biobased polymers/materials appear to be bright. Biorefinery productsdmaterials produced from wood; regenerated cellulose from wood or plant sourcesdhave attracted considerable research attention in the last few years and this trend is likely to continue (Weber, 2000). “Multilayers of biobased coatings and combinations of biobased- and inorganic layers and/or synthetic barriers for improving the functionality may become important solutions in future. Market forecasts and trends are opening new perspectives for biobased materials as alternatives in the packaging industry. Customers are looking for eco-solutions on the market and studies of consumer behavior indicate that consumers are willing to pay more for environmentally friendly products” (www.cellulosechemtechnol.ro/pdf/CCT7-8(2015)/p. 709-713.pdf). In the future, the costs for biobased materials are likely to reduce because of the increased availability of raw materials and higher production capability and efficiency. Horizon 2020 is offering an opportunity that should be used for developing the budding technologies and continue to refine products from renewable raw materials (www.cellulosechemtechnol.ro/pdf/CCT7-8(2015)/p.709-713.pdf). Challenges that should be addressed in the future comprise of raw material management, cost of production, and performance of biobased polymers. Economy of scale will be the major challenge for production of biomonomers and polymers from sustainable raw materials (paperity.org). Manufacturing large-size plants is not easy because the experience in new technologies and estimation of supply/demand balance is missing. For making these technologies cost-effective, it is vital to develop the following: • Logistics for biomass substrate • New routes for manufacturing by replacing existing methods with high yields • New strains of microorganisms/enzymes • Efficient strategies for downstream processing for recovery of biomaterials Biobased Polymers ISBN 978-0-12-818404-2, https://doi.org/10.1016/B978-0-12-818404-2.00012-6

© 2019 Elsevier Inc. All rights reserved.

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Biobased industry focuses on bioconversions of monomers and polymers (paperity.org). The performance of these products is good. The existing products can be replaced relatively easier with performance matching with that of bioversions. The properties of these materials/polymers is comparable to that of fossil-based polymers. In recent years, several efforts have been made to use new biobased polymers/materials showing better performance. For instance, in the United States, Nature Works LLC has developed new varieties of polylactic acid having better thermal and mechanical properties (Babu et al., 2013). New polylactic acid -tri block copolymers perform like thermoplastic elastomer. Efforts are being made to develop various polyhydroxyalkanoates (PHAs), polyesters, and polyamides, etc. having different final properties for use in several industrial applications. The problem with some of these biopolymers/materials is that they cannot be processed in the equipment currently being used. “Extensive information is available on additive-based chemistry developed for improving the performance and processing of fossil fuel-based polymers, and this knowledge can be used for developing new additive chemistry for improving the performance of bio-based polymers” (Ray and Bousmina, 2005). Additives have been developed to improve the performance of a few biobased polymers like polylactic acid and PHAs, by developing new copolymers or mixing with other polymers. But, the additive market for biopolymers is not big (link. springer.com). The justification of developmental efforts becomes difficult according to some major suppliers. Nanoparticles have been used for improving the performance of polymers produced from petroleum. Various nanoreinforcements have been developed. These comprise “cellulose nanowhiskers, carbon nanotubes, graphene, nanoclays and 2-D layered materials. When these nanofillers are combined with bio-based polymers, a large number of physical properties such as barrier, flame resistance, thermal stability, solvent uptake, biodegradability rate, relative to unmodified polymer resin could be improved. These improvements are usually achieved at low filler content” (Babu et al., 2013). Nanoreinforcement is a promising route for producing new biomaterials for many applications. Biobased polymers are now being produced on a commercial scale but, there are many factors that should be considered for their viability on a long term (paperity.org). The worldwide demand for food and energy is increasing. Therefore, the feedstock competition would also increase. The renewable substrates currently being used for producing biobased polymers/materials usually compete with food-based products. “The production of first-generation bio-fuel will place unfeasible demands on biomass resources and will be a threat to the sustainability of biopolymer production as it is to food production. Indeed the European commission has changed its targets downwards for first-generation biofuels since October 2012, showing its preference for nonfood sources of sugar for biofuel production” (EurActiv.com 2012). Efforts have been made for using cellulose-based substrates for producing sugars for biopolymers (Jong et al., 2010).

Future prospects

Biobased polymers are getting closer to the reality of replacing conventional polymeric materials than ever before. Currently these materials are generally used in several areas from commodity to advanced applications, thanks to developments in the area of biotechnology and public awareness. But, in spite of these developments, there are some disadvantages that prevent the wider use of biomaterials (paperity.org). The increased use of sustainable packaging products by retailers will increase replacement of non-renewable packaging materials with renewable ones. Manufacturers adopting biodegradable packaging materials will benefit through cost and tax reductions. Initiatives by governments of many countries, promoting the use of sustainable packaging materials are encouraging retailers and intermediaries to adopt biodegradable materials for packaging purposes. Growing consumer awareness and the increasing use of biodegradable packaging materials in retail outlets have a favorable impact on the global biodegradable packaging materials market. Increased consumer spending and rising consumer demand for fresh and minimally processed food and beverages are also boosting the demand for biodegradable packaging materials such as bioplastics and paper. (https://www.packworld.com/.../sustainability/...biodegrade/futurebiodegradable-paper)

At the present time, there are two major issues preventing the growth of sustainable polymers. The first is that the water vapor barrier offered by a biodegradable polymer is not as effective as the one offered by low-density polyethylene material. The second issue is that biobased, biodegradable packaging materials are more expensive to produce in comparison to fossil-based polymers. There are other options that are greener than fossil-based polymers. Biobased, nonbiodegradable plastics offer reduced carbon footprint and good performance at a reasonably competitive price. Nanotechnology is playing a crucial role in filling the gaps of packaging material developments in the areas of active and intelligent packaging. But, the major problem with nanomaterials is that they migrate into food, which may result in deleterious health effects (Mihindukulasuriya and Lim, 2014; Echegoyen and Nerin, 2013). Some nanoparticles may cause vascular disease, pulmonary inflammation, and intracellular damages (Brown et al., 2000; Das et al., 2008; Nemmar et al., 2002; Oberdorster et al., 1994). The health and safety properties of several nanomaterials are not known completely. Therefore, food safety must be the major issue during the use of nanomaterials in food packaging. Detailed toxicological studies are required for finding out the risks involved. Food regulations have been established for protecting the consumers from forced exposure to risk. The compounds migrating from packaging material to the food should be investigated in accordance with the European regulation act (Mihindukulasuriya and Lim, 2014; Kruijf et al., 2002). Further, the European Food Safety Authority has instructed that compounds used in packaging should not be harmful to human beings. The compounds released or absorbed should not delude the consumer (De Jong et al., 2005). The European act and US Food and Drug Administration regulations establish the maximum amount of the nanoparticles that can be present in the food (Chaudhry et al., 2008).

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But, precise methods for detection and quantification of nanomaterials migrating from packaging are not available. Therefore, imposing the regulations will be in vain. “When using nanomaterials in food packaging application, due to the requirement of regulatory approval, companies should work jointly with government agencies for making sure that the regulatory requirements are fulfilled” (Mihindukulasuriya and Lim, 2014; Brody et al., 2011). “The other concern associated in nanotechnology developments of packaging system is cost effectiveness. The inclusion of intelligent packaging would increase the cost, particularly during the introduction of the product in the early phase. The profit margin of food is lower in comparison to other consumer products. The packaging cost should be 10% of the product cost” (Dainelli et al., 2008). So, for justifying the application, the use of nanotechnology must be based on cost-benefit analyses (Mihindukulasuriya and Lim, 2014; Restuccia et al., 2010). Another area that companies should take into account is consumer acceptance. The “nanophobia” of consumers for new nanotechnologies may result in poor acceptance, although these technologies may help improve the safety and quality of the food products. Perspectives of consumers toward nanotechnology are dependent on demographic and marketplace. Consumers in a few countries are ready to accept new technologies but in other countries seem to be less receptive to new developments. “Nanotechnology would curb the challenges associated with packaging materials. This will have a positive effect on the quality, safety, and shelf-life, of foods. This will eventually benefit both the producers as well as consumers. But, more R&D is required, particularly on the migration of nanomaterials in food and their impacts on environment, health and safety. A sustainable packaging solution can be obtained only if it is economically viable, and environmentally sustainable” (Mihindukulasuriya and Lim, 2014).

References Babu, R.P., O’Connor, K., Seeram, R., 2013. Current progress on biobased polymers and their future trends. Prog. Biomater. 2 (8), 1e16. Brody, A.L., Zhuang, H., Han, J.H., 2011. Modified Atmosphere Packaging for Fresh-cut Fruits and Vegetables. Wiley-Blackwell, Ames, Iowa, USA. Brown, D.M., Stone, V., Findlay, P., MacNee, W., Donaldson, K., 2000. Increased inflammation and intracellular calcium caused by ultrafine carbon black is independent of transition metals or other soluble components. Occup. Environ. Med. 57, 685e691. Chaudhry, Q., Scotter, M., Blackburn, J., Ross, B., Boxall, A., Castle, L., Aitken, R., Watkins, R., 2008. Applications and implications of nanotechnologies for the food sector. Food Addit. Contam. 25, 241e258. Dainelli, D., Gontard, N., Spyropoulos, D., Zondervan-van den Beuken, E., Tobback, P., 2008. Active and intelligent food packaging: legal aspects and safety concerns. Trends Food Sci. Tech. 19, 103e112. Das, M., Saxena, N., Dwivedi, P.D., 2008. Emerging trends of nanoparticles application in food technology: safety paradigms. Nanotoxicology 3, 10e18. De Jong, A.R., Boumans, H., Slaghek, T., Van Veen, J., Rijk, R., Van Zandvoort, M., 2005. Active and intelligent packaging for food: is it the future? Food Addit. Contam. 22, 975e979.

Future prospects

Echegoyen, Y., Nerin, C., 2013. Nanoparticle release from nanosilver antimicrobial food containers. Food Chem. Toxicol. 62, 16e22. EurActivcom, 2012. EU Calls Time on First-Generation Biofuels. http://www.euractiv.com/climateenvironment/eu-signals-generation-biofuels-news-515496. Jong, E.D., Higson, A., Walsh, P., Maria, W., 2010. Biobased chemicals: value added products from biorefineries. IEA Bioenergy Task 42, 1e34. Biorefinery. http://www.iea-bioenergy.task42biorefineries.com/publications/reports/?. Kruijf, N.D., Beest, M.V., Rijk, R., Sipilainen-Malm, T., Losada, P.P., Meulenaer, B.D., 2002. Active and intelligent packaging: applications and regulatory aspects. Food Addit. Contam. 19, 144e162. Mihindukulasuriya, S.D.F., Lim, L.T., 2014. Nanotechnology development in food packaging: A review. Trends Food Sci. Technol. 40, 149e167. Nemmar, A., Hoet, P.H.M., Vanquickenborne, B., Dinsdale, D., Thomeer, M., Hoylaerts, M.F., Vanbilloen, H., Mortelmans, L., Nemery, B., 2002. Passage of inhaled particles into the blood circulation in humans. Circulation 105, 411e414. Oberdorster, G., Ferin, J., Lehnert, B.E., 1994. Correlation between particle size, in vivo particle persistence, and lung injury. Environ. Health Perspect. 102, 173. Ray, S.S., Bousmina, M., 2005. Biodegradable polymers and their layered silicate nanocomposites: in greening the 21st century materials world. Prog. Mater. Sci. 50, 962e1079. Restuccia, D., Spizzirri, U.G., Parisi, O.I., Cirillo, G., Curcio, M., Iemma, F., Puoci, F., Vinci, G., Picci, N., 2010. New EU regulation aspects and global market of active and intelligent packaging for food industry applications. Food Control 21, 1425e1435. Weber, C. (Ed.), 2000. Biobased Packaging Materials for the Food Industry, Status and Perspectives. The Royal Veterinary and Agricultural University, Frederiksberg, Denmark, ISBN 87-90504-07-0.

Further reading Gange, A., 2010. Biopolymers in Packaging Applications. IntertechPira, USA. Pal, M., 2017. Nanotechnology: A New Approach in Food Packaging. J Food Microbiol Saf Hyg 2, 121. https://doi.org/10.4172/2476-2059.1000121.

Relevant websites www.cellulosechemtechnol.ro/pdf/CCT7-8(2015)/p.709-713.pdf. paperity.org. link.springer.com. www.packworld.com/.../sustainability/...biodegrade/future-biodegradable-paper. EurActiv.com 2012.

217

Index ‘Note: Page numbers followed by “f ” indicate figures and “t” indicate tables.’

A Absorbent, 144e145, 147e149 Acetaldehyde, 76 Acetobacter, 38e39 Acetylated pectin, 56e57 Acetylation, 41, 207 Acetylene, 81 Acidification, 177 Acoustic diaphragm, 36 Acrylic hybrid latexes, 19 Activated carbon, 147e149 Activated clays, 147e149 Activated zeolites, 153t Active packaging antimicrobial packaging, 146e147 antioxidant release, 151 carbon dioxide absorbers, 145 emitters, 145 commercial active packaging systems, 153t ethanol emitters, 149e150 ethylene scavengers, 149 examples, 143t flavor/odor absorbers, 150e151 moisture absorbers, 147e149 other active packaging systems, 152 oxygen scavengers, 142e145 scavengers, 141e142 temperature-controlled packaging, 151e152 uses of, 141e142 Adhesives, 30e31, 37, 63, 88, 113, 185t Adipic acid, 81 Aesthetic, 144t Agaricus blazei, 57 Agaricus blazei murell, 57 Aggregating agent, 44e45 Agricultural crop, 6 Agricultural mulch film, 31 Agriculture, 41, 52, 55, 72e73, 80, 82, 84, 86, 195 Agrobacterium, 38 Agrobar, 3 Agrochemicals, 178 Alcaligenes eutrophus, 86

Alcoholic drink, 46e47 Alcohol-soluble proteins, 66e67 Algae-based plastics, 197 Algae pharmaceuticals, 200 Algal cellulose, 38 Alginates, 45e47, 45f Aliphatic polyester, 8e9, 15, 72e73, 79 Alloys, 185t, 188te189t Allyl isothiocyanate, 146 1,4-alpha-D glucopyranosyl unit, 8e9, 55e56 1/2-a-L-rhamno- pyranosyl unit, 55e56 Aluminum foil, 123 Amorphous, 34, 77 Amphiphilic, 61 Amylomaize, 27e29 Amylopectin, 28 Amylopectins, 27, 28f Amylose, 27e28, 27f Angiogenesis, 60 Anisotropic, 203e205 Anticancer agent, 57 Antifungal, 4e5, 43e44 Antifungal properties, 43e44 Antimicrobial activity, 79 Antimicrobial agent, 49, 66, 79, 144, 146e147, 149 Antimicrobial functionalities, 3, 66 Antimicrobial nanoparticles, 66 Antimicrobial packaging, 79, 146e147 Antimicrobial properties, 1, 41e42, 66, 141e142, 146e147, 206 Antioxidant, 4e5, 60, 65e66, 147, 151 Antioxidant release, 151 Apple pectin, 55e56 Ascorbic acid, 144 Ascorbic acid oxidation, 148t Asparagine, 61 Aspect ratio, 203e205 Atmospheric packaging, 126e127 Aureobasidium pullulans, 42e43 Automotive, 75e76, 80, 84, 195 Azeotropic dehydrative condensation, 73 Azotobacter, 45

219

220

Index

B Bacillus megaterium, 84e86 Bacteria, 8e9, 14, 26, 33e34, 36, 38e39, 45e47, 51e54, 57e58, 84e88, 133e134, 146e147, 149 Bacterial cellulose, 35e36, 38e39 Bacterial cellulose membrane, 161 Bactericidal activity, 66 Bacteriocins, 79 Bakery, 55, 59, 136e137, 194 Baker yeast, 58 Bakery products, 137, 144, 146e147, 149e150 Barley, 27 Barrier coating, 3, 14e15, 42, 205e206 Barrier properties, 2e6, 8e9, 17e19, 29, 36e37, 41e44, 47, 65e71, 88, 115, 123, 130, 132e134, 147, 191, 193, 205e208 Batteries, 158e159 Belu Natural Mineral Water (UK), 133 Benzoate, 65e66 Beta-D-galactopyranosyl residue, 55e56 Beta-D-glucopyranose, 34 Beta-D-mannuronic acid, 46e47 Beta-1,3-glucan, 57 Beta-1,3/1,6-glycan, 57 Beta- (1,4)-glycosidic bond, 33e34, 45 Beta-(1,4) glycosidic linkage, 34 Beta-hydroxyvaleric acid, 88 Beta-1,4-linked GlcN, 39 Beverage bottles, 116 Beverage packaging biopolymer-based bottles, 132e133 carbonated beverages, 132 commercial demands, 132 consumer demands, 132 noncarbonated beverages, 132 polyethylene terephthalate (PET), 132e133 b-Glycans, 57 Binder, 37e38, 44e45, 56e57, 88, 205e206 Bioactive agents, 146e147 Bioactive compound, 65, 200 Bioactive packaging material, 65 Bioactivity, 41 Bioamber, 80 Biobased monomers polymers from biopolyethylene, 82e84 polybutylene succinate, 79e82

polyhydroxyalkanoates, 84e89 polylactic acid, 72e79 Biobased natural polymers alginates, 45e47, 45f carrageenan, 47e50, 48f casein, 68e70 cellulose, 33e39 chitin and chitosan, 39e42, 40f collagen, 59e60 dextrans, 52e55 gelatin, 60e62 gellan, 58e59 glucans, 57e58 gluten, 70e72 pectin, 55e57 pullulan, 42e45 soy protein, 63e65 starch, 26e33 whey protein, 65e66 xanthan, 50e52 zein, 66e68 Biobased packaging material, 5e6 biobased natural polymers alginates, 45e47, 45f carrageenan, 47e50, 48f casein, 68e70 cellulose, 33e39 chitin and chitosan, 39e42, 40f collagen, 59e60 dextrans, 52e55 gelatin, 60e62 gellan, 58e59 glucans, 57e58 gluten, 70e72 pectin, 55e57 pullulan, 42e45 soy protein, 63e65 starch, 26e33 whey protein, 65e66 xanthan, 50e52 zein, 66e68 biobased polymers, 25e26, 26t polymers from biobased monomers biopolyethylene, 82e84 polybutylene succinate, 79e82 polyhydroxyalkanoates, 84e89 polylactic acid, 72e79 Biobased polyethylene, 15 Biocompatibility, 7e8

Index

Biocomposite, 19, 131 Biodegradability, 7e8, 67 Biodegradable materials, 31 Biodegradable packaging, 116 Biodegradable plastics, 68 Biodegradable polymers, 16 Biodegradable polypropylene, 130e131 Biodegradable/recycled materials, 118e122 Biodegradation, 16 Bioethanol, 7, 83e84, 195e196 Biogenic carbon, 171 Biological process, 60, 142, 160 Biomaterial, 3, 6, 8e9, 29, 41, 46e47, 59, 84e85, 184, 213e215 Biomedical implant materials, 88 Biomethanization, 6 Biopackaging materials, 18e19 Bioplastics environmental impact of, 18 European Bioplastics Association, 13 natural polymers, 14e15 types, 13, 14t Biopolyesters, 72 Biopolyethylene, 82e84 Biopolyethylene terephthalate, 14t, 195 Biopolymer-based bottles, 132e133 Biopolymer films, 4e5 Biopolymers, 2, 7, 25e26 cellophane, 16 challenges, 17e18 ecofriendly, 16 manufacturers, 15t packaging, 18e19 paper-coating formulations, 19 types, 15 Bio-polypropylene, 84 Bio-polyvinyl chloride, 84 Biorefinery products, 213 Biosuccinate, 81e82 Bipolymer-based cellulose acetate, 35e36 Blood compatible, 43e44 Blood plasma, 43 Bloom, 62 Bone plates, 89 Bormioli Rocco Plastics (Italy), 135 Bovine hide, 59 Breathability, 1 Brightening agent, 118e122 Brine, 118e122

Brown algae, 45 Bulking agent, 43e44 Butanediol, 81e82 Butylated hydroxytoluene, 141e142, 151

C Calcium oxide, 147e149 Candy wraps, 76 Cans, 113, 193e194 Carbonated beverages, 132 Carbonated drinks, 114 Carbonated soft drink bottles, 116 Carbon dioxide absorbers, 145 emitters, 145 Carbon dioxide emitter, 143t Carbon dioxide scavenger, 143t, 145, 147e149 Carbon disulfide, 35 Carbon footprint, 17 Carboxymethyl, 36, 37t, 147e149 Carboxymethylation, 206 Cardboard, 118 Cardiovascular patches, 89 Carnauba wax, 18e19 Carrageenan, 47e50, 48f Casein, 68e70 Casein packaging, 69e70 Cassava, 27 Cationic property, 41e42 Cattle bone, 59 Cattle feed, 200 Cell adhesion, 60 Cell migration, 60 Cellular phones, 77 Cellulose, 3, 6e8, 14, 16, 26, 33e39, 34f, 37t, 42, 46e47, 50e51, 129e132, 147e150, 161, 184, 187, 197, 205e209, 213 Cellulose acetate, 35e37 Cellulose-based thread, 35 Cellulose derivatives, 35e38, 37t Cellulose diacetate film, 118e122 Cellulose film, 130 Cellulose membrane, 37e38, 161 Cellulose microfibril, 34 Cellulose nanomaterials, 208 Cell wall, 34e35, 39, 45, 55e58 Cement bags, 137 Ceramics, 37, 46e47, 67e68, 187 Ceuticals, 200

221

222

Index

Cheese industry, 65 Cheese spread, 52 Chelating agents, 79 Chemicals, 2, 7e8, 14e17, 29e31, 33, 35, 39e41, 43e45, 49e52, 54, 63, 71e89, 73f, 117e118, 129, 139e140, 142e144, 146, 154e157, 160, 171e174, 176e177, 184, 187, 195e196, 198e200 Chewing gum, 67e68 Chitin, 39e42, 40f Chitosan, 39e42, 40f Chitosan nanoparticle, 40e41 Chlorella, 200e201 Chlorine dioxide, 146e147 Chloroalcohols, 39e40 Circular ponds, 201 Citrus juices, 150 Cladophora, 38 Clay minerals, 203e205 Clay particles, 203e205 Clear-gel toothpaste, 52 Climate change, 171, 173, 175, 177 CMC, 37 Coating, 2e3, 14e15, 18e19, 184e186, 193e194, 205e206 Coffee capsules, 80 Collagen, 59e60 Colloidally stable, 43e44 Colloidal stabilizer, 56e57 Colorimetric sensing, 161 Commercial active packaging systems, 153t Commercial intelligent packaging systems, 161, 161te163t Composite film, 19 Compostable materials, 6, 137 Compost bag, 31, 82 Condensation, 73e74, 81, 147e149 Condensation polymerization, 81 Confectionery sector, 118e122 Confectionery trays, 130 Construction, 32, 34e36, 38, 80, 133e134, 195 Construction material, 35 Consumer Goods, 80, 117, 125e126, 131 Contact angle, 46e47 Containers, 2, 32, 35e36, 78, 84, 113e114, 118e125, 124t, 130, 132, 136e137, 140, 144e145, 152, 154e155, 183, 193e194, 208

Contamination, 6, 69, 133, 139e140, 145e146, 184e185, 209 Controlled Release, 123, 126e127, 151 Conventional resources, 171e172 Cooling Packs, 151e152 Copolyamide, 196 Copolymer, 8e9, 14, 16, 46e47, 74e75, 81, 84e88, 147e150, 208, 214 Copolymer poly(3HB-co-3HV), 88 Cork, 185t, 188te189t Corn, 27 Cornstarch, 30e31 Corn zein protein coatings, 67 Cosmetic Products, 37, 41 Cosmetics, 32, 37, 39, 41, 45, 48e49, 52, 59, 62, 67e68, 84, 88, 118e122, 135, 171, 200 Cotton, 33e36 Cotton fiber, 38 Counterfeit Protection, 158 Covalent Bond, 34, 55e56 Cradle-To-Factory, 176 Cradle-to-gate basis biopolymers, 174 Cradle To Grave, 16, 172 Cross-Linking Agent, 60 Crystalline, 27e28, 31, 33e34, 36e37, 77 Crystallinity, 29, 42, 75, 77, 81, 86, 88, 205, 207 Cupriavidus necator, 85e86 Cyanobacteria, 197e198 Cyclodextrin, 141e142, 151 Cytotoxicity, 60

D Dairy industry, 68e70 Data carriers, 158e160 barcodes, 158 radiofrequency identification (RFID), 158e160 Deacetylation, 41 Debittering, 150 Defrosting, 154 Degradable, 16e17, 31, 69, 78 Degree of crystallinity, 81 Degree of polymerization, 34, 44e45 Demineralization, 41 Dental impression material, 46e47 Depolymerase enzymes, 86 Deproteination, 41 Desiccants, 147e149 Desserts, 52, 62, 137 Detergent refill packs, 120t

Index

Dextrans, 52e55 D-glucopyranosyl, 53f D-glucose, 34, 52e53, 58 D-glucuronic acid, 58 Diagnostic imaging, 43e45 Dietary fiber, 49 Dietary supplement, 45 Direct condensation polymerization, 73 Dispersion coating, 2 Dissolving pulp, 206 Doneness indicators, 161 Drilling mud, 52 Drip absorbent pads, 144e145, 147e149 Drop-in replacement, 84 Drug, 38, 43e47, 52, 54, 60, 89 Drug delivery, 43e44, 46e47, 54, 60, 89 Drug release, 52 D-Sorbitol, 151 Durapulp, 131

E Ecofriendly polymers, 16 Ecological safety, 7e8 Edibility, 144t Edible packaging film, 57 EDTA, 79 Elasticity, 68e71 Elastic properties, 43e44 Electrochemical synthesis, 81e82 Electronics, 3e5, 80, 158e159 Electron microscopy, 34e35, 42 Emulsifier, 46e47, 49, 51e52, 56e57, 59, 61 Encapsulated vitamin, 65 Environmental impact biobased materials, 171 conventional resources, 171e172 cradle-to-gate basis biopolymers, 174 fossil fuel, 177 GHG emissions, 172, 174e175, 177f global warming potential (GWP), 175 life cycle (LCA) methodology, 172 methane, 174 nonrenewable resources, 171e172 polyethylene furandicarboxylate (PEF), 175 polyhydroxyalkanoate (PHA), 175 small-scale pilot plants, 177 technological innovation, 174e175 thermoplastic starch (TPS), 175

Enzycoat, 3 Enzyme oxidation, 148t Enzymes, 8e9, 16e17, 34, 41, 44e45, 52e53, 65e66, 79, 86e87, 147, 150, 171 Enzyme technology, 144 Escherichia coli, 79 Essential amino acids, 66 Essential oil, 79, 141e142, 146 Esterification, 56e57 Ethanol, 83 Ethanol emitters, 143t, 149e150 Ethyl alcohol, 146 Ethylene, 83e84, 140e141, 149, 175, 208 Ethylene scavengers, 143t, 149, 153t Ethylene vinyl alcohol copolymer, 208 Ethylene vinyl alcohol polymers, 140e141 Ethyl vinyl acetate copolymer, 150 European Food Safety Authority, 215e216 European Union (EU), 1 Eutrophication, 172, 174e175, 177e178 Exoskeleton, 39 Expanded polystyrene (EPS), 114 Explosive, 37t, 204t Extensibility, 70e71 Extrusion, 3, 35, 66e67, 70e71, 79, 88, 118e122, 205

F Fats, 2, 42, 150e151, 200 FCMs. See Food contact materials (FCMs) Fermentation, 26, 38e39, 41, 43, 50e51, 54, 58, 72e73, 80e88, 171, 201 Fermenter, 38e39 Fertilizers, 44e45, 178, 200 Fiber, 3e5, 33e35, 37e39, 42, 44e45, 49, 131e132, 136, 171, 173e175, 192, 197, 205e208 Fiber-based packaging, 1e2 Filler, 4e5, 33, 203e206, 209, 214 Film composites, 118e122 Film-forming material, 61 Film plasticizers, 70e71 Films packaging, 117e127 Fishery, 80 Fish feed, 200 Fishing nets, 80 Flame retardancy, 76e77 Flammability, 4e5 Flavonoid, 65

223

224

Index

Flavor absorbers, 144e145, 150 Flavor/odor absorbers, 150e151 Flexible film, 78, 119t, 130, 144e145, 208 Flexible packaging, 117e127, 119t, 120f, 120t, 124t, 126t advantages, 123, 124t aluminum foil, 123 biodegradable and recycled materials, 118e122 film composites, 118e122 innovation, 125 manufacturers, 126, 126t materials, 118, 120t paper-based packaging, 117e118 plastic packaging, 118, 120t precycling benefits, 124e125 styrene-acrylonitrile, 123 technological developments, 117e118 types, 118, 119t Flexural properties, 68 Flocculant, 43 Flocculating agent, 44e45 Fluorimetric detection, 161 Flushable hygiene products, 80 Foaming agent, 52 Food additive, 43e44, 50e51, 186 Food applications, 27, 32, 42, 54e55, 58, 75e76, 118e122, 147e149, 191 Food Biopack project, 3 Food chain, 31, 69 Food contact materials (FCMs) environmental impacts of packaging, 186 EU legislation, 186e187, 188te189t European Food Safety Authority (EFSA), 183, 186 food contamination, 184 food packaging regulations, 186 generally recognized as safe (GRAS), 186 good manufacturing practice (GMP) guidelines, 184 packaging, 183 plastic regulations, 185e186 Regulation 1935/2004, 187 Regulation 2023/2006, 187 Regulation (EC) 1935/2004, 187 Regulation (EC) 2023/2006, 187 Regulation (EC) No 1935/2004, 187 safety, 183 safety of packaging material, 186 types, 185, 185t

Food grade alcohol, 150 Food legislation, 184 Food packaging biodegradable polypropylene, 130e131 cellulose film, 130 Durapulp, 131 high-density polyethylene (HDPE), 130e131 natural biopolymers, 129 poly(lactic) acid (PLA), 130 polysaccharides, 129 synthetic films, 129 vertical form fill seal (VFFS), 130e131 VTT, 132 Food preservation, 45, 115e116, 145 Food safety, 65e66, 139e140, 186, 206, 215e216 Food service packaging, 136e137 Food spoilage, 69 Forestry, 80 Formaldehyde, 65, 68, 81 Fragmentation, 16 Freeze-drying, 40e41 Freeze-thaw, 52 Freezing, 154 Freshness indicators, 155, 157t Frostings, 59 Frozen food, 155 Fungi, 8e9, 34, 57e58 Fungicides, 147

G Galacturonans, 55e56 Gas indicators, 156e157, 157t Gas permeability, 4e5, 68, 203e205, 208 Gel, 40, 48e49, 52, 54, 56e57, 59, 62, 147e149 Gelatin, 60e62 Gelation, 56e57 Gellan, 58e59 Gene delivery, 45 Generally recognized as safe, 186 GHG emissions, 172, 174e175, 177f Glass, 1e2, 7, 29, 75t, 86, 118e123, 125, 132e133, 140e141, 185t, 188te189t, 193 Glaze, 67 Global nano-enabled packaging, 206 Global rigid plastic packaging consumption, 117t Global warming potential (GWP), 175 Gloss, 44e45, 55, 70 Glucans, 57e58

Index

Gluconacetobacter, 38 Glucopyranosyl unit, 54 Glutamine, 61, 71e72 Glutaraldehyde, 60, 65 Gluten, 70e72 Glycerineplasticized zein, 68 Good manufacturing practice (GMP), 184, 187 Grain, 28, 64 Granulation-coated powder, 49 Green algae, 38 Greenhouse gas, 171e172, 174, 174t, 177f Green packaging, 2 Grifola frondosa, 57 Guluronic acid, 46e47 Gum Arabic, 44e45

H Halicystis, 38 Halloysite nanotubes (HNT), 64e65 Haloferax mediterranei, 86 Halomonas boliviensis, 86 Hardness, 44e45, 81 Health care, 31, 117e118, 135, 207 Heteropolysaccharide, 58 Hexafluoroacetone, 39e40 Hexafluoroisopropanol, 39e40 High-density polyethylene (HDPE), 115, 118e122, 130e133, 151, 175, 193, 208 Hog feed, 200 Homogalacturonan, 55e56 Horizon 2020, 213 Humectants, 147e149 Humidity, 4e5, 17e18, 64, 69e70, 115, 130e131, 147e149, 205e206 Hyaluronic acid, 41 Hydraulic oils, 174e175 Hydrocolloid, 28, 45, 49e51, 55, 61, 70e71, 200 Hydrogel, 52, 57 Hydrogen bond, 34, 38e39, 42, 69, 71e72, 206 Hydrolytically, 17 Hydrophilic, 8e9, 16, 32e33, 36, 38, 46e47, 60, 65, 147 Hydrophobic, 28, 39, 66e69, 147, 208 Hydroxyanisole, 151 2-Hydroxypropionic acid, 72e73 Hydroxypropylcellulose, 37 Hydroxytoluene, 65e66, 141e142, 151 Hygroscopic, 42e43, 147e149, 205

I Ice cream, 27e28, 46e47, 49, 52, 62 Icing, 59 Immobilization, 160 Immobilized antibiotics, 147 Immobilized yeast, 148t Immune system, 57 Industrial composting, 7, 172, 195 Infrared scanning technology, 75e76 Injection molding, 114, 205 Injection-stretch blow molding process, 114 Innovation, 125 Inorganic salts, 147e149 Insect, 39 Insulating materials, 151e152 Intelligent packaging systems, 152e161 commercial intelligent packaging systems, 161, 161te163t data carriers, 158e160 barcodes, 158 radiofrequency identification (RFID), 158e160 doneness indicators, 161 indicators, 154e157 freshness indicators, 155, 157t gas indicators, 156e157, 157t temperature indicators, 154e155 sensors, 160e161 thermochromic inks, 161, 161t Interiors, 80 Ion-exchange resins, 185t, 188te189t Ionic gelation method, 40e41 Iota carrageenan, 49 IR emitters, 114e115 Iron powder oxidation, 143e144, 148t Isoelectric point, 71e72

J Jam, 59 Jellies, 46e49, 59

K Kafirin, 19 Kappa carrageenan, 48e49 Kitchenware, 183

225

226

Index

L Lactic drink, 46e47 Lactide formation, 73 Lactobacillus, 52e53 Lambda carrageenan, 49 Laminaria, 38 Laminate, 68e70, 88, 123, 130e131, 137, 146e147, 150, 205e206, 208 Lamination, 37, 118e122 Layered silicates, 4e5, 17e18, 203e205 Lemon extract, 79 Lentinus edodes, 57 Leuconostoc, 52e54 Leuconostoc mesenteroides, 54 Life cycle (LCA) methodology, 172 Lighter plastic packaging, 116 Linear low-density polyethylene, 174 Linear polyesters, 85 1,4-Linked 2-deoxy-2-acetoamido-a-D-glucose, 39 Linoleic acid, 68 Lipids, 18e19, 42, 49, 200 Listeria monocytogenes, 79, 147 Lithium chloride, 39e40 Lithographic printing, 44e45 Loose-fill packaging, 31e32, 135 Low-density polyethylene, 83, 150, 174 Low gas permeability, 208 Lubricants, 171, 173e175, 200 Lysine, 59, 66 Lysozyme, 66, 79, 147

M Macrofibril, 34e35 Maltotriose, 42 Marinades, 59 Marine brown algae, 45 Marketing AsiaePacific region, 195 biodegradable biopolymers, 195 BOPLA, 193 flexible and film packaging sectors, 193 food and beverage packaging, 193 food packaging material, 191 global market share, 192, 192t nonrenewable petrochemical-derived biopolymers, 193 polyamides (PA), 195

polyhydroxyalkanoates (PHAs), 192 polylactic acid (PLA), 193 Mechanical flexibility, 81 Mechanical strength, 19, 33, 60, 76e77 Medical packaging, 88 Medicine, 41, 44e47, 86 Membrane, 37e38, 44e45, 86, 154e155, 160e161, 200 Meniscus repair devices, 89 Metabolix, 88 Metal, 1, 7, 41e42, 44e45, 79, 118e122, 125, 140e142, 144, 147, 160e161, 185t, 188te189t, 193e194 Metal detector, 144 Metallized film, 120t Metal oxides, 160e161 Methane, 174 Methylacetamide, 39e40 Methyl diphenyl diisocynate, 64 MFC, 206e207 Microbial growth, 65e66, 145e147 Microbial spoilage, 65e66, 129, 147e149 Micrococcus lysodeikticus, 79 Microencapsulating agent, 61 Microencapsulation, 5t Microfibril, 33e35 Microorganism, 4e5, 14, 26, 31, 54, 79, 85e88 Microporous, 147e149 Micro porous bags, 147e149 Microstructure, 42 Microwave, 114 Microwave packs, 152 Migration, 17e19, 60, 77, 125, 184, 186 Mildew, 67 Minerals, 4e5, 147e149 Mining, 36, 39 Modified starch, 29, 30t Moisture absorbers, 143t, 147e149 Moisture drip absorber pads, 147e149 Moisture retention, 43e44 Moisturizer, 41 Molding, 205 Molding article, 45 Molecular sieves, 147e149 Monoethylene glycol, 133e134, 195e196 Monomer, 7, 49 Montmorillonite clay, 19 Moths, 67 Mulch film, 82

Index

Multilayer packaging, 3 Multilayer paperboard laminates, 123 Municipal plastic waste, 6 Mushroom, 57 Myriant, 80

N N-acetylated 2-deoxy-2-amino-a-glucan polymers, 39 Nanocellulosic materials, 205 Nanoclay composite coating, 208 Nanocomposites, 4e5, 203e205 Nanoelectronics, 204t Nanofibers, 207 Nanometer scale, 4e5 Nanoparticles, 66, 203e205, 214 Nanophobia, 216 Nanoplates, 208 Nanoreinforcement, 214 Nanosensors, 209 Nanotechnology cellulose nanomaterials, 208 clay particles, 203e205 definition, 203 diverse applications, 204t food packaging, 206 future prospects, 215e216 global nano-enabled packaging, 206 low gas permeability, 208 MFC, 206e207 nanocellulosic materials, 205 nanocomposites, 203e205 nanosensors, 209 packaging industry, 205e206 TEMPO-oxidized cellulose nanofibers, 207 vermiculite nanoplatelets, 208 Native cotton, 34 Native starch, 29 Natural biopolymer films, 5t Natural biopolymers, 26 Natural gas, 171e172 Natural PHAs, 86 Nisin, 65e66, 79, 147 Noncarbonated beverages, 132 Noncarcinogenic, 43e44 Nonfood packaging, 134e136 Nongelatin capsule, 49 Nonimmunogenic, 43e44 Nonionic, 43e44

Nonmutagenic, 43e44 Nonpolar amino acids, 67 Nonrenewable resources, 171e172 Nontoxic, 43e44 Nontoxicity, 39 Nonwoven fabrics, 44e45 Non-woven plastic film, 147e149 Nonwoven polymer, 144e145 Novamont, 31 NOVON polymers, 31 Nuclear magnetic resonance (NMR), 33e34 Nucleic acids, 26, 200 Nutraceuticals, 56e57, 67 Nutritional supplement, 5, 201 Nutrition products, 200 Nylon fiber, 44e45

O Odor absorber, 50e52 Oil and gas recovery, 36 Oleic acid, 68 Oligomers, 185e186 Oligosaccharide, 55 Omega-3 fatty acids, 200 Omega-6 fatty acids, 200 Open pond systems, 201 Ophthalmology, 60 Optical film, 37 Optical oxygen sensors, 160e161 Optochemical sensors, 160e161 Oral care product, 45 Organic acids, 65e66, 79 Organic sulfates, 151 Organoleptic characteristic, 5t Organoleptic properties, 77 Organophilic, 203e205 Organophosphate compounds, 141e142 Oxidatively degradable, 17 Oxo-degradable polyolefins, 17 Oxygen barrier, 4e5, 19, 42e44, 205, 208 Oxygen blockers, 69 Oxygen permeability, 17e18, 205, 207 Oxygen scavengers, 142e145, 143t Oxygen transmission rate (OTR), 206e207

P Packaging beverage, 132e134 films, 57, 60, 69, 117e127, 144e145

227

228

Index

Packaging (Continued) flexible, 117e127, 119t, 120f, 120t, 124t, 126t food, 129e132 food service, 136e137 industry, 1e2, 80, 117e118, 195, 205e206 nonfood, 134e136 rigid, 113e117, 113t, 114f Packet soup, 52 Paddle wheel, 201 Paints, 44e45 Paper and board, 6 Paper-based packaging, 117e118 Paperboard, 2 Paper-coating formulations, 19 Paper industry, 33 Pathogenic microorganisms, 79 PBS, 81e82 Pectin, 55e57 Pectin methylesterase, 56e57 Pedi coccus, 52e53 Pencil graphite, 160 Pentasaccharide, 50e51 Peptides, 147 Personal care, 38, 126 Personal care industry, 41 Pesticides, 209 Petrochemical polymers, 194 Petrochemicals, 7e8, 82, 86 Petroleum-based plastics, 1, 69e70, 171 Petroleum-based products, 1 Petroplastics, 175 PHA. See Polyhydroxyalkanoate (PHA) Pharmaceutical, 41e42, 45, 47, 67 Pharmaceutical capsule, 31 Pharmaceutical industry, 38, 45e47, 54, 59 Pharmacology, 86 Pharma industry, 38 Phellinus baummi, 57 Photobiodegradable, 17 Photobioreactors, 198e199, 201 Photocatalytic activity, 66 Photography, 62 Photosensitive dye oxidation, 148t Photosynthesis, 26e27, 198 Physical adsorption, 149 Piezoelectric crystal sensors, 160e161 Pigments, 123, 198 Pig skin, 59, 61e62 Plant breeding methods, 29

Plant extract, 79 Plant growth stimulator, 52 Plasma cholesterol, 57 Plastic(s), 1e2, 7e9, 16e17, 29, 31, 35, 68e69, 82, 113, 193, 195 Plasticized, 29, 36e37, 68 Plasticized starch, 29 Plastic packaging, 114, 118, 120t Plastic sachets, 144 Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), 85e86 Poly(3-hydroxybutyrate-co-4-hydroxybutyrate), 85e86 Poly(3-hydroxyhexanoate-co-3hydroxyoctanoate), 85e86 Poly(L-lactide), 73 Poly(pphenylene), 26t Poly(trimethylene terephthalate), 26t Poly(vinyl alcohol) (PVOH), 134 Poly(lactic) acid (PLA), 130 Polyacrylate salts, 147e149 Polyamides (PA), 13 Polyamines, 147 Polybutylene succinate, 79e82 Polycaprolactone, 41e42 Polycarbodiimide, 77 Polycarbonate, 149 Polycondensation, 73 Polyester, 8e9, 79 Polyethylene (PE), 82, 114 Polyethylene furandicarboxylate (PEF), 175 Polyethylene glycol, 86 Polyethylenes, 26, 31, 36 Polyethylene terephthalate (PET), 114, 132e133 Polyhydroxyalkanoate (PHA), 13, 84e89, 175, 214 Polyhydroxybutyrate (PHB), 14 Polylactic acid (PLA), 13, 72e79 Polymerization, 34 Polymer multilayers, 120t Polymers from biobased monomers biopolyethylene, 82e84 polybutylene succinate, 79e82 polyhydroxyalkanoates, 84e89 polylactic acid, 72e79 Polyolefin, 17, 29, 81 Polyoxy salt, 40 Polypeptides, 59 Polypropylene (PP), 114

Index

Polypropylenes, 149 Polysaccharides, 4e5, 8, 129 Polystyrene (PS), 114 Polystyrenes, 79 Polytetramethylene succinate, 79 Polythene, 7 Poly-vinyl alcohol, 64e65 Polyvinyl chloride (PVC), 114 Pork, 59 Potassium permanganate, 149 Potato, 26 Pouch, 119t, 193 Powdered iron, 144 Prebiotic oligosaccharides, 55 Prebiotics, 55, 65 Precycling benefits, 124e125 Prehydrolysis kraft pulping, 35 Pretreatment, 59, 61, 206 Printed electronics, 3 Printing inks, 185t, 188te189t Probiotics, 65 Processed food, 193, 209, 215 Prolamines, 66e67 Prometastatic protein, 57 1,2,3-Propanetrioldiglycidyl-ether, 64e65 Protective barrier, 49 Protein denaturation, 154 Protein films, 4e5 Pseudomonas, 45, 85e86 Pseudomonas elodea, 58 Pseudomonas putida, 85e86 Puddings, 49, 62 Pullulan, 42e45 Pulmonary inflammation, 215e216 Puncture strength, 71 Pure cellulose, 35e36 Pyruvic acid, 50e51

Q Quantum dots, 43e44

R Raceway ponds, 201 Ralstonia eutropha, 86 Regenerated cellulose, 184, 188te189t Renewable substrates, 1, 214 RenewFuncBarr project, 3 Repair patches, 89 Respiration, 145, 147e149

Retrogradation, 28 Rhamnogalacturonans, 55e56 Rhamnopyranosyl residue, 55e56 Rhamnose, 58 Rheological behavior, 48e49 Rhynchelytrum repens, 57 Rice, 27e28 Rigid containers, 123, 124t, 193 Rigid corrugated box, 117e118 Rigidity, 81 Rigid packaging, 113e117, 113t, 114f Asia, 117 biodegradable packaging, 116 expanded polystyrene (EPS), 114 global rigid plastic packaging consumption, 117t high-density polyethylene (HDPE), 115 key players, 117t lighter plastic packaging, 116 materials, 113 plastic packaging, 114 polyethylene (PE), 114 polyethylene terephthalate (PET), 114 polypropylene (PP), 114 polystyrene (PS), 114 polyvinyl chloride (PVC), 114 sustainable packaging, 116 technology, 116 thermoplastic (TPS) starchbased plantic range, 114 Ring opening polymerization, 73e74 Rivets, 89 Road deicers, 31 Rubber latex, 209 Rubbers, 185t, 187, 188te189t

S Saccharomyces cerevisiae, 58 Sachets, 143e144, 150 Salad dressing, 124 Salads, 46e47 Sarcina, 38 Saturated fatty acid oxidation, 148t Sausage-casing, 49 Scaffold, 52 Scavengers, 3, 141e145, 149 Seaweed, 46e48, 197e199 Seaweed farming, 47 Sebacic acid, 81 Security-enabled packaging, 126e127

229

230

Index

Selfhealing coatings, 3 Sensors, 160e161 biosensor, 160 gas sensors, 160e161 Sephadex, 55 Shelf life, 4e5, 7e8, 49, 69, 129 Shellfish, 39, 41 Shopping bags, 17 Silica gel, 147e149 Silicon dioxide powder, 150 Silicones, 185t, 188te189t Silicon polycarbonates, 149 Silver, 55, 79, 146e147, 160 Silver ions, 146e147 Silver zeolite, 37, 79 Small-scale pilot plants, 177 Smart packaging, 209 Sodium sulfate, 35, 151 Soft capsules, 49 Soft cheese, 130 Softwood-dissolving pulp, 206 Soil conditioner, 31 Soluble fiber, 57 Sorghum, 19, 27 Sorption, 132e133, 205 Sources, biopolymers algae, 197e198, 200e201 Biotechnology Institute, 199 high-value microalgal products, 200 international algae market, 199 photosynthetic pigments, 198 renewable biopolymers packaging sector, 198 Soybeans, 63 Soy flour, 63 Soy protein, 63e65 Soy protein concentrate, 63 Soy protein isolate (SPI), 18e19, 63e64 Spirulina, 199e200 Stabilizer, 31, 45e47, 49, 51, 59 Staphylococcus aureus, 79 Starch, 8e9, 26e33 Starch-based materials, 29 Starch-based polymers, 32e33 Starch-based products, 32t Starch copolymers, 147e149 Starch plastic, 29, 31 Starch-zein composites, 68 Storage life, 42 Streptococcus, 52e53

Styrene-acrylic latexe, 19 Styrene-acrylonitrile, 123 Substantial attention, 1 Succinic acid, 79, 81 Sugar beet, 56e57, 206 Sugarcane, 17, 54, 83e84, 175 Sugarcane ethanol, 83e84 Sulfated galactan, 49 Sunflower head, 55e56 SUNPAP project, 3 Superabsorbent polymer, 144e145, 147e149 Surface acetylation, 207 Surface area, 38e39 Surface sizing, 33 Surfactant, 19 Surgery, 86 Surgical mesh, 89 Susceptors, 152 Sustainable development, 2 Sustainable packaging sector, 2 Sustainable raw materials, 26 SustainPack, 3 Suture fasteners, 89 Sutures, 55, 89 Synthetic additives, 141e142 Synthetic film, 7e8, 129 Synthetic films, 129 Synthetic PHAs, 86

T Tableware, 76 Tapioca, 198 Temperature-controlled packaging, 151e152 Temperature indicators, 154e155 TEMPO-oxidized cellulose nanofibers, 207 Tensile strength, 35, 44e47, 64, 68 Tetrasaccharide, 58 Textile fiber, 35 Textiles, 32, 35e37, 77, 185t, 188te189t Texturing agent, 57 Theft prevention, 158 Thermal denaturation, 60 Thermally stable, 43e44 Thermal stability, 17e18 Thermochromic inks, 161, 161t Thermoplastic polymer resin, 79 Thermoplastic starch (TPS), 29, 114, 175 Thermoset plastic, 68e69 Thermosetting resins, 209

Index

Thickener, 31, 37, 46e47, 52, 56e57, 205e206 Thioester, 141e142 Thymol, 79 Time temperature integrators, 154e155, 155t Tissue engineering, 43e47 Tissue morphogenesis, 60 Tissue repair, 60 Tissue repair patches, 89 Tissue scaffolding, 60 Titanium dioxide, 66 Tobacco industry, 37t Tocopherols, 151 Toppings, 59 Toxicological properties, 51 Traceability, 129e130, 159e160 Transesterification, 81 Transgenic microorganisms, 86 Translucent sheet, 70e71 Trays, 76, 88, 114, 191e192 Tremella aurantia, 57 Tremella mesenterica, 57 Tryptophan, 66 Tuber, 27 Tubular photobioreactors, 201 Twin screw extruder, 70e71 Twist wraps, 120t

U Ultrasonication, 19 Unicellular, 197e198 US Food and Drug Administration, 43e44, 215e216

V Valonia, 38 Van der waals force, 34 Vapor transmission rate, 71, 201e202 Varnishes and coatings, 185t, 188te189t Vascular disease, 13 Vermiculite nanoplatelets, 208 Vertical form fill seal (VFFS), 130e131 Veterinary medicine, 204t Viscoelastic dough, 70 Viscosifier, 45 Viscosity, 28, 44e47 Vitamins, 65

Voronezh State Forest Technical Academy, Russia, 206

W Waste disposal, 1, 6, 16, 191 Waste management, 18, 86, 134e135 Water absorption, 64e65, 151e152 Water coating, 37t Water solubility, 43, 63, 118e122 Water treatment, 46e47, 204t Water vapor barrier, 2, 4e5, 19, 65, 207, 215 Water vapor permeability, 19, 42, 63e64, 66, 68 Water vapor transmission rate, 71, 205e206 Waxes, 88, 185t, 188te189t Waxing, 67 Waxy corn, 29 Weapons, 204t Weissella, 52e53 Wheat, 8t, 27e28, 70e73, 83e84, 133e134, 149, 175, 198 Wheat gluten, 70e71 Whey protein, 65e66 Whey protein isolates (WPIs), 65e66 Whipped cream, 48e49 Whitening additive, 118e122 Wide-angle x-ray scattering, 34e35 Wood, 33e36, 38e39, 63, 80, 83e84, 118e122, 132e134, 171, 185t, 188te189t, 207, 213 Wood plastic composites, 80 Wound healing, 43e47 Writing and printing paper, 44e45

X Xanthan, 50e52 Xanthine, 160 Xanthine oxide, 160 Xanthomonas campestris, 51 X-ray crystallography, 27e28, 33e34 Xylan, 19 Xylogalacturonans, 55e56

Y Yeast, 8e9, 39, 42e43, 57e58, 143t, 148t, 149

Z Zea may, 57, 66 Zein, 66e68

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