Milk-based beverages 9780128155042, 0128155043, 9780128157114

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MILK-BASED BEVERAGES

MILK-BASED BEVERAGES Volume 9: The Science of Beverages Edited by

ALEXANDRU MIHAI GRUMEZESCU ALINA MARIA HOLBAN

An imprint of Elsevier

Woodhead Publishing is an imprint of Elsevier The Officers’ Mess Business Centre, Royston Road, Duxford, CB22 4QH, United Kingdom 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, OX5 1GB, United Kingdom © 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: 978-0-12-815504-2 (print) ISBN: 978-0-12-815711-4 (online) For information on all Woodhead publications visit our website at https://www.elsevier.com/books-and-journals

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CONTRIBUTORS Ceren Akal  Faculty of Agriculture, Department of Dairy Technology, Ankara University, Ankara, Turkey Buket Aydeniz Guneser  Department of Food Engineering, Usak University, Usak, Turkey B.V. Balasubramanyam  ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru, India Sheweta Barak  Department of Dairy & Food Technology, Mansinhbhai Institute of Dairy & Food Technology, Mehsana, India Carina Viviana Bergamini  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina Preeti Birwal  Dairy Engineering, SRS of ICAR-NDRI, Bengaluru, India Damiano Cortese  Department of Management, University of Turin, Torino, Italy Adriano Gomes da Cruz  Food Department, Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ), Rio de Janeiro, Brazil Thayse Caroline de Abreu Brandi  Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Lucianne Cople Maia  Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Gajanan P. Deshmukh  Dairy Engineering, SRS of ICAR-NDRI, Bengaluru, India F. Magdaline Eljeeva Emerald  ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru, India Andréa Fonseca-Gonçalves  Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Onur Guneser  Department of Food Engineering, Usak University, Usak, Turkey Erica Hynes  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina

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Muge Isleten Hosoglu  Department of Food Engineering, Canakkale Onsekiz Mart University, Canakkale, Turkey Yonca Karagul Yuceer  Department of Food Engineering, Canakkale Onsekiz Mart University, Canakkale, Turkey Yogesh Khetra  Dairy Technology Division, National Dairy Research Institute, Karnal, India I. Loira  Polytechnic University of Madrid, Madrid, Spain Giampiero Lombardi  Department Agricultural, Forest and Food Sciences, University of Turin, Torino, Italy Marcela Baraúna Magno  Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Ali Mohamadi Sani  Quchan Branch, Islamic Azad University, Quchan, Iran A. Morata  Polytechnic University of Madrid, Madrid, Spain Deepak Mudgil  Department of Dairy & Food Technology, Mansinhbhai Institute of Dairy & Food Technology, Mehsana, India Patricia Nadelman  Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Nalan Hakime Noğay  Faculty of Health Science, Department of Nutrition and Dietetics, Erciyes University, Kayseri, Turkey Javier Ochando-Pulido  Department of Chemical Engineering, University of Granada, Granada, Spain Barbaros Özer  Faculty of Agriculture, Department of Dairy Technology, Ankara University, Ankara, Turkey F. Palomero  Polytechnic University of Madrid, Madrid, Spain Saurabh S. Patel  ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru, India Giovanni Peira  Department of Management, University of Turin, Torino, Italy María Cristina Perotti  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina Sandra Pimentel-Moral  Department of Analytical Chemistry, Faculty of Sciences, University of Granada; Research and Development Functional Food Centre (CIDAF), Health Science Technological Park, Granada, Spain Matheus Melo Pithon  Department of Health, School of Dentistry, Universidade Estadual do Sudoeste da Bahia (UESB), Bahia, Brazil

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Heartwin A. Pushpadass  ICAR-National Dairy Research Institute, Southern Regional Station, Bengaluru, India Mohammad Rahbar  Quchan Branch, Islamic Azad University, Quchan, Iran Menon Rekha Ravindra  Dairy Engineering, SRS of ICAR-NDRI, Bengaluru, India Bhargavi Rayavarapu  Department of Microbiology, School of Sciences, Jain University, Bangalore, India Celia Rodríguez-Pérez  UCD School of Agriculture and Food Science, Institute of Food and Health, University College Dublin (UCD), Dublin 4, Ireland Latha Sabikhi  Dairy Technology Division, National Dairy Research Institute, Karnal, India Mahya Sheikhzadeh  Quchan Branch, Islamic Azad University, Quchan, Iran J.A. Suarez-Lepe  Polytechnic University of Madrid, Madrid, Spain Padmavathi Tallapragada  Department of Microbiology, School of Sciences, Jain University, Bangalore, India W. Tesfaye  Polytechnic University of Madrid, Madrid, Spain Nazli Turkmen  Faculty of Agriculture, Department of Dairy Technology, Ankara University, Ankara, Turkey María Ayelén Vélez  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina Jorge Fernando Vélez-Ruiz  Department of Chemical and Food Engineering, Universidad de las Américas Puebla; Food Network Consulting, S.A. de C. V. Instituto de Innovación y Desarrollo Tecnológico, Puebla, México Claudia Inés Vénica  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina Irma Verónica Wolf  Institute of Dairy Science and Industry (INLAIN), National University of Litoral/National Council of Science and Technology (UNL/CONICET), Faculty of Chemical Engineering (FIQ), Santa Fe, Argentina

SERIES PREFACE Food and beverage industry accounts among the most developed sectors, being constantly changing. Even though a basic beverage industry could be found in every area of the globe, particular aspects in beverage production, processing, and consumption are identified in some geographic zones. An impressive progress has recently been observed in both traditional and modern beverage industries and these advances are leading beverages to a new era. Along with the cutting-edge technologies, developed to bring innovation and improve beverage industry, some other human-related changes also have a great impact on the development of such products. Emerging diseases with a high prevalence in the present, as well as a completely different lifestyle of the population in recent years have led to particular needs and preferences in terms of food and beverages. Advances in the production and processing of beverages have allowed for the development of personalized products to serve for a better health of overall population or for a particular class of individuals. Also, recent advances in the management of beverages offer the possibility to decrease any side effects associated with such an important industry, such as decreased pollution rates and improved recycling of all materials involved in beverage design and processing, while providing better quality products. Beverages engineering has emerged in such way that we are now able to obtain specifically designed content beverages, such as nutritive products for children, decreased sugar content juices, energy drinks, and beverages with additionally added health-promoting factors. However, with the immense development of beverage processing technologies and because of their wide versatility, numerous products with questionable quality and unknown health impact have been also produced. Such products, despite their damaging health effect, gained a great success in particular population groups (i.e., children) because of some attractive properties, such as taste, smell, and color. Nonetheless, engineering offered the possibility to obtain not only the innovative beverages but also packaging materials and contamination sensors useful in food and beverages quality and security sectors. Smart materials able to detect contamination or temperature differences which could impact food quality and even pose a hazardous situation for the consumer were recently developed and some are already utilized in packaging and food preservation.

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This 20-volume series has emerged from the need to reveal the current situation in beverage industry and to highlight the progress of the last years, bringing together most recent technological innovations while discussing present and future trends. The series aims to increase awareness of the great variety of new tools developed for traditional and modern beverage products and also to discuss their potential health effects. All volumes are clearly illustrated and contain chapters contributed by highly reputed authors, working in the field of beverage science, engineering, or biotechnology. Manuscripts are designed to provide necessary basic information in order to understand specific processes and novel technologies presented within the thematic volumes. Volume 1, entitled Production and management of beverages, offers a recent perspective regarding the production of main types of alcoholic and nonalcoholic beverages. Current management approaches in traditional and industrial beverages are also dissected within this volume. In Volume 2, Processing and sustainability of beverages, novel information regarding the processing technologies and perspectives for a sustainable beverage industry are given. Third volume, entitled Engineering tools in beverage industry dissects the newest advances made in beverage engineering, highlighting cutting-edge tools and recently developed processes to obtain modern and improved beverages. Volume 4 presents updated information regarding Bottled and packaged waters. In this volume are discussed some wide interest problems, such as drinking water processing and security, contaminants, pollution and quality control of bottled waters, and advances made to obtain innovative water packaging. Volume 5, Fermented beverages, deals with the description of traditional and recent technologies utilized in the industry of fermented beverages, highlighting the high impact of such products on consumer health. Because of their great beneficial effects, fermented products still represent an important industrial and research domain. Volume 6 discusses recent progress in the industry of Nonalcoholic beverages. Teas and functional nonalcoholic beverages, as well as their impact on current beverage industry and traditional medicine are discussed. In Volume 7, entitled Alcoholic beverages, recent tools and technologies in the manufacturing of alcoholic drinks are presented. Updated information is given about traditional and industrial spirits production and examples of current technologies in wine and beer industry are dissected. Volume 8 deals with recent progress made in the field of Caffeinated and cocoa-based beverages. This volume presents the great variety of

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such popular products and offers new information regarding recent technologies, safety, and quality aspects as well as their impact on health. Also, recent data regarding the molecular technologies and genetic aspects in coffee useful for the development of high-quality raw materials could be found here. In Volume 9, entitled Milk-based beverages, current status, developments, and consumers trends in milk-related products are discussed. Milk-based products represent an important industry and tools are constantly been developed to fit the versatile preferences of consumers and also nutritional and medical needs. Volume 10, Sports and energy drinks, deals with the recent advances and health impact of sports and energy beverages, which became a flourishing industry in the recent years. In Volume 11, main novelties in the field of Functional and medicinal beverages, as well as perspective of their use for future personalized medicine are given. Volume 12 gives an updated overview regarding Nutrients in beverages. Types, production, intake, and health impact of nutrients in various beverage formulations are dissected through this volume. In Volume 13, advances in the field of Natural beverages are provided, along with their great variety, impact on consumer health, and current and future beverage industry developments. Volume 14, Value-added Ingredients and enrichments of beverages, talks about a relatively recently developed field which is currently widely investigated, namely the food and beverage enrichments. Novel technologies of extraction and production of enrichments, their variety, as well as their impact on product quality and consumers effects are dissected here. Volume 15, Preservatives and preservation approaches in beverages, offers a wide perspective regarding conventional and innovative preservation methods in beverages, as well as main preservatives developed in recent years. In Volume 16, Trends in beverage packaging, the most recent advances in the design of beverage packaging and novel materials designed to promote the content quality and freshness are presented. Volume 17 is entitled Quality control in beverage industry. In this volume are discussed the newest tools and approaches in quality monitoring and product development in order to obtain advanced beverages. Volume 18, Safety issues in beverage production, presents general aspects in safety control of beverages. Here, the readers can find not only the updated information regarding contaminants and risk factors in beverage production, but also novel tools for accurate detection and control.

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Volume 19, Biotechnological progress and beverage consumption, reveals novel tools used for advanced biotechnology in beverage industry production. Finally, Volume 20 entitled Nanoengineering in beverage industry take the readers into the nanotechnology world, while highlighting important progress made in the field of nanosized materials science aiming to obtain tools for a future beverage industry. This 20-volume series is intended especially for researchers in the field of food and beverages, and also biotechnologists, industrial representatives interested in innovation, academic staff and students in food science, engineering, biology, and chemistry-related fields, pharmacology and medicine, and is a useful and updated resource for any reader interested to find the basics and recent innovations in the most investigated fields in beverage engineering.

Alexandru Mihai Grumezescu Alina Maria Holban

PREFACE Volume 9 of The Science of Beverages series presents recent advances made in the field of dairy industry. Classical milk beverages are consumed in every area of the globe, being a rich source of nutrients and health-promoting components. With the great changes in the modern society, distinct preferences and needs emerged in terms of dairy products. To meet the various consumer demand impressive innovative tools and technological progress have emerged in the production and processing of milk-based products. Although traditional products are still preferred by the general population, news tools and approaches are currently used to obtain a greater amount of a particular product or improved beverages, while keeping the properties of products that are manufactured by classical methods. This volume brings together the most interesting news in the field of milk-based drinks, while providing necessary basic information to understand current needs and future perspectives in this area. The volume contains 15 chapters prepared by outstanding authors from Turkey, India, Ireland, Argentina, Iran, Italy, Mexico, Spain, and Brazil. The selected manuscripts are clearly illustrated and contain accessible information for a wide audience, especially food and beverage scientists, engineers, biotechnologists, biochemists, industrial companies, students and also any reader interested in learning about the most interesting and recent advances in beverage science. Chapter  1, Engineering of milk-based beverages: current status, ­developments, and consumer trends, by Onur Guneser et al., focuses on the production technologies and applications of milk-based beverages and discusses the physicochemical properties and health benefits of some milk-based beverages such as whey beverages, fermented milk products (probiotic dairy beverages, kefir, buttermilk, koumiss), and dairy beverages fortified with bioactive compounds. Also, recent developments and hot consumer trends in milk-based beverages ­market are discussed in detail. Chapter  2, Engineering milk-based beverages, by Yogesh Khetra et  al., describes the most important approaches developed for milk product stabilization and to increase quality and bioavailability of functional ingredients. Also, aspects regarding structural modification tools and engineering of milk beverages are presented, together with updated examples. Chapter  3, Dairy-based functional beverages, by Deepak Mudgil et al., discusses the main reasons supporting the worldwide market for

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functional foods as a potent and growing segment of the food industry. Functional dairy beverages can be divided into two major segments: fortified dairy beverages such as probiotic and prebiotics, fiber fortified, and minerals and vitamins fortified dairy beverages and whey-based beverages. Dairy-based probiotic beverages can prevent diseases associated with human digestive system via its beneficial effect on gut microbiota of humans. Bioactive or functional components such as omega-3 fatty acids, phytosterols, isoflavones, conjugated linoleic acid, and dietary fibers are associated with reduced risk of cardiovascular diseases and certain types of cancer. Fortification or addition of these bioactive components in dairy-based beverages makes them functional beverages as they have some health benefits. Mineral and vitamin fortification of dairy-based beverages has also been carried out to compensate the loss of minerals and vitamins occurring during processing. Whey, a by-product of cheese industry, has also been utilized for the development of whey-based functional beverages. Functionality of whey is due to the addition of lactoferrin, immunoglobulins, and growth factors. Chapter  4, New trends in functional dairy-based beverages, by Celia Rodríguez-Pérez et al., encompasses recent scientific and technological development, mainly focused on mechanisms involved in the formulation, bioactivity evaluation, and current legal framework of functional dairy-based beverages. It seems that to satisfactorily develop functional dairy-based beverages, nanotechnology is emerging as an effective way to incorporate nano-encapsulated bioactive compounds and/or release them to target sites in the body, hence, facilitating their biological activity. Chapter 5, Recent trends and developments in milk-based beverages, by Padmavathi Tallapragada et al., dissects the newest approaches employed in order to develop additional potential uses of milk beverages. There has been growing interest in potential use of milk as an alternative sports drink to optimize the hydration levels in athletes due to the natural presence of water and electrolytes like sodium and potassium. Chapter  6, Functional milk-based beverages, by María Cristina Perotti et al., reports the current knowledge on the technological approaches applied to obtain functional milk-based beverages, with special emphasis on the more recent technologies and focus on the quality and functional properties of the products. Original results of the authors are also included in this work. Chapter 7, Traditional beverages in different countries: milk-based beverages, by Ali Mohamadi Sani et al., presents some advances made in the dairy industry, one of the most advanced food sectors ­regarding the application of novel technologies to process milk-based products which are important for human health. Due to the increasing consumption of milk-based products, different types of fermented milk such as yogurt, kefir, koumiss, chal, kurut, airag, whey beverages,

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ymer, cuajada, shubat, labneh, suusac, kulenaoto, obtained from buffalo, goat, sheep, camel, yak, or mare milk, are manufactured throughout the world. The majority of these traditional products are produced in The Middle East, Southeast Asia, West Asia, Central Asia, Eastern Europe, South America, and Mediterranean countries. Progress made to improve the quality and safety of milk-based traditional products, as well as proposed alternative products have been reported here. Chapter 8, Kefir beverage and its effects on health, by Nalan Hakime Noğay et al., aims to explain the main beneficial effects of kefir on human health. Kefir is a fermented milk product having a slight acidic taste, natural carbonation, and aroma. Traditionally kefir is produced by milk inoculation with kefir grains, which have particular color, ranging from white to yellow, comprising an inert matrix (polysaccharides and proteins) inhabited by a large population of lactic acid bacteria, acetic acid bacteria, and yeasts. Kefir has raised interest due to its numerous beneficial effects on health. The health benefits associated with kefir are gastrointestinal proliferation, antibacterial, anticarcinogenic effect, hypocholesterolemic effect, antidiabetic properties, antimutagenic activity, β-­galactosidase activity, effect on lipid and blood pressure level, protection against apoptosis, antiallergic properties, anti-inflammatory action, bacterial colonization, immunomodulating capacity, and healing effects. Authors conclude there is a need for systematic clinical trials to better understand the effects of regular use of kefir in preventing diseases. Chapter 9, The supply chains of cow grass-fed milk, by Giampiero Lombardi et  al., defines what grass-fed milk is. It then goes on to analyze some representative grass-fed milk production systems in Northern Italy and a successful case study in Europe. Lastly, after a discussion on systems’ sustainability, this chapter reports some consumer surveys on inclination to consume grass-fed milk and on consumers’ willingness to pay for them. Chapter  10, Technology of dairy-based beverages, by Ceren Akal et  al., deals with the recent scientific, technological, and commercial developments in the dairy-/whey-based beverage sector as well as models for interdisciplinary approaches for justification of health claims and biocompatibility of such products. Chapter  11, Rheological properties of milk-based beverages, by Heartwin A. Pushpadass et al., aims to review the various flow behavior models for milk beverages, which could yield dynamic viscosity or consistency coefficient. The later part discusses the rheological properties of plain milk and acidified milk beverages such as yogurt types, lassi, doogh and whey-based beverages. Also, the microstructure and major factors influencing the rheological properties of these beverages are elaborated. Chapter  12, Nonthermal processing of dairy beverages, by Preeti Birwal et al., discusses the basics of and systems employed for some

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emerging nonthermal techniques with reference to its application in dairy beverages including, milk and milk-based beverages, fermented dairy drinks, whey, and colostrum. The effect of the aforementioned treatments on the quality and safety (sensory attributes, physicochemical effects, and microbial effects) of the above products will also be reviewed in the chapter. Chapter  13, Rheological characterization and pipeline transport needs of two fluids dairy products (flavored milk and yogurt), by Jorge Fernando Vélez-Ruiz et al., illustrates the food engineering, food science and investigation development on food process operations, particularly the liquid dairy products. Basic and practical aspects related to the flow characterization of some dairy products and pipe transportation are introduced in this study, including some data, rheograms, experimental results, as well as tables and figures for dairy fluid product properties and those parameters that are involved in pipeline transport. Chapter  14, Dairy and nondairy-based beverages as a vehicle for probiotics, prebiotics, and symbiotics: alternatives to health vs. disease binomial approach through food, by Tesfaye W. et al., discusses strategies proposed to tackle new challenges through the development of effective, cheap, and accessible remedies such as probiotic and symbiotic foods. These approaches are mainly targeted on promoting selectively the growth and/or activity of one or a limited number of beneficial bacteria in the colon. Biological roles of functional beverages components relied on the metabolites generated by the interaction between phytochemicals and gut microbiota via esterase, glucosidase, demethylation, dihydroxylation, and decarboxylation activities thus exerting their noteworthy healthy effect through different mechanisms. Symbiotic functional beverages include those with combined probiotic and prebiotic food matrices that can act synergistically to modulate the intestinal microbiota positively. Chapter 15, The effect of dairy probiotic beverages on oral health, by Marcela Baraúna Magno et  al., presents the benefits attributed to the consumption of functional beverages containing probiotic microorganisms, in which the most popular are produced by the dairy industry. Considering the promising results observed with the use of dairy products, this chapter aims to present and discuss an updated viewpoint of the effects of probiotic dairy drinks on oral health, describing the relationship between the consumption of these functional beverages and the main oral diseases, oral microbiota, and salivary immune components.

Alexandru Mihai Grumezescu

University Politehnica of Bucharest, Bucharest, Romania

Alina Maria Holban

Faculty of Biology, University of Bucharest, Bucharest, Romania

ENGINEERING OF MILK-BASED BEVERAGES: CURRENT STATUS, DEVELOPMENTS, AND CONSUMER TRENDS

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Onur Guneser⁎, Muge Isleten Hosoglu†, Buket Aydeniz Guneser⁎, Yonca Karagul Yuceer† *

Department of Food Engineering, Usak University, Usak, Turkey †Department of Food Engineering, Canakkale Onsekiz Mart University, Canakkale, Turkey

1.1 Introduction Consumers are becoming more aware of what they are eating and have been changing their eating habits due to the increasing interest for maintaining and improving their health and wellness. Healthier foods having physiological effects on body apart from providing basic nutrition are recognized as “functional foods” (Argan et al., 2015). Beverages are recognized as the most active functional foods category. It was emphasized that functional beverage sales reached over $22 ­billion and about 59% of the total functional food market comprises functional beverages in the United States (Sloan and Hutt, 2012). Outside of the United States, Germany, France, the United Kingdom, and the Netherlands are the most important countries within the functional food market in Europe. Among the European countries, there is only a sizeable functional beverage market in Germany. It has $301 million accounting for pro-, pre-biotic, and other functional yogurts and $118 million for functional beverages in 2000. Hence, the functional beverage market in 2015 was worth approximately $7 billion in Japan which is regarded as the birthplace of functional foods. For example, retail sales of functional milk in Japan were $695.9 million in 2015 (Anonymous, 2016; Hilliam, 2000). The trends of functional beverages differ from country to country and are growing at different rates with regard to consumer perceptions Milk-based Beverages. https://doi.org/10.1016/B978-0-12-815504-2.00001-3 © 2019 Elsevier Inc. All rights reserved.

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and choices. Therefore, beverages seem to be an opportunistic way to meet new consumer demands for container contents, size, shape, and appearance and they have many possibilities to incorporate desirable nutrients and bioactive compounds (Corbo et al., 2014; Sorenson and Bogue, 2009; Sloan and Hutt, 2012). From this point of view, milkbased beverages are the most acceptable foods for consumers in the functional food market (Özer and Kirmaci, 2010; Argan et al., 2015). Milk is a vital part of the healthy human diet from birth. Milk and dairy products have wide varieties of essential nutrients for growth and maintenance of the human body. For instance, casein, whey proteins and immunoglobulins, conjugated linoleic acid (CLA), lactose and minor oligosaccharides such as prebiotics, calcium, phosphorous, vitamin D, and riboflavin, various probiotics bacteria such as Bifidobacterium bifidum are present in milk and dairy products as main nutrients for promoting the health and for the maintenance of the human body. Approximately, 43% of the functional foods market consists of milk-based foods (Özer and Kirmaci, 2010; Mellema and Bot, 2009; Kelly et al., 2009). Milk-based beverages have been substantially dominated the functional food market over the last decades and milk-based beverages containing various bioactive ingredients have an outstanding position in this dominance of the market. Therefore, several food technologists in the industry and researchers are making efforts to introduce new milk-based beverage formulations to consumers. When the shelves of grocery stores are examined, a wide range of beverages made from milk and/or isolated ingredients from milk, fruits, and cereals (Kanekanian, 2014; Özer and Kirmaci, 2010) were found. Basically, milk-based beverages can be categorized into two main groups: (i) unfermented milk and milk derivatives and (ii) fermented milk products. Both groups of milk beverages have varied physical, chemical, microbiological, and sensory properties as well as different production technologies. First groups of milk beverages includes flavored milk, fortified milks with bioactive compounds (sterols, fish oils, fibers, etc.), vitamins and minerals, and a mixture of milk/whey and fruit juice while Kefir, Koumiss, Yakult, Buttermilk, and fermented milk with probiotics are the some members of the second group (Jelen, 2009). The production of the first group of milk beverages comprises modern food processing techniques such as high shear mixing, encapsulation, and well-developed emulsification while the second group beverages mainly are manufactured by well-controlled complex fermentation process which can be traced back to ancient times. This chapter focuses on the production and application technologies of milk-based beverages and discusses the physicochemical properties and health benefits of some milk-based beverages. Also, recent developments and hot consumer trends in milk-based beverages market will be discussed in detail.

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   3

1.2  Production and Characteristics of Some Milk-Based Beverages 1.2.1  Unfermented Milk and Milk Derivatives 1.2.1.1  Flavored Milks/Drinks Flavored milk/drink is a dairy product which has some flavors such as chocolate, cacao powder, fruits, and sugar, often enriched with vitamins and calcium. There is a difference between “flavored milk drink” and “the flavored milk” is owing to their fat contents. While “the flavored milk” term is used for the product which contained a milk fat percentage at least equal to the minimum legal requirement for market milk, but when the fat level is low (1%–2%), “The milk drink” term is used. Flavored milk or milk drinks have mainly been aimed at children. In several countries such as the United States and India, school meal plans contain flavored milks/drinks due to their high nutritional values. Recently, adult-friendly flavors and new packaging design has been discussed for these products in order to broaden the consumer base (Anonymous, 2017a,b,c). Pasteurization or ultra high-temperature (UHT) sterilization process is used in the production of flavored milk and milk drinks. When the sterilization process is used, the shelf life of the product becomes long and can be stored at room temperature (Fig.  1.1). Unlike the pasteurization process, flavored milk and milk drinks can be stored at room temperature after UHT sterilization because the filling of flavored milk or milk drink in sterilized special packaging material or container (laminated cartoon or plastic bottle) is achieved in an aseptic condition. This process prevents recontamination of the products during storage and transport (Anonymous, 2017a,b,c). Chocolate milk is most popular flavored milks/drinks in the world. In general, it contains 2% of fat, cocoa powder (1%–1.5%), sugar (5%–7%), and stabilizer (e.g., sodium alginate—0.2%). In general, pasteurization process for chocolate milk is as follows: standardized milk is preheated to 35–40°C and filtered; or preheated to 60°C, homogenized at 2500 psi. Afterwards, cocoa powder and sugar are slowly added to warm milk and mixed to dissolve them properly. The milk mixture is then pasteurized at 71°C for 30 min, cooled rapidly to 5°C, bottled, and kept under refrigeration (5°C) until used. The fruit flavored milk can be prepared in the same process line. However, some important points should be taken into the account: (a) addition of excessive sweet syrup or fruit syrup should be avoided to get an optimum blend of sweet, fruity, and milky flavors in the product, (b) excessive acid addition should be avoided because of coagulation risk of milk protein. The common flavors for fruit flavored milk and milk drinks are strawberry, orange, lemon, pineapple, banana, and vanilla (Gupta and Kulkarni, 1983; Anonymous, 2017a).

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Receiving milk

Production of milk flavored milk/milk drinks by pasteurization

Production of milk flavored milk/milk drinks by sterilization

Standardization

Cooling to 5°C and bulk storage

Preheating to 35°C-40

Pre heating (60°C) Pre heating(35–40°C)

Filtration/clarification Homogenization (2500 psi) Mixing cocoa or fruit syrup, mixing flavor sugar and stabilizer-emulsifier

Adding cocoa or fruit syrup, mixing flavor sugar and stabilizer-emulsifier

Filling and capping (in cleaned and sanitized bottles)

Mixing procedure Sterilization (108–111°C for 25–30 min) Pasteurization (71°C for 30 min)

Cooling (room temperature)

Bottling and storage (5°C)

Storage (room temperature)

Fig. 1.1  Production of flavored milks and milk drinks (Anonymous, 2017a).

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   5

The addition of some food additives as stabilizers (e.g., alginate, carrageenan) and emulsifiers (e.g., soy lecithin, mono- and diglycerides of fatty esters) in flavored milk and milk drinks is a common procedure. The stabilizer maintains stability of milk proteins to prevent the phase separation and enhanced body and viscosity while the emulsifier reduces tendency of the fat globule to rise and also improves the creamy texture and mouthfeel of the product during storage and transport (Anonymous, 2017c,d).

1.2.1.2  Milk Smoothies/Milkshakes Smoothies are blended beverage which were first introduced in the 1960s and have became more popular in the 2000s owing to their health benefits. They are sold as cold drink, snack, or meal alternative. But, they are not offered at breakfast, lunch, or dinner on the same day. Because, they do not meet the meal pattern requirements for the full fluid milk and fruit/vegetable. It was emphasized that sizes of smoothies be limited to 236.5 mL for elementary school students and 354.8 mL for middle and high school students. Smoothies are composed of raw fruits or vegetables with water, fruit juice and puree, yogurt, milk, or soy milk (Anonymous, 2017e) (Fig. 1.2). They also contain other ingredients such as crushed ice, sugar, honey, grains, herbs, dairy, or vegetable proteins, and enhancers (vitamins, amino acids, and minerals). Smoothies have a higher viscosity than a juice or milk due to their high solids contents and some thickeners such as pectin. Smoothies are consumed fresh or preserved for 1–3 weeks by keeping in the refrigerator after pasteurization or freezing (Balaswamy et al., 2013; Anonymous, 2017e). Different methods and equipments are used to produce smoothies. For instance, a laboratory-scale production flow chart of milk smoothies are shown in Fig. 1.3 (Mehta et al., 2017).

Fig. 1.2  Milk smoothies (A) and milkshakes (B). From http://www. nutricia.ie/products/view/fortini_ smoothie_multi_fibre and http:// www.danonesutluatistirmalik. com/ [Accessed on 30 September 2017].

6  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Cow milk Standardization (3% fat and 8.5% SNF) Addition soy protein isolate, sucralose, and pectin Addition of mango pulp, carrot juice, chickpea flour, honey, trisodium citrate High speed mixing using laboratory blender pH adjustment (pH 4.2) by using citric acid

Fig. 1.3  Laboratory-scale production of milk smoothies. From Mehta, D., Kumar, M.H.S., Sabikhi, L., 2017. Development of high protein, high fiber smoothie as a grab-and-go breakfast option using response surface methodology. J. Food Sci. Technol. 54, 3859–3866, with permission from Springer International Publishing AG.

Heat treatment (65°C for 5 min) Homogenization (120 and 35 kg/cm2) Filling and capping in glass bottles Heat treatment (90°C for 5 min) Cooling and storage at 4°C

Basically, industrial milk smoothies are prepared by high-speed mixing process following homogenization and heat treatment. High-speed mixing process needs some requirements: (a) the mixing system must be able to blend liquids of widely varying viscosities, (b) when frozen solids, hard, or fibrous raw materials are being used, all equipment may be required to chop and purée the solid ingredients, and (c) the mixing system must disperse powdered ingredients such as milk powders, stabilizers, and sugar (Anonymous, 2017d). Similar to milk smoothie, milkshakes are also blended cold dairy beverages. It is usually prepared by milk, ice cream or iced milk, emulsifier and/or stabilizer, and flavorings or sweeteners (e.g., fruit syrup or chocolate sauce). Milkshake contains ice cream unlike milk smoothie. Traditionally, milkshake is served with a whipped cream as topping in a tall glass with a straw. Several fast food restaurants make milkshakes using automatic machines and many dairy companies also produce pasteurized milkshakes as dairy snacks of different size in a plastic container. In automatic machines, a premade milkshake mixture, flavoring agent, and a thickening agent are mixed, frozen, and served at the same time. Chocolate syrup and malt as flavoring agent are mostly used in milkshakes in the United Kingdom. It is called a “Frappe” in parts of New England and Canada. Milkshakes added fruit are popular

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   7

drinks which are called “Batido” in Latin America. Nowadays, most of the companies have developed low-fat and low-sugar milkshakes for children. Dietary fiber and other nutrients such as whey proteins have also been added in premix or packed milkshakes (Anonymous, 2017f ). Industrial process for the production of milkshake involves basic food processes including mixing, homogenization, and high-temperature short-time pasteurization (HTST). Fundamentally, premix or packed milkshake is oil-in-water emulsion and all ingredients are mixed together with different amounts of entrained air (Arbuckle, 1969). Therefore, the quality of milkshake is highly depend on its compositions and processing conditions. A patented chocolate flavored liquid milkshake composition and production process are presented in the following table (Watson, 1968).

Ingredients

Percent by Weight

Butter fat

5.5

Milk solids-nonfat

9.3

Sugar Cocoa Emulsifier (glycerol monostearate) Carrageenan Sodium carboxymethyl cellulose Water Total

9.6 1 0.07

Production Process Mixing all ingredients except carrageenan and cellulose with heating to 160°F Carrageenan and cellulose were slurred in water at 190°F and added into other heated ingredients The mix was homogenized to 2500 and cooled to 50°F Cooled mix filled the cans to a level of 90% of the total volume Canned mix was sterilized HTST at 265°F. For 120 s and cooled at 80°F

0.02 0.01 74.50 100

1.2.2  Fortified Milk-Based Beverages Food fortification is defined as “the addition of one or more essential micronutrients to a food, whether or not it is normally contained in the food, for the purpose of preventing or correcting a demonstrated deficiency of one or more nutrients in the population or specific population Groups” according to the Codex Alimentarius Commission (FAO, 2017). The aim of this practice is, in other words, to increase the content of essential components to a certain level in foods (Sathya et al., 2016). Food fortification not only has a significant impact on the nutritional deficiency/malnutrition and public health problems in adult and children, but also has a role for improving the sensory attributes such as flavor, aroma, color of the food products (Arora et  al., 2014; Sathya et al., 2016).

8  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Milk is a very valuable nutrient due to the presence of high protein and essential amino acids, fatty acids, calcium, vitamin B, and bioactive components, such as lactoferrin, lactoperoxidase, casein, and whey protein. But, milk composition and nutrient levels in milk varied depending on the factors such as the seasonal conditions, feeding type, animal type, thermal processing conditions, etc. (Sharma, 2016; Anonymous, 2017g). As a result of this variation, the nutritional value of milk could not always reach the expected level and fortified/ added with nutrients milk need increases every day as well; fortified liquid milk has become mandatory in several countries. The nutrients permitted for fortification in the milk industry are essential minerals (iron, iodine, etc.), essential fatty acids (long-chain polyunsaturated fatty acid), essential amino acids, vitamins, and co-vitamins (all-trans-retinol, β-carotene, vitamins A, B, D, and E), phytonutrients (dietary fiber), enzymes, probiotics, prebiotics, etc. (Sathya et al., 2016; FAO, 2017). There are many studies and applications on the fortification of milk and milk beverages with different micronutrients in several countries. Fortification with essential minerals began to be routinely used to develop and enhance sensory attributes such as flavor, appearance of milk-based beverage, etc. Dairy-based beverages commonly fortified calcium, magnesium, and iron (Özer and Kirmaci, 2010). For example, a milk-based fruit beverage containing calcium, phosphorous has been consumed in Germany (Arora et al., 2014). In Canada and United States, the fortification of milk, dry milk, evaporated milk, etc. with vitamins A and D is common practice, besides milk and milk powder produced in Chile have been fortified with iron, copper, zinc, and vitamin C to prevent iron deficiency and anemia in infants and children. In addition, iodine-enriched milk and milk products were accepted as main sources of iodine in Europe and the England diet (Phillips, 1997; Hertrampf, 2002; Allen et  al., 2006). Argentina, Guatemala Honduras, and Mexico are other m ­ ajor ­countries that made mandatory the fortification of liquid whole, skimmed, and semi-skimmed milk with vitamins A and D. It was reported that recommended minimum fortification level (IU/L) of vitamins A and D to liquid whole milk was 4500 and 500 IU/L, respectively. Fortifying milk with vitamins/minerals is simple. Most striking point in the fortification is solubility properties of added nutrient in milk and milk beverages. So, it was preferred to have vitamins and minerals in powder form and oil-soluble vitamins in oily form, as well as water-soluble vitamins in dry form, two or more nutrients in premix forming homogeneous mixture can be incorporated into milk and milk products. The fortification must be applied before homogenization and thermal process steps to ensure homogeneous distribution and stability of the fortificant (Anonymous, 2017g).

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   9

Due to the protective effect of omega-3 fatty acids on cardiovascular disease, they have been added to milk and dairy beverages. Some vegetable oils and cold water fish are used for fortification of dairy beverages. Today, several fortified milk beverages with omega-3 fatty acids including Omega-3 (France), Natrel Omega-3 (Canada), Heart Plus (Australia), Dawn Omega Fresh Milk (Ireland), and NaturLinea (Spain) are available in the market (Kelly et al., 2009). It is noted that main drawbacks of enrichment of omega-3 fatty acid of food are oxidation and unpleasant fishy taste. However, several new antioxidants and encapsulation processes have been developed to minimize this problem. In dairy products such as beverages, oxidation problem can solved with storage temperature. It is well known that most of the dairy products are typically refrigerated or frozen. So, lower storage temperatures protect the polyunsaturated fat against oxidation and milk proteins have also been shown to provide protection against the oxidation of added omega-3 fatty acids (Hernandez, 2014). Plant sterols are also defined as bioactive compounds to fortify dairy beverages. It is reported that free and esterified plants sterols have many health effects such as reducing cholesterol absorption and plasma low-density lipoprotein (LDL). Therefore, incorporation of these bioactive compounds in beverages have been studied expansively. Many sterol-enriched dairy beverages such as Flora proactive, Danone-Danacol and Benecol-yogurt drink are available in the marketplace (Alemany-Costa et  al., 2012; Garcia-Llatas et  al., 2015; Nagarajappa and Battula, 2017).

1.2.2.1  Whey Beverages Dairy processing industry, especially cheese production, generates a large amount of whey containing 93%–94% moisture and 6%– 7% solid waste (Russ and Meyer-Pittroff, 2004). The EU statistics on whey powder showed 2.02 million tonnes whey powder production in 2017 and production ratio is estimated to reach 2.32 million tonnes by 2026 (Anonymous, 2017h). It was reported that whey can be used to produce whey powder and to extract lactose and protein. In addition, there are many potential application areas such as production of organic acids such as lactic, acetic, citric, meat, and meat products, ­reduced-fat products, bakery, and confectionery and substrate media to single cell, ethanol, acetaldehyde, and methanol (Zall, 2004; Królczyk Jolanta et al., 2016). Whey proteins have high solubility, mild flavor and neutral taste, pH in the beverage medium, unique nutritional composition and so were suitable for the development of ready-to-drink and milk-based beverages (Chavan et al., 2015). In recent years, a common practice is also the development and production of the whey-based beverages (Russ and Schnappinger, 2007). Whey-based beverages are ­categorized into

10  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

four subgroups (Chavan et al., 2015): mixtures of whey (processed or unprocessed, including UF permeates) with fruit or vegetable juices (rarely); dairy-based “thick” beverages (fermented or unfermented); thirst-quenching carbonated beverages; and alcoholic whey beverages (beer, wine, or liqueurs) (a) Whey beverages blended with fruit juices or vegetable juice These beverages have been produced by mixing fruit juices or concentrates and unprocessed or deproteinized whey or UF permeates. Citrus fruits (orange, lemon, etc.), tropic fruits (mango, passion fruit, etc.), and other fruits such as banana, apple, pear, and berries are often preferred as flavor masking agents in cooked milk and for mild salty taste of whey proteins. In addition, some sweeteners such as vanilla and honey have been used to improve the taste of beverages (Djurić et  al., 2004; Jeličić et  al., 2008). It was reported that different types of vegetables or their juices (carrot and tomato) were used in the preparation of whey-based beverage. Production procedure was defined as mixing of two main phase and then fats pasteurization and bottling/packaging (Webb, 1938). Castro et al. (2013) prepared a strawberry-flavored probiotic dairy beverage (2% v/v Lactobacillus acidophilus), supplemented with different whey concentrations (0%, 20%, 35%, 50%, 65%, and 80% v/v). It was found that the fragility of the gel structure increased with increasing whey content in the formulation, however, sensory quality and consumer acceptance decreased with whey contents greater than 65% in the formulation. In another study by Koffi et al. (2005), some physicochemical properties of banana-flavored whey beverage were investigated during 60 days storage and sensory analysis was also carried out on all beverage samples at seventh day and sixtieth day of storage at 4°C. Researchers reported that color, sedimentation, and serum separation values were important quality parameters for monitoring storage stability during 60 days at 4°C and developed whey-banana beverages could be stored for 60 days at 4°C. (b) Dairy-type whey beverages Dairy-based whey beverages production technology comprised deproteinization of whey, concentration of whey, and then lactose fermentation with yeast strains Kluyveromyces and Saccharomyces, addition of sucrose, alcohol fermentation, flavoring/sweetening, and packaging (Pescuma et al., 2008). Kefir-like beverages were developed using substrates such as cheese whey and deproteinized cheese whey (Magalhães et  al., 2011a). Cheese whey powder solution and deproteinized cheese whey powder solution (obtained by autoclaving followed by aseptic centrifugation of the cheese whey powder solution) are used as fermentation media. Researchers showed that cheese whey powder and deproteinized cheese whey powder were suitable as substrate and fermentation media for the

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   11

production of kefir-like beverages. In addition, kefir grains could be cultivated in the cheese whey powder and deproteinized cheese whey powder solutions and produced similar rates of ethanol (7.8– 8.3 g/L), organic acids such as lactic acid and acetic acid (5.0 and 0.7 g/L, respectively), and volatile compounds (alcohols, ester, and aldehyde) to milk kefir beverages. Legarová and Kouřimská (2010) evaluated the sensory quality of whey-based beverages produced using semi-skimmed milk (25% and 50% added value) and commercial yogurt bacteria. Although, the addition of yogurt culture has no significant effect on sensory attributes of the beverage samples, the addition of semi-skimmed milk provided the desired sensory scores to flavor, appearance, and color of beverage. Supplementation with functional and/or bioactive components for the development of whey-based beverages has been reported several times by different researchers in various studies and provided different scheme for the production (Seyhan et al., 2016; Djurić et al., 2004; Tripathi and Jha, 2004). For example, a laboratory-scale production flow chart of probiotic whey beverages with added soy isoflavones and phytosterols is depicted in Fig. 1.4. (c) Whey-based thirst-quenching carbonated beverages The high-pressure addition of CO2 to beverages causes the refreshing effect and also contributes to the improvement of the drink flavor. Carbonated whey-based beverages began to reach the beverage market. Rivella (a sparkling contain deproteinized whey, lactic acid bacteria (LAB), sugar and flavor agent), Bodrost (an alcoholic beer contain clarified whey, sugar, and raisin), Tai (a soft drink contain whey protein concentrate) are widely known commercial carbonated wheybased beverages (Lenkov, 1969; Barth, 2001). (d) Alcoholic whey beverages Whey or whey permeate added with strains Kluyveromyces fragilis or Saccharomyces lactis were suitable for the production of low alcohol content (less than 1.5%) beverages such as whey-based beer, wine, champagne. However, mineral and lactose contents of whey are important quality properties to obtain desired beer color and the flavor, fat content of whey can cause undesirable results in the formation of beer foam (Jeličić et al., 2008; Wendorff, 2008) Seyhan et al. (2016) studied the development of whey-based beverages containing whey powder and functional components such as soy isoflavones or phytosterols and probiotic Lactobacillus strains. Researchers reported that all the added functional components have no significant effect on the beverage composition and ­especially, whey-based beverages that contain phytosterols had high sensory scores such as overall perception and aroma/flavor than beverages that contain isoflavones at the end of the 28-day storage period.

12  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Reconstituted 70% demineralized whey (~7% dry matter, pH 6.5)

Adding nutraceuticals (w/v)

Soy isoflavones

Phytosterols

0.00% 0.25% 0.50% 1%

0.00% 0.25% 0.50% 1%

Stabilizer addition (0.7%, w/v) K-carrageenan and xanthan gum (70:30)

Heat treatment (85°C for 15 min)

Fig. 1.4  A laboratory-scale production flow chart of probiotic whey beverages with added soy isoflavones and phytosterols. From Seyhan, E., Yaman, H., Özer, B., 2016. Production of a wheybased functional beverage supplemented with soy isoflavones and phytosterols. Int. J. Dairy Technol. 69, 114–121, with permission from John Wiley & Sons, Inc.

Adding starter culture (Lactobacillus acidophilus LA-5 and Lactobacillus casei LBC-81, 1%, v/v)

Incubation (37 ± 1°C for 18 h)

Sucrose addition (5%, w/v)

Mixing and bottling

Storage (28 days at 4 ± 1°C)

1.2.3  Fermented Milk Products 1.2.3.1 Kefir Kefir is a fermented dairy product commonly produced in Russia, Eastern Europe, and certain countries in Asia. Lactic acid and alcohol fermentations cause the development of characteristic kefir flavor, including yeast aroma and alcohol content. Carbon dioxide produced by yeast in kefir induces fizz sensation on the tongue. Traditionally, kefir is produced from kefir grains. The grains are small, cauliflower-­ shaped, and semihard particles that contain a balance of bacterial and

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   13

yeast microorganisms. Kefir grain, curd-like polysaccharide matrix, which is filtered off after use, is used to produce kefir. The kefir grain can be reused for a number of batches. Typical kefir grain contains bacteria such as Lactobacillus kefir, Lactobacillus kefirogranum, and species of leuconostocs, lactococci, and lactobacilli, and yeasts such as Saccharomyces kefir, Candida kefir, and Torula spp. After pasteurization of milk at 85°C for 30 min, milk is cooled to 22°C and inoculated with kefir grains and incubated until 4.6 pH for 12–16 h. Acetaldehyde, diacetyl, ethanol, lactic acid, and acetone are typical flavor compounds in kefir. Trace amount of alcohol is also produced by yeasts (Guzel-Seydim et al., 2010; Chandan, 2013).

1.2.3.2 Koumiss Koumiss is a traditional fermented drink of Normand cattle breeders and popular food in Mongolia, Kazakhstan, Kirgizstan, and some regions of Russia. It is made from mare’s milk as a result of lactic acid and alcoholic fermentation (Wang et al., 2008). Cow milk can also be used to produce koumiss, but need some modification specifically in the composition (need removal of fat and addition of saccharose) (Yaygin, 1992). Koumiss is produced by using Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus, and Torula yeasts. Because of low protein content of mare milk (2%), no curd occurs in the product. Lactic acid, ethanol, and carbon dioxide play role in the foamy appearance of Koumiss (Chandan, 2013). In the production of Koumiss, pasteurized mare’s milk or modified cow’s milk is cooled to 25°C. Then starter culture is inoculated into the milk for fermentation, completed at about 4.6 pH. Frequent agitation of the product during fermentation is a crucial step for desirable quality characteristics for the product (Yaygin, 1992).

1.2.3.3 Ayran Ayran is a yogurt-based, salty drink, commonly consumed in Asia, Middle East, and Arab countries. It is made by mixing ­yogurt with water or water is added into milk and then stirred, yogurt making procedure is followed. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (yogurt bacteria) are used as starter culture for ayran production. Total solid content should not exceed 11%. After completion of fermentation, 0.5%–1.0% table salt is added to the product. Then yogurt is mixed until a homogeneous and drinkable product is obtained (Kocak and Avsar, 2009; Özer, 2006).

1.2.3.4 Buttermilk Buttermilk is originally the fermented by-product of butter manufacture. However, today skimmed or whole milk is used to produce cultured buttermilks. Two types of cultures were used for

14  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

­fermentation: lactic acid producers—Lactococcus lactis subsp. cremoris and Lactococcus lactis subsp. lactis, flavor (diacetyl) producers—­ Leuconostoc mesenteroides subsp. cremoris. Heat treatment is applied at 95°C and then milk is cooled to 20–25°C before inoculation with starter culture. Fermentation proceeds for 16–20 h until acidity of 0.9% lactic acid (White, 2013; Yildiz, 2010).

1.3  Nutritional Quality and Health Benefits of Milk-Based Functional Beverages The increasing society quest for healthy, natural, and organic life induces growth of the food industry. Beverage industry containing functional ingredients, fortified water, teas, energy, and sports drinks has importance in the food industry market (Bogue and Troy, 2016; Vartanian et al., 2007). The size and variety of products in functional food marketing are steadily increasing every day. Probiotic yogurts, lactose-free milk, gluten-free food, beverages containing gingko and ginseng extract, edible oils enriched with omega fatty acids, low-­ calorie foods, low sodium salts, diabetic foods, etc. are among the most popular functional products for consumers who have food allergies or the healthy living habits. Milk is a very valuable nutrient containing several bioactive components (Fig.  1.5). These bioactive components can be used for the preparation of supplements/products for people with special dietary needs (athletes, pregnant women and infant nutrition, gastric and phenylketonuria patients, etc.) in medical and pharmaceutical industry, as well as they have important nutritional value in addition to health benefits of milk or milk products. Glycomacropeptides, lactoferrin, lactoperoxidase, casein and whey protein hydrolysates, α-lactalbumins, caseinophosphopeptide, and milk minerals are the examples of milk-based bioactive components. It was reported that bioactive component levels in milk and milk products varied depending on the factors such as the milk type, production method, thermal processing conditions, etc. In addition, milk and milk products are not only appropriate medium containing bioactive components, but also for the transport of nonmilk-based bioactive components with different characteristics (Sharma, 2016). Milk-based beverages are increasingly consumed due to their functional and nutritional properties and several health benefits provided by their ingredients (Granato et al., 2010; Farah et al., 2017). In the recent years, milk products with “low” claims such as “low fat,” “low carbohydrate/lactose,” “low cholesterol,” and “low calories” offer new opportunities to the dairy industry. Especially, milk-based and fermented beverages are preferred to low fat, lactose, cholesterol,

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   15

Bioactive ingredients from milk Milk

Early lactation milk Colostrum powder Separation

Fractionation

Cream separation Cream

Anhydrous milk fat (AMF)

Fat globule membrane material

Milk fat globule membrane (MFGM) Phospholipids Enzymes Membrane proteins Mucins Glycoproteins

Casein hydrolysates

Skim milk

Acid

Acid casein

Rennet

Immunoglobulins Lactoferrin Lactoperoxidase Insulin-like growth factors (IGF-1) Transforming growth factor beta-2 (TFG-β2) Growth hormones Lysozyme Cheese/rennet casein

Acid whey

Sweet whey

Hydrolysis

Glycomacropeptide (GMP)

Hydrolysis

Fractionation

Casein peptides Lactose

Whey protein hydrolysates

Colostrum

Whey peptides

Oligosaccharides

Milk minerals Milk calcium

β-Lactoglobulin α-Lactalbumin Bovine serum albumin (BSA) Whey growth factors (WGF) Lactoferrin Mucins Immunoglobulins

Fig. 1.5  Bioactive components in milk (Sharma, 2016). With permission from CRC Press.

c­ alories, etc. and also as delivery vehicles such as bioactive or functional supplements (Sharma, 2016). Dairy industry includes the most preferred products for consumers who desire natural and healthier living habits. However, alternative and novel dairy-based products that contain nutraceuticals and bioactive functional ingredients continue to be developed day after

16  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

day. Recent years, production and consumption of the fermented milk products and beverages such as yogurt drinks, kefir, koumiss have attracted attention due to their contents which have several health claims such as insulin-like growth factors, epidermal growth factors, broad-spectrum antimicrobial effect, anti-inflammation effect, antioxidant agent, immune-enhancing effect, binding of cholera and Escherichia coli enterotoxins, and iron (Uruakpa et al., 2002; Davidson et  al., 1989; Stephan et  al., 1990; Kussendrager and van Hooijdonk, 2007; Kawasaki et al., 1992; Mulder et al., 2008), reducing allergenicity and antigenicity impacts (Sinha et al., 2007), and decreasing blood pressure (Özer and Kirmaci, 2010; Fluegel et al., 2010). Many research and review articles have been published highlighting dairy-based beverages enriched with dairy or nondairy functional and bioactive components (Malbaša et  al., 2009; Cilla et  al., 2012; Rodríguez-Roque et al., 2014; Garcia-Llatas et al., 2015; Fiorda et al., 2016; Farah et  al., 2017; Turchi et  al., 2017). Some brands such as Danone Activia and Actimel (probiotic milk drink with Bifidus strain and natural drinkable yogurt with Lactobacillus casei Danone cultures, respectively), Yakult (probiotic milk drink with L. casei Shirota), Yoplait Petits Filous Frubes Drinks (drinkable yogurt with lactic cultures), Nestle Bliss (drinkable yogurt with L. acidophilus, Bifidobacterium lactis, and S. thermophilus) developed milk-based beverages aimed at both children and adults. Similarly, yogurt drinks as Früzinga (high fiber and vitamin D fortified drinkable yoghrt), Flora proactive (plant sterol esters (3.5%) fortified drinkable yogurt), Muller little stars (drinkable yogurt with calcium and vitamin D) including other bioactive components as well as probiotic cultures have made a reputation in the milk-based beverage market. Addition of mainly functional ingredients as whey, fruit juice, probiotic bacteria, and prebiotic to milk-based beverages has been a significant factor in the increasing the demand for the development of functional dairy beverages. There have been several publications on the health promoting effects of phytosterols, a minor constituent in vegetable oils, in the literature (Schwartz et al., 2008; Baumgartner et al., 2017; Jacek et al., 2017). It was clinically proven that phytosterols have LDL cholesterol lowering effect which reduces the absorption of cholesterol from the gut and may reduce the risk of heart disease. In addition, FDA approved the claims that food products containing at least 0.65 g of phytosterol/­ stanol esters or 0.4 g free phytosterols/stanols per serving have the heart health benefits in 2003. Vegetable oil-based spreads/margarines, cereal products such as corn flakes and bread, etc. supplemented with phytosterols/stanols are in demand in the functional foods market. Milk products such as low-fat yogurt, fat-free milk, especially milkbased beverages formulated with plant sterols/stanols have started to appear in dairy marketing and these products’ enrichment with

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   17

plant sterols is allowed in the European Community (EC) (Decision 336/2004/EC) (Anonymous, 2009; Garcia-Llatas et al., 2015; Sharma, 2016). For example, Benecol yogurt drinks (contain 3% plant stanol esters of total drink), Danone Danacol dairy drinks (contain 1.6% plant sterol esters of total drink), Flora ProActiv yogurt drink (contain 3.5% plant sterol esters of total drink), and ASDA Yogurts Drink (contain 3.4% plant sterol esters of total drink) are popular milk-based flavored beverages enriched with several amounts of plant sterols. Garcia-Llatas et al. (2015) evaluated the in vivo (serum sterol concentrations) and in vitro (bioaccessibility values using simulated gastrointestinal digestion) effects of consumption of phytosterol-­enriched milk-based fruit beverages. Clinical studies performed on postmenopausal women showed that statistically significant reduction in serum sterol levels due to consumption of milk-based fruit beverages (contained in 1.5-g phytosterol/day) and reported that milk-based beverages were suitable foods for enrichment with plant sterols and plant sterols intake into the body. Kefir, koumiss, acidophilus milk, bifidus milk, whey-based beverages are milk-based fermented products consumed by the people from different parts of the world for many years and also their consumption is becoming increasingly popular. While some of these drinks are preferred by consumers with private health conditions, some of these are important part of the traditional diet habits. Kefir is defined as self‑carbonated, viscous, and sour/acidic taste fermented milk beverage produced by cow or goat milk. Small and irregular-shaped kefir grains containing various LAB (Lactobacillus, Lactococcus, Leuconostoc, Acetobacter, etc.), lactose-fermenting, and nonlactose fermenting yeasts (Kluyveromyces marxianus, Saccharomyces unisporus, Saccharomyces cerevisiae) have important effect during the kefir production (Güzel-Seydim et  al., 2000; Anonymous, 2011; Magalhães et al., 2011b; Sherkat et al., 2016). Although kefir has been recommended and consumed in Central Asia due to healthy lifestyles and their therapeutic effect for thousands of years, it is still popular today. According to Codex Standard for fermented milks (Codex STAN 243-2011), kefir should contain at least 2.7% milk protein, less than 10% milk fat, a minimum of 0.6% titratable acidity (as lactic acid equivalent), and 107 and 104 CFU/g LAB and yeast, respectively (Anonymous, 2011). Researchers have published several articles on kefir-containing components that have valuable health benefits. It was reported that one cup of kefir (approximately 250 mL) contains 8–11 g of protein, which have high digestibility and biological value. In addition, kefir has been accepted as a good source of vitamin B (thiamin, riboflavin, pantothenic acid, cobalamin), minerals (86–160 mg calcium, 150– 165 mg potassium, 50 mg sodium/100 mL kefir), bioactive peptides,

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essential amino acids such as tryptophan, threonine, serine, lysine, and CLA (Guzel-Seydim et al., 2006; Sherkat et al., 2016). Kefir is a preferred drink for people who have lactose intolerance and cannot digest milk products, because it has lactose content lower than the milk (Farnworth, 2005). It has been reported that essential amino acids and bioactive peptides in kefir strengthens the immune system (GuzelSeydim et al., 2010) and have relaxing effect on the nervous system (Lv and Wang, 2009). Antimutagenic, anticarcinogenic, and antimicrobial roles of kefir microflora are positive health effects most cited in the literature (Ahmed et al., 2013; Leite et al., 2013). In addition, regular kefir consumption induces reduction in the serum glucose and cholesterol levels and helps in the protection against toxins and inhibition of Helicobacter pylori (Ahmed et  al., 2013; Nielsen et  al., 2014). Koumiss is a fermented milk beverage produced from mare milk by lactic acid and alcoholic fermentation in locally central Asia and Russia (Akuzawa and Surono, 2002). Koumiss consumption has been advised due to functional health benefits Marsh et  al. (2014) reported that koumiss was used for the treatment of some chronic diseases such as tuberculosis, asthma, and for the prevention of cardiovascular and gynecological disease risk factors. In addition, koumiss is very valuable and unique milk-based beverage due to composition of mare’s milk in which raw material of koumiss is similar to mother’s milk (GuzelSeydim et  al., 2010). Koumiss has calcium, phosphorus, niacin, and total amino acid (168, 137, 1.06, and 2.19 g/100 mL koumiss, respectively) higher than kefir. Especially, it was observed that vitamin C content is 10 times more (10–25 mg/100 mL koumiss) when compared with that of kefir and yogurt drink (ayran) (Sherkat et al., 2016). It also has noteworthy health benefits, that is, it has an ideal calcium:potassium ratio (2,1 w/w), high PUFA, and cholesterol-lowering contents (Kinik et al., 2000). Drinkable yogurt called “ayran” is very popular traditional beverage in Turkey as well as in other countries such as Greece, Bulgaria, Romania, etc. and in the Balkan and Azerbaijan, Armenia in Caucasus regions in almost every season. Ayran is preferred frequently by people who diet due to low oil and calorie contents and consumed in larger amount than yogurt. In addition, nutrients such as proteins, essential amino acids, vitamin B, major and minor minerals in yogurt has important components that contribute to its functional benefits (Sherkat et al., 2016). Chen et al. (2014) reported that ayran is also suitable for weight management and constipation treatment. In addition, it was shown that one cup of ayran intake per day decreases the risk of type 2 diabetes. Koumiss/airag was produced from mare milk by spontaneous fermentation in central Asia and Russia. Regular consumption of koumiss was reported to be effective in increasing body weight, ­energy, and

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   19

also in the prevention and treatment of several diseases such as tuberculosis, asthma, pneumonitis, cardiovascular diseases, gynecological diseases, and cancer (Marsh et  al., 2014; Kanareikin, 2016). Acidophilus-Bifidus milk is a fermented dairy beverage produced by L. acidophilus and Bifidobacterium ssp. cultures with 1:1 bacteria ratio. Acidophilus milk and bifidus milk can be manufactured separately by using different culture inoculation rates and fermentation conditions; these fermented milk beverages are preferred by consumers because of their high digestibility and beneficial effects in gastrointestinal system diseases, especially constipation (Yerlikaya, 2014). Rodríguez-Roque et  al. (2014) investigated the influence of a blended fruit juice beverage and milk-based blended fruit juice beverage formulation on the in vitro digestibility and bioaccessibility of bioactive components of fruit juice. Although milk-based blended fruit juice beverage has high bioaccessibility to oil-soluble bioactive compounds such as carotenes, and xanthophylls, it was determined that the blended fruit juice beverage without milk has the highest bioaccessibility values to hydrophilic substances such as phenolic compounds and vitamin C. Considering the fact that both milk and fruit juice are valuable source of bioactive nutrients, it was thought that development of milk-based fruit juice beverage has induced improvement in the in vivo and in vitro bioaccessibility and bioavailability of bioactive substances. In another study, bioaccessibility of bioactive substances that contain milk-based and soy-based fruit beverage formulations were evaluated (Cilla et al., 2012). Researchers found that ascorbic acid bioaccessibility in soy-based fruit beverages (13%) were less than that in milk-based fruit juice beverages (68–71%). It was also reported that milk fat content has effect on the bioaccessibility of carotenoids and bioaccessibility increases with increasing fat content in milk. Fiorda et  al. (2016) studied the development of probiotic beverages containing bioactive ingredients such as soybean hydrolyzed extract, colostrum, and honey-media inoculated by kefir grains. It was found that these functional beverages, especially beverage added with honey-media, were higher in sensory scores, antioxidant capacity, and protection effect on DNA damage than kefir produced using traditional method. Flavored milk-based beverages with different flavors have attracted the attention at both beverage and milk products market of consumers who are in search of a different flavor. Despite chocolate or cacao flavor being one of the most popular flavors, their high calorie content has raised public-health concerns. So, low-calorie milk-based beverages formulated using fat substitutes and sweeteners have been developed (Yanes et al., 2002). Milk-based beverages formulated with fruit juice and pulp residue rich in dietary fiber, flavonoids, vitamins C, E, and B have become the most widely consumed functional beverages

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and began to take place among the products on sale in the market. Some beneficial properties such as nutritional value of milk, the antioxidant and polyphenolic contents of fruit juice, low-calorie content, etc. have important effects on the market potential of these beverages. It was reported that both milk products and fruit juice could prevent some types of cancer and diseases such as cardiovascular, diabetes, alzheimer, etc. (Janeth Rodríguez-Roque et al., 2013; He et al., 2015). It should be noted that polyphenol-protein interactions may occur when preparing the milk and fruit juice blends. These interactions cause decrease in bioavailability of main nutrient components (polyphenol and protein, respectively) of fruit juice and milk. Many studies conducted on foods and beverages such as fruit, coffee, tea, etc. in polyphenolics have reported that the blending with milk or milk products had a negative impact on the antioxidant capacity or free radical-scavenging ability of phenolic contents (Arts et al., 2001; Tadapaneni et al., 2012). On the contrary, some researchers have observed that milk proteins did not lead to inhibition or decrease in antioxidant ability of polyphenols (Dupas et al., 2006; Keogh et al., 2007; Zulueta et al., 2009). Donkey milk is increasingly gaining attention as a novel source of nutraceutical components such as antibacterial agents and lysozyme, etc. and due to its higher lactose, whey protein, and nonprotein nitrogen contents than those of cow milk. Because donkey milk composition (in terms of high lactose and low casein contents) is very close to human milk and has low casein content (0.64%–1.03% and 0.32%– 0.42% for donkey milk and human milk, respectively), it is preferred for infant feeding and children with cow’s milk protein allergy (Guo et al., 2007; Perna et  al., 2015; Turchi et  al., 2017). Additionally, compared with the cow milk fat content (3.5%–3.9%), donkey milk has approximately 5–10 times less fat content (0.3%–1.8%) (Perna et al., 2015). And so, it is also suitable as protein source to low-calorie diets (Guo et al., 2007). The usages of Lactobacillus plantarum and S. thermophilus for designing a donkey milk-based beverage were evaluated in a study by Guo et al. (2007). Researchers reported that L. plantarum isolates was suitable to acidify donkey milk-based beverage and L. plantarum together with S. thermophilus can be used for the development of donkey milk-based-fermented beverage. There are studies on the effect of different starter cultures in the production of milk-based beverages. Kombucha has beneficial effects on human health (Greenwalth et al., 2000). So, it was thought suitable for the development of functional milk-based fermented beverages. Malbaša et al. (2009) evaluated the usage (10% and 15% added ­levels) of different types of kombucha containing yeast and bacteria in symbiotic relationship for the development of milk-based beverage. In addition, physicochemical and sensory properties of this novel beverage were compared with traditional yogurt and Kefir as control groups.

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   21

Researchers have reported that milk-based beverages produced by Kombucha starter cultures have higher dry matter (%) and protein contents (%) and lower acidity value (%) than yogurt samples. There were few noteworthy differences between sensorial scores of yogurt and kombucha-based beverage samples after production. Omega-3 fatty acids content, antioxidant, and antimicrobial activities of different essential oils obtained from various plants and spices (rosemary, sage, oregano, thymus, black pepper, cinnamon, coriander and cumin, etc.) have been investigated by several researchers (Chorianopoulos et al., 2005; Bozin et al., 2007; Neffati and Marzouk, 2008; Bag and Chattopadhyay, 2018). In a study by Boroski et al. (2012), the dairy beverages produced by skimmed milk powder enriched with linseed oil were supplemented with omega 3 fatty acids-rich oregano extract and oregano essential oils at three different concentrations (0.001, 0.01, and 0.1 g/100 g in the beverages). All supplemented milkbased beverages were tested to determine their antioxidant capacity and oxidative stability under different storage conditions. It was found that supplementation has no significant impact on the physical stability, although oregano extract and its essential oil are very rich in unsaturated fatty acids. Dairy beverages supplemented with oregano extract have higher oxidative stability than that supplemented with oregano essential oil. According to the findings of the study, it can be revealed that milk-based beverages are favorable matrix to enrichment of foods in terms of omega fatty acids. Although milk and milk products, especially milk-based beverages came up as appropriate popular products enriched with bioactive components, sometimes it can face challenges due to characteristics, solubilities, sensory properties, and stability of bioactive components in milk beverages. Some bioactive components such as probiotics, vitamin D, omega fatty acids are sensitive to heat, oxygen, daylight, and medium pH; some bioactive components such as phytosterols, dietary fiber, and calcium have shown low solubility, suspension, and sedimentation in polar mediums; some bioactive components such as peptides and antioxidants can cause undesirable sensory taste/flavor such as bitterness, beany taste, etc. (Sharma, 2016).

1.4  Recent Development and Hot Consumer Trends of Milk-Based Beverages Milk is a valuable food that enters our lives with breast milk and forms the basic nutrients of human diet. It provides health benefits with its high-quality protein contents and is a good source of various kinds of vitamins, essential fatty acids, phosphorus, magnesium, potassium, zinc, and calcium contents. A vast number of studies have confirmed that the milk and milk-based products are very ­important

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to meet the suggested daily intake of components considered to be nutritionally important. The amount of milk recommended to be consumed for a healthy and balanced diet depends on age, sex, and physiological status (Li et  al., 2014; Sharma, 2016). Recently, by the consumers, there has been an increasing interest for a healthy diet and preference for natural ingredients and nutritional aspects of foods and beverages. Such considerations affect the consumer’s preferences for food and offer a substantial potential for the formation of functional food market. Food formulations have been directed to products with high-nutritional value and having health-promoting effects supported by research findings (Wildman and Kelly, 2007; Corbo et  al., 2014). In particular, functional beverage market is definitely the most active food category due to its convenience since it is possible to satisfy the demand of consumers in terms of packaging, contents, size, shape, appearance, distribution, refrigerated storage, and shelf life. Furthermore, they can perfectly carry the desired nutrients and bioactive compounds (Corbo et al., 2014). The global sales of beverage market was predicted to be worth approximately US$1347 billion in 2017 (Bogue and Troy, 2016). Now, the consumers demand products that are inherently innovative and has improved functionality. By 2022, the health benefits associated with functional foods and beverages are expected to drive the growth prospects for the global functional foods market. According to Statista, this market category generated a global sales worth 258.8 billion US dollars in 2014 and was estimated to reach 377.8 billion US dollars by 2020 (Brogie, 2017). In growing markets such as Latin America, Brazil, China, and Asia Pacific where the companies can successfully create innovations by beholding the global consumer tendencies, studying local consumers and diversifying their products from competition, there are substantial possibilities for food and beverages (Bogue and Troy, 2016). Although increased choices in the beverage category exist, dairy beverages have a growing importance in the markets all over the world since they are widely available and have superior nutrition, flavor, and convenience. Dairy foods and beverages constitute almost 40% of the functional beverage market globally and up to 70% in some European countries (Sharma, 2016).

1.4.1  Hot Consumer Trends of Milk and Milk-Based Beverages Recent reports have demonstrated that there is an increase in the number of plant-based milk products versus milk-based products on the market in response to consumers’ growing interest in them. Many grocery stores and restaurants now offer nondairy options to milk such as soy, coconut, rice, almond, and quinoa milks. Preliminary wholesale dollar sales projections for the nondairy milk category peaked at

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   23

$1.2 billion in 2014 according to research by Beverage Marketing Corp (Anonymous, 2015a). In recent years, retail trades of fluid milk have undergone a substantial change and consumption per person has declined in United States at a rate of 830 mL per year since 1975. Between 2011 and 2014, fluid milk sales have dropped 3.8% but nondairy, plant-based beverage sales have increased 30% between 2010 and 2015 (McCarthy et al., 2017). If the dairy industry wants to maintain and increase its market share of total beverage sales, it is important to evaluate and understand factors affecting consumer’s purchase both milk and milk-based beverages. In this sense, several methodologies have been used to understand consumer’s perception and provide insight into factors such as consumers liking and purchase intent of dairy beverages which are the most important and why they are important as they relates to their personal life (Kim et al., 2013; Li et al., 2014; Liutkevicius et  al., 2016; Farah et  al., 2017). Researchers from North Carolina State University used surveys, conjoint analysis, and means-end-chain analysis to uncover the underlying values among dairy milk and nondairy beverage consumers. The results of the study highlighted the most important factors for both milk and nondairy beverages, which were the same: they must be healthy and taste good (McCarthy et al., 2017). In a recent study, researchers have shown that intrinsic characteristics (sensory attributes) play an important role for differentiation and choice of fermented dairy products by consumers followed by extrinsic characteristics, including psychological aspects (emotions and feelings), perception of benefits, health claims, and marketing appeals (Esmerino et al., 2017). Kim et al. (2013) performed a consumer acceptance test and then a combined analysis of US chocolate milk. This study disclosed that the stated fat content (specifically a lowered fat claim) in chocolate milk affects the consumer preference for purchase of the product in a positive way and this is consistent with the previous studies. Li et al. (2014) tried to understand the motivation behind the parents when they buy chocolate milk for their children to aid producers in targeting extrinsic properties that appear attractive to parents while purchasing chocolate milk. According to this study, while buying chocolate milk for their children, the parents remark positive emotions such as satisfied, good, good natured, happy, and lovely. Second to fat content, while buying chocolate milk for kids, the type of sweetener used was the main motivation for selection. While buying chocolate milk for their children, the lowered fat and sugar as well as a label indicating all natural ingredients and added vitamins, minerals, and proteins are found to be attractive to most of the parents as reported by the same researchers. For instance, Chr. Hansen produced a drinking yogurt for kids, which contained 5% added sugar as compared to the market standard of 10%. This reduction was achieved by using milder strains which lead to the formation of lower acidity

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(Searby, 2012). Protein had universal appeal for both milk and nondairy beverages, with higher utility scores for higher levels of protein content (McCarthy et  al., 2017). The rising interest of people in the “high-protein” attribute has been one of the primary areas of study in novel product development in milk beverage industry. Currently, dairy industry has been taking advantage of this trend in terms of creating protein-rich functional products and adding value to proteins for use in a variety of applications (milk, yogurts, whey, and buttermilk drinks) relating to health and nutrition and medicine (Allgeyer et al., 2010; Granato et  al., 2010; Akin and Ozcan, 2017). In the beginning, performance was the main focus of interest for protein beverages in the milk beverages market. For example, the market‑leading Muscle Milk protein beverage of Cytosport, Sprout Foods’ Morning Protein Smoothies, Plus Protein Dairy Beverages from retailer Safeway and Dean Food’s TruMoo Protein Milks are some examples in the United States. In Europe, recent releases include Lactel’s protein-enriched milk drink Sporteus in France that is stated as a sports beverage; in Germany, the leading US protein shake Muscle Milk Protein; and Austrian dairy company Nöm’s Protein Drink option that is an extension of its fasten flavored milk range (Searby, 2012; Anonymous, 2015b). Furthermore, milk proteins (mainly; caseins, a-lactalbumin, b-lactoglobulin) are considered to be the major source of bioactive peptides (BAPs) with a large variety of functional properties such as antihypertensive, antithrombotic, antimicrobial, antioxidant, immunomodulatory, antipyretic, and anticarcinogenic activities. As a ­consequence, they contribute more in maintaining consumer’s health and well-being. Among different food matrices, fermented milk beverages such as yogurt drinks, sour milk, and kefir have already been reported to be attractive source of the BAPs and some of them have been shown to confer health benefits (Hafeez et al., 2014; Marsh et al., 2014; Freire et  al., 2017). A commercial brand Evolus (Finland) and Calpis (Japan) are examples of functional milk beverages that contain an increased number of bioactive peptides derived from milk proteins. Also, antihypertensive properties of such beverages have been shown clinically (Prado et al., 2008). Owing to the worldwide food shortage problems, people are trying to find alternative protein sources especially in developing and underdeveloped countries. Supplementation of food products with microalgae (Spirulina and Chlorella) which contain high-quality proteins as well as antioxidant components, amino acids, minerals, unsaturated fatty acids, and many types of vitamins has been a sustainable way of creating new products for the functional dairy market. Also, it looks like addition of microalgae into probiotic fermented milk promotes growth, increases viability and acid production of probiotic bacteria which is favorable in technological view (Beheshtipour et  al., 2013). Besides, microalgae contained

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   25

in fermented milks can influence the flavor characteristics of the final product. Therefore, the sensory attributes of foods enriched with microalgal biomass may be improved by the aid of methods such as microencapsulation or the addition of flavorings (Corbo et al., 2014). The utilization of food and dairy industry by-products (whey, buttermilk, etc.) such as functional ingredients in milk beverages have lead to the generation of new functional beverages over the last years, with whey being the most remarkable example (Gallardo-Escamilla et al., 2007; Mellema and Bot, 2009; Gad et al., 2013). Whey proteins have unprecedented nutritional and functional properties which can be examined to provide high protein products to consumers. Magalhães et  al. (2010) produced a fermented beverage using kefir grains by substituting milk with whey and stated that the new beverage could be characterized as probiotic since several yeasts and bacteria of Lactobacillus genus were detected. In another study, researchers tried to use mango fruit to enrich whey beverages as mango is a source of vitamins and other phytonutrients, such as antioxidant pigments (carotenoids, such as the provitamin A compound, β-­carotene, lutein, and α-carotene) (Gad et  al., 2013). Such beverages contain extreme calorie per volume and therefore may be useful where food insufficiency problem exists. Moreover, since butermilk’s unique composition comprises minerals, vitamins, lactose, and milk proteins (caseins and whey proteins) in the same proportion as skimmed milk and at the same time its phospholipid content is approximately eightfold higher, there is a high scientific interest on buttermilk (­Jiménez-Flores et  al., 2009). Buttermilk may be considered to be one of the oldest acid milk-based beverages. While it was a by-product derived during butter production in the past, nowadays it is derived by processing skimmed milk. The milk is homogenized, pasteurized (which increases the viscosity of the end product), acidified to pH ∼ 4.5 with a buttermilk culture, stirred until smooth, and packed (Mellema and Bot, 2009). Liutkevicius et  al. (2016) developed a technology for the production of a functional fermented ­ buttermilk-based beverage that is enriched with milk protein concentrate (MPC) of the product and determined its influence on human health. Accordingly, the beverage which contains the buttermilk-skimmed milk-milk protein concentrate (0.3%) as a product had a preferred quality characteristics (regarding syneresis, viscosity, sensory properties, and acceptability). Then, with respect to its effects on human health, it was used for further studies. After a 21-day consumption of the fermented buttermilk beverage containing MPC the medical nutrition experiments did not show any statistically significant effect on the biochemical blood parameters of 25 young volunteers, although some of the parameters (e.g., total, lowand high-density cholesterol, triacylglycerol concentrations, etc.)

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have decreased a bit. Moreover, arterial blood pressure, the anthropometric and body composition, and pulse evaluation indicators of the recipients did not show any significant change (Liutkevicius et al., 2016). Nowadays, there is also an urgent need for valorization of food processing waste or by-products as a source of bioactive compounds for sustainability in the food and agricultural sectors. An approach proposed by Servili et al. (2011) was to recover bioactive phenols from by-products derived during processing of virgin olive oil and to add them to milk-based beverages. According to the researchers, sensory analysis based on triangle and paired comparison tests showed that phenolic compounds at the concentrations of 100 or 200 mg/L were suitable for addition to functional milk beverages. A balanced diet and healthy lifestyle are common values for all consumers globally. Obesity, diabetes, and other health issues related to weight management are now considered as global health problems as their occurrence continue to rise all over the world. Based on the body mass index (BMI), approximately 62% of the adult population is classified as overweight in the United States, and in the last 10 years obesity has increased by 10%–50% in most of the European countries. A primary cause of death is still the heart disease, responsible for 20%–30% of deaths throughout the world, and cancer, osteoporosis, and arthritis are other highly common diseases. Although genetical tendency is considered as an important factor in the incidence of the above-mentioned diseases, in general most of them are considered to be preventable or can be minimized by a healthy diet and a healthier lifestyle. Hence, people are trying to optimize their diet in order to increase health-ensuring capabilities thereof via nutritional supplements or by consuming food and beverages that have been reformulated to contain health-improving factors (Wildman and Kelly, 2007). Japan, Europe, and United States have been leading in the innovation and acquisition of intellectual property in the field of functional foods and bioactive ingredients (Granato et al., 2010). Dairy industries have created a huge market share in functional beverage category with a diversity of added-value milk beverages such as low calorie and reduced-fat products and those fortified with prebiotics, omega-3 fatty acids, plant sterol, many other bioactive compounds together with fermented milkbased beverages (Khurana and Kanawjia, 2007; Corbo et al., 2014). Foremost among them, with their proven health benefits, milk and fermented milks, including kefir, koumiss, and yogurt beverages, have been consumed for millennia in regions from the Central Asia to the Middle East, and from the Caucasus and Asia Minor to Eastern Europe. Besides these traditional products, the development of novel probiotic, symbiotic dairy beverages, and hybrid dairy products like fruit-yogurt beverages are in progress due to the increasing demand

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   27

for such functional products (Khurana and Kanawjia, 2007; Granato et al., 2010; Kandylis et al., 2016). Probiotics have been experiencing strong growth in functional dairy drinks so far. Within Europe, the sales report states that Spain, Germany, and the United Kingdom are the largest markets of probiotic yogurt drinks worth US$700 million, US$515 million, and US$500 million, respectively (Searby, 2012). Allgeyer et al. (2010) assessed the sensory profile of drinkable yogurts produced by prebiotics and probiotics. According to results, the significant attributes identified in the yogurt drinks were clover honey aroma, buttermilk aroma, butter aroma, sweetness, sourness, chalky mouthfeel, and viscosity. To increase the acceptance of fermented milks, whey-based beverages and yogurts, the industry should focus on increasing the flavor acceptance of these products, as the flavor is directly related to the overall acceptance revealed by Farah et al. (2017) also, recently.

1.4.2  Challenges and Technological Opportunities for Production of Functional Milk Beverages Although milk and fermented milk products are the generally favored vehicles for the delivery of bioactive ingredients, during inclusion of bioactive ingredients into milk beverages, potentially certain challenges are faced by suppliers. Most of these challenges relates to the sensory attributes and physical stability problems that may render the final product unpleasant for consumers (Sharma, 2016). Flavor is the most important factor determining the overall acceptability of such foods. As is the case with any food product, the main goal is to develop and provide a product that has an acceptable flavor that is at first characterized by an identifying flavor (e.g., vanilla, chocolate, and strawberry), rapid progress of a balanced and full-bodied flavor, compatible mouthfeel and texture, no off-flavors, and minimized aftertaste. When consumers try a product, it is important to ensure that the first impression should be that of the intended, desirable sensations (Corbo et al., 2014; Cadwallader, 2016). The main purpose of the developer of the product is to deliver consumers functional beverages that not only provide the intended health-promoting benefits but also taste good. During the production of functional milk beverages there are certain flavor challenges faced with different ingredients used in the new formulations due to the inherent off-flavors contained therein. In order to create an effective strategy for the reduction or elimination of the sense of off-flavors, it is essential for the product developers to know the nature of all ingredients and microorganisms used in the development of the new formulation. For instance, glucosinolates and polyphenolics (including resveratrol, quercetin, and fisetin) are commonly used functional ingredients. When they are

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incorporated into various products, they may impart undesirable bitter and mouthfeel characteristics to the new formulation (Gaudette and Pickering, 2013). In addition, possible interactions with other food components, effects of process, and storage conditions on each functional ingredient and technological improvements in the process should be take into account (Corbo et al., 2014; Allgeyer et al., 2010; Esmerino et al., 2017). Kawaii (2014) patented the improving flavor of a fermented milk by employing a lactose degradation step and, further, adding a whey powder to a starting material thereby controlling the balance between the sweetness and sourness of the fermented milk. Texture and mouthfeel characteristics are another sensory attributes of related fermented milk-based beverages. For example, lowfat/fat-free fermented milks and whey-based beverages, because of the low total solid contents, have undesirable textural, rheological, and sensory characteristics in comparison to that of full-fermented milk. Thus, several studies have been performed to improve the sensory attributes of such beverages either by using exopolysaccharide (EPS)-producing starter cultures or by the addition of different types of hydrocolloids (Gallardo-Escamilla et  al., 2007; Lin and Chien, 2007; Yilmaz et al., 2015). From the point of view of consumers, they expect fermented beverages to have certain characteristics of those found in traditional equivalents, visually and in textural properties. Fermented milk-based beverages produced by using probiotic strains of Bifidobacterium spp. and L. acidophilus only are often considered to have poor flavor properties, and lack of texture and s­ tructural ­features (Gallardo-Escamilla et  al., 2007; Patrignani et  al., 2009). When EPS-producing LAB and Bifidobacteria are used in the fermentation of dairy products, they can give technological benefits to end products, like improved texture and reduced syneresis. Besides acting as texture improver, some EPS produced by LAB have shown beneficial impacts on human health (Behare, 2009). Lots of work have been done on isolation of EPS-producing strains of Lactobacillus from a variety of sources, both food (dairy, nondairy) or nonfood sources, recovery and quantification of them with several methods, and determining cultural and environmental factors affecting their production (Lin and Chien, 2007; Behare, 2009; Yilmaz et al., 2015). New and emerging nonthermal technologies could improve the characteristics of functional beverages during their production. Since there is growing attraction toward bioactive functional food ingredients originating from dairy sources, it is desired to preserve lactoperoxidase activity and other valuable heat-labile molecules during preservation processes of dairy products. Relatively low process temperatures and microsecond exposure times of pulsed electric field (PEF) processing or its combination with lower pasteurization temperatures have the potential of obtaining microbial inactivation l­ evels

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in milk that is comparable to conventional thermal pasteurization method, which promote retention of dairy product quality and nutrients (Buckow et al., 2014). The high-pressure homogenization (HPH) treatment of milk can potentially differentiate the product in the market for probiotic fermented milks, especially with respect to texture parameters (Patrignani et al., 2009, 2017). Patrignani et al. (2017) reported that an application of 50 MPa for five passes resulted in a high yield of entrapped Lactobacilli viable cells. The same researchers highlighted that the obtained microcapsules were also functional in terms of maintaining high probiotic viability specifically for Lactobacillus paracasei in the fermented milk during refrigerated storage, and even till the end of the storage. Moreover, encapsulation of probiotic strains influenced texture parameters of fermented products by modulating the release of EPSs. Microencapsulation and nanotechnology have evolved as two advanced technologies with huge potential for supplementation of bioactive and nutritional ingredients into milk and dairy products. These technologies are relatively new to the dairy industry and has already found several applications, such as encapsulation of omega-3 polyunsaturated fatty acids, nano/chitosan, nano/peanut sprout, lactase, iron, vitamin C, probiotic bacteria, nanoginseng, and many more (Kwak et al., 2014). Since the market demand for functional/value-added milk and milk-based beverages are anticipated to get extremely high in the near future, such products have been attracting greater consumer interest. Hereby, consumer tendencies, behaviors, and the factors influencing their purchasing decision related to functional/added-value milk beverages, challenges, and the novel technological developments were attempted to bring to the attention of people working for producing such products, marketing, and doing researches on them. There are several challenges that need to be dealt with, for example, trying to isolate new strains of probiotics from different sources which potentially brings up possibilities for the selecting and maintaining the viability of fermenting microorganisms during production and storage, development of products having new functionalities, investigate effects of compositional and environmental fermentation parameters on fermentation process, deciding the packaging design, and aiming to retain stability of the product during the shelf life. Also, further genetic engineering studies and new technological possibilities are necessary, for example, to reveal the contribution level of each microorganism in the final product composition and to enhance the concentrations of preferred compounds produced by them in the final fermented products or developing bacteriocin-producing starter cultures for prolonged shelf life. The guarantee of well-being and good health offered by such beverages are the most significant factors affecting consumers’ buying decision of foods. Therefore, in-depth clinical studies are

30  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

necessary to understand the dynamics of functional ingredients after the ingestion of such products and their interaction within the body. Nowadays, movement toward the benefits of food on health and on social and environmental aspects has motivated the food industry toward development and application of novel technologies and market strategies for production of functional milk-based beverages with improved properties. Milk and milk-based fermented beverages seem to be the driving force of future functional food sector, which looks more promising than ever.

1.5 Conclusion The functional food comprises many factors such as nutraceuticals, human health, and food awareness. The main goal of the production or development of functional foods is to meet the modern consumer’s demand for healthy and wellness lifestyles. Milk-based beverages seem to be an opportunistic way to achieve this purpose in the functional food market from commercial perspective. Today, many types of milk-based beverages which have several functional properties are introduced to consumers by food manufacturers even though different kinds of milk-based beverages with different formulations are on the marketplace. High-protein milk drinks, fermented milks formulated with plant phytosterols/stanols, and whey beverages with fruit or vegetable juice are the most striking examples. But, it should not be forgotten that the health-promoting claims of milk-based beverages present in the market must be verified with deep clinical studies to clarify functional ingredients effects on the human body by metabolomics approach. This would benefit the consumers as well as the producers vitally. From technological point of view, the development of food processing technologies will provide novel milk-based beverages with different flavors and textural characteristics in the near future.

References Ahmed, Z., Wang, Y., Ahmad, A., Khan, S.T., Nisa, M., Ahmad, H., Afreen, A., 2013. Kefir and health: a contemporary perspective. Crit. Rev. Food Sci. Nutr. 53, 422–434. Akin, Z., Ozcan, T., 2017. Functional properties of fermented milk produced with plant proteins. LWT Food Sci. Technol. 86, 25–30. Akuzawa, R., Surono, I.S., 2002. Fermented milks of Asia. In: Roginski, H. (Ed.), Encyclopedia of Dairy Sciences. Elsevier, Oxford. Alemany-Costa, L., González-Larena, M., García-Llatas, G., Alegría, A., Barberá, R., Sánchez-Siles, L.M., Lagarda, M.J., 2012. Sterol stability in functional fruit beverages enriched with different plant sterol sources. Food Res. Int. 48, 265–270. Allen, L., De Benoist, B., Dary, O., Hurrell, R., 2006. Guidelines on Food Fortification With Micronutrients. World Health Organization and Food and Agriculture Organization of the United Nations, France.

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   31

Allgeyer, L.C., Miller, M.J., Lee, S.Y., 2010. Sensory and microbiological quality of yogurt drinks with prebiotics and probiotics. J. Dairy Sci. 93, 4471–4479. Anonymous, 2009. Phytosterol/Stanol Enriched Foods. Heart Foundation, Australia. Anonymous, 2011. Who/Fao Codex Standard for Fermented Milks. Rome-Italy. Anonymous, 2015a. Dairy Free Beverages Expand the Milk Aisle. [Online]. Available: http://www.ift.org/newsroom/news-releases/2015/february/18/dairy-free-beverages-expand-the-milk-aisle.aspx. (Accessed 8 September, 2017). Anonymous, 2015b. Yogurts, Dairy Beverages Lead Protein New Product Development. [Online]. Available: http://www.ift.org/newsroom/news-releases/2015/february/18/ dairy-free-beverages-expand-the-milk-aisle.aspx. (Accessed 15 September, 2017). Anonymous, 2016. Functional foods and beverages in Japan. In: Agriculture and AgriFood Canada Market Acces Secretariat Global Analysis Report. Anonymous, 2017a. Flavoured Milk. [Online]. Available: http://dairy-technology.blogspot.com.tr/2014/01/flavoured-milk.html. (Accessed 22 September, 2017). Anonymous, 2017b. Production of Flavored Milk Drinks. [Online]. Available: http:// www.silverson.com/us/resource-library/application-reports/production-of-flavored-milk-drinks/. (Accessed 15 June, 2017). Anonymous, 2017c. Flavoured Milk—A Growing Demand. [Online]. Available: https:// www.tetrapak.com/findbyfood/dairy/flavoured-milk. (Accessed 15 June, 2017). Anonymous, 2017d. Manufacture of Smoothies. [Online]. Available: http://www.silverson.com/us/resource-library/application-reports/manufacture-of-smoothies. (Accessed 15 June, 2017). Anonymous, 2017e. Help Build a Brighter Future, One Spoon at a Time-USDA Guidelines. [Online]. Available: http://www.dannonfoodservice.com/wp-content/ uploads/Dan150157-Usda-Guidelines-QA_R7HR.pdf. (Accessed 22 September, 2017). Anonymous, 2017f. Instant Milkshake. [Online]. Available: http://www.faravelli.it/admin/filecaricati/file_ab7353dac00a1ccea0637d59d8ca4e26.pdf. (Accessed 18 July, 2017). Anonymous, 2017g. Fortification Basics. [Online]. Available: http://www.dsm.com/content/dam/dsm/nip/en_US/documents/milk.pdf. (Accessed 22 November, 2017). Anonymous, 2017h. Forecast Volume of Whey Powder Produced in the European Union (EU 28) From 2015 to 2026. [Online]. Available: https://www.statista.com/statistics/547019/whey-powder-production-volume-european-union-28/. (Accessed 15 August, 2017). Arbuckle, S., 1969. Process of Preparing a Thixotropic Milk Shake. US 3479187A. Argan, E., Güneşer, O., Karagül-Yüceer, Y., Kırca-Toklucu, A., 2015. Production of whey powder added fruit beverages ans some quality characteristics (in Turkish). Turk. J. Agric. Food Sci. Technol. 3, 651–658. Arora, S., Shree, S., Gupta, C., 2014. Fortification of milk and milk products for value addition. In: Dairy Year Book, pp. 105–109. Arts, M.J.T.J., Haenen, G.R.M.M., Voss, H.P., Bast, A., 2001. Masking of antioxidant capacity by the interaction of flavonoids with protein. Food Chem. Toxicol. 39, 787–791. Bag, A., Chattopadhyay, R.R., 2018. Evaluation of antioxidant potential of essential oils of some commonly used Indian spices in in vitro models and in food supplements enriched with omega-6 and omega-3 fatty acids. Environ. Sci. Pollut. Res. 25, 388–398. Balaswamy, K., Prabhakara Rao, P., Nagender, A., Narsing Rao, G., Sathiya Mala, K., Jyothirmayi, T., Math, R., Satyanarayana, A., 2013. Development of smoothies from selected fruit pulps/juices. Int. Food Res. J. 20, 1181–1185. Barth, R., 2001. From the orginal idea of a products to the introduction in to the market and finally to the creation of a real brand name. In: Anonymous (Ed.), The Importance of Whey and Whey Components in Food and Nutrition. Behr’s Verlag, Hamburg, Germany, pp. 147–156.

32  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Baumgartner, S., Ras, R., Trautwein, E., Mensink, R.P., Plat, J., 2017. Plasma fat-­soluble vitamin and carotenoid concentrations after plant sterol and plant stanol ester consumption—a meta-analysis of randomized controlled trials. Eur. J. Nutr. 56, 909–923. Behare, P., 2009. Exopolysaccharides of lactic acid bacteria—a review. J. Food Sci. Technol. 46, 1–11. Beheshtipour, H., Mortazavian, A.M., Mohammadi, R., Sohrabvandi, S., KhosraviDarani, K., 2013. Supplementation of Spirulina platensis and Chlorella vulgaris algae into probiotic fermented milks. Compr. Rev. Food Sci. Food Saf. 12, 144–154. Bogue, J., Troy, A.J., 2016. Functional beverages: market trends and market-oriented new product design. In: Shahidi, F., Alasalvar, C. (Eds.), Handbook of Functional Beverages and Human Health. CRC Press, Baco Raton. Boroski, M., Giroux, H.J., Sabik, H., Petit, H.V., Visentainer, J.V., Matumoto-Pintro, P.T., Britten, M., 2012. Use of oregano extract and oregano essential oil as antioxidants in functional dairy beverage formulations. LWT Food Sci. Technol. 47, 167–174. Bozin, B., Mimica-Dukic, N., Samojlik, I., Jovin, E., 2007. Antimicrobial and antioxidant properties of rosemary and sage (Rosmarinus officinalis L. and Salvia officinalis L., Lamiaceae) essential oils. J. Agric. Food Chem. 55, 7879–7885. Brogie, M., 2017. 5 Success-Driving Beverage Industry Trends of 2017. [Online]. Available https://www.repsly.com/blog/consumer-goods/beverage-industry-trendsof-2017. (Accessed 24 September, 2017). Buckow, R., Chandry, P.S., Ng, S.Y., Mcauley, C.M., Swanson, B.G., 2014. Opportunities and challenges in pulsed electric field processing of dairy products. Int. Dairy J. 34, 199–212. Cadwallader, K., 2016. Flavor challenges in functional beverages. In: Shahidi, F., Alasalvar, C. (Eds.), Handbook of Functional Beverages and Human Health. CRC Press, Boca Raton. Castro, W.F., Cruz, A.G., Bisinotto, M.S., Guerreiro, L.M.R., Faria, J.A.F., Bolini, H.M.A., Cunha, R.L., Deliza, R., 2013. Development of probiotic dairy beverages: rheological properties and application of mathematical models in sensory evaluation. J. Dairy Sci. 96, 16–25. Chandan, R.C., 2013. History and consumption trends. In: Manufacturing Yogurt and Fermented Milks. John Wiley & Sons, Inc., Chapel Hill, NC. Chavan, R., Shraddha, R., Kumar, A., Nalawade, T., 2015. Whey based beverage: its functionality, formulations, health benefits and applications. J. Food Process. Technol. 6, 1–8. Chen, M., Sun, Q., Giovannucci, E., Mozaffarian, D., Manson, J.E., Willett, W.C., Hu, F. B., 2014. Dairy consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. BMC Med. 12, 215. Chorianopoulos, N., Kalpoutzakis, E., Aligiannis, N., Mitaku, S., Nychas, G.-J., Haroutounian, S., 2005. Essential oils of Satureja, Origanum, and Thymus species: chemical composition and antibacterial activities against foodborne pathogens. J. Agric. Food Chem. 52, 8261–8267. Cilla, A., Alegría, A., De Ancos, B., Sánchez-Moreno, C., Cano, M.P., Plaza, L., Clemente, G., Lagarda, M.J., Barberá, R., 2012. Bioaccessibility of tocopherols, carotenoids, and ascorbic acid from milk- and soy-based fruit beverages: influence of food matrix and processing. J. Agric. Food Chem. 60, 7282–7290. Corbo, M.R., Bevilacqua, A., Petruzzi, L., Casanova, F.P., Sinigaglia, M., 2014. Functional beverages: the emerging side of functional foods. Compr. Rev. Food Sci. Food Saf. 13, 1192–1206. Davidson, G.P., Daniels, E., Nunan, H., Moore, A.G., Whyte, P.B.D., Franklin, K., Mccloud, P.I., Moore, D.J., 1989. Passive immunisation of children with bovine colostrum containing antibodies to human rotavirus. Lancet 334, 709–712. Djurić, M., Carić, M., Milanović, S., Tekić, M., Panić, M., 2004. Development of wheybased beverages. Eur. Food Res. Technol. 219, 321–328.

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   33

Dupas, C.J., Marsset-Baglieri, A.C., Ordonaud, C.S., Ducept, F.M.G., Maillard, M.-N., 2006. Coffee antioxidant properties: effects of milk addition and processing conditions. J. Food Sci. 71, S253–S258. Esmerino, E.A., Ferraz, J.P., Filho, E.R.T., Pinto, L.P.F., Freitas, M.Q., Cruz, A.G., Bolini, H.M.A., 2017. Consumers’ perceptions toward 3 different fermented dairy products: insights from focus groups, word association, and projective mapping. J. Dairy Sci. 100, 8849–8860. FAO, 2017. Food Fortification: Technology and Quality Control. [Online]. Available: http:// www.fao.org/docrep/W2840E/w2840e03.htm. (Accessed 22 November, 2017). Farah, J.S., Araujo, C.B., Melo, L., 2017. Analysis of yoghurts’, whey-based beverages’ and fermented milks’ labels and differences on their sensory profiles and acceptance. Int. Dairy J. 68, 17–22. Farnworth, R.E., 2005. Kefir a complex probiotic. In: Gibson, G.R. (Ed.), Food Science and Technology Bulletin: Functional Food. IFIS Publishing, Reading, UK. Fiorda, F.A., DE Melo Pereira, G.V., Thomaz-Soccol, V., Medeiros, A.P., Rakshit, S.K., Soccol, C.R., 2016. Development of kefir-based probiotic beverages with DNA protection and antioxidant activities using soybean hydrolyzed extract, colostrum and honey. LWT Food Sci. Technol. 68, 690–697. Fluegel, S.M., Shultz, T.D., Powers, J.R., Clark, S., Barbosa-Leiker, C., Wright, B.R., Freson, T.S., Fluegel, H.A., Minch, J.D., Schwarzkopf, L.K., Miller, A.J., Di Filippo, M.M., 2010. Whey beverages decrease blood pressure in prehypertensive and hypertensive young men and women. Int. Dairy J. 20, 753–760. Freire, F.C., Adorno, M.A.T., Sakamoto, I.K., Antoniassi, R., Chaves, A.C.S.D., Dos Santos, K.M.O., Sivieri, K., 2017. Impact of multi-functional fermented goat milk beverage on gut microbiota in a dynamic colon model. Food Res. Int. 99, 315–327. Gad, A., Emam, W., Mohamed, G., Ahmed, F., 2013. Utilization whey in production of functional healthy beverage “whey-mango beverages”. Am. J. Food Technol. 8, 133–148. Gallardo-Escamilla, F.J., Kelly, A.L., Delahunty, C.M., 2007. Mouthfeel and flavour of fermented whey with added hydrocolloids. Int. Dairy J. 17, 308–315. Garcia-Llatas, G., Cilla, A., Alegría, A., Lagarda, M.J., 2015. Bioavailability of plant ­sterol-enriched milk-based fruit beverages: in  vivo and in  vitro studies. J. Funct. Foods 14, 44–50. Gaudette, N.J., Pickering, G.J., 2013. Modifying bitterness in functional food systems. Crit. Rev. Food Sci. Nutr. 53, 464–481. Granato, D., Branco, G.F., Cruz, A.G., Faria, J.D.A.F., Shah, N.P., 2010. Probiotic dairy products as functional foods. Compr. Rev. Food Sci. Food Saf. 9, 455–470. Greenwalth, C.J., Steinkraus, K.H., Ledford, R.A., 2000. Kombucha, the fermented tea: microbiology, composition, and claimed health effects. J. Food Prot. 63, 976–981. Guo, H.Y., Pang, K., Zhang, X.Y., Zhao, L., Chen, S.W., Dong, M.L., Ren, F.Z., 2007. Composition, physiochemical properties, nitrogen fraction distribution, and amino acid profile of donkey milk. J. Dairy Sci. 90, 1635–1643. Gupta, S., Kulkarni, S., 1983. Recent technological advances in milk-based beverages. Indian Dairyman 35, 593–602. Güzel-Seydim, Z.B., Seydim, A.C., Greene, A.K., Bodine, A.B., 2000. Determination of organic acids and volatile flavor substances in kefir during fermentation. J. Food Compos. Anal. 13, 35–43. Guzel-Seydim, Z.B., Seydim, A.C., Greene, A.K., Taş, T., 2006. Determination of antimutagenic properties of acetone extracted fermented milks and changes in their total fatty acid profiles including conjugated linoleic acids. Int. J. Dairy Technol. 59, 209–215. Guzel-Seydim, Z., Kök Taş, T., Greene, A.K., 2010. Kefir and Koumiss: microbiology and technology. In: Yildiz, F. (Ed.), Development and Manufacture of Yoğurt and Other Functional Dairy Products. CRC Press, Boca Raton.

34  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Hafeez, Z., Cakir-Kiefer, C., Roux, E., Perrin, C., Miclo, L., Dary-Mourot, A., 2014. Strategies of producing bioactive peptides from milk proteins to functionalize fermented milk products. Food Res. Int. 63, 71–80. He, Z., Yuan, B., Zeng, M., Tao, G., Chen, J., 2015. Effect of simulated processing on the antioxidant capacity and in vitro protein digestion of fruit juice-milk beverage model systems. Food Chem. 175, 457–464. Hernandez, E.M., 2014. Issues in fortification and analysis of omega-3 fatty acids in foods. Lipid Technol. 26, 103–106. Hertrampf, E., 2002. Iron fortification in the Americas. Nutr. Rev. 60, S22–S25. Hilliam, M., 2000. Functional food—how Big Is the market? In: The World of Food Ingredients. vol. 12, pp. 50–52. Jacek, R., Beata, F., Robert, O., Maciej, B., Anna, G.-B., 2017. The use of plant sterols and Stanols as lipid-lowering agents in cardiovascular disease. Curr. Pharm. Des. 23, 2488–2495. Janeth Rodríguez-Roque, M., Rojas-Graü, M., Elez-Martinez, P., Martin-Belloso, O., 2013. Changes in vitamin C, phenolic, and carotenoid profiles throughout in  vitro gastrointestinal digestion of a blended fruit juice. J. Agric. Food Chem. 61, 1859–1867. Jelen, P., 2009. Whey-based functional beverages. In: Paquin, P. (Ed.), Functional and Speciality Beverage Technology. Woodhead Publishing, Boca Raton. Jeličić, I., Barukčić, I., Božanić, R., Tratnik, L., 2008. Whey-based beverages-a new generation of diary products. Mljekarstvo 58, 257–274. Jiménez-Flores, R., Higuera-Ciapara, I., Pouliot, Y., 2009. Beverages based on milk fat globule membrane (Mfgm) and other novel concepts for dairy-based functional beverages. In: Paquin, P. (Ed.), Functional and Speciality Beverage Technology. Woodhead Publishing, Cambridge. Kanareikin, V.I., 2016. Development of koumiss product for preventive purpose. Oil Gas Bus. J., 255–278. Kandylis, P., Pissaridi, K., Bekatorou, A., Kanellaki, M., Koutinas, A.A., 2016. Dairy and non-dairy probiotic beverages. Curr. Opin. Food Sci. 7, 58–63. Kanekanian, A., 2014. The health benefits of bioactive compounds from milk and dairy products. In: Kanekanian, A. (Ed.), Milk and Dairy Products as Functional Foods. John Wiley & Sons, Ltd, Oxford. Kawaii, Y., 2014. Fermented Milk With Improved Flavor and Method for Producing Same. US Patent Application Publication, EP2682000A1. Kawasaki, Y., Isoda, H., Tanimoto, M., Dosako, S.I., Idota, T., Ahiko, K., 1992. Inhibition by lactoferrin and κ-casein glycomacropeptide of binding of cholera toxin to its receptor. Biosci. Biotechnol. Biochem. 56, 195–198. Kelly, P., Woonton, B.W., Smithers, G.W., 2009. Improving the sensory quality, shelf-life and functionality of milk. In: Paquin, P. (Ed.), Functional and Speciality Beverage Technology. Woodhead Publishing, Boca Raton. Keogh, J.B., Mcinerney, J., Clifton, P.M., 2007. The effect of milk protein on the bioavailability of cocoa polyphenols. J. Food Sci. 72, S230–S233. Khurana, H.K., Kanawjia, S.K., 2007. Recent trends in development of fermented milks. Curr. Nutr. Food Sci. 3, 91–108. Kim, M.K., Lopetcharat, K., Drake, M.A., 2013. Influence of packaging information on consumer liking of chocolate milk. J. Dairy Sci. 96, 4843–4856. Kinik, O., Akaln, S., Gonc, S., 2000. A research on koumiss production and its properties. J. Food 25, 379–384. Kocak, C., Avsar, Y., 2009. Ayran: microbiology and technology. In: Yildiz, F. (Ed.), Development and Manufacture of Yogurt and Other Functional Dairy Products. CRC Press, London. Koffi, E., Shewfelt, R., Wicker, L., 2005. Storage stability and sensory analysis of Uhtprocessed whey-banana beverages. J. Food Qual. 28, 386–401.

Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES   35

Królczyk Jolanta, B., Dawidziuk, T., Janiszewska-Turak, E., Sołowiej, B., 2016. Use of whey and whey preparations in the food industry—a review. Pol. J. Food Nutr. Sci. 66, 157–165. Kussendrager, K.D., van Hooijdonk, A.C.M., 2007. Lactoperoxidase: physico-chemical properties, occurrence, mechanism of action and applications. Br. J. Nutr. 84, 19–25. Kwak, H.-S., Mijan, M.A., Ganesan, P., 2014. Application of nanomaterials, nano- and microencapsulation to milk and dairy products. In: Nano- and Microencapsulation for Foods. John Wiley & Sons, Ltd, West Sussex. Legarová, V., Kouřimská, L., 2010. Sensory quality evaluation of whey-based beverages. Mljekarstvo 60, 280–287. Leite, A.M.D.O., Miguel, M.A.L., Peixoto, R.S., Rosado, A.S., Silva, J.T., Paschoalin, V.M.F., 2013. Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage. Braz. J. Microbiol. 44, 341–349. Lenkov, N., 1969. Beverage “Bodrost”. Moloch. Prom. 30, 25–28. Li, X.E., Lopetcharat, K., Drake, M., 2014. Extrinsic attributes that influence parents’ purchase of chocolate milk for their children. J. Food Sci. 79, S1407–S1415. Lin, T.Y., Chien, M.F.C., 2007. Exopolysaccharides production as affected by lactic acid bacteria and fermentation time. Food Chem. 100, 1419–1423. Liutkevicius, A., Speiciene, V., Alencikiene, G., Aldona, M., Narkevicius, R., Kaminskas, A.J.J.A., Vitkus, D., Jablonskiene, V., Sekmokiene, D., 2016. Fermented ­buttermilk-based beverage: impact on young volunteers’ health parameters. Czech J. Food Sci. 34, 143–148. Lv, J.-P., Wang, L.-M., 2009. Bioactive components in kefir and koumiss. In: Young, W. (Ed.), Bioactive Components in Milk and Dairy Products. Wiley-Blackwell, Singapore. Magalhães, K.T., Pereira, M.A., Nicolau, A., Dragone, G., Domingues, L., Teixeira, J.A., De Almeida Silva, J.B., Schwan, R.F., 2010. Production of fermented cheese whey-based beverage using kefir grains as starter culture: evaluation of morphological and microbial variations. Bioresour. Technol. 101, 8843–8850. Magalhães, K.T., Dragone, G., De Melo Pereira, G.V., Oliveira, J.M., Domingues, L., Teixeira, J.A., e Silva, J.B.A., Schwan, R.F., 2011a. Comparative study of the biochemical changes and volatile compound formations during the production of novel whey-based kefir beverages and traditional milk kefir. Food Chem. 126, 249–253. Magalhães, K.T., Pereira, G.V.D.M., Campos, C.R., Dragone, G., Schwan, R.F., 2011b. Brazilian kefir: structure, microbial communities and chemical composition. Braz. J. Microbiol. 42, 693–702. Malbaša, R.V., Milanović, S.D., Lončar, E.S., Djurić, M.S., Carić, M.D., Iličić, M.D., Kolarov, L., 2009. Milk-based beverages obtained by Kombucha application. Food Chem. 112, 178–184. Marsh, A.J., Hill, C., Ross, R.P., Cotter, P.D., 2014. Fermented beverages with health-­ promoting potential: past and future perspectives. Trends Food Sci. Technol. 38, 113–124. McCarthy, K.S., Parker, M., Ameerally, A., Drake, S.L., Drake, M.A., 2017. Drivers of choice for fluid milk versus plant-based alternatives: what are consumer perceptions of fluid milk? J. Dairy Sci. 100, 6125–6138. Mehta, D., Kumar, M.H.S., Sabikhi, L., 2017. Development of high protein, high fiber smoothie as a grab-and-go breakfast option using response surface methodology. J. Food Sci. Technol. 54, 3859–3866. Mellema, M., Bot, A., 2009. Milk-based functional beverages. In: Paquin, P. (Ed.), Functional and Speciality Beverage Technology. Woodhead Publishing, Boca Raton. Mulder, A.M., Connellan, P.A., Oliver, C.J., Morris, C.A., Stevenson, L.M., 2008. Bovine lactoferrin supplementation supports immune and antioxidant status in healthy human males. Nutr. Res. 28, 583–589.

36  Chapter 1  ENGINEERING OF MILK-BASED BEVERAGES

Nagarajappa, V., Battula, S.N., 2017. Effect of fortification of milk with omega-3 fatty acids, phytosterols and soluble fibre on the sensory, physicochemical and microbiological properties of milk. J. Sci. Food Agric. 97, 4160–4168. Neffati, M., Marzouk, B., 2008. Changes in essential oil and fatty acid composition in coriander (Coriandrum sativum L.) leaves under saline conditions. Ind. Crop. Prod. 28, 137–142. Nielsen, B., Gürakan, G.C., Ünlü, G., 2014. Kefir: a multifaceted fermented dairy product. Probiotics Antimicrob. Proteins 6, 123–135. Özer, B., 2006. Yogurt Bilimi ve Teknolojisi (In Turkish). Sidaş Medya, İzmir, Turkey. Özer, B.H., Kirmaci, H.A., 2010. Functional milks and dairy beverages. Int. J. Dairy Technol. 63, 1–15. Patrignani, F., Burns, P., Serrazanetti, D., Vinderola, G., Reinheimer, J., Lanciotti, R., Guerzoni, M.E., 2009. Suitability of high pressure-homogenized milk for the production of probiotic fermented milk containing Lactobacillus paracasei and Lactobacillus acidophilus. J. Dairy Res. 76, 74–82. Patrignani, F., Siroli, L., Serrazanetti, D.I., Braschi, G., Betoret, E., Reinheimer, J.A., Lanciotti, R., 2017. Microencapsulation of functional strains by high pressure homogenization for a potential use in fermented milk. Food Res. Int. 97, 250–257. Perna, A., Intaglietta, I., Simonetti, A., Gambacorta, E., 2015. Donkey milk for manufacture of novel functional fermented beverages. J. Food Sci. 80, S1352–S1359. Pescuma, M., Hébert, E.M., Mozzi, F., Font De Valdez, G., 2008. Whey fermentation by thermophilic lactic acid bacteria: evolution of carbohydrates and protein content. Food Microbiol. 25, 442–451. Phillips, D.I., 1997. Iodine, milk, and the elimination of endemic goitre in Britain: the story of an accidental public health triumph. J. Epidemiol. Community Health 51, 391–393. Prado, F.C., Parada, J.L., Pandey, A., Soccol, C.R., 2008. Trends in non-dairy probiotic beverages. Food Res. Int. 41, 111–123. Rodríguez-Roque, M.J., Rojas-Graü, M.A., Elez-Martínez, P., Martín-Belloso, O., 2014. In vitro bioaccessibility of health-related compounds as affected by the formulation of fruit juice- and milk-based beverages. Food Res. Int. 62, 771–778. Russ, W., Meyer-Pittroff, R., 2004. Utilizing waste products from the food production and processing industries. Crit. Rev. Food Sci. Nutr. 44, 57–62. Russ, W., Schnappinger, M., 2007. Waste related to the food industry: a challenge in material loops. In: Oreopoulou, V., Russ, W. (Eds.), Utilization of By-Products and Treatment of Waste in the Food Industry. Springer US, Boston, MA. Sathya, P., Janiya, L., Srinivasan, C.V.M., Sasikumar, S., 2016. Fortification ofmilk and milk products. Int. J. Sci. Environ. Technol. 5, 4125–4129. Schwartz, H., Ollilainen, V., Piironen, V., Lampi, A.-M., 2008. Tocopherol, tocotrienol and plant sterol contents of vegetable oils and industrial fats. J. Food Compos. Anal. 21, 152–161. Searby, L., 2012. Dairy Drinks Driving the European Dairy Market. [Online]. Available: http://www.nutritionaloutlook.com. (Accessed 26 September, 2017). Servili, M., Rizzello, C.G., Taticchi, A., Esposto, S., Urbani, S., Mazzacane, F., Di Maio, I., Selvaggini, R., Gobbetti, M., Di Cagno, R., 2011. Functional milk beverage fortified with phenolic compounds extracted from olive vegetation water, and fermented with functional lactic acid bacteria. Int. J. Food Microbiol. 147, 45–52. Seyhan, E., Yaman, H., Özer, B., 2016. Production of a whey-based functional beverage supplemented with soy isoflavones and phytosterols. Int. J. Dairy Technol. 69, 114–121. Sharma, R., 2016. Dairy beverages. In: Shahidi, F., Alasalvar, C. (Eds.), Handbook of Functional Beverages and Human Health. CRC Press, Boca Raton. Sherkat, F., Shamsi, K., Arjmand, A., 2016. Fermented functional beverages (Kefir, Koumiss, and Ayran). In: Shahidi, F., Alasalvar, C. (Eds.), Handbook of Functional Beverages and Human Health. CRC Press, Boca Raton.

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Sinha, R., Radha, C., Prakash, J., Kaul, P., 2007. Whey protein hydrolysate: functional properties, nutritional quality and utilization in beverage formulation. Food Chem. 101, 1484–1491. Sloan, E., Hutt, C.A., 2012. Beverage trends in 2012 and beyond. AgroFood 23, 8–12. Sorenson, D., Bogue, J., 2009. Consumer-oriented development of functional beverages. In: Paquin, P. (Ed.), Functional and Speciality Beverage Technology. Woodhead Publishing, Boca Raton. Stephan, W., Dichtelmüller, H., Lissner, R., 1990. Antibodies from colostrum in oral immunotherapy. J. Clin. Chem. Clin. Biochem. 28, 19–23. Tadapaneni, R.K., Banaszewski, K., Patazca, E., Edirisinghe, I., Cappozzo, J., Jackson, L., Burton-Freeman, B., 2012. Effect of high-pressure processing and milk on the anthocyanin composition and antioxidant capacity of strawberry-based beverages. J. Agric. Food Chem. 60, 5795–5802. Tripathi, V., Jha, Y.K., 2004. Development of whey beverage with antagonistic characteristics and probiotics. Int. J. Food Prop. 7, 261–272. Turchi, B., Pedonese, F., Torracca, B., Fratini, F., Mancini, S., Galiero, A., Montalbano, B., Cerri, D., Nuvoloni, R., 2017. Lactobacillus plantarum and Streptococcus thermophilus as starter cultures for a donkey milk fermented beverage. Int. J. Food Microbiol. 256, 54–61. Uruakpa, F.O., Ismond, M.A.H., Akobundu, E.N.T., 2002. Colostrum and its benefits: a review. Nutr. Res. 22, 755–767. Vartanian, L.R., Schwartz, M.B., Brownell, K.D., 2007. Effects of soft drink consumption on nutrition and health: a systematic review and meta-analysis. Am. J. Public Health 97, 667–675. Wang, J., Chen, X., Liu, W., Yang, M., Airidengcaicike, Zhang, H., 2008. Identification of Lactobacillus from koumiss by conventional and molecular methods. Eur. Food Res. Technol. 227, 1555–1561. Watson, B., 1968. Sterilized Milkshake and the Process for Making Same. US 3385714A. Webb, B.H., 1938. Utilization of whey in foods. J. Food Sci. 3, 233–281. Wendorff, 2008. Uses of Whey in the Farmstead Setting. Wisconsin Department of Agriculture, Trade, and Consumer Protection, University of Wisconsin, Wisconsin. White, C.H., 2013. Cultured buttermilk. In: Manufacturing Yogurt and Fermented Milks. John Wiley & Sons Inc., Chapel Hill, NC. Wildman, R., Kelly, M., 2007. Nutraceuticals and functional foods. In: Wildman, R. (Ed.), Handbook of Nutraceuticals and Functional Foods. CRC Press Taylor& Francis Group, Boca Raton. Yanes, M., Durán, L., Costell, E., 2002. Effect of hydrocolloid type and concentration on flow behaviour and sensory properties of milk beverages model systems. Food Hydrocoll. 16, 605–611. Yaygin, H. 1992. Kımız ve Özellikleri (In Turkish), Antalya, Yeni Matbaa. Yerlikaya, O., 2014. Starter cultures used in probiotic dairy product preparation and popular probiotic dairy drinks. Food Sci. Technol. 34, 221–229. Yildiz, F., 2010. Overview of yogurt and other fermented dairy products. In: Yildiz, F. (Ed.), Development and Manufacture of Yogurt and Other Functional Dairy Products. CRC Press, London. Yilmaz, M.T., Dertli, E., Toker, O.S., Tatlisu, N.B., Sagdic, O., Arici, M., 2015. Effect of in situ exopolysaccharide production on physicochemical, rheological, sensory, and microstructural properties of the yogurt drink ayran: an optimization study based on fermentation kinetics. J. Dairy Sci. 98, 1604–1624. Zall, R.R., 2004. Managing Food Industry Waste: Common Sense Methods for Food Processors. Blackwell Publishing, Oxford. Zulueta, A., Esteve, M.J., Frígola, A., 2009. Orac and Teac assays comparison to measure the antioxidant capacity of food products. Food Chem. 114, 310–316.

ENGINEERING TOOLS IN MILK-BASED BEVERAGES

2

Yogesh Khetra, Latha Sabikhi Dairy Technology Division, National Dairy Research Institute, Karnal, India

2.1 Introduction Milk has been consumed in one form or other since ages. The limited shelf life of raw milk led the consumers to look for and prepare longer shelf life milk products. Gradually milk and milk products have become a part of the normal diet of consumers all over the world. Milk products can be classified into several categories such as liquid market milk, flavored milk, ice cream and frozen desserts, fermented products (yogurt, dahi, cheese, etc.), concentrated and dried products, and many more. Most of the market segments of dairy products are well established and find a place of prominence in consumer’s food basket. Among these, the segment involving milk-based beverages is such a group, which is still developing and growing. Beverage market is the most rapidly growing market among various food sectors. By 2017, the global market for beverages will be worth approximately US$1347 billion (Bogue and Troy, 2016). However, majority of the market share is held by soft drink industries. The recent trend has been to shift towards healthier options and therefore, industries are searching for innovations to develop new products providing convenience, refreshment, and wellness. Milk-based beverages are considered the most preferred choice for replacement of soft aerated drinks in the market. The global market for milk-based beverages is approximately 100 billion Euros in terms of annual retail sales value. This equals the size of the global liquid milk market (http://www.arlafoods.co.uk, 2016). The market is growing by leap and bounds worldwide, owing to factors such as increased consumer awareness, changing lifestyle, technological advancements, increasing incidences of lifestyle diseases, among others. Leading dairy and food industries like Arla Foods, Nestlè, and Coca-Cola are targeting the milk-based beverage market for consumers of varied demographics to tap the growing market and earn revenues. Milk-based Beverages. https://doi.org/10.1016/B978-0-12-815504-2.00002-5 © 2019 Elsevier Inc. All rights reserved.

39

40  Chapter 2  Engineering Tools in Milk-Based Beverages

A report by the Tata Strategic Group says that the dairy beverage market in India is one of the fastest growing segments in beverage industry (Gupta and Narasimhan, 2016). Growth in this segment can further be accelerated by launching new need-based products, consequent to continuous research and development efforts of food and dairy researchers. Moreover, in India, a large part of the milk production and processing is unorganized, thus indicating the huge potential for industries to leverage upon. Organized dairy-based beverages form a market size of approximately US$196.7 million, which is growing at an annual rate of 30%. It is one of the fastest growing beverage segments in the Indian market today and is likely to become a billion-­ dollar market by 2021, with the current pace of growth. The most important categories of milk-based beverages consist of flavored milk, fermented milk drinks, whey drinks, and milk-fruit drinks. However, functional dairy drinks including high-protein milk beverages, low-fat and low-sugar drinks, and probiotic and prebiotic drinks are becoming popular globally and are being sought after more and more by consumers. There are also significant opportunities for functional beverages in the world’s emerging markets, such as in China, Brazil, Asia Pacific, and Latin America. Industries have the potential of tapping these markets by studying the demographics of the local populace and understanding the trends. Thus, companies can differentiate their product with that of the competitors by continuous efforts in research and development of innovative functional beverages. The global retail value of functional beverages was reported to be US$274 billion in 2011, which represented approximately, 44% of the retail value sales of nonalcoholic beverages. It has also been reported that growth in the functional beverages had outperformed the established market of soft beverages during the period 2012–16. Global market trends have also indicated a decline in the market of low calorie beverages, while the demand for beverages addressing specific health conditions has increased (Bogue and Troy, 2016). In India, functional beverages market is US$300 million and is the fastest growing market. Similarly, milk-based sports and energy drinks are being launched globally in the past few years.

2.2  Milk-Based Beverages Milk beverages are essentially prepared using two broad strategies, the first, keeping the native form of milk stable and prepare beverages and the second, by destabilizing the native form and playing with the structure with or without the addition some exogenous stabilizing agents. Flavored milks belong to the category wherein the native form

Chapter 2  Engineering Tools in Milk-Based Beverages    41

of milk is retained and the milk is flavored with external flavoring components and colors are added. The resultant mix is heat treated (sterilized, pasteurized, etc.) and packed in attractive packaging and sold in the market. In contrast, the other category of milk-based beverages are prepared by destabilizing the native stable form of milk, particularly milk proteins, and forming a gel. Another category of milk-based beverages is acidified milk beverages, wherein the native stable form of milk constituents is preserved by principles employing protein-­ protein or protein-polysaccharide interactions. With the advances in beverage industry, functional drinks have become extremely popular and the demand for varieties is on the rise. These include low calorie drinks (low fat and low sugar), probiotic drinks, prebiotic drinks, and drinks carrying some functional ingredients such as herbs, omega 3 fatty acids, vitamins, and minerals. Techniques such as microencapsulation, nanoencapsulation, etc. have been employed in preparation of such novel drinks with the aim to protect the active functional ingredients against environmental stress and to modulate the release of the ingredient at its target site of action. Formulation of all these beverages involves structural modifications to achieve the targeted objective of increasing product quality, protecting and increasing the stability of milk constituents, and protecting functional ingredients from external environment. As all these modifications impact the product quality in different ways, it is necessary that the manufacturer has a thorough understanding of these reactions. For ease of explanation, milk-based beverages are classified and discussed in this chapter under Sections  2.6–2.8. The native structural characteristics of milk and the basics of structural engineering in foods and their applications are discussed prior to these core sections, to provide the reader a clearer understanding of their role in formulating this class of beverages.

2.3  Structural Aspects of Milk To understand the structural aspects of milk beverages and to modulate it for the desired end use, it is imperative to know about the basic native form of milk constituents and factors that are responsible for the stability of these constituents in milk. Milk is a dynamically balanced mixture of proteins, lipids, carbohydrates, minerals, and water. All these milk components have their own chemistry of stability in milk. Milk carbohydrates are present in soluble form and therefore, represent the easiest chemistry of their stability in water. Contrary to these, milk lipids and proteins have more complex chemistry of stability. Milk lipids are fatty acid esters of glycerol.

42  Chapter 2  Engineering Tools in Milk-Based Beverages

Almost 98% of the milk fat is present in the form of triglycerides and are thus hydrophobic. Despite this, they remain stable in the continuous phase of water as emulsified globules owing to the presence of fat globule membrane on the surface of globules. Milk proteins comprise of caseins and whey proteins. Whey proteins, in their native undenatured form, are soluble, and thus remain stable in milk. Stability of casein, however, is complex and needs understanding of its molecular structure and interaction with minerals present in milk. The stability of milk fat and milk proteins is discussed in the following sections.

2.3.1  Milk Fat: Composition, Structure, and Stability The composition and structure of bovine milk fat have been reviewed comprehensively (Morrison, 1970; Jensen and Clark, 1988; Christie, 1995; Jensen and Newberg, 1995; Jensen, 2002; Vanhoutte and Huyghebaert, 2003; Zegarska, 2003; MacGibbon and Taylor, 2006). Milk lipids are largely composed of triacylglycerols and minor amounts of diacylglycerols, monoacylglycerols, free fatty acids, phospholipids, and sterols. Trace amounts of fat-soluble vitamins, β-carotene, and fat-soluble flavoring compounds are also present in the milk lipids (MacGibbon and Taylor, 2006). Glycerides are fatty acid esters of glycerols and depending on the number of fatty acids attached to a molecule of glycerol (Fig.  2.1), these are categorized as triglyceride (all three –OH groups are attached with fatty acids), diglyceride (two –OH groups are attached with fatty acids), and monoglyceride (only one –OH group is attached with fatty acid). Since majority (~98%) of milk fat consists of triacylglycerols, they have a direct influence on properties of milk fat, such as melting characteristics, hydrophobicity, density, and metabolism in human digestive system. Triacylglycerols are complex mixtures depending on the type of fatty acid attached to the hydroxyl groups. These fatty acids may be saturated or unsaturated; short chain, medium chain, or long chain; branched or unbranched; cis or trans, etc. Properties of milk fat depend, essentially on the exact composition. This composition can thus be engineered to deliver the property of significance as per the product’s requirement. CH2-OH

CH2-OH

CH2-OR3

CH-OH

CH-OR2

CH-OR2

CH2-OR1

CH2-OR1

CH2-OR1

Monoglyceride

Diglyceride

Triglyceride

Fig. 2.1  Chemical structure of mono, di, and triacylglycerols.

Chapter 2  Engineering Tools in Milk-Based Beverages    43

Milk is as an oil-in-water emulsion, whose properties have a marked influence on many properties of milk, including mouthfeel and viscosity. Fat exists in the form of emulsified fat globules, whose size range from approximately 0.1 to 20 μm, with a mean of about 3.5 μm. These globules are stabilized by the presence of the milk fat globule membrane (MFGM) over the surface of the globules. MFGM contains 0.5%–1.0% of the total lipids in milk and is composed principally of phospholipids and neutral lipids. Other than these, MFGM also contains some proteins and glycoproteins (Fox and McSweeney, 1998). The most important aspect or contribution of milk fat globule to dairy beverages is the mouthfeel. The presence of milk fat and its unique composition in the beverages provides such a mouthfeel to the product that is not very easy to simulate by using other source of fat (e.g., vegetable fat). This makes engineering either the composition of low-fat dairy beverages or the structure inevitable to provide same mouthfeel as that of full fat dairy beverages. To understand engineering milk fat for mouthfeel, it is imperative to understand the mechanism of sensory perception of milk fat so that the same can be simulated. Oro-sensory perception of fat has been discussed in Section 2.7.

2.3.2  Milk Proteins: Structure and Stability Structure and stability of milk proteins, particularly casein, is complex and has been reviewed extensively (Swaisgood, 1992; de Kruif, 1998; Dalgleish and Corredig, 2012). Milk contains 3%–3.5% protein and about 80% of this casein. The other category of proteins in milk comprises of the whey proteins and are characterized as soluble proteins. Since whey proteins are soluble, their stability is usually not an issue. However, their interaction with casein upon denaturation plays a significant role in many properties of milk products and in wheybased drinks. Casein is present in milk in the form of micelles, which are spherical complexes, with size ranging from 150 to 200 nm (de Kruif, 1998; Dalgleish and Corredig, 2012). These micelles contain 92% protein and 8% inorganic salts, principally calcium phosphate (Swaisgood, 1992). Various models have been postulated to describe the structure of casein micelles. Of these, the coat-core model (Waugh et  al., 1970), submicellar model, and nanocluster model have been widely reviewed (Farrell et al., 2006; Horne, 2006, 2009). Submicellar model postulated by Schmidt (1982) is still the most accepted model to understand the structure of casein micelle (Swaisgood, 1992; Dalgleish and Corredig, 2012). As per this model, casein micelles are composed of a number of subunits termed as submicelles. These subunits or

44  Chapter 2  Engineering Tools in Milk-Based Beverages

submicelles contain α-s and β-casein as the hydrophobic core material of the spherical complex and are surrounded by κ-casein. The hydrophobic part of κ-casein is attached to the core material while the hydrophilic part extends outside the surface. These subunits are then linked together by calcium phosphate to form a micelle (Swaisgood, 1992). Walstra then proposed an extension of this subunit model, in which he incorporated the concept of steric hindrance for explaining the stability of casein micelles (Walstra, 1990). Casein micelles are present in suspended state in milk at its native pH of 6.6–6.8. This is primarily because of steric repulsive interactions between the micelles. These casein micelles are stable under native conditions, i.e., at normal pH of fresh milk but are prone to enzymatic or acidic destabilization (Dalgleish and Corredig, 2012) to produce a coagulum or precipitate, depending on the type of destabilization occurred or carried out. Acidification tends to disturb the native stabilization of casein micelles by reducing the net negative charge, leading to a decrease in the repulsive interactions. This causes the micelles to aggregate and form floccules (Tromp et al., 2004). Most of the fermented dairy products like yogurt, dahi, lassi, etc. are manufactured by in situ acid production and coagulation because of reduced pH. Stirred yogurt or lassi, the most popular among milk-based beverages, are prepared using this acid coagulated gel as the base product.

2.4  Engineering Food Structures to Modulate Product Functionality Diet and health have been known to be associated since ancient times. In recent times, the changing lifestyles have made it necessary that foods contribute toward health beyond the basic nutrition they provide. Increasing awareness and novel technologies are the main driving forces have drawn consumers’ attention toward food as a source of health, in addition to being the source of nutrient supply. The exponential growth of the functional foods market is fueled by product innovation and demand from increasingly health-conscious consumers with higher disposable incomes. According to the Global Industry Analysts, the world market for functional foods and drinks is expected to reach $130 billion by 2015. Functional foods are simply defined as foods that provide health benefits beyond basic nutrition. The National Academy of Sciences has also defined functional foods as “any modified food or food ingredient that may provide a health benefit beyond the traditional nutrients it contains.” These foods form a part of the normal diet, which is slightly modified to confer physiological benefits to the consumers. Modification usually refers to fortification, with ingredients that provide specific or multiple health

Chapter 2  Engineering Tools in Milk-Based Beverages    45

benefits and also alters the native characteristics of the food to the least possible extent. The wide umbrella of functional foods also covers foods from which unhealthy ingredients such as fat and sodium have been removed. Functional ingredients are derived from plant and animal sources. Carotenoids, dietary fibers, isothiocyanates, phenolic acids, polyols (sugar alcohol, sorbitol, etc.), prebiotics (inulin, fructo-­ oligosaccharides, etc.), soy protein, sterols and stanols, organosulfur compounds (e.g., allicin, allylic sulfides), polyphenols, flavonoids, lycopene, catechins, etc. are some of the most common functional ingredients of plant origin. Most common and widely studied functional ingredients of animal origin are omega-3 fatty acids (eicosapentaenoic acid and docohexaenoic acid), conjugated linoleic acid (CLA), bioactive peptides in milk and milk products and in fish and fish products and probiotics. Functional foods are being developed in practically all food categories. Milk and milk products, particularly milk-based beverages are usually the first choice as a vehicle to carry functional ingredients. In addition, with the advances in separation and isolation techniques in the dairy industry, many dairy-based functional ingredients such as bioactive peptides, growth factors, CLA and MFGM substances among others, are being used as functional ingredients in the development of functional foods. Functional foods are claimed to confer physiological benefits such as reduction in the risk of cardiovascular diseases, cancer prevention, antioxidation, maintenance of mental functions, immunomodulation, etc. However, very few have been validated through scientific studies. Guidelines have been developed or are being developed to establish the scientific evidence base needed to validate health claims for functional foods. There has been an increase in protecting the bioactive/functional ingredients from external environmental stresses during processing, storage, and consumption of food. Delivery systems have been developed for targeted release of the bioactives at the desired site of action (Ubbink and Mezzenga, 2006; Patel and Velikov, 2011; Kang et al., 2012; Chen et al., 2013; Ezhilarasi et al., 2013; Fathi et al., 2014; Scholten et al., 2014; Diarrassouba et al., 2017; Liu et al., 2017). Processed foods are usually multicomponent and multipurpose systems. The interaction among their ingredients determines the microstructure of the food. This microstructure eventually decides the physical properties of foods such as texture and stability. Therefore, the interactions can be modulated to engineer structures with tailored-desired properties (Dickinson, 2007, 2017; Lesmes and McClements, 2009; Moschakis and Biliaderis, 2017; Moschakis et  al., 2017). These may be targeted/tailored for effective delivery of ­encapsulated ­functional ingredients, increased stability or controlled

46  Chapter 2  Engineering Tools in Milk-Based Beverages

­digestion of food constituents (Li et  al., 2010; McClements and Li, 2010). Molecular organization of the ingredients’ physical properties, such as charge density, hydrophobicity, molecular size, etc. under different environmental conditions needs to be thoroughly understood for engineering the structures for desired functionalities (Scholten et  al., 2014). Generally, three different types of structural particles can be prepared: protein fibrils, polysaccharide nanocrystals, and ­protein-polysaccharide complexes (Scholten et al., 2014). Protein fibrils have gained much importance in the food industry in the past decade. Protein fibrils are formed by hydrolysis of some proteins such as β-lactoglobulin (β-lg), ovalbumin, bovine serum albumin (BSA), whey protein isolates (WPI), etc. (Veerman et al., 2003; Scholten et al., 2014). Protein fibrils may be categorized as short and stiff or long and flexible (Sagis et  al., 2004). This length and flexibility of the fibrils decide their functionalities (e.g., gelation time, gel strength, etc.). Thus, these properties/characteristics of the fibrils can be modulated to achieve the desired attributes in the products as per the requirement (van der Linden, 2012). Among milk proteins, β-lg and α-lactalbumin (α-la) show fibril formation upon denaturation or hydrolysis (Ipsen et al., 2001; Sagis et al., 2004). Ipsen and Otte (2007) reported better gel strength due to hydrolyzed α-la in the product. Nanocrystal/rods of some biopolymers such as chitin, cellulose, etc. can be formed upon acid hydrolysis (Santana et al., 2011; Younes et al., 2012; Zoppe et al., 2012). These nanocrystals or nanorods can be used as structurant in various food applications wherein the length and the aspect ratio can be altered to vary the functionality of the nanostructures in the product (Scholten et al., 2014). Complexes, particularly of protein and polysaccharides are the most widely studied and used for altering food structure. The interaction of protein and polysaccharides is influenced by several parameters such as charge density, ionic strength, and weight ratio of polymers. These interactions between proteins and polysaccharides are of utmost importance in acidified milk beverages and in low-fat milk beverages.

2.5  Applications of Structural Engineering in Foods Biopolymer composites find several applications in food industry. Essentially, interfacial properties of food emulsions are tailored with the purpose to: (I) stabilize colloids and emulsions against environmental conditions such as pH, heat and ionic strength during processing, and storage of foods;

Chapter 2  Engineering Tools in Milk-Based Beverages    47

(II) control digestion of the ingredient or food component for desirable purposes; and ( III) control or modulate the release of encapsulated functional ingredient. Proteins are prone to instability against environmental stresses of pH, ionic strength, heat, etc. Aggregation of protein molecules takes place and results in formation of aggregates or floccules. Acidified milk beverages are typical examples of such systems, wherein milk proteins (casein) aggregate at or below their isoelectric point. However, polysaccharides can be added to stabilize the system owing to their interactions with proteins at low pH. The mechanisms on instability at low pH and stabilization at low pH in presence of polysaccharides have been detailed in Section 2.6. Active functional ingredients are being incorporated in almost all categories of foods. To make these ingredients stable during processing, storage, digestion, and to increase their bioaccessibility, they are either microencapsulated or nanoencapsulated. It is important that they are released from the emulsion at the appropriate sites of absorption, so that their benefits are properly accrued. The controlled release of active ingredients has been the area of active research in the present decade. Their release essentially depends on the interfacial properties of the coat material in which they are encapsulated. Therefore, the release of active ingredients can be controlled by modulating the properties of interfacial films. With the advances in nanotechnology, many nanoparticles are now being used to control the release of functional ingredients. Similarly, film properties can be altered to control lipid digestion with the purpose to manipulate lipid intake and satiety. Functional milk beverages prepared with such interventions are discussed in Section 2.8.

2.6  Acidified Milk Beverages Acidified milk beverages form one important category of milkbased beverages. Acidified milk beverages or acidified dairy drinks are prepared either by in situ acid production in milk by starter culture, or by direct addition of acidic fruit juices and pulp in milk or in fermented milk. The creation of acidic conditions disturbs the native stable configuration of casein micelles, owing to the disturbance in pH, resulting in flocculation. Casein micelles are stabilized by the protruding chains of κ-casein, which carry negative charge. Thus, there is net negative charge on micelles, which maintains the steric repulsion between the micelles and prevents them from coalescing. However, upon acidification, this negative charge gets neutralized and casein micelles become prone to aggregation. To prevent flocculation and to keep the b ­ everages homogenous, acidified milk beverages require the

48  Chapter 2  Engineering Tools in Milk-Based Beverages

addition of a stabilizer (Tromp et al., 2004). The mechanism of stabilization by hydrocolloids and stabilizers and their interaction with the milk proteins has been extensively reviewed (Syrbe et al., 1998; Tromp et al., 2004; Corredig et al., 2011). The interaction of protein and polysaccharides plays a vital role in deciding the quality attributes of the product such as structure and texture. These interactions are so modulated that the desirable characteristics can be induced in the product. When proteins and polysaccharides are mixed together, the interaction may lead either to segregation or association, depending on the type of polymer, concentration of the polysaccharides, and the environmental conditions of the solution such as temperature, pH, ionic strength, etc. (Grinberg and Tolstoguzov, 1997; Syrbe et al., 1998; Doubliner et al., 2000; Corredig et al., 2011). Addition of polysaccharides may cause segregative phase separation if they are thermodynamically incompatible with milk proteins. In such cases, solvent-biopolymer interaction is favored, rather than b ­ iopolymer-biopolymer interaction (Tolstoguzov, 1997; Corredig et al., 2011). Associative interactions occur because of electrostatic attraction between oppositely charged portion of proteins and polysaccharides (Doubliner et  al., 2000; Turgeon et  al., 2007). These associative interactions are exploited in preparation of acidified milk beverages, essentially to stabilize casein micelles below their isoelectric point. Net negative charge of casein micelles becomes positive below isoelectric point and then electronegative polysaccharides are made to react with the micelles. The negative charge is then provided by the polysaccharides and thus the system is stabilized. Protein-polysaccharide interactions are complex and are affected by a number of factors related to the molecular weight and charge of the biopolymers, distribution of the charge, ratio between polymers, their concentrations, and environmental conditions of the solution. Protein-polysaccharide interactions have been the focus of research and have been used to modulate the structure of dairy matrices for increasing the quality characteristics of dairy beverages (milk-based beverages). Advanced analytical techniques such as nuclear magnetic resonance (NMR), rheological techniques, spectroscopy, etc. have aided in such customization of properties of milk-based beverages, particularly acidified milk beverages (Corredig et al., 2011). As discussed in casein stabilization, micelles are stable at pH 6.7 owing to the presence of protruding κ-casein chains at the surface. In acidified milk beverages, these κ-casein chains are no longer able to protrude and cause steric destabilization. Beverages may be stabilized by the addition of stabilizers such as pectin, carboxymethylcellulose (CMC), κ-carrageenan, etc. Stabilizers are a class of water soluble polysaccharides with high molecular weight and are known for their use as thickening agents. The ­functions

Chapter 2  Engineering Tools in Milk-Based Beverages    49

of stabilizers are mainly dependent on their ability to increase viscosity, gel formation, and water binding. They are also termed as hydrocolloids and gums. Pectin has been widely used in the preparation of acidified milk beverages. Pectin adsorbs onto the casein micelles as a result of an electrostatic interaction (Tromp et al., 2004). Charged blocks of pectin get adsorbed, while uncharged part stretches to form entropy-rich loops that extend into the solution in a similar way as κ-casein extends into the solution at pH 6.7 (Syrbe et al., 1998; Nakamura et al., 2006; Doubliner et al., 2000; Corredig et al., 2011). Essentially, the protruding κ-casein chains are replaced by chains of pectin to cause steric stabilization in acidified milk beverages, as shown in Fig. 2.2. Tromp et al. (2004) suggested that this non-absorbing pectin portion is only responsible for producing a stable system, but not in maintaining it. They concluded that complexes of casein micelles with absorbed pectin form a self-supporting network, which is eventually responsible for the stability of milk proteins of acidified milk beverages. Sejersen et al. (2007) elucidated the significance of zeta potential in pectin-stabilized acidified milk beverages. Acidification changes the net negative charge on casein micelles to positive (Tuinier et al., 2002). Zeta potential of acidified milk beverage was found to be positive and became negative again by the addition of pectin (Sejersen et al., 2007). This zeta potential becomes negative again by addition of pectin. This negative charge increases with increasing concentration of pectin and causes casein stabilization. The ability to stabilize casein by pectin is also affected by its charge and charge distribution. Kim and Wicker (2011) studied the efficacy of pectin with different charge distributions to stabilize milk proteins. They observed that interactions of pectin with different charge distribution and κ-casein were significantly different. However, interaction with α-s-casein and β-casein was not affected by charge distribution of pectin. Nakamura et al. (2006) ­studied the interaction of high-methoxyl (HM)

Fig. 2.2  Mechanism of stabilization by pectin. Adapted from Tromp, R.H., de Kruif, C.G., van Eijk, M., Rolin, C., 2004. On the mechanism of stabilisation of acidified milk drinks by pectin. Food Hydrocoll. 18 (4), 565–572.

50  Chapter 2  Engineering Tools in Milk-Based Beverages

pectin and soybean soluble polysaccharide (SSPS) in acidified milk beverages and reported that adsorption of pectin occurred from the beginning of acidification and affected the stabilization and rearrangement of casein micelle in the pH range from 5.8 to 5.0. However, SSPS did not interact with casein micelles at pH more than 4.6. SSPS was able to stabilize casein only when the pH dropped below 4.2. The structural differences between HM pectin and SSPS were attributed as the prime reason for their dissimilar behavior in acid milk systems. Jensen et al. (2010) studied the use of HM pectin to stabilize acidified milk drink at two different acidification temperatures of 16°C and 27°C. Temperatures were altered to achieve different particle size of the aggregates. It was inferred that stabilization of the aggregates was attributed to steric repulsive attraction and the presence of HM pectin in a multilayer around the casein aggregates. Parker et al. (1994) had reported similar findings in the study to evaluate the effect of HM pectin on rheology and colloidal stability of acid milk drinks. Further, it was observed that inner layer of pectin was firmly adsorbed and an exterior layer (less firmly adsorbed) protruded in the serum phase (Jensen et al., 2010). Françoise et al. (2009) used low-methoxyl pectin in acid milk drink and observed stable milk proteins at lower pH with decreased micelle hydration. CMC is also widely used as stabilizer in acidified milk beverages. CMC is an anionic polysaccharide and has been used as stabilizer in foods. CMC chains are linear β (1 → 4) linked glucopyranose residues. It is usually preferred over pectin because of its low cost (Janhøj et al., 2008). Stabilization of CMC is quite similar to pectin and involves the adsorption of charged moieties onto casein micelles and causes steric repulsion to prevent flocculation of casein micelles. The non-­ adsorbing CMC also contributes toward stability by increasing the viscosity of serum, thus slowing down the sedimentation of casein particles (Du et al., 2009). Molecular weight and degree of substitution (DS) of CMC have been reported to significantly affect the stability of acidified milk beverages. Du et al. (2009) reported that increase in molecular weight results in better stability of acidified milk beverage, as it results in bigger loop conformation and thus increase the viscosity, which aids in better stability of the beverage. Nakamura et al. (2003) also reported the same findings while using SSPSs. Du et al. (2009) also studied that high molecular weight CMC results in more negative zeta potential thus confirming better stability of acidified milk beverages. Wu et al. (2014) studied the influence of homogenization and the degradation of CMC on the stability of directly acidified milk drinks and yogurt drinks. Homogenization significantly improved the stability of the drinks as indicated by reduced particle size and the sedimentation fraction of the homogenized samples. The effect of homogenization pressure was studied and it was reported that too high

Chapter 2  Engineering Tools in Milk-Based Beverages    51

homogenization pressure (more than 25 MPa) resulted in poor stability of milk proteins. The optimum homogenization pressure of 20 MPa was suggested. It was inferred that intense homogenization resulted in increased number of small protein particles and bare protein particles. Thus, more CMC was required to cover all of these small particles sufficiently and maintain a stable system. Further, homogenization resulted in decrease in molecular weight of CMC, which weakened the stabilization effect of CMC. It was also observed that stability of direct acidified drinks and yogurt drinks increased with increasing CMC concentration. However, the stability decreased during storage at low pH due to degradation of CMC. Exopolysaccharides (EPSs) are structurally and functionally valuable biopolymers secreted by different microorganisms under stress conditions for survival (Sathiyanarayanan et  al., 2017). These are of particular interest in fermented milk beverages, which are produced by in situ development of acidity by lactic acid bacteria. Certain strains of lactic acid bacteria (Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus helveticus, Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus johnsonii, etc.) can produce EPS. They thus serve the dual purposes of developing acidity and producing EPS, which may act as stabilizer and thickener (Ruas-Madiedo et al., 2002; Badel et al., 2011; Corredig et al., 2011), owing to its ability to increase water retention and texture modification. EPS from lactic acid bacteria can be classified as homopolysaccharides and heteropolysaccharides. Homopolysaccharide EPS is composed of only one kind of monosaccharide, whereas several different monosaccharides form heteropolysaccharide EPS (Badel et al., 2011). EPS has been extensively studied for their ability to promote textural and rheological properties in fermented dairy products. In yogurt, the presence of EPS resulted in higher viscosities and less syneresis (Hassan et  al., 2003; Doleyres et al., 2005; Laneuville and Turgeon, 2014). Acid milk products with EPS have denser protein networks as compared with products without EPS (Hassan et al., 2002, 2003). Laneuville and Turgeon (2014) reported better gel strength and lesser syneresis in samples with EPS at 0.01% concentration. However, increase in the concentration to 0.05% resulted in increased syneresis. It was concluded that anionic polysaccharides (EPS, xanthan, and κ-carrageenan) have a major negative effect on the stability of acid milk gels above a certain concentration, because of segregative phase separation. The results suggested that limited protein-polysaccharide interaction favors gel stabilization in acid milk gels. An anionic polysaccharide like EPS bearing low charge density is thus useful in such gels. Other hydrocolloids have also been used in milk beverages for replacing fat. κ-Carrageenan and sodium alginate have been used in

52  Chapter 2  Engineering Tools in Milk-Based Beverages

milk chocolate beverage (Yanes et  al., 2002). Carrageenan acts as a fat replacer, owing to its ability to interact with casein micelles (Syrbe et  al., 1998; Langendorff et  al., 2000). Alginates increase the viscosity of the aqueous phase and thus increase the mouthfeel of low-fat beverages. However, at similar viscosities, κ-carrageenan has been reported to possess better flavor releasing properties than alginates (Yanes et al., 2002). Arancibia et al. (2011) studied the effectiveness of λ-­carrageenan and a blend (50:50) of short- and long-chain inulin as fat replacers in dairy beverages prepared with CMC. It was observed that both λ-carrageenan and the inulin blend could be successfully used as fat replacers in CMC-based dairy beverages. Samples with added λ-carrageenan were more similar to full-fat samples in terms of rheological behavior than samples with inulin blend.

2.7  Low-Fat Milk-Based Beverages Excess dietary fat consumption has been known to be associated with various chronic diseases involving coronary heart disease, type 2 diabetes, obesity, and cancer (Mozaffarian, 2016). WHO reports that worldwide obesity has nearly tripled since 1975. In 2016, more than 1.9 billion adults (representing 39% of world’s adult population) were overweight. Of these, over 650 million (representing 13% of world’s adult population) were obese. Most of the world’s population live in countries where overweight and obesity kills more people than underweight (WHO, 2017). It has been reported that excess consumption of fat is the prime cause of overweight and obesity, followed by sedentary lifestyle and lack of physical activity. Cost of medical care to treat obesity has been reported to be approximately $190 billion in the United States, in 2005 (Cawley and Meyerhoefer, 2012), and has increased significantly since then. Attempts have been made in almost all food sectors to develop low-fat versions of the existing foods. However, stand-alone reduction of fat from foods makes the product suffer quality loss in terms of sensory characteristics, particularly flavor and texture. Fat replacers have been used, so that a significant amount of fat can be replaced with fat replacers, without substantial quality loss. These fat replacers not only contribute sensory characteristics, but also texturize the product. Milk-based beverages are also not an exception to products with high fat content, and therefore have seen a decrease in purchase and consumption. A variety of low-fat milk-based dairy beverages have been developed and introduced in the global market. Before discussing the low-fat milk-based beverages, it is essential to understand the role of fat in contributing texture and sensory qualities of foods. This will help to understand the role and mechanism of fat replacers to develop low calorie or low-fat foods.

Chapter 2  Engineering Tools in Milk-Based Beverages    53

Fat contributes to varied functionalities to foods, including physicochemical properties, structure, texture, flavor, and overall quality of foods. Removal or reduction of fat results in deterioration of food qualities. Fat significantly contributes to texture and mouthfeel. In most liquid foods, fat exists in the form of oil-in-water emulsions as dispersed globules similar to colloidal particles of proteins. The interaction of fat with other colloidal particles increases the viscosity of the product, which is seriously hampered by fat reduction, particularly in milk-based dairy beverages. Viscosity of the product is the most important parameter that affects mouthfeel and thus needs to be altered in low-fat beverages to compensate for reduction of fat (Peng and Yao, 2017). Fat is also incorporated as an emulsion filled in the gels in products like yogurt and fermented milk beverages. The hardness and compressive energy of the gel decreases with increasing fat content or the size of the fat globules (Kim et al., 1996; Gwartney et al., 2004; Foegeding et al., 2011; Peng and Yao, 2017). Composition of fat (fatty acid make up) also affects the properties of foods. Fatty acid composition and the resultant polymorphic form influence properties like spreadability, plasticity, and flow properties (Glibowski et al., 2008). Sensory perception of fat is a complex phenomenon, which involves time-dependent deformation, structural breakdown, and flow of foods during mastication (Guinard and Mazzucchelli, 1996). Product attributes such as creaminess, mouthfeel, thickness, smoothness, etc. are related to fat and the rheological and textural properties related to fat. However, such attributes are difficult to measure and quantify and can only be correlated to the instrumental textural and rheological parameters (Kilcast and Clegg, 2002; Peng and Yao, 2017). During sensory perception of fat, deformation of emulsion results in release of fat and lowers the frictional force (van Aken et al., 2011; Liu et al., 2015). Fat components deposit on the palate because of the interfacial interactions with oral epithelia (Malone et al., 2003a; van Aken et al., 2011). Advanced techniques like tribology and wave spectroscopy can be used to relate oro-sensory perception of fat with instrumental data (Malone et al., 2003a; Peng and Yao, 2017). Thus, it can be concluded that fat contributes significantly to the flavor and body and texture of the products and their oro-sensory perception during mastication and consumption. Reduction of fat results in the decrease in several desirable attributes of foods, which causes serious quality deterioration in foods. Reduction of viscosity is the most common change that occurs in dairy beverages and other liquid foods (Aime et al., 2001; Sakiyan et al., 2004; Simuang et al., 2004; van Aken et al., 2011). Fat is also responsible for carrying fat-soluble flavor and aroma compounds and thus contributes to the overall flavor profile of the foods. Therefore, reduction of fat also results in the loss of characteristic flavor profile of the food and

54  Chapter 2  Engineering Tools in Milk-Based Beverages

makes the food less appealing (Malone et al., 2003b; Childs and Drake, 2009; Raju and Pal, 2009; Tekin et al., 2017). Further, owing to the effect of taste-taste and odor-taste interactions, fat also contributes to the perception of other sensory attributes such as bitterness, astringency, sour, or salty (Khetra et al., 2016). Fat may suppress the perception of other sensory attributes, essentially by increasing the viscosity and causing a mouth-coating sensation (Lynch et al., 1993; Valentova and Pokorný, 1998; van Aken et al., 2011). Moreover, most of the dairy beverages are prepared after fermentation of milk by suitable starter organisms. During fermentation, fat may be lipolyzed leading to the production of fatty acids and several fat-based flavor compounds, which contributes to the overall flavor profile of the fermented dairy products. Reduction in fat may also result in reduced generation of these flavor compounds. In addition, some undesirable flavors and odors can be produced (Drake et al., 2010). Reduced fat products commonly lack creaminess and the desired mouthfeel, contributed respectively by the fat globules and their contribution to viscosity of the liquid. Mouthfeel can be increased to a large extent by addition of polysaccharide in place of fat. However, creaminess or oiliness can be incorporated in the product by altering the particle size and making them equivalent to the size of fat globules. A large number of fat replacers are being used for these purposes.

2.7.1  Fat Replacers As stand-alone reduction of fat in foods causes quality deterioration, fat replacers are being used to develop low-fat foods. These fat replacers are broadly classified as fat substitutes and fat mimetics (Ognean et al., 2006; Peng and Yao, 2017). Fat substitutes are ingredients with similar chemical structure and physicochemical properties to that of fat (Ognean et  al., 2006; Peng and Yao, 2017). However, they are indigestible or have lesser calorific values (Sandrou and Arvanitoyannis, 2000; Ognean et  al., 2006). Fat substitutes are lipids in nature and are called lipid-based fat replacers. Fat substitutes are either chemically synthesized or derived from natural fats by enzymatic modification. Many fat substitutes are stable at cooking and frying temperatures (Akoh and Decker, 1995; Peng and Yao, 2017). Olestra, Salatrim, and Caprenin are the most common commercial lipid-based fat replacers. Olestra is synthesized through the esterification of sucrose and long-chain fatty acids (C12–C20), whereas Salatrim and Caprenin are produced through substituting a certain proportion of long-chain fatty acids with short-chain fatty acids (Akoh and Decker, 1995; Ognean et al., 2006; Peng and Yao, 2017). They have been used in a wide range of low-fat foods for ­modulating texture and other functionalities of the products (Peng and Yao, 2017).

Chapter 2  Engineering Tools in Milk-Based Beverages    55

Their properties are dependent, essentially on the fatty acid profile created during synthesis of these substitutes. These substitutes can also be used to replace frying oil, shortenings, and cocoa butter (Osborn and Akoh, 2002; Ognean et al., 2006; Peng and Yao, 2017). Contrary to the substitutes, fat mimetics have distinctly different chemical structures from that of fat. Fat mimetics are generally carbohydrates or proteins, with diverse functional characteristics that assist in simulating physicochemical attributes and sensory perception of fat. They generally contribute viscosity and mouthfeel to low-fat products (Ognean et al., 2006; Peng and Yao, 2017). The chemical nature of protein or carbohydrate-based fat replacers is entirely different from that of fat and therefore, they cannot imitate fats at molecular level. However, these can be used to produce similar functionalities through contribution to viscosity and mouthfeel of the products, so that the fat can be replaced. Further, they can be produced in sizes similar to the size of fat globules present in emulsions to simulate the interactions between fat globules and oral epithelia during mastication/consumption of foods (Peng and Yao, 2017). Carbohydrate-based fat replacers are the most commonly used fat replacers in low-fat milk beverages. Common carbohydrate-based fat replacers include starch and starch derivatives, maltodextrins, polydextrose, gums, and fibers. Peng and Yao (2017), in their review on carbohydrate-based fat replacers have proposed a mechanism describing fat replacement with carbohydrates in liquid foods. They suggested that carbohydrates are capable of replacing fat owing to their ability to contribute to viscosity and/or mimic the sensory perception in particulate forms. It is suggested that textural and sensory properties of foods where fat is present in oil-in-water emulsions is primarily because of interactions between colloidal particles (fat and proteins) of foods. The removal of fat results in thinning the mouthfeel due to reduced particle-particle interactions. Thus, microparticulated granular particles of carbohydrates may induce similar particle-particle interactions in low-fat liquid foods and contribute to creaminess and enhanced mouthfeel. Nongranular carbohydrates contribute to viscosity enhancement and thus increase mouthfeel of beverages (Peng and Yao, 2017). Several low-fat dairy beverages have been developed worldwide and produced commercially. Inulin, a type of fiber, is most widely used and considered to be the most appropriate replacer in milkbased beverages (Meyer et al., 2011a). Inulin is a carbohydrate built up from β (2,1)-linked fructosyl residues, mostly ending with a glucose residue. It is a natural component of several fruits and vegetables and is obtained mainly from chicory roots (Villegas and Costell, 2007). On the basis of degree of polymerization (DP), it has been classified as oligofructose, native, and long-chain inulin. The DP of these types of

56  Chapter 2  Engineering Tools in Milk-Based Beverages

Table 2.1  Types of Inulin: Their Characteristics and Applications Type of Inulin

Degree of Polymerization

Oligofructose

Ranges from 2 to 8 with an average of 4

Native

Approximately 12

Long chain

Ranges from 10 to 60 with an average of 23

Properties

Applications

References

More soluble and sweeter than native inulin Intermediate properties

To replace sugar and to improve mouthfeel

Meyer et al. (2011a)

More thermal stability, less soluble, and more viscous

Used as fat substitute and texture modifier

Villegas and Costell (2007) Wada et al. (2005) and Coussement (1999)

inulins is summarized in Table 2.1. Inulin is not only a fat replacer but also provides multiple benefits as a low calorie sweetener, prebiotic, and a dietary fiber. These technological and functional properties of inulin are based on its chain length or DP as represented in Table 2.1. Low-fat dairy products prepared using inulin as fat replacer have improved creaminess (Guven et  al., 2005; Paseephol et  al., 2008; Cardarelli et al., 2008; González-Tomás et al., 2009; Guggisberg et al., 2009). Inulin does not affect the rheological and sensory qualities of the product, when added in lesser amounts (less than 2 g per 100 g). However, as the concentration of inulin increases, it significantly modifies the texture of dairy products, besides influencing the sensory properties (Meyer et al., 2011a). Inulin has been used as a preferred fat replacer in several dairy beverages including fermented milk, whole and skim milk beverage, kefir, etc. (Villegas and Costell, 2007; De Castro et al., 2009; de Souza Oliveira et al., 2009; Tiwari et al., 2015). Application of 2%–5% oligofructose in whole milk fermented beverage showed time-­dependent shear thinning behavior (De Castro et  al., 2009). The addition of 5% long-chain inulin to low-fat fermented milk did not show shear thinning, but it did increase significantly, the apparent viscosity values below 50 s−1 (de Souza Oliveira et al., 2009). Villegas and Costell (2007) studied the effect of inulin average chain length and fat content in a model milk beverage system. Short, native, and long-chain inulin were used in the concentration range of 2%–10% in milk beverage model systems with different fat content with and without the addition of κ-carrageenan. No significant differences were observed

Chapter 2  Engineering Tools in Milk-Based Beverages    57

in the viscosity of the beverage with all three types of inulin up to 6% level. Long-chain inulin at higher concentrations of 8%–10% resulted in viscosity similar to that of whole milk samples and was perceived as creamier. Villegas et al. (2007) observed that to match the viscosity of whole milk vanilla beverage with that of skim milk beverage, oligofructose, native, and long-chain inulin should be added in the range of 4%–10%, 6%–8%, and 4%–6%, respectively. Thus, long-chain inulin was concluded to be the more effective viscosifier in such beverages. Meyer et  al. (2011b) also validated the efficacy of long-chain inulin to match the characteristic of milk fat, through tribological measurements to determine the effect of inulin as texture modifier. It was observed that long-chain inulin was more effective than native inulin in reducing the frictional coefficients equal to the value of frictional coefficient of full-fat milk.

2.8  Functional Milk Beverages Functional foods are being developed in almost every sector of foods and research in the area has attracted much attention in the last decade. Among functional foods, beverages form the most active category because of the reasons including convenience, ease of distribution and storage, and ability to incorporate a large number of functional or bioactive ingredients conferring physiological functionality to the product (Corbo et al., 2014). Dairy-based functional beverages form the most important and potential segment of functional beverages. Other segments include vegetable and fruit beverages and sports and energy drinks (Corbo et al., 2014). Özer and Kirmaci (2010) classified functional dairy beverages into fortified dairy beverages and whey-based beverages. Fortified dairy beverages include all the beverages manufactured by incorporating probiotics, prebiotics, minerals, vitamins, ω-3 fatty acids, herbal nutraceuticals, and any other functional ingredient. Of these, probiotic dairy beverages share the majority of the market. A large number of probiotic dairy beverages have been manufactured and commercialized. Similarly, a number of bioactive ingredients have been incorporated into dairy beverages. However, this section of the chapter will be restricted to the structural modifications carried out to achieve the desired objective. The objectives of structural modification include: (1) to protect the functional ingredient from environmental conditions during storage and digestion; (2) to release the functional ingredient at its target site without damage to its functional properties; and (3) to mask the sensory attributes of the functional ingredients so that it does not affect the sensory profile of the product and consumer acceptance.

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A number of interventions have been attempted for achieving these targets. Microencapsulation has been used for protecting bioactive components and for their controlled release in the intestine. The coat material and the properties of the coat are such designed that they remain stable at acidic pH and as soon as they get alkaline conditions, dissolution of coat takes place resulting in the release of the bioactive materials (Kailasapathy and Champagne, 2011). A number of functional dairy beverages have been developed using microencapsulation (Kailasapathy, 2006; Anal and Singh, 2007; Homayouni et al., 2008; De Prisco and Mauriello, 2016). During microencapsulation, the selection of capsule materials as well as the techniques used in fabrication of microcapsules is of prime significance as it decides the properties (size, morphology, porosity, etc.) of the capsule. These properties eventually affect the degree of protection of the bioactive component and its release at target site of action (De Prisco and Mauriello, 2016). Nanostructures have been heavily researched upon recently for their potential in target delivery of functional ingredients. Nanostructured systems in food include polymeric nanoparticles, liposomes, nanoemulsions, and microemulsions. These structures are proven to improve bioavailability of nutrients, facilitate controlled release, and also protect the functional ingredient during manufacture and storage of foods (Pathakoti et  al., 2017). The functions of nanoemulsions are similar to those of microemulsions. They also improve solubility, stability, and bioavailability of mostly oil-soluble functional ingredients because of the small droplet size and high kinetic stability (Sari et al., 2015). Nanopowdered chitosan (Park et al., 2010; Seo et al., 2011), nanoginseng (Ahn and Kwak, 2011), nanopowdered peanut sprout (Ahn et al., 2013), etc., have been incorporated in milk and yogurt for desired physiological benefits. Double emulsions are the emulsions in which the dispersed phase is itself an emulsion present as fine droplets. They are of two types: water-in-oil-in-water (W/O/W) and oil-in-water-in-oil (O/W/O). In W/O/W, water is first dispersed in oil which is then dispersed in another water phase. Similarly for O/W/O, oil is first dispersed in water and then this emulsion is dispersed in a second oil phase. Double emulsions are applicable as protective encapsulating agents to hydrophilic and hydrophobic bioactive substances in the internal droplets of the emulsion. They are used in applications where controlled (sustained and delayed) release of bioactive ingredients is of importance (Lamba et al., 2015). They have been applied in industrial fields such as pharmaceuticals and cosmetics for target delivery of drugs, vaccines and antigens, administration of insulin, and removal of toxic material. Some of the food applications of double emulsions are encapsulation and controlled release of flavors, bioactive compounds, microorganisms or probiotics (Pimentel-González et  al., 2009), vitamins

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(Li  et  al., 2012), and minerals (Jiménez-Alvarado et  al., 2009). In recent times, certain medicinal herbs that constitute an important class of plant bioactives have gained attention as beneficial food additives. Many of such therapeutic herbs cannot be used with foods, owing to their unacceptable sensory properties. Another major constraint of adding such bioactives in food is their decreased bioavailability in vivo. They are sensitive to surrounding environment stresses like pH, ionic strength, light, temperature, oxygen, and gastrointestinal (GI) conditions during transit. The bioavailability of such active components could be significantly enhanced, if coupled with a suitable delivery vehicle. Lamba et al. (2017) demonstrated that guggul (Commiphora mukul) extract, a herb that reportedly is beneficial against cardiovascular problems, when encapsulated in a suitable double emulsion matrix provided protection against hypercholesterolemia to laboratory animals (rats).

2.9 Conclusion Market trend indicates tremendous growth in milk-based beverages globally. Many novel beverages are being introduced in the market every now and then. Acidified milk beverages and low calorie milk beverages represent a significant share of the global beverage market. Development of these beverages requires detailed understanding of protein-polysaccharide interactions and the resultant stabilization or destabilization mechanisms. Fat replacers are being used to develop low calorie beverages. The understanding of sensory perception of fat is of paramount importance during its simulation by fat replacers. Functional beverages have grown significantly in the present decade. Innovations, particularly in the area of protecting the active ingredient from external environment and to control its release so that it can reach the target site of action without degradation, are gaining momentum in the area of beverage science. Research and development efforts worldwide have contributed significantly to these developments.

References Ahn, Y.J., Kwak, H.S., 2011. The physicochemical and sensory properties of yogurt supplemented with dispersible nanoginseng during storage. J. Dairy Sci. 94, 540. E-Supplement. 1. Ahn, Y.J., Ganesan, P., Kwak, H.S., 2013. Effect of nanopowdered peanut sprouts on physicochemical and sensory properties of milk. Korean J. Food Sci. Anim. Resour. 33 (1), 9–15. Aime, D.B., Arntfield, S.D., Malcolmson, L.J., Ryland, D., 2001. Textural analysis of fat reduced vanilla ice cream products. Food Res. Int. 34 (2), 237–246. Akoh, C.C., Decker, E.A., 1995. Lipid-based fat substitutes. Crit. Rev. Food Sci. Nutr. 35 (5), 405–430.

60  Chapter 2  Engineering Tools in Milk-Based Beverages

Anal, A.K., Singh, H., 2007. Recent advances in microencapsulation of probiotics for industrial applications and targeted delivery. Trends Food Sci. Technol. 18 (5), 240–251. Arancibia, C., Costell, E., Bayarri, S., 2011. Fat replacers in low-fat carboxymethyl cellulose dairy beverages: color, rheology, and consumer perception. J. Dairy Sci. 94 (5), 2245–2258. Badel, S., Bernardi, T., Michaud, P., 2011. New perspectives for Lactobacilli exopolysaccharides. Biotechnol. Adv. 29 (1), 54–66. Bogue, J., Troy, A.J., 2016. Functional beverages: market trends and market oriented new product designs. In: Shahidi, F., Alasalvar, C. (Eds.), Handbook of Functional Beverages and Human Health. CRC Press, Taylor and Francis Group, pp. 3–16. Cardarelli, H.R., Aragon-Alegro, L.C., Alegro, J.H., de Castro, I.A., Saad, S.M., 2008. Effect of inulin and Lactobacillus paracasei on sensory and instrumental texture properties of functional chocolate mousse. J. Sci. Food Agric. 88 (8), 1318–1324. Cawley, J., Meyerhoefer, C., 2012. The medical care costs of obesity: an instrumental variables approach. J. Health Econ. 31 (1), 219–230. Chen, B., McClements, D.J., Decker, E.A., 2013. Design of foods with bioactive lipids for improved health. Annu. Rev. Food Sci. Technol. 4, 35–56. Childs, J.L., Drake, M., 2009. Consumer perception of fat reduction in cheese. J. Sens. Stud. 24 (6), 902–921. Christie, W.W., 1995. Composition and structure of milk lipids. In: Fox, P.F. (Ed.), Advanced Dairy Chemistry. 2: Lipids, second ed. Chapman and Hall, London, pp. 1–36. Corbo, M.R., Bevilacqua, A., Petruzzi, L., Casanova, F.P., Sinigaglia, M., 2014. Functional beverages: the emerging side of functional foods. Compr. Rev. Food Sci. Food Saf. 13 (6), 1192–1206. Corredig, M., Sharafbafi, N., Kristo, E., 2011. Polysaccharide–protein interactions in dairy matrices, control and design of structures. Food Hydrocoll. 25 (8), 1833–1841. Coussement, P.A., 1999. Inulin and oligofructose: safe intakes and legal status. J. Nutr. 129 (7), 1412S–1417S. Dalgleish, D.G., Corredig, M., 2012. The structure of the casein micelle of milk and its changes during processing. Annu. Rev. Food Sci. Technol. 3, 449–467. De Castro, F.P., Cunha, T.M., Barreto, P.L., Amboni, R.D.D., Prudencio, E.S., 2009. Effect of oligofructose incorporation on the properties of fermented probiotic lactic beverages. Int. J. Dairy Technol. 62 (1), 68–74. de Kruif, C.G., 1998. Supra-aggregates of casein micelles as a prelude to coagulation. J. Dairy Sci. 81 (11), 3019–3028. De Prisco, A., Mauriello, G., 2016. Probiotication of foods: a focus on microencapsulation tool. Trends Food Sci. Technol. 48, 27–39. de Souza Oliveira, R.P., Perego, P., Converti, A., De Oliveira, M.N., 2009. The effect of inulin as a prebiotic on the production of probiotic fibre-enriched fermented milk. Int. J. Dairy Technol. 62 (2), 195–203. Diarrassouba, F., Garrait, G., Remondetto, G., Subirade, M., 2017. β-Lactoglobulin-based nano and microparticulate systems for the protection and delivery of bioactives. In: Engineering Foods for Bioactives Stability and Delivery. Springer, New York, pp. 199–224. Dickinson, E., 2007. Food colloids… How do interactions of ingredients control structure, stability and rheology? Curr. Opin. Colloid Interface Sci. 4 (12), 155–157. Dickinson, E., 2017. Biopolymer-based particles as stabilizing agents for emulsions and foams. Food Hydrocoll. 68, 219–231. Doleyres, Y., Schaub, L., Lacroix, C., 2005. Comparison of the functionality of exopolysaccharides produced in situ or added as bioingredients on yogurt properties. J. Dairy Sci. 88 (12), 4146–4156. Doubliner, J.L., Garnier, C., Renard, D., Sanchez, C., 2000. Protein–polysaccharide interactions. Curr. Opin. Colloid Interface Sci. 5 (3), 202–214.

Chapter 2  Engineering Tools in Milk-Based Beverages    61

Drake, M.A., Miracle, R.E., McMahon, D.J., 2010. Impact of fat reduction on flavor and flavor chemistry of Cheddar cheeses. J. Dairy Sci. 93 (11), 5069–5081. Du, B., Li, J., Zhang, H., Huang, L., Chen, P., Zhou, J., 2009. Influence of molecular weight and degree of substitution of carboxymethylcellulose on the stability of acidified milk drinks. Food Hydrocoll. 23 (5), 1420–1426. Ezhilarasi, P.N., Karthik, P., Chhanwal, N., Anandharamakrishnan, C., 2013. Nanoencapsulation techniques for food bioactive components: a review. Food Bioprocess Technol. 6 (3), 628–647. Farrell, H.M., Malin, E.L., Brown, E.M., Qi, P.X., 2006. Casein micelle structure: what can be learned from milk synthesis and structural biology? Curr. Opin. Colloid Interface Sci. 11 (2), 135–147. Fathi, M., Martín, Á., McClements, D.J., 2014. Nanoencapsulation of food ingredients using carbohydrate based delivery systems. Trends Food Sci. Technol. 39 (1), 18–39. Foegeding, E.A., Daubert, C.R., Drake, M.A., Essick, G., Trulsson, M., Vinyard, C.J., Van De Velde, F., 2011. A comprehensive approach to understanding textural properties of semi-and soft-solid foods. J. Texture Stud. 42 (2), 103–129. Fox, P.F., McSweeney, P.L.H., 1998. Dairy Chemistry and Biochemistry. Blackie Academic & Professional, London. Françoise, K.A., Kablan, T., Kamenan, A., Lagaude, A., 2009. Rheological and biochemical properties of acidified milk/pectin co-gels. Eur. J. Sci. Res. 25 (4), 584–596. Glibowski, P., Zarzycki, P., Krzepkowska, M., 2008. The rheological and instrumental textural properties of selected table fats. Int. J. Food Prop. 11 (3), 678–686. González-Tomás, L., Bayarri, S., Costell, E., 2009. Inulin-enriched dairy desserts: physicochemical and sensory aspects. J. Dairy Sci. 92 (9), 4188–4199. Grinberg, V.Y., Tolstoguzov, V.B., 1997. Thermodynamic incompatibility of proteins and polysaccharides in solutions. Food Hydrocoll. 11 (2), 145–158. Guggisberg, D., Cuthbert-Steven, J., Piccinali, P., Bütikofer, U., Eberhard, P., 2009. Rheological, microstructural and sensory characterization of low-fat and whole milk set yoghurt as influenced by inulin addition. Int. Dairy J. 19 (2), 107–115. Guinard, J.X., Mazzucchelli, R., 1996. The sensory perception of texture and mouthfeel. Trends Food Sci. Technol. 7 (7), 213–219. Gupta, P., Narasimhan, S., 2016. Dairy beverages in India: a lip-smacking billion dollar opportunity. Tata Strategic Management Group. B-1001, Marathon Futurex, Mumbai. Guven, M., Yasar, K., Karaca, O.B., Hayaloglu, A.A., 2005. The effect of inulin as a fat replacer on the quality of set-type low-fat yogurt manufacture. Int. J. Dairy Technol. 58 (3), 180–184. Gwartney, E.A., Larick, D.K., Foegeding, E.A., 2004. Sensory texture and mechanical properties of stranded and particulate whey protein emulsion gels. J. Food Sci. 69 (9), S333–S339. Hassan, A.N., Frank, J.F., Qvist, K.B., 2002. Direct observation of bacterial exopolysaccharides in dairy products using confocal scanning laser microscopy. J. Dairy Sci. 85 (7), 1705–1708. Hassan, A.N., Ipsen, R., Janzen, T., Qvist, K.B., 2003. Microstructure and rheology of yogurt made with cultures differing only in their ability to produce exopolysaccharides. J. Dairy Sci. 86 (5), 1632–1638. Homayouni, A., Azizi, A., Ehsani, M.R., Yarmand, M.S., Razavi, S.H., 2008. Effect of microencapsulation and resistant starch on the probiotic survival and sensory properties of synbiotic ice cream. Food Chem. 111 (1), 50–55. Horne, D.S., 2006. Casein micelle structure: models and muddles. Curr. Opin. Colloid Interface Sci. 11 (2), 148–153. Horne, D.S., 2009. Casein micelle structure and stability. In: Thompson, A., Boland, M., Singh, H. (Eds.), Milk Proteins: From Expression to Food. Academic Press, Elsevier, pp. 133–162.

62  Chapter 2  Engineering Tools in Milk-Based Beverages

http://www.arlafoods.co.uk, 2016. https://www.arlafoods.co.uk/overview/news--press/ 2016/pressrelease/arla-to-triple-its-business-in-the-global-beverage-market1539253/. (Accessed 10 November, 2017). Ipsen, R., Otte, J., 2007. Self-assembly of partially hydrolysed α-lactalbumin. Biotechnol. Adv. 25 (6), 602–605. Ipsen, R., Otte, J., Qvist, K.B., 2001. Molecular self-assembly of partially hydrolysed alpha-lactalbumin resulting in strong gels with a novel microstructure. J. Dairy Res. 68 (2), 277–286. Janhøj, T., Frøst, M.B., Ipsen, R., 2008. Sensory and rheological characterization of acidified milk drinks. Food Hydrocoll. 22 (5), 798–806. Jensen, R.G., 2002. The composition of bovine milk lipids: January 1995 to December 2000. J. Dairy Sci. 85 (2), 295–350. Jensen, R.G., Clark, R.W., 1988. Lipid composition and properties. In: Wong, N.P., Jenness, R., Keeney, M., Marth, E.H. (Eds.), Fundamentals of Dairy Chemistry, third ed. Van Nostrand, New York, pp. 171–213. Jensen, R.G., Newberg, D.S., 1995. Milk lipids B. Bovine milk lipids. In: Jensen, R.G. (Ed.), Handbook of Milk Composition. Academic Press, San Diego, CA, pp. 543–575. Jensen, S., Rolin, C., Ipsen, R., 2010. Stabilisation of acidified skimmed milk with HM pectin. Food Hydrocoll. 24 (4), 291–299. Jiménez-Alvarado, R., Beristain, C.I., Medina-Torres, L., Román-Guerrero, A., VernonCarter, E.J., 2009. Ferrous bisglycinate content and release in W 1/O/W 2 multiple emulsions stabilized by protein–polysaccharide complexes. Food Hydrocoll. 23 (8), 2425–2433. Kailasapathy, K., 2006. Survival of free and encapsulated probiotic bacteria and their effect on the sensory properties of yoghurt. LWT- Food Sci. Technol. 39 (10), 1221–1227. Kailasapathy, K., Champagne, C.P., 2011. Trends in the microencapsulation of probiotics for application in dairy products. Agro Food Ind. Hi Tech 22 (2), 25. Kang, M.K., Dai, J., Kim, J.C., 2012. Ethylcellulose microparticles containing chitosan and gelatin: pH-dependent release caused by complex coacervation. J. Ind. Eng. Chem. 18 (1), 355–359. Khetra, Y., Kanawjia, S.K., Puri, R., 2016. Selection and optimization of salt replacer, flavour enhancer and bitter blocker for manufacturing low sodium Cheddar cheese using response surface methodology. LWT- Food Sci. Technol. 72, 99–106. Kilcast, D., Clegg, S., 2002. Sensory perception of creaminess and its relationship with food structure. Food Qual. Prefer. 13 (7), 609–623. Kim, Y., Wicker, L., 2011. Charge domain of modified pectins influence interaction with acidified caseins. Food Hydrocoll. 25 (3), 419–425. Kim, K.H., Gohtani, S., Yamano, Y., 1996. Effects of oil droplets on physical and sensory properties of o/w emulsion agar gel. J. Texture Stud. 27 (6), 655–670. Lamba, H., Sathish, K., Sabikhi, L., 2015. Double emulsions: emerging delivery system for plant bioactives. Food Bioprocess Technol. 8 (4), 709–728. Lamba, H., Sabikhi, L., Aggarwal, D., Choudhary, U., Reddi, S., Kapila, S., Kapila, R., 2017. Double emulsion-encapsulated guggul exhibits improved in vivo hypocholesterolaemic action in rats. Int. J. Food Sci. Technol. https://doi.org/10.1111/ijfs.13637. Laneuville, S.I., Turgeon, S.L., 2014. Microstructure and stability of skim milk acid gels containing an anionic bacterial exopolysaccharide and commercial polysaccharides. Int. Dairy J. 37 (1), 5–15. Langendorff, V., Cuvelier, G., Michon, C., Launay, B., Parker, A., 2000. Effects of carrageenan type on the behaviour of carrageenan/milk mixtures. Food Hydrocoll. 14 (4), 273–280. Lesmes, U., McClements, D.J., 2009. Structure–function relationships to guide rational design and fabrication of particulate food delivery systems. Trends Food Sci. Technol. 20 (10), 448–457.

Chapter 2  Engineering Tools in Milk-Based Beverages    63

Li, Y., Hu, M., Xiao, H., Du, Y., Decker, E.A., McClements, D.J., 2010. Controlling the functional performance of emulsion-based delivery systems using multi-component biopolymer coatings. Eur. J. Pharm. Biopharm. 76 (1), 38–47. Li, B., Jiang, Y., Liu, F., Chai, Z., Li, Y., Li, Y., Leng, X., 2012. Synergistic effects of whey protein–polysaccharide complexes on the controlled release of lipid-soluble and water-soluble vitamins in W1/O/W2 double emulsion systems. Int. J. Food Sci. Technol. 47 (2), 248–254. Liu, K., Stieger, M., van der Linden, E., van de Velde, F., 2015. Fat droplet characteristics affect rheological, tribological and sensory properties of food gels. Food Hydrocoll. 44, 244–259. Liu, F., Ma, C., Gao, Y., McClements, D.J., 2017. Food-grade covalent complexes and their application as nutraceutical delivery systems: a review. Compr. Rev. Food Sci. Food Saf. 16 (1), 76–95. Lynch, J., Liu, Y.H., Mela, D.J., MacFie, H.J.H., 1993. A time-intensity study of the effect of oil mouth coatings on taste perception. Chem. Senses 18 (2), 121–129. MacGibbon, A.K.H., Taylor, M.W., 2006. Composition and structure of bovine milk lipids. In: Advanced Dairy Chemistry Volume 2: Lipids. Springer US, pp. 1–42. Malone, M.E., Appelqvist, I.A.M., Norton, I.T., 2003a. Oral behaviour of food hydrocolloids and emulsions. Part  1. Lubrication and deposition considerations. Food Hydrocoll. 17 (6), 763–773. Malone, M.E., Appelqvist, I.A.M., Norton, I.T., 2003b. Oral behaviour of food hydrocolloids and emulsions. Part  2. Taste and aroma release. Food Hydrocoll. 17 (6), 775–784. McClements, D.J., Li, Y., 2010. Structured emulsion-based delivery systems: controlling the digestion and release of lipophilic food components. Adv. Colloid Interf. Sci. 159 (2), 213–228. Meyer, D., Bayarri, S., Tárrega, A., Costell, E., 2011a. Inulin as texture modifier in dairy products. Food Hydrocoll. 25 (8), 1881–1890. Meyer, D., Vermulst, J., Tromp, R.H., De Hoog, E.H.A., 2011b. The effect of inulin on tribology and sensory profiles of skimmed milk. J. Texture Stud. 42 (5), 387. Morrison, W.R., 1970. Milk lipids. In: Gunstone, F.D. (Ed.), Topics in Lipid Chemistry-I. Logos Press, London, pp. 51–106. Moschakis, T., Biliaderis, C.G., 2017. Biopolymer-based coacervates: structures, functionality and applications in food products. Curr. Opin. Colloid Interface Sci. 28, 96–109. Moschakis, T., Dergiade, I., Lazaridou, A., Biliaderis, C.G., Katsanidis, E., 2017. Modulating the physical state and functionality of phytosterols by emulsification and organogel formation: application in a model yogurt system. J. Funct. Foods 33, 386–395. Mozaffarian, D., 2016. Dietary and policy priorities for cardiovascular disease, diabetes, and obesity. Circulation 133 (2), 187–225. Nakamura, A., Furuta, H., Kato, M., Maeda, H., Nagamatsu, Y., 2003. Effect of soybean soluble polysaccharides on the stability of milk protein under acidic conditions. Food Hydrocoll. 17 (3), 333–343. Nakamura, A., Yoshida, R., Maeda, H., Corredig, M., 2006. The stabilizing behaviour of soybean soluble polysaccharide and pectin in acidified milk beverages. Int. Dairy J. 16 (4), 361–369. Ognean, C.F., Darie, N., Ognean, M., 2006. Fat replacers: review. J. Agroaliment. Process. Technol. 12 (2), 433–442. Osborn, H.T., Akoh, C.C., 2002. Structured lipids-novel fats with medical, nutraceutical, and food applications. Compr. Rev. Food Sci. Food Saf. 1 (3), 110–120. Özer, B.H., Kirmaci, H.A., 2010. Functional milks and dairy beverages. Int. J. Dairy Technol. 63 (1), 1–15. Park, J.H., Hong, E.K., Ahn, J., Kwak, H.S., 2010. Properties of nanopowdered chitosan and its cholesterol lowering effect in rats. Food Sci. Biotechnol. 19 (6), 1457–1462.

64  Chapter 2  Engineering Tools in Milk-Based Beverages

Parker, A., Boulenguer, P., Kravtchenko, T.P., 1994. Effect of the addition of high methoxy pectin on the rheology and colloidal stability of acid milk drinks. In: Food Hydrocolloids. Springer US, pp. 307–312. Paseephol, T., Small, D.M., Sherkat, F., 2008. Rheology and texture of set yogurt as affected by inulin addition. J. Texture Stud. 39 (6), 617–634. Patel, A.R., Velikov, K.P., 2011. Colloidal delivery systems in foods: a general comparison with oral drug delivery. LWT- Food Sci. Technol. 44 (9), 1958–1964. Pathakoti, K., Manubolu, M., Hwang, H.M., 2017. Nanostructures: current uses and future applications in food science. J. Food Drug Anal. 25 (2), 245–253. Peng, X., Yao, Y., 2017. Carbohydrates as fat replacers. Annu. Rev. Food Sci. Technol. 8, 331–351. Pimentel-González, D.J., Campos-Montiel, R.G., Lobato-Calleros, C., Pedroza-Islas, R., Vernon-Carter, E.J., 2009. Encapsulation of Lactobacillus rhamnosus in double emulsions formulated with sweet whey as emulsifier and survival in simulated gastrointestinal conditions. Food Res. Int. 42 (2), 292–297. Raju, P.N., Pal, D., 2009. The physico-chemical, sensory, and textural properties of Misti Dahi prepared from reduced fat buffalo milk. Food Bioprocess Technol. 2 (1), 101–108. Ruas-Madiedo, P., Hugenholtz, J., Zoon, P., 2002. An overview of the functionality of exopolysaccharides produced by lactic acid bacteria. Int. Dairy J. 12 (2), 163–171. Sagis, L.M., Veerman, C., van der Linden, E., 2004. Mesoscopic properties of semi-­ flexible amyloid fibrils. Langmuir 20 (3), 924–927. Sakiyan, O., Sumnu, G., Sahin, S., Bayram, G., 2004. Influence of fat content and emulsifier type on the rheological properties of cake batter. Eur. Food Res. Technol. 219 (6), 635–638. Sandrou, D.K., Arvanitoyannis, I.S., 2000. Low-fat/calorie foods: current state and perspectives. Crit. Rev. Food Sci. Nutr. 40 (5), 427–447. Santana, R.C., Perrechil, F.A., Sato, A.C.K., Cunha, R.L., 2011. Emulsifying properties of collagen fibers: effect of pH, protein concentration and homogenization pressure. Food Hydrocoll. 25 (4), 604–612. Sari, T.P., Mann, B., Kumar, R., Singh, R.R.B., Sharma, R., Bhardwaj, M., Athira, S., 2015. Preparation and characterization of nanoemulsion encapsulating curcumin. Food Hydrocoll. 43, 540–546. Sathiyanarayanan, G., Dinesh Kumar, K., Yang, Y.H., 2017. Microbial exopolysaccharidemediated synthesis and stabilization of metal nanoparticles. Crit. Rev. Microbiol. 43 (6), 1–22. Schmidt, D.G., 1982. Association of caseins and casein micelle structure. Dev. Dairy Chem. 1, 61–86. Scholten, E., Moschakis, T., Biliaderis, C.G., 2014. Biopolymer composites for engineering food structures to control product functionality. Food Struct. 1 (1), 39–54. Sejersen, M.T., Salomonsen, T., Ipsen, R., Clark, R., Rolin, C., Engelsen, S.B., 2007. Zeta potential of pectin-stabilised casein aggregates in acidified milk drinks. Int. Dairy J. 17 (4), 302–307. Seo, M.H., Chang, Y.H., Lee, S., Kwak, H.S., 2011. The physicochemical and sensory properties of milk supplemented with ascorbic acid-soluble nano-chitosan during storage. Int. J. Dairy Technol. 64 (1), 57–63. Simuang, J., Chiewchan, N., Tansakul, A., 2004. Effects of fat content and temperature on the apparent viscosity of coconut milk. J. Food Eng. 64 (2), 193–197. Swaisgood, H.E., 1992. Chemistry of the caseins. Adv. Dairy Chem. 1, 63–110. Syrbe, A., Bauer, W.J., Klostermeyer, H., 1998. Polymer science concepts in dairy systems—an overview of milk protein and food hydrocolloid interaction. Int. Dairy J. 8 (3), 179–193. Tekin, E., Sahin, S., Sumnu, G., 2017. Physicochemical, rheological, and sensory properties of low-fat ice cream designed by double emulsions. Eur. J. Lipid Sci. Technol. 119, 1600505.

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Tiwari, A., Sharma, H.K., Kumar, N., Kaur, M., 2015. The effect of inulin as a fat replacer on the quality of low-fat ice cream. Int. J. Dairy Technol. 68 (3), 374–380. Tolstoguzov, V.B., 1997. Protein-polysaccharide interactions. In: Food Science and Technology. Marcel Dekker, New York, pp. 171–198. Tromp, R.H., de Kruif, C.G., van Eijk, M., Rolin, C., 2004. On the mechanism of stabilisation of acidified milk drinks by pectin. Food Hydrocoll. 18 (4), 565–572. Tuinier, R., Rolin, C., De Kruif, C.G., 2002. Electrosorption of pectin onto casein micelles. Biomacromolecules 3 (3), 632–638. Turgeon, S.L., Schmitt, C., Sanchez, C., 2007. Protein–polysaccharide complexes and coacervates. Curr. Opin. Colloid Interface Sci. 12 (4), 166–178. Ubbink, J., Mezzenga, R., 2006. Delivery of functionality in complex food systems: introduction. Trends Food Sci. Technol. 17 (5), 194–195. Valentova, H., Pokorný, J., 1998. Effect of edible oils and oil emulsions on the perception of basic tastes. Mol. Nutr. Food Res. 42 (06), 406–408. van Aken, G.A., Vingerhoeds, M.H., De Wijk, R.A., 2011. Textural perception of liquid emulsions: role of oil content, oil viscosity and emulsion viscosity. Food Hydrocoll. 25 (4), 789–796. van der Linden, E., 2012. From peptides and proteins to micro-structure mechanics and rheological properties of fibril systems. Food Hydrocoll. 26 (2), 421–426. Vanhoutte, B., Huyghebaert, A., 2003. Chemical properties of milk fat. In: Rossell, B. (Ed.), Oils and Fats, Volume 3—Dairy Fats. Leatherhead International Ltd, Leatherhead, UK, pp. 67–98. Veerman, C., Sagis, L.M., Heck, J., van der Linden, E., 2003. Mesostructure of fibrillar bovine serum albumin gels. Int. J. Biol. Macromol. 31 (4), 139–146. Villegas, B., Costell, E., 2007. Flow behaviour of inulin–milk beverages. Influence of inulin average chain length and of milk fat content. Int. Dairy J. 17 (7), 776–781. Villegas, B., Carbonell, I., Costell, E., 2007. Inulin milk beverages: sensory differences in thickness and creaminess using R-index analysis of the ranking data. J. Sens. Stud. 22 (4), 377–393. Wada, T., Sugatani, J., Terada, E., Ohguchi, M., Miwa, M., 2005. Physicochemical characterization and biological effects of inulin enzymatically synthesized from sucrose. J. Agric. Food Chem. 53 (4), 1246–1253. Walstra, P., 1990. On the stability of casein micelles 1. J. Dairy Sci. 73 (8), 1965–1979. Waugh, D.F., Creamer, L.K., Slattery, C.W., Dresdner, G.W., 1970. Core polymers of casein micelles. Biochemistry 9 (4), 786–795. WHO, 2017. http://www.who.int/mediacentre/factsheets/fs311/en/. (Accessed 15 November, 2017). Wu, J., Du, B., Li, J., Zhang, H., 2014. Influence of homogenisation and the degradation of stabilizer on the stability of acidified milk drinks stabilized by carboxymethylcellulose. LWT- Food Sci. Technol. 56 (2), 370–376. Yanes, M., Durán, L., Costell, E., 2002. Effect of hydrocolloid type and concentration on flow behaviour and sensory properties of milk beverages model systems. Food Hydrocoll. 16 (6), 605–611. Younes, I., Ghorbel-Bellaaj, O., Nasri, R., Chaabouni, M., Rinaudo, M., Nasri, M., 2012. Chitin and chitosan preparation from shrimp shells using optimized enzymatic deproteinization. Process Biochem. 47 (12), 2032–2039. Zegarska, Z., 2003. Milk lipids. In: Sikorski, Z.E., Kolakowska, A. (Eds.), Chemical and Functional Properties of Food Lipids. CRC Press, Boca Raton, FL, pp. 265–277. Zoppe, J.O., Venditti, R.A., Rojas, O.J., 2012. Pickering emulsions stabilized by cellulose nanocrystals grafted with thermo-responsive polymer brushes. J. Colloid Interface Sci. 369 (1), 202–209.

DAIRY-BASED FUNCTIONAL BEVERAGES

3

Deepak Mudgil, Sheweta Barak Department of Dairy & Food Technology, Mansinhbhai Institute of Dairy & Food Technology, Mehsana, India

3.1 Introduction Functional foods are the foods having certain functional or ­ ioactive components which are scientifically evidenced to have some b physiological functions in addition to its fundamental function of providing nutrition (Gibson and Williams, 2000). Globally, the functional foods market is a sun-shine segment of the food industry. Primary driving force for the growth of functional foods market is growing consumer interest toward the importance of nutrition in maintaining health (Fardet, 2015). In today’s world, consumers are more conscious toward their health and they want to increase good health via inclusion of functional foods in diet rather than spending money on medicines (Mudgil, 2017). Another driving force for the growth of functional foods market is increasing medical costs in last decade which has increased the interest of consumers toward functional foods. Also, the results of the scientific and medical studies of functional foods have validated the mechanism of action and adequacy of functional foods toward specific health conditions. All these factors are synergistically responsible for the rapid growth functional foods market (Champagne and Mollgaard, 2008). Globally, milk is consumed as a principal source of nutrients since ancient times (Erzen et  al., 2014). In Asian countries, milk is a part of daily diet and provides a major portion of RDA of nutrients such as protein, fat, vitamins, and minerals. Hence, milk is considered as an important source of calcium, fat, and protein (Mudgil et al., 2016). Milk is a colloidal system which consists of fat globules, lactose, proteins, vitamins, and minerals. The composition of milk is dependent on the breed of the animal. The composition of milk or the amount of different milk components can also be controlled by the feed of the animal. In milk, protein is the most significant component and its quantity as well as quality is influenced by certain factors of the cattle, Milk-based Beverages. https://doi.org/10.1016/B978-0-12-815504-2.00003-7 © 2019 Elsevier Inc. All rights reserved.

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i.e., ­physiological, nutritional, and genetic factors. Milk proteins comprise casein proteins, whey proteins, serum albumin, and immunoglobulins. Quantity of protein content in milk is dependent on breed, stage of lactation, as well as feed or nutrition. Breeds that produce milk with a high fat content also have higher protein concentrations (Walker et al., 2004). Modification or inclusion of range of lipid-rich supplements in the diet dairy cattle is most simple and effective way of manipulating the fatty-acid composition of milk. The amounts of changes that can be attained are influenced by type as well as source of lipid and basic diet (Givens and Shingfield, 2006). Milk-based beverages contain several components in addition to the basic components with beneficial physiological functions, such as peptides, oligosaccharides, enzymes, vitamins, and minerals. These components can be used as functional ingredient for the development of functional and nutraceutical food products with certain health benefits (Ozer and Kirmaci, 2010). Dairy milk contains many physiological, functional, and bioactive components which are situated inside the complex structures of milk components. These components remain unavailable commercially. These can be isolated or fractionated or concentrated from milk for which separation of dairy milk into skim milk and cream is carried out first. The cream portion contains all of the fat globules and associated components such as milk fat globule membrane, phospholipids, enzymes, membrane proteins, mucins, glycoproteins, etc. Bioactive components from milk contains whole proteins (such as β-lactoglobulin, α-lactalbumin, lactoferrin, and lactoperoxidase), hydrolyzed proteins (such as whey protein hydrolysates), and milk minerals. Bioactive ingredients from milk are classified as colostrum, glycomacropeptide or caseinomacropeptide, lactoferrin, lactoperoxidase, casein and whey protein hydrolysate, milk minerals, α-lactalbumin, etc. (Bhat and Bhat, 2011). The general definition describes the beverages as any liquid which are fit for human consumption and provide nutrition, refreshness, and appealing taste, and flavor. They may or may not have stimulating effect on us. Functional beverages provide certain health benefits in addition to one or all the above said functions (Playne et  al., 2003). Functionality of these beverages is due to the presence or fortification of certain bioactive or functional components. Dairy-based functional beverages can be classified in three major groups based on their main dairy ingredient, i.e., milk-based, whey-based, and buttermilk-based functional beverages. The base materials in these beverages are either liquid milk, or liquid whey (by-product of cheese/casein industry) or buttermilk (by-product of butter-making industry). Properties of milk components such as protein, lactose, and fat, minerals are very important in the development of milk-based beverages (Roy, 2008). Processing of these milk-based beverages affects the properties of final

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functional beverages. Whey-based beverages may be of acid, sweet, or fruit juice type. These may be fermented or unfermented, carbonated, or non‑carbonated. Processing of these whey-based beverages includes membrane processes, hydrolysis, and removal of lactose. Functionality of these whey-based beverages is mainly due to whey proteins (Holsinger et  al., 1974). Buttermilk-based functional beverages are prepared from the buttermilk obtained from butter processing or with fermented skim milk. Proteins and phospholipids present in buttermilk are the functional components having nutraceuticals properties (Conway et al., 2014). Bioactive or the functional components are the components in functional foods or beverages which have certain health benefits and are responsible for the functionality of functional foods or beverages (German et al., 2002). Processing operation such as homogenization, acidification, heating, etc. have certain effects on the milk components such as protein denaturation and protein coagulation, etc. Use of stabilizers or hydrocolloids in beverage making is essential as it prevents phase separation or sedimentation and creaming. Current health trend in beverage making involves development of low sugar, low fat, modified fat composition, modified protein composition, and fortified beverages. Several processing techniques can be utilized for increasing the shelf life of dairy-based functional beverages such as ultrahigh temperature (UHT) processing, high hydrostatic pressure (HHP) processing, pulse electric field (PEF) processing, pulsed light technology (PLT), use of antimicrobials, and membrane processing. Milk-based functional beverages can be classify into subclasses, i.e., low-calorie beverages, sports beverages, hyperimmune milk, probiotic beverages, fortified beverages, etc. (Paquin, 2009). Nowadays, milk and milk-based beverages are coming up all around the world including the natives which are nonconsumer of milk. These new consumers consume milk beverages due to the diversity in these beverages and their fortificants functional components. Milk remains among the significant source of nutritional components as well as functional components having physiological benefits. Future research in milk-based beverages will be focused on understanding the mechanism behind disease curing and prevention action of functional components of milk. These components will be commercially isolated and further food applications will be explored such as incorporation or fortification in various other food products and beverages. Future milk beverage developments are likely to include extensions of well-known brands (e.g., chocolates), flavored milks with artificial sweeteners, milk beverages with natural fruit purees, milk with bioactive components such as phytosterols, peptides, and antioxidants. As traditional beverage companies strive to differentiate their products, milk and milk ingredients may be blended with a range of traditional

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beverages, enabling beverage companies to capitalize on the nutritional and functional benefits of milk and milk-derived ingredients.

3.2  Bioactive Components in Milk Milk beverages contain several bioactive components such as β-lactoglobulin, α-lactalbumin, lactoferrin, lactoperoxidase, whey protein hydrolysates, vitamins, and minerals. Bioactive ingredients from milk are classified as lactoferrin, lactoperoxidase, lysozyme, glycomacropeptide or caseinomacropeptide, casein hydrolysates, whey protein hydrolysate, milk minerals, α-lactalbumin, galacto-oligosaccharide (GOS), conjugated linoleic acid (CLA), etc. (German et al., 2002). All these components have certain physiological functions and can be used for the development of functional foods and beverages.

3.2.1 Lactoferrin Lactoferrin is a globular glycoprotein with single peptide chain and molecular weight of about 77 kDa. It is a multifunctional protein belongs to transferrin family present in colostrum and milk in different proportions. Bioactivity of lactoferrin such as bacteriostatic effect, and enhanced iron absorption in the body is due to its iron-binding activity. One lactoferrin molecule can bind two atoms of iron. Lactoferrin protein exhibits antibacterial, antiviral, antioxidant, immune modulation, and iron transport and iron absorption function (Levay and Viljoen, 1995). Lactoferrin protein prevents the growth of pathogenic bacteria and fungi via binding of iron and making it unavailable for microbial growth. Lactoferrin protein also improves the efficiency of antibiotics via binding the outer membrane of Gram-negative bacteria and making the cell wall more permeable. It also acts as natural antioxidant and decreases the oxidative damage via scavenging the excess iron and stop the free-radical reaction (Mulder et al., 2008).

3.2.2 Lactoperoxidase Lactoperoxidase is an enzyme present in milk, whey, and colostrum. It has a molecular weight of about 77,500 Da. Lactoperoxidase is involved in the defense mechanism of host against bacteria which makes it biologically significant (Kussendrager and van Hooijdonk, 2000). It can be isolated from the whey on the principle that it remains positively charged at whey pH which makes it susceptible for linkage to ion-exchange resin. Lactoperoxidase is capable of inhibit the growth of wide range of microorganisms through an enzymatic reaction which involves H2O2 and thiocyanate ions as cofactors. These cofactors along with lactoperoxidase constitute the

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l­actoperoxidase (LP) system. Antimicrobial action of this LP system is based on the formation of hypothiocyanite ions via enzyme activation. Hypothiocyanite ions react with the bacterial membranes and also disrupt the functioning of certain metabolic enzymes. In some countries, H2O2 addition is not permitted hence in situ development of hydrogen peroxide is done via addition of glucose oxidase which is permitted. The source of thiocyanate ion can be either natural or added as sodium or potassium thiocyanate. LP system prevents the growth of Gram-positive bacteria and kills the Gram-negative bacteria (Seifu et al., 2005).

3.2.3 Lysozyme Lysozyme is a milk enzyme having antimicrobial activity. The concentration of lysozyme in colostrum and normal milk is about 0.14– 0.7 and 0.07–0.6 mg/L, respectively. Milk lysozyme is active against a number of Gram-positive and some Gram-negative bacteria. There seems to be a synergistic action of lysozyme and lactoferrin against many bacteria (Benkerroum, 2008).

3.2.4  Milk Minerals Major minerals essential for the growth and development of the bones and teeth are calcium and phosphorus. In today’s life, deficiency of calcium in diet is very common due to unhealthy eating habits. Recently, calcium fortification of several food products has been carried out as a result of awareness regarding calcium deficiency. Milk minerals are a good source of calcium which can be utilized for fortification of calcium food products and beverages (Cashman, 2006). Cheese or casein whey can be used for preparation of commercial milk mineral complex after removal of proteins and lactose from it. Commercial milk minerals are high in calcium and iron. It also contains 5% lactose and 5% protein content. Milk minerals (milk calcium complex) are manufactured from milk and whey. Calcium in milk minerals is present as calcium phosphate which is highly bioavailable in nature. Calcium in our diet is associated with osteoporosis and regulates the physiological functions such as cell function, conduction of nerve, contraction of muscle, and coagulation of blood. Calcium from milk minerals possesses certain bioactive functionalities such as osteoporosis prevention, bones and teeth growth, control of blood pressure and cardiovascular disease, hypertension lowering, colon cancer prevention, and obesity control (Gaucheron, 2005). Various food applications of milk minerals include development of nutritional and functional beverages, weight loss products, sports food products, and food supplements (as tablets and capsules).

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3.2.5 Glycomacropeptide Glycomacropeptide is water-soluble peptide of κ-casein which is essential for the stability of native casein micelles in milk. In cheese making, rennet acts on κ-casein and leads to the production of glycomacropeptide. It goes out with whey due to its water soluble nature. It can be separated commercially from whey via ion-exchange process because of having negative charge on it and whey proteins have positive charge at low pH (Rojas and Torres, 2013). Glycomacropeptide is a glycoprotein in nature and contain an oligosaccharide chain attached as side chain (Brody, 2000). Glycomacropeptide has its application in sports beverages/foods for muscle recovery after exhaustive exercise because of having good amount of branched-chain amino acids such as leucine, isoleucine, and valine. The absence of phenylalanine, tryptophan, or tyrosine also makes it unique for certain applications like in case of phenylketonuria patients. Part of population is suffering from phenylketonuria in which patients cannot digest phenylalanine. Glycomacropeptide is fit for those patients because they can tolerate it as it does not contain phenylalanine. Glycomacropeptide is also associated with several biological and physiological functions such as growth of bifidobacteria, decrease in gastric secretions, harmonization of immune system response, enterotoxins binding (Escherichia coli). Generally, it is considered beneficial for gut health, improves satiety, decreased dental caries, defense against diarrhea, anti-inflammation, binding of toxins, and intensified immunity. Glycomacropeptide is also reported to have potential for the treatment of colorectal cancer (Chen et al., 2013).

3.2.6  Milk Protein Hydrolysates Milk protein hydrolysates are prepared via enzymatic hydrolysis of milk protein and have applications in dietetic and medical foods (Mahmoud et  al., 1992). Preparation of milk protein hydrolysates is carried out to decrease allergenicity, increase adsorption, and improve functional properties of proteins for its end-use applications. These hydrolysates are also used in preparation of protein-enriched nutritious foods and beverages (Sinha et al., 2007). For enzymatic hydrolysis, milk proteins are dispersed in water and then the desirable pH and temperature is maintained at optimum value for the enzyme activity. The specific enzyme is then added to the substrate solution (protein) at a particular enzyme to protein ratio. In these specific conditions, enzyme hydrolyzes the peptide bond and allowed to continue the reaction till the desired degree of hydrolysis is achieved. The various unit operation involved in manufacture of milk protein hydrolysates are clarification, reduction of flavor, concentration/evaporation, spray drying, packaging, and storage. There is an important role of hydrolysis conditions in end product’s functional properties. Differentiation between d ­ ifferent

Chapter 3  Dairy-Based Functional Beverages   73

hydrolysates can be done by assessing the degree of hydrolysis. The main limitation of protein hydrolysates is their bitter taste which limits their food application. The number of hydrophobic amino acids is mainly responsible for the bitter taste of milk protein hydrolysate. Certain peptidases are capable of hydrolyzing the hydrophobic amino acids and hence they can be utilized as debittering agent. Milk protein hydrolysates have certain physiological functions such as decreased allergenicity, antigenicity, enhanced protein absorption, and bioactive peptides having certain physiological functions such as antihypertensive peptides for reduction in blood pressure which is related to the inhibition of the angiotensin-converting enzyme (McGregor and Poppitt, 2013). Milk protein hydrolysates are appropriate for the substitution of native proteins in infant and adult foods and beverages due to their decreased allergenicity. Antigenicity of protein is associated with its potential to instigate allergic reaction. Higher degree of hydrolysis in milk protein hydrolysates leads to lower antigenicity. Milk protein hydrolysates have high absorption as compared to native milk protein due to their peptide size. Hydrolysis of milk proteins also leads to release of bioactive peptide which is embedded in complex structure of protein molecule (Li-Chan, 2015).

3.2.7  α-Lactalbumin

α-Lactalbumin from dairy milk resembles with human milk which makes it fit for its utilization in preparation of infant foods having nearly similar amino acid composition. It is the second most abundant protein in whey with molecular weight of about 14 kDa. Commercially, α-lactalbumin can be isolated from cheese whey using ion-exchange technology or acid precipitation or ultrafiltration (UF) for manufacturing ingredients containing high amount of α-lactalbumin. It is reported to be a good source of tryptophan for the synthesis of the neurotransmitter serotonin (Kamau et  al., 2010). In United States, tryptophan-rich α-lactalbumin is being produced by Davisco Foods which is considered to be associated with sleep improvement and enhanced alertness (Markus et al., 2005). α-Lactalbumin also described to possess anti-carcinogenic activity. It has been exhibit to reduce the cell division and persuade apoptosis in cancer cell lines of mammals. Recently, it has been used as a carrier for vitamin D enrichment in food products (Delavari et al., 2015).

3.2.8 Osteopontin Osteopontin is an acidic glycoprotein and is highly phosphorylated. Osteopontin possess strong calcium-binding properties. Much has not been known about this protein hence research is being carried out to

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find its role in physiological functions. Preliminary studies on osteopontin reveal that it is associated with the development of immune function in infants (Rittling and Singh, 2015.). Infant foods containing osteopontin helps in attaining harmonization of immune system in non-breastfed infants as compared to the infant who are on breast feeding. Osteopontin protein was identified in breast milk just after it was discovered in human body. It is commercially available from Arla Foods for infant nutrition.

3.2.9 Galacto-Oligosaccharide GOSs are mixture of substances produced from lactose or lactulose composed of 3–8 molecules of galactose and glucose. Glucose is present at terminal position and remaining saccharide and disaccharide comprised of two galactose units (Mahoney, 1998.). GOSs are nondigestible in nature and are established as prebiotic ingredient as they enhance the growth and number of beneficial bacteria such as Bifidobacteria, Lactobacillus, etc. and decrease the growth and number of harmful bacteria such as Clostridia, Enterobacter, etc. GOSs are beneficial to host because the role of beneficial bacteria in gut health has already been proved. Its role in immune function is indicated by remarkable increase in phagocytosis, NK cell activity, production of anti-inflammatory cytokine interleukin-10, remarkable reduction in the production of pro-inflammatory cytokines and recovery of innate immune cells in the elderly persons for the enhancement of gastrointestinal health and immune function in elderly persons. Stable gut microflora also play an important role in metabolic as well as in overall health. There has also been increasing affirmations of its benefits in mental health and well-being. It has also been reported to offer ­anti-anxiety benefits. It is also associated with colorectal cancer (Bruno-Barcena and Azcarate-Peril, 2015). Some studies involving children showed improvement in stool consistency, reduced permeability of intestine, decreased occurrence of GI tract and respiratory tract infections, and atopic dermatitis.

3.2.10 Conjugated Linoleic Acid CLA isomers are naturally found in milk and milk products. They are heterogeneous group of isomers of linoleic acid classified under the family of polyunsaturated fatty acids. cis9, trans11-CLA and trans10, cis12-CLA isomers of linoleic acid are considered to be biologically active or functional isomers (Kee et al., 2010). These biologically active isomers are beneficial in various disease conditions such as cancer, diabetes, obesity, and atherosclerosis. Milk fat is reported to have the highest amount of CLA, i.e., 2–53.7 mg/g fat (Collomb et al., 2006). In milk fat, c9, t11-CLA is present in higher amount (i.e.,  ­75%–90%

Chapter 3  Dairy-Based Functional Beverages   75

of ­total CLA) than t10, c12-CLA which is present in minor quantity. The molecular mechanism of CLA depends predominantly on the CLA-mediated biochemical pathways. Anticancer activity of CLA may be due to its role in inhibiting DNA synthesis as well as in inhibiting angiogenesis reducing eicosanoids production. CLA supplementation in diet is also associated with the management of type II diabetes. Some of its isomers have antidiabetic effect. c9, t11-CLA isomers are very effective in insulin resistance of obese. CLA isomers are also beneficial in atherosclerosis via mechanisms such as increased HDL, reduction of vascular inflammation, and over expression of HDL receptors. CLA is beneficial in body fat reduction via mechanisms such as ­enhancement of energy disbursement, attenuation of adipokines and cytokines, reduction of lipid assembled in adipose tissues, and or adipocytes differentiation. Dietary CLA is also associated with increased bone formation rate. CLAs are also reported to have antioxidant activity (Silva et al., 2014).

3.3 Classification 3.3.1  Milk-Based Functional Beverages Milk-based drinks or beverages are consumed since ancient times. Initially the full-cream milk was consumed by all (infants, adults, and aged) but with introduction of technologies like pasteurization, sterilization, homogenization, and centrifugation or separation, special types of milk or milk-based beverages are manufactured for specific target groups, e.g., skim milk or toned milk for the persons who are obese and having diseases related to fat consumption. In last decade, a trend of healthy fortified drinks came into practice. The fortificants used in these beverages are bioactive or functional in nature and have been associated with certain physiological benefits. Various fortificants added in these beverages are prebiotic, probiotic, dietary fiber, phytosterols, MUFA, PUFA, proteins, minerals, vitamins, etc. Milkbased beverages are generally the beverages in which liquid milk or skim milk powder (SMP) is main ingredient. The main ingredients used in manufacturing of these beverages are skim milk or SMP, sugar, preservatives, colors, flavors, acids, functional ingredients, fruit mixes/ juices/concentrates, and water. The milk-based beverages segment is among the important segment in dairy market. This segment has been considered as the fastest growing segment with variety of products means new beverages are coming into market very frequently in this segment. The major innovations involved in dairy-based beverages are variety of functional or bioactive components and the packaging section. The viscosity of milk-based beverages is generally high and pH is generally low as compared to liquid milk. Major processing steps

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involved in milk-based beverages are homogenization, heat treatment, acidification, enzymatic processing, stabilization, etc. All these steps are necessary for the optimal desired quality of final beverage.

3.3.1.1 Homogenization Homogenization is the most important and fundamental unit operation involved in the processing of milk beverages. Basically it deals with the reduction of fat globules or droplets size to improve the mouthfeel or textural quality of milk beverage. In this operation, the milk before or after addition of other ingredients is passed through a narrow aperture with high shear by application of pressure which results in reduction of fat droplets size or protein particle size. Homogenization is generally used to emulsify fats (McCrae, 1994) and to reduce protein particle size (Anema et al., 2005). Homogenization is must for acidified milk-based beverages. It is also necessary when protein portion is replaced with plant protein. If unhomogenized milk is used for the preparation of functional milk beverage then textural defects such as sedimentation, powderiness, creaming is likely to be observed in final beverage.

3.3.1.2 Acidification Acidification is a significant processing operation as it deals with increase taste, viscosity, and shelf life of the beverage. Acidification is carried out to decrease the milk beverage pH to 3.6–4.6 as compared to natural milk pH (6.6–6.8). At the isoelectric point of protein, the net charge on protein molecule is zero which leads to reduction in the repulsive forces between molecules and ultimately increases the mutual attraction between the molecules. In casein micelles, the charge neutralization at isoelectric point causes disruption of the hairy layer structure on the surface of the micelles (Horne, 1998). This disruption leads to reduction the colloidal stability of the protein suspension and causes aggregation and increase in viscosity of the suspension. Acidification can be attained via chemical (glucono-delta-­lactone) acidification (Banon and Hardy, 1992) or bacterial (lactic acid bacteria) acidification (Folkenberg and Martens, 2003). Bacterial acidification is generally carried out using lactic acid bacteria which acts on lactose and convert it into lactic acid. It also produces certain compounds such as acetaldehyde and diacetyl responsible for flavor. Laboratory-scale chemical acidification can be carried out using ­glucono-delta-lactone and pressurized CO2. Commercial chemical acidification can be carried out using lactic, citric, malic, and phosphoric acid. In chemical acidification resulted aggregates are very compact hence it should be followed by homogenization process. Acidification process is generally followed by mixing with fruit pulp or

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fruit juices and vigorous s­ tirring is carried out to maintain the liquid nature of final beverage and enhances its mouthfeel and stability.

3.3.1.3  Heat Treatment Heating operation in beverage making is carried out to inactivate microorganisms (mainly bacteria) and enzymes. Heating process is significantly associated with shelf life of functional milk beverages. Inactivation of vegetative microorganisms can be achieved via pasteurization which is normally carried out at 72–75°C for 15–20 s. Inactivation of most resistant bacteria spores can be achieved via UHT sterilization which is normally carried out at 135–150°C for few seconds. Inactivation of all enzymes is not acquired after sterilization and requires very exhaustive heating treatment. Most of the enzymes are present at interface of fat globules of milk that is the reason behind lesser enzymes in skimmed milk. Some enzymes like plasmins are reported have some role in defect (age gelation) in UHT milk (Datta and Deeth, 2001). Heating of milk also causes denaturation of whey proteins at temperature higher than 70°C which leads to binding of whey proteins with each other as well as with casein micelles by virtue of hydrophobic and disulfide interactions. These interactions are responsible for low stability of UHT beverages during storage. Heating operation is also associated with changes in casein micelles. At neutral pH, a very high temperature causes solubilization of kappa-casein in serum which causes aggregation of micelles (partly reversible) also known as heat coagulation. This effect is more pronounced at lower pH and can cause permanent instability. Heating operation causes chemical changes along with physical changes in milk beverages. The most important example of this is cooked flavor which originates from sulfhydryls groups. If sufficient quantity of oxygen is available, this cooked flavor decreases during storage. Sterilized cooked flavor develops at temperature above 90°C and possibly due to reaction between proteins and sugars (Maillard reaction). Sterilized cooked flavor in UHT milk beverage is assisted by browning reaction.

3.3.1.4  Role of Enzymes Enzymes can also be utilized as processing aids in beverage processing but it is still to be explored. Enzymatically hydrolyzed proteins can be used in functional milk beverage formulations for better texture and digestibility (Korhonen, 2009).

3.3.1.5  Role of Stabilizers Inclusion of hydrocolloids in beverage formulation is desirable from stability and viscosity point of view (Mudgil et  al., 2011). Hydrocolloids are stabilizing polymers from plant (e.g., guar gum,

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locust bean gum) or microbial sources (e.g., xanthan gum) (Mudgil et al., 2014). These hydrocolloids are also known as thickener because of its high viscosity in aqueous systems (Mudgil et al., 2012; Barak and Mudgil, 2014). Hydrocolloids reduce sedimentation and or creaming upon storage in milk-based functional beverages. The use of hydrocolloids along homogenization and proper hydration of proteins contribute to more efficient stabilization, which is not achieved singly by homogenization. The mechanism of action of hydrocolloids in functional milk beverage making involves viscosity action, gelling action, and complex formation. All the mechanisms lead to less sedimentation, separation, creaming, and more stability of milk beverage during storage conditions. Viscosifying hydrocolloids include guar gum, locust bean gum, starch, etc. Gelling hydrocolloids include agar, low-methoxy pectin, alginate, xanthan gum, etc. Complexing hydrocolloids include high-methoxy pectin and carrageenan.

3.3.1.6  Low-Sugar Functional Milk Beverage Low-sugar functional milk beverages can be prepared by sugar replacement with fruit sugar or by enhancing the milk sugar in the beverages. Sugar reduction in milk beverages can also be achieved by sugar replacement with artificial sweetener having high relative sweetness (Kroger et al., 2006). Apart from the addition of artificial sweeteners, enzymes can also be used in increasing the sweetness of milk beverages, e.g., lactase enzyme can hydrolyze lactose into glucose and galactose which is also suitable for lactose-intolerant persons.

3.3.1.7  Low-Fat Functional Milk Beverage Most of the milk-based beverages are relatively high in fat (i.e., 3%–5%). This amount of fat is considerably high for the people who are having certain disease condition such as heart disease. Hence reduction in fat content of these beverages is essential for health purpose. This is the reason why toned and double-toned milk used in the processing of these beverages. There is a difference in taste profile and mouthfeel of full-cream and toned milk. However, the taste and consistency of skim milk is not desirable as it is more watery and transparent as compared to full-cream milk. To overcome this problem, manufacturers are adding hydrocolloids and thickeners (such as modified starches) to get the same consistency (Villegas et al., 2010).

3.3.1.8  Functional Milk Beverage With Altered Fat Composition In general, it is considered that there should be fewer amounts of saturated fatty acids and trans fatty acids in our diet because these are negatively associated with our health. It can be reduced by reducing the whole fat content of the beverage means low-fat beverage. Another way

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of reducing these fats is the substitution of these fats with certain health benefits. The fat which are high in unsaturated fatty acids (e.g., vegetable and marine oil) are considered good for substitution due to their certain health benefits (Ward and Singh, 2005). Problem associated with these oils is that they are more prone to oxidation and lead to off-flavor. Hence, some changes in processing and packaging of the beverages are carried out to avoid oxidation, i.e., addition of antioxidants and sequestrants, minimum head space, reduced transparency of the pack. Fatty acids of current interest in functional beverages are CLA, EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid) due to their role in various physiological functions and disease prevention (Kolanowski and Laufenberg, 2006).

3.3.1.9  Functional Milk Beverage With Altered Protein Composition Native dairy proteins can be altered for enhanced functionality or nutrition purpose, e.g., caseinate (non-micellar protein) which is used for improvement emulsifying action. Protein hydrolysis via enzymatic treatment is also an option for the modification of protein composition (Sinha et al., 2007). Nondairy protein sources can be used for altering the milk protein composition. Rice, oat, and soya milk are the products often found in super market shelves (Makinen et al., 2016). This segment of dairy will grow in near future including the locally available sources of vegetable protein. Beverages containing vegetable proteins have some undesirable off-taste which is due to the activity of inherent enzymes present in tissues. This defect leads to low acceptability of these beverages from consumer point of view.

3.3.1.10  Fortification of Beverages Functionality of a beverage can be increased via addition or fortification of new ingredient rather than altering the fat and protein composition. In last decades, several fortified food products as well as fortified beverages are introduced in the market. This segment of the industry has opportunity for the future functional beverages based on milk or dairy ingredient. Various fortificants that can be used for the development of functional milk beverages are CLA, EPA, DHA, probiotics, prebiotics, dietary fiber, vitamins, minerals, polyphenols, phytosterols, etc. (Ghasempour et al., 2012; Mudgil et al., 2016; Mudgil and Barak, 2016; Shree et al., 2017). Vitamin fortification is considered as the oldest method of fortification. Water soluble vitamins can be fortified in beverages without disturbing the physicochemical properties of the beverages however their oxidative nature is little problematic. Oxidation of vitamin during storage of beverage can cause reduction in its concentration, undesirable taste, and color changes in

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the beverage. Vitamin fortification is generally carried out in milk and fruit-mixed beverages. Milk-based beverages are considered to be an excellent vehicle for the delivery of mineral hence mineral fortification in milk beverages is commonly practiced. The addition of minerals such as calcium or iron is also a relatively common. Both soluble and insoluble mineral salts are available for fortification of milk beverages. Soluble form of mineral has good bioavailability but undesirable taste. The insoluble form of minerals has good taste but occasionally causes sedimentation. Some mineral ions are also associated with oxidation reactions. Polyphenols from vegetable sources have attracted interest during last decade. These are associated with good heart health hence they can be used for the fortification of dairy beverages. Polyphenols generally react with proteins to form an ionic complex which leads to product instability. Fiber fortification in milk beverages is a recent topic of interest but only soluble fiber can be used in beverages. Fiber fortification also leads to some textural changes in beverages due to its viscosity property hence it should be used at a concentration at which they do not affect textural property. Prebiotics are nondigestible carbohydrate that act as food for the gut bacteria and enhances growth of these bacteria in the colon. Phytosterols can also be used as fortificants in milk beverages as these are associated with reduction in blood cholesterol levels (Ozer and Kirmaci, 2010).

3.3.2  Whey-Based Functional Beverages Whey is a by-product obtained from cheese or casein processing (Prazeres et al., 2012). Its composition mainly depends on the quality of milk taken, type of processing, and main product manufactured. The liquid whey obtained as a by-product contains about 93% water and about half of the total solid content present in native milk used for cheese or casein processing. Lactose is major component of the total solids in whey. There are two types of whey, i.e., sweet whey and acid whey depending on the type of processing involved for the main product. In last decade, whey has been extensively studied for its nutritional and functional properties which revealed that it is an extremely important component having certain functional and nutritional elements such as immunoglobulins, lactoferrin, lactoperoxidase, and certain growth factors. Due to these reasons, processing of whey into beverages comes in practice. The two main objectives of whey beverage making are utilization of large volume of whey to solve disposal problems and development of functional beverages which are having certain health benefits. The utilization of whey for beverage making is one of the best examples of value addition (Sabokbar and Khodaiyan, 2015). Whey proteins are easily digestible hence whey proteins as such or their hydrolysates are used for the development of

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functional ­beverages for elderly people. Functional beverages formulated with whey are also nutritionally important for sportspersons (for stamina) and bodybuilders (for muscles growth and development). The functionality of whey-based beverages can also be enhanced via incorporation of bioactive and functional ingredients such as probiotics, dietary fiber, vitamins, minerals, etc. (Smithers, 2015).

3.3.2.1  Types of Functional Whey Beverages Whey-based functional beverages are broadly divided into main four categories depending on use of other ingredients and processing operation for manufacture of the beverage. Different classification on the basis of target group of the beverages can also be made. The main four categories of functional whey beverages are fruit juice based, dairy based and thirst quenching type. Fruit Juice Based Fruit juice and pulp mixed with whey (with or without deproteinization) are widely used for the development of functional wheyfruit beverage. These types of beverages have potential to replace the fruit juice-based morning beverages and health beverages due to having nutritional significant additional nutrients (Sabokbar and Khodaiyan, 2015). The main ingredients used in these beverages include whey, fruit juice/pulp/concentrate, flavor, color, sweetener, and preservatives. Flavor and color used in these beverages should be associated with the type of fruit juice or concentrate. Acid whey is generally utilized for making these beverages. Mineral and vitamin fortification of fruit-whey-based beverages makes them fits for sportspersons. Manufacture of these beverages generally involves unit operations such blending of juice and whey, heat treatment, and packaging. Sedimentation during storage due to denaturation of whey proteins on heating is one of the prominent defects in these beverages. This sedimentation defect can be diminished by adjusting the pH (around 3.6) of the beverage before heating treatment. At even this low pH, some sedimentation is observed which is related to the interaction between whey proteins and pectin from fruit pulp or juice. This can be prevented by using fruit sources having very low amount of pectins or via enzyme treatment of fruit juice before blending with whey. Dairy Based Whey or whey components can be utilized as functional component for the development of dairy-based beverage such as liquid yogurt. In this type of beverages whey constitute a portion rather than as the main ingredient. These types of beverages can be classified

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into two categories—fermented- and non-fermented-type beverages. Fermented-type beverage include cultured dairy beverage such as butter milk, sour milk, etc. Non-fermented-type beverages include milk smoothes, flavored milk, etc. Both types of the beverages contain a significant quantity of whey or portion of whey. Sweet whey is used for the development of non-fermented-type dairy beverages whereas acid whey is used for the development of fermented-type dairy beverages. In fermented-type dairy beverage, the pH is low and casein has tendency to get precipitated at pH 4.6. This can be avoided via stabilizing the beverages with addition of hydrocolloids which stabilizes casein and do not allow it to precipitate. Hence addition of hydrocolloids in fermented-type dairy-based whey beverages is very significant from physical quality point of view. Also heating of beverages also associated with denaturation and insolubility of whey proteins hence nonthermal processing of these beverages can be carried out to solve this technical problem. Whey protein isolates and whey protein concentrates can also be used for the protein enrichment of these types of beverages (Ozer and Kirmaci, 2010). Thirst Quenching-Type Beverages Carbonated-type beverages are generally included in thirst quenching beverage category. Major ingredient in carbonated beverages is water and the minor ingredients include sweetener, color, flavor, and carbon dioxide. In these type of beverages, water portion is generally replaced by clarified and deproteinated liquid whey. Without deproteinization, carbonation of these beverages becomes difficult because of foaming property of whey protein (Jelen, 1973). The functional behavior of these beverages is not due to whey proteins but due to further addition of vitamins, minerals, and other functional fortificants make them functional beverages.

3.3.2.2 Processing Membrane Processing and Demineralization UF plays a crucial role in the manufacturing of functional wheybased beverages. UF is capable in separation and concentration of soluble whey proteins (Galanakis, 2015). UF retentate can be used as the base material for some of the whey-based beverages. Dried powder of UF retentate can also be prepared for further used as ingredient in beverages or can be dried for later use as an ingredient or after reconstitution as the primary liquid component. UF permeate can also be used as ingredients for beverages (thirst quenching) as it contains water-soluble lactose and minerals. UF processing of skim milk is generally used for the manufacture of soft cheeses which results in a UF permeate having chemical composition identical to that of the whey

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UF permeate which can be further used as potential ingredient for manufacturing thirst-quenching beverages. Fermentation Process Whey contains appreciable amount of lactose which can be fermented by lactic acid bacteria. This lactose component makes the whey fit for the preparation of fermented beverages. Sweet whey is generally utilized for fermentation purpose. The fermentation process via specific strains of bacteria makes the whey beverage more functional because of production of bioactive peptides during fermentation (Brandelli et al., 2015). Whey can also be utilized in drinkable yogurt which is fermented products of dairy milk. Whey can replace the milk portion in these beverages. Fermentation of whey and whey components has also been studied using kefir grains and reported to be an attainable process for commercial preparation (Sabokbar and Khodaiyan, 2015). Lactose Hydrolysis and Removal Lactose hydrolysis and or removal from whey are very important for lactose intolerant people. Lactose intolerant people cannot digest lactose hence it should be hydrolyzed or removed from the whey for the development of functional beverages that can also be consumed by lactose intolerant people. Lactose hydrolysis can be achieved via enzymatic process using immobilized or soluble enzyme which hydrolyze it in glucose and galactose (Das et al., 2015). Immobilized enzyme can be recovered after the hydrolysis and can be used for further hydrolysis of new batch. Other methods for lactose hydrolysis include acid-catalyzed hydrolysis at high temperature. Hydrolysis of lactose is also required to increase the sweetness in the beverage which can overcome the acidity. Lactose removal is generally carried out to prepare lactose-free milk. Chromatographic processes and crystallization processes are used for the removal of lactose from the whey.

3.3.3  Buttermilk-Based Functional Beverages Buttermilk is produced during manufacturing of dairy butter as by-product. Buttermilk is similar in composition to skim milk except of having high levels of phospholipids due to the presence of milk fat globule membrane which is separated from fat globule during butter making. Milk fat globule membrane is recovered in buttermilk along with proteins and water soluble lactose and minerals. Buttermilk has great ability for development of functional beverages due to the presence of protein, phospholipids, and minerals which are helpful in prevention of diseases such as heart diseases, diabetes, cancer, etc. (Mudgil et al., 2016). Sphingomyelin is reported to have a preventive

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role in colon cancer. Sphingolipids are also reported to be associated with reduction in cholesterol levels. The main functionality of liquid buttermilk and powdered buttermilk in functional food and beverages is associated with remarkable buffering and antioxidant activity. The phospholipids content of buttermilk has a growth preventive effect on some pathogens. Earlier buttermilk was used in dairy plant for standardization purpose. Presently, fermented skim milk is used to prepare dairy-based beverage which is similar to buttermilk produced during butter manufacture. This fermented skim milk is known as cultured buttermilk. There has been observed increasing interest in formulation of beverages using buttermilk. Buttermilk can be used an ingredient for the formulation of functional beverages. It is reported that buttermilk along with soy protein isolate can be used for preparation of functional beverages. Functional dairy beverage based on buttermilk, fruit juices, fruit pulps, and certain additives having similar protein content compared to milk can be prepared with desirable sensory quality (Shree et al., 2017). Cultured buttermilk can be used as a vehicle for the delivery of functional or bioactive ingredients such as dietary fiber, prebiotics, probiotics, fruits-based functional, bioactive peptides, etc. Fortification of cultured buttermilk with dietary fiber has been reported in the literature. Cultured buttermilk was prepared with and without fortification of partially hydrolyzed guar gum as dietary fiber source. It is also reported that fortification of soluble dietary fiber also improves physicochemical and sensory properties of cultured buttermilk. Partially hydrolyzed guar gum as soluble dietary fiber is beneficial in the diseases like heart diseases, diabetes, and digestion-related diseases (Mudgil and Barak, 2016). Aloe vera juice fortification in cultured buttermilk is also reported in the literature in which cultured buttermilk is fortified with A. vera juice for the development of functional buttermilk beverage. A. vera juice and gel has been utilized for its nutraceutical properties since old times. A. vera juice is rich in various bioactive components such as acemannan, glycoprotein, anthraquinones, steroids, antioxidants, vitamins, minerals, etc. Similar to milk, buttermilk is also deficient in dietary fiber, iron, and vitamin C. A. vera juice fortification in cultured buttermilk makes the buttermilk complete on nutrient profile and functional in nature due to the presence of several bioactive components (Mudgil et  al., 2016). Buttermilk as well as buttermilk solids favors the growth of probiotic bacteria hence these can be used for the development functional buttermilk with added probiotics which are essential for the gut health. Nowadays, probiotics are current topic of research interest among food scientists and food microbiologists (Ghasempour et  al., 2012). Prebiotics can also be added in cultured buttermilk for the development of functional beverages. Prebiotics are

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the indigestible carbohydrates which act as food for the beneficial gut bacteria. Prebiotics promote the growth and activity of the gut bacteria and resulted in improved gut health. Buttermilk can also be fermented and dried to obtain peptide-enriched powder which can be utilized for the development of functional beverages. Hence, buttermilk from butter making and cultured buttermilk from specialized processing have potential to be used for the development of functional beverages having certain health benefits in disease prevention.

3.4 Properties Certain physicochemical properties are required to be maintained during storage of functional beverages. It is very important from consumer point of view. The main physicochemical properties of functional beverages are as follow.

3.4.1  pH and Acidity pH and acidity of beverages are of great importance during processing and storage (Mudgil et al., 2016). pH of beverage is directly related with the molecular and structural stability of other ingredients used in beverage formulation. Low pH and high acidity leads to casein and whey insolubility which causes sedimentation defect in beverages. These are very crucial to control in the fermented type of functional dairy beverages.

3.4.2 Viscosity Viscosity is considered as a measure of resistance toward flow of the beverages. Viscosity property is directly associated with the sensory properties such as mouthfeel and consistency (Mudgil et  al., 2016). If viscosity is too low it gives the feeling of watery texture of the beverage and if viscosity is too high it reduces the liquid behavior of the beverage. Hence, viscosity is desired at certain optimum level which enhances the sensory quality of the beverage. Optimum value of viscosity is also associated with high-phase stability during storage of beverage. Certain hydrocolloids used in beverage processing are responsible for viscosity property in beverages.

3.4.3  Dispersibility of Ingredients Ingredients used in beverage manufacture should have high water solubility and dispersibility. The use of stabilizers and emulsifiers aids in ease of dispersibility of ingredients in beverages. pH of the beverage also play a significant role in the solubility and dispersibility

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of ingredients in beverage. Low solubility and dispersibility is directly associated with phase stability of beverages during storage.

3.4.4 Color Stability Color of the beverage is the most important parameter from consumer point of view. Color of the beverage should be consistent throughout the storage period. Any change in color of beverage with storage leads to unacceptability of the beverage. Hence colorant used for the beverage should be compatible with the other ingredients of the beverage. Interaction between the ingredients and changes in pH conditions leads to discoloration reactions. Sometimes color stabilizers are recommended to preserve the color of the beverage during storage conditions.

3.4.5  Flavor Stability Flavor of the beverages are very important aspect from consumers point of view. Flavor of the beverages should be stable throughout the storage period for better acceptability. Bioactive or functional ingredients used in functional beverage formulations sometimes have obnoxious or unpalatable taste. Masking agents are sometimes effective in masking this unpalatable taste.

3.4.6  Phase Separation or Storage Stability Separation of aqueous phase on the top surface of the beverage is known as phase separation. It is a defect and not acceptable by consumers. This phenomenon is associated with storage stability of the beverage (Mudgil et  al., 2016). High storage stability is desirable for beverages for acceptability point of view. Storage stability of the beverage is interrupted when the ingredients in the beverages interact with each other. Hence the selection of ingredient for beverage formulation is very crucial to preserve the original rectitude of the ingredients during storage period. While analyzing the storage stability, the tentative conditions of transportation and storage should be considered. The accelerated storage stability tests are carried out to predict the storage stability.

3.5  Health Benefits Milk is an essential part of the daily diet of people all around the globe. Functional dairy-based beverages are exceedingly being consumed by people of all age groups. The functional dairy beverages include milk fortified with probiotics, prebiotics, phytosterols,

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a­ ntioxidant, bioactive peptides from milk, dietary fiber, minerals, vitamins, and colostral immunoglobulins. The above-mentioned bioactive components have been found to exert profound effect on the overall health of individual (Ozer and Kirmaci, 2010). The addition of probiotics to the milk has seen a growing trend in the last few years. The addition of probiotic microorganism to milk helps in maintaining good intestinal microflora. Scientific studies have demonstrated a number of health benefits associated with the consumption of probiotic milk beverages. These include lowering the cholesterol levels in body, alleviation of lactose intolerance symptoms, prevention of intestinal tract infections, prevention of diarrhea, prevention of colon cancer, and improvement of immunity. The selection of probiotic strains, optimization of the dose level, the manufacturing conditions have known to have a profound effect on the functionality of beverage. Moreover, prebiotics along with probiotics are increasingly being used to produce a symbiotic dairy beverage which offers many health benefits. The most common prebiotics are inulin, fructo-oligosaccharides (FOSs) and GOSs. The prebiotics supports the growth of probiotics and thus help in improving individual’s health (Bruno-Barcena and Azcarate-Peril, 2015). Colostrum is often regarded as the first milk produced by a cow after the birth of the calf. Colostrum has a high concentration of immune and growth factors which are essential for the health of the newborn. Colostrum contains approximately more than 10 times the immunoglobulins present in normal milk. Colostrum is rich in growth factors which regulate a variety of cellular functions and tissue repair and growth. It also includes several other bioactive components such as lactoperoxidase, lactoferrin, and lysozyme (Zou et al., 2015). Lactoperoxidase is active against the microorganisms and causes their destruction. Lactoferrin binds large quantity of iron and thus inhibit the growth of microorganisms. It also has antioxidant properties and thus retards the ageing process. Thus, the addition of various colostrum components to the milk helps to improve the immunity, prevent diarrhea, provide protection against infections, and prevent stomach cancer and ulcers. Phytosterols, also referred to as phytosteroids, are naturally occurring compounds obtained from plant cell membranes. They are chemically and structurally similar to cholesterol. They are found in significant quantities in fruits, vegetables, vegetable oils, nuts, grains, and seeds. In most cases, the chief components are campesterol βsitosterol, and stigmasterol. Phytosterols are known to reduce the absorption of cholesterol from the gut, thereby, lowering the low-­density lipoprotein cholesterol levels in the body. Phytosterols displace cholesterol from intestinal micelles, reducing the amount of absorbable cholesterol. Phytosterol esters dissolved in food fat reduce LDL

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c­ holesterol by 10% at a maximum effective dose of 2 g/day (Ostlund, 2004). Low LDL cholesterol and high HDL cholesterols help to maintain a healthy heart. Nowadays, phytosterols are well recognized as cholesterol-lowering agents for the primary and secondary prevention of cardiovascular diseases. Moreover, the American Heart Association and the European Current Dietary Guidelines recommend phytosterols as a therapeutic option for the treatment of patients with elevated blood cholesterol (Lichtenstein et al., 2006). In the recent years the trend of addition of beneficial omega fatty acids to the food products has been observed. In particular, omega-3 fatty acids are added to dairy products to improve its functional properties. Omega-3 fatty acids include EPA and DHA, and ALA (α linolenic acid). Omega-3 fatty acids have an array of health benefits such as prevention of cardiovascular diseases, abnormal clotting of blood, lower body triglyceride levels, possess immune-­modulatory effect, and promote brain development and functioning. The sources of omega-3 fatty acids are canola oil, flaxseed oil, fish oil, and algae. The main constraint while the addition of omega-3 fatty acids to milk remains their strong odor and poor oxidative stability (Ward and Singh, 2005). The fortification of dietary fiber in milk drinks will lower the risk of diabetes, improve the digestive system, prevent hemorrhoids and diverticulosis, reduce body weight, and prevent the occurrence of coronary heart diseases. The different sources of dietary fiber are fruits, vegetables, whole grains, and legumes. Dietary fiber is of two types— soluble and insoluble dietary fiber. The soluble dietary fiber binds the fatty acids and prolongs the stomach emptying time, thereby lowering the cholesterol levels and preventing high blood glucose levels. On the other hand, insoluble dietary fiber is not absorbed and adds to the bulk and maintains the pH in the intestine. Thus it promotes regular bowel movements and prevents constipation, removes the toxic waste through colon in less time, and prevents colon cancer by keeping an optimal pH in the intestine to prevent microbes from producing cancerous substances. The American Dietetic Association recommends a daily dose of 20–35 g of dietary fiber for adults (Mudgil and Barak, 2013). Antioxidants are the substances which protect the cells from damage caused by harmful molecules called free radicals. The oxidative processes in our body produce highly reactive compounds called free radicals or these may also enter our body from the environment. Antioxidants are the compounds which inactivate the free radicals and prevent the oxidative stress which may damage or kill the DNA cells (Jiang and Xiong, 2016). Antioxidants are found in fruits and vegetables and include vitamin C, vitamin E, vitamin A, as well as enzymes such as catalase, glutathione peroxidase, glutathione reductase, and

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superoxide dismutase. Antioxidants have shown to prevent a number of diseases such as cancer, coronary heart disease, delay ageing, boost the body’s immune system, neurological disorders, and neurodegenerative diseases. Daily intake of several minerals is important for the basic function of the human body. The minerals such as calcium, iron, copper, magnesium, manganese, and zinc are necessary for proper functioning and growth of human body. Milk is considered as a good medium for the delivery of the essential minerals into our body. The milk itself is a very good source of calcium which is required to maintain healthy bones and teeth. Apart from calcium copper is required by the body for normal growth and health, especially in the formation of red blood cells. It is also necessary for the functioning of the heart and arteries, prevention of bone defects such as osteoporosis and osteoarthritis (due to its anti-inflammatory property). It also promotes healthy connective tissues such as nails, hairs (vital component of melanin), and blood vessels. Good food sources of copper include vegetables, legumes, nuts, seeds, mushrooms, avocado, and whole grains. Another important mineral for the body is iron. It is an essential component of hemoglobin and myoglobin prevents anemia, helps in synthesis of hormones and connective tissue in the body. Magnesium is an important mineral for the activation of number of enzymes in our body. It is necessary for protein synthesis, regulation of blood pressure, control of blood sugar and for the normal functioning of muscle and nerves. Manganese, though required in traces, is vital for the activation of enzymes (particularly those involved in digestion), for growth of bones and reproduction. Another trace mineral, zinc, is required for cellular metabolism, immune function, synthesis of proteins, DNA synthesis, and wound healing. Thus, the fortification of the above essential minerals to milk improves its functionality (Ozer and Kirmaci, 2010). The fortification of milk with different vitamins especially vitamin D plays an important role in providing the consumers their daily dose of the vitamin. Vitamin D is necessary for metabolism of calcium, helps in absorption of calcium, maintains bone growth, and boosts immune system. Another prominent vitamin fortified in milk is vitamin A which is essential for vision, gene transcription, and assists in immune reactions. Vitamins play a vital role in human health hence its fortification in diet leads to certain health benefits (Pilz et al., 2016). Recently, the bioactive peptides derived from milk has reported to possess different functional properties such as stimulation of immune system, digestion, absorption of nutrients in body, prevention of obesity, and prevention of development of metabolic disorders (Li-Chan, 2015). Thus, the different bioactive components added to milk for the development of functional dairy beverages has appreciable effect on the well-being of the individual.

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3.6  Future Scope The world market has witnessed a huge demand for healthy beverages over the last decade. Market trends indicate that milk-based beverages are ideal vehicles for the bioactive food ingredients targeting lifestyle diseases. In the recent years the dairy products with “low” claim has increased tremendously. Different dairy beverage formulations customized to different consumers are now available in the market such as reduced sugar, reduced fat, mineral fortified beverages and probiotic milk, and whey beverages. Functional milk and dairy beverages have been considered as ideal vehicles for the delivery of potential bioactive components such as “probiotics” which are live microorganisms which help in maintaining good health through good intestine. The most common and preferred vehicle for delivery of probiotics is fermented milk beverages. Nowadays, research is also being carried out on the addition of the prebiotics to milk beverages which will help to feed the gut’s natural microflora and improve the digestive system and strengthen the immune system. Other trends occupying the present and future market of functional dairy beverages are the incorporation of omega-3 fatty acids, phytosterols, milk bioactive peptides, antioxidants, and dietary fiber in the milk. Although milk is considered as an excellent vehicle for the delivery of bioactive components however, a number of constraints are being faced by the manufacturers while incorporating the bioactive ingredients in dairy beverages. The scientific validation of the functional claims still remains the critical issue in this field. A few challenges being faced by the industry during the manufacture of functional dairy beverages include the selection of the species for the formulation of probiotic milk drink as it has to undergo heat treatment which could decrease its activity. Furthermore, the omega-3 fatty acids added to the milk are highly susceptible to heat and light and often develop undesirable flavor. In case of phytosterols, there occurs difficulty in the incorporation of it into the milk due to its insolubility. Moreover, the bioactive peptides from milk which are often fortified to milk for the development of functional dairy beverages are bitter in taste, have lower processing stability, poor emulsification properties, and flavor. Thus, precautions need to be followed during the addition and manufacturing of functional milk beverages. A proper sensory analysis of the functional dairy beverages needs to be carried out before launching them into the market. Furthermore, the food labeling laws governing the health benefits have become even stricter. The above issues can be dealt with more proficient research in the area, with scientific and clinical supporting evidences to support the health claims being made and thus acceptable functional dairy beverages can be manufactured for the consumers.

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References Anema, S.G., Lowe, E.K., Stockmann, R., 2005. Particle size changes and casein solubilisation in high-pressure-treated skim milk. Food Hydrocoll. 19, 257–267. Banon, S., Hardy, L., 1992. Colloidal approach of milk acidification by gluconodeltalactone. J. Dairy Sci. 75, 935–941. Barak, S., Mudgil, D., 2014. Locust bean gum: processing, properties and food ­applications—a review. Int. J. Biol. Macromol. 66, 74–80. Benkerroum, N., 2008. Antimicrobial activity of lysozyme with special relevance to milk. Afr. J. Biotechnol. 7, 4856–4867. Bhat, Z.F., Bhat, H., 2011. Milk and dairy products as functional foods: a review. Int. J. Dairy Sci. 6, 1–12. Brandelli, A., Daroit, D.J., Correa, A.P.F., 2015. Whey as a source of peptides with remarkable biological activities. Food Res. Int. 73, 149–161. Brody, E.P., 2000. Biological activities of bovine glycomacropeptide. Br. J. Nutr. 84, 39–46. Bruno-Barcena, J.M., Azcarate-Peril, M.A., 2015. Galacto-oligosaccharides and colorectal cancer: feeding our intestinal probiome. J. Funct. Foods 12, 92–108. Cashman, K.D., 2006. Milk minerals (including trace elements) and bone health. Int. Dairy J. 16, 1389–1398. Champagne, C.P., Mollgaard, H., 2008. Production of probiotic cultures and their addition in fermented foods. In: Farnworth, E.R.T. (Ed.), Handbook of Fermented Functional Foods. CRC Press, Boca Raton, pp. 513–532. Chen, Q., Liang, Y., Zhu, C., Yan, Y., Pang, G., 2013. Effects of casein glycomacropeptide on the early development of primary colorectal cancer in rats. Food Sci. Human Wellness 2, 113–118. Collomb, M., Schmid, A., Sieber, R., Wechsler, D., Ryhanen, E.L., 2006. Conjugated linoleic acid in milk fat: variation and physiological effects. Int. Dairy J. 16, 1347–1361. Conway, V., Gauthier, S.F., Pouliot, Y., 2014. Buttermilk: much more than a source of milk phospholipids. Anim. Front. 4, 44–51. Das, B., Roy, A.P., Bhattacharjee, S., Chakraborty, S., Bhattacharjee, C., 2015. Lactose hydrolysis by β-galactosidase enzyme: optimization using response surface methodology. Ecotoxicol. Environ. Saf. 121, 244–252. Datta, N., Deeth, H.C., 2001. Age gelation of UHT milk—a review. Food Bioprod. Process. 79, 197–210. Delavari, B., Saboury, A.A., Atri, M.S., Ghasemi, A., Bigdeli, B., Khammari, A., Maghami, P., Moosavi-Movahedi, A.A., Haertlé, T., Goliaei, B., 2015. Alpha-lactalbumin: a new carrier for vitamin D 3 food enrichment. Food Hydrocoll. 45, 124–131. Erzen, N., Kac, M., Pravst, I., 2014. Perceived healthfulness of dairy products and their imitations: nutrition experts’ perspective. Agro Food Ind. Hi Tech 25, 24–27. Fardet, A., 2015. Complex foods versus functional foods, nutraceuticals and dietary supplements. Agro Food Ind. Hi Tech 26, 20–24. Folkenberg, D.M., Martens, M., 2003. Sensory properties of low fat yoghurts. Part A: effect of fat content, fermentation culture and addition of non-fat dry milk on the sensory properties of plain yoghurts. Milchwissenschaft 58, 48–51. Galanakis, C.M., 2015. Separation of functional macromolecules and micromolecules: from ultrafiltration to the border of nanofiltration. Trends Food Sci. Technol. 42, 44–63. Gaucheron, F., 2005. The minerals of milk. Reprod. Nutr. Dev. 45, 473–483. German, J.B., Dillard, C.J., Ward, R.E., 2002. Bioactive components in milk. Curr. Opin. Clin. Nutr. Metab. Care 5, 653–658. Ghasempour, Z., Alizadeh, M., Bari, M.R., 2012. Optimisation of probiotic yoghurt production containing Zedo gum. Int. J. Dairy Technol. 65, 118–125. Gibson, G.R., Williams, C.M., 2000. Functional Foods: Concept to Product, first ed. Woodhead Publishing, Cambridge.

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Givens, D.I., Shingfield, K.J., 2006. Optimising dairy milk fatty acid composition. In: Williams, C., Buttriss, J. (Eds.), Improving the Fat Content of Foods. Woodhead Publishing Ltd, Cambridge, pp. 252–280. Holsinger, V.H., Posati, L.P., DeVilbiss, E.D., 1974. Whey beverages: a review. J. Dairy Sci. 57, 849–859. Horne, D.S., 1998. Casein interactions: casting light on the black boxes, the structure in dairy products. Int. Dairy J. 8, 171–177. Jelen, P., 1973. Whipping studies with partially delactosed cheese whey. J. Dairy Sci. 56, 1505–1511. Jiang, J., Xiong, Y.L., 2016. Natural antioxidants as food and feed additives to promote health benefits and quality of meat products: a review. Meat Sci. 120, 107–117. Kamau, S.M., Cheison, S.C., Chen, W., Liu, X.M., Lu, R.R., 2010. Alpha-lactalbumin: its production technologies and bioactive peptides. Compr. Rev. Food Sci. Food Saf. 9, 197–212. Kee, J., Ganesan, P., Kwak, H., 2010. Bioactive conjugated linoleic acid (CLA) in milk. Korean J. Food Sci. Anim. Resour. 30, 879–885. Kolanowski, W., Laufenberg, G., 2006. Enrichment of food products with polyunsaturated fatty acids by fish oil addition. Eur. Food Res. Technol. 222, 472–477. Korhonen, H., 2009. Milk-derived bioactive peptides: from science to applications. J. Funct. Foods 1, 177–187. Kroger, M., Meister, K., Kava, R., 2006. Low-calorie sweeteners and other sugar substitutes: a review of the safety issues. Compr. Rev. Food Sci. Food Saf. 5, 35–47. Kussendrager, K.D., van Hooijdonk, A.C.M., 2000. Lactoperoxidase: physico-chemical properties, occurrence, mechanism of action and applications. Br. J. Nutr. 84, 19–25. Levay, P.F., Viljoen, M., 1995. Lactoferrin: a general review. Haematologica 80, 252–267. Li-Chan, E.C., 2015. Bioactive peptides and protein hydrolysates: research trends and challenges for application as nutraceuticals and functional food ingredients. Curr. Opin. Food Sci. 1, 28–37. Lichtenstein, A.H., Appel, L.J., Brands, M., Carnethon, M., Daniels, S., Franch, H.A., Franklin, B., Kris-Etherton, P., Harris, W.S., Howard, B., Karanja, N., 2006. Diet and lifestyle recommendations revision 2006. Circulation 114, 82–96. Mahmoud, M.I., Malone, W.T., Cordle, C.T., 1992. Enzymatic hydrolysis of casein: effect of degree of hydrolysis on antigenicity and physical properties. J. Food Sci. 57, 1223–1229. Mahoney, R.R., 1998. Galactosyl-oligosaccharide formation during lactose hydrolysis: a review. Food Chem. 63, 147–154. Makinen, O.E., Wanhalinna, V., Zannini, E., Arendt, E.K., 2016. Foods for special dietary needs: non-dairy plant-based milk substitutes and fermented dairy-type products. Crit. Rev. Food Sci. Nutr. 56, 339–349. Markus, C.R., Jonkman, L.M., Lammers, J.H., Deutz, N.E., Messer, M.H., Rigtering, N., 2005. Evening intake of alpha-lactalbumin increases plasma tryptophan availability and improves morning alertness and brain measures of attention. Am. J. Clin. Nutr. 81, 1026–1033. McCrae, C.H., 1994. Homogenization of milk emulsions: use of microfluidizer. Int. J. Dairy Technol. 47, 28–31. McGregor, R.A., Poppitt, S.D., 2013. Milk protein for improved metabolic health: a review of the evidence. Nutr. Metab. 10, 46–58. Mudgil, D., 2017. Introduction to functional foods. In: Mudgil, D., Barak, S. (Eds.), Functional Foods: Sources and Health Benefits. Scientific Publishers, Jodhpur, pp. 1–16. Mudgil, D., Barak, S., 2013. Composition, properties and health benefits of indigestible carbohydrate polymers as dietary fiber: a review. Int. J. Biol. Macromol. 61, 1–6. Mudgil, D., Barak, S., 2016. Development of functional buttermilk by soluble fibre fortification. Agro Food Ind. Hi Tech 27, 44–47.

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Mudgil, D., Barak, S., Khatkar, B.S., 2011. Effect of hydrocolloids on the quality characteristics of tomato ketchup. Carpath. J. Food Sci. Technol. 3, 39–43. Mudgil, D., Barak, S., Khatkar, B.S., 2012. Process optimization of partially hydrolyzed guar gum using response surface methodology. Agro Food Ind. Hi Tech 23, 13–15. Mudgil, D., Barak, S., Khatkar, B.S., 2014. Guar gum: processing, properties and food applications—a review. J. Food Sci. Technol. 51, 409–418. Mudgil, D., Barak, S., Darji, P., 2016. Development and characterization of functional cultured buttermilk utilizing Aloe vera juice. Food Biosci. 15, 105–109. Mulder, A.M., Connellan, P.A., Oliver, C.J., Morris, C.A., Stevenson, L.M., 2008. Bovine lactoferrin supplementation supports immune and antioxidant status in healthy human males. Nutr. Res. 28, 583–589. Ostlund Jr, R.E., 2004. Phytosterols and cholesterol metabolism. Curr. Opin. Lipidol. 15, 37–41. Ozer, B.H., Kirmaci, H.A., 2010. Functional milks and dairy beverages. Int. J. Dairy Technol. 63, 1–15. Paquin, P., 2009. Functional and Speciality Beverage Technology, first ed. Woodhead Publishing, Cambridge. Pilz, S., Verheyen, N., Grübler, M.R., Tomaschitz, A., März, W., 2016. Vitamin D and cardiovascular disease prevention. Nat. Rev. Cardiol. 13, 404–417. Playne, M.J., Bennett, L.E., Smithers, G.W., 2003. Functional dairy foods and ingredients. Aust. J. Dairy Technol. 58, 242–264. Prazeres, A.R., Carvalho, F., Rivas, J., 2012. Cheese whey management: a review. J. Environ. Manag. 110, 48–68. Rittling, S.R., Singh, R., 2015. Osteopontin in immune-mediated diseases. J. Dent. Res. 94, 1638–1645. Rojas, E., Torres, G., 2013. Isolation and recovery of glycomacropeptide from milk whey by means of thermal treatment. Food Sci. Technol. (Campinas) 33, 14–20. Roy, B.D., 2008. Milk: the new sports drink? A review. J. Int. Soc. Sports Nutr. 5, 15–21. Sabokbar, N., Khodaiyan, F., 2015. Characterization of pomegranate juice and whey based novel beverage fermented by kefir grains. J. Food Sci. Technol. 52, 3711–3718. Seifu, E., Buys, E.M., Donkin, E.F., 2005. Significance of the lactoperoxidase system in the dairy industry and its potential applications: a review. Trends Food Sci. Technol. 16, 137–154. Shree, K.D., Deshpande, H.W., Bhate, M.A., 2017. Studies on exploration of psyllium husk as prebiotic for the preparation of traditional fermented food “buttermilk”. Int. J. Curr. Microbiol. App. Sci. 6, 3850–3863. Silva, R.R., Rodrigues, L.B.O., Lisboa, M.M., Pereira, M.M.S., de Souza, S.O., 2014. Conjugated linoleic acid (CLA): a review. Int. J. Appl. Sci. Technol. 4, 154–170. Sinha, R., Radha, C., Prakash, J., Kaul, P., 2007. Whey protein hydrolysate: functional properties, nutritional quality and utilization in beverage formulation. Food Chem. 101, 1484–1491. Smithers, G.W., 2015. Whey-ing up the options—yesterday, today and tomorrow. Int. Dairy J. 48, 2–14. Villegas, B., Tárrega, A., Carbonell, I., Costell, E., 2010. Optimising acceptability of new prebiotic low-fat milk beverages. Food Qual. Prefer. 21, 234–242. Walker, G.P., Dunshea, F.R., Doyle, P.T., 2004. Effects of nutrition and management on the production and composition of milk fat and protein: a review. Aust. J. Agric. Res. 55, 1009–1028. Ward, O.P., Singh, A., 2005. Omega-3/6 fatty acids: alternative sources of production. Process Biochem. 40, 3627–3652. Zou, X., Guo, Z., Jin, Q., Huang, J., Cheong, L., Xu, X., Wang, X., 2015. Composition and microstructure of colostrum and mature bovine milk fat globule membrane. Food Chem. 185, 362–370.

NEW TRENDS AND PERSPECTIVES IN FUNCTIONAL DAIRY-BASED BEVERAGES

4

Celia Rodríguez-Pérez⁎, Sandra Pimentel-Moral†,‡, Javier Ochando-Pulido§ *

UCD School of Agriculture and Food Science, Institute of Food and Health, University College Dublin (UCD), Dublin 4, Ireland †Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain ‡ Research and Development Functional Food Centre (CIDAF), Health Science Technological Park, Granada, Spain §Department of Chemical Engineering, University of Granada, Granada, Spain

4.1 Introduction The scientific and cultural development of our society has caused notable changes in dietary habits. In this regard, consumers are aware of the diet-health relationship which is reflected in the higher demand of products capable of preventing or alleviating different diseases further than satisfy hunger and to provide necessary nutrients for humans. In this context emerged the term of functional foods which were first called Food for Specified Health Use (FOSHU) and their labeling regulation was established by the Japanese Minister of Health and Welfare in the 1980s. Much has changed since then, and currently several definitions of today known as functional foods are used, mainly depending on the country (Siro et al., 2008). However, all definitions agree in the fact that functional foods are a food with proven to affect beneficially one or more target functions in the body beyond adequate nutritional effects, thus, improving the consumer health and wellbeing and/or reducing the risk of disease (Howlett, 2008). Briefly, in general terms, functional foods can be divided into natural or processed, which include: (a) food to which component has been added; (b) foods from which one or more components have been removed; (c) foods where the nature of one or more components has been modified; (d) foods in which the bioavailability of one or more components has been modified; or (e) any combination of the aforementioned possibilities (Roberfroid, 2002). In this context, Milk-based Beverages. https://doi.org/10.1016/B978-0-12-815504-2.00004-9 © 2019 Elsevier Inc. All rights reserved.

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the development of functional foods has emerged as a promising tool for preventing nutrition-related diseases and improves physical and mental well-being of consumers. The market of functional foods is one of the fastest growing food sectors a growth rate of 6.9% from 2011 to 2012 with sales of US$43.9 billion (Khan et al., 2013). It is expected to reach an annual growth rate of 8.7 globally by 2020 (Bagchi and Nair, 2016). Focus on dairy products, total milk production was estimated at 818 million tons in 2015 leaded by the European Union and Asia and its average consumption was estimated as near 115 kg/capita/year (International Dairy Federation, 2016). Total dairy sector accounted for 13.6% of the total turnover of the food and drink industry in 2012 (EU report). According to the latest reports from the United States Department of Agriculture (USDA), while the sales of whole milk decreased from US$22 to US$20 million during the last 10 years, the intake of low-fat milk increased from US$8.5 to US$9.6 million (USDA, 2017). In 2015, the milk production increased in the EU. The whole milk was mainly used for cheese, butter, and ice production but 11% was used for drinking milk, 4% for acidified milk, and 3% was employed for the production of other products such as milk-based beverages (EUROSTAT, 2017). According to Özer et al., dairy-based functional foods account near 43% of the market which is led by fermented dairy products (Özer and Kirmaci, 2010). It is no wonder due to most dietary guidelines worldwide recommend the intake of dairy products for being a good source of calcium and high-quality proteins. Besides, according to the Food and Drug Administration (FAO), this group of foods is considered one of the major sources of energy and nutrient (mainly Vitamin D and calcium) in many countries (FAO, 2013). At global level, milk contributes on average 134 kcal of energy/ capita per day and it supposes is the fifth largest provider of energy and the third large provider of protein and fat for human being (FAO, 2016). Moreover, an inverse association between total dairy intake and risk of type 2 diabetes has been reported in a recent meta-analysis on dairy intake and diabetes incidence included 22 cohort studies with a total of 579,832 subjects (Gijsbers et al., 2016). Furthermore, some studies have demonstrated that children included in dairy intake group were 38% less likely to be overweight or obese compared with those in the lowest dairy intake group (Lu et al., 2016). However, the intake of dairy-based beverages and especially milk has decreased significantly in the last decades among children and adolescents (Miller, 2017) with the nutritional consequences that it could lead to. It has been reported that beverages play a major role in the diets of children and adolescents (FDA, 2015) but the latest reports show that these group of population do not reach the recommendations for dairy product intake, that is, three servings (approximately 500 mL) per day for children under the age of 9 years and three–five servings (600 mL) per day for adolescents (Dror and Allen, 2014). Thus, the formulation

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of functional dairy-based beverages emerges as an important strategy to prevent or supply the deficit not only in the abovementioned groups of population but also in general population. Due to its high production and the suitability of dairy as vehicle of bioactive food ingredients, market trends highlight dairy-based beverages as a growing segment of the functional food sector. Within dairy beverages, fresh and fermented milk and yogurt drinks are the most common products. Functional dairy-based beverages can be divided into two main groups: • Added-value dairy beverages: this category includes those beverages in which one or more components have been removed, for example, lactose-free milks, low-fat milk, or low-fat drinkable yogurt. These kinds of products are commonly directed to specific groups of population. • Fortified dairy beverages: fortification increases the amount of nutrients, commonly present before processing, in a food product. This is the case of calcium, magnesium, conjugated linoleic acid (CLA), whey proteins (WPs), or fat-soluble vitamins such as A or D. • Enriched dairy beverages: this category encompasses dairy beverages to which bioactive component has been added to promote health benefits beyond their basic nutritional value, for example, probiotics, prebiotics, phytochemicals, fiber, sterols, or ­omega-3-enriched dairy beverages, among others. A number of review articles have focused on describing one aspect of functional dairy-based beverages. However, none of them have addressed a comprehensive overview of the state of the art including scientific and technological processes which will be discussed along this chapter.

4.2  Bioactive Compounds in Milk-Based Beverages Bioactive compounds have been defined as food components with health benefits which typically occur in small quantities in certain foods (Singh, 2016). In the matter of milk-based beverages, several bioactive compounds have been described, that is, vitamins, minerals, lipids, carbohydrates, enzymes, casein, and WPs and derive peptides and oligosaccharides (Fig. 4.1) (Park and Nam, 2015). In this regards, common milk is often considered as a natural functional food since it contains multiple of different bioactive components. Vitamins and minerals are considered as essential due to they are involved in several reactions in the body including metabolism cofactors, oxygen transport and antioxidants and enzyme functions, bone formation, water balance maintenance, and oxygen transport, respectively (Fortmann et al., 2013). Among water soluble vitamins, milk is

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Lactose

Carbohydrates

Oligosaccharides

Ca Mg Conjugated linoleic acid (CLA)

Lipids

Minerals

P K Na

Zn

Fat-soluble A, D, E, K

Vitamins

Caseins Proteins

κ-Casein β-Casein α-Caseins

Lactoferrin

Water-soluble B2, B9, B12, C

β-Lactoglobulin Whey proteins

α-Lactoalbumin Glycomacropeptide

Fig. 4.1  Main bioactive compounds in milk-based beverages.

rich in folate (vitamin B9), riboflavin (vitamin B2), cobalamin (vitamin B12), and vitamin C which are directly implicated in the reactions of intermediary metabolism related to energy production and redox status (Heer et al., 2015). Their concentrations in milk have been estimated as 50 μg/L, 1.8 mg/L, 4.4 μg/L, and 15 mg/L, respectively, according to the USDA Food Composition Databases. As they are eliminated in urine, they have to be daily incorporated through diet. On the other hand, vitamins A, D, E, and K are the majority fat soluble vitamins in milk and their content will depend on the fat composition. The activity of vitamin A is related to vision maintenance, body growth, and immune function (de Azevedo Paiva et al., 2010; Prietl et al., 2013). Vitamin D regulates the circulating levels of calcium and phosphorus, thus, is implicated in bone maintenance (Reid et al., 2014). Vitamin E is a potent antioxidant which commonly protects fatty acids in cell membranes from free radicals (Jiang, 2014) while vitamin K is also implicated in bone health and blood coagulation process (Vermeer, 2012). However, despite their representative presence in milk, some of these vitamins are not always present in natural dairy-based beverages due to the processing as will be discussed later. Among minerals, calcium has been probably the most studied bioactive compound. Dairy foods and specifically milk are the major source of calcium worldwide. A large body of scientific evidence

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supports the direct relationship between the intakes of calcium from dairy foods and the reduction of the risk of osteoporosis (Huth et al., 2006). Furthermore, latest research evidenced the effect of dairy calcium from milk- and cheese-based diets including 1700 mg calcium per day on fecal fat excretion (Soerensen et al., 2014). But milk and then milk-based beverages are good sources of calcium, magnesium, phosphorus, potassium, sodium, and zinc. Their contents are estimated 1100, 130, 930, 1510, 490, and 3.8 mg/L of milk, respectively (USDA) and their biological activities have been reviewed elsewhere (Haug et al., 2007). Milk fat is the richest dietary natural source of CLA with an average 4.5 mg CLA/g of fat (Chinnadurai and Tyagi, 2011). CLA is an 18‑carbon polyunsaturated bioactive fatty acid with two conjugated double bonds. Since the study of its anticancer properties in 1979 (Pariza et al., 1979), the number of research focused on the effects of CLA on human health has been increased. Currently, it is believed that its major physiological role is related to metabolic changes that promote the reduction of the lipogenesis and the potentiation of lipolysis (Lehnen et al., 2015). Despite its healthy effect have been extensively reviewed (Lehnen et al., 2015; Biglu et al., 2017; Rahbar et al., 2017; Shokryazdan et  al., 2017; Kim et  al., 2016), some discrepancies exist regarding its lipid profile enhancement. Jenkins et al. showed significant lower triacylglycerol (TG) serum concentration in 34 untrained to moderately trained men after the intake of 5.63 g of total CLA isomers compared with placebo group (Jenkins et  al., 2014). However, in a 401 volunteers who received 2.5 g 9-cis, 11-trans CLA/d and 0.6 g 10-trans, 12cis CLA/d in lipid concentrations (Sluijs et al., 2010) compared with control group. In a recent systematic review and meta-analysis which included 1111 significant articles concluded that CLA consumption improves weight and body mass index (BMI) with no changes in TG in patients with metabolic syndrome (Kim et al., 2016). Apart from lipids, vitamins, and minerals, milk is made up between 30% and 35% of proteins. The major milk proteins include WPs, caseins, and milk fat globule membrane (MFGM) proteins which are natural vehicles that deliver essential micronutrients (e.g., calcium or amino acids) and immune system components (e.g., lactoferrin and immunoglobulins) from mother to the newborn (Livney, 2010). Milk proteins consist on near 20% of WP which is considered as a rapidly digested and absorbed protein which includes β-lactoglobulin (35%– 65%), α-lactalbumin (12%–25%), and glycomacropeptide (20%–25%) (Veldhorst et  al., 2009). WP contains bioactive peptides which are inactive while encrypted in the sequence of original protein but can be released by hydrolysis by digestive enzymes, proteolytic microorganisms, and/or the action of plant or microbial proteases (Brandelli et al., 2015). Thus, WP hydrolysates are rich in essential amino acids

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and peptides which have proven to have hypotensive, anticancer, antioxidative, antimicrobial, or immunomodulatory effects (Sultan et al., 2017; Sah et al., 2015; Duarte et al., 2011; Min et al., 2005; Morris and FitzGerald, 2008). Due to their nutritional and physiological properties, WPs are often the preferred source for ready-to-drink (RTD) protein beverages (Rittmanic, 2006) mainly by sportsmen to strengthen the muscle anabolism and promoting muscle biosynthesis (Deutz et al., 2014; Patel, 2015). Moreover, WPs have shown to reduce energy intake and affect satiety. In fact a recent double-blind, randomized clinical trial aimed to determine the effects of added supplemental protein to the habitual diet of free-living overweight and obese adults the body weight, fat mass, and waist circumference of the group consuming the WP were lower than the group consuming carbohydrates (Baer et al., 2011). On its behalf, caseins (κ-casein, β-casein, and the α-caseins) represent among 24–28 g/L of milks (Livney, 2010) and it represents 80% of the total protein (Silva and Malcata, 2005). Caseins from dairy products have demonstrated to exhibit high antioxidant activity through different mechanisms as recently reviewed by Fardet and Rock (2017). Caseins from milk or other dairy products are also important sources of bioactive peptides which, as occurred from bioactive peptides from WP, have proven to provide hypotensive, immunomodulatory, opioid agonist, opioid antagonist, antithrombotic, mineral binding, hypocholesterolemic, or antioxidant effects (Hartmann and Meisel, 2007). Regarding bioactive enzymes from milk, lactoferrin is an iron-­ binding glycoprotein which key role in the defense mechanisms of the mammary gland of lactating animals (Cheng et  al., 2008). Early studies reviewed the antibacterial effect of lactoferrin and derivatives against pathogens such as Candida albicans, Clostridium perfringens, Helicobacter pylori, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella enteritidis, or Vibrio cholera and some virus, for example, hepatitis C, G and B virus HIV-1 or herpes simplex virus (Farnaud and Evans, 2003; Pan et al., 2007). However, a recent research has also demonstrated the in vitro antitumor activity on colon cancer cells (Jiang and Lönnerdal, 2016). The same anticancer activity was reported by Sugihara et al. in vivo (Sugihara et al., 2017). Among carbohydrates from milk, lactose is the most representative. Its concentration in milk is 53 g/L (USDA) and it has been directly related to intestinal calcium absorption mainly when calcium solubility or active vitamin D-dependent calcium absorption is limited (Areco et al., 2015). On their behalf, oligosaccharides are considered as minor bioactive components from milk and derivatives. More than 30 oligosaccharides have been identified in bovine and caprine milk (Martinez-Ferez et al., 2006). In human milk, oligosaccharides represent between 5 and 10 g/L (Korhonen, 2009) and their main function

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has been reported to confer protection to infants through the synergy of multiple compounds related to structural and functional diversity (Zivkovic and Barile, 2011). Several studies have demonstrated that bovine milk contains oligosaccharides that are analogous to those from human milk, thus, providing similar protection (Gopal and Gill, 2000; Bode, 2006). In fact, in a clinical study carried out in 15 infants feed with a bovine milk formula supplemented with a mixture of fructo and galato-oligosaccharides, stimulated the growth of bifidobacteria in the intestine in a similar way that the human milk did (Boehm et al., 2002). Apart from conferring prebiotic effect, some of the activities related to milk oligosaccharides are antiadhesion effects, antiinflammatory properties, and growth-related characteristics of intestinal cells (Albrecht et al., 2014).

4.3  New Trends in Functional Dairy Beverages Development As abovementioned, milk-based beverages have proven to be natural, multi-component, and nutrient-rich beverages. In this sense and due to the consumer dietary awareness, focused on health promotion, the development of functional dairy beverages appears as a valuable tool for reach the goals of consumers.

4.3.1 Omega-3 Fatty Acids The quality of dietary fats plays a significant role in the development and progression of chronic diseases such as cardiovascular disease (CVD) and related pathologies. In this regard, the replacement of saturated fatty acids by oleic acid or omega-3 fatty acids, for example, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have demonstrated favorable outcomes in blood lipids, mainly by decreasing low-density lipoprotein (LDL) cholesterol, triglycerides, and total cholesterol (Allman-Farinelli et  al., 2005). Omega-3-enriched milks were introduced in the market in 1995 and since then, several omega-3-enriched milks employing either liquid or microencap­ sulated fish or linseed oils (Kolanowski and Laufenberg, 2006) are available in the market (see Table 4.2). However, milks enriched in unsaturated fatty acids are more susceptible to lipid oxidation. In this regard, many attempts to prevent oxidation have been proposed mainly by employing plant extracts such as oregano such as oregano, green tea or linseed oil, among others (Boroski et  al., 2012; Giroux et  al., 2010; Song et al., 2015). The use of oregano extract (OE) and oregano essential oil (OEO) as antioxidants (0.001–0.1 g/100 g) in dairy beverages (low-heat skim

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milk) enriched with linseed oil (2 g/100 g) was studied by Boroski et al. (2012). OE was added, and each mixture was stirred for 15 min, with pH adjustment (6.7), and thereafter preemulsified (40°C) for 3 min at 8000 rpm using an Ultra-Turrax T25 and homogenized with a ­single-stage Emulsiflex-C5 homogenizer (20 MPa homogenization pressure for the first two passes and 3.5 MPa for the third one). Samples were batch pasteurized at 63.5°C for 30 min in stainless steel cups. In case of dairy beverages enriched with OEO, the oil was directly mixed with the linseed oil before homogenization. Both OE, containing 269 mg gallic acid equivalents per gram, and OEO reduced light- and heat-induced oxidation of omega-3 fatty acids and change in color during 10-day storage without affecting dairy beverage physical stability. OE showed better antioxidant properties than OEO [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay], yielding higher efficiency in preventing the formation of conjugated dienes, hexanal, and propanal, as well as the depletion of oxygen induced by heat or light oxidation. Song et al. (2015) suggested that protein interactions may be useful in stabilizing flavan-3-ols through thermal processing in dairy beverages. They examined the potential of protein affinity to stabilize flavan-3-ols in thermal treatment in single strength (36.2 protein/L) and quarter strength (9.0 g protein/L) milk, incubated with epigallocatechin gallate and green tea extract (62°C or 37°C for 180 min). Major polyphenol to protein ratios were found to increase first-order degradation rates, thus reducing formation of oxidation products. Liquid chromatography-mass spectrometry (LC-MS) quantification of intact flavan-3-ols and select autooxidation products [theasinesins (THSNs) and P-2 dimers] revealed the presence of galloyl and hydroxy moieties was associated with higher stability of monomeric flavan-3-ols with increasing protein concentrations, whereas the absence of these moieties led to no observable improvements in stability, pointing for the potential for protein affinity to stabilize flavan-3-ols in thermal treatment. The authors indicated noncovalent interactions between flavan-3-ols, autooxidation dimers to proteins and covalent bonding of quinones to proteins as potential mechanisms. Adding a small fraction of milk protein as preheated protein sugar blend in functional dairy beverage formulations is a promising approach to prevent the oxidation of n-3 polyunsaturated fatty acids during sterilization treatment, as reported by Giroux et  al. (2010). They examined the use of heated native milk protein-sugar blends as antioxidant in dairy beverages enriched with linseed oil. Antioxidant preparations (5 mL/100 mL) were obtained by heating aqueous dispersions of milk protein (3.5 g/100 g) and sugars (10 g/100 mL, with various proportions of lactose, sucrose, and their monosaccharide mixtures glucose/galactose and glucose/fructose) at 110°C for 10 min. The use of monosaccharide [glucose-fructose equimolar mixture (GF)

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and ­glucose-galactose equimolar mixture (GG)] in the formulation improved sensibly their antioxidant properties. Nonheated blends did not reduce lipid oxidation during sterilization, whereas preheated milk protein sugar blends provide Maillard reaction products in the early stage of sterilization, which efficiently prevent lipid oxidation of dairy beverages. Hexanal and propanal concentrations after sterilization were respectively reduced by 100% and 78% when the final concentration of monosaccharides in dairy beverages reached 0.4 g/100 mL. On the other hand, Arancibia et al. (2011) examined the effectiveness of λ-carrageenan and a blend (50:50) of short- and long-chain inulin as fat replacers in dairy beverages prepared with carboxymethyl cellulose (CMC). Results showed that both λ-carrageenan and the inulin blend could be used as fat replacers in CMC-based dairy beverages and consumers could distinguish among samples that differed in color and rheological behavior.

4.3.2  Probiotics and Prebiotics Together with omega-3 fatty acids, probiotics and prebiotics are probably the most employed bioactives to formulate functional dairybased beverages. An extended use of probiotic bacteria in dairy products is being recently experienced and research on the development of new functional food products based on milk is promising, given that they are an excellent medium for live and active cultures (Kandylis et al., 2016), as milk is rich in Omega-3, phytosterols, isoflavons, CLA, minerals, and vitamins (Homayouni et al., 2008, 2012). The intake of functional dairy-based beverages enriched in probiotics is an optimum way to reestablish the intestinal microfloral balance. However, the culture must be native of the human gastrointestinal tract, be able to ferment prebiotics and to adequately survive the passage through the stomach and small bowel in adequate numbers, and colonize in the site of action (Kandylis et  al., 2016). For the dairy product to be considered a valuable alternative to deliver probiotics, it must comply with neutral pH, high enough total solids level, absence of oxygen, and near to ambient temperatures (Homayouni et al., 2012; Kandylis et al., 2016). In this regard, Lactobacillus acidophilus (L. acidophilus) and Bifidobacterium animalis subsp. lactis are the most commonly used lactic acid bacteria (LAB) as probiotics, usually combined with Streptococcus thermophilus (S. thermophilus) because they lack essential proteolytic activity (Casarotti et al., 2014; Fijan, 2014; Kandylis et al., 2016). LAB have been proven to carry different nutritional and therapeutic properties to fermented milk products (Shiby and Mishra, 2013), together with the suppression of the growth of pathogens directly or through the production of antibacterial substances, such as

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­ acteriocins, as a result of to the quick and abundant utilization of carb bohydrates present in food matrices, with simultaneous accumulation of lactic and acetic acids (Kandylis et al., 2016; Ganzle, 2015; O’Connor et al., 2015). In traditional acidophilus milk production, milk is heated at 95°C for 1 h or at 125°C for 15 min, stimulating the growth of L. acidophilus by providing denatured proteins and released peptides (Vedamuthu, 2006). Thereafter, cooling down to 37°C is performed and maintained at these conditions for 3–4 h in order to allow germination of spores. Then, milk is re-sterilized to destroy almost all vegetative cells. Unless skim milk is used, the heat-treated milk is homogenized and cooled down to inoculation temperature (37°C). Furthermore, L. acidophilus is added as active bulk culture, commonly at 2%–5%, and the inoculated milk is left to ferment until pH 5.5–6.0 or ~1.0% lactic acid is attained, with no alcohol (Surono and Hosono, 2002). Fermentation lasts 18–24 h under inactive conditions. Thereafter, the number of viable L. acidophilus colonies is about 2–3 × 109 cfu/ mL, decreasing until consumption time (Vedamuthu, 2006). To solve this, 25% L. acidophilus culture is replaced by a mixture of S. thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus out. The warm product is then rapidly cooled to Tc

CLA-loaded liposome suspension

Size

EPR

Fig. 6.1  Conjugated linoleic acid (CLA) loaded liposome preparation scheme using ethanol injection method. GC, gas chromatography; TEM, transmission electron microscopy; EPR, electronic paramagnetic resonance.

trans-C18:1 (1.6 times) and PUFA including CLA (1.4 times) and α-linolenic acid (ALA) (1.6 times), as compared with conventional fermented milks. These higher levels were the result of both initial percentage in the milk and increase during fermentation, with no further modification during storage. Finally, use of bifidobacteria (B. animalis subsp. lactis HN019) slightly increased CLA relative content in the conventional fermented milks, whereas no difference was seen in organic fermented milks. Particularly, the increasing of CLA during fermentation was explained by Ekinci et al. (2008), indicating that enzymatic reactions occurred in the biohydrogenation pathway, thus increasing CLA level during the production of fermented products. Similar results were reported by Oliveira et al. (2009). The presence of CLA-producing LAB strains in milk-fermented beverages

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has a t­ remendous potential to increase the CLA content. Dahiya and Puniya (2017) isolated and characterized CLA-producing lactobacilli from different dairy products (breast milk, fermented milk) and human feces of Indian origin. Overall, they found that L. plantarum isolated from human infant feces (HIF15) was found as the most efficient CLA producer.

6.4.4 Vitamins and Minerals Compared with milk, yogurt is more nutritious and is an excellent source of protein, calcium, phosphorus, magnesium, zinc, and some vitamins of complex-B such as riboflavin, thiamin, cobalamin, folate, and niacin. The healthy image associate with yogurt has led to increase in its consumption and thus, it is considered as ideal vehicle for delivery of additional vitamins and minerals (Kaushik and Arora, 2017; Williams et  al., 2005). In this context, fortified dairy products constitute a safe, sustainable, and cost-effective approach to enhance nutritional status of the people (Herrero et al., 2002). The content of vitamins in yogurts is influenced by several f­ actors including the vitamin content of base milk, the heat treatment, production and utilization by starter bacteria, and the storage conditions (Deeth and Tamime, 1981). The fortification of fermented products with different vitamins is a common practice in dairy industries. The assessment of the appropriate dose of vitamins as well as their stability during storage and the effect of fortification on yogurt composition and quality have been widely investigated (Ilic and Ashoor, 1988; Kazmi et  al., 2007; Boeneke and Aryana, 2007, 2008; Hanson and Metzger, 2010; Jafari et al., 2016). Recently, fortification of yogurts with vitamins A and D and folic acid has attracted scientific and public health interest. Vitamin A is an essential nutrient required in small amounts by humans for the normal functioning of the visual system, growth and development, maintenance of epithelial cellular integrity, immune function, and reproduction. Milk and dairy products with increased levels of vitamin A are selling worldwide. They provide a significant quantity of vitamin A, especially to infants and children (HerreroBarbudo et  al., 2005). However, variations in the concentration of added vitamins, as well as dairy products that do not meet the required levels of vitamins expressed in the label claims, have been reported (Herrero et al., 2002). Among the reasons of this finding can be mentioned: the conditions under which vitamin ingredients are stored, the methodology used to add them, the point during processing at which they are added, etc. (Hicks et al., 1996; Herrero-Barbudo et al., 2005). Vitamin D is necessary for skeletal development and plays a key role in the regulation of the level of calcium and phosphorus in s­ erum.

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Deficiency contributes to diseases such as childhood rickerts, osteoporosis, and osteomalacia. Besides, low serum concentrations of vitamin D have been associated with impaired glucose tolerance and diabetes, and an increase in the risk of cancer, obesity, cardiovascular disease, and autoimmune disorders (Hanson and Metzger, 2010; Nikooyeh et al., 2011). Due to foods naturally rich in vitamin D are limited, fluid milk is one of the world´s predominant vehicles to deliver this nutrient. The fortification of yogurts has also been proven successful (Kaushik and Arora, 2017). Overall, vitamin D was stable over the process and the shelf life of fermented products (Kazmi et al., 2007; Hanson and Metzger, 2010; Jafari et  al., 2016), and also their intake enhanced of the vitamin D status of the general population. Vitamin D-fortified yogurts consumed by healthy menopausal women produced an increase in the serum levels of the main metabolite of vitamin D (Bonjour et al., 2017). Daily intake of vitamin D-fortified yogurt with or without added calcium improved glycemic status and selected bone and endothelial biomarkers in subjects with type 2 diabetes (Nikooyeh et al., 2011; Shab-Bidar et al., 2011; Neyestani et al., 2015). Milk and fermented products are not good natural sources of folic acid (Forssén et al., 2000); however, the bioavailability and stability of folates is much better in dairy products than in other foods (McNulty and Pentieva, 2004). Studies have shown that supplementation of folic acid during initial stages of pregnancy can prevent neural tube defects. In addition, an adequate intake has also been shown to reduce the risk of colorectal and breast cancer and have a protective role against coronary heart disease. Due to the public health relevance, the fortification of dairy products with folates has been implemented worldwide (Holasová et al., 2005; Boeneke and Aryana, 2007, 2008). Minerals ions are nutrients required by organisms to perform functions essential for life such as: the regulation of enzyme activities, the maintenance of acid-base balance and osmotic pressure, the facilitation of the transfer through the membrane of essential nutrients, and the maintenance of nerve and muscular irritability (Achanta et  al., 2007). Low intake or absorption of minerals generates deficiencies related to many human health problems such as stunted growth in children, weak bones, and deteriorated immune responses (SantillánUrquiza et al., 2017). Among minerals, calcium occupies a central place in bone metabolism. Sound scientific evidence establishes that high calcium (Ca) consumption promotes bone health (Heaney, 2000; Rizzoli, 2014; Burckhardt, 2015). Besides, an adequate Ca intake has been related with reduced risk of osteoporosis, hypertension, colon cancer, kidney stones and obesity, among other pathologies (Williams et  al., 2005; Singh and Muthukumarappan, 2008). Deficiency of Ca in the diet is a common problem. It is generally accepted that milk products make

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an essential contribution to human requirements. Dairy products usually contain substantial amount of highly bioavailable Ca (Singh and Muthukumarappan, 2008). In particular, bioavailability from yogurt is even higher than that from milk and other dairy products due to the higher acidity of yogurt, which facilitates intestinal Ca absorption (Ünal et al., 2005). However, the intake of a single portion of milk or yogurt is far from meeting daily Ca requirements, and consequently, Ca-enriched dairy products have been developed. The strategies of Ca fortification include the use of soluble or insoluble salts. Among the most tested chemical forms can be mentioned: calcium lactate, calcium gluconate, calcium chloride, calcium citrate, calcium carbonate, calcium phosphate, tricalcium phosphate, and tricalcium citrate, which can be added alone or in different combinations. More recently, the use of egg-shell powder and natural milk calcium as source of Ca has been also reported (Salman et al., 2012; Al Mijan et al., 2014). The selection of the appropriate source for a specific use takes into account properties of the salt such as: solubility, calcium content, taste, bioavailability, and costs (Münchbach and Gerstner, 2010). The effect of added Ca salts on the physicochemical, microbiological, and rheological properties of a wide range of products, including yogurts and other fermented milks obtained from milk from different species (cow, sheep, buffalo, etc.) and with different characteristics (stirred, probiotics, with fruits, etc.), has been widely investigated, and the obtained results were contradictory (Pirkul et al., 1997; Ramasubramanian et al., 2008; Singh and Muthukumarappan, 2008; Shamsia, 2010; Yonis et  al., 2013; Kaushik and Arora, 2017; Santillán-Urquiza et al., 2017; Szajnar et al., 2017). In this sense, the level and the type of added salt are crucial. Besides, it is well known that some salts have effects more adverse than others. Pirkul et al. (1997) reported that fortified yogurts with calcium lactate and calcium glutamate at the levels tested were significantly different from controls for titratable acidity and pH. Szajnar et al. (2017) studied different calcium compounds as fortifiers and found that the effect on total acidity and pH was dependent on the type of salt and changed during incubation and storage. Kaushik and Arora (2017) reported that acidity, pH, and syneresis of yogurt fortified with calcium phosphate or calcium citrate did not differ from the values obtained in control yogurts. The study of the impact of fortification on rheology and textural properties of fermented products has also revealed contradictory results. Calcium carbonate and tricalcium phosphate have limited solubility and often contributes to “gritty” texture. The fortification with calcium chloride and calcium bisglycinate produced a darkening of yogurts (Szajnar et  al., 2017), and certain properties such as firmness and viscosity decreased in calcium phosphate fortified yogurt

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(Kaushik and Arora, 2017). By contrast, some authors observed that the added Ca salts did not affect the rheological properties (firmness, viscosity, smoothness, hardness, adhesiveness, chewiness, and cohesiveness) or they even improve them (Ramasubramanian et al., 2008; Yonis et al., 2013; Al Mijan et al., 2014; Kaushik and Arora, 2017). Overall, the firmer structure of fortified yogurt is attributed to the higher extent of colloidal Ca phosphate cross-linking between casein micelles due to increased Ca content (Singh and Muthukumarappan, 2008). Other positive influence of calcium salts on the properties of yogurt reported by some authors is the increase in the water holding capacity in comparison to controls (Singh and Muthukumarappan, 2008; Shamsia, 2010). In order to improve the solubility properties of salts and avoid textural defects, the use of micronized tricalcium citrate seems to be an excellent alternative for their unique characteristics: is more soluble at low temperatures, shows improved solubility at pH-values below 4.5, and can be suspended in dairy products at high levels without negative taste effects, among others (Münchbach and Gerstner, 2010). Likewise, the addition of nanoparticulized salts to yogurts has been recently reported, and the preliminary results seem to show advantages of the use of nanoparticles over conventional fortification (SantillánUrquiza et al., 2017). A few studies have addressed the influence of fortification on microbial counts. Some researchers observed a significant increase in the numbers of LAB in yogurts fortified with calcium lactate (Pirkul et al., 1997) and calcium gluconate (Yonis et al., 2013), whereas others reported that the microbial growth decreased in calcium phosphate fortified yogurt or showed no differences in calcium citrate yogurt as compared with controls (Kaushik and Arora, 2017). Several studies about fortification with other minerals have been published recently. It is well known that dairy products are poor sources in iron, zinc, and other minerals; however, they are among the vehicles most chosen for mineral fortification (Drago and Valencia, 2002). Fortification with iron is technologically challenging since iron can easily react with several food ingredients, catalyzing oxidative reactions that cause color and flavor changes. Thus, the quality of iron-fortification dairy products depends on the levels and sources of iron and properties of the carrier dairy products (ElKholy et al., 2011; Askary and Bolandi, 2013). For this reason, the effect of added iron on quality parameters of yogurt such as microbial counts, fat oxidation, taste, shelf life, and overall acceptance must be exhaustively assayed. Two principal off-flavors found in fortified yogurt are oxidized and metallic notes, which are due to the catalytic role of iron and the presence of iron salts, respectively (Gahruie et al., 2015). Successful attempts to add different chemical forms of

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iron to ­yogurts have been reported (Hekmat and McMahon, 1997; Askary and Bolandi, 2013; Simova et  al., 2008). However, in order to reduce the apparent organoleptic problems, microencapsulation of iron is one of the best approaches (Gupta et al., 2015; Kim et al., 2013; Nkhata et  al., 2015; Subash and Elango, 2015). On the other hand, the iron source used for food fortification is a key factor for its bioavailability. Iron-fortified yogurts have a relatively high iron bioavailability (Gahruie et al., 2015).The use of nano-sized iron and zinc for yogurt fortification showed more solubility than micro-minerals in in vitro digestion analysis, with minor changes in physicochemical, sensorial, and rheological parameters of the products (SantillánUrquiza et al., 2017). Some studies indicate that milk fermentation or acidification caused an increase in iron and zinc availability when yogurts were fortified with ferrous sulfate and iron bis-glycinate (Drago and Valencia, 2002).

6.4.5 Peptides Nowadays, it is well recognized that several proteins could contribute to human health through their latent biological activities. In effect, certain peptides encrypted in the primary sequence of the native protein become physiologically active after their release by the activity of different proteolytic and peptidolytic enzymes; they are termed as “bioactive peptides” (Korhonen and Pihlanto, 2006). The release of these compounds may occur in  vivo during digestion of the parent protein in the gastrointestinal tract, in situ during food processing, or in vitro by enzymatic hydrolysis (Marcone et al., 2017). Bioactive peptides have a beneficial impact on body functions or conditions (Marcone et  al., 2017). Numerous and specific health-­ promoting properties have been demonstrated: antihypertensive, antioxidative, antithrombotic, hypocholesterolemic, opiod, ­mineral-binding, antiappetizing, antimicrobial, immunomodulatory, and cytomodulatory (Korhonen and Pihlanto, 2006). Milk proteins, both caseins and WPs, constitute the main source of physiologically active peptides, named as casokinins and lactokinins, respectively. In fermented milks, the presence of bioactive peptides is mainly due to their in situ liberation from the parent protein during the food processing (fermentation and storage) by the proteolytic activity of the cultures used (Fitzgerald and Murray, 2006; Sah et al., 2016a, b). The combination of proteolytic starter cultures and an exogenous protease was also evaluated for the preparation of fermented dairy beverages in order to increase the levels of biopeptides. In addition, other strategy consists of the supplementation of the milk base with protein hydrolyzates obtained with food-grade enzymes such as gastrointestinal enzymes (pepsin, trypsin, chymotripsin) or microbial

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enzymes (thermolysin, alcalase) (Korhonen, 2009; Choi et  al., 2012; Hafeez et al., 2014; Marcone et al., 2017). Among bioactive peptides identified in dairy beverages, those with antihypertensive activity due to the inhibition of the ­angiotensin-converting enzyme (ACE) are the most widely studied (Fitzgerald and Murray, 2006). Some products are commercially available: Calpis (Calpis Co., Japan) sour milk, a Japanese milk fermented by Lactobacillus helveticus CP790 and Saccharomyces cereviseae, contain ACE-inhibitory (ACE-I) peptides; Evolus (Valio Oy, Finland) fermented milk drink, produced with L. helveticus LBK16H, contains the potent hypotensive casein-derived tripeptides Ile-Pro-Pro (IPP) and Val-Pro-Pro (VPP). The antihypertensive activity of these products was verified in in vivo tests using hypertensive rats and human subjects (Nakamura et al., 1995; Seppo et al., 2002; Jauhiainen et al., 2005; Korhonen and Pihlanto, 2006; Choi et al., 2012). In addition to commercial products, several research articles have been published about the production of ACE-I peptides in fermented milks. Donkor et al. (2007) found that the incorporation of probiotic bacteria (L. casei L26, Bifidobacterium lactis B94 or L. acidophilus L10) in yogurt led to an increase in the proteolysis, which was jointed with an increase in the level of ACE-I peptides. Several peptides derived from casein were identified as responsible for the antihypertensive activity demonstrated in in vitro assays. Gonzalez-Gonzalez et al. (2011) found that several probiotic strains were able to produce ACE-I peptides in fermented milk; L. casei YIT 9029 and B. bifidum MF 20/5 produced the highest proteolysis and potency of the ACE-I activity. A novel ACE-I peptide LVYPFP [β-CN (73–78)] was reported for first time in the fermented milk produced with B. bifidum MF 20/5; in addition, other ACE-I peptide such as LPLP and the antioxidant VLPVPQK [β-CN f(170–176)] were also found, but nor IPP neither VPP were identified (Gonzalez-Gonzalez et al., 2013). The β-casein (f114-121) peptide, reported as having both antihypertensive and opiod activities, was identified in Greek sheep milk yogurt, produced with L. delbrueckii subsp. bulgaricus Y10.13 and S. thermophilus Y10.7, with and without the addition of a probiotic strain (Papadimitriou et al., 2007). Kilpi et  al. (2007) studied the ACE-I activity of milk fermented by the peptidase-negative mutant of L. helveticus compared with that fermented by the wild-type strain, in order to evaluate the influence of the peptidases (PepN and PepX) on the production of bioactive peptides. They demonstrated that the peptidase-negative mutant of L. helveticus resulted in increased level of ACE-I activity. Pihlanto et  al. (2010) found that the ability to increase the ACE-I activity in an in vitro assay by 25 strains of LAB was strain dependent and, for some strains, this capacity was correlated with the degree of proteolysis. The milk fermented with Lactobacillus ­jensenii

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showed the highest bioactivity and the hypotensive peptides identified in the product were β-CNf(11–26) and β-CNf(11–20). Chaves-López et  al. (2014) evaluated the production of ACE-I peptides in Kumis, which is produced by fermentation with LAB and yeasts. They studied individual strains (four strains of different yeasts, two strains of L. plantarum, and Enterococcus faecalis KE06) and different combinations of them. The combination of Pichia kudriavzevii KL84A, L. plantarum LAT3 and E. faecalis KL06 led to a product with the highest ACE-I activity and without a bitter taste; bitter taste is a defect that could appear due to the increased proteolytic activity. In relation to the combination of LAB and exogenous protease to increase ACE-I peptides, Tsai et  al. (2008) obtained 5.6 fold higher levels of ACE-I peptides by means of the incorporation of commercial protease (Flavourenzyme) during yogurt making, and the bioactivity of the product was mainly attributed to the peptide Tyr-Pro-Tyr-Tyr. Sah et  al. (2016a, b) evaluated the influence of fermentation conditions on the release of ACE-I peptides in yogurt fermented by L. helveticus, added or not with Flavourzyme. Peptides with the highest ACE-I activity were obtained when the fermentation was carried out with an inoculum of 4% (v/w) during 8 h without the incorporation of Flavourzyme, and an inoculum of 1% (v/w) during 12 h with the addition of Flavourzyme. Apart from antihypertensive activity, several other bioactivities have been detected in fermented milk. Farvin et al. (2010a, b) found that peptide fractions isolated from yogurt had antioxidant effects, which was associated to the presence of peptides derived mainly from β-casein and some N-terminal fragments from αs1-, αs2, and Ƙ-casein, and free amino acids. Sah et al. (2014) demonstrated that the addition of three probiotic bacteria, both as individual and mixed cultures, increased the levels of proteolysis of yogurts, which correlated with a higher production of peptides with antioxidant and antimutagenic activities; the greater changes were obtained in the yogurt with the mixed culture. Two mesophilic lactobacilli strains isolated from cheeses and which had high proteolytic activity: L. casei PRA205 and L. rhamnosus PRA331, were tested in fermented milk. L. casei PRA205 showed the highest ACE-I and radical scavenging activities, and concentration of antihypertensive peptides (IPP and VPP) (Solieri et al., 2015). The fermentation of milk by L. helveticus LH-2 released peptides derived from β-casein and α-lactalbumin that were capable of modulating macrophage activity in in vitro assays (Tellez et al., 2010). De LeBlanc et al. (2005) demonstrated that the milk fermented by L. helveticus R389 had inmunoregulatory capacity on the immune response in mammary glands and tumor in in vivo assays using a model of breast cancer in mice. This bioactivity was mediated by substances released

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during fermentation, possibly peptides produced by the strain, which had a high proteolytic activity. Casein phosphopeptides (CPP) are derived from casein by hydrolysis mainly with digestive enzymes. Multifunctional bioactive effects have been attributed to CPP such as antiocariogenicity, antioxidant, and mineral binding capacity (Korhonen and Pihlanto, 2006). Lorenzen and Meisel (2005) obtained a yogurt with an increased amount of CPP by the action of trypsin that was added to the milk and let it act before the fermentation. Our research group applied a similar approach for the production of CPP in yogurt. We found increased proteolysis in this product, and higher levels of CPP; we also demonstrated higher anticariogenic activity in hydrolysated yogurts in comparison to controls (Bergamini et al., 2015). Ebner et  al. (2015) evaluated the peptide profile of bovine kefir and determined that 16 peptides released during its production were previously described as possessing different activities: ACE-I, antithrombotic, mineral binding, antimicrobial, immunomodulating, and opiod. Moslehishad et  al. (2013) found that L. rhamnosus PTCC 1637 ­produced higher level of peptides with ACE-I and antioxidant activities in camel milk in comparison with bovine milk, which was attributed to structural differences of proteins and the higher content of Pro in casein from camel milk. In addition, Politis and Theodorou (2016) reported higher ACE-I and immunomodulatory activities in Greek yogurt made with ovine milk than that with bovine milk. Quirós et  al. (2005) detected ACE-I properties in kefir made from caprine milk; the most potent activity was observed for two peptides: PYVRYL and LVYPFTGPIPN. The composition and ingredients of the milk base used for the fermented milk production could modify the viability and proteolytic activities of the cultures added (Kenny et  al., 2003; Sah et  al., 2015a, b), and hence affect the production of biopeptides. In this way, the supplementation of probiotic yogurts with prebiotics (pineapple peel powder or inulin) increased the proteolysis and the production of inhibitory peptides against pathogens bacteria and antimutagenic and antioxidant peptides (Sah et al., 2015a, b; Sah et al., 2016a, b). On the other hand, the fermentation of 10% (w/w) RSMP with 5% (w/w) added sodium caseinate by two strains of L. helveticus led to a higher levels of ACE-I activity in comparison with the use of 12% (w/w) RSMP or 10% (w/w) RSMP with 5% (w/w) added WP isolate (Leclerc et al., 2002). On the other hand, it is important to evaluate the stability of biopeptides in the food matrix, as they can be hydrolyzed by proteolytic enzymes during storage of the product or during passage through the gastrointestinal tract; this fact could modify their biologically activity. Sah et al. (2016a, b) verified a substantial diminution of the inhibitory

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activities against Escherichia coli and cancer cells during in vitro gastrointestinal digestion of probiotic yogurts. The ACE-I activity of the most peptides found in a commercial kefir from caprine milk was similar or slightly lower after simulated digestion (Quirós et al., 2005). On the contrary, the peptides VPP and IPP, and other β-casein-derived bioactive peptides have demonstrated to be resistant to digestive enzymes, and so, these peptides retain their bioactivity until adsorption (Ohsawa et al., 2008). On the other hand, an increase of the bioactivity after the gastrointestinal digestion was also reported; the peptides were hydrolyzed into fragments with higher activity that of the parent peptide (Gonzalez-Gonzalez et al., 2013; Quirós et al., 2005). A comprehensive database about bioactive peptides derived from milk protein of different mammalian species reported in hundreds of research articles has been compiled by Nielsen et al. (2017). This information will be very useful to compare new peptides to previously discovered in order to identify their potential bioactivities.

6.5  Reduction (or Replacement) of Food Components 6.5.1 Lactose Reduction Lactose (β-d-galactosyl-d-glucose) is practically the only sugar present in mammal milks; its concentration in cows’, buffalos’, and goats’ milks is approx. 4.8 g/100 mL and in sheeps’ milk is slightly lower (approx. 4.1 g/100 mL) (Fox, 2011). From a nutritional point of view, lactose is the most important source of energy during the first year of human life (Vesa et al., 2000). Besides, stimulates the growth of bifidobacteria in the gut and supplies galactose that is an essential nutrient for the formation of cerebral galactolipids (Mlichová and Rosenberg, 2006), and acts as carrier of minerals through ligand-­ formation facilitating their absorption (Schaafsma, 2008). Under normal conditions, the lactose is easily absorbed in the intestine after conversion to its monosaccharide moieties (glucose and galactose) by the β-­galactosidase enzyme (β-d-galactoside galacto-hydrolase, E.C. 3.2.1.23) (also called lactase), which is anchored to the brush border membrane of the small intestine mucosa (Mahoney, 2003; Schaafsma, 2008; Ingram and Swallow, 2009). After weaning, a genetically programed reduction in lactase activity can happen and a limited hydrolysis of lactose occur. When high levels of lactose reaches large intestine cause disorders such as diarrhea, abdominal pain and cramps, bloating, gas formation (flatulence), nausea, and loss appetite (Bayless et al., 2017; Corgneau et al., 2017). This problem is known as lactose intolerance and affects 70% of the world population.

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Some studies have shown that lactose digestion improves with the consumption of fermented milk compared with milk. However, yogurt may contain lactose levels comparable with milk depending on the composition of the milk base and the acidification activity of starter cultures. In fact, Batista et al. (2008) found lactose values from 3.01% to 4.95% for 110 yogurt samples belonging to 22 commercial brands; Ohlsson et al. (2017) detected levels from 2.9 to 3.6 g/100 g of lactose for different varieties of yogurts and fermented milks. The best tolerance of fermented milk comparatively with milk may be due to the semisolid consistency that slows the gastric emptying and favors the lactose hydrolysis by β-galactosidase activity (Shah, 2006). However, some authors suggest that fermented milks could be harmful for individuals with elevated degree of intolerance (Batista et  al., 2008; Shaukat et al., 2010). For this reason, individuals suffering lactose intolerance sometimes leave to consume dairy foods to avoid the annoying symptoms. Taking into account that dairy products are a source of valuable macro and micronutrients, alternatives to reduce or remove the lactose can be employed in order to intolerant people continue the intake of dairy foods (Mlichová and Rosenberg, 2006; ShakeelUr-Rehman, 2009). The interest of dairy industries for providing the consumers reduced lactose or free-lactose fermented milks has progressively increased mainly stimulated by the acquired knowledge in relation to the awareness of the lactose intolerance problem. In this context, the potential market for this type of products has been growing steadily (Saxelin et al., 2003; Shakeel-Ur-Rehman, 2009). Reduced or lactose-free fermented milks are commercialized in several countries, but not yet in Argentina. Different technological processes are employed: enzymatic hydrolysis with β-galactosidase (soluble or immobilized enzymes) and physical processes of separation such as ultrafiltration and chromatography (Shakeel-Ur-Rehman, 2009); the first one is the most widespread. The enzymatic treatment can be applied in a preincubation step of the milk base before starter addition or simultaneously during fermentation. β-Galactosidase splits the lactose into glucose and galactose. The levels of glucose, galactose, and lactose in the fermented products will depend on the content of lactose of the milk base, the type and doses of enzyme used and the metabolic activity of the starter. Nevertheless, the modification in the carbohydrate profile by β-­galactosidase enzyme treatment could influence the metabolic activities of the starter affecting the fermentation process, the production of compounds, and thus the characteristics of final product. Martins et al. (2012) reported a reduction in the fermentation time for probiotic (B. animalis and L. acidophilus) yogurts in which the lactose hydrolysis with β-galactosidase enzyme from Kluyveromyces lactis and Aspergillus niger (Lactomax Flex) and fermentation were

Chapter 6  Production of Functional Milk-Based Beverages   209

carried out simultaneously, in comparison to yogurts without enzyme addition. A reduction in viscosity and an increase in syneresis as the enzyme concentration increased from 0.5 to 1.0 g/L were detected. The minimum residual lactose content in the hydrolyzed yogurt was 0.19 g/100 mL. Contrary, Ibarra et al. (2012), Vénica et al. (2014), and Moreira et al. (2017) found longer fermentation times for hydrolyzed yogurts in relation to nonhydrolyzed products. Vénica et  al. (2014) used a β-galactosidase enzyme from K. lactis (GODO YNL-2) added simultaneously with starter culture in the preparation of drinkable and stirred, natural, and sweetened yogurts. Lactic acid content was lower in hydrolyzed yogurts comparative with unhydrolyzed products, and this effect was more marked in sweetened yogurts. The range of residual lactose contents for the different yogurt varieties was from 0.33 to 1.54 g/100 mL, depending on the lactose content of the milk base. The LAB concentration at the end of process and its evolution during storage were similar between hydrolyzed and nonhydrolyzed yogurt. This fact indicated that although there was a change in the carbohydrate composition, it did not affect the grown and viability of starter cultures. Moreira et al. (2017) found higher lactic acid in yogurt made from hydrolyzed milk (0.19 g/100 g of lactose) than that made with traditional milk (4.43 g/100 g of lactose); hydrolyzed yogurts had a lactose content ≤0.10 g/100 g. The addition of sugar and carob diminished the production of lactic acid. Ibarra et al. (2012) noted an increase in the fermentation time during making of probiotic (L. rhamnosus HN001) yogurt as the lactose hydrolysis percentage increased. The diminution in lactose content favored the L. rhamnosus HN001 growth in the hydrolyzed yogurt and lowered its overall quality. Cutrim et  al. (2016) employing traditional milk (4.46 g/100 mL of lactose) to manufacture yogurt took 5.5 h and with lactose hydrolyzed milk with 1.53 and 0.60 g/100 mL of lactose took 4.5 and 6.5 h, respectively. Minor lactic acid content was detected only for hydrolyzed yogurt made with milk containing 0.60 g/100 mL of lactose, compared with yogurt made with traditional milk. Residual lactose content ranged from 0.47 to 0.88 g/100 mL and from 0.27 to 0.30 g/100 mL for the yogurt made with the highest and lowest lactose content in the milk, respectively. They suggested that the lower fermentation time observed in fermented milks made with intermediate content of lactose could be explained by the presence of higher amounts of glucose and galactose in the medium, compared with traditional fermented milks, which are more readily used by LAB. Meanwhile, the delay in the fermentation process observed when the amount of lactose in milk is low could be due to the partial inhibition of the lactose transports system into cells. On the other hand, Schmidt et al. (2016) used five different starter cultures in the preparation yogurts and fermented milk from hydrolyzed lactose milk (G″). As compared with plain yogurt, stirred yogurt has a relatively weaker viscoelastic network arising from interactions between casein aggregates, whey proteins, and milk-fat globules. This is because yogurt drinks are usually prepared by homogenization of acid casein gels. Electron microscopy observations show that stirred yogurt has fewer chains and more clusters of casein micelles joined together by fibers (Kalab, 1979). As done in acidified milk drinks, stabilizers are also added to various types of yogurts. The type of stabilizer used has a marked influence on the rheological behavior of milk beverages. For example, drinking yogurt stabilized using pectin was found to be shear thinning whereas those stabilized by carboxy methyl cellulose (CMC) were found approximately close to Newtonian behavior. Lobato-Calleros et al. (2014) studied the rheological behavior of reduced-fat yogurts with the help of Cross equation, and concluded that addition of native or chemically modified starches to reduced-fat yogurts yielded stable acidified milk gelled systems. Similarly, Glibowski and Rybak (2016) studied the effect of inulin on the rheological characteristics of stirred yogurt, and concluded that yogurt showed shear-thinning behavior with characteristic hysteresis loops regardless of its composition. Vélez-Ruiz et al. (1997) consolidated the work done on rheological characterization of various yogurts (Table 11.3).

11.3.2.2 Lassi Lassi is an important fermented milk beverage of India. It is the viscous liquid obtained after churning of fermented milk (dahi) and adding sugar into it. Therefore, lassi has a characteristically sweet and sour taste. Fresh raw milk is used for its preparation. However, lassi with only 6%–9% TS and heavy aggregated proteins have the tendency to undergo sedimentation, causing syneresis or wheying off.

Table 11.3  Rheological Characterization of Yogurt (Vélez-Ruiz et al., 1997) Experiment

Instrumentation

Findings

Rheological and structural characteristics of ropy and nonropy yogurt

Haake Rotovisco RV2 viscometer

Rheological analysis of yogurt using flow and dynamic properties

Rheometrics Mechanical Spectrometer RDS II and Carri-Med CS 100 rheometers Posthumus funnel, penetrometer and rotational viscometer Texture analyzer

Viscosity of ropy yogurt was three times higher than non-ropy yogurt. Both types of yogurt showed a peak shear stress, 150 Pa for ropy and 50 Pa for non-ropy yogurt Yogurt showed thixotropic character. At low strains, yogurt was primary elastic, but at high strains it became viscous

Rheological characterization of yogurt Effect of temperature of ultrafiltration on the structure and rheology of Labneh Stevens Physical properties of yogurt affected by proteolytic treatments Rheological properties of yogurt made from two types of milk Rheological measurements of structural changes in yogurt Viscoelastic properties of yogurt as affected by starter culture Effect of starter cultures on linear viscoelastic properties of yogurt Stirred yogurt Viscosity of stirred yogurt

Rheological properties of yogurt as affected by temperature

Rheological properties of stirred yogurt as affected by flavoring ingredients Rheological characterization of yogurt as affected by ingredient composition

Brookfield RVT viscometer Bohlin VOR rheometer Bohlin VOR rheometer Rheotech International rheometer Rheometrics ES rheometer and Instron Universal Testing Machine Deer rheometer, Posthumus funnel and Tube viscometer Haake Rotovisco RV20

Haake Rotovisco RV20 rheometer Haake RV20 rheometer

Viscosity of ropy yogurt was at least two times higher than that of non-ropy yogurt Firmness was affected by the method of production, process temperature, and homogenization Firmness and apparent viscosity of yogurt were influenced by extent of proteolysis Rheological characteristics differed significantly between skim milk and ultrafiltered retentate Structure breakdown and rheological changes during viscoelastic tests were analyzed Elasticity of yogurt was not affected by secreted polysaccharide. The moduli for ropy yogurt decreased during storage Inverse relationship between G' and tan δ was observed

Yogurt had yield stress. Modified power law was used Flow curves were described by Herschel-Bulkley model. Rheological properties and temperature were fitted respectively by Arrhenius and Turian relationships Thixotropic flow behavior with yield stress was observed. Pectin and raspberry concentrate affected the flow behavior index Thixotropic flow was fitted by Weltman equation. Ingredients had a significant influence on rheological properties

386  Chapter 11  Rheological Properties of Milk-Based Beverages

The rheological behavior of lassi is affected by TS, sugar contents, stabilizer type, and its concentration (Saraswat, 2011). Of all factors studied, TS seemed to have the highest influence on the rheological behavior of lassi. Increase in concentration of TS was accompanied by increase in pseudoplasticity, consistency coefficient, and yield stress. In contrast, sugar content had a negative influence on the rheological behavior. Carrageenan, pectin, and locust bean gum (LBG) were used as stabilizers. Amongst them, carageenan at 0.15% was the most suitable for lassi. LBG-added samples showed visible whey separation owing to precipitation of milk proteins, and hence, it was not recommended to stabilize lassi. Phase separation was largely attributed to the incompatibility of micellar casein and LBG. The rheological behavior of lassi was better described by the Herschel-Bulkley and Casson models.

11.3.2.3 Doogh Doogh is a native beverage of Iran. It is an acidic dairy drink with pH close to 4, and is prepared by churning and dilution of yogurt, with addition of salt and flavorings. It is similar to the Turkish product, ayran. The colloidal aggregates of proteins decide the rheological behavior of doogh. This drink is particularly unstable because the extent of dilution is greater than that of yogurt-based beverages, including ayran. Kiani et al. (2008) explored the effects of gellan gum and high-methoxy pectin (HMP) on the structure and stability of doogh. Addition of HMP alone showed satisfactory storage stability for approximately10 days at refrigerated conditions. In contrast, doogh added with gellan showed rapid development of a clear serum phase, suggesting expulsion of water due to contraction of the gel network. Azarikia and Abbasi (2010) reported that the rheological model for normal doogh was Newtonian while those stabilized with gum tragacanth exhibited non-Newtonian behavior, which followed Power law model. Laban is also a similar fermented milk beverage. Lactic acid, which is the main metabolite of fermentation, imparts laban the typical sharp and acidic taste. The microstructure of laban is very similar to other fermented beverages. It consists of the protein matrix containing aggregated casein miscelle chains surrounding the fat globules. Therefore, laban also exhibits both thixotropic and shear thinning behaviors. The rheological and textural parameters are major quality attributes of laban. Chammas et al. (2006) measured the rheological properties of 96 fermented milks made from bacteria isolated from laban. The apparent viscosity varied from 0.11 to 0.32 N while the complex viscosity ranged widely between 0.24 and 12.63 N (Hui and Evranuz, 2012).

Chapter 11  Rheological Properties of Milk-Based Beverages    387

11.3.2.4  Whey-Based Beverages The second most important group of proteins in milk is the whey proteins. They are widely employed as a major ingredient in sports supplements. Therefore, a number of beverages are available in the market that utilizes whey proteins as major ingredient. In particular, lactic fermented beverages containing milk, yogurt, whey, and fruit pulp are formulated and are commercially available in many markets. The main difference between yogurt and fermented dairy beverages is the addition of whey to the latter, which results in lower viscosity. However, these lactic beverages are classified as fermented milks because of their low acidity level. Also, their microbiological profile is similar to that of yogurt. The relationship between physicochemical and rheological properties of five commercial lactic beverages was studied by Penna et al. (2001). All the lactic beverages manifested non-Newtonian behavior with thixotropy. As these beverages had no yield stress, Power law model was more suitable than Herschel-Bulkley model to describe their rheological behavior. Debon et  al. (2010) proposed Power law and Mizhari and Berk models to describe the flow of fermented milks containing inulin, which had characteristics of shear thinning and non-Newtonian fluid behavior. Similarly, Castro et al. (2013) reported that probiotic milk beverages containing whey and milk presented thixotropic and pseudoplastic behaviors. Increasing concentration of whey in the beverages increased the flow behavior index and decreased the consistency coefficient. These reports suggest that the lactic beverages do not have yield stress. The yield stress disappears because increasing the whey content in beverages increases the fragility of the gel structure due to the replacement of caseins by whey proteins.

11.3.3  Microstructure and Storage Stability of Milk Beverages Microstructure of dairy beverages is important because of its influence on rheological properties under different processing conditions. Electron microscopy is widely used to study the microstructure of dairy beverages. It throws light about the interactions between milk components during formation of matrix, particularly in fermented dairy beverages. UHT milk is stable for long-term storage at ambient conditions. However, during storage of UHT milk, association and disassociation of proteins may continue due to chemical and biochemical interactions. Gelation occurs and the molecular weight of the casein micelles increases. In contrast, the structural components in fermented milks

388  Chapter 11  Rheological Properties of Milk-Based Beverages

differ from that of milk. They consist of fat globules, water, colloidal protein aggregates, and additives such as stabilizers. The two milk components responsible for structural changes in fermented dairy beverages are casein and milk fat. Although fermented products such as yogurt, lassi, etc. have same level of solids and moisture as that of milk, they behave like solid gels due to change in the structure of casein micelles during fermentation. The solidity is due to aggregation of casein micelles and formation of a three-dimensional (3D) network. Set yogurt has a firm gel like structure but in stirred or drinking yogurt, the protein network is broken into small aggregates after it has been formed and the protein matrix is less dense as compared with set yogurt (Tamime, 2008). The microstructure of low-fat yogurts prepared with microfluidized milk comprises of smaller and more even fat globules, well distributed into more interconnected fat protein gel networks, compared with those of control yogurt. Microfluidization at pressures of 50–150 MPa increased the gel strength by 171%–195% and viscosity by 98%–103%, creating low-fat yogurts with creaminess and desirable textural properties similar to or better than full-fat conventional yogurt (Ciron et al., 2012). Storage stability is an essential requirement in the development of milk beverages. Proper storage helps to maintain quality of the product by retaining flavor, texture, consistency, etc. Gelation and sedimentation are important quality parameters of UHT milk, which reduce its shelf life. In contrast, the stability of acidified milk beverages is evaluated on the basis of viscosity, the amount of sedimentation, and microstructural examination of the proteins fractions. Topçu et al. (2006) investigated the storage stability of UHT milk in terms of extent of proteolysis. The authors confirmed that UHT milk processed from low-quality milk led to gelation. Fermented dairy beverages are better preserved than the liquid milk. However, during storage of fermented milks, the gel-like network gets gradually destroyed because the casein network gets disturbed, weakened, and broken. These disturbances in stability occur due to decrease in pH and increase in acidity and syneresis. Mani-López et al. (2014) evaluated the physicochemical properties such as texture, and syneresis during fermentation and storage of yogurts and fermented milks. Only yogurt with S. thermophilus, L. delbrueckii ssp. bulgaricus, and Lactobacillus reuteri differed in firmness. Syneresis was in the range of 45–58%. However, yogurt and fermented milk made with Lactobacillus casei were better accepted. Digambar et  al. (2017) studied the effect of incorporation of encapsulated and free Arjuna herb on storage stability of sterilized chocolate and vanilla milk beverages at room temperature. Viscosity and sedimentation stability of the beverages containing encapsulated Arjuna herb were

Chapter 11  Rheological Properties of Milk-Based Beverages    389

better than that of control during storage, and the herb was effective in enhancing the storage stability of these non-fermented beverages.

11.3.4 Effect of Additives and pH on Rheological Properties of Milk Beverages 11.3.4.1  Effect of Hydrocolloids Hydrocolloids are very minute hydrophilic materials, natural or synthetic, that swell when added to water. They significantly influence the rheological behavior of dairy beverages. Hydrocolloids are used in dairy products for a variety of purposes including thickening and improving mouthfeel. Tamime and Robinson (1999) stated that it was essential to add stabilizers at suitable concentrations to improve the quality of fermented milk products and standardize the TS content. The mechanisms of action of hydrocolloids may be viscosifying, gelling, and complexing. The hydrocolloid molecules form a network of linkages with the milk constituents, owing to the presence of negatively charged groups such as hydrogen or carboxyl radicals, or due to the presence of a salt possessing the power to sequester calcium ions. Formulation of low calorie beverages thus increased the use of hydrocolloids as they can help to suspend the solids and maintain the mouthfeel in such beverages. In milk-polysaccharide systems wherein milk proteins and hydrocolloids coexist, it is important to understand the mechanisms, interactions, and synergistic effects that can provide maximum beneficial effect to the food product. For example, carrageenans and starches are used extensively to gel dairy products as they are able to stabilize and gel milk proteins even at low doses. Pectin is also widely used in fermented milks to circumvent the problem of phase separation. The concentration of pectin required to ensure stability in acid milk systems is about 0.1%–0.5%. Pectin gets electrosorbed to the protein particles, and prevents the flocculation of proteins by steric hindrance. It protects the protein after homogenization and prevents reaggregation of proteins that leads to whey separation (Olsen, 2003). Other stabilizers also interact with caseins by various mechanisms, thereby altering the rheological properties of these beverages. Wu et al. (2013) reported that acidified milk beverages could be stabilized by CMC, which was capable of effectively preventing unwanted creaming of fat embedded in the clusters of CMC and caseins, and reduce the aggregation of casein micelle. While the stability of fermented milk beverages is enhanced with the incorporation of stabilizers, the degradation of stabilizers such as CMC in low pH environment and complex protein-polysaccharide interactions also give rise to instability of the final products.

390  Chapter 11  Rheological Properties of Milk-Based Beverages

Pang et al. (2015) studied the rheological behavior of milk proteins at different stages. During acidification at 45°C, lower storage modulus (G′) was observed in the presence of 1% gelatin. However, during cooling and annealing stages (at 10°C), the G′ of the gels increased due to gelation. Higher concentration of gelatin led to formation of strand-like structures. During the heating stage (from 10°C to 45°C), gelatin strands were melted and the G′ of the mixed gels decreased to the value of acidification stage, indicating that the changes caused by gelatin in the microstructure of milk protein gels were reversible. In addition, gelatin enhanced the water holding capacity of the gels without increasing the firmness of the gel significantly. Buldo et  al. (2016) studied the microstructure and texture of acidified milk by adding low and high acyl gum with different casein to whey protein ratios. Low acyl gum exhibited a continuous gel network while separation of microphase was observed with high acyl gum. The continuous gel network was indicative of complexation between polysaccharides and casein, which in turn led to enhanced textural properties and reduced syneresis. While pectin is widely used in stabilization of acidified milk beverages, carrageenan is commonly used in non-fermented milk systems such as gels, puddings, etc. This is because carrageenan possesses high degree of reactivity with milk protein. This reaction with casein is called “milk reactivity,” and it aids in its application as a good suspending and stabilizing agent. In contrast to its behavior in fermented milks, addition of pectin to milk at its normal pH can cause phase separation into casein-rich and the other protein-rich layers. Thus, pectin reduces the colloidal stability of micellar casein at neutral pH observed in milk. Yanes et  al. (2002) concluded that milk containing 0.01%–0.05% of κ-carrageenan showed pseudoplastic flow. A sharp increase in pseudoplasticity and viscosity was observed at κ-carrageenan concentrations above 0.3%. On the contrary, no marked change in pseudoplasticity of milk was observed even at higher concentrations of sodium alginate. This is because the microstructure of gels made using low dosage of carrageenan becomes extensively flocculated with large aggregates (Arltoft et al., 2007). Similarly, at temperature beyond the gelation temperature, the phase angle values of β-carrageenan-based systems were less than 45 degree (tan δ V’m

E

(C)

Medium

Fig. 12.2  Schematic diagram of a cell membrane breakdown (Zimmermann, 1986). (A) The membrane is analogous to a dielectric filled capacitor (hatched area). V ’m = normal resting potential difference across the membrane (~ 10 mV). (B) The cell membrane is exposed to an electric pulse of filed strength (E) which causes built-up of potential difference across the membrane (V), which is a function of both E and cell radii. This causes a compression of cell membrane thickness. (C) When the membrane potential difference reached a critical value (Vc), membrane breakdown or poration is initiated. This leads to immediate discharge of membrane potential and consequent decompression of membrane thickness (hence reversible if pore size negligible in comparison to total membrane surface). (D) As filed strength and exposure times increase, the pore size also increases, causing irreversible breakdown of membrane and destruction of the cell.

–

E become too large, large Pores (Irreversible)

breakdown of cell membrane has also been explained based on its viscoelastic properties by constructing a physical model equivalent to the three-element Maxwell fluid model. Properties such as surface tension and viscosity of membrane were incorporated in the model to determine the critical breakdown potential (Barbosa-Canovas et al., 1999).

12.2.2 Working Food to be treated is placed in the treatment chamber which can be either in a static or continuous design, where two electrodes mainly constructed of stainless steel, inert carbon aluminum, gold-plated

Chapter 12  Nonthermal Processing of Dairy Beverages   401

electrodes, and even silver electrodes (Barbosa-Canovas et al., 1999) are connected together with a nonconductive material. Electrodes are designed to minimize the effect of electrolysis (Barbosa-Canovas et  al., 1999). Normally four types of wave forms namely triangle, rectangular, square, and exponential decay pulse are generated by pulse-forming network. An exponential decay voltage wave rises rapidly in a unidirectional voltage to a maximum value and decays slowly to zero. As compared to all other shapes, square pulse waveforms are more lethal and more energy efficient than exponential decaying pulses.

12.2.2.1  Processing Equipment PEF system for food processing, in general, consist of three basic components: a high-voltage pulse generator for generation of the electric pulses, a treatment chamber for holding the food sample while it is being subjected to the high voltage and a well-designed control system for monitoring the process parameters (Loeffler, 2006).A PEF generating system may have a storage capacitor bank, a charging current limiting resistor and switches to discharge energy from the capacitor to the foods. High-voltage and high-current probes are used to measure the voltage and current delivered to the chamber (BarbosaCanovas et  al., 1999). High-density capacitors and solid-state power devices have been successful in achieving considerable reduction in overall size of equipment. Apart from these major components, auxiliary equipment such as pump (in continuous-type system) and cooling system also form necessary components of the complete unit. An electrical circuit consisting of one or more power supplies with the ability to charge voltages (up to 60 kV), switches (ignitron, thyratron, tetrode, spark gap, semiconductors gate turn off (GTO) thyristor, the insulated gate bipolar transistor (IGBT), and the symmetrical gate commutated thyristor (SGCT), capacitors (0.1–10 μF), and resistors (2–10 MΩ) modulate the supply of desired power to the treatment chambers (Mohamed and Eissa, 2012).

12.2.3 Applications Even though in recent times, PEF technology has found alternative applications as an adjunct technology for enhancement of drying rates, modification of enzyme activity, improvement of metabolite extraction, biotechnology, and genetic engineering application of electroporation in cell hybridization, etc. (Mohamed and Eissa, 2012). The primary focus of the application of PEF technology in food industry remains as a viable alternative to the traditional thermal pasteurization processes for the preservation of solid and semisolid food products. Many studies have demonstrated the feasibility of PEF technology to

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produce safe, fresher, and nutritious foods covering a wide range of liquid matrices such as milk and milk products. Most of reports are focused on the effect of PEF treatments on the microbial inactivation in milk, yogurt, soups, eggs, water, beer, juice, etc. (Juan et al., 2012; Pal, 2017; Gamli, 2014; Sampedro et al., 2013). The dairy industry is an important sector of food processing and a great part of the PEF research reported in the literature is focused on evaluating its effect on milk and dairy products. Milk being a perishable commodity and an active medium for growth of microbes, most of the studies carried out with these products have been performed to evaluate the effect of PEF treatment on microbial inactivation. Bermudez-Aguirre et  al. (2011) evaluated the physicochemical characteristics and shelf stability of PEF-pasteurized raw milk. The PEF treatment conditions evaluated were electric field strength of 30.76–53.84 kV/cm at 12, 24/21, and 30 pulses for skim milk (SM)/ whole milk (WM) at 20°C, 30°C, and 40°C using a monopolar pulse at a width of 2 μs. Minor variations in the physicochemical properties, due to changes in the protein and fat composition were observed after processing. The shelf life of SM and WM was assessed after processing at 46.15 kV/cm, with temperature (20–60°C) and 30 pulses; PEF-treated milk samples showed higher stability at 4°C, while samples stored at 21°C underwent faster spoilage. The growth of mesophilic bacteria was arrested in both samples by PEF treatment. PEF has been reported to be successful in inactivating pathogens in fluid milk. A challenge test and shelf-life study conducted on homogenizedmilkinoculatedwithSalmonelladublinandtreatedwith36.7 kV/cm and 40 pulses over a 25 min time period revealed its efficacy in inactivating the pathogen which was not detected in the PEF-treated milk even after storage at 7–9°C for 8 days (Dunn and Pearlman, 1987). PEF treatment as a novel nonthermal method has been reported for the processing of milk-based beverages. Dairy beverages including fruit juice-milk blends, milk drinks, and fermented dairy drinks have been subjected to PEF treatment. In a fruit juice and milk combination, the antioxidant capacities of the fruit constituents deliver the health benefits of milk. These products are commonly formulated with pectin as stabilizer, citric acid as acidifier, sugar, and a proportion of water. Nevertheless, commercialization of such products depends on both the technology applied for their preservation and their ingredients and formulation (Granato et al., 2010). Mixed beverages are usually stabilized by thermal processes that partially degrade their nutrient properties. Escherichia coli inactivation in an orange juice (50%) and milk (20%) mixed beverage reported a 3.83 log reduction of E. coli after PEF treatment at 15 kV/cm for 700 μs (Rivas et al., 2006). Study on salmonella spp. inactivation using PEF treatment was also conducted in orange juice (30%) milk (20%) beverage (Sampedro et al., 2011). The authors applied a Monte Carlo simulation coupled with a secondary

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predictive model based on the Weibull distribution function to predict the final load of Salmonella typhimurium cells in orange juice beverage as influenced by electric field intensity, pH, and pectin concentration. The models predicted a 5-log reduction for a PEF treatment based on 35 kV/cm, 60 and 40 μs at a pH of 4.5 and 3.5, respectively. Salvia-Trujillo et al. (2011) described a 5 log reduction of Listeria innocua in an orange (30%), mango (10%), and apple (10%) fruit juice beverage mixed with whole milk (FJ-WM) or skimmed milk (FJ-SM) subjected to high-intensity pulsed electric fields (HIPEF) treatment (35 kV/cm, bipolar 4 μs square wave pulses at 200 Hz). HIPEF and thermal processing ensured the microbial stability of the beverages after 56  days at 4°C without significant changes on pH, acidity, and soluble solid content values. HIPEF or thermally treated samples showed higher viscosity than the untreated ones, the increment being more pronounced in the beverages with WM. Electric fields inactivated Saccharomyces cerevisiae more readily than Lactobacilli inoculated into yoghurt. The shelf life of yoghurt inoculated with yeast and treated subjected to an electric field at 45°C was found to be increased by 10 days when stored at 4°C and treatment at 55°C resulted in one month extension of shelf life at 4°C (Dunn and Pearlman, 1987). Yoghurt, flavored milk, and yoghurt drinks when treated with PEF and heat, did not exhibit any change in sensory attributes of the products. The shelf life at 4°C of a yogurt-based beverage flavored with strawberry, grape, and blueberry and processed by a combined treatment of heat (60°C, 30 s) plus PEF (30 kV/cm, 32 μs) was reported 90 days with 2–4 log reductions in total viable counts and molds (Yeom et al., 2007). A detailed investigation on the role of PEF treatment as a potential modulator to control the growth of a probiotic bacterium (Lactobacillus acidophilus LA-K) was reported by Cueva and Aryana (2012). The treatment combinations studied included electric field strength (5, 15, 25 kV/cm), pulse widths (3, 6, 9 μs) for a duration of 10,000, 20,000, and 30,000 μs. It was observed that the growth rate of the target probiotic was significantly influenced by the strength of the electric field and the nature of pulse (bipolar) and pulse duration slowed the log-phase growth rate of the bacterium. The authors discussed the importance of successfully regulating the growth of culture bacteria in controlling the texture and flavor of fermented dairy foods such as yoghurt, suggesting a new avenue for the application of PEF technology. The potential of PEF as a friendly technology in relation to the more sensitive components of foods has also been discussed in the context of the effectiveness of PEF treatments on the inactivation of Cronobacter sakazakii in infant formula milk (Pina-Perez et al., 2007). Infant formula milk was inoculated with C. sakazakii and treated from 10 to 40 kV/cm and from 60 to 3895 μs. A maximum of 1.2 log reduction was achieved after 40 kV/cm, 360 μs. The authors concluded that there were good prospects for the use of PEF in hospitals

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to achieve safe reconstituted infant formula before storage at refrigerated temperatures. The efficacy of PEF treatment in inactivating spoilage and pathogenic microorganisms depends on operating parameters (electric field strength, pulse duration, shape and width, bipolar/monopolar pulses), type, and stage of growth of microorganism itself, and extrinsic product factors such as temperature, pH, ionic strength, etc. Currently, the application of this technology in dairy products has been restricted to inactivation of select microbes in milk and liquid products such as dairy beverages, but ample scope exists for further applications in dairy products once the effect of PEF on the physical and chemical constituents of milk is fully understood. Also with advancement in design and development of PEF systems, it is expected that economic and cost effective equipment would lead to a wider adoption of the technology on a commercial scale.

12.3  High-Pressure Processing High-pressure processing (HPP) is one of the emerging nonthermal food processing technology that has gained huge momentum as a novel technique to process food products with excellent retention of its “fresh” sensory attributes. HPP-treated products are reported to be safe, have better texture and extended shelf life (ESL), also have increased retention of nutrients in comparison to thermal-processed foods. In light of the above advantages, HPP has been regarded as one of the best innovations in food processing in 50 years. A close perusal of the timeline of this novel technology indicate that Royer (France) in 1895 used high pressure to kill bacteria experimentally and Hite (USA) in 1889, successfully used pressure (689 MPa) to process certain beverages and found that some bacteria could be inactivated (Liepa et  al., 2016). During early times, the technology was shunned to be economically unviable due to the high cost of HPP vessels and its poor capacity. Frequent breakdown during operations labeled the vessels to be unreliable with poor scale up for its commercial adoption. However, with improved design and enhanced capacities over the decades, HPP has increasingly being acknowledged as one of the most important unit operation in food processing and preservation. Commercially speaking, Japan was among the first countries to produce the high-pressure jams and fruit products in 1980. About 82 industrial HPP plants have been installed all over the world with volumes from 35 to 360 L with an annual production volume of more than 100,000 tons by the end of 2005 (REF). From milder pressures (300 MPa) for self-shucking oysters to poultry products, and fruit juice processed by HPP (up to 600 MPa), the application and market of HPP-treated foods has seen a significant

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upswing (Patterson et al., 2006). HPP has now evolved as a commercial process for over 100 different foods, including meat, jams, yoghurt, juices, seafood, fruit and vegetable, and ready-to-eat products (Balasubramaniam et al., 2004).

12.3.1 Principles Three fundamental operational principles have been proposed and widely accepted to explain the working of HPP, viz; Le-Chatelier’s principle, isostatic principle, and principle of microscopic ordering. Le-Chatelier’s principle: Any phenomenon in equilibrium chemical reaction, phase transition and/or change in molecular configuration that is accompanied by a decrease in volume can been enhanced by pressure (Naik et al., 2013). In other words, whenever a stress is applied to a system in equilibrium, the system will react so as to counteract the applied stress, reactions that result in reduced volume are enhanced under high pressure, such reactions may result in inactivation of microorganisms or enzymes. Isostatic principle: The transmittance of pressure is uniform and instantaneous, that is, independent of size and geometry of food (Naik et al., 2013). This principle implies that when a food product is compressed under HPP, it is subjected to uniform pressure in all directions and on depressurization, the food may regain its original shape. Hence HPP is also referred to as isostatic processing technique. Microscopic ordering: The principle of microscopic ordering says that at constant temperature, an increase in pressure increases the degrees of ordering of molecules of a given substance. Therefore, pressure and temperature exert antagonistic forces on molecular structure and chemical reactions (Naik et al., 2013).

12.3.2 Operation Basically in HPP, food is subjected to pressures as high as 6000 times the atmospheric pressure ranging from 300 to 700 MPa (Chawla et  al., 2011). In general, high-pressure processing is carried out in three steps viz., an initial period required for reaching the treatment pressure or come-up time, the time of processing at the desired pressure or holding time, and finally, a short-time necessary for releasing the pressure or release time. The process is commonly operated on a batch mode and applied to several liquid and semisolid prepacked foods and food ingredients. Typically, HPP system consists of four main parts, namely 1. a high-pressure vessel and its closure; 2. a pressure generating system; 3. a temperature control device; and 4. a material handling system

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12.3.2.1  Batch Process In batch operation, food is packed and loaded into the pressure vessel, followed by sealing and fastening of the ends of the vessel. The pressure-transmitting medium (usually potable water) is pumped into the vessel, pressure is generated within the vessel using specially designed pressure intensifiers, and the pressurized medium is allowed to remain inside in contact with the product for desirable time- pressure combination (holding). This is followed by reliving of the pressure (depressurization) by opening the pressure relief valve which allows the pressurized water to expand and return to atmospheric pressure. Batch processing has the advantage of isolation, thus the prevention of any risk of cross contamination and ensuring better hygiene. This mode is simpler to operate and usually requires little or no cleanup between batches in an operation shift.

12.3.2.2  Semicontinuous Process Semicontinuous systems consist of a free moving piston that acts as a separator between the food and the pressurizing medium. Typically, a low-pressure pump is used to initially pump the liquid food into the vessel. Once filled, the inlet port is closed and high-pressure process water is pumped behind the free piston to compress the liquid food. The piston generates the pressure on to the food for the desirable time-­pressure combination. After an appropriate process hold time, the system is decompressed by releasing the pressure. Specifically designed valves ensure that no intermixing of treated product and incoming untreated product occurs in the HPP unit. In this process the whole process, that is, product tank and discharge port, must be sterilized and the treated food is aseptically filled in pre-sterilized containers or packages.

12.3.2.3  Continuous Process As a reference to word continuous, on a commercial-scale liquid food is processed continuously via a plug flow hold tube or hold vessel. It basically comprises of semicontinuous systems operated using three pressure vessels in tandem (one loading, second compressing, and third discharging) to achieve a continuous throughput. The decompressed treated liquid is sent to a sterile hold tank for eventual aseptic filling.

12.3.3 Applications Significant progress in the engineering of large-scale high-pressure equipment has allowed this technology to be adapted to the needs of the food industry and this has coincided with an increased interest in high-pressure treatment of foodstuffs in recent years. Application of HPP on milk and milk beverages have been widely reported including

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its implementation and adoption in the dairy process industry. In fact, the first reports on HPP in food dealt with the processing of milk: Bert Hite in 1899 at West Virginia University Agricultural published the first detailed report of the use of high pressure as a method of milk preservation. He reported that milk “kept sweet for longer” after a pressure treatment of approximately 650 MPa for 10 min at room temperature. A significant advantage of HPP in milk processing is that simultaneous to inactivation of microorganisms and extension of the shelf life of the product, the process also homogenizes the milk. Microorganisms in lag phase are more sensitive to HP than those in stationary phase (Bello et  al., 2014). HPP processing of milk has also demonstrated a reduction in the size of the fat globule, denaturation of whey proteins and inactivation of some enzymes such as plasmin (Naik et al., 2013); most of the technologically important milk enzymes lose their activity at pressures above 300 MPa. Cell inactivation may also be increased by increasing the temperature (Juck et al., 2012). Temperature increase during HPP caused by adiabatic heating also must be taken into account. Conformational changes of milk constituents (primarily proteins and fat) have been reported on HPP and this has an effect on the physicochemical and technological properties of the treated milk (Chawla et al., 2011). Extensive disruption of casein micelles with a concurrent effect on milk turbidity and lightness has been observed at pressures above 250 MPa. Enhanced hydrolysis altered functionality of whey proteins when subjected to pressures greater than 400 MPa have resulted in attributes such as improved hardness, hydrophobicity, solubility, gelation, and emulsification. Pressures above 500 MPa at temperatures of 25oC and 50oC have been successfully employed to enhance the distribution of smaller fat globules in ewe’s milk (Gervilla et al., 2001) with no significant damage to the fat globule membrane thus arresting creaming off in the treated milk. The process also demonstrated no lipolysis, thus ensuring that no off flavors are produced due to HPP treatment of milk. It has been widely observed that Gram-positive microorganisms are more resistant than Gram-negative organisms to HPP. As a general guideline the latter are inactivated at around 300–400 MPa, while the former organisms need to processed at pressures greater than 500 MPa for similar durations and at identical temperatures to achieve the same results. The efficiency of HPP in inactivation of pathogenic and spoilage organisms in milk has been well documented and milk processed at 400–600 MPa is reported to have similar quality like that of pasteurized milk (Chawla et al., 2011). HPP is also reported to be beneficial in preserving bovine colostrum which is rich in bioactive components, such as immunoglobulin and lactoferrin that may provide health benefits to consumers. Attaining a commercially viable shelf-life product in this category

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has been a challenge, because of its relatively sensitivity to denaturing by conventional thermal preservation methods. Immunoglobulin in particular cannot withstand UHT or heat-sterilization processes, although they do survive thermal pasteurization well. Foster et  al. (2016) discussed the feasibility of employing HPP to preserve bovine colostrum by optimizing process conditions for maximizing bacterial inactivation while minimizing changes in its immunoglobulin content and viscosity of the product meant for calf feeding. There also exists a possibility of using HPP, a nonthermal food preservation technology, to produce a ready-to-drink colostrum beverage with a commercially useful shelf-life. Several reports have demonstrated the efficiency of HPP in ensuring the safety and quality of milk-based beverages. Pina-Perez et  al. (2012) evaluated the stability of milk-egg-cocoa mixture beverage treated by HPP (100, 200, 300 MPa) and stored (10°C, 15 days) and reported an inactivation of Bacillus cereus. Results indicated that beverage supplemented with cocoa powder had final B. cereus concentration level of 6 CFU/mL at 95% probability, being below the infectious dose (104–105 CFU/mL). A functional orange juice-milk blend processed using HPP at four different pressures (100, 200, 300, and 400 MPa), four treatment times (120, 300, 420, and 540 s) was evaluated for retention of its antioxidant compounds and quality attributes (Barba et al., 2012). Ascorbic acid retention in the orange juice-milk beverage was 91% higher in all cases after HPP as compared to conventional process. Total carotenoid content was significantly higher and color changes increased at higher pressure and treatment times, with the highest difference appearing at 400 MPa/540 s. A 5-log reduction of Lactobacillus plantarum CECT 220 was observed in the orange juice-milk beverage after HPP (200 MPa, 300 s). An exercise evaluating the effect of HPP and TT on plant bioactive compounds (tocopherols, carotenoids, and ascorbic acid) in 12 fruit juice-milk beverages and the role of the food matrix (WM [JW], skimmed milk [JS], and soy milk [JSy]) in modulating their bioaccessibility (%) was reported by Cilla et al. (2012). HPP (400 MPa/40°C/5 min) produced a significant decrease in carotenoid and ascorbic acid bioaccessibility in all three beverages and maintained the bioaccessibility of tocopherols in JW and JS. This implies that HPP combined with a milk matrix positively modulates the bioaccessibility of certain types of bioactive components in food. Blayo et al. (2016) reported a study on 10% dispersed whey protein isolate (WPI) where the pressure processing was evaluated using two pathways: (i) high hydrostatic pressure at 300 MPa and 25°C for 15 min and (ii) ultra-high-pressure homogenization (UHPH) at 300 MPa at an initial fluid temperature of 24°C. Short-time thermal treatment (STTT) at 75°C for 10 s, 43 s, or 110 s was studied for ­comparison.

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­ rocessing-induced effects investigated that UHPH followed by effiP cient cooling at the high-pressure valve outlet significantly reduced protein denaturation. However, an increase in protein susceptibility to tryptic attack in the high-pressure treated samples was observed. The study implies that whey drinks can be processed using HPP with cooling being an important step in the process flowchart. Tadapaneni et  al. (2012) investigated processing strategies and matrix effects on the antioxidant capacity (AC) and polyphenols (PP) content of three different fruit-based beverages formulations: (1) strawberry powder (Str)+dairy, D-Str; (2) Str+water, ND-Str; and (3) dairy+no Str, D-NStr. Beverages were subjected to high-­temperatureshort time (HTST) and HPP treatments and AC and PP were monitored periodically over 5 weeks of storage. Significant reductions in AC were observed in HTST-processed beverage compared to HPP-processed beverages (up to 600 MPa). PP content was also significantly reduced processed samples. The authors concluded that both the processing and the presence of dairy component in the fruit beverage had a negative effect on its antioxidant capacity. The resistance of Listeria monocytogenes, Salmonella spp. and E. coli 0157:H7 to HPP in an acidic whey protein beverage (pH 3.8) was evaluated by Simpson (2012). Whey samples were spiked with the culture at approximately 6–7 log10 CFU/mL and samples were subjected to pressurization treatments for 2, 4, 6, or 8 min at pressures ranging from 200 to 500 MPa. Among the pathogens inoculated, E. coli exhibited the greatest resistance to high pressure. The interactive effect of select bacteriocins (50 ppm nisin, 50 ppm nisin and 0.04% (w/v) potassium sorbate, 0.04% (w/v) potassium sorbate) and high pressure treatment (400 MPa for 4 min) on the survival of E. coli 0157:H7 was studied over 5 days of storage at 25°C. The antimicrobials were found to improve the efficacy of HPP in containing the growth of E. coli in the whey beverage. HPP offers microbial stability in acidified dairy systems, as spoilage microorganisms that can grow are inactivated by pressure (e.g., lactic acid bacteria, yeast, and mold) and microorganisms that are not inactivated by pressure cannot grow (e.g., bacterial spores). Also, HPP treatment results in physicochemical changes in the milk positively quality and sensory attributes of fermented dairy products. Thus, this technology is often discussed as an alternate treatment for products such as cultured milks and yoghurts with improved quality and ESL (Da Cruz et al., 2010). HPP resulted firmer yoghurt when yoghurt was prepared from lowfat milk exposed to 300 MPa pressure and 10 min of treatment time; firmness increased with increase in pressure. This behavior of coagulated products is linked to the fact that disruption of casein micelles resulting in a greater effective area for surface interaction. The HPP

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treatment also resulted in nondevelopment of in-pack acidification and significantly improved shelf life (Harte et al., 2003). Ancos-Begona et al. (2000) studied the effects of high pressure, that is, 100–400 MPa for 15 min at 20°C on the physicochemical, chemical, microbiological, and sensory characteristics of stirred low-fat yoghurt. No significant changes in pH and total organic acids were observed after pressuring the yoghurt. Pressures over 200 MPa prevented post-acidification of the yoghurt during storage, this finding pointed toward a scope for eliminating the use of addition of additives in yoghurt to prolong shelf life. Penna et  al. (2006) investigated the effect of using HPP (676 MPa for 5 min) and heat treatment (85°C for 30 min) alone on milk to be used for the production of probiotic yogurts with two different starter cultures and Bifidobacteria longum. The authors reported that the use of HPP led to compact yogurt gels with increasingly larger casein micelle clusters interspaced by void spaces, and exhibited a high degree of cross-linking. On the other hand, in yogurt produced with milk submitted only to heat treatment, the micelles were less interconnected and exhibited irregular shapes with large pores. HPP has also been credited with better survival and viability of starter culture and probiotics in comparison to other conventional preservation technologies, which makes the technology very compatible with fermented dairy products. De Oliveira et al. (2014) reported on the fermentation kinetics and the rheological behavior of HP-homogenized milk during fermentation and storage. Milk (2% v/v fat) was subjected to conventional homogenization (15/5 MPa, control treatment) and dynamic high pressure (DHP) at 50/5 MPa, 100/5 MPa, 150/5 MPa, and 180/5 MPa. The treated samples were inoculated with starter culture (Streptococcus thermophilus+L. acidophilus) and the product fermentation and gel rheology was monitored. The fermentation kinetics was not affected by treatment; the product rheology improved with pressure in terms of greater consistency (15%), lesser syneresis (31%); the gel rheology improved with storage up to 28  days indicating that DHP could be applied to manufacture more compact gel probiotics with similar fermentation to conventional products. The application of HHP to milk for yoghurt preparation as an alternative to the use of food additives, which could adversely affect the taste, flavor, aroma, and mouthfeel of yoghurt was also discussed by Sfakianakis and Tzia (2014).

12.4  Pulsed Light PL processing technique has been commercialized in recent years and there have been many reports on the wide spectrum application of this technology. PL processing is highly novel as it not only decontaminates the food or packaging but also maintains its texture and nutrients.

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The bactericidal effect of continuous UV light was discovered by Jagger in 1967, this eventually led to the evolution of a technique for decontamination and sterilization for various medical and dental instruments, devices, and packages (Barbosa-Canovas et  al., 1999). In comparison, the use of PL technology in the food industry for decontamination purposes was popularized after FDA approval in 1996. PL technology offers considerable advantages due to its higher penetration depth and emission power that is effective and rapid in microorganism inactivation (the delivered energy is multiplied manifold) and a lower heating effect (due to short pulse duration and cooling period between pulses). PL includes a wide wavelength range of 200– 1100 nm, which includes ultraviolet (UV): 200–400 nm, visible (VIS): 400–700 nm, and near-infrared region (IR): 700–1100 nm (Bhavya and Umesh, 2017). Apart from decontamination PL technology has also been applied for reducing the allergen potent of some naturally occurring foods (Abida et al., 2014). This technique is rapidly gaining acceptance as a rapid and effective low thermal, low energy purification and sterilization technique using very high power and short duration light pulses emitted by inert gas flash lamps. However, the application of PL is limited to treatments of very transparent foods, surface treatments for foods, packaging, surfaces, and equipment; it cannot be used for solid food (Yasothai and Giriprasad, 2015).

12.4.1 Principles The lethality of PL is often attributed to the wide spectrum of electromagnetic radiation involved (including a large UV content), short pulse duration emanated at high amplitude power and the feasibility of the flash lamps to emit radiations at regulated frequency and pulse width. PL uses light energy in concentrated form (0.01– 50 J/cm2) and exposes the substrate to intense short bursts of light (ns to ms) resulting in an amplification of power with a minimum of energy consumption. Although the light spectrum generated by the PL units has a similar composition to sunlight, because the intensity involved, it is estimated to be roughly 20,000–90,000 times stronger than sunlight on earth’s surface. The understanding of the germicidal effects of PL processing is presently very complex and mainly credited to a combination of several phenomena including short-term, thin-layer temperature effects, that is, photothermal effects (the treated surfaces momentarily reaching up to 7000°C), photochemical effects (formation of free radicals), and DNA damage to microorganisms (Cheigh et  al., 2012; Ramos-Villarroel et  al., 2012; Nicorescu et al., 2013). PL technology is often described in terms of its fluence rate, fluence dose, peak power, and pulse repetition rate (Abida et al., 2014).

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Keener and Krishnamurthy (2014) explain inactivation principle as follows: 12.4.1.1. Photochemical damage: The UV light portion of the PL damages the DNA of bacteria by forming thymine dimers. Upon dimer formation, bacterial DNA cannot be unzipped for replication, and thus bacteria cannot reproduce (Krishnamurthy et al., 2007). 12.4.1.2. Photothermal damage: Localized heating of bacteria is induced by PL due to the difference in the heating/cooling rate and absorption characteristics of the bacteria and the surrounding matrix. Thus, the bacterial cell acts as a local vaporization center and may lead to membrane destruction and cell wall rupture. Thermal stress leads to rupture of microbial cells especially at higher flux densities (>0.5 J/cm2). 12.4.1.3. Photophysical damage: PL is also expected to induce some physical disruption on microbial cellular structures due to the intermittent, high-intensity pulses (HIPs). Researchers have observed cell wall damage, membrane rupture, cytoplasm damage, etc. in bacterial cells exposed to PL, even when the temperature increase was negligible, suggesting that photophysical effects can play a vital role in microbial inactivation.

12.4.2 Application A pilot study conducted by Smith et al. (2002) investigated the inactivation of mesophilic aerobic bacteria in bulk tank milk with PL treatment by exposing 1 ml of milk to pulsed energy at 25 J/cm2. Results showed a complete elimination of the mesophilic bacteria in bulk tank milk as no growth occurred in subcultured samples even after incubation for 21 days proving that the bacterial content of raw milk can be adequately regulated using PL treatment. The technology has scope to be adopted for on-farm (similar to thermization) application to reduce the growth of spoilage bacteria. This could eliminate the need for high heat treatments such as UHT processing that are often associated with problems like gelation and bitter and rancid flavors in ESL milk. The authors also demonstrated the inactivation of seven strains of pathogens (E. coli, Salmonella choleraesuis, Yersinia enterocolitica, Staphylococcus aureus, Aeromonas hydrophila, Serratia marcescens) by similar PL treatment. The inactivation efficiency of PL treatment for S. aureus in milk in a continuous mode was investigated by Krishnamurthy et al. (2007). The effects of processing parameters such as distance of milk sample from the PL source (5–11 cm), number of passes (1–3 passes), and low rate of milk (20–40 mL/min) for PL treatment using three pulses per

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second and an exposed energy at 1.27 J/cm on milk samples per pulse were studied. The results indicated log reduction of 0.55–7.26 log and complete inactivation of S. aureus when treated at 8 cm sample distance with a single pass and 20 mL/min low rate, and at 11 cm sample distance with two passes and 20 mL/min low rate combinations. The inactivation of microbes using PL is enhanced at higher pulse numbers and higher intensity pulses (Ramos-Villarroel et  al., 2014). Miller et al. (2012) assessed the inactivation of E. coli in milk by exposing 1 mL of milk inoculated with E. coli was exposed of 2.14–14.9 J/cm2. The study also aimed at evaluating the effects of total solids and fat content of milk on germicidal effectiveness (in terms of transmission) of the technology. PL exposure in contaminated raw milks resulted in reduction levels of 3.4 log of the E. coli population in the skimmed milk and a greater than 2.5 log reduction of the bacterial population in both skimmed milk and WM after treatment with PL at 14.9 J/cm2 under turbulent conditions. The study indicated that PL treatment is effective for the decontamination of E. coli in milk in turbulent conditions. A limited effectiveness of the technology for inactivating microbes was reported in concentrated milk, primarily due to the poorer transmission properties (absorption of PL) and shielding effect of milk solids limiting the exposure to the bacteria to the lethal effects of incident PL. Pioneering work of Choi et  al. (2010) demonstrated commercial feasibility of intense PL treatment of infant formula, as an alternative to conventional pasteurization, using 10–25 kV pulses on 2 mm on thick infant foods, including an infant beverage, an infant meal, and an infant milk powder containing 105CFU/g of L. monocytogenes. About 4–5 log reductions of L. monocytogenes were achieved for 5000, 600, 300, and 100 μs at 10, 15, 20, and 25 kV of voltage pulse, respectively. The results also demonstrated that complete killing of L. monocytogenes on agar plates was possible using PL treatment for 100 μs at 25 kV of voltage pulse. Lower viscosity of the infant beverage promoted greater cell inactivation using PL. Similarly, a 5 log reduction of Enterobactor sakazakiiin an infant beverage, infant meal, and powdered infant milk was achieved with PL treatment at 10 and 15 kV, after 4.6 and 1.8 ms, respectively. The authors were also successful in achieving an exponential inactivation of bacteria on a temporal scale using PL at 15 kV (Choi et al., 2009). The results highlighted a potential for commercial application of PL treatment for the pasteurization of beverages of low viscosities in the dairy industry. Innocente et al. (2014) studied the effect of PL (fluence ranging between 0.26 and 26.25 J/cm2) on inactivation of microbial load and the enzyme alkaline phosphatase (ALP) in raw WM and observed a 3.2log reduction of microbial load with a 94% inactivation of the enzyme; a simultaneous heating of the milk (temperature rising to 55°C) was also reported. Palgan et al. (2011) discussed the poorer effectiveness

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of PL in inactivating E. coli and L. innocua while preserving product quality in milk when compared with more transparent fruit juices such as apple juice. Fernandez et  al. (2012) evaluated the impact of PL technology on the surface properties of whey protein by treating β-lactoglobulin solutions (protein concentration 0.5–10 mg/mL) at the dose level of total fluence of 4 J/cm2. PL treatment caused partial denaturation of the whey proteins, suggesting that PL-treated whey proteins would be employed as a functional ingredient to improve foaming in the food industry. Orlowska et al. (2013) compared the performance of three different sources of HIP UV lamps (HIP-1: 31 J/pulse, 8 Hz; HIP-2: 344 J/pulse, 0.75 Hz; HIP-3: 644 J/pulse, 0.5 Hz) at a fluence of 5 mJ/cm2 against two conventional mercury lamps (fluence of 10 mJ/cm2) during the treatment of vitamin C enriched milk. The study revealed no significant difference in pH and color parameters of treated and untreated samples; however, a possible photolysis of light-sensitive riboflavin and the influence of its breakdown products (lumiflavin and lumichrome) in triggering oxidative changes in milk have been discussed. Siddique et  al. (2016) investigated the effects of PL processing at different fluences (from 4 to 16 J/cm2) on the structure and functional properties of WPI solution. The experimental data demonstrated that PL treatments increased the concentration of total and free sulfhydryl groups and protein carbonyls. Small but significant changes in the secondary structure of PL-treated WPI solution were also observed. The partial unfolding makes improve some functional properties such as solubility and foaming ability. These increased functional properties could be useful in developing whey-based beverages.

12.5  Ultrasonic Processing 12.5.1 Introduction Ultrasounds are high-intensity mechanical vibrations generated by sound waves that have the potential to cause cavitation and acoustic streaming that leads numerous changes in physicochemical as well as functional characteristics of food material (Ercan and Soysal, 2013). In recent times, ultrasound is emerging as a one of the fast, versatile, and nonthermal preservation technology which is being employed for foods processing. Ultrasounds have found wide range of applications in food processing industry including nondestructive testing of material, drying, crystallization, filtration, extraction, emulsifying, cleaning, and as preservation technique (via inactivation of microbes and enzymes) (Zisu et  al., 2013). The technology has been credited with numerous advantages such as reduction in the processing time, saving

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of energy, improving productivity and selectivity, reducing physical and chemical hazards, and improving the shelf life and quality of food products (Chemat et al., 2011).

12.5.2 Principle Ultrasound refers to sound waves and associated mechanical vibrations, which propagate through solids, liquids, or gases with a frequency greater than the audible frequency of 20 kHz. The ultrasound equipment is normally operated at frequencies of 20 kHz to 10 MHz (Lopez-Malo et  al., 2005). Propagation of these sound waves in liquid media generates alternating compression and expansion cycles. During the expansion cycle, high-intensity ultrasonic waves create small bubbles, which progressively coalesce. On attaining a threshold size and volume, the bubbles suffer a violent collapse due to its inability to absorb further energy. This cycle of bubble formation, expansion, and the implosion is technically referred to as cavitation. During the implosion, vicinity of the collapsing bubbles experience very high temperatures (approximately 5000 K) and pressures (estimated at 50000 kPa) that could shatter and break entities resulting in particle dispersion and cell disruption and giving a localized sterilization effect (Rokhina et al., 2009). The formation, growth, and collapse of bubbles during a cavitation are illustrated in Fig. 12.3.

12.5.3  Ultrasound Generation System Ultrasonic systems consist of a generator, transducer, and the application system. A generator produces electrical or mechanical energy and transducer converts the AC to ultrasound. Three types of

Fig. 12.3  Cavitation phenomenon (A) bubbles formation by sound waves; (B) bubbles growth to the maximum size during expansion cycle; and (C) bubbles collapse, and particle dispersion and cell disruption occurrence (Abdullah and Chin, 2014).

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transducers have been reported, namely fluid driven, magnetostrictive, and piezoelectric transducers (Mulet et al., 2003).

12.5.3.1  Methods of Ultrasound Ultrasound, in combination with other preservation methods (viz. pressure and/or temperature) for improving its inactivation efficiency, is finding increasing use in food process industry in general and beverage industry in particular. Accordingly, the process is classified as follow: 12.5.3.1.1. Ultrasonication: US is the application of ultrasound alone at low temperature, the process is usually recommended for products with heat-sensitive components. However, for effective inactivation of enzymes and/or microorganisms the process requires longer treatment time and therefore higher energy requirement (Zheng and Sun, 2006). 12.5.3.1.2. Thermosonication: TS refers to the combined effect of ultrasound and moderate heat. This technique has been reported to depict similar inactivation levels as high temperature treatment (without ultrasound), with a greater effect on inactivation of microorganisms than heat alone (Villamiel et al., 1999). 12.5.3.1.3. Manosonication: MS is a combined effect of ultrasound and pressure. MS provides to inactivate enzymes and/or microorganisms by combining ultrasound with moderate pressures (100–300 kPa) at low temperatures. Its inactivation efficiency is higher than ultrasound alone at the same temperature (Ercan and Soysal, 2013). 12.5.3.1.4. Manothermosonication: MTS is a combined effect of heat, ultrasound, and pressure. The applied temperature and pressure maximizes the cavitation or bubble implosion in the media which in turn enhances the level of inactivation. The method is reported to be very effective in inactivating thermoresistant enzymes, such as lipoxygenase, peroxidase and polyphenoloxidase, and heat-labile lipases and proteases from Pseudomonas (Chemat et al., 2011).

12.5.4 Application Ultrasound is considered as one of the potential nonthermal processing techniques in dairy and food industry that has an advantage of preserving food without the adverse side effects associated with conventional heat treatments (Jambrak et al., 2016). The main objective of ultrasound in dairy beverages include inactivation of microorganisms and enzymes, improving structural and functional properties of dairy ingredients, and as an alternative processing method (pasteurization),

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while retaining the original characteristics of beverages. In recent times ultrasound has also emerged as a viable option for pasteurization and pretreatment of milk prior to product manufacturing. Villamiel and de Jong (2000) investigated the effect of high-­intensity ultrasound on milk constituents such as ALP, γ-glutamyltranspeptidase, lactoperoxidase, whey proteins (α-lactalbumin and β-lactoglobulin), casein, and milk fat and compared the results with those obtained using a conventional heat treatment. It was found that ultrasound treatment alone had no any effect on the enzymes; while a synergistic effect of ultrasound and temperature was observed at temperature 61°C, 70°C, and 75.5°C for the inactivation of ALP, γ-­glutamyltranspeptidase, and lactoperoxidase, respectively. Conformational changes in casein were not detected but considerable denaturation of α-lactalbumin and β-lactoglobulin were recorded due to this synergistic effect. The effect of ultrasound (20 kHz) on milk fat globule showed a considerable ­reduction (up to 81.5%) in the size of the fat globule at ambient temperature and a better particle distribution was observed when ultrasound was combined with heat at 70°C and 75.5°C. Muller (1992) suggested the application of ultrasound for milk homogenization; the homogenization effect of ultrasound is attributed mainly to the formation of eddy currents in the fluid when it is sonicated. Riener et al. (2009) combined ultrasound with heat treatment (TS) for milk and achieved a similar effect on the milk fat globular membrane as obtained with ultrasound treatment without heat, leading to a reduction in size and changes in the membrane allowing interaction with casein micelles. TS treatment of milk leads to an average milk fat globular diameter of 0.6 μm and membrane richer in casein molecules than the native membrane. Continuous TS of pasteurized homogenized milk (1.5% fat) at 24 kHz, 400 W, and 45°C from 2.5 to 20 min resulted in an undesirable rubbery aroma; the intensity of rubbery aroma reduced when sonication power was decreased from 400 to 100 W. Wu et  al. (2000) investigated effects of ultrasound on milk homogenization and yoghurt fermentation. Ultrasound exhibited good homogenization effects at high amplitude levels (20 kHz, 50–500 W) compared with conventional homogenization while low power levels did not have efficient homogenization effects. Adequate exposure time (1–10 min) at required power of ultrasounds resulted in the formation of extremely small fat globules. Ultrasound treatment of milk prior to its inoculation led to enhanced water holding capacity and a marked decrease in syneresis. Ultrasound treatment post inoculation with yoghurt cultures decreased the total fermentation time by 0.5 h. Yoghurt produced from milk treated by high-intensity ultrasound showed improved physical properties and better texture characteristics (firmness and cohesiveness).

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Vercet et al. (2002) combined TS of milk (40°C, 20 kHz for 12 s) for yoghurt manufacturing with moderate pressure (2 kg/cm2) and observed that the treatment improved the texture of the fermented product by increasing the apparent viscosity, yield stress, and viscoelastic properties of yoghurt. This was attributed to the denaturation of whey proteins during the ultrasound treatment of milk and its association with casein micelles and consequent role as a bridging material between casein micelles resulting in formation of bonds in the yogurt matrix yielding a stronger coagulum. A similar interaction between denatured whey proteins and modified (reduced size) casein micelles were reported by Nguyen and Anema (2010) who investigated the effect of US on properties of SM used in the formation of acid gels and found that ultrasound treatment of SM for moderate times without temperature control could be used to produce acid gels with markedly increased final elastic modulus values (G′) and reduced gelation times. These effects were very similar to those achieved by conventional heating, and the final G′ values and gelation times achieved were similar to those processed under optimal ultrasound conditions. Ultrasound has been successfully applied to the milk for microbial inactivation but with a low lethality at low and ambient temperatures. Therefore ultrasound treatment is generally combined with heat and pressure for increasing its lethality effect, the inactivation efficiency varying greatly depending on the bacterial species and growth medium. The sensitivity of Gram-negative and rod-shaped microbial cells is greater than Gram-positive and coccal cells and expectantly bacterial spores are far more resistant to sonication than vegetative cells (Drakopoulou et al., 2009). Cameron et al. (2009) investigated the effect of ultrasound on microbes present in milk and reported that with US treatment the viable cell counts of E. coli and Pseudomonas fluorescens were reduced by 100% after 10.0 and 6.0 min, respectively and L. monocytogenes was reduced by 99% after 10.0 min, indicating that high-power ultrasound has a good potential in fluid milk as an alternative to the conventional pasteurization for inactivating microorganisms. However, the effect of ultrasound for inactivation of ALP or lactoperoxidase enzymes (indicators of pasteurization efficiency) is not yet elucidated. This necessitates a need for identifying a quick and efficient method to indicate the adequacy of US treatment in ensuring a microbiologically safe product, if US is to be considered as an alternative to thermal pasteurization. Nobel et  al. (2016) studied the effect of ultrasound treatment (45 kHz for 5 min) on the fermentation of SM for the manufacture of stirred yogurt; sonication of milk was reported to increase the subjective and objective texture (visual graininess) of stirred yogurt. Among the different pH ranges tested, a pH of 5.1–5.4 was identified as critical

Chapter 12  Nonthermal Processing of Dairy Beverages   419

due to an increase to the number and size of large microgel particles as well as the average particle size of the small microgel particles. Leong et  al. (2014) discussed sonication as a means to enhance fat separation in milk; a process that could be employed upstream to manufacturing of low-fat milk beverages. Fat separation from WM was achieved through US (1–2 MHz) in a batch system. The effect of various design parameters such as power input level, process time, specific energy, and transducer-reflector distance on efficiency of separation were tested. It was found that a higher energy density was key to increasing the rate of fat separation and could be achieved by reducing the vessel geometry or using dual transducers. The fat concentration of 20% w/v was achieved in the creamed top layer after applying a minimum specific energy of 200 kJ/kg. In addition, the fat separation was enhanced by reducing the transducer reflector distance in the vessel, or by increasing the process time, resulting in skimmed milk with a fat concentration as low as 1.7% (w/v) using raw milk after process time of 20 min. Lactose-free fermented milk is produced either by fermentation of lactose-hydrolyzed milk or by the simultaneous addition of β-galactosidase and lactic acid bacteria. These bacteria produce β-galactosidase which hydrolyzes the lactose in fermented milk (Wang and Sakakibara, 1997). Ultrasound has demonstrated a capability of enhancing the reaction activity of cells in lactose hydrolyzed fermented milk; ultrasound processing of lactose-free milk reported a lactose hydrolysis of around 55%; while for conventional methods it was around 36% (Wang et al., 1996). In general, hydrolysis of lactose by ultrasound is enhanced up to 20% compared to conventional methods (Villamiel et al., 1999), indicating a scope for its application in processing functional dairy beverages.

12.6  Ozone Treatment 12.6.1 Introduction Ozone treatment is emerging as nonthermal food preservation technique with potential application in the beverage industry due to the key changes it brings about in microbial, quality, and nutritional parameters of food. Ozone as a powerful broad-spectrum antimicrobial agent that is mainly used for surface decontamination of fruits and vegetables, drinking water disinfection, wastewater treatment and is active against bacteria, fungi, viruses, protozoa, and their spores (Karaca and Velioglu, 2007). Ozone is mainly applied to solid foods either in the form of gaseous ozone or ozonated water. However, with the FDA approval of ozone as a direct additive to food, the potential of ozonation in beverage applications has begun to be exploited.

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In the last decade, many beverage industries in the United States have started using ozone treatment to meet the FDA mandatory guideline of a5 log reduction of the most resistant target pathogens in their finished products.

12.6.2 Principles The primary mechanisms for the germicidal effect of ozonation is yet to be fully understood, but it is generally accepted that ozone has capability to interact with cellular constituents including proteins, unsaturated lipids and respiratory enzymes in cell membranes, nucleic acids in the cytoplasm, and proteins and peptidoglycan in spore coats and virus capsids (Patil and Bourke, 2012). Hence, inactivation of microbes by ozonation is often described as a complex process. There is also ambiguity on the pathway of inactivation of microbes with some authors considering molecular ozone as the main inactivator, while others describing the antimicrobial activity during ozonation due to its breakdown or decomposition by-products including radicals such as OH, O2–, and HO3 (Hunt and Marinas, 1997).

12.6.3 Equipment for Ozone Treatment Ozone is generated by the exposure of air or a gas mixture containing oxygen to an energy source such as a high-energy electrical field (corona discharge method), UV radiation (phytochemical method), or conversion of oxygen molecules (O2) to ozone (O3) (chemical method). The ozone treatment system consists of following components; the gas (air or pure oxygen), an ozone generator, an electric power source, a contactor (if ozone is in the aqueous phase), a reactor, a surplus gas elimination unit, and an ozone analyzer. Ozone in its aqueous and/or gaseous phases has been employed in the food processing industry.

12.6.4 Application Ozone has significant advantages over conventional antimicrobial agents due to its relatively inert influence on the sensory attributes of the product and hence is a viable antimicrobial agent with great potential in the beverage industry. Introduction of ozone into the product is usually in its gaseous or aqueous state in a stirred-tank or bubble column reactor (Miller et al., 2013). Even though reports on its applications in milk and dairy beverages is scarce, ample evidence of its successful application in allied food sectors exist, indicating a great scope for its cost-effective adoption for preservation of milk and milkbased beverages with minimal damage to its nutritional and sensory quality.

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Sheelamary and Muthukumar (2011) investigated the effect of ozonation on inactivation of L. monocytogenes in raw milk and various branded milk samples at a controlled dozing of 0.2 g/h of ozone. Ozonation for 15 min was successful in completely eliminating L. monocytogenes from both raw and branded milk samples. The samples were analyzed for protein, carbohydrate, and calcium content and a marginal effect due to ozonation was reported. Improvement of the microbial quality of raw milk by ozone treatment was also attempted by Cavalcante et al. (2013) who treated the raw milk samples with ozone gas at 1.5 mg/L for 5, 10, and 15 min. Enterobactereaceae, total mesophilic aerobic (TMA), psychrotrophic, molds, and yeast and Staphylococcus spp. were enumerated to study the efficacy of ozone treatment. Milk samples without ozone treatment reported counts of Enterobactereaceae, mesophilic aerobic, psychrotrophic, molds, and yeast and Staphylococcus as 2.39, 4.18, 3.01, 2.70, 2.16 log CFU/mL, respectively. The ozonation for 15 min achieved a significant reduction of 0.96, 0.60, 0.13, 0.48, and 1.02 log cycles for Enterobacteriaceae, mesophilic aerobic, psychrotrophic, molds and yeast, and Staphylococcus, respectively. Thus, ozone gas bubbling could be adopted as milk preprocess for improving the microbial quality of raw milk.

12.7 Conclusion Nonthermal processing offers promising alternatives to TT for processing of milk and dairy beverages with enhanced quality, safety, and shelf life. HPP and PEF treatments have been extensively studied and the engineering aspects of these technologies have progressed toward its adoption on a commercial scale in dairy processing. PL, sonication, and ozonation may require further understanding and elucidation of its effects on milk constituents and its interactions as well as refinement in its equipment before its adoption by the dairy industry. Nevertheless, they offer ample scope as technologies for improving the microbial quality of raw milk and dairy beverages with minimal impact on its nutritional and sensory attributes and also as a preprocessing unit operation to manufacture dairy products with improved quality attributes including texture and flavor.

References Abdullah, N., Chin, N.L., 2014. Application of thermosonication treatment in processing and production of high quality and safe-to-drink fruit juices. Agri. and Agril. Sci. Procedia 2, 320–327. Abida, J., Rayees, B., Masoodi, F.A., 2014. Pulsed light technology: a novel method for food preservation. Int. Food Res. J. 21 (3), 839–848.

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Ancos-Begona, D., Cano, M.P., Gomez, R., 2000. Characteristics of stirred low fat yogurt as affected by high pressure. Int. Dairy J. 10 (1), 105–111. Balasubramaniam, V.M., Ting, E.Y., Stewart, C.M., Robbins, J.A., 2004. Recommended laboratory practices for conducting high-pressure microbial inactivation experiments. Innovative Food Sci. Emerg. Technol. 5 (3), 299–306. Barba, F.J., Cortes, C., Esteve, M.J., Frigola, A., 2012. Study of antioxidant capacity and quality parameters in an orange juice–milk beverage after high-pressure processing treatment. Food Bioprocess Technol. 5 (6), 2222–2232. Barbosa-Canovas, G.V., Gongora-Nieto, M.M., Pothakamury, U.R., Swanson, B.G., 1999. Preservation of Foods With Pulsed Electric Fields. Academic Press, San Diego. Bello, E.F.T., Martinez, G.G., Ceberio, B.F.K., Rodrigo, D., Lopez, A.M., 2014. High pressure treatment in foods. Foods 3 (3), 476–490. Bermudez-Aguirre, D., Fernandez, S., Esquivel, H., Dunne, P.C., Barbosa-Canovas, G.V., 2011. Milk processed by pulsed electric fields: evaluation of microbial quality, physicochemical characteristics, and selected nutrients at different storage conditions. J. Food Sci. 76 (5), 289–299. Bhavya, M.L., Umesh, H.H., 2017. Pulsed light processing of foods for microbial safety. Food Quality Safety 1 (3), 187–202. Blayo, C., Vidcoq, O., Lazennec, F., Dumay, E., 2016. Effects of high pressure processing (hydrostatic high pressure and ultra-high pressure homogenisation) on whey protein native state and susceptibility to tryptic hydrolysis at atmospheric pressure. Food Res. Int. 79, 40–53. Cameron, M., McMaster, L.D., Britz, T.J., 2009. Impact of ultrasound on dairy spoilage microbes and milk components. Dairy Sci. Technol. (1), 83–98. Cavalcante, M.A., Leite, J., Unior, B.R.C., Tribst, A.A.L., Cristianini, M., 2013. Improvement of the raw milk microbiological quality by ozone treatment. Int. Food Res. J. 20, 2017–2021. Chawla, R., Patil, G.R., Singh, A.K., 2011. High hydrostatic pressure technology in dairy processing: a review. J. Food Sci. Technol. 48 (3), 260–268. Cheigh, C.I., Park, M.H., Chung, M.S., Shin, J.K., Park, Y.S., 2012. Comparison of intense pulsed light-and ultraviolet-induced cell damage in Listeria monocytogenes and Escherichia coli O157: H7. Food Control 25 (2), 654–659. Chemat, F., Huma, Z., Khan, M.K., 2011. Applications of ultrasound in food technology: processing, preservation and extraction. Ultrason. Sonochem. 18, 813–835. Choi, M.S., Cheigh, C.I., Jeong, E.A., Shin, J.K., Park, J.Y., Song, K.B., Chung, M.S., 2009. Inactivation of Enterobactersakazakii inoculated on formulated infant foods by intense pulsed light treatment. Food Sci. Biotechnol. 18 (6), 1537–1540. Choi, M.S., Cheigh, C.I., Jeong, E.A., Shin, J.K., Chung, M.S., 2010. Nonthermal sterilization of Listeria monocytogenes in infant foods by intense pulsed-light treatment. J. Food Eng. 97 (4), 504–509. Cilla, A., Alegria, A., de Ancos, B., Sanchez-Moreno, C., Cano, M.P., Plaza, L., Barbera, R., 2012. Bioaccessibility of tocopherols, carotenoids, and ascorbic acid from milk-and soy-based fruit beverages: influence of food matrix and processing. J. Agric. Food Chem. 60 (29), 7282–7290. Cueva, O., Aryana, K.J., 2012. Influence of certain pulsed electric field conditions on the growth of Lactobacillus acidophilus LA-K. J. Microbial Biochem. Technol. 4, 137–140. Da Cruz, A.G., Faria, J.D.A.F., Saad, S.M.I., Bolini, H.M.A., Sant, A.S., Cristianini, M., 2010. High pressure processing and pulsed electric fields: potential use in probiotic dairy foods processing. Trends Food Sci. Technol. 21 (10), 483–493. De Oliveira, M.M., Augusto, P.E.D., da Cruz, A.G., Cristianini, M., 2014. Effect of dynamic high pressure on milk fermentation kinetics and rheological properties of probiotic fermented milk. Innovative Food Sci. Emerg. Technol. 26, 67–75. Drakopoulou, S., Terzakis, S., Fountoulakis, M.S., Mantzavinos, D., Manios, T., 2009. Ultrasound-induced inactivation of gram-negative and gram-positive bacteria in secondary treated municipal wastewater. Ultrason. Biochem. 16 (5), 629–634.

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Dunn, J.E., Pearlman, J.S., 1987. Methods and Apparatus for Extending the Shelf-Life of Fluid Food Products. U.S. Patent Washington, DC. No. 4,695,472. Ercan, S.S., Soysal, C., 2013. Use of ultrasound in food preservation. Nat. Sci. 5, 5. Fernandez, E., Artiguez, M.L., de Maraon, I.M., Villate, M., Blanco, F.J., Arboleya, J.C., 2012. Effect of pulsed-light processing on the surface and foaming properties of β-lactoglobulin. Food Hydrocoll. 27 (1), 154–160. Fetterman, J.C., 1928. The electrical conductivity method of processing milk. Agric. Eng. 9 (4), 107–108. Foster, D.M., Poulsen, K.P., Sylvester, H.J., Jacob, M.E., Casulli, K.E., Farkas, B.E., 2016. Effect of high-pressure processing of bovine colostrum on immunoglobulin G concentration, pathogens, viscosity, and transfer of passive immunity to calves. J. Dairy Sci. 99 (11), 8575–8588. Gamli, F., 2014. A review of application of pulsed electric field in the production of liquid/semi-liquid food materials. Adv. Res. Agri. Vet. Sci. 1 (2), 54–61. Gervilla, R., Ferragut, V., Guamis, B., 2001. High hydrostatic pressure effects on color and milk-fat globule of ewe’s milk. J. Food Sci. 66 (6), 880–885. Granato, D., Branco, G.F., Cruz, A.G., Faria, J.D.A.F., Shah, N.P., 2010. Probiotic dairy products as functional foods. Compr. Rev. Food Sci. Food Saf. 9 (5), 455–470. Harte, F., Luedecke, L., Swanson, B., Barbosa-Canovas, G.V., 2003. Low-fat set yogurt made from milk subjected to combinations of high hydrostatic pressure and thermal processing. J. Dairy Sci. 86 (4), 1074–1082. Hunt, N.K., Marinas, B.J., 1997. Kinetics of Escherichia coli inactivation with ozone. Water Res. 31, 1355–1362. Innocente, N., Segat, A., Manzocco, L., Marino, M., Maifreni, M., Bortolomeoli, I., Nicoli, M.C., 2014. Effect of pulsed light on total microbial count and alkaline phosphatase activity of raw milk. Int. Dairy J. 39 (1), 108–112. Jambrak, A.R., Vukusic, T., Herceg, Z., 2016. Application of ultrasonics in food preservation and processing. In: Bhattacharya, S. (Ed.), Conventional and Advanced Food Processing Technologies. John Wiley and Sons Ltd., UK, pp. 515–535. Juan, L.Y., Ngadi, M., Raghavan, V., 2012. Proteolysis of cheese slurry made from pulsed electric field-treated milk. Food Bioprocess Technol. 5 (1), 47–54. Juck, G., Neetoo, H., Beswick, E., Chen, H., 2012. Influence of prior growth conditions, pressure treatment parameters, and recovery conditions on the inactivation and recovery of Listeria monocytogenes, Escherichia coli, and Salmonella Typhimurium in turkey meat. Int. J. Food Microbiol. 153 (1), 203–211. Karaca, H., Velioglu, Y.S., 2007. Ozone applications in fruit and vegetable processing. Food Rev. Int. 23, 91–106. Keener, L., Krishnamurthy, K., 2014. Shedding light on food safety: applications of pulsed light processing. Food Safety Mag. 20 (3), 28–33. Krishnamurthy, K., Demirci, A., Irudayaraj, J.M., 2007. Inactivation of Staphylococcus aureus in milk using flow-through Pulsed ultraviolet light treatment System. J. Food Sci. 72, 233–239. Kumar, Y., Patel, K.K., Kumar, V., 2015. Pulsed electric field processing in food technology. Int. J. Technol. Eng. Stud. 1 (2), 6–17. Leong, T., Johansson, L., Juliano, P., Mawson, R., McArthur, S., Manasseh, R., 2014. Design parameters for the separation of fat from natural whole milk in an ultrasonic litre-scale vessel. Ultrason. Sonochem. 21, 1289–1298. Liepa, M., Zagorska, J., Galoburda, R., 2016. High-pressure processing as novel technology in dairy industry: a review. Food Sci. 1, 76–83. Research for Rural Development. Loeffler, M.J., 2006. Chapter  2: Generation and application of high intensity pulsed electric fields. In: Raso, J., Heinz, V. (Eds.), Pulsed Electric Fields Technology for the Food Industry Fundamentals and Applications. Springer, pp. 27–72. Lopez-Malo, A., Palou, E., Jimenez-Fernandez, M., Alzamora, S.M., Guerrero, S., 2005. Multifactorial fungal inactivation combining thermosonication and antimicrobials. J. Food Eng. 67, 87–93.

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Miller, B.M., Sauer, A., Moraru, C.I., 2012. Inactivation of Escherichia coli in milk and concentrated milk using pulsed-light treatment. J. Dairy Sci. 95, 5597–5603. Miller, F.A., Silva, L.M., Brandao, T.R.S., 2013. A Review on ozone-based treatments for fruit and vegetables preservation. Food Eng. Rev. 5 (2), 77–106. Mohamed, M.E.A., Eissa, A.H.A., 2012. Chapter  11: Pulsed electric fields for food processing technology. In: Eissa, A.H.A. (Ed.), Structure and Function of Food Engineering. INFOTECH, pp. 275–306. Mulet, A., Carcel, J., Benedito, C., Rossello, C., Simal, S., 2003. Ultrasonic mass transfer enhancement in food processing. In: Welti-Chanes, J., Vélez-Ruiz, F., Barbosa-Cánovas, G.V. (Eds.), Transport Phenomena of Food Processing, pp. 281–290. Naik, L., Sharma, R., Rajput, Y.S., Manju, G., 2013. Application of high pressure processing technology for dairy food preservation-future perspective: a review. J. Anim. Prod. Adv. 3 (8), 232–241. Nguyen, H.A., Anema, S.G., 2010. Effect of ultrasonication on the properties of skim milk used in the formation of acid gels. Innovative Food Sci. Emerg. Technol. 11, 616–622. Nicorescu, I., Nguyen, B., Moreau-Ferret, M., Agoulon, A., Chevalier, S., Orange, N., 2013. Pulsed light inactivation of Bacillus subtilis vegetative cells in suspensions and spices. Food Control 31, 151–157. Nobel, S., Ross, N.L., Protte, K., Korzendorfer, A., Hitzmann, B., Hinrichs, J., 2016. Microgel particle formation in yogurt as influenced by sonication during fermentation. J. Food Eng. 180, 29–38. Orlowska, M., Koutchma, T., Grapperhaus, M., Gallagher, J., Schaefer, R., Defelice, C., 2013. Continuous and pulsed ultraviolet light for nonthermal treatment of liquid foods. Part  1: effects on quality of fructose solution, apple juice, and milk. Food Bioprocess Technol. 6 (6), 1580–1592. Pal, M., 2017. Pulsed electric field processing: an emerging technology for food preservation. J. Exp. Food Chem. 3 (126), 2–3. https://doi. org/10.4172/2472-0542.1000126. Palgan, I., Caminiti, I.M., Munoz, A., Noci, F., Whyte, P., Morgan, D.J., Cronin, D.A., Lyng, J.G., 2011. Effectiveness of high intensity light pulses treatments for the control of Escherichia coli and Listeria innocua in apple juice, orange juice and milk. Food Microbiol. 28 (1), 14–20. Patil, S., Bourke, P., Tiwari, B.K., 2012. Ozone processing of fluid foods. In: Cullen, P.J., Valdramidis, V.P. (Eds.), Novel Thermal and Non-Thermal Technologies for Fluid Foods. Elsevier, London, pp. 225–261. Patterson, M.F., Ledward, D.A., Rogers, N., 2006. Food Processing Handbook. 173. Penna, A.L.B., Subbarao, G., Barbosa-Canovas, G.V., 2006. Effect of high hydrostatic pressure processing on rheological and textural properties of probiotic low-fat yogurt fermented by different starter cultures. J. Food Process Eng. 29, 447–461. Perez, M.P., Aliaga, D.R., Bernat, C.F., Enguidanos, M.R., Lopez, A.M., 2007. Inactivation of Enterobactersakazakii by pulsed electric field in buffered peptone water and infant formula milk. Int. Dairy J. 17 (12), 1441–1449. Pina-Perez, M.C., Silva-Angulo, A.B., Rodrigo, D., Lopez, A.M., 2012. A preliminary exposure assessment model for Bacillus cereus cells in a milk based beverage: evaluating high pressure processing and antimicrobial interventions. Food Control 26 (2), 610–613. Ramos-Villarroel, A.Y., Aron-Maftei, N., Martin-Belloso, O., Soliva-Fortuny, R., 2012. The role of pulsed light spectral distribution in the inactivation of Escherichia coli and Listeria innocua on fresh-cut mushrooms. Food Control 24 (1), 206–213. Ramos-Villarroel, A., Aron-Maftei, N., Martin-Belloso, O., Soliva-Fortuny, R., 2014. Bacterial inactivation and quality changes of fresh-cut avocados as affected by intense light pulses of specific spectra. Int. J. Food Sci. Technol. 49 (1), 128–136.

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Riener, J., Noci, F., Cronin, D.A., Morgan, D.J., Lyng, J.G., 2009. Characterisation of volatile compounds generated in milk by high intensity ultrasound. Int. Dairy J. 19 (4), 269–272. Rivas, A., Sampedro, F., Rodrigo, D., 2006. Nature of the inactivation of Escherichia coli suspended in an orange juice and milk beverage. Eur. Food Res. Technol. 223, 541–545. Rokhina, E.V., Lens, P., Virkutyte, J., 2009. Low-frequency ultrasound in biotechnology: state of the art. Trends Biotechnol. 27 (5), 298–306. Salvia-Trujillo, L., Morales-de la Pena, M., Rojas-Grau, M.A., Martín-Belloso, O., 2011. Microbial and enzymatic stability of fruit juice-milk beverages treated by high intensity pulsed electric fields or heat during refrigerated storage. Food Control 22 (10), 1639–1646. Sampedro, F., Rodrigo, D., Martinez, A., 2011. Modelling the effect of pH and pectin concentration on the PEF inactivation of Salmonella enterica serovar Typhimurium by using the Monte Carlo simulation. Food Control 22 (3), 420–425. Sampedro, F., McAloon, A., Yee, W., Fan, X., Zhang, H.Q., Geveke, D.J., 2013. Cost analysis of commercial pasteurization of orange juice by pulsed electric fields. Innovative Food Sci. Emerg. Technol. 17, 72–78. Sfakianakis, P., Tzia, C., 2014. Conventional and innovative processing of milk for yogurt manufacture; development of texture and flavour. A Review. Foods 3 (1), 176–193. Sheelamary, M., Muthukumar, M., 2011. Effectiveness of ozone in inactivating Listeria monocytogenes from Milk Samples. World J. Young Res. 1 (3), 40–44. Siddique, M.A.B., Maresca, P., Pataro, G., Ferrari, G., 2016. Effect of pulsed light treatment on structural and functional properties of whey protein isolate. Food Res. Int. 87, 189–196. Simpson, S., 2012. Fate of Pathogenic Organisms in a Whey Beverage Treated With High Pressure Processing by a Thesis Submitted to the Graduate Faculty in Partial Fulfillment of the Requirements for the Degree of Master of Science, Iowa State University Ames, Iowa. Smith, W.L., Lagunas-Solar, M.C., Cullor, J.S., 2002. Use of pulsed ultraviolet laser light for the cold pasteurization of bovine milk. J. Food Prot. 65, 1480–1482. Tadapaneni, R.K., Banaszewski, K., Patazca, E., Edirisinghe, I., Cappozzo, J., Jackson, L., Burton-Freeman, B., 2012. Effect of high-pressure processing and milk on the anthocyanin composition and antioxidant capacity of strawberry-based beverages. J. Agric. Food Chem. 60 (23), 5795–5802. Vercet, A., Oria, R., Marquina, P., Crelier, S., Lopez-Buesa, P., 2002. Rheological properties of yoghurt made with milk submitted to manothermosonication. J. Agric. Food Chem. 50, 6165–6171. Villamiel, M., de Jong, P., 2000. Influence of high-intensity ultrasound and heat treatment in continuous flow on fat, proteins, and native enzymes of milk. J. Agric. Food Chem. 48, 472–478. Villamiel, M., Hamersveld, E.H., de Jong, P., 1999. Effect of ultrasound processing on the quality of dairy products. Milchwissenschaft 54, 69–73. Wang, D., Sakakibara, M., 1997. Lactose hydrolysis and β-galactosidase activity in sonicated fermentation with lactobacillus strains. Ultrason. Sonochem. 4, 255–261. Wang, D., Sakakibara, M., Kondoh, N., Suzuki, K., 1996. Ultrasound enhanced lactose hydrolysis in milk fermentation with Lactobacillus bulgaricus. J. Chem. Technol. Biotechnol. 65 (1), 86–92. Wu, H., Hulbert, G.J., Mount, J.R., 2000. Effects of ultrasound on milk homogenisation and fermentation with yogurt starter. Innov. Food Sci. Emerg. Technol. 1 (3), 211–218. Yasothai, R., Giriprasad, R., 2015. High intensity pulsed light technology in food processing. Int. J. Sci. Environ. Technol. 4 (1), 234–236. Yeom, H.W., Evrendilek, G.A., Jin, Z.T., Zhang, Q.H., 2007. Processing of yoghurt based products with pulse electric field microbial, sensory and physical evaluations. J. Food Process. Preserv. 28, 161–178.

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Zheng, L., Sun, D.W., 2006. Innovative applications of power ultrasound during food freezing processes—a review. Trends Food Sci. Technol. 17 (1), 16–23. Zimmermann, U., 1986. Electrical breakdown, electro-permeabilization and electrofusion. Rev. Physiol. Biochem. Pharmacol. 105, 176–256.. Zisu, B., Schleyer, M., Chandrapala, J., 2013. Application of ultrasound to reduce viscosity and control the rate of age thickening of concentrated skim milk. Int. Dairy J. 31 (1), 41–43.

Further Reading Datta, N., Tomasula, P.M., Zisu, B., Chandrapala, J., 2013. Chapter 6: High power ultrasound processing in milk and dairy products. In: Datta, N., Tomasula, P.M. (Eds.), Emerging Dairy Processing Technologies: Opportunities for the Dairy Industry. Wiley-Blackwell Publisher, pp. 115–120. Martinez, F., Desai, I., Davidson, A., Nakai, S., Radcliffe, A., 1987. Ultrasonic homogenization of expressed human milk to prevent fat loss during tube feeding. J. Pediatr. Gastroenterol. Nutr. 6, 593–597. Yu, L.J., Ngadi, M., Raghavan, V., 2012. Proteolysis of cheese slurry made from pulsed electric field-treated milk. Food Bioprocess Technol. 5 (1), 47–54.

RHEOLOGICAL CHARACTERIZATION AND PIPELINE TRANSPORT NEEDS OF TWO FLUID DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

13

Jorge Fernando Vélez-Ruiz Department of Chemical and Food Engineering, Universidad de las Américas Puebla, Puebla, Mexico, Food Network Consulting, S.A. de C. V. Instituto de Innovación y Desarrollo Tecnológico, Puebla, México

Nomenclature CC D Ef f fD fF gc g GHe GRe GRec He k K L n P Pot Pl r R Re t

constant for the Casson equation (F/L2t0.5) tube diameter (L) friction losses energy (FL/M) friction factor (dimensionless) Darcy’s friction factor (dimensionless) Fanning’s friction factor (dimensionless) gravitational constant (ML/Ft2) acceleration due to a gravitational field (L/t2) generalized Hedstrom number (dimensionless) generalized Reynolds number (dimensionless) critical generalized Reynolds number (dimensionless) Hedstrom number (dimensionless) friction loss coefficient consistency coefficient, or model constant for rheological relationships (Ftn/L2) pipe length (L) flow behavior index or in general, power law exponent (dimensionless) pressure (F/L2) pump power (FL/t) plasticity number (dimensionless) radial coordinate (L) pipe inner radius (L) Reynolds number (dimensionless) time (t)

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v X Z

average flow velocity (L/t) milk concentration (% w/w) vertical position (L)

Greek Symbols α ρ

γ τ τ0 τ w μ, η μa μp, ηp

kinetic energy correction factor (dimensionless) fluid density (Μ/L3) shear rate (1/t) shear stress (F/L2) yield stress (F/L2) shear stress at wall (F/L2) viscosity coefficient or absolute viscosity (Ft/L2 or M/Lt) apparent viscosity (Ft/L2 or M/Lt) plastic viscosity (Ft/L2 or M/Lt)

13.1  Dairy Industry The dairy industry as part of the transformation sector of each country plays a very important role in different aspects of the human society. It is important due to the preservation of a biological system, milk, adding value to this food system, supplying important food nutrients, and generating benefits in human health and also improving the economy around the world. The dairy industry provides a great variety of products based on basic concepts to process, preserve, and package them, meeting quality and safety requirements. The milk world production has been augmenting from 1967 to 1969 with 387 × 106 tons, passing to 528 × 106 tons from 1987 to 1989 and 562 × 106 tons from 1997 to 1999, reaching a total of 715 × 106 tons in 2015, and expecting to reach 864 × 106 tons in 2030. It is also expected that the annual consumption of milk and dairy products will increase to 46.5 L per person in 1997–99 and will also increase to 68 L in 2030 in developing countries, in contrast to an average indicator of 219 L in 1997 to 228 L in the industrial countries (FAO, 2015). Thus, the importance of this food system and dairy products is huge. Dairy science and food engineering are two areas of knowledge devoted to develop food products, analyze their composition, design equipment and processes, preserve milk components, optimize milk and dairy items production, guarantee their quality, and satisfy the consumer demands and needs, among other objectives.

13.1.1  Liquids in the Dairy Industry The dairy industry must develop, engineer, supervise, and design safe and attractive products, efficient equipment, and proper ­processes, by taking, controlling, and inspecting the raw material,

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checking the correct operation parameters that guarantee the quality of the final products. Since the beginning and through the whole process operations, most of the materials are handled in liquid form. Even though some process operations are incorporated in food products manufacturing, in order to get a liquid material, such as the case of agitation, mixing, and fluidization for instance, liquid transportation is one of the most frequently utilized. Thus the transportation of water, milk, cream, concentrated milk, ice cream, fermented milk beverages, and complementary liquid ingredients, among others, is a very important part of the dairy industry. In the preparation of most of the dairy products, the handling and transportation of fluids are really important and transcendent to reach the final product. Milk, intermediate, and final products are liquids with a particular characteristic; most of them behave as nonNewtonian fluids (NNFs); therefore additional information about Newtonian fluids (NFs) handling and transportation should be known and considered for process design.

13.1.2  Transportation of Liquid Foods and Pumping Needs Considering that milk, cream, yogurt, and other dairy products implies the handling and transportation of liquid foods in some stage of the overall process transformation. There exists an enormous necessity for fundamental and right knowledge about fluid characteristics, they have been researched, studied, and analyzed by many people due to the importance of this industrial task and concern. But still is a topic for more research and development. The subject of fluid flow as an outstanding and frequent unit operation is of great importance in most of dairy processing plants. This food process operation involves a considerable number of fundamental concepts that must be known and understood, to be able for design of a specific transport system, where the pumping needs play an outstanding role. Engineer activity that is complicated by the NNF flow behavior, therefore the dairy liquids cannot be treated as fluids similar to water. A common transportation system for liquid foods includes five basic elements, (i) tanks, a tank for liquid feeding, another tank for reception, tanks for an intermediate stage or storage, among others; (ii) pumps, where the centrifugal ones are the most frequently used in the food industry; (iii) stainless steel pipeline as the hygienic transport or conducting material for the milk fluids; (iv) fittings that play specific roles, such as control of volumetric flow by valves (gate, globe, angle, three way, etc.), change in diameters (contraction or enlargement) or change in flow direction (elbow, tee), for instance; and (v) measuring devices such pressure gauges, flow meters, and thermometers (Vélez-Ruiz, 2017a).

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All of them, and other additional equipment, such as filters, heat exchangers, other processing units, may be used in several configurations depending on the specific characteristics of the dairy production process. It is essential that the whole components of the system contribute to sanitary transporting and right handling of the milk items.

13.2  Fluid Milk and Dairy Products 13.2.1  Milk Characteristics Although milk has the appearance of a simple liquid, its structure is very complex and not even fully known. Chemically, milk is a complex material integrated by several hundreds of constituents, many of which have special significance even though some of them are present in very low concentrations. In general, the components of milk are classified into seven groups: proteins, lipids, carbohydrates, minerals, pigments and vitamins, enzymes, and miscellaneous compounds (Alais, 1985; Smit, 2003; Vélez-Ruiz, 2017b), its nutritional richness is due to the fact that the primary purpose is to provide food to the calf. This simple liquid is an interesting mixture of interactions, it is a complex solution of salts, lactose, and other hydrophilic minor components wherein, whey proteins, casein micelles, and fat globules are dispersed (Kalab, 1993; Smit, 2003; Vélez-Ruiz, 2017b). And the dispersed phase represents two separate colloidal forms: proteins in a suspension and fat in an emulsion state. Milk contains seven-eighths of water and in the rest, one-eighth, are the three main constituents, fat, lactose, and protein; they are present in very roughly equal quantities by weight. Liquid milk may be considered a NF, but several of the dairy products obtained from it, behave as non-Newtonians. Furthermore, the transformation process may produce viscoelastic items, such as custards and cheeses, or solid products such mature cheese and milk powder. In all of them the rheology and texture of each item is very important and with different physical properties. As a raw material, milk is transformed for preservation purposes and subsequent commercialization taking numerous and different presentations. Dairy products include a diverse group of foods made from milk, such as flavored beverages in which attractive flavors, vitamins, and minerals are incorporated; those in which native or added microorganisms metabolize some of the milk components generating the group of the fermented milks, yogurt being the most commercially known; a fatty group in which fat is the main component, including cream, butter, and ice cream; another one in which protein is the important modified component, such as dairy custards and cheeses; and concentrated and dry milk, which are transformed and preserved by

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elimination of water, from whole or skim milk. Of course, there are some by-products that are less marketable. Thus, dairy products are very important from a nutritional, technological, and economical viewpoint. Nutritious and functional foods are now consumed as part of a normal diet, providing a specific physiological function. The dairy industry is widely interested in the functionality of milk products, due to their beneficial effects on human health, increasing dairy products consumption significantly around the world (Miller et al., 2000; Macedo-y-Ramírez and Vélez-Ruiz, 2015).

13.2.2  Flavored Milks, Elaboration, and Characterization Flavored milks are dairy products for direct feeding and are common in many countries in which certain population groups, babies, kids, and old people have been groups protected through these products. A variety of flavors and presentations of milk drinks are available in the market. Flavored milk has the potential to increase children’s consumption in school and home. In pasteurized and ultrahigh-­ temperature milks, processors have included different flavors such as chocolate, strawberry, coffee, banana, and “cajeta,” among others. Nevertheless, chocolate-flavored products are still the most popular ones; they are formulated with ingredients such as milk, sucrose, cocoa powder, and some hydrocolloids that are added to improve consistency and to prevent sedimentation of cocoa particles; all these ingredients cause variations in physicochemical, flow, and sensory properties of the formulated product and in the consumer acceptance. The development of new milk drinks creates an alternative to fluid milk and chocolate-flavored milk products. The use of caramel jam in formulations of flavored milk drinks offers more opportunities for new and different products in the world (Ramírez-Sucre and VélezRuiz, 2011). These dairy products are obtained from cow’s milk, which has been inspected and standardized in order to meet the proper requests for a pasteurized flavored beverage. The most important unit process is mixing and agitation where the ingredients are combined and the solids content are reached, then liquid transportation up to the heat exchanger unit where thermal treatment is given to ensure the elimination of pathogen microorganisms, and normally after pasteurization the milk is homogenized. If the flavor and some fortification ingredients were not added previously, the pasteurized-homogenized milk would be exposed to another mixing and agitation stage into another process tank in order obtain the flavored beverage that finally is cooled and packed in marketable specific packages.

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13.2.3  Yogurt Elaboration and Characterization Yogurt is a dairy product extensively manufactured by the dairy industry, being a highly consumed item due to its healthy nature and accessible manufacturing process. The health attributes of yogurt are due to the presence of lactic bacteria and calcium content. Some desired effects of yogurt on human health have been identified as anticancer nature, antimicrobial activity, cholesterol reduction, immunity, and lactose digestion, a diversity of studies supporting these benefits (Tamime and Robinson, 2007; Vélez-Ruiz, 2008, 2017b). Yogurt is a protein network formed by casein micelles entrapping serum and fat globules. The casein framework of yogurt is relatively weak, although the formulation and processing affect the microstructure; consequently, the distribution of the other components has an important effect on the flow behavior. The microstructure composed of casein micelle chains and clusters is similar for manufactured yogurts, but the way in which casein micelles are linked to other components is noticeably different depending on the transformation process (Kalab, 1993; Tamime and Robinson, 2007). Yogurt manufacturing may include many processing variables and characteristics, but it involves three main steps: (i) standardization of the milk in which all the ingredients are mixed inside an agitated vessel; (ii) heat treatment for milk pasteurization and whey protein denaturation; (iii) fermentation stage, where two typical lactic bacteria Lactobacillus bulgaricus and Streptococcus thermophilus are inoculated; and (iv) additional modifications such as casein destabilization, gelation, and matrix formation are developed. The gel structure reached through the whole process will determine consumer acceptance (Vélez-Ruiz and Rivas, 2001; Kessler, 2002; Tamime and Robinson, 2007; Vélez-Ruiz, 2008, 2017b; Macedo-y-Ramírez and Vélez-Ruiz, 2015). Yogurt is on the market in two forms: set and stirred types; in the former, the gel structure is developed during the fermentation stage inside the container, while in the latter the structure formed during the bulk incubation is broken down through the shear rates applied by agitation to generate a semi-viscous yogurt (Vélez-Ruiz and BarbosaCánovas, 1997; Tamime and Robinson, 2007; Vélez-Ruiz, 2008; VélezRuiz et  al., 2012; Santillán-Urquiza et  al., 2017). Observations made with electron microscopy have revealed the microstructure of set yogurt as an uninterrupted three-dimensional network composed of chains and clusters of casein micelles; on the other hand, stirred yogurt showed fewer chains and more clusters of micelles joined together by fibers (Kalab, 1993; Ramírez-Sucre and Vélez-Ruiz, 2013; Santillán-Urquiza et al., 2017). In general terms, for any type of yogurt, there is a close relationship between consistency and quality, though contradictory responses have resulted when sensory evaluation has

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been involved, due to the differences in human perceptions. Overall, three approaches have been proposed for improvement of body, texture, and increasing viscosity of the yogurt by (1) increasing total solids, (2) the addition of stabilizers, and (3) the control of processing time and temperature (Vélez-Ruiz and Rivas, 2001; Tamime and Robinson, 2007; Vélez-Ruiz et al., 2012; Vélez-Ruiz, 2008, 2017b). Fig. 13.1 presents three micrographs of flavored yogurt with cajeta or caramel jam at different concentrations (10% and 15%) without gum from whole milk (3.2% fat), and skim milk (0.2% fat). Furthermore, yogurt flow properties, microstructure characteristics, sensory attributes, viscoelasticity, and water-holding capacity may be affected by many factors; some of them are the formulation process in which the incorporation of total solids, proteins, and thickeners has been considered to augment consistency, viscoelasticity, and to decrease syneresis. Other modifications in the formulation, such fat and sugar decrease, nutrients fortification (Ca, Fe, Zn), fiber adding, or solids modifications, produce varied effects; all these components try to improve consistency and reduce whey separation, as well as provide nutritious value (Vélez-Ruiz and Barbosa-Cánovas, 1998; Vélez-Ruiz et al., 2012; Macedo-y-Ramírez and Vélez-Ruiz, 2015; Santillán-Urquiza et al., 2017). Each of the manufacturing sequences will play an important role in yogurt properties; then, shear stresses during mixing, homogenization, pipeline transporting, and pumping; temperature changes through heating and cooling, and process times should be taken into account, among others.

13.2.4  Other Fluid Milk Products Other dairy products that have fluid consistency are the fermented items different from yogurt, ice cream, and butter at certain temperatures of heating, and concentrated and evaporated milk at various levels of solid concentration.

13.3  Fluid Dynamics and Rheology 13.3.1  Newtonian (NF) and Non-Newtonian Fluids (NNFs) Liquid foods handling, pumping, and transportation are phenomena or unit operations studied and analyzed by fluid dynamics that requires regarding the flow properties knowledge of both NF and NNFs. An NF is a fluid with constant viscosity just affected by temperature and concentration, whereas an NNF is that fluid, particularly a liquid, with an apparent viscosity that is not constant and varies as a function of the applied shear rate-shear stress range, being also affected by

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Fig. 13.1  Microstructure of flavored yogurt with different formulations (A) 0.2 fat-0 gum15 cajeta, (B) 3.2 fat-0 gum-10 cajeta, (C) 3.2 fat-0 gum-15 cajeta. The scale bars denote 50 μm of length (350×).

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concentration and temperature. The apparent viscosity of NNF may be measured at a particular shear rate, 50 s−1 for instance, or at a specific range of shear rate when the flow response or rheogram is known or needed. Dairy foods as raw materials are normally transported and processed in liquid form due to facility of handling, and only a minor part of the manufacturing is related with solid items; certainly many dairy products are in solid or semisolid state (Rao, 1999; Kessler, 2002; Vélez-Ruiz, 2013, 2017a,b). Liquids and semisolids may exhibit Newtonian, plastic, rheopectic, shear thinning, shear thickening, thixotropic, as well as viscoelastic behavior in which flow properties like viscosity, flowability, pourability, flow behavior index, consistency coefficient, yield stress, storage modulus, elastic modulus, and stress relaxation, among others are indispensable for their identification and characterization. They may be objectively characterized by steady shear tests with a rheometer or viscometer instrument. Similarly, solid and semisolid foods may show creep compliance, relaxation profile, plastic, viscoelastic, or inelastic nature that are characterized by strain or stress as a function of time, a phase angle, and different moduli by dynamic determinations with a texturemeter or a rheometer. Furthermore, solids characterization of texture and measuring of textural attributes are frequently needed and utilized with practical purpose. Determination of the rheological properties of foods, from the simplest to the most complex, is necessary at different stages of dairy food transformation, storage, and consumption. These needs include from the transportation from the ground or farm as far as the final product, passing by the quality attributes, and finalizing with those dairy items ready to be eaten by an exigent consumer. To get the rheological properties of each product, it is necessary to know some fundamental physical measures that are obtained with rheometers, texturemeters, and/or viscometers. In addition, rheometry in conjunction with mathematical modeling permits attainment of flow equations. They are applied into food processes involving momentum and heat transfer phenomena, and with less frequency into mass transfer operations.

13.3.2  Pipeline Design and Pumping Power Even though there are several studies on flow properties of NNF and of course, many on NF and their transportation, design, and pumping through pipelines, the research works related with NNF are really scarce. One of the flow parameters particularly useful for food liquid transportation is the viscosity for NF, and the flow behavior index, yield stress, and consistency coefficient or apparent viscosity for NNF. Food liquids may be moved or handled through pipelines at the laminar regime most frequently for NNF, or at the turbulent regime

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most frequently for NF. The advancements in research when a NNF is transported through a particular system will be briefly presented ahead.

13.3.2.1  Dimensional Analysis As a first approach to visualize the grouping of variables for a specific transformation process, from the physical and mathematical points of view, is the dimensional analysis (DA), in which dimensions, in this case, of the transporting system and properties of the food fluid to be transported are required. They are tube diameter, average velocity, density, viscosity or flow parameters, surface roughness, pressure drop or head loss, heights, and pumping power; other parameters should be included depending on the specific process operation or the difficulty degree of analyzes. The DA methodology may be utilized, but it only generates groups of variables without numerical coefficients that should be experimentally obtained (Welty et al., 1976; Foust et al., 1980; Ibarz et al., 1994; Ibarz and Barbosa, 1999; McCabe et al., 2001; Geankoplis, 2006; Toledo, 2007; Pawlowski, 2013; Vélez-Ruiz, 2017a). From the DA application, important and useful dimensionless groups, also known as numbers or moduli, may be generated; some examples of them are the friction factor, relative length, Reynolds, relative roughness, generalized Reynolds, plasticity, Hedstrom, and more (VélezRuiz, 2003, 2017a); then experimental information will complete the utility of this procedure. First, the application of DA to obtain a relationship for the friction energy losses expressed by mean of a dimensionless group (ff) may be and has been studied and evaluated carrying out experimental investigations. It includes pressure drop (ΔP), average velocity (v), density and the constant of gravity (gc), and with advances in its knowledge, it may be modeled or computed as a function of other different dimensionless groups. For example, the relative roughness (ε/D) and Reynolds number (Re) for NF; the flow behavior index (n) and generalized Reynolds number (GRe) for dilatant and pseudoplastic fluids, while the generalized Hedstrom (He), plasticity (Pl), and GRes should be involved for plastic fluids, including both the Herschel and Bulkley (HB) and the Bingham Plastic (BP) liquids, depending on the flow index (Ibarz et al., 1994; Ibarz and Barbosa, 1999; Singh and Heldman, 2001; Pawlowski, 2013; Vélez-Ruiz, 2003, 2017a,b). ff =

∆Pg c   = f  ,Re ,n ,GRe ,GHe ,Pl  ρv 2 D  

(13.1)

13.3.2.2  Mechanical Energy Balance The other and commonly applied one is a very practical approach that is known as the Bernoulli equation (BE) that was conceived as

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   437

an expression of the first law of thermodynamics or mechanical energy balance. It has been frequently used as the application to steady, incompressible, and isothermal flow, for ideal or NFs with constant viscosity (Welty et al., 1976; Heldman and Singh, 1981; McCabe et al., 2001; Geankoplis, 2006; Toledo, 2007; Vélez-Ruiz, 2017a). This approach was lately completed by inclusion of some correction factors, one for the kinetic energy and another one for the pumping work; thus, the energy needs and pumping power for the food transport system may be computed accurately. Consider a typical system (Fig. 13.2), with all the necessary elements for fluid transportation, in which there are no changes in temperature, involving mechanical energy and pumping work. Furthermore, an incompressible fluid and a steady process are considered; thus, the first law of thermodynamics application is simple and practical. Therefore in this common system, the fluid position (Z), the average fluid velocity (v) in different sections or pipeline diameters, with its entry and exit pressures (P), its viscosity and the shaft work supplied by the pump, which are the main types of energy, should be considered. Then the equation or model to quantify all these types of energy is the famous and practical BE (Charm, 1971; Welty et al., 1976; Foust et al., 1980; Ibarz and Barbosa, 1999; McCabe et al., 2001; Singh and Heldman, 2001; Vélez-Ruiz, 2003; Geankoplis, 2006; Toledo, 2007; Vélez-Ruiz, 2017a). The present mechanical energy balance is an equation expressed by unit mass, in which some correcting terms have been included, as was aforementioned. The first is related with the local/average velocity or velocities profile inside the pipeline and the second is related with the pump performance, in which the mechanical efficiency is considered. However, the third is related with friction/viscous energy, where the main drop is due to wall friction, some additional elements should be considered; there are frictional losses when the fluid is forced to the entrance, when a change of diameter is present, as well as the fittings that are very appropriate for flow controlling and handling of the food fluid; in addition there may exist process equipment (Fig. 13.2), such 2 Supply tank with the fluid (3 m), connected to 1.5 diameter

1

Outlet with a globe valve of 2.0, 9 m height

Process equipment with a pressure drop

Fig. 13.2  Schematic diagram of a transport system for food fluids.

438  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

as a filter, a deaerator, or a heat exchanger, that is placed between the supply and delivery points generating a pressure loss. All these terms/ energies are included into the next relationship: P1 v2 P v2 g g + Z1 + 1 +  Wp = 2 + Z 2 + 2 + E f ρ ρ g c 2α g c g c 2α g c

(13.2)

where P is the absolute pressure (Pa), ρ is the liquid density (kg/ m3), Z is the relative height or position (m), g is the gravity acceleration (9.81 m/s2), gc is a dimensional constant related with gravity acceleration (1 kg m/N s2), v is the average velocity (m/s), α is a kinetic c­ orrection factor (dimensionless) due to the fact that the local velocity inside the pipeline is not the same for all the radial positions (r), ϵ is the mechanical efficiency of the pump (dimensionless and lower than 100%), Wp is the pumping work or energy used to move the fluid from the entrance (1) to the exit (2), and Ef is the energy losses due to the viscosity of the fluid and the friction through the pipeline and fittings. All the terms are grouped as inlet energy (left side of the pump, with number 1) and outlet energy (right side of the pump, with number 2), and each term is expressed in energy per unit mass (J/kg). And to get the power of the pump (Pot), the shaft work should be converted to energy per second (W), as is obtained from Eq. (13.2) by taking the mass flow (ω, kg/s): Pot = ωWp

(13.3)

13.4 Rheology 13.4.1  General Aspects Rheology, defined as the science of flow and deformation of material, is a fundamental interdisciplinary science that has been gaining more and more importance and utility in the food fluids characterization and particularly in the field of dairy foods. According to Steffe (1992), Rao (1999), Morell et al. (2015), Vélez-Ruiz (1996, 2003, 2009, 2017a), among other authors, there are numerous topics of interest for the food industry related to rheology, such as: (a) process engineering applications for equipment and process design, (b) development of new products or reformulation, (c) quality control of intermediate and final products, (d) understanding of food structure, and (e) correlation with sensory evaluation. Rheology can be used to characterize flow behavior, but also the structural characteristics, of biological and inorganic materials. Insight into the food structural arrangement helps to predict the behavior or

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   439

stability of a given material with storage, change in humidity, temperature, and handling. Flow properties, such as consistency coefficient, flow behavior, pourability, texture, thickness, viscosity either absolute, apparent or plastic, and yield stress, contribute substantially to facilitate pipeline transport and commercial processing, as well as to promote consumer acceptance. Further viscoelasticity characteristics, such as loss and storage moduli and phase angle, among others, help very much to understand the food nature, temperature effects, component interactions, and phase transformations (Aportela-Palacios et al., 2005; Vélez-Ruiz, 2013, 2017a). Rheology may be utilized and applied widely in many areas of the industry, not only for foodstuff, but also for biological, inorganic, and complex materials. Consequently, basic rheological information of materials is important not only for engineers, but also for processors, food scientists, and people who are related with the food industry. The evolution of rheology is related to important contributions of outstanding scientists: Newton, Kelvin, Maxwell, Einstein, Flory, de Gennes, and Chu, among many others (Rao, 1999; Vélez-Ruiz, 2017a) and many studies have been carried out on dairy foods in the past three decades that have contributed to the knowledge of dairy science.

13.4.2  Instrumentation in Rheological Characterization Any instrument utilized to characterize the physical response of a given food item is able to measure forces, stresses, torques, deformations or deformation rates as a function of time commonly, or as a function of other variables, such shear rate, deformation, frequency, and temperature, among others. The fundamental properties of dairy products are independent of the measuring instrument in which they are characterized; therefore, different instruments will generate the same final results; but some advanced devices facilitate the rheological determinations to a great extent. Even though there is a wide array of instruments, including the empirical and fundamentals device systems, only a few characteristics of fundamental instruments are presented, without minimizing the importance and practicality of the empirical ones. Common and commercial instruments, capable of providing fundamental determinations, may be divided into two types: rheometers and viscometers used to characterize the physical response of fluids and semisolids foods, whereas texture analyzers are employed to test mainly the nature of solid and semisolid food items. Fluid testing instruments may be grouped in two categories taking the basic supporting geometry: tube type and rotational type. In the first group, the basic determinations of pressure drop and volumetric flow are converted

440  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

into shear stress and shear rate, respectively; these viscometers are simple devices in which a cylindrical tube is the important element and may be fabricated on site. However, in rotational instruments the torque is transformed into shear stress, and the rotational velocity is utilized to compute the shear rate taking into account the geometry dimensions; most of the rotational devices are marketed with a computer software unit by specialized commercial brands. Costs vary tremendously from the inexpensive glass capillary and tube viscometers to very expensive stress control rheometers. The main geometries utilized in measuring instruments, under steady shear and dynamic conditions, are concentric cylinder, cone and plate, parallel plate, agitators with different arrangements, capillary at atmospheric and high pressure, piston and cylinder in extrusion, and tubes; and others are minimally used. Rheometers: These instruments allow continuous determinations, commonly at a selected shear rate, at ascendant and descendent loops, and less frequently at a given shear stress. The time of testing may be short or long, allowing flow characterization of both behaviors: time independent and time dependent. They can be used in dynamic mode, in which a sinusoidal varying stress or strain is applied for characterization of dairy foods from the viscoelastic viewpoint. Rheometers have become widespread nowadays. Commercial rheometers have incorporated constant improvements and technological advances and larger memories, digital processors, and microprocessors (Vélez-Ruiz, 2013, 2017a). In addition, a significant growth in the utilization and analysis of complex geometries as part of the rotational rheometry, like vane and helical, to overcome measurement limitations found in conventional rheometers and fluids has been recognized. Vane methodology has been recognized as a reliable and an easy method for rheological characterization of concentrated suspensions (Rao, 1999; Martínez-Padilla and Linares-García, 2001; Vélez-Ruiz, 2013, 2017a). Viscometers: They are single instruments in which the basic geometry is a couple of concentric cylinders (the cup or sample container and the bob or rotational device) and are capable of providing readings, normally with low torques and rotational velocities, which can be converted to shear stress and shear rate, respectively. These instruments are unable to complete dynamic performances and are economical. Some instruments for the rheological characterization of food fluids and their basic characteristics are included in Table 13.1. To complete flow determinations with rheometers and viscometers, some general assumptions are considered: (i) the liquid is incompressible, (ii) the regime of the flow is laminar, (iii) the steady flow implies only a velocity component as a function of the radius, neglecting other velocity components, (iv) there is no slippage phenomenon, (v) final and edge effects are neglected, and (vi) the experiment is conducted at the isothermal condition.

Table 13.1  Important Characteristics of Some Rheological Instrumentsa Instrument/ Geometry

Costs ($US)

Commercial Brands

Capilar Viscometers

Cheap 50–600

Cannon-Fenske Ostwald

D: 0.1–3 mm

Fittings increase the costs Cheap 1000–3000

Schott Wescan Yourself manufacture and detailing

For NF and NNF High shear stresses

Fito et al. (1983) Vélez-Ruiz (2017a)

Intermediates 1500–7500

Brookfield Ofite Haake Contraves

Meanly for laboratory, quality control

Brookfield (2017) Vélez-Ruiz (2017a)

Tube Viscometers D: 2–20 mm Versatile and single Viscometers

Characteristics and Determinations NF viscosity Cleaning of the capilar is very important

Steffe (1992) Rao (1999) Vélez-Ruiz (2017a)

New designs for process plants Advanced control and software. High shear deformations. Able for dynamic tests

Rotational

Expensive

Reometers (in general)

25,000–120,000

Control stress Rheometer

Expensive 45,000–150,000

Haake Paar Physica TA Instruments Haake Paar Physica

Rheometers with mixer agitators

Expensive

Fluids with particles

Controlled and low stresses Magnetic support Temperature control Specific designs

60,000–150,000

Maybe designed and manufactured

Temperature control

D, diameter; NF, Newtonian fluid; NNF, non-Newtonian fluid. a For more practical, specific, and exact data, the manufacturing companies should be consulted.

References

Anton Paar (2016) TA Instruments (2015) Vélez-Ruiz (2017a,b) Holdsworth (1993) Vélez-Ruiz (2017a) Steffe (1992) Vélez-Ruiz (2017a)

442  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

Texturemeters: These are instruments that allow the characterization of texture and/or textural identification of solid foods mainly of any type through mechanical loading. These instruments may display the viscoelastic characterization through creep and stress relaxation tests. Of course, some measures on dairy foods may be carried out with these instruments. Textural parameters such as adhesivity, compression, and penetration, allowing the determination of various moduli, may also be characterized in a texturemeter; but normally they are not able to carry out a complete flow characterization. The choice of the instrument to be utilized depends on the nature of the dairy product and the properties that need to be known on the one hand, and on the other, the measuring capacities of the equipment. As fluid materials, and based on the objective determinations and influence of time, dairy liquids may be classified into two groups, as independent of time and dependent of time. Time-independent characterization is the most frequently used to identify their flow nature and to fit the response to a mathematical model, whereas time dependency is quite important for some structured foods; this second group is divided into thixotropic and rheopectic behaviors. The rheograms corresponding to independent flow responses are schematized in Fig. 13.3A. Viscoelastic characterizations of dairy products are gaining importance and a lot of studies have been carried out in the past years.

13.4.3  Rheological Fitting For the flow characterization or rheological modeling of a great diversity of foods with time-independent non-Newtonian behavior, several instruments have been applied and mainly identified by their basic geometry, as tube and rotational types. The rheometers more commonly utilized and commercially found with their rotational fixture, are Haake, Brookfield, Carri Med, Rheometric, Physica, TA Instruments, and Anton Paar, just to mention some of the commercial ones. However in tube viscometers, the capillary ones may be commercially handled, while the tube viscometer may be designed and manufactured by using the basic elements. Physical properties such as consistency, curd tension, firmness, flow properties, viscoelasticity, and texture of yogurt, have been satisfactorily measured and employed for consumer satisfaction because they can be related to sensory acceptability. Particularly, the rheological properties of dairy beverages and yogurt are dependent on variables, such as milk composition, previous and manufacturing treatments (cooling, heating, homogenization), total solids, culture type, acidity, proteolysis degree, and final manufacturing steps (agitation, mixing, pumping, refrigeration), among others.

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   443

Plastic (HB) NF t (Pa)

Plastic (PB) Pseudoplastic (PL)

t0

Dilatant (PL)

(yield stress) g (l/s)

(A) 1.2

Shear stress (Pa)

1 0.8 0.6 0.4 0.2 0

(B)

0

5

10

15

20

25

30

35

Shear rate (1/s)

Fig. 13.3  Rheograms for NF and NNF. (A) General representations for fluids responses and (B) experimental results for yogurt systems with cajeta.

Since the 1970s, many works on rheological behavior and modeling have been developed to fit the non-Newtonian and/or viscoelastic behavior of dairy products. There are other studies characterizing the dynamic behavior of milk fluids, and only a few of them in which the thixotropic nature of this milk items has been obtained. Due to the network structure of some dairy products such as yogurt, which plays an important role in the viscoelasticity of these products, dynamic tests are finding an excellent field of application, to follow the gelation and structural breakdown phenomena (Aportela-Palacios et al., 2005; Ramírez-Sucre and Vélez-Ruiz, 2013; Ramírez-Sucre et al., 2014; Morell et al., 2015; Vélez-Ruiz, 2017a).

40

444  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

From the experimental data (shear stress or viscosity vs shear rate), the rheological mathematical models may be applied to fit the particular flow response; they represent a good number, in which there are three or four of them. They have a wide range of utility in the food science/engineering field allowing to characterize the flow behavior (Steffe, 1992; Ibarz and Barbosa, 1999; Singh and Heldman, 2001; Ramírez-Sucre et al., 2014; Vélez-Ruiz, 2013, 2017a). The most useful equations in food rheology are: The Newton equation (NE) for NFs

τ = µγ

(13.4)

The power law or Ostwald-De Waele model (PL, n ≠ 1.0), for pseudoplastic or shear thinning and dilatant or shear thickening fluids, with absence of a yield stress,

τ = Kγ n

(13.5)

The BP model (n = 1.0), for plastic fluids or fluids with presence of a yield stress, in which the plastic viscosity is constant

τ = τ 0 + µp γ

(13.6)

The HB model (n ≠ 1.0), for plastics of two types: pseudoplastic and dilatant fluids,

τ =τ 0 + Kγ n

(13.7)

where τ is the shear stress (Pa), μ is the absolute viscosity or viscosity (Pa s), γ is the shear or deformation rate (s−1), K is the consistency coefficient (Pa sn), n is the flow behavior index (dimensionless), τ0 is the yield stress (Pa), and μp is the plastic viscosity (Pa s). Table 13.2 shows some examples of food fluids, their flow properties, and additional information that is useful and allows us to know the nature or type of response, by taking care of the flow behavior index value. NF have n = 1; in contrast, NNF exhibits n different to 1, being of pseudoplastic behavior when n  1 (a behavior rarely found in food fluids) and corresponding to the plastic behavior of those food fluids exhibiting a yield stress value, in which again a food fluid may be differentiated based on the flow index consideration; with n ≠ 1 the flow response may be fitted by the HB model, whereas with n = 1 the flow response may be fitted by the PB model. In Table 13.2, the first eight examples are Newton fluids in which the flow behavior index is equal to 1, whereas the next five food items are power law fluids, with n ≠ 1; further the last three products are HB fluids (n ≠ 1 and τ0 > 0); and none of the BP fluid was included. Other rheological models such as Ellis, Sisko, Cross, Carreau, Casson, and Vocadlo (Steffe, 1992; Rao, 1999; Vélez-Ruiz, 2008, 2013, 2017a), among others, have been just applied for particular types of food fluids.

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   445

Table 13.2  Flow Parameters for Some Food Fluids at Different Conditions and Temperatures Food

Flow Index

Flow Properties

Water Corn oil Sucrose solution Sucrose solution Sucrose solution Honey (18%) Raw milk (20°C) Raw milk (30°C) Guacamole Pulque Concentrated milk

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.83 1.69 0.96

μ = 1 mPa s μ = 56.5 mPa s μ = 1.967 mPa s μ = 6.223 mPa s μ = 56.7 mPa s μ = 4800 mPa s μ = 1.99 mPa s μ = 1.49 mPa s K = 24 Pa sn K = 2.00 mPa sn K = 26.0 mPa sn

Yogurt (with fiber)

0.63

K = 1.50 Pa sn

Milk dessert Mandarin juice

0.57 0.71

Milk beverage

0.75

Custard (5°C)

0.69

K = 10.5 Pa sn K = 4.16 Pa sn τ0 = 1.78 Pa K = 29 mPa sn τ0 = 30 mPa K = 1.98 Pa sn τ0 = 13.86 Pa

Reference

Comment

Steffe (1992) Steffe (1992) Steffe (1992) Steffe (1992) Steffe (1992) Steffe (1992) Vélez-Ruiz (2013) Vélez-Ruiz (2013) Vélez-Ruiz (2017a,b) Vélez-Ruiz (2017a,b) Vélez-Ruiz and BarbosaCánovas (1998) Aportela-Palacios et al. (2005) Morell et al. (2015) Falguera et al. (2010)

NF, ideal behavior NF, 25°C NF, 20% w/w, 20°C NF, 40% w/w, 20°C NF, 60% w/w, 20°C NF, white Clover 25°C NF, non-pasteurized NF, non-pasteurized NNF, avocado puree NNF, Mexican alcoholic beverage NNF, 30.5% w/w

Ramírez-Sucre and Vélez-Ruiz (2011) Vélez-Ruiz et al. (2005)

NNF, flavored with cajeta

13.5  Experimental Characterization of the Two Milk Products Just to have an idea of the research on both dairy products’ preparation and characteristics, brief information of the flavored milk beverage and yogurt is given.

13.5.1  Products Preparation 13.5.1.1  Beverage and Yogurt Ingredients Three types of milk powder, whole (Nestle Nido, Mexico), skim (Svelty, Nestlé, Mexico), and light were utilized; the light milk was

NNF, and calcium NNF, low concentration NNF, concentrate at −3°C

NNF, with whole milk

446  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

obtained by a mixture (50% w/w) of skim and whole milk powders. Kappa-carrageenan gum (Veyco, Mexico) and Mexican cajeta (caramel jam, Real Potosí, Mexico) completed the ingredients. However, a lyophilized mix of L. bulgaricus and S. thermophilus (Danisco, Mexico) was used as starter culture for yogurt fermentation.

13.5.1.2  Beverage and Yogurt Milk beverages were prepared by dissolving milk powder (0.1%, 1.6%, or 3.2% of fat content) in deionized water at room temperature. The kappa-carrageenan powder (0%, 0.02%, or 0.04%) was added by agitating for 5 min. Then samples were heated at 75°C for 20 min under constant agitation in order to disperse the hydrocolloid and milk powders. Finally, the cajeta was added to the solution with selected concentrations (8%, 10%, or 12%) under constant agitation for 5 min. Yogurt samples were prepared by dissolving the gum powder (0.02%) in deionized water at 60°C, and then 10% of milk powder was added and homogenized by mechanical agitation. The samples were heated up to 90°C for 15 min and then cooled down by a water bath to 47°C. The milk was inoculated with 2% of microorganisms mix to start the fermentation process; all samples were kept at 37°C up to reach a pH of 4.5 (6 h, approximately). Subsequently, the caramel jam was added at selected concentrations (10.0%, 12.5%, or 15.0%) at the incubation temperature. The homogenization of the mix and breakdown of the yogurt gel were carried out by mechanical stirring (Brawn, Mexico). A total of 300 mL of samples were prepared to complete all the analyses, and packed in plastic containers. The yogurt samples were stored under refrigeration (4 ± 1°C).

13.5.2  Instrumental Determinations All physicochemical determinations were completed by following official laboratory procedures; thus, the acidity, Brix degrees, color, density, and moisture were measured. Flow measurements for the flavored beverages were carried out in a Brookfield concentric cylinders viscometer (LVDE115 Brookfield Engineering Laboratories Inc. Middleboro, MA) using a UL Adapter type stainless steel 304 consisting of a spindle, a sample tube, mounting channel, coupling nut, extension link, and an end cap. Shear stress was determined at shear rates of 1, 2, 3, 4, 5, 10, 20, 30, 50, 60, and 100 rpm with a ramp of 120 s. Measurements were done in duplicate at room temperature (25 ± 1°C) on days 1, 7, 14, and 21, with 16 g of sample stored under refrigeration (4 ± 1°C). Experimental data were fitted to the HB model and the three parameters, yield stress, flow index, and consistency index, were used to characterize the flow properties of samples and the viscosity values. Yield stresses were calculated from

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   447

the Casson model (τ0.5 = τ00.5 + CCγ0.5) and the apparent viscosities were computed from the expression η = τ/γ. The flow measurements for the yogurt systems were determined with a Brookfield concentric cylinder viscometer (LVDVIII, Brookfield Engineering Laboratories Inc., Stoughton, MA, USA). The measurements were carried out in duplicate using a small sample adapter (SSA) and SC4-31 needle (input code 31) to 10 mL of the sample at 15°C on days 0, 7, 14, and 21, at speeds of 10–100 r.p.m., and the corresponding shear stresses were recorded. The experimental data were fitted to the HB model; thus, yield stress (τ0), flow behavior index (n), and consistency coefficient (K) were used to characterize the flow response of the yogurt samples. The yield stress values were calculated using the Casson model (τ0.5 = τ00.5 + CCγ0.5); then, a linear correlation of log (τ − τ0) vs log γ was applied for the determination of flow behavior index and the consistency coefficient, τ being the shear stress, γ the shear rate, and C a constant in the Casson equation. In addition, a nonlinear correlation (data not included) for the HB equation was tried by using the Kaleidagraph (Synergy Software, Reading, PA) software. Fig. 13.3 includes the rheograms that are used as general representations for the fluids flow characterization (Fig. 13.3A), and also some of the experimental flow behavior for some yogurt systems flavored with cajeta (Fig.  13.3B) that were utilized to obtain their rheological properties.

13.5.3  Physicochemical and Flow Properties The physicochemical determinations were different for each dairy liquid. Beverage samples showed an acidity of 1.31–1.88 g/L, a range of 15.6–20.2°Bx as a function of added caramel, a pH of 6.36–6.52, and a density of 1048–1073 kg/m3, whereas yogurt systems exhibited an acidity of 4.50–6.30 g/L, a range of 7.30–20.4°Bx, and a pH of 4.45–4.95 as a function of the fermentation. It is clear that the physicochemical characteristics were influenced by the effect of two main process stages: the formulation and the fermentation. From the corresponding rheograms for the different studied milk beverages (Ramírez-Sucre and Vélez-Ruiz, 2011) and yogurt systems (Ramírez-Sucre and Vélez-Ruiz, 2013), the corresponding flow properties were obtained, they are summarized next. In all, 15 fresh milk beverages flavored with cajeta showed a range of 0.61–0.98 for the flow behavior index (n), expressing an NNF behavior, a range of 3.7–99 mPa sn for the consistency coefficient, which are low values due to the liquid nature, and a range of 0–329 mPa for the yield stress, indicating that some of the beverages did not have plasticity, properly. These flow properties are a function of the studied

448  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

variables: three fat contents, three gum concentrations, and three cajeta levels, given a total of 27 systems that were reduced to only 15 by following a Box-Behnken experimental design. Similarly, the flow characterization of the 18 fresh yogurt systems also prepared with cajeta exhibited a range of 0.61–1.07 for the flow behavior index (n), expressing a NNF behavior and three of them ­expressed a NF nature, a range of 3.02–99.9 mPa sn for the consistency coefficient, which are low values due to the drinkable nature of the yogurt, and a range of 0.02–372.7 mPa for the yield stress, indicating that some of the systems have a very low plastic response. These flow properties are very similar to those of the milk beverage, and also a function of the studied variables: three fat contents, two gum concentrations, and three cajeta levels, given a total of 27 systems that also were reduced to 15 by the same Box-Behnken design. The main difference between both dairy products was the fermentation process in the yogurt manufacturing.

13.6  Engineering Aspects 13.6.1  Transportation of NF Through Pipelines In order to apply the BE to compute and lately design some of the variables included in it, for food liquids such as clarified juices, honey, milk, oil, soft drinks, solutions and water, among others, a numerical example is developed. As is known, the balance of energy is carried out between two reference or selected locations or points, normally ­related with the entrance and the outlet of the transport system. In many cases, it may be more than one point to be selected, which may be meaning of more than one entrance or exit, although the most frequent application is with only two points, 1 and 2, as can be observed in Fig. 13.2. To compute any parameter of the BE, like pressure, average velocity, energy loss or power needed as the most important and common, other parameters like α (the kinetic correction factor), fD (the Darcy friction factor), and/or the equivalent length may be obtained from graphical or mathematical correlations; they are widely known as the Moody graph, which is the most famous graphical representation (Charm, 1971; Foust et  al., 1980; Ibarz and Barbosa, 1999; McCabe et al., 2001; Geankoplis, 2006; Vélez-Ruiz, 2017a).

13.6.2  Example for NF Thus, as a first example of a food transport system to apply the BE model, a procedure identified as the equivalent-length method will be followed (Hooper, 1981; Vélez-Ruiz, 2017a). For the procedure, additional data should be known, considering that the fluid in the transport system is raw milk. It may be supplied at a rate of 10,800 kg/h

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   449

at a pressure of 3 atm, and also knowing that the filter as the process equipment has a pressure drop of 123 kPa, in which the pumping requirement should be calculated. The fluid is transported or moved by a stainless steel pipeline from the supply tank (1) by a centrifugal pump and delivered at the outlet; (2) the transport system includes three diameters (1.0, 2.5, and 2 in.) for sections of 30 m each, in which three 90 degree elbows (long radius, standard, and street) are in the first section; one gate valve (one-half open) in the second; and one tee (flow through) in the third section, and the aforementioned process equipment (filter) is part of the system. The theoretical calculations to evaluate the pumping power required for this particular system is developed and specified below. Starting from the energy balance, the work for pumping will be computed by rearrangement of the terms:

ηWp = ( P2 − P1 ) / ρ + ( Z 2 − Z1 ) g / g c + (v22 / 2α g c − v12 / 2α g c ) + Ef

(13.2)

The difference in the pressure between points 2 and 1 or energy of pressure is P2 − P1 = ρ

 101, 300 Pa    1 atm  = 196.70 N ⋅ m kg kg 1030 3 m

( 3 atm − 1 atm ) 

(13.8)

The potential energy is:   9 m − 3 m )  9.81 2  ( Z 2 − Z1 ) g ( s   m

=

gc

kg ⋅ m 1 N ⋅ s2

= 58.86

N⋅m kg

(13.9)

For the kinetic energy the velocity of the fluid inside the tank is insignificant due to a big flow area, and thus the average velocity at point 2 must be obtained, with an internal diameter of 2.067 in. for 2″ in the exit tube. Then from the mass flow or continuity equation, 

 ω  ω = ρ V = ρ Av ∴v2 =    ρ A 2 kg   h   kg (13.10)   10 , 800   3 h   3600 s   s =1.345 m = = 2 s 0.0254 m   2.23 kg kg  π   1030 3  · 2.067 in.  m m 4 1 in.    

450  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

whereas for the lecture of α, the Reynolds number should be computed. m kg 1.345 ⋅1030 3 ⋅ 0.0525 m  vρD  s m Re2 =   = 3.0 mPa ⋅ s ( g c )  µ 2 kg 72.733 m ·s = 24 , 244 ( dimensionless ) = kg 0.003 m·s

(13.11)

The value for α = 0.91, and may be read from Foust et al. (1980). For practical purposes, the kinetic correction factor has been rounded to 0.5 for laminar flow and 1.0 for turbulent flow in which a small (but acceptable) error is involved. Therefore: 2

m  (v − v ) =  1.345 s  − 0 = 0.994 N ⋅ m kg ⋅ m 2α g c kg 2 ⋅ 0.91 ⋅1 N ⋅ s2 2 2

2 1

(13.12)

The friction energy (Ef ) as a parameter representing the loss of energy due to the frictional phenomenon is a term composed of several elements or components that correspond to the different sections of the food transport system: entrance (Fi), pipe (Ft), fittings (Ff ), diameter changes (Fr and Fe), and pressure drop in the equipment, a filter (Feq), in this example, E f = Fi + Ft + F f + Fe + Fr + Feq

(13.13)

(i) Entrance: Fi =

ki v 2 2α g c

(13.14a)

where ki has been computed for different entrance types, as 0.5 for sharp edged, 0.78 for protected, and 0.23 for rounded entrances (Appendix C-2c, Foust et al., 1980); it includes the average velocity in this section (vs1) not being the same as that of the previously computed one; then:

ωs1 = ( ρvA )s1 = ( ρvA )2

(13.14b)

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   451

where the fluid density is the same and the flow-sectional area is πD2/4, and taking the data for point 2 that are known, m  ( 2.067 in. ) ∴(vD ) = (vD ) ∴vs1 = 1.345  s1 2 s  (1.049 in. )2

2

2

2

 m  = 5.222  s 

(13.14c)

Consequently, the Res1 has another value v ρD = Re s1 = s1 µ

5.222

kg m kg ⋅1030 3 ⋅ 0.02665 m 143.34 s m m·s = 47780.43 , = kg 3.0 mPa ⋅ s ( g c ) 0.003 m·s

where α = 0.94 (from Fig. 13.2; Foust et al., 1980), which allows us to complete the calculation by substituting in Eq. (13.14a): 2

m  0.5  5.22  N⋅m s   Fi = = 7.25 kg ⋅ m kg 2 ⋅ 0.94 ⋅1 N ⋅ s2 (ii) Pipes with different diameter, in which the corresponding equation is Ft = f D

Lv 2 D 2α g c

(13.14d)

to apply at each section; thus, Ft should be considered for the three sections; Ft = Ft1 + Ft2 + Ft3, where fD is the Darcy friction factor, normally taken from the Moody graph (Appendix C-3, Foust et al., 1980) or evaluated by a proper correlation; L/D is identified as the equivalent length. The velocity of section 2 (s2) is unknown; it may be obtained by Eq. (13.10) or (13.14b), ∴(vD 2 ) = (vD 2 ) ∴vs 2 = 1.345 s2

2

m  ( 2.067 in. )  s  ( 2.469 in. )2

2

 m  = 0.943  s 

and Res2 has another value; then, v ρD = Re s 2 = s 2 µ

0.943

kg m kg ⋅1030 3 ⋅ 0.0627 m 60.90 m s m ⋅ s = 20299.96 , = kg 3.0 mPa ⋅ s ( g c ) 0.003 m ⋅s

where α = 0.92 (Fig. 13.2, Foust et al., 1980). With the Reynolds numbers (47,780.43, 20,299.96, and 24,244.46, respectively) and with the relative roughness (0.0017 for 1″, 0.00069

452  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

for 2.5″, and 0.00088 for 2″; Appendix C-1, Foust et al., 1980), the corresponding values for fD are: 0.025, 0.027, and 0.026 (Appendix C-3, Foust et al., 1980), being in these cases very similar. 2 2  m   m    5 222 . . 0 943         30 m 30 m s    s      Ft = 0.025 ⋅ + 0.027 ⋅  0.0266 m 2 ⋅ 0.94 ⋅1 kg ⋅ m   0.0627 m 2 ⋅ 0.92 ⋅1 kg ⋅ m  2    N ⋅s   N ⋅ s2   2  m   1.345     30 m N⋅m N⋅m s    +  0.026 ⋅ = ( 408.97 + 6.24 + 14.77 ) = 429.98  0.0525 m 2 ⋅ 0.91 ⋅1 kg ⋅ m  kg kg 2   N s ⋅  

(iii) For fittings, in which the loss is due to wall friction and turbulence, a friction coefficient (kf ) has been evaluated for common geometry fittings: Ff = K f

v2 2α g c

(13.14e)

That will not be applied in this problem because there are differences between various references for the same fitting. In my experience, in the first one (Eq. 13.14d), the same relationship applied to pipes may be used as a function of the equivalent length, treating the fitting as a piece with an equivalent straight pipe. It allows a more accurate evaluation of the energy losses; some values of the equivalent length are presented in Table 13.3 (Appendix C-2a, Foust et al., 1980). Therefore, for the first section (with three 90 degree elbows of long radius, standard, and street types): 2  m     5.222   N⋅m s   F f 1 =  0.025 ⋅ ( 20 + 30 + 50 ) ⋅  = 36.26 kg ⋅ m   kg 2 ⋅ 0.94 ⋅1 2   N ⋅ s  

For the second section (with one-half open gate valve): 2  m     0.943   N⋅m s   F f 2 =  0.027 ⋅ (160 ) ⋅  = 2.09 kg ⋅ m   kg 2 ⋅ 0.92 ⋅1 2   N ⋅ s  

For the third section, in which in addition to the tee (flow through), there is a globe valve controlling the flow rate in the outlet:

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   453

Table 13.3  Equivalent Length in Pipe Diameters (L/D) for Some Fittings Fitting

Description

L/D

Fitting

Description

L/D

90 degrees elbow 90 degrees elbow Tee with flow Angle valve

Standard type Street type Through run Stem 45 degrees, fully open

30 50 20 145

90 degrees elbow 90 degrees elbow Tee with flow Angle valve

20 57 20 145

Check valve

Conventional swing

135

Check valve

Long radius Square corner Through branch Stem 45 degrees, fully open Clearway swing

Gate valve Gate valve Gate valve Gate valve Globe valve Globe valve

Conventional wedge disk, double disk or plug disk, fully open Conventional wedge disk, double disk or plug disk, three-quarters open Conventional wedge disk, double disk or plug disk, one half open Conventional wedge disk, double disk or plug disk, one-quarter open Conventional with no obstruction in flat, or plug type seat, fully open Conventional with wing or pin-guided disk, fully open

2  m   . 1 345     N⋅m s   F f 3 =  0.026 ⋅ ( 20 + 450 ) ⋅  = 12.15 kg ⋅ m   kg 2 ⋅ 0.91 ⋅1 2   N s ⋅  

The sum of the energy loss due to fittings at the pipeline is 36.26 + 2.09 + 12.15 = 50.5 N m/kg. (iv) To consider the changes of diameter, from 1 to 2.5″ as an enlargement (ke) and from 2.5 to 2.0″ as a sudden contraction (kr), the corresponding figures or equations may be utilized (Appendix C-2b, Foust et al., 1980): 2

m  5.222  2  v N⋅m s  Fe = K e s1 = 0.63 ⋅  = 9.14 kg ⋅ m 2α g c kg g 2 ⋅ 0.94 ⋅1 N ⋅ s2

(13.14f )

and 2

m   1.345  v N⋅m s  Fr = K r = 0.075 ⋅  = 0.08 kg ⋅ m 2α g c kg 2 ⋅ 0.91 ⋅1 N ⋅ s2 2 s3

(13.14g)

50 13 35 160 900 340 450

454  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

(v) And finally, to complete the Ef evaluation, the pressure drop through the process equipment (Feq) is considered as a function of the loss pressure recorded in the corresponding equipment by the pressure gauges at the entrance and outlet of the equipment: N 123, 000 2 N⋅m ∆P m Feq = = = 119.42 kg ρ kg 1030 3 m Now, summing all the computed magnitudes related with the loss of energy due to friction of the different elements for the descriptive food transport system: E f = ( 7.25 + 429.97 + 50.50 + 9.14 + 0.08 + 119.42 )

N⋅m N⋅m = 616.36 kg kg

Once all the energy terms have been considered, Eq. (13.2) may be utilized, in order to obtain the pumping work:

ηWp = (196.70 + 58.86 + 0.994 + 616.36 )

N⋅m N⋅m = 872.92 kg kg

From the computed values, it may be clearly observed that the main consumption of energy is due to the friction through the transport system, followed by the difference of pressure, the kinetic energy being of the lowest magnitude. In a physical sense, the BE is very illustrative; it allows us to visualize which one of the energy terms is the most significant. To complete the power evaluation, an additional calculation should be completed, on the basis of a mechanical efficiency for the pump of 60% as a practical situation (ηWp = 872.92 N m/kg): N⋅m N⋅m kg = 1454.87 kg 0.60

872.92 Wp =

and from it, the power is Pp = Wp · ω (Eq. 13.3) P = 1454.87

N ⋅ m kg  1 hp  ⋅3   = 5.85 hp kg s  745.7 W 

Then, a centrifugal pump of 6 hp, or less if the mechanical efficiency of the pump is higher, will be necessary to carry out the milk pumping from the tank or point 1 to the outlet or point 2. This computing procedure or methodology may be applied for evaluation of the pumping needs or another energy term or parameter from it, such as

Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)   455

height Z, pressure P, tube diameter D, or velocity v, for food transport systems with basic support of the BE model, that also is the fundamental mechanical energetic model for NNF.

13.6.3  Frictional Aspects Related With NNF With respect to the movement and transportation of foods as NNF, there is very little information and although there exist several advances in the study and modeling of this unit operation, most of the few studies done on NNF foods have been completed and favored by the advances on the flow behavior determinations of a diversity of foods. Flow behavior characterization is narrowly related to advances in rheometer design; therefore, there are a very good number of studies that have characterized the flow response of many liquid foods and just to mention related studies, some of them can be cited. Dairy products, such as yogurt, custard, and lactic beverages, have been rheologically characterized to know the influence of the formulation or the addition of bioactive compounds to improve their functionality. Díaz-Jimenez et al. (2004) analyzed the effect of fiber addition (3%–9% w/v) and fat decrease (three concentrations) on the physicochemical properties of settled and stirred yogurt. However, the same research group studied the effect of fiber (two wheat-bran sources at three levels) and calcium fortification (50 and 100 mg) on the rheological and physicochemical behavior of a semi-stirred yogurt (AportelaPalacios et al., 2005) and low-fat stirred yogurt fortified with calcium and fiber (Vélez-Ruiz et al., 2012). Custard was also studied to know the influence of the ingredients on the static and dynamic rheological properties of the formulations (Vélez-Ruiz et al., 2005; Tárrega et al., 2005) including their microstructural characteristics (Vélez-Ruiz et al., 2006). Yogurt, custard, and an acid beverage affected by caramel jam (Mexican cajeta) as an added important flavor, were also studied by Ramírez-Sucre and Vélez-Ruiz (2011, 2013, 2014), while Tárrega et al. (2012) added cocoa as a flavor source to dairy systems. Yogurt has been also enriched with omega-3 fatty acids, modifying the flow response of the dairy product (Macedo-y-Ramírez and Vélez-Ruiz, 2015), the flow properties being the most important part of these studies. Regarding the flow of foods and their frictional aspects, there are not too much works on NNF; there exist a good number of them on inorganic material, studying and calculating pressure drops and friction coefficients as a function of flow properties, flow regime, and/or other parameters, but unfortunately there are very few studies on biological fluids, particularly food fluids. Therefore, some few works done on food fluids and other related NNF that are taken as model ones, one of the more utilized being the CMC (carboxymethyl cellulose) solutions, can be cited.

456  Chapter 13  PUMPING NEEDS FOR TWO DAIRY PRODUCTS (FLAVORED MILK AND YOGURT)

The Moody graph, as a classical representation for the Darcy or Fanning frictional factor as a function of Reynolds number (Re) and the relative roughness (ε/D), was published in 1944 with a lot of information for NF (Charm, 1971; Welty et al., 1976; Foust et al., 1980; Ibarz and Barbosa, 1999; McCabe et al., 2001; Geankoplis, 2006; Vélez-Ruiz, 2017a). An equivalent graphic expression was developed by Dodge and Meztner in 1959 (Heldman and Singh, 1981; Rao and Anantheswaran, 1982; Valentas et al., 1997; Ibarz and Barbosa, 1999; Vélez-Ruiz, 2017a) including very few data for pseudoplastic and dilatant NNF (power law fluids), in which the Fanning friction factor is a function of the GRe and the flow behavior index (n). Two and a half decades later, in 1986 a poor figure for plastic fluids (BP fluids) was developed, where the Fanning friction factor is a function of GRe and the Hedstrom number (He). More recently, many experiments were carried out by García and Steffe (1986a,b) for plastics fluid or HB fluids, in which the Fanning friction factor is a function of GRe and generalized Hedstrom numbers (GHe), representing the friction factor for different flow behavior indexes in a range of 0.2–1.0 (Ibarz et al., 1994; Valentas et al., 1997; Ibarz and Barbosa, 1999; Vélez-Ruiz, 2017a). All the graphic representations result in great utility for fast calculations. Nakayama et al. (1980) developed a pioneer work in which an NNF of plastic nature (fish paste with τ0 ~ 2000 Pa and n = 0.9) was forced through a pipeline where shear stresses in a range of 2100–2900 Pa and shear rates in a range of 20–240 s−1 were utilized. Steffe et al. (1984) completed an excellent research study, in which the pressure drops across valves and fittings for pseudoplastic applesauce fluids in laminar flow were completed, obtaining the corresponding correlations for K fittings (elbow, tee, and three-way plug valve) as a function of the GRe that are presented in the following. K elbow = 191(GRe )

−0.896

K valve = 30.3 (GRe )

−0.492

, K tee = 29.4 (GRe )

−0.504

,

(13.15)

García and Steffe (1986a,b) compared the computed magnitudes for the friction factor of HB plastic fluids as a function of the flow behavior index, generalized Reynolds, and Hedstrom numbers, and they found significant differences in which the flow properties (n and τ0) were highly important. Bradford et al. (1994) completed an experimental work, combining tests at the laboratory and also in industry, to evaluate the pressure loss expressed by k values in molasses from the cane industry, as a function of the GRe. They found that those values computed from experimental data at low Reynolds numbers (8.25% and fat levels to satisfy nonfat yogurt (3.25%) before the addition of other ingredients like sugars, aroma, and flavorings and the pH varies from 4.0 to 4.5 (Chandan, 2006). In this category a long list of commercial fermented diary beverages such as Actimel, Acidophilus sour milk, yakult, Yakult Miru-Miru, and the rest illustrated in Table 14.3 are included.

14.3.1.2  Mixed Lactic Acid and Alcoholic Fermented Dairy-Based Probiotic Beverages Kumis Kumis, also known as koumiss, the ancient beverage which Scythian tribes (Central Asia Steppes) used to drink some 25 centuries ago is an alcoholic beverage made from fermented mare's milk. Mare's milk is usually not consumed raw, because it tends to have a strong laxative effect, although this effect is sometimes used medically. Instead, mare's milk is almost always fermented into kumis. Mare’s milk is characterized by high water and low-calorie content, total solids content (10.5%), significantly less amount of proteins (1.93%–2.1%), fat (1.25%–1.3%), and significantly higher amounts of lactose (6.4%–6.91%) compared to cow milk total solids content (12.6%), protein (3.43%), fat (3.61%). Mare’s milk has a composition similar to human milk and is well digested, so it is a perfect alternative to cow’s milk for feeding children who are allergic to cow’s milk (Oftadel et  al., 1983; Nikkhah, 2012; Salimei and Fantuz, 2012; Gemechu et al., 2015). It is made by fermenting mare's milk while stirring or churning. It is a dairy product involving lactic acid and alcoholic fermentation, which implies that during the fermentation, Lactobacillus bulgaricus acidifies the milk, and Saccharomyces lactis turns it into a carbonated and mildly alcoholic drink. Ishii et al. (2014) identified a total of 14 species belonging to 4 genera of LAB (Lactobacillus acidphilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus paracasei subsp. Paracasei, Lactobacillus paracasei subsp. tolerans, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus lactis subsp. cremoris, Lactobacillus brevis, Lactobacillus helveticus, Lactococcus lactis subsp. lactis, Streptococcus salivarius subsp. thermophilus, Pediococcus acidilactis, Leuconostoc oenosand) and 11 species of yeasts belonging to 5 genera (Kluyveromyces marxianus var. marxianus, Kluyveromyces marxianus var. lactis, Kluyveromyces

Chapter 14  DAIRY AND NONDAIRY-BASED BEVERAGES   495

mesenteroides, Saccharomyces cerevisiae, Saccharomyces florentinus, Saccharomyces fragilis, Debaryomyces polymorphus, Debaryomyces hansenii, Candida kefyr, Candida tropicalis, Torula delbrueckii) from Mongolian koumiss. However, the type and the number of microbes implicated in the product differ greatly from country to country and from author to author. Chaves-López et al. (2011) reported alternative Colombian kumis as a fermented cow milk, widely consumed in rural and urban areas in South West Colombia. The end product of this fermentation is a low alcoholic (1%–2%), creamy, and sparkling beverage, with a slight degree of sourness. The same author confirmed the presence of yeast, mesophilic LAB, enterococci, in all 13 traditional Colombian kumis samples included in the study whereas Enterobacteriaceae are present in only 4 out of 13 studied samples. Kefir Actually, Kefir is elaborated in different countries and can be made from diverse mammalian milk including cow, goat, sheep, camel, buffalo, and other milk substitutes such as soy milk, rice milk, and coconut milk (Irigoyen et al., 2005). Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. Different methods are applied to obtain the viscous and self-carbonated beverage with a smooth, slightly foamy body and whitish color product (Yuksekdag et al., 2004). The traditional as well as the commercial Kefir is produced with Kefir grains. This grain is a kind of yogurt starter, white to yellow-white in color, gelatinous, of variable size (0.3–3.5 cm in diameter), and comprises a microbial symbiotic mixture of LAB (108 CFU g−1), yeast (106–107 CFU g−1), and acetic acid bacteria (105 CFU g−1) that stick to a polysaccharide matrix called kefiran (Granato et al., 2010a, b; Chen et al., 2015). In the traditional method, kefir grains are directly added to the pasteurized and cooled milk and fermented for a period between 18 and 24 h at 20–25°C with stirring. At the end of the fermentation the grains are sieved in a sterile sieve, which can be reused for a new fermentation, while the kefir beverage is stored at 4°C, ready for consumption (Beshkova et al., 2002). In the industrial (commercial) process the sterile milk is inoculated with lyophilized starter cultures containing LAB and yeast of kefir (Prado et  al., 2015) or the direct-to-vat inoculation and direct-to-vat set kefir starter cultures are also the possible procedures. The microbial composition may vary from country to country, among different kefir products, according to kefir origin, the substrate used in the fermentation process, and the culture maintenance methods. Garrote et al. (2001) reported that Kefir grains and beverage from Argentina contains Lactobacillus kefir, Lactobacillus kefiranofaciens,

496  Chapter 14  DAIRY AND NONDAIRY-BASED BEVERAGES

L. paracasei, Lactobacillus plantarum, Lactococcus lactis ssp. lactis, Kluyveromyces marxianus, Lactobacillus parakefir, Saccharomyces cerevisiae, Saccharomyces unisporus, Leuconostoc mesenteroides, Acetobacter sp., Saccharomyces sp., Lactococcus lactis ssp. lactis biovar diacetylactis, Lactococcus lactis, Lactobacillus kefiri, and Lactobacillus parakefiri (Prado et  al., 2015), meanwhile Kefir beverage from China contains Acetobacter acetic, E. faecalis, Enterococcus durans, Lactococcus lactis ssp. cremoris, Leuconostoc pseudomesenteroides, Leuconostoc paramesenteroides, Lactobacillus brevis, Lactobacillus acidophilus, Saccharomyces sp., Brettanomyces sp., Candida sp., Saccharomycodes sp., and Acetobacter rancens (Prado et  al., 2015; Yang et al., 2007).

14.3.2  Cheese Whey-Based Probiotic Beverages Cheese whey is a green-yellowish milk serum, the liquid portion of milk left after the formation of curd (Siso, 1996) during conventional cheesemaking or casein manufacture. In the past whey was considered to be an onerous by-product and was either used as an animal feed or was disposed of as waste (was spread on the fields or dumped in the rivers). Whey is a serious pollutant as it imposes a very high biochemical oxygen demand (BOD) of 30,000–50,000 ppm and chemical oxygen demand (COD) of 60,000–80,000 ppm (Macwan et al., 2016). Actually, it is considered as a coproduct of cheese-making and casein manufacture industries where its components are fractionated with different technologies (drying, membrane) to lactose, minerals, and soluble proteins to be used as ingredients in food and pharmaceutical industries. Milk whey represents approximately 85%–90% of the total milk volume and retains about 45%–55% of milk nutrients with 8%–10% of dried extract. From nutritional view point, the average composition of whey is water (93%), lactose (4.5%–5.0% w/v), soluble proteins (0.6%–0.85% w/v), minerals (0.53%), a minimum amount (0.36%) of fat (Kosikowski, 1979; Pescuma et  al., 2010), and higher amounts of vitamin B2 (responsible for the yellowish color) compared to fresh milk (Božanić et al., 2014). The composition depends on several factors, including the type of cheese and the processing method, the method used for casein precipitation, milk thermal treatment among others (Johansen et al., 2002; Lucas et  al., 2006). Whey proteins are also known as soluble proteins, a complete protein pack, having an exceptional biological value that exceeds that of egg protein (standard protein for biological valor determination) by about 15% manly due to the high content of branched-chain essential amino acids (>20%, w/w) (isoleucine, leucine, and valine) which gives a wide ranging functional attributes (such as good solubility, viscosity, gelling, and emulsifying p ­ roperties, and

Chapter 14  DAIRY AND NONDAIRY-BASED BEVERAGES   497

their concentrates are widely used in the food industry) for nutritional, biological, and food purposes (Smithers, 2008). The whey proteins are composed of thermosensitive fractions, such as 65% of β-lactoglobulin (β-Lg), 25% of α-lactalbumin (α-La), 8% of blood serum albumin and immunoglobulin as well as thermos-stable proteose-peptone. Since whey proteins are easier to digest than casein, they are used for purposes such as the manufacture of infant formulas or to increase the nutritional value of dairy and other food products. Based on the casein coagulation method there are two types of whey: acidic and sweet. In acidic whey, the coagulation of casein is ­obtained principally by acidification, which is characterized by lowering of pH to about 3.6–5.1 (acid action) and the sweet whey has a pH of 5.8–6.6 (enzyme action), lactose of 4.6%–5.2%, and total solids content of 6.3%–7% (Konrad et al., 2012). Ample beverages, both alcoholic (whey beer, whey wines) and nonalcoholic, can be manufactured from whey. Whey-based beverages constitute an emerging segment of non-conventional dairy products. The availability of essential nutrients mainly lactose and proteins for the growth of microorganisms make the whey one of the potential substrate to produce different whey-based probiotic beverages. The fermentation of whey by LAB allows the production of beverages with significantly improved characteristics (Dalev et  al., 2006). However, a problem associated with whey-based probiotic beverages is the low total solids content of whey, a relatively high lactose to glucose ratio and excessive acidity, which renders fermented beverage watery and an unappealing taste. In order to correct these difficult challenges, the total solids content is increased and the sour taste and aroma are improved by adding sucrose and fruit juice and submitted for lactic acid fermentation. Fermentation is one of the oldest forms of food preservation and biological upgrading of dairy by-product into value-added food has been well established. In the past different whey-based beverages are proposed, the ready-to-serve-type beverage prepared by mixing an appropriate fruit juice or concentrate and minimally processed whey along with other minor additives and thermally processed to make it shelf stable (e.g., concentrated fruit-based whey beverages, whey protein-­ enriched whey beverages, whey-based sports and thirst-quenching beverages, fermented beverages from whey) (Pescuma et  al., 2010; Vandna and Hati, 2015). The impediment of probiotic fruit juices to maintain the viability of probiotic microbe is the detrimental effects of the low pH environment (