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Nano- and Microencapsulation for Foods

Nano- andMicroencapsulationfor Foods

Edited by

Hae-Soo Kwak

Sejong University, South Korea

This edition first published 2014 © 2014 by John Wiley & Sons, Ltd

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Library of Congress Cataloging-in-Publication Data

Nano- and microencapsulation for foods / edited by Hae-Soo Kwak.pages cm

Includes bibliographical references and index.ISBN 978-1-118-29233-4 (cloth)

1. Food addititives. 2. Microencapsulation. 3. Functional foods. 4. Controlled release preparations.I. Kwak, Hae-Soo, editor of compilation.

TX553.A3N254 2014641.3’08–dc23

2013045013

A catalogue record for this book is available from the British Library.

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Contents

List of Contributors xiii

Preface xvii

1 Overview of Nano- and Microencapsulation for Foods 1Hae-Soo Kwak

1.1 Introduction 11.2 Nano- or microencapsulation as a rich source of delivery of functional components 31.3 Wall materials used for encapsulation 31.4 Techniques used for the production of nano- or microencapsulation of foods 41.5 Characterization of nano- or microencapsulated functional particles 51.6 Fortification of foods through nano- or microcapsules 61.7 Nano- or microencapsulation technologies: industrial perspectives and applications in

the food market 61.8 Overview of the book 8

Acknowledgments 12References 12

Part I Concepts and rationales of nano- and microencapsulationfor foods 15

2 Theories and Concepts of Nano Materials, Nano- and microencapsulation 17Jingyuan Wen, Guanyu Chen, and Raid G. Alany

2.1 Introduction 172.2 Materials used for nanoparticles, nano- and microencapsulation 19

2.2.1 Polymers 192.3 Nano- and microencapsulation techniques 20

2.3.1 Chemical methods 202.3.2 Physico-chemical methods 232.3.3 Other methods 252.3.4 Factors influencing optimization 28

2.4 Pharmaceutical and nutraceutical applications 302.4.1 Various delivery routes for nano- and microencapsulation systems 30

vi CONTENTS

2.5 Food ingredients and nutraceutical applications 352.5.1 Background and definitions 352.5.2 Nanomaterials, nano- and microencapsulation in nutraceuticals 36

2.6 Conclusion 37References 38

3 Rationales of Nano- and Microencapsulation for Food Ingredients 43Sundaram Gunasekaran and Sanghoon Ko

3.1 Introduction 433.2 Factors affecting the quality loss of food ingredients 45

3.2.1 Oxygen 453.2.2 Light 473.2.3 Temperature 483.2.4 Adverse interaction 493.2.5 Taste masking 50

3.3 Case studies of food ingredient protection through nano- and microencapsulation 503.3.1 Vitamins 513.3.2 Enzymes 523.3.3 Minerals 533.3.4 Phytochemicals 543.3.5 Lipids 553.3.6 Probiotics 553.3.7 Flavors 56


4 Methodologies Used for the Characterization of Nano- and Microcapsules 65Minh-Hiep Nguyen, Nurul Fadhilah Kamalul Aripin, Xi G. Chen, and Hyun-Jin Park

4.1 Introduction 654.2 Methodologies used for the characterization of nano- and microcapsules 67

4.2.1 Particle size and particle size distribution 674.2.2 Zeta potential measurement 754.2.3 Morphology 774.2.4 Membrane flexibility 804.2.5 Stability 824.2.6 Encapsulation efficiency 83

4.3 Conclusion 88Acknowledgements 88References 88

5 Advanced Approaches of Nano- and Microencapsulation for Food Ingredients 95Mi-Jung Choi and Hae-Soo Kwak

5.1 Introduction 955.2 Nanoencapsulation based on the microencapsulation technology 965.3 Classification of the encapsulation system 97

5.3.1 Nanoparticle or microparticle 975.3.2 Structural encapsulation systems 100

5.4 Preparation methods for the encapsulation system 1065.4.1 Emulsification 106

CONTENTS vii

5.4.2 Precipitation 1075.4.3 Desolvation 1085.4.4 Ionic gelation 109

5.5 Application of the encapsulation system in food ingredients 1095.6 Conclusion 110

References 111

Part II Nano- and microencapsulations of food ingredients 117

6 Nano- and Microencapsulation of Phytochemicals 119Sung Je Lee and Marie Wong

6.1 Introduction 1196.2 Classification of phytochemicals 120

6.2.1 Flavonoids 1206.2.2 Carotenoids 1246.2.3 Betalains 1266.2.4 Phytosterols 1276.2.5 Organosulfurs and glucosinolates 128

6.3 Stability and solubility of phytochemicals 1296.4 Microencapsulation of phytochemicals 130

6.4.1 Spray-drying 1316.4.2 Freeze-drying 1356.4.3 Liposomes 1366.4.4 Coacervation 1386.4.5 Molecular inclusion complexes 141

6.5 Nanoencapsulation 1466.5.1 Nanoemulsions 1476.5.2 Nanoparticles 1486.5.3 Solid lipid nanoparticles (SLN) 1506.5.4 Nanoparticles through supercritical anti-solvent precipitation 152


7 Microencapsulation for Gastrointestinal Delivery of Probiotic Bacteria 167Kasipathy Kailasapathy

7.1 Introduction 1677.2 The gastrointestinal (GI) tract 169

7.2.1 Microbiota of the adult GI tract 1697.2.2 Characteristics of the GI tract for probiotic delivery 170

7.3 Encapsulation technologies for probiotics 1737.4 Techniques for probiotic encapsulation 175

7.4.1 Microencapsulation (ME) in gel particles using polymers 1757.4.2 The extrusion technique 1757.4.3 The emulsion technique 1777.4.4 Spray-drying, spray-coating and spray-chilling technologies 1797.4.5 Microencapsulation technologies for nutraceuticals incorporating probiotics 182

7.5 Controlled release of probiotic bacteria 1827.6 Potential applications of encapsulated probiotics 183

7.6.1 Yoghurt 1847.6.2 Cheese 185

viii CONTENTS

7.6.3 Frozen desserts 1867.6.4 Unfermented milks 1867.6.5 Powdered formulations 1877.6.6 Meat products 1877.6.7 Plant-based (vegetarian) probiotic products 188

7.7 Future trends and marketing perspectives 189References 191

8 Nano-Structured Minerals and Trace Elements for Food and NutritionApplications 199Florentine M. Hilty and Michael B. Zimmermann

8.1 Introduction 1998.2 Special characteristics of nanoparticles 2008.3 Nano-structured entities in natural foods 2028.4 Nano-structured minerals in nutritional applications 202

8.4.1 Iron 2028.4.2 Zinc 2078.4.3 Calcium 2098.4.4 Magnesium 2108.4.5 Selenium 2118.4.6 Copper 211

8.5 Uptake of nano-structured minerals 2128.6 Conclusion 213

References 214

9 Nano- and Microencapsulation of Vitamins 223Ashok R. Patel and Bhesh Bhandari

9.1 Introduction 2239.2 Vitamins for food and nutraceutical applications 224

9.2.1 Vitamins: nutritional requirement and biological functions 2249.2.2 Vitamins: formulation challenges and stability issues 224

9.3 Colloidal encapsulation (nano and micro) in foods: principles of use 2279.3.1 Solid-in-liquid dispersions 2299.3.2 Liquid-in-liquid dispersions 2329.3.3 Dispersions of self-assembled colloids 2349.3.4 Encapsulation in dry matrices 2389.3.5 Molecular encapsulation of vitamins in cyclodextrins 239

9.4 Conclusion and future trends 240References 241

10 Nano- and Microencapsulation of Flavor in Food Systems 249Kyuya Nakagawa

10.1 Introduction 24910.2 Flavor stabilization in food nano- and microstructures 250

10.2.1 Application of encapsulated flavors 25010.2.2 Interactions between flavor compounds and carrier matrices 25110.2.3 Flavor retention in colloidal systems 25110.2.4 Flavor retention in food gel 25210.2.5 Flavor inclusion in starch nanostructure 253

CONTENTS ix

10.3 Flavor retention and release in an encapsulated system 25410.3.1 Mass transfer at the liquid–gas interface 25410.3.2 Mass transfer at a solid–gas interface 258

10.4 Nano- and microstructure processing 25910.4.1 Spray-drying 26010.4.2 Freeze-drying 26210.4.3 Complex coacervation 264

10.5 Conclusion 266Acknowledgements 267References 267

11 Application of Nanomaterials, Nano- and Microencapsulation to Milk andDairy Products 273Hae-Soo Kwak, Mohammad Al Mijan, and Palanivel Ganesan

11.1 Introduction 27311.2 Milk 274

11.2.1 Microencapsulation of functional ingredients 27411.2.2 Microencapsulation of vitamins 27811.2.3 Microencapsulation of iron 27911.2.4 Microencapsulation of lactase 28111.2.5 Nanofunctional ingredients 28511.2.6 Nanocalcium 287

11.3 Yogurt 28711.3.1 Microencapsulation of functional ingredients 28711.3.2 Microencapsulation of iron 28811.3.3 Nanofunctional ingredients 289

11.4 Cheese 29111.4.1 Microencapsulation for accelerated cheese ripening 29111.4.2 Microencapsulation of iron 29211.4.3 Nanopowdered functional ingredients 292

11.5 Others 29311.5.1 Microencapsulation of iron 293


12 Application of Nano- and Microencapsulated Materials to Food Packaging 301Loong-Tak Lim

12.1 Introduction 30112.2 Nanocomposite technologies 302

12.2.1 Layered silicate nanocomposites 30212.2.2 Mineral oxide and organic nanocrystal composites 30512.2.3 Material properties’ enhancement of biodegradable/compostable polymers 306

12.3 Intelligent and active packaging based on nano- and microencapsulation technologies 30712.3.1 Product quality and shelf-life indicators 30812.3.2 Nano- and microencapsulated antimicrobial composites 31212.3.3 TiO2 ethylene scavenger for shelf-life extension of fruits and vegetables 317


x CONTENTS

Part III Bioactivity, toxicity, and regulation of nanomaterial,nano- and microencapsulated ingredients 325

13 Controlled Release of Food Ingredients 327Sanghoon Ko and Sundaram Gunasekaran

13.1 Introduction 32713.2 Fracturation 32813.3 Diffusion 32913.4 Dissolution 33113.5 Biodegradation 33313.6 External and internal triggering 334

13.6.1 Thermosensitive 33513.6.2 Acoustic sensitive 33613.6.3 Light-sensitive 33713.6.4 pH-sensitive 33813.6.5 Chemical-sensitive 33913.6.6 Enzyme-sensitive 33913.6.7 Other stimuli 340


14 Bioavailability and Bioactivity of Nanomaterial, Nano- andMicroencapsulated Ingredients in Foods 345Soo-Jin Choi

14.1 Introduction 34514.2 Bioavailability of nano- and microencapsulated phytochemicals 34714.3 Bioavailability of other nano- and microencapsulated nutraceuticals 35214.4 Bioavailability of nano- and microencapsulated bioactive components 35514.5 Conclusion 357

References 358

15 Potential Toxicity of Food Ingredients Loaded in Nano- and Microparticles 363Guanyu Chen, Soon-Mi Shim, and Jingyuan Wen

15.1 Introduction 36315.2 Factors influence the toxicity of nano- and microparticles 365

15.2.1 Size of the nano- and microparticles 36615.2.2 Shape of the nano- and microparticles 36715.2.3 Solubility of the nano- and microparticles 36715.2.4 Chemical composition of the nano- and microparticles 367

15.3 Behavior and health risk of nano- and microparticles in the gastrointestinal (GI) tract 37015.3.1 Absorption 37015.3.2 Distribution 37115.3.3 Excretion/elimination 371

15.4 Toxicity studies of nano- and microparticles 37115.4.1 Oral exposure studies for toxicity 37115.4.2 In vitro studies for toxicity 37215.4.3 Lack of an analytical method model to evaluate the safety of micro- and

nanoparticles 373

CONTENTS xi

15.5 Risk assessment of micro- and nanomaterials in food applications 37415.5.1 Risk assessment 375


16 Current Regulation of Nanomaterials Used as Food Ingredients 383Hyun-Kyung Kim, Jong-Gu Lee, and Si-Young Lee

16.1 Introduction 38316.2 The European Union (EU) 384

16.2.1 Definition 38416.2.2 The EFSA Guidance 38516.2.3 Regulation 386

16.3 The United Kingdom (UK) 38816.4 France 38916.5 The United States of America (USA) 38916.6 Canada 39116.7 Korea 39216.8 Australia and New Zealand 393

References 393

Index 395

List of Contributors

Raid G. AlanyDepartment of Pharmaceutical Science, The School of Pharmacy, University of

Auckland, Auckland, New Zealand

Nurul Fadhilah Kamalul AripinDepartment of Biotechnology, School of Life Sciences and Biotechnology, Korea

University, Seoul, South Korea

Bhesh BhandariFood Processing Technology and Engineering, School of Agriculture and Food

Sciences, The University of Queensland, Brisbane, Australia

Guanyu ChenThe School of Pharmacy, Faculty of Medical and Health Sciences, University of


Xi G. ChenCollege of Marine Life Science, Ocean University of China, Qingdao, People’s Republic

of China

Mi-Jung ChoiDepartment of Bioresources and Food Science, College of Life and Environmental Sci-

ence, Konkuk University, Seoul, South Korea

Soo-Jin ChoiDepartment of Food Science and Technology, Sejong Women’s University, Seoul,

South Korea

Palanivel GanesanDepartment of Food Technology, Universiti putra Malaysia, Serdang, Malaysia

Sundaram GunasekaranDepartment of Biological Systems Engineering and Food Science, University of

Wisconsin-Madison, Madison, WI, USA

xiv LIST OF CONTRIBUTORS

Florentine M. HiltyLaboratory for Human Nutrition, Swiss Federal Institute of Technology Zurich, Zurich,

Switzerland

Kasipathy KailasapathySchool of Science and Health, University of Western Sydney, NSW, Australia and

School of Biosciences, Taylor’s University, Subang Jaya, Malaysia

Hyun-Kyung KimKorea Ministry of Food and Drug Administration, Chungcheongbuk-do, South Korea

Sanghoon KoDepartment of Food Science and Technology, Sejong University, Seoul, South Korea

Hae-Soo KwakDepartment of Food Science and Technology, Sejong University, Seoul, South Korea

Jong-Gu LeeKorea Ministry of Food and Drug Administration, Chungcheongbuk-do, South Korea

Si-Young LeeKorea Ministry of Food and Drug Administration, Chungcheongbuk-do, South Korea

Sung Je LeeInstitute of Food, Nutrition and Human Health, Massey University, Auckland,

New Zealand

Loong-Tak LimDepartment of Food Science, University of Guelph, Ontario, Canada

Mohammad Al MijanDepartment of Food Science and Technology, Sejong University, Seoul, South Korea

Kyuya NakagawaDivision of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto

University, Kyoto, Japan

Minh-Hiep NguyenDepartment of Biotechnology, School of Life Sciences and Biotechnology, Korea


Hyun-Jin ParkDepartment of Biotechnology, School of Life Sciences and Biotechnology, Korea


LIST OF CONTRIBUTORS xv

Ashok R. PatelVandemoortele Centre, Laboratory of Food Technology and Engineering, Faculty of

Bioscience Engineering, Gent University Gent, Belgium

Soon-Mi ShimDepartment of Food Science and Technology, Sejong University, Seoul, South Korea

Jingyuan WenThe School of Pharmacy, Faculty of Medical and Health Sciences, University of


Marie WongInstitute of Food, Nutrition and Human Health, Massey University, Auckland,

New Zealand

Michael B. ZimmermannLaboratory for Human Nutrition, Swiss Federal Institute of Technology Zurich,

Zurich, Switzerland

Preface

Nano- or microencapsulation technology is a very innovative and emerging technologywhich will have a great impact on bioactive food product development in the comingyears. The technologies are already well known in the fields of medicinal, pharmaceu-tical, and cosmetic product development. For the last 30 years, food science text bookshave been written about chemistry or microbiology of food. Now nano and medical sci-ence are joining with food science to increase the nano food market value and open up anew focus on the delivery of functional ingredients with high activity. These functionalingredients provide additional benefit to the consumers, aged from infants to seniorcitizens, by providing healthy enhancement of bodily functions.

This book contributes important information to world food science by detailing whatnano- or microencapsulation of foods is, the bioactive ingredients of which contributesignificantly to human health. There has not been such a comprehensive book publishedon nano- or microencapsulation previously, and this text covers the whole principleof encapsulation, the technologies involved in encapsulation, the characterization ofencapsulation, the functional products containing vitamins, minerals, probiotics, and itsregulations for its development in the world.

This book will be of interest to students, academics, and scientists who are involvedin the development of functional food using encapsulation technologies. Nano- ormicroencapsulation of functional compounds provides an alternative technology inthe protection of these compounds and offers efficient delivery to the target site.Uniquely this book covers the encapsulated products from nano- to microsize withsignificant bioactive functions. Thus, this work will be an important reference book onmicroencapsulation and is intended to present up-to-date information on the state ofthe art as the contributors are world authorities in this field.

Only a few books discuss nano- or microencapsulation and deal with the production,characterization, and toxicity of capsules. However, most books deal with the fragmentinformation of encapsulation and none of them cover the micro- or nanoencapsulationfor foods. I hope that this book will be unique in offering in-depth knowledge of nano-or microencapsulation, particularly with a focus on foods.

It has been quite challenging to produce a book with the broad scope covering thescientists all over the world. A special thanks to the publisher for giving me the chanceto publish the work. My special thanks goes to Dr. Palanivel Ganesan, as well as thelab students involved in editing of this publication. Finally, I am deeply indebted to mywife and sons for their strong support in the completion of this work.

Hae-Soo KwakEditor

1Overview of Nano- andMicroencapsulation forFoodsHae-Soo KwakDepartment of Food Science and Technology, Sejong University, Seoul, South Korea

1.1 IntroductionNano- or microencapsulation technology is a rapidly expanding technology offeringnumerous beneficial applications in the food industries. Nano- or microencapsulationtechnology is the process by which core materials enriched with bioactive compoundsare packed within wall materials to form capsules. This method helps to protect manyfunctional core compounds, such as antioxidants, enzyme, polyphenol, and micronutri-ents, to deliver them to the controlled target site and to protect them from an adverseenvironment (Gouin, 2004; Lee et al., 2013). Based on the capsule size, the name andthe technology of the encapsulation are different: the capsules which range from 3 to800 μm in size are called microcapsules and the technology is called microencapsu-lation technology (Ahn et al., 2010). If the particle size ranges from 10 to 1,000 nm,these are called nanospheres and the technology involved to encapsulate the bioactivecompounds within the nano size range is termed nanoencapsulation technology (Lopezet al., 2006). Nanocapsules differ from nanospheres when the bioactive systems are dis-persed uniformly (Couvreur et al., 1995). The development of the nanotechnology onthe nanometer scale has led to the development of many technological, commercial,and scientific opportunities for the industry (Huang et al., 2010).

Application of nanotechnology in the food industry involves many characteristicchanges on the macroscale, such as texture, taste, and color, which have led to thedevelopment of many new products. This also improves many functions, such as oralbioavailability, water solubility, and the thermal stability of functional compounds(McClements et al., 2009). It is claimed that the functional compounds provide manyhealth benefits in the prevention and treatment of many diseases, and these compoundscan easily be seen on the market in various forms. However, the sustainability of the

Nano- and Microencapsulation for Foods, First Edition. Edited by Hae-Soo Kwak.© 2014 John Wiley & Sons, Ltd. Published 2014 by John Wiley & Sons, Ltd.

2 CH 1 OVERVIEW OF NANO- AND MICROENCAPSULATION FOR FOODSTa

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delivery of functional bioactive compounds to the target site is very low, particularlylipophilic compounds. Improving the availability of the functional compounds enhancesthe absorption of the functional compounds in the gastrointestinal tract, which is a crit-ical requirement. The development of nano- or microencapsulation technologies offerspossible solutions to improve the bioavailability of many functional compounds (Chauet al., 2007). The methods used to develop the encapsulation technologies, to enclosethe functional compound encapsulated along with its applications in food, and its reg-ulatory framework are described in various chapters in this volume.

1.2 Nano- or microencapsulation as a rich sourceof delivery of functional components

Nano- or microencapsulation techniques are one of the most interesting fields inthat they can act as a carriers or delivery systems for functional components, suchas antioxidants, flavor, and antimicrobial agents (Wissing et al., 2004; Sanguansri andAugustin, 2006; McClements et al., 2009; Weiss et al., 2008). The major functional com-pounds that often need to be incorporated in foods can be divided into four categories:(1) fatty acids (e.g., omega three fatty acids); (2) carotenoids (e.g., β-carotene);(3) antioxidants (e.g., tocopherol); and (4) phytosterols (e.g., stigmasterol). Table 1.1shows a list of functional compounds that have been encapsulated into nano- ormicroemulsion systems, their expected benefits, and their fields of application. Appli-cations of the nano- or microencapsulation technologies in the food industries aremainly based on the stability of the capsules. During various environmental conditions,such as chilling, freezing, and thermal processing, which commonly occur duringfood processing, the capsules are susceptible to instability. The properties of physicalstability are at different levels during the encapsulation process, such as stabilityrequired in the food ingredients or in the food matrix. Furthermore, stability also varieswith the type of food system in which it is incorporated (McClements et al., 2009).

1.3 Wall materials used for encapsulationNano- or microencapsulation techniques are mainly used in the delivery of functionalcompounds to the target sites and largely depend on the carrier wall materials used.The effectiveness of the functional compounds wholly depends on the preservation ofthe compounds (Chen et al., 2006). Microencapsulation greatly helps in the deliverywith a suitable wall material, however, reducing the particle size to the nanosize greatlyincreases the delivery properties due to the increase in surface area per unit volume(Shegokar and Muller, 2010). Based on solubility, the functional compounds usedfor encapsulation can be classified as either lipophilic or hydrophilic. Water-solublefunctional compounds which are insoluble in lipids or organic solvents are termedhydrophilic functional compounds. The hydrophilic functional compounds are listed aspolyphenols, ascorbic acids (Lakkis, 2007; Dube et al., 2010). Functional compoundswhich are insoluble in water and soluble in lipids and organic solvents are termedlipophilic which includes lycopene, and β-carotene (Zimet and Livney, 2009; Leonget al., 2011). In the polymeric matrix system, the solubility also determines the release

4 CH 1 OVERVIEW OF NANO- AND MICROENCAPSULATION FOR FOODS

rate of their functional compounds. A hydrophilic compound shows a faster releaserate and low permeability, which is absorbed by active transport. Lipophilic compoundsshow high permeability through the intestine and are absorbed by active transport,and facilitate diffusion with a lower release rate (Varma et al., 2004; Kuang et al.,2010). Various kinds of wall materials are used in the delivery of functional lipophilicor hydrophilic compounds for nano- or microencapsulation techniques. The polymers,such as albumin, globulin, maltodextrin, chitosan, ethylcellulose gelatin, starch, andchitosan are used in the delivery systems (Reis et al., 2006). Bioavailabilities offunctional compounds were greatly increased with the development of the nanocarriersystem, such as whey protein. Nanotechnology also greatly increases the delivery ofvitamins and minerals to the mucosal systems (Chen et al., 2006).

1.4 Techniques used for the production of nano- ormicroencapsulation of foods

Functional compounds and wall material properties, such as particle size, size distribu-tion, encapsulation efficiency, shape, and solubility, are altered by the techniques usedfor the encapsulation. Therefore, it is important to select the proper technique based onthe requirement of either nano- or microencapsulation. Nanoencapsulation techniquesare more complex than the microencapsulation process. Numerous techniques havebeen used in the preparation of the microencapsulation process (Figure 1.1). However,coacervation, nano-precipitation, inclusion complexation, and supercritical fluid

Phytochemicals

Phytochemicals

Probiotics

Flavors

Flavors

Vitamins

Vitamins

Enzymes

Enzymes

Lipids

Lipids

Microencapsulation

Nanoencapsulation

Encapsulation ofFoods

Figure 1.1 Schematic representation of encapsulation of foods.

1.5 CHARACTERIZATION OF NANO- OR MICROENCAPSULATED FUNCTIONAL PARTICLES 5

extraction techniques are considered the nanoencapsulation techniques which canproduce capsules in the nano range. The size reduction of the capsules is mostlyachieved by the emulsification and emulsification solvent evaporation which has noimpact on any other factor, such as pH and temperature. Coacervation, the supercriticalfluid technique, and the inclusion complexation also help size reduction; however, itlargely depends on other factors, such as pH and temperature. Coacervation and super-critical fluid extraction are used for encapsulation of both hydrophilic and lipophiliccompounds, whereas emulsification-solvent evaporation and inclusion complexationare largely used for the lipohilic compounds (Reis et al., 2006; Leong et al., 2009).The major problems of the micro- or nanocapsules are irreversible aggregations andleakage of functional compounds, and that it is necessary to dry the compounds forbetter stability of these compounds. Freeze-drying and spray-drying techniques are themost commonly used techniques for the stable release of functional compounds (Choiet al., 2004). Drying increases greater stability compared to the original suspension,and it can sustain the functional compounds for long storage periods (Guterres, 2009).

1.5 Characterization of nano- or microencapsulatedfunctional particles

Characterization of nano- or microcapsules is an important way to understand thefunctional aspects of the bioactive compounds. A number of techniques are involvedin the characterization of both kinds of capsules, such as high performance liquidchromatography (HPLC), field flow fractionation, laser diffraction, online photoncorrelation spectroscopy, mass spectrometry, scanning electron microscopy (SEM),transmission electron microscopy (TEM), etc. Every technique has its own advantagesand disadvantages in the characterization of the capsules. Laser techniques can be usedto measure the particle size and particle size distribution in a wide range from 0.02 μmto a few millimeters with rapid accuracy. A dynamic light scattering technique (DLS) isusually applied to measure the particle size of emulsions, micelles, polymers, proteins,nanoparticles, or colloids in the range from 5–1000 nm. Acoustic spectroscopy is ableto determine the particle size of nano- and microcapsules at high concentrations from1 to 50% (v/v) depending on the nature of the system, due to the use of sound waves,which interact with particles in a similar manner to light, but have the advantagethat they can travel through concentrated suspensions. Nuclear magnetic resonance(NMR) is a powerful and complex analytical tool that allows the study of compoundsin either a liquid or a solid state, and serves equally in quantitative as in structuralanalysis. Small-angle X-ray scattering (SAXS) is a technique for the study of structuralfeatures of colloidal size particles where the elastic scattering of X-rays in a samplethat has non-homogeneities in the nanometric range, is recorded at very low angles(typically 0.1–10∘). The morphology of both nano- or microcapsules is observed byvarious microscopy techniques which have various limitations on the size view, such asan optical microscope that has a resolution limit of about 100–200 nm, and TEM has aresolution limit of <1 nm to ∼100 nm. Thus, imaging techniques enable the various sizesof the nano- or microcapsules to be measured accurately. Detailed characterization ofnano- or microcapsules is listed in Chapter 4.


1.6 Fortification of foods through nano- ormicrocapsules

Nano- or microtech companies are trying to enhance their food products with nano-or microencapsulated nutrients; the taste and appearance are enhanced by thenano- or microencapsulated functional ingredients or by reducing the original nutrientcontent of fat or sugar and by improving the mouth feel of the product. The fortificationof foods with functional food ingredients will soon be seen on the market with anincrease in nutritional claims, such as medically beneficial nano- or microcapsules asalternative healthy foods. Nanoparticles will also enable the production of healthyjunk foods, that now are rich in fats, such as ice-cream and chocolate, by preventing theabsorption of fats and sugar. They can enhance the market share of calorie-rich foodsfortified with vitamins and fibre-fortified as a health enhancer by weight reducing(Miller, 2008). Most food polymers are nanosized, which include lipids and polysaccha-rides composed of linear polymers, whereas proteins are of globular polymers of a sizeof 1–10 nm. Their functionality is greatly enhanced by the encapsulation or reduction oftheir size to nanoforms of self-assembled nanostructures (Chen et al., 2006). Recentlynanoceuticals have claimed to have more health benefits in the food industries; somerecent health claims includes fortification of carotenoids’ nanoparticles in fruit drinks,enhancement of selenium intake by Chinese nanotea, and enhancement of mineraluptake by nanosilver or nanogold. Although nano- or microencapsulation technologieshave been used for several years in other sectors, food utilization is very limited andit is compromised by the very limited array of functional, generally recognized as safe(GRAS) encapsulating agents and technologies.

1.7 Nano- or microencapsulation technologies:industrial perspectives and applications in thefood market

Over the last few decades, nano- or microencapsulation technology has developed intoa large-scale business, becoming a multimillion market with the impact of nano- ormicrotechnology. It will employ more than 1.5 to 2 million workers and the expectedbusiness trade will come to about 0.5 to one trillion U.S. dollars by 2015 (Neethirajanand Jayas, 2011). From the evidence of various analyses, patent applications, and paperreports, the nano- or microencapsulation technologies have a large impact on differentfood aspects and associated industries (Neethirajan and Jayas, 2011). Research alsodiffers based on the companies and location, according to the research by Lux, thenanotechnology industry was expected to grow about 2.6 trillion US$ in manufacturedproducts by the year 2014. According to the U.S. Department of Agriculture (USDA),the global impact of nanoproducts will be 1 trillion US$ annually by 2015. In the foodand drink sector, it might reach about 3.2 billion US$ in 2015 (UK, 2010). A recentreport suggested that there may be about 400 companies involved in the nanosizeproduction of food materials (Neethirajan and Jayas, 2011). This number was expectedto reach about 1000 by 2015 (Joseph and Morrison, 2006). The sale, the growth, thetypes, and the benefits of functional food are shown in Figures 1.2, 1.3 and 1.4. Nano- or

1.7 NANO- OR MICROENCAPSULATION TECHNOLOGIES 7

22,230

2007

37

Sav

ory

snac

ks

428

Oth

ers

1685

Bak

ery

and

cere

als

3210

Dai

ry

3220

Sof

t drin

ks

36,000

2012

Figure 1.2 Varieties of functional food sales growth from 2007 to 2012 (US$).

78,300

2007

111,100

Bev

erag

es

95,000

Foo

ds

127,992

2013

Figure 1.3 Type of functional food sales growth from 2007 to 2012 (US$).

microencapsulation production for the encapsulation of various functional compoundsis one of the emerging fields in encapsulation applied to the food industry. Some of theapplications are given below and detailed studies are provided in the chapters in thisvolume. Various functional compounds, such as vitamins A and E, isoflavones, phytos-terols, lycopene, and lutein are available (NutraLease, 2011a). Their main technologyinvolves the self-assembled nanoemulsions for their higher bioavailability to the human


22,229

2007

22,609

Gut

hea

lth

23,689

Hea

rt h

ealth

24,398

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Figure 1.4 Benefit from functional foods sale growth from 2007 to 2012 (US$).

body, and better encapsulation can be achieved (NutraLease, 2011b). In addition tothe availability of their functional compounds, nanotechnology can also protect the fla-vor compounds under various pHs and temperatures with higher stability (NutraLease,2011c). Another company called Aquanova has produced novel beverage solutions withhealthy functional compounds rich in co-enzymes, vitamins, and natural colorants. Thenovel encapsulated beverages are also stable under various environmental conditionswith the standardized additive concentrations. Some multinational companies, such asNestlé and Unilever, which are well known worldwide, are also developing functionalfoods using the encapsulation technologies, and their well-known products are low fatice cream with 1% fat content.

In spite of various nano- or microencapsulation technologies being applied in thenano-industries, various countries lack regulatory systems and a framework in relationto the nanomaterials. The reason for most concern is their minute scale which can makethem go deeper into the human body, thus being unable to be detected. Before varioushealth risks from consumption of nanoproducts surface, the countries where regula-tions are still lacking regarding these technologies should be identified. Even thoughlegislation is still being adapted, other actions may be taken to improve consumer trustin the food encapsulated with nano-sized particles.

1.8 Overview of the bookThere have been very few publications available on the nano- or microencapsulationof bioactive and nutraceutical compounds in food, and the characterization of nanoen-capsulated foods, therefore, toxicity studies, and their regulations have not receivedmuch research attention. This book is therefore unique as it also extensively covers

1.8 OVERVIEW OF THE BOOK 9

bioactivity, toxicity, and the regulations regarding nano- or microencapsulated foods byinternationally renowned scientists who are at the forefront of research into nano- ormicroencapsulated foods and their toxicity and regulations. It represents the best avail-able current knowledge and up-to-date information written by world authorities andexperts in the field of nano- or microencapsulation of various functional compounds.

This book will be of interest to readers around the world, including health-consciousconsumers, students, and scientists who are looking for valuable scientific informationon functional compound encapsulations with regards to health benefits. It not onlycontains rich compilations of a variety of current research data on nano- or microencap-sulation for foods, but it also describes the functional compounds’ benefits to health inconsumption. Other integral aspects of regulations and toxicity are also included, suchas the regulations on nano- or micro encapsulation of functional compounds in food invarious countries.

Part I presents an overview of nano- or microencapsulation of various functionalfood materials, the wall materials used for the encapsulation, its characterization andits application in various food types. This part covers the rationales and concepts usedin nanomaterials, nano- or microencapsulation of foods.

Chapter 2 by Jingyuan Wen, Guanyu Chen, and Raid G. Alany focuses on theconcepts involved in nano- or microencapsulation for food, to present up-to-datereferences, research data, and scientific information in the field of encapsulation offood ingredients with respect to those beneficial to health. They discuss the technology,its significant advantages, the commonly used materials, fabrication techniques, andthe factors influencing delivery system optimization for nutraceuticals. Some repre-sentative studies of nano- and microencapsulation of food ingredients via differentdelivery routes are reported.

Chapter 3 by Sundaram Gunasekaran and Sanghoon Ko discusses the rationales forthe use of nano- or microencapsulation for foods.

Chapter 4 by Minh-Hiep Nguyen, Nurul Fadhilah Kamalul Aripin, and Hyun-JinPark deals with common techniques used for determining the characteristics of nanoen-capsulation. In particular, techniques, such as laser diffraction, dynamic light scattering,acoustic spectroscopy, sedimentation, microscopy, or image analysis, can be appliedto measure particle size and particle size distribution. Electrophoretic light scatteringand the electroacoustic technique are commonly used to determine the zeta potentialof nano- and microcapsules. In addition, optical microscopy, confocal laser scanningmicroscopy, transmission electron microscopy, or scanning electron microscopy can beapplied to observe the morphology of nano- and microcapsules. On the other hand,the membrane flexibility can be measured using fluorescence anisotropy, extrusion,or electron spin resonance. Moreover, the methods used to determine the stability ofnano- and microcapsules are also discussed in this chapter. Finally, to measure encap-sulation efficiency, there are two major steps (separation and analysis). However, theseparation stage, in which nano- and microcapsules are separated from unencapsulatedactive ingredients, is usually more difficult than the analysis stage. Therefore, commontechniques used in separation, such as centrifugation, filtration, size exclusion chro-matography, and dialysis, are also introduced in this chapter. This chapter not onlysupplies general information about the common techniques used in the characterizationof nano- and microcapsules, but also indicates that each technique has its advantagesand disadvantages.


Chapter 5 by Mi-Jung Choi and Hae-Soo Kwak deals with the current strategiesinvolved in the development of nano-materials, nano- or microencapsulation of foods.It presents an overview of current and projected applications of nano- or microencapsu-lation for food ingredients in the food and agricultural sectors. Overall, Part I deals withthe encapsulation development from the micro-size to the nano-size from its beginningsto the current technologies used in its applications.

Part II looks closely at the various functional compounds for encapsulation, such asphytochemicals, probiotics, minerals, vitamins, and flavors and its application in variousfood products. Chapter 6 by Sung Je Lee and Marie Wong deals with the current trendsin the encapsulation of phytochemicals and their application in the development of var-ious functional beverages without affecting their physicochemical properties. Chapter 7by Kasipathy Kailasapathy deals mainly with the microencapsulation of probiotics andits potential applications in various food products, including beverages, dairy products,meat products, and some vegetarian foods. Since probiotic bacteria are micro-sized,this chapter focuses mainly on microencapsulation. The current microencapsulationtrends reduce the main problem of the survival rate of the microbes and in the nearfuture these will overcome this and open the door to the marketing of these products.Chapter 8 by Florentine M. Hilty and Michael B. Zimmermann is mainly focused onthe nanostructured minerals used in food and nutritional applications. Mineral defi-ciencies (e.g. iron, zinc, and calcium) are major global health problems affecting bothlow- and high-income countries. Correction of these deficiencies through food forti-fication and/or supplementation requires the application of mineral compounds thatare stable when added to reactive food matrices and that are well absorbed. Nanos-tructuring of minerals may provide these performance characteristics. For example,the nanostructuring of poorly soluble iron compounds that cause little color change infoods, such as iron and zinc-containing phosphates, and oxides, sharply increases theirsolubility and their iron bioavailability. Similarly, nanostructured selenium and calciumcompounds have characteristics that may allow them to be used as food fortificants andnutritional supplements. However, for most nanostructured minerals, there is a lackof data on potential gastrointestinal toxicity as well as long-term shelf-life in potentialfood vehicles. Future research will clarify whether these nanostructured minerals willprove useful for nutritional applications.

Chapter 9 by Ashok R. Patel and Bhesh Bhandhari covers the encapsulationof vitamins in foods. The encapsulation and stabilization of micronutrients, suchas vitamins, have received increased attention from academic researchers and inparticular from industrial scientists, due to their ease in industrial feasibility. In today’smodern scenario, with increased consumer awareness and resultant increase in thedemands for modern fortified food products, nano- and microencapsulation areconsidered an integral part of the product development in the food manufacturingindustries. In this chapter, an overview of the formulation and delivery challengesassociated with vitamins is discussed with respect to the need for their encapsulation inmicro-/nanostructures. In addition, some of the latest developments in encapsulationof vitamins are detailed with the help of illustrated examples.

Flavor plays an important role in the appeal of food: It motivates us to eat and pro-vides satisfaction during food consumption. Chapter 10 by Kyuya Nakagawa deals withthe engineering aspects of nano- and microencapsulation of flavors in food systems. Fla-vor control is a challenge in food engineering; specifically, it is difficult to maintain theflavor at a desired level during processing and storage and to release it with the desired

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