ADVANCED DAIRY CHEMISTRY

ADVANCED DAIRY CHEMISTRY-l

PROTEINS

3rd Edition

PARTA

Edited by

P. F. FOX and P. L. H. McSWEENEY University College

Corle, Ireland

SPRINGER SCIENCE+BUSINESS MEDIA, LLC

ISBN 978-0-306-47271-8 ISBN 978-1-4419-8602-3 (eBook) DOI 10.1007/978-1-4419-8602-3

© 2003 Springer Science+Business Media New York Originally published by Kluwer Academic 1 Plenum Publishers, New York in 2003

http://www.wkap.com

w 9 8 7 6 5 4 3 2 1

A C.I.P. record for this book is available from the Library of Congress

AU rights reserved

No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise,

without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive

use by the purchaser of the work

CONTRIBUTORS

Francesco Addeo Dipartimento di Scienza degli Alimenti, Facolta di Agraria, Universita degli

Studi di Napoli Federico II, Portici, Italy Istituto di Scienze dell' Alimentazione del C.N.R. Via Roma 52 NC, 83100

Avellino, Italy

Keith Brew Department of Biomedical Sciences, Florida Atlantic University, 777 Glades

Road, PO Box 3091, Boca Raton, Florida 33431-0991, USA

Eleanor M. Brown Eastern Regional Research Center, US Department of Agriculture, Agricultural

Research Service, Wyndmoor, Pennsylvania 19038, USA

A. J. Carr Fonterra Research Centre, Private Bag 11 029, Palmerston North, New Zealand

L. K. Creamer Fonterra Research Centre, Private Bag 11 029, Palmerston North, New Zealand

A. Corsetti Dipartimento di Scienze degli Alimenti, Universita degli Studi di Perugia, via

S. Costanzo, 06126 Perugia, Italy

C. G. de Kruif NIZO Food Research, PO Box 20, 6710BA Ede, The Netherlands

Eric Dickinson Procter Department of Food Science, University of Leeds, Leeds LS2 9JT, UK

vi CONTRIBUTORS

Didier Dupont INRA-SRTAL, Department of Immunochemistry, BP 89, 39801 Poligny

Cedex, France

M. P. Ennis Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

Nana Y. Farkye Dairy Products Technology Center, Dairy Science Department, California

Polytechnic State University, San Luis Obispo, California 93407, USA

Harold M. Farrell, Jr. Eastern Regional Research Center, US Department of Agriculture, Agricultural

Research Service, Wyndmoor, Pennsylvania 19038, USA

Pasquale Ferranti Dipartimento di Scienza degli Alimenti, Facolta di Agraria, Universita degli

Studi di Napoli Federico II, Portici, Italy Istituto di Scienze dell' Alimentazione del C.N.R. Via Roma 52 AlC, 83100

Avellino, Italy

c. M. Fleming Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

R. J. FitzGerald Life Sciences Department, University of Limerick, Castletroy, Limerick, Ire­

land

P. F. Fox Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

M. Gobbetti Dipartimento di Protezione delle Piante e Microbiologia Applicata, Universita

degli Studi di Bari, Via G. Amendola 165/a, 70126 Bari, Italy

H. Douglas Goff Department of Food Science, University of Guelph, Guelph, Ontario NIG 2Wl,

Canada

CONTRIBUTORS vii

F. Grosclaude Laboratoire de Genetique Biochimique et de Cytogenetique, INRA, 78352

Jouy-en-Josas Cedex, France

T. P. Guinee Dairy Products Research Centre, Teagasc, Moorepark, Fermoy, Co. Cork,

Ireland

Leif Hambrreus Karolinska Institute, Department of Bioscience, Unit for Preventive Nutrition,

SE 141 57, Huddinge, Sweden

Palatasa Havea Institute of Food, Nutrition and Human Health, Massey University, Private Bag

11 222, Palmerston North, New Zealand

Peter D. Hoagland Eastern Regional Research Center, US Department of Agriculture, Agricultural

Research Service, Wyndmoor, Pennsylvania 19038, USA

C. Holt Hannah Research Institute, Ayr, KA6 5HL, Scotland, UK

D. S. Horne Charis Food Research, Hannah Research Park, Ayr, KA6 5HL, Scotland, UK

Walter L. Hurley Department of Animal Sciences, University of Illinois, 1207 W. Gregory Dr.,

Urbana, IL 61801

D. B. Hyslop Department of Food Science, University of Wisconsin-Madison, 1605 Linden

Drive, Madison, WI 53706

A. L. Kelly Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

Shuichi Kaminogawa Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1

Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

viii CONTRffiUTORS

Marie-France Laporte Dairy Research Centre STELA, Universite Laval, Pavillon Paul Comtois, room

0308, Ste-Foy, Quebec, Canada GlK 7P4

A.J. R. Law Charis Food Research, Hannah Research Park, Ayr, KA6 5HL, Scotland, UK

J. Leaver Hannah Research Institute, Ayr, KA6 5HL, Scotland, UK

Joelle Leonil Institut National de la Recherche Agronomique, Laboratoire de Recherches en

Technologie Laitiere, 65, rue de Saint-Brieuc, 35042 Rennes Cedex, France

Christine Leroux Laboratoire de Genetique biochimique et de Cytogenetique, Institut National de

la Recherche Agronomique, Domaine de Vilvert, 78352 Jouy-en-Josas Cedex, France

Bo Lonnerdal Department of Nutrition, University of California, Davis, California 95616,

USA

John A. Lucey Department of Food Science, University of Wisconsin-Madison, 1605 Linden

Drive, Madison, Wisconsin 53706, USA

Edyth L. Malin Eastern Regional Research Center, US Department of Agriculture, Agricultural

Research Service, Wyndmoor, Pennsylvania 19038, USA

Patrice Martin Laboratoire de Genetique Biochimique et de Cytogenetique, Institut National

de la Recherche Agronomique, Domaine de Vilvert, 78352 Jouy-en-Josas Cedex, France

P. L. H. McSweeney Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

H. Meisel Bundesanstalt fur Milchforchung, Insitut fur Chemie und Technologie der

Milch, PO Box 6069, D-24121, Kiel, Germany

CONTRIBUTORS ix

D. M. Mulvihill Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

K. F. Ng-Kwai-Hang

Faculty of Agricultural and Environmental Sciences, Department of Animal Science, McGill University, MacDonald Campus, 21,111 Lakeshore, Ste-Anne-de­Bellevue, Quebec, Canada H9X 3V9

Johannes A. Nieuwenbuijse Friesland Consumer Products Europe, Research and Development

Leeuwarden, PO Box 226, 8901 MA Leeuwarden, Netherlands

J. E. O'Connell Department of Food Science, Food Technology and Nutrition, University Col­

lege, Cork, Ireland

Gunilla Olivecrona Department of Medical Biosciences, University of Umea, S-90187 Umea,

Sweden

Thomas Olivecrona Department of Medical Biosciences, University of Umea, S-90187 Umea,

Sweden

M.Ollivier-Bonsquet Laboratoire de Biologie Cellulaire et Moleculaire, INRA, 78352 Jouy-en-Josas

Cedex, France

Paul Paquin Dairy Research Centre STELA, Universite Laval, Pavillon Paul Comtois, room

1401, Ste-Foy, Quebec, Canada GIK 7P4

Kenneth M. Pruitt University of Alabam.a at Birmingham, 701 S. 19th St., Room 134, Lyons­

Harrison Research Building, Birmingham, Alabama 35294-0007

Shakeel-Ur-Rehman Dairy Products Technology Center, Dairy Science Department, California

Polytechnic State University, San Luis Obispo, California 93407

x CONTRIBUTORS

Lindsay Sawyer Structural Biochemistry Group, The University of Edinburgh, Swann Building,

King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, UK

D. B. Shennan Hannah Research Institute, Ayr, KA6 5HL, Scotland

Harjinder Singh Institute of Food, Nutrition and Human Health, Massey University, Private Bag

11 222, Palmerston North, New Zealand

C. R. Southward Fonterra Research Centre, Private Bag 11 029, Palmerston North, New Zealand

L. Stepaniak Department of Food Science, Agricultural University, N-1430 Aas, Norway

Harold E. Swaisgood Department of Food Science, Southeast Dairy Foods Research Center, North

Carolina State University, Raleigh, North Carolina 27695-7624, USA

Mamoru Totsuka Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1

Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

Louise Tremblay Dairy Research Centre STELA, Universite Laval, Pavillon Paul Comtois, room

1316, Ste-Foy, Quebec, Canada GlK 7P4

Martinus A. J. S. van Boekel Department of Food Science, Wageningen Agricultural University, PO Box

8129,6700 EV, Wageningen, Netherlands

Senen Vilaro Department de Biologia Cellular, University of Barcelona, 080288 Barcelona,

Spain

J. L. Vilotte Laboratoire de Genetique Biochimique et de Cytogenetique and Laboratoire de

Biologie Cellulaire et Moleculaire, INRA, 78352 Jouy-en-Josas Cedex, France

C. B. A. Whitelaw Division of Molecular Biology, Roslin Institute (Edinburgh), Roslin, Mid­

lothian EH25 9PS, UK

PREFACE TO THE THIRD EDITION

Advanced Dairy Chemistry-l: Proteins is the first volume of the third edition of the series on advanced topics in Dairy Chemistry, which started in 1982 with the publication of Developments in Dairy Chemistry. This series of volume~ is intended to be a coordinated and authoritative treatise on Dairy Chemistry. In the decade since the second edition of this volume was published (1992), there have been considerable advances in the study of milk proteins, which are reflected in changes to this book.

All topics included in the second edition are retained in the current edition, which has been updated and considerably expanded from 18 to 29 chapters. Owing to its size, the book is divided into two parts; Part A (Chapters 1-11) describes the more basic aspects of milk proteins while Part B (Chapters 12-29) reviews the more applied aspects. Chapter 1, a new chapter, presents an overview of the milk protein system, especially from an historical viewpoint. Chapters 2-5, 7-9, 15, and 16 are revisions of chapters in the second edition and cover analytical aspects, chemical and physiochemical properties, biosynthesis and genetic polymorphism of the principal milk proteins. Non-bovine caseins are reviewed in Chapter 6. Biological properties of milk proteins, which were covered in three chapters in the second edition, are now expanded to five chapters; a separate chapter, Chapter 10, is devoted to lactoferrin and Chapter 11, on indigenous enzymes in milk, has been restructured and expanded. Nutritional aspects, allergenicity of milk proteins, and bioactive peptides are discussed in Chapters 12, 13, and 14, respectively. Because of significant developments in the area in the last decade, Chapter 17 on genetic engineering of milk proteins has been included. Various aspects of the stability of milk proteins are covered in Chapter 18 (enzymatic coagulation), Chapter 19 (heat­induced coagulation), Chapter 20 (age gelation of sterilized milk), Chapter 21 (ethanol stability), and Chapter 22 (acid coagulation, a new chapter).

The book includes four chapters on the scientific aspects of protein-rich dairy products (milk powders, Chapter 23; ice cream, Chapter 24; cheese, Chapter 25; functional milk proteins, Chapter 26) and three chapters on technologically impor­tant properties of milk proteins (surface properties, Chapter 27; thermal denatura­tion aggregation, Chapter 28; hydration and viscosity, Chapter 29).

Like its predecessors, this book is intended for academics, researchers at

xii PREFACE TO THE THIRD EDITION

universities and industry, and senior students; each chapter is referenced exten­sively.

We wish to thank sincerely the 60 contributors to the 29 chapters of this volume, whose cooperation made our task as editors a pleasure. The generous assistance of Ms. Anne Cahalane is gratefully acknowledged.

P. F. Fox P. L. H. McSweeney

University College Cork, Ireland

CONTENTS

1. Milk proteins: general and historical aspects . . . . . . . . . . . . . . . . . 1 P. F. Fox 1.1 Introduction......................................... 1 1.2 Preparation of casein and whey proteins .................. 5 1.3 Comparison of key properties of casein and whey proteins ... 9 1.4 Heterogeneity and fractionation of casein ................. 11 1.5 Application of gel electrophoresis to the study of milk

proteins ............................................ 14 1.6 Microheterogeneity of the caseins ....................... 15 1.7 Nomenclature of milk proteins. . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.8 Whey proteins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.9 Fractionation of whey proteins. . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.1 0 Some major characteristics of whey proteins .............. 20 1.11 Molecular properties of the milk proteins ................. 28 1.12 Casein micelle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1.14 Summary and perspective

References .......................................... 41

2. Quantitation of proteins in milk and milk products ... . . . . . . . . 49 L. Tremblay, M. F. Laporte, J. Leonil, D. Dupont and P. Paquin 2.1 Introduction......................................... 51 2.2 Definitions of protein and analytical performance .......... 52 2.3 Reference and routine methods ......................... 56 2.4 Separate determination and characterization of individual

proteins in milk and dairy products ...................... 80 2.5 Immunochemical methods ............................. 106

References .......................................... 119

xiv CONTENTS

3. Chemistry of the caseins .................................. 139 H. E. Swaisgood 3.1 Introduction.......................................... 139 3.2 Protein composition of milk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 3.3 Isolation and identification of the caseins .................. 145 3.4 Primary structure and chemical composition of the caseins. . . . 154 3.5 Physicochemical characteristics of the caseins .............. 176 3.6 Projection of future work ............................... 187

References ........................................... 187

4. Higher order structures of the caseins: a paradox? ........... 203 H. M. Farrell, Jr., E. M. Brown, P. D. Hoagland, and E. L. Malin 4.1 Introduction and rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 4.2 Molecular modelling of as I-casein interactions and support

from experimental data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 4.3 The tensegrity hypothesis and resolution . . . . . . . . . . . . . . . . . .. 225

References ........................................... 229

s. Casein micelle structure, functions and interactions . . . . . . . . . . . 233 C. G. De Kruif and C. Holt 5.1 Introduction.......................................... 233 5.2 Biological functions of the caseins ....................... 234 5.3 Structure of the individual caseins ........ . . . . . . . . . . . . . . . . 236 5.4 Size and voluminosity of the casein micelle. . . . . . . . . . . . . . . . 241 5.5 Surface structure of the casein micelle .................... 244 5.6 Internal structure of the casein micelle .................... 246 5.7 Dissociation of casein micelles in response to environmental

change..... . ..... ... . .... . ....... .... . . ..... ... ..... 254 5.8 Aggregation, gelation and syneresis. . . . . . . . . . . . . . . . . . . . . . . 258

Acknowledgements .................................... 270 References ........................................... 270

6. Non-bovine caseins: quantitative variability and molecular diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 P. Martin, P. Ferranti, C. Leroux and F. Addeo 6.1 Introduction .......................................... 277 6.2 The casein gene locus and quantitative variability ........... 278 6.3 Primary structure of caseins: an interspecies comparison. . . . . . 281 6.4 Molecular diversity of caseins: interspecies variability . . . . . . . . 289 6.5 Micelle organisation ................................... 301 6.6 Analytical tools ....................................... 303

CONTENTS xv

6.7 Concluding remarks .................................. 308 References .......................................... 310

7. p-Lactoglobulin ......................................... 319 L. Sawyer 7.1 Introduction......................................... 319 7.2 Biosynthesis and secretion ............................. 320 7.3 Distribution......................................... 321 7.4 Isolation............................................ 324 7.5 Genetic variants and primary structure ................... 325 7.6 Molecular structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 7.7 Solution studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 7.8 Denaturation ........................................ 337 7.9 Secondary structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 7.10 Conformational changes and folding studies. . . . . . . . . . . . . . . 342 7.11 Amino acid environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 7.12 Site-directed mutagenesis .............................. 347 7.13 Binding studies ...................................... 348 7.14 Homologous proteins ................................. 358 7.15 Function..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 7.16 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363

References .......................................... 363

8. a-Lactalbumin .......................................... 387 K. Brew 8.1 Introduction......................................... 387 8.2 Overview of earlier work .............................. 388 8.3 Structure ........................................... 392 8.4 Aspects of a-lactalbumin function. . . . . . . . . . . . . . . . . . . . . .. 401 8.5 Conclusion.......................................... 410

Acknowledgement. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 412 References .......................................... 412

9. Immunoglobulins in mammary secretions ................... 422 W. L. Hurley 9.1 Introduction......................................... 422 9.2 Immunity and immunoglobulins. . . . . . . . . . . . . . . . . . . . . . . . . 422 9.3 Transfer of passive immunity. . . . . . . . . . . . . . . . . . . . . . . . . .. 431 9.4 Control of transport and mammary gland immunity. . . . . . . .. 436 9.5 Interactions with other proteins in milk . . . . . . . . . . . . . . . . . .. 437 9.6 Manipulation of mammary gland immunity ............... 437

xvi CONTENTS

9.7 Conclusion References

10. Lactoferrin ........................................... . B. LOnnerdal 10.1 Introduction .................................... . 10.2 Biochemical properties of lactoferrin ................ . 10.3 Molecular biology of lactoferrin .................... . 10.4 Biological functions of lactoferrin .................. . 10.5 Lactoferrin receptors ............................. . 10.6 Implications and significance ...................... .

References ..................................... .

11.1 Indigenous enzymes in milk P. F. Fox 11.1 General introduction

References ..................................... .

11.2 Lipases in milk ........................................ . T. Olivecrona, S. Vilam, and G. Olivecrona 11.2.1 Introduction .................................... . 11.2.2 Role of the lipoprotein lipase in metabolism of plasma

lipoproteins ..................................... . 11.2.3 Structure ....................................... . 11.2.4 Catalytic properties .............................. . 11.2.5 Apolipoprotein CII ............................... . 11.2.6 Product inhibition ................................ . 11.2.7 Evolutionary aspects ............................. . 11.2.8 LPL in the mammary gland ....................... . 11.2.9 Synthesis and secretion of milk .................... . 11.2.10 State of LPL in milk ............................. . 11.2.11 Lipolysis in milk ................................ .

References ..................................... .

11.3 Indigenous proteinases in milk ........................... . A. L. Kelly and P. L. H. McSweeney 11.3.1 Introduction .................................... . 11.3.2 Plasmin system in milk ........................... . 11.3.3 Somatic cell proteinases .......................... .

References ..................................... .

438 439

449

449 449 452 453 459 461 461

467

467 470

473

473

474 475 479 480 481 481 483 484 486 487 488

495

495 496 505 512

CONTENTS XVll

11.4 Indigenous pbospbatases in milk .......................... 523 Shakeel-Ur-Rehman, C. M. Fleming, N. Y. Farkye, and P. F. Fox 11.4.1 Introduction ..................................... 523 11.4.2 Acid phosphatase ................................. 525 11.4.3 Milk alkaline phosphatase .......................... 530

References ...................................... 539

11.5 Indigenous nucleases in milk ............................. 545 L. Stepaniak, C. M. Fleming, M. Gobbetti, A. Corsetti, and P. F. Fox 11.5.1 Introduction ..................................... 545 11.5.2 Deoxyribonucleases ............................... 545 11.5.3 Ribonucleases.................................... 547 11.5.4 Ribonucleases in milk ............................. 549 11.5.5 Catalytic antibodies (abzymes) with oligonuc1ease activity 552

References ...................................... 557

11.6 Lactoperoxidase ........................................ 563 K. Pruitt 11.6.1 Introduction ..................................... 563 11.6.2 Structure of bovine lactoperoxidase (bLPO) ........... 564 11.6.3 Major reactions of bovine lactoperoxidase ... . . . . . . . . . . 566

11.6.4 Components of the lactoperoxidase system in bovine milk 567 11.6.5 Biological significance of the bovine lactoperoxidase

system 11.6.6 Conclusions ..................................... 568

References ...................................... 568

11.7 Other enzymes ......................................... 571 N. Y. Farkye 11.7.1 Introduction ..................................... 571 11.7.2 L-Lactate dehydrogenase (EC 1.1.1.27) ............... 571 11.7.3 Catalase (EC 1.11.1.6) .. .. ... ......... . ......... . .. 572 11.7.4 Glutathione peroxidase (EC 1.11.1.9) .. ..... . .... ..... 574 11.7.5 Superoxide dismutase (EC 1.15.1.1) ............. . . . . . 574 11.7.6 Xanthine oxidase (EC 1.1.3.22) ..................... 576 11.7.7 Sulphydryl oxidase................................ 578 11. 7.8 'Y-Glutamyl transferase (EC 2.3.2.2) .................. 579 11.7.9 Amylases ....................................... 580 11.7.10 Lysozyme (EC 3.2.1.17) ........................... 581 11.7.11 N-Acetyl-I3-D-glucosaminidase (EC 3.2.1.30) .......... 583

xviii CONTENTS

11.7.12 a-Mannosidase (EC 3.2.1.24) ....................... 584 11.7.13 j3-Glucuronidase (EC 3.2.1.31) ...................... 584 11.7.14 5' -Nucleotidase (EC 3.1.3.5) . ... .... . ......... ... ... 585 11.7.15 Adenosine triphosphatase (EC 3.6.1.3) ................ 586 11. 7 .16 Fructose-bisphosphate aldolase (EC 4.1.2.13) .......... 586 11.7.17 Other enzymes. . ..... . . . ... ... .... . ..... ......... 591 11. 7.18 Conclusions ..................................... 591

Acknowledgment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591 References ...................................... 591

CONTENTS

12. Nutritional aspects of milk proteins ....................... 605 L. Hamhrreus and B. LOnnerdal 12.1 Introduction....................................... 605 12.2 The role of dairy products in the human diet ............ 607 12.3 Composition of milk proteins. . . . . . . . . . . . . . . . . . . . . . . . . 609 12.4 Protein requirement in humans. . . . . . . . . . . . . . . . . . . . . . . . 610 12.5 What is meant by the nutritive value of a protein? . . . . . . . . 612 12.6 Estimation of the nutritional value of food proteins ....... 614 12.7 Composition of milk protein ......................... 620 12.8 Nutritional versus physiological roles of milk proteins .... 628 12.9 Can the nutritional value of milk proteins be damaged? ... 629 12.10 Role of milk proteins in the human diet ................ 630 12.11 Milk proteins in clinical dietetics. . . . . . . . . . . . . . . . . . . . . . 633 12.12 Milk for high-energy consumers ...................... 634 12.13 Can milk proteins be hazardous? ...................... 636 12.14 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639

References ........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640

13. AIlergenicity of milk proteins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 647 S. Kaminogawa and M. Totsuka 13.1 Introduction....................................... 647 13.2 Characteristics of milk allergy ........................ 647 13.3 Mechanism of onset of milk allergy ................... 648 13.4 Allergenicity of milk proteins ........................ 650 13.5 Allergenicity of heat-processed milk proteins and

hydrolysed infant formulae . . . . . . . . . . . . . . . . . . . . . . . . . . . 652 13.6 Antigenic and allergenic structure of milk allergens . . . . . . . 654 13.7 Antigenic microstructure of milk allergens and suppression

of immune allergic reactions by its alteration ............ 663 13.8 Concluding remarks ................................ 667

References ........................................ 668

xiv CONTENTS

14. Milk protein bydrolysates and bioactive peptides ............ 675 R. J. FitzGerald and H. Meisel 14.1 Introduction....................................... 675 14.2 Structure and biological activity. . . . . . . . . .. . . . .. . . . . . . . 675 14.3 Generation of bioactive peptides ...................... 684 14.4 Enrichment of bioactive peptides . . . . . . . . . . . . . . . . . . . . . . 686 14.5 Physiological significance. . . . . . . . . . . . . . . . .. . . . . . . . .. . 687 14.6 Conclusion........................................ 690

Acknowledgement. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 691 References ........................................ 691

15. Biosynthesis of milk proteins ............................. 699 J. L. Vilotte, C. B. A. Whitelaw, M. Ollivier-Bousquet, and D. B. Shennan 15.1 Introduction....................................... 699 15.2 Milk protein gene structure .......................... 700 15.3 Milk protein-encoding gene expression and regulation. . . . . 705 15.4 Intracellular transport and co- and post-translational

processing of milk proteins .......................... 714 15.5 Amino acid transport by the mammary gland. . . . . . . . . . . . 720

References ........................................ 726

16. Genetic polymorphism of milk proteins .................... 739 K. F. Ng-Kwai-Hang and F. Grosclaude 16.1 Introduction....................................... 739 16.2 Methods of detecting genetic polymorphism.. . . . .. . . . . . . 740 16.3 Occurrence of genetic polymorphism in bovine species. . . . 748 16.4 Molecular basis for genetic polymorphism in bovine

species ........................................... 751 16.5 Occurrence and molecular basis of genetic polymorphism

in species other than bovine. . . . . . . . . . . . . . . . . . . . . . . . . . 758 16.6 Linkage between milk protein genes. . .. . . . . . . . .. . . . . .. 763 16.7 Frequency distribution of genetic variants in cattle species 766 16.8 Frequency distribution of genetic variants in other species 776 16.9 Milk protein polymorphism as marker genes in bovine

species ........................................... 778 16.10 Genetic polymorphism and properties of bovine milk ..... 785 16.11 Genetic polymorphism and properties of milk in other

species ........................................... 790 16.12 Concluding remarks ................................ 791

References ........................................ 792

CONTENTS xv

17. Genetic engineering of milk proteins . . . . . . . . . . . . . . . . . . . . . . . 817 J. Leaver and A. J. R. Law 17.1 Introduction....................................... 817 17.2 Expression of milk proteins in non-mammalian systems ... 819 17.3 Genetic engineering of milk proteins in animals . . . . . . . . . . 821 17.4 Modification of the nutritional properties of milk . . . . . . . . . 825 17.5 The mammary gland as a factory for the manufacture of

therapeutic proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 829 17.6 Future developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831

Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 832 References ........................................ 832

18. Enzymatic coagulation of milk . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839 D. B. Hyslop 18.1 Introduction....................................... 839 18.2 Measurement of enzyme activity ...................... 841 18.3 Michaelis-Menten kinetics ........................... 843 18.4 Surface enzyme kinetics ............................. 845 18.5 Diffusion kinetics .................................. 847 18.6 The enzyme-substrate complex ....................... 849 18.7 Rennet substitutes .................................. 851 18.8 Pretreatment of data ................................ 852 18.9 Casein stability .................................... 855 18.10 Measurement of aggregation ......................... 858 18.11 Modelling the total clotting reaction ................... 862 18.12 Time dependent rate constants. . . . . . . . . . . . . . . . . . . . . . . . 866 18.13 Conclusion...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 869

References ........................................ 869

19. Heat-induced coagulation of milk ......................... 879 J. E. O'Connell and P. F. Fox 19.1 Abstract.......................................... 879 19.2 Heat stability of milk ............................... 879 19.3 Compositional factors that affect the heat stability of milk 882 19.4 Processing conditions and additives that affect stability. . . . 897 19.5 Heat-induced changes ............................... 903 19.6 pH dependence and mechanism of heat-induced coagulation 924 19.7 Suggestions for further work ......................... 930

References ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 930

xvi CONTENTS

20. Protein stability in sterilised milk and milk products.. . . . . . . . 947 J. A. Nieuwenhuijse and M. A. J. S. van Boekel 20.1 Introduction........................................ 947 20.2 Methods of preservation .............................. 948 20.3 Physical and chemical changes caused by heating and

storage ........................•................... 948 20.4 Physical instability .................................. 959 20.5 Concluding remarks ................................. 969

References ......................................... 969

21. Ethanol stability ........................................ 975 D. S. Home 21.1 Introduction........................................ 975 21.2 Alcohol stability test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976 21.3 Ethanol stability and casein micelle structure ............. 983 21.4 Mechanism for alcohol destabilization of milk protein. . . . . . 993 21.5 Practical applications ................................ 994

References ......................................... 995

22. Acid coagulation of milk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1001 J. A. Lucey and H. Singh 22.1 Introduction........................................ 1001 22.2 Acidification of milk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1002 22.3 Formation and properties of acid-induced milk gels. . . . . . . . 1005 22.4 Concluding remarks ................................. 1019

References ......................................... 1021

23. Manufacture and properties of milk powders ............... 1027 A. L Kelly, J. E. O'Connell and P. F. Fox 23.1 Introduction ........................................ 1027 23.2 Technology of milk powder manufacture ................ 1028 23.3 Types of milk powders. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 1036 23.4 Physico-chemical changes that occur during drying. . . . . . . . 1039 23.5 Functional properties of milk powders .................. 1041 23.6 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. . . . . . . . . 1054

References ......................................... 1054

24. Ice cream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1063 H. D. Goff 24.1 Introduction ...................... .'................. 1063 24.2 Ice cream manufacture ............................... 1064 24.3 Sources of milk proteins for ice cream .................. 1069

CONTENTS xvii

24.4 Structure of ice cream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1071 24.5 Functional roles of milk proteins in ice cream ............ 1072 24.6 Protein analysis in ice cream .......................... 1077 24.7 Conclusion.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1078

References ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1079

25. Role of protein in cheese and cheese products . . . . . . . . . . . . . . . 1083 T. P. Guinee 25.1 Introduction ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1084 25.2 Contribution of protein to cheese structure ............... 1085 25.3 Role of protein in the curd texturization and plasticization

processes in the manufacture of Cheddar and pasta jilata varieties ........................................... 1092

25.4 Cheese yield ....................................... 1098 25.5 Effect of protein on the rheological properties of unheated

cheese ............................................ 1110 25.6 Effect of protein on the functional properties of unheated

cheese ............................................ 1127 25.7 Effect of protein on the functional properties of heated

cheese ............................................ 1128 25.8 Contribution of protein to the formation of pasteurized

processed cheese products (PCPs) and analogue cheese products (ACPs) .................................... 1147

25.9 Conclusions ........................................ 1158 References ............................. . . . . . . . . . . . . 1159

26. Functional milk proteins: production and utilization ......... 1175 D. M. Mulvihill and M. P. Ennis 26.1 Introduction........................................ 1175 26.2 Production of milk protein products .................... 1176 26.3 Food uses of milk protein products ..................... 1207 26.4 Future developments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1219

References .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1219

27. Interfacial, emulsifying and foaming properties of milk proteins ............................................... 1229 E. Dickinson 27.1 Introduction .............. . . . . . . . . . . . . . . . . . . . . . . . . . . 1229 27.2 Adsorbed layer structure of pure proteins ................ 1230 27.3 Surface rheology of milk proteins ...................... 1234 27.4 Competitive adsorption and protein-surfactant interactions .. 1236 27.5 Testing the emulsifying and foaming properties of proteins. . 1239

xviii CONTENTS

27.6 Flocculation, creaming and rheology of emulsions . . . . . . . . . 1242 References ......................................... 1246

28. Thermal denaturation, aggregation and gelation of whey proteins ............................................... 1261 H. Singh and P. Havea 28.1 Introduction........................................ 1261 28.2 Heat-induced unfolding and aggregation of whey proteins .. 1263 28.3 Heat-induced gelation of whey proteins ................. 1273 28.4 Concluding remarks ................................. 1281

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1282

29. Protein hydration and viscosity of dairy fluids .............. 1289 A. J. Carr, C. R. Southward and L. K. Creamer 29.1 Introduction........................................ 1289 29.2 Whey protein products ............................... 1290 29.3 Casein-based products. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1293 29.4 Skim milk and whole milk protein systems .............. 1310 29.5 Conclusions ........................................ 1316

Acknowledgements .................................. 1317 References ......................................... 1318