FOOD BIOCHEMISTRY

ELLIS HORWOOD SERIES IN FOOD SCIENCE AND TECHNOLOGY

Editor-in-Chief: I .D . M O R T O N , Professor and formerly Head of Department of Food and Nutritional Science, King's College, London. Series Editors: D . H . WATSON, Ministry of Agriculture, Fisheries and Food, and M . J . LEWIS, Department of Food Science and Technology, University of Reading

Food Biochemistry C. Alais & G. Linden Fats for the Future R .C. Cambie Food Handbook C . M . E . Catsberg & G.J .M. Kempen-van Dommelen Determination of Veterinary Residues in Food N.T. Crosby & C M . Clark Food Policy Trends in Europe: Nutrition, Technology, Analysis and Safety H . Deelstra, M . Fondu,

W. Ooghe & R. van Havere Principles and Applications of Gas Chromatography in Food Analysis M . H . Gordon Nitrates and Nitrite in Food and Water M.J . Hill Technology of Biscuits, Crackers and Cookies, 2nd Edition D.J.R. Manley Feta and Related Cheeses R . K . Robinson & A . Y . Tamime Vitamins and Minerals M . Tolonen

Applied Human Nutrition: For Food Scientists and Home Economists A . F . Walker

Forthcoming titles Traditional Fermented Foods M . Z . AH & R.K. Robinson Food Microbiology, Volumes 1 & 2 C M . Bourgeois, J.F. Mescle & J. Zucca Food Container Corrosion D.R. Davis & A . V . Johnston Technology of Meat and Meat Products J. P. Girard Dairy Technology A . Grandison, M.J . Lewis & R . A . Wilbey Separation Processes: Principles and Applications A . Grandison & M.J . Lewis Microbiology of Chilled and Frozen Foods W.F. Harrigan Modern Food Processing J. Lamb Food Technology Data M.J . Lewis Education and Training in Food Science: A Changing Scene I.D. Morton Modified Atmosphere Packaging of Food B. Ooraikul & M . E . Stiles Food: Production, Preservation and Safety, Volumes 1 & 2 P. Patel Handbook of Edible Gums K .R . Stauffer Natural Toxicants in Food D . H . Watson

FOOD BIOCHEMISTRY

C. A L A I S G. L I N D E N both Professors of Biochemistry University of Nancy, France

Translation Editor I. M O R T O N

Translator A. W H I T E H E A D

Springer-Science+Business Media, B.V.

© Springer Science+Business Media Dordrecht 1991 Originally published by Chapman and Hall in 1991

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Typeset in Times by Ellis Horwood Limited

Alai~.

BrItish Lihrary Cataloguing-in-Publication Data

Charles Food hiochemistry. -l Ellis Horwood series in food science and technology) I. Title II. Linden. Guy III. Series 574.19

ISBN 978-1-4613-5883-1 ISBN 978-1-4615-2119-8 (eBook) DOI 10.1007/978-1-4615-2119-8

Lihrary of Congress Cataloging-in- Publication Data

Alais, Charles. [Abarcge de hiochimic alimentairc, English I Food biochemistry I C. Alais, G. Linden: translator, A. Whitehead. p. cm. - (Ellis Horwood series in food science and technology) Translation of: Abrege de biochimie alimentaire. I neludes bihliographieal rderences and index.

I. Food - Composition. ' Biochemistry. I. Linden, G. II. Series. TX545A4213 1991 nM-dc20 91-23024

CIP

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Table of contents

PREFACE ............................................. 9

PART 1- THE CONSTITUENTS OF FOODSTUFFS

1 GENERAL OBSERVATIONS ON THE COMPOSITION OF FOODSTUFFS ...................................... 13 I. Analytical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 II. Nutritional values .................................. 16

2 SIMPLE CARBOHYDRATES AND DERIVED PRODUCTS ........... 18 I. Structure and isomerism .............................. 18 II. Pentoses ........................................ 22 III. Hexoses ........................................ 22 IV. Atypical monosaccharides ............................ 26 V. Sugar alcohols .................................... 26 VI. Sugar linkage ..................................... 29 VII. Glucose disaccharides ............................... 29 VIII. Sucrose ........................................ 30 IX. Lactose ........................................ 32 X. Plant oligosaccharides derived from sucrose ................. 33 XI. Animaloligosaccharides .............................. 34 XII. Glycosides ...................................... 35

3 POLySACCHARIDES ................................... 38 I. General remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 II. Starches and glycogen ............................... 39 III. Starch hydrolysis ................................. .41 IV. Inulin ........................................ .42 V. Cellulose ...................................... .43 VI. Hydrocolloids and gelling agents ....................... .45 VII. Gums ......................................... 46

6 Table of contents

VIII. Pectins ........................................ .47 IX. Substances from marine algae ......................... .48 X. Glucosaminoglycans (or mucopolysaccharides) ............... 50 XI. Polysaccharides and the gelling process .................... 51

4 LIPIDS ............................................ . 53 I. General remarks ................................... 53 II. Fatty acids ...................................... 54 III. Physical properties of fatty acids ........................ 55 IV. Unsaturated fatty acids .............................. 58 V. Glycerides ...................................... 61 VI. Phospholipids .................................... 63 VII. Waxes ......................................... 64 VIII. Liposoluble, carotenoids and sterols ...................... 65 IX. Lipid oxidation ................................... 67

5 PROTEINS .......................................... 71 I. Amino acids ..................................... 71 II. Pep tides and proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 III. Primary structure and polymorphism ..................... 75 IV. Spatial structure and denaturation ....................... 76 V. Protein-water relationship ............................ 79 VI. Scleroproteins .................................... 81 VII. Functional properties of proteins ........................ 83 VIII. Proteolysis ...................................... 84 IX. Non-enzymatic browning - the Maillard reaction ............. 86

6 MINERALS .......................................... 90 I. Important points .................................. 90 II. Major elements ................................... 90 III. Trace elements .................................... 93 IV. Biological activity of mineral elements .................... 93

7 WATER ............................................ 95 I. Properties of water in foods ........................... 95 II. Water activity and modification af foods .................. 101

8 VIT AMINS ......................................... 104 I. General observations ............................... 104 II. Stability of vitamins ............................... 104

9 PIGMENTS ......................................... 111 I. The chlorophylls .................................. 111

Table of contents 7

II. Flavonoids and their derivatives ........................ 113 III. Other compounds ...................... ; .......... 114

PART Il-BIOCHEMISTRY OF THE PRINCIPAL FOODS

10 CEREALS - BREAD .................................. 119 I. General observations on cereals ........................ 119 II. Cereal grains - composition .......................... 121 III. Reserve proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 IV. Wheat gliadins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 V. Glutenins ...................................... 124 VI. Biochemical polymorphism of plant proteins ............... 125 VII. Bread ........................................ 125 VIII. Edible pastas .................................... 129

11 PROTEINS FROM LEGUMINOUS PLANTS AND SINGLE-CELL ORGANISMS ....................................... 130 I. Composition .................................... 130 II. Soya bean - constituents ............................ 131 III. Constituents of soya bean flour ........................ 133 IV. Soya globulins ................................... 134 V. Field beans ..................................... 135 VI. Leaf protein .................................... 135 VII. Texturization of plant proteins ......................... 136 VIII. Proteins from single-cell organisms ...................... 137

12 FERMENTED DRINKS ................................. 140 I. The fermentations ................................ 140 II. Wine ......................................... 141 III. Beer ......................................... 143 IV. Cloudiness in beer ................................ 145 V. Bitter substances present in hops ....................... 146 VI. Alcohol- biological aspects .......................... 147

13 MILK AND DAIRY PRODUCTS ........................... 148 I. General points ................................... 148 II. Lactose and oligosaccharides .......................... 150 III. Lipids - chemical aspects ........................... 151 IV. Lipids - globular state ............................. 155 V. Butter-making ................................... 156 VI. Nitrogenous substances - the caseins .................... 156 VII. Whey proteins ................................... 162 VIII. Casein association - micelles ......................... 164

8 Table of contents

IX. Coagulation of milk ............................... 165 X. Principles of cheese-making .......................... 166 XI. Dairy products (other than butter and cheese) .............. 168

14 MEAT AND BLOOD PRODUCTS .......................... 174 I. Muscle proteins .................................. 174 II. Stroma proteins - collagen and tenderness of meat. .......... 174 III. Sarcoplasmic proteins - myoglobin, meat colour ............ 177 IV. Myofibrillar proteins - contraction ..................... 180 V. Rigor mortis and conditioning ........................ 181 VI. Cured meats - salami, sausage ........................ 183 VII. Food gelatine .................................... 186 VIII. Blood ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

15 EGGS ......................................... " ... 193 I. Hens' eggs - the shell .............................. 193 II. Egg yolk ....................................... 194 III. Egg white ...................................... 197 IV. New egg products ................................. 200 V. Functional properties of egg products . . . . . . . . . . . . . . . . . . . . 200

16 OILS AND FATS ..................................... 202 I. General observations ............................... 202 II. Modification treatments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 III. Oils.......................................... 204 IV. Margarines and cooking fats . . . . . . . . . . . . . . . . . . . . . . . . . . 206

17 ADDITIVES ........................................ 209 I. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 II. Technological additives ............................. 210 III. Flavour additives ................................. 213 IV. Additives of nutritional value ......................... 218

INDEX ............................................... 219

Preface

What I have said will go to prove that true science is the, one which teaches us to increase our satisfaction by drawing out the best from nature's productions.

M. Henri Braconnot Nancy, 4th April 1830

(Extract from the Note on Casein and Milk, Annales de Chimie et de Physique (1830) 43, 351.)

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The main objective of this work is to provide a biochemical approach for students of food science and technology. It may also be useful to biologists generally and to biochemists in particular in providing a source of reference to help resolve some of their problems. Finally, professionals in the food industry will find here detailed information on aspects of biotechnology.

With the continuing development of teaching in this field in the mainstream courses of Instituts Universitaires de Technologiet, Universities and Grandes Ecoles:j: in France, the need for an Abn?ge (Essential Guide) has become urgent. Students have to refer to various specialist works, which are considerable in number, expensive and often out of date.

The authors were faced with the task of selecting material and presenting it in such a way that the finished book would be reduced to a size in keeping with the spirit of the Abrege collection.

This book concentrates on biochemistry, as such; microbiological aspects have not been taken into account. General ideas about the mechanism of life will not be considered here; it will be assumed that the reader knows about them; but it must be said that our book will cover some of the metabolic aspects.

t Universities concentrating on technological subjects. :\: Specialist schools with competitive national entry.

10 Preface

For easy reference the subject matter has been divided into two sections. The first section comprises a review of the constitution of food substances. The second section outlines the biochemical properties of main human foods in this part of the world.