Schieberle Food Chemistry 4th revised and extended ed. With 481 Figures, 923 Formulas and 634 Tables 123 Professor Dr. Hans-Dieter Belitz † Professor em. Werner Grosch Ehem.
Professor für Lebensmittelchemie an der Technischen Universität München Ehem. Direktorder Deutschen Forschungsanstalt für Lebensmittelchemie München Lichtenbergstraße 85748 Garching Professor Dr. Peter Schieberle Ordinarius für Lebensmittelchemie an der Technischen Universität München Leiter des Instituts für Lebensmittelchemie an der Technischen Universität München Direktor der Deutschen Forschungsanstalt für Lebensmittelchemie München Lichtenbergstraße 85748 Garching ISBN 978-3-540-69933-0 e-ISBN 978-3-540-69934-7 DOI 10.1007/978-3-540-69934-7 Library of Congress Control Number: 2008931197 © Springer-Verlag Berlin Heidelberg 2009 This work is subject to copyright. All rights are reserved, whether the whole or part of the mate- rial is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks.
Dupli- cation of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Production: le-tex publishing services oHG, Leipzig Typesetting: le-tex publishing services oHG, Leipzig Cover design: KünkelLopka GmbH, Heidelberg, Germany Printed on acid-free paper 987654321 springer.com Preface Preface to the First German Edition The very rapid development of food chemistry and technology over the last two decades, which is due to a remarkable increase in the analytical and manufacturing possibilities, makes the complete lack of a comprehensive, teaching or reference text particularly noticeable. It is hoped that this textbook of food chemistry will help to fill this gap. In writing this volume we were able to draw on our experience from the lectures which we have given, covering various scientific subjects, over the past fifteen years at the Technical University of Munich. Since a separate treatment of the important food constituents (proteins, lipids, car- bohydrates, flavor compounds, etc.) and of the important food groups (milk, meat, eggs, cereals, fruits, vegetables, etc.) has proved successful in our lectures, the sub- ject matter is also organized in the same way in this book.
Compounds which are found only in particular foods are discussed where they play a distinctive role while food additives and contaminants are treated in their own chapters. The physical and chemical properties of the important constituents of foods are discussed in detail where these form the basis for understanding ei- ther the reactions which occur, or can be expected to occur, during the production, processing, storage and handling of foods or the methods used in analyzing them. An attempt has also been made to clarify the relationship between the structure and properties at the level of individual food constituents and at the level of the whole food system. The book focuses on the chemistry of foodstuffs and does not consider national or international food regulations.
We have also omitted a broader discussion of aspects related to the nutritional value, the processing and the toxicology of foods. All of these are an essential part of the training of a food chemist but, because of the extent of the subject matter and the consequent specialization, must today be the subject of separate books. Nevertheless, for all important foods we have included brief discussions of manufacturing processes and their parameters since these are closely related to the chemical reactions occurring in foods. Commodity and production data of importance to food chemists are mainly given in tabular form.
Each chapter includes some references which are not intended to form an exhaustive list. No preference or judgement should be inferred from the choice of references; they are given simply to encourage further reading. Additional literature of a more general nature is given at the end of the book. This book is primarily aimed both at students of food and general chemistry but also at those students of other disciplines who are required or choose to study food chemistry as a supplementary subject.
We also hope that this comprehensive text vi Preface will prove useful to both food chemists and chemists who have completed their formal education. We thank sincerely Mrs. Lynen and Mrs. Wüst for their help during the prepara- tion of the manuscript and its proofreading.
We are very grateful to Springer Verlag for their consideration of our wishes and for the agreeable cooperation. Grosch Preface to the Fourth English Edition The fourth edition of the “Food Chemistry” textbook is a translation of the sixth German edition of this textbook. It follows a general concept as detailed in the preface to the first edition given below. All chapters have been carefully checked and updated with respect to the latest developments, if required.
Comprehensive changes have been made in Chapters 9 (Contaminants), 18 (Phenolic Compounds), 20 (Alcoholic Beverages) and 21 (Tea, Cocoa). The following topics were newly added: • the detection of BSE and D-amino acids, • the formation and occurrence of acrylamide and furan, • compounds having a cooling effect, • technologically important milk enzymes, • the lipoproteins of egg yolk, • the structure of the muscle and meat aging, • food allergies, • the baking process, • the reactivity of oxygen species in foods, • phytosterols, • glycemic index, • the composition of aromas was extended: odorants (pineapple, raw and cooked mutton, black tea, cocoa powder, whisky) and taste compounds (black tea, roasted cocoa, coffee drink). The production data for the year 2006 were taken from the FAO via Internet. The volume of the book was not changed during the revision as some existing chapters were shortened.
We are very grateful to Dr. Margaret Burghagen for translating the manuscript. It was our pleasure to collaborate with her. We would also like to thank Prof.
Jürgen Weder and Dr. Rolf Kieffer for several valuable recommendations. We are also grateful to Sabine Bijewitz and Rita Jauker for assistance in completing the manuscript, and Christel Hoffmann for help with the literature and the index. Schieberle Contents 0 Water .2 Liquid Water and Ice .3 Effect on Storage Life .2 Water Activity as an Indicator .3 Phase Transition of Foods Containing Water.
7 1 Amino Acids, Peptides, Proteins .2 Classification, Discovery and Occurrence .2 Discovery and Occurrence .2 Configuration and Optical Activity .1 Esterification of Carboxyl Groups .2 Reactions of Amino Groups .2 Alkylation and Arylation .3 Carbamoyl and Thiocarbamoyl Derivatives .4 Reactions with Carbonyl Compounds .3 Reactions Involving Other Functional Groups .3 Aspartic and Glutamic Acids .4 Serine and Threonine .5 Cysteine and Cystine .4 Reactions of Amino Acids at Higher Temperatures .2 Mutagenic Heterocyclic Compounds .5 Synthetic Amino Acids Utilized for Increasing the Biological Value of Food (Food Fortification) .1 General Remarks, Nomenclature .2 Carnosine, Anserine and Balenine .1 Amino Acid Sequence .1 Amino Acid Composition, Subunits .5 Derivation of Amino Acid Sequence from the Nucleotide Sequence of the Coding Gene .1 Extended Peptide Chains .4 Super-Secondary Structures .3 Tertiary and Quaternary Structures .3 Solubility, Hydration and Swelling Power .4 Foam Formation and Foam Stabilization .1 Reactions Which Retain the Positive Charge .2 Reactions Resulting in a Loss of Positive Charge .3 Reactions Resulting in a Negative Charge .3 Glutamic and Aspartic Acid Residues .4 Cystine Residue (cf.5 Cysteine Residue (cf.11 Reactions Involved in Food Processing .5 Enzyme-Catalyzed Reactions .6 Chemical and Enzymatic Reactions of Interest to Food Processing .3 Redox Reactions Involving Cysteine and Cystine .2 General Remarks, Isolation and Nomenclature .4 Isolation and Purification .5 Multiple Forms of Enzymes .1 Nicotinamide Adenine Dinucleotide .1 Magnesium, Calcium and Zinc .2 Iron, Copper and Molybdenum .4 Theory of Enzyme Catalysis .1 Active Site Localization .2 “Lock and Key” Hypothesis .3 Induced-fit Model .2 Reasons for Catalytic Activity .1 Steric Effects – Orientation Effects .2 Structural Complementarity to Transition State .4 General Acid–Base Catalysis .5 Kinetics of Enzyme-Catalyzed Reactions .1 Effect of Substrate Concentration .1 Single-Substrate Reactions .1 Michaelis–Menten Equation .2 Determination of Km and V .2 Two-Substrate Reactions .1 Order of Substrate Binding .2 Rate Equations for a Two-Substrate Reaction .2 Effect of Inhibitors .2 Non-Competitive Inhibition .3 Effect of pH on Enzyme Activity .4 Influence of Temperature .1 Time Dependence of Effects .2 Temperature Dependence of Effects .5 Influence of Pressure .6 Influence of Water .2 End-Point Method .2 Determination of Enzyme Activity .4 Polymerase Chain Reaction .1 Principle of PCR .1 Addition of Soybean .2 Genetically Modified Soybeans .3 Genetically Modified Tomatoes .7 Enzyme Utilization in the Food Industry .1 Technical Enzyme Preparations .3 Cross-Linked Enzymes .10 Cellulases and Hemicellulases. 155 xii Contents 3 Lipids .1 Nomenclature and Classification .1 Saturated Fatty Acids .2 Unsaturated Fatty Acids .3 Substituted Fatty Acids .2 Crystalline Structure, Melting Points .1 Methylation of Carboxyl Groups .2 Reactions of Unsaturated Fatty Acids .1 Halogen Addition Reactions .2 Transformation of Isolene-Type Fatty Acids to Conjugated Fatty Acids .3 Formation of a π -Complex with Ag+ Ions .4 Biosynthesis of Unsaturated Fatty Acids .1 Nomenclature, Classification, Calorific Value .2 Mono- and Diacylglycerols (MG, DG) .4 Phospho- and Glycolipids .1 Extraction, Removal of Nonlipids .2 Separation and Identification of Classes of Components .3 Analysis of Lipid Components .2 Involvement of Lipids in the Formation of Biological Membranes .6 Diol Lipids, Higher Alcohols, Waxes and Cutin .2 Higher Alcohols and Derivatives .7 Changes in Acyl Lipids of Food .2 Polar-Lipid Hydrolases .2 Peroxidation of Unsaturated Acyl Lipids .1 Fundamental Steps of Autoxidation .4 Initiation of a Radical Chain Reaction .6 Heavy Metal Ions .2 Lipoxygenase: Occurrence and Properties .3 Enzymatic Degradation of Hydroperoxides .4 Hydroperoxide–Protein Interactions .1 Products Formed from Hydroperoxides .2 Lipid–Protein Complexes .4 Decomposition of Amino Acids .3 Inhibition of Lipid Peroxidation .2 Antioxidants in Food .4 Fat or Oil Heating (Deep Frying) .1 Autoxidation of Saturated Acyl Lipids .6 Microbial Degradation of Acyl Lipids to Methyl Ketones .2 Steroids of Animal Food .2 Methyl- and Dimethylsterols .3 Tocopherols and Tocotrienols .1 Chemical Structure, Occurrence .4 Precursors of Aroma Compounds .5 Use of Carotenoids in Food Processing .1 Structure and Nomenclature .1 Hygroscopicity and Solubility .2 Optical Rotation, Mutarotation .4 Chemical Reactions and Derivatives .1 Reduction to Sugar Alcohols .2 Oxidation to Aldonic, Dicarboxylic and Uronic Acids .3 Reactions in the Presence of Acids and Alkalis .1 Reactions in Strongly Acidic Media .2 Reactions in Strongly Alkaline Solution .4 Reactions with Amino Compounds (Maillard Reaction) .1 Initial Phase of the Maillard Reaction .2 Formation of Deoxyosones .3 Secondary Products of 3-Deoxyosones .4 Secondary Products of 1-Deoxyosones .5 Secondary Products of 4-Deoxyosones .8 Formation of Colored Compounds .10 Inhibition of the Maillard Reaction .5 Reactions with Hydroxy Compounds (O-Glycosides) .8 Cleavage of Glycols .1 Structure and Nomenclature .2 Properties and Reactions .1 Extended or Stretched, Ribbon-Type Conformation .2 Hollow Helix-Type Conformation .3 Crumpled-Type Conformation .4 Loosely-Jointed Conformation .5 Conformations of Heteroglycans .2 Perfectly Linear Polysaccharides .4 Linearly Branched Polysaccharides .5 Polysaccharides with Carboxyl Groups .6 Polysaccharides with Strongly Acidic Groups .1 Derivatization with Neutral Substituents .2 Derivatization with Acidic Substituents .10 Locust Bean Gum .12 Arabinogalactan from Larch .2 Structure and Properties of Starch Granules .3 Structure and Properties of Amylose .4 Structure and Properties of Amylopectin .1 Mechanically Damaged Starches .5 Thin-Boiling Starch .8 Cross-Linked Starches .1 Alkyl Cellulose, Hydroxyalkyl Cellulose .22 Inulin and Oligofructose .5 Enzymatic Degradation of Polysaccharides .4 α -Dextrin Endo-1,6-α -glucosidase (Pullulanase) .6 Analysis of Polysaccharides .2 Impact Compounds of Natural Aromas .5 Off-Flavors, Food Taints .1 Aroma Extract Dilution Analysis (AEDA) .2 Headspace GC Olfactometry .6 Quantitative Analysis, Aroma Values .1 Isotopic Dilution Analysis (IDA) .7 Aroma Model, Omission Experiments .3 Individual Aroma Compounds .4 Thiols, Thioethers, Di- and Trisulfides .1 Carbonyl Compounds, Alcohols .5 Volatile Sulfur Compounds .4 Interactions with Other Food Constituents .5 Natural and Synthetic Flavorings .1 Raw Materials for Essences .5 Synthetic Natural Aroma Compounds .6 Synthetic Aroma Compounds .