Research in the field of the Maillard reaction has developed rapidly in recent years as a result of not only the application of improved analytical techniques, but also of the realisation that the Maillard reaction plays an important role in some human diseases and in the ageing process. The Maillard Reaction: Chemistry, Biochemistry, and Implications provides a comprehensive treatise on the Maillard reaction. This single-author volume covers all aspects of the Maillard reaction in a uniform, co-ordinated, and up-to-date manner. The book encompasses: the chemistry of non-enzymic browning; recent advances; colour formation in non-enzymic browning; flavour and off-flavour formation in non-enzymic browning; toxicological aspects; nutritional aspects; other physiological aspects; other consequences of technological significance; implications for other fields; non-enzymic browning due mainly to ascorbic acid; caramelisation; inhibition of non-enzymic browning in foods; and inhibition of the Maillard reaction in vivo. The Maillard Reaction: Chemistry, Biochemistry, and Implications will be welcomed as an important publication for both new and experienced researchers who are involved in solving the mysteries and complexities of Maillard chemistry and biochemistry. It will also appeal to students, university lecturers, and researchers in a variety of fields, including food science, nutrition, biochemistry, medicine, pharmacology, toxicology, and soil science. A readable, concise history and overview of the field, an excellent laboratory resource, a "must read" for new students of the reaction, and a valuable resource for more senior scientists. ― Journal of the American Chemical Society, Vol.127, No.41, 2005 (John W Baynes) A valuable source of reference for years to come. If you are interested in the Maillard reaction, or are involved in food chemistry or chemical pathology, this book is a must. ― Chemistry & Industry, Issue 16, 15 August 2005 (Peter Belton) The Maillard Reaction Chemistry, Biochemistry and Implications By Harry Nursten The Royal Society of Chemistry Copyright © 2005 The Royal Society of Chemistry All rights reserved. ISBN: 978-0-85404-964-6 Contents Abbreviations, x, Chapter 1 Introduction, 1, Chapter 2 The Chemistry of Nonenzymic Browning, 5, Chapter 3 Recent Advances, 31, Chapter 4 Colour Formation in Nonenzymic Browning, 52, Chapter 5 Flavour and Off-Flavour Formation in Nonenzymic Browning, 62, Chapter 6 Toxicological and Protective Aspects, 90, Chapter 7 Nutritional Aspects, 101, Chapter 8 Other Physiological Aspects, 105, Chapter 9 Other Consequences of Technological Significance, 124, Chapter 10 Implications for other Fields, 143, Chapter 11 Nonenzymic Browning Mainly Due to Ascorbic Acid, 146, Chapter 12 Caramelisation, 150, Chapter 13 Inhibition of Nonenzymic Browning in Foods, 152, Chapter 14 Inhibition of the Maillard Reaction in Vivo, 161, Bibliography, 172, Subject Index, 208, CHAPTER 1 Introduction 1 Categorisation There are two main types of mechanism by which browning of food occurs, depending on whether the process is mediated by enzymes or not. The division is not precise and, in a specific case, it is usually difficult to rule out one or the other mechanism, unless conditions are such, for instance, during heat processing, that enzymes would have been inactivated. Under such conditions, only nonenzymic browning can occur. Nonenzymic browning itself is subdivided roughly (again because there is an overlap) into three types of reactions. The first, called the Maillard reaction, occurs between a carbonyl compound, which here is usually a reducing sugar, and an amine, which here is usually an amino acid, a peptide, or a protein. The second is caramelisation, a reaction where the sugars react on their own, but normally requires more drastic conditions. (Some discuss this under the heading of 'active' aldehydes.) The third is ascorbic acid oxidation. The last, although it need not involve any enzyme at all, is nearest to enzymic browning, since it often does involve ascorbic acid oxidase, which, however, does not affect the phenols, which are the normal substrate in enzymic browning, but may involve other enzymes, e.g., laccase or peroxidase. Here, much attention will be given to the Maillard reaction, since one can consider caramelisation and ascorbic acid oxidation as special cases of it. Also, the Maillard reaction is the one of physiological significance. 2 Historical: Louis-Camille Maillard Maillard (1878–1936) qualified in medicine from the University of Nancy in 1903, where he joined the Chemical Division of the School of Medicine. In 1914, he became the head of a biological group in the Chemical Laboratory, University of Paris, and, in 1919, he was appointed as the Professor of Biological and Medical Chemistry at the University of Algiers. Maillard was interested in Emil Fischer's synthesis of peptides, which he thought