The Maillard Reaction In Food Processing Human Nutrition And Physiology

Chemical changes that occur in foods during processing and storage are manifold and might be both desirable and undesirable in nature. While many of the processes are carried out intentionally, there are also certain unwanted changes that naturally occur in food and might have to be controlled. Therefore, efforts are made to devise processing technologies in which desirable attributes of foods are retained and their deleterious ef fects are minimized. While proteins, lipids and carbohydrates are the main nutrients of food that are affected by processing, it is their interaction with one another, as well as in volvement oflow-molecular-weight constituents that affects their flavor, color and overall acceptability. Thus, generation of aroma via thermal processing and bioconversion is of utmost importance in food preparation. Furthermore, processing operations must be opti mized in order to eliminate or reduce the content of antinutrients that are present in foods and retain their bioactive components. Therefore, while novel processing technologies such as freezing, irradiation, microwaving, high pressure treatment and fermentation might be employed, control process conditions in a manner that both the desirable sensory attributes and wholesomeness of foods are safeguarded is essential. Obviously, method ologies should also be established to quantitate the changes that occur in foods as a result of processing. This volume was developed from contributions provided by a group of internation ally-recognized lead scientists.

Food processing is now the biggest industry in the UK and in many other countries. It is also rapidly changing from what was essentially a craft industry, batch processing relatively small amounts of product, to a very highly automated one with continuously operating high speed production lines. In addition, consumers have developed a greater expectation for consistently high standard products and coupled this with demands for such things as a more natural flavour, lower fat etc. The need for an increased knowledge of the scientific principles behind food processing has never been greater. Within the industry itself, increased automation, company diversification and amalgamations etc. have meant that those working in it have often to change their field of operation. Whereas twenty years ago, someone starting work in one branch of the food industry could expect, if he or she so desired, to work there all their working lives, this is now seldom the case. This means that a basic knowledge of the principles behind food processing is necessary both for the student at university or college, and for those already in the industry. It is hoped, therefore, that this book will appeal to both, and prove to be a useful reference over a wide range of food processing.

A variety of processing methods are used to make foods edible; to pennit storage; to alter texture and flavor; to sterilize and pasteurize food; and to destroy microorganisms and other toxins. These methods include baking, broiling, cooking, freezing, frying, and roasting. Many such efforts have both beneficial and harmful effects. It is a paradox of nature that the processing of foods can improve nutrition, quality, safety, and taste, and yet occasionally lead to the formation of anti-nutritional and toxic compounds. These multifaceted consequences of food processing arise from molecular interactions among nutrients with each other and with other food ingredients. Since beneficial and adverse effects of food processing are of increasing importance to food science, nutrition, and human health, and since many of the compounds formed have been shown to be potent carcinogens and growth inhibitors in animals, I organized a symposium broadly concerned with the nutritional and toxicological consequences of food processing. The symposium was sponsored by the American Institute of Nutrition (AIN) -Federation of American Societies for Experimental Biology (FASEB) for its annual meeting in Washington, D.C., April 1-5, 1990. Invited speakers were asked to develop at least one of the following topics: 1. Nutrient-nonnutrient interactions between amino acids, proteins, carbohydrates, lipids, minerals, vitamins, tannins, fiber, natural toxicants, etc. 2. Effects of radiation. 3. Thermally induced formation of dietary mutagens, antimutagens, carcinogens, anticarcinogens, antioxidants, and growth inhibitors. 4. Effects of pH on nutritional value and safety.

Developments in the understanding of food protein structure, behaviour and applications continue apace. Many of these have, in the past decade, been reported and evaluated in the series 'Developments in Food Pro teins' , comprising seven volumes, with a total of 55 chapters. The time has now come to re-assess many of the topics reviewed in that series and to add certain others. However, instead of assembling, some what at random, food protein topics from quite disparate fields in indi vidual volumes, we have decided to bring together homogeneous groups of topics, each representing a specific sector of the subject. Under the general theme of 'Progress in Food Proteins' the first of these groups covers 'Biochemistry' . Readers will note that, though six of the topics reviewed in this volume are new, five of them have already featured in 'Developments in Food Proteins'. These last are in active research fields in which new develop ments have been of special significance. In this sense, therefore, they are welcome updates.