Autoxidation in Food and Biological Systems


Book Description

The material presented in this book deals with basic mechanisms of free radical reactions in autoxidation processes and anitoxidant suppression of autoxidation of foods, biochemical models and biologi cal systems. Autoxidation in foods and corresponding biological effects are usually approached separately although recent mechanistic developments in the biochemistry and free radical chemistry of per oxides and their precursors tend to bring these two fields closer. Apparent ability of antioxidants in diets to reduce the inci dence of cancer has resulted in scrutiny of autoxidized products and their precursors as possibly toxic, mutagenic and carcinogenic agents. Mechanisms of any of these effects have been barely ad dressed. Yet we know now that free radicals, as esoteric as they were only a few decades ago, are being discovered in foods, biochem ical and biological systems and do play a role in the above-mentioned causalities. The purpose of the Workshop and the resulting book was to give a unifying approach towards study of beneficial and deleterious effects of autoxidation, based on rigorous scientific considerations. It is our hope that the material presented in this book will not only provide a review of the "state of the art" of autoxidation and anti oxidants, but also reflect the interaction which occurred during the Workshop between workers using model sytems, and food and biological systems.







Food Antioxidants


Book Description

Antioxidants are present naturally in virtually all food commodities, providing them with a valuable degree of protection against oxidative attack. When food commodities are subjected to processing, such natural antioxidants are often depleted, whether physically, from the nature of the process itself, or by chemical degradation. In conse quence, processed food products usually keep less well than do the commodities from which they originated. Ideally, food producers would like them to keep better. This objective can often be achieved by blending natural products rich in antioxidants with processed foods, or by using well recognised antioxidants as food additives. In order to understand their action, and hence to apply antioxidants intelligently in food product formulation, some knowledge of the mechanisms by which they function is necessary. This is complex and of antioxidative may rely on one or more of several alternative forms intervention. Accordingly, the various mechanisms that may be relevant are discussed in Chapter 1, in each case including the 'intervention' mechanism. When present in, or added to, foods antioxidants are functional in very small quantities, typically, perhaps, at levels of 0·01 % or less.




Atmospheric Oxidation and Antioxidants


Book Description

Volume I reviews current understanding of autoxidation, largely on the basis of the reactions of oxygen with characterised chemicals. From this flows the modern mechanism of antioxidant actions and their application in stabilisation technology.




Oxidation and Antioxidants in Organic Chemistry and Biology


Book Description

Providing a comprehensive review of reactions of oxidation for different classes of organic compounds and polymers, and biological processes mediated by free radicals, Oxidation and Antioxidants in Organic Chemistry and Biology puts the data and bibliographical information you need into one easy-to-use resource. You will find up-to-date information










Lipid Oxidation


Book Description

In this second edition, Edwin Frankel has updated and extended his now well-known book Lipid oxidation which has come to be regarded as the standard work on the subject since the publication of the first edition seven years previously. His main objective is to develop the background necessary for a better understanding of what factors should be considered, and what methods and lipid systems should be employed, to achieve suitable evaluation and control of lipid oxidation in complex foods and biological systems. The oxidation of unsaturated fatty acids is one of the most fundamental reactions in lipid chemistry. When unsaturated lipids are exposed to air, the complex, volatile oxidation compounds that are formed cause rancidity. This decreases the quality of foods that contain natural lipid components as well as foods in which oils are used as ingredients. Furthermore, products of lipid oxidation have been implicated in many vital biological reactions, and evidence has accumulated to show that free radicals and reactive oxygen species participate in tissue injuries and in degenerative disease. Although there have been many significant advances in this challenging field, many important problems remain unsolved. This second edition of Lipid oxidation follows the example of the first edition in offering a summary of the many unsolved problems that need further research. The need to understand lipid oxidation is greater than ever with the increased interest in long-chain polyunsaturated fatty acids, the reformulation of oils to avoid hydrogenation and trans fatty acids, and the enormous attention given to natural phenolic antioxidants, including flavonoids and other phytochemicals.