Autoxidation of unsaturated lipids

CHAN H w s (1987) Autoxidation of Unsaturated Lipids, London, Academic Press. 

POKORNY j (1987) Major factors affecting the autoxidation of lipids , in Chan El W S, Autoxidation of unsaturated lipids , London, Academic Press, 141-206. 

Chan HWS (ed) (1987) Autoxidation of unsaturated lipids. Academic, London... 

Since the early 1960s, the understanding of autoxidation of unsaturated lipids and antioxidative mechanisms have advanced significantly as a result of development of... 

Antioxidant preservative by terminating free radicals formed during autoxidation of unsaturated lipids. It also possesses antimicrobial activity as a phenolic compound. 

The majority of compounds that are subject to autoxidation are unsaturated substances or highly condensed polymers, and the target of ROS is commonly the diene fimctionality—or double bonds. Autoxidation of unsaturated lipids is a good model to demonstrate this mechanism. The initial reaction between molecular oxygen and a polyunsaturated fatty acid (PUFA) occurs as RH -l- O2 —> ROOH, which involves the movement of a double bond as well as the insertion... 

Pokorny, J. 1987. Major Factors Affecting the Autoxidation of Lipids, in Autoxidation of Unsaturated Lipids. Chan, H.W.-S. (ed.) London, UK Academic Press Ltd., pp. 140-233. 

Grosch W. (1987) Reactions of hydroperoxides. Products of low molecular weight. In Autoxidation of Unsaturated Lipids. Academic Press, London, pp. 95-138. 

The second pathologic finding, ceroid pigment, a product of autoxidation of unsaturated lipids, has been reported in the smooth muscle of the stomach, intestine, bronchial wall, and bladder of children djdng with cystic fibrosis of the pancreas, particularly if they were over 2 years of age (Blanc et al., 1958 Kerner and Goldbloom, 1960). It was less frequent in infants who died with biliary atresia, presumably because of their earlier death. These lesions, which also have been described in adults with the malabsorption syndrome (Pappenheimer and Victor, 1946 Braunstein, 1961) bear a close resemblance to the findings in the vitamin E-deficient animal where the amount of ceroid deposition can be correlated with the level of unsaturated fatty acids in the diet (Mason et al., 1946). 

During lipid oxidation, the primary oxidation products that are formed by the autoxidation of unsaturated lipids are hydroperoxides, which have little or no direct impact on the sensory properties of foods. However, hydroperoxides are degraded to produce additional radicals which further accelerates the oxidation process and produce secondary oxidation products such as aldehydes, ketones, acids and alcohols, of which some are volatiles with very low sensory thresholds and have potentially significant impact on the sensory properties namely odor and flavor [2, 3]. Sensory analysis of food samples are performed by a panel of semi to highly trained personnel under specific quarantined conditions. Any chemical method used to determine lipid oxidation in food must be closely correlated with a sensory panel because the human nose is the most appropriate detector to monitor the odorants resulting from oxidative and non-oxidative degradation processes. The results obtained from sensory analyses provide the closest approximation to the consumers approach. Sensory analyses of smell and taste has been developed in many studies of edible fats and oils and for fatty food quality estimation [1, 4, 5]. 

Chan, H.W.-S. and Coxon, D.T. Lipid hydroperoxides, in Autoxidation of Unsaturated Lipids, pp. 30-31 (1987) (edited by H.W.-S. Chan), Academic Press, London. 

Pokomy, J. Major factors affecting the autoxidation of lipids. In Autoxidation of Unsaturated Lipids, Chan, H.W.S., Ed., Academic Press London, 1987 pp. 159-206. 

Carry out all operations (homogenisation, extraction, etc.) in a nitrogen atmosphere, o as to prevent autoxidation of unsaturated lipids. 

Lipid derived radicals (L, LO-, and LOO ) are produced during the initiation and propagation stages of the autoxidation of unsaturated lipids. The source of the primary radical in lipid autoxidation is still an open question. However, the reaction may be initiated by cleavage of preformed lipid hydroperoxides (LOOH) by transition metal ions, i ch form lipid alkoxy 1 radicals (LO ), or by metal-catalyzed cleavage ofhydrogen peroxide (HjOj), which forms hydroiQ l radicals ( OH, Fenton... 

Chan, H.W.-S. (Ed.) Autoxidation of unsaturated lipids. Academic Press London. 1987 Choe, E., Min, D.B. Chemistry and reactions of reactive oygen species in foods. Crit. Rev. Food Sci. Nutr. 46, 1 (2006)... 

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