| Abstract
| - The oxidation of methyl linoleate (LMe) in the presence of bovine serum albumin (BSA) was studiedto analyze both the processes involved when lipid oxidation occurs in the presence of proteins andthe relative progression of the several reactions implicated. The disappearance of LMe, the formationof primary and secondary lipid oxidation products, the loss of essential amino acids, and the productionof oxidized lipid/amino acid reaction products (OLAARPs) were studied as a function of incubationtime. During the first steps of lipid oxidation, LMe was converted quantitatively to methyl linoleatehydroperoxides, which were very rapidly degraded to either secondary products of lipid oxidation orOLAARPs. No significant differences were identified in the major lipid oxidation products formed inincubations with or without proteins, indicating that mechanisms for formation of these compoundsare similar in both cases. In addition, no significant differences were observed between the time-courses of formation of secondary oxidation products and OLAARPs, suggesting that hydroperoxidedecomposition and OLAARP formation occur simultaneously when the lipid oxidation process takesplace in the presence of proteins. Furthermore, OLAARP formation seems to be an unavoidableprocess that should be considered as a last step in the lipid peroxidation process. Keywords: Amino acid losses; carbonyl−amine reactions; lipid oxidation; nonenzymatic browning;oxidized lipid/protein reactions; protein damage; pyrrole amino acids
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