Interactions of oxidized lipids with protein Part XVI. Interactions of oxidized ethyl linoleate with collagen

Abstract

The reaction of ethyl linoleate with collagen proceeded at 60 degrees C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decomposition. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fasted in the stage of maximum hydroperoxide content, and both ether-insoluble and ether-soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour-active carbonylic oxidation products with protein.

Effect of cysteine and ribose on the volatile thermal degradation products of a triglyceride and three phospholipids

“…The reaction between cdrbonyl compounds and ethanolamine has also been shown to give browning (Suyama and Adachi 1979;Husain et af 1986). It has been suggested that the ethanolamine group may react with either the hydroperoxides themselves or with aldehydes derived from them to give unstable Schiff bases which react further to give brown pigments by polycondensation reactions with aldehydes (Pokorny et al 1973(Pokorny et al , 1990Tai rt al 1974).…”

ALTERATIONS OF MUSCLE PROTEIN FUNCTIONALITY BY OXIDATIVE AND ANTIOXIDATIVE PROCESSES1

“…Numerous studies in model systems have shown that oxidizing lipids, peroxides, and certain metal ions cause protein polymerization or fragmentation, insolubilization, amino acid destruction, and formation of protein free radicals and protein-lipid complexes (Roubal and Tappel 1966;Kanner and Karel 1976;Schaich 1980;FUMS et al 1982;Pokorny et al 1990;Meucci et al 1991;Stadtman and Oliver 1991;Uchida et al 1992). These physicochemical modifications could lead to alterations in protein functionality which can be described in terms of protein-protein interaction such as aggregation and gelation, protein-lipid interaction such as emulsification, and protein-water interaction such as viscosity and solubility, resulting in adverse changes in texture and palatability of affected muscle foods. Controlled oxidative processes can be potentially beneficial in processing of some food products.…”

Chemical, physical, and functional properties of oxidized turkey white muscle myofibrillar proteins

“…Site-specific metal-catalyzed oxidation results in loss of enzyme activity and solubility, increases in carbonyl groups and fluorescence, changes in amino acid composition, and increased proteolytic susceptibility (Levine etal., 1990;Meuccietal., 1991). Protein oxidation can also couple with lipid oxidation, resulting in loss of enzyme activity and solubility and formation of protein complexes and nonenzymic browning products (Kanner and Karel, 1976; Funes et al, 1982;Pokorny et al, 1990).…”