Interactions of oxidized lipids with protein. Part 17. Effect of protein on the decomposition of products of the lipoxygenase‐catalyzed oxidation in oilseeds

Abstract

AbstractConjugated dienoic lipid hydroperoxides produced by lipoxygenase‐catalyzed oxidation of linoleic and linoleic acids may be decomposed during the reaction either by various enzymic reactions or by the reaction with protein. The interaction of hydroperoxides with protein is very rapid under the experimental conditions, i.e. at room temperature, and in the presence of water, so that 60–70% of the oxidation products become bound to proteins with in 5–20 min. Therefore, the content of free, extractable conjugated dienoic hydroperoxides reaches the maximum within 5–10 min in case of sodium salts of essential fatty acids, their methyl esters or the natural triacylglycerols, respectively. Both the conjugated double bonds and the hydroperoxy groups are eliminated from the reaction medium during the reaction but the formation of lipoprotein complexes is partially reversible. Differences in reactivities were observed in rapeseed, hazelnut or poppyseed mixed proteins, and in various other pure proteins.