[Interactions of fats and proteins in meat. 3. Changes in tryptophan content and available forms of lysine, methionine and cystine].

In experimental models the effect of hydroperoxides of the methyl ester of linoleic acid, and hexanal, on the contents of tryptophan, "available" forms of lysine, methionine and cystine in proteins were analyzed. Conditions typical for technological treatment of meat were simulated. A muscle gel containing large quantities of myofibrillar proteins served as meat substrate. It was found that thermal denaturation and the presence of sodium chloride in the medium stimulate the reactivity of methyl linoleate hydroperoxides and hexanal with proteins. Cystine and lysine demonstrated the highest reactivity with oxidated fats. Addition of hexanal and sodium chloride to the muscle gel caused a distinct decrease in the accessible sulfhydryl groups content.