The susceptibility of meats from different animal species (beef quadriceps femoris, porcine longissimus dorsi, and chicken pectoralis major) to undergo protein oxidation during frozen storage (20 weeks/–18 °C) was studied through the analysis of novel oxidation markers. Frozen storage induced protein carbonylation (α-aminoadipic and γ-glutamic semialdehydes), carboxylation (α-aminoadipic acid), and formation of Schiff bases in meat from the three species. Major rates of protein and lipid oxidation products [thiobarbituric-acid-reactive substances (TBARS) and hexanal] were found in beef patties. Among the endogenous factors having a potential influence on the susceptibility of meat to undergo protein oxidation, heme iron seemed to play a major role. The present study illustrates the severe chemical modifications induced by oxidative stress during frozen storage of ground meat and provides original insight into the underlying mechanisms and factors.
Keywords: Protein oxidation; carbonylation; α-aminoadipic acid; Schiff bases; meat animals; frozen storage; lipid oxidation