Effect of oxidized lipids stored under different temperatures on muscle protein oxidation in Sichuan-style sausages during ripening

This study was conceived to research muscle protein oxidation under the influence of four different degrees of oxidized lipids during the ripening of Sichuan-style sausages. Lipids were stored at different temperatures to obtain different oxidation degrees. To elucidate the relationship between lipid oxidation and protein oxidation, the indicators of lipid oxidation, protein oxidation and protein degradation were analysed. During ripening, the carbonyl, SH, SS and free amino acid contents changed significantly. The carbonyl and SS contents increased first in all samples, then decreased, whereas the SH content showed the opposite results. These results showed a positive correlation between protein oxidation and lipid oxidation. Lipids with a higher oxidation degree induced a stronger oxidation reaction to protein. Meanwhile, the results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the influence of lipid oxidation on myofibrillar proteins was much more intense than on sarcoplasmic proteins.