Does protein oxidation affect proteolysis in low sodium Chinese traditional bacon processing?

This work investigated protein oxidation, proteolysis and their interrelationship during the manufacturing process of low-sodium Chinese traditional bacon. The bacons were prepared by four different salting treatments: substituting sodium chloride (NaCl) using 0, 30, 50, and 70% of potassium chloride (KCl). Protein oxidation was evaluated by total carbonylation, thiol oxidation, and tryptophan fluorescence changes. Proteolysis was detected by non-protein nitrogen, free amino acid, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the manufacturing process of low-sodium Chinese bacon, protein oxidation and protein proteolysis were simultaneously observed. Electrophoresis pattern showed that 70% substitution of KCl could promote proteolysis, meanwhile, protein oxidation possibly facilitated by 70% KCl replacement resulted in reduced tryptophan fluorescence and increased total carbonyl content. Additionally, a good correlation between protein oxidation and proteolysis was observed.