Abstract: In this study, dry-cured mutton ham samples at different processing periods were taken in order to clarify the change in the antioxidant activity of endogenous antioxidant peptides during mutton ham processing. Crude peptides were extracted from these samples with phosphate buffer and the peptide content was determined. Subsequently, the antioxidant activity was evaluated by reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS) and hydroxyl radical scavenging capacity, and anti-lipid oxidation activity. The results showed that the peptide content of mutton ham were significantly increased during processing, and so did the antioxidant activity as manifested by a significant increase in reducing activity (P < 0.05) and an overall increase in ABTS cation and DPPH radical scavenging capacity, which reached the maximum values of 0.09 and 0.017 8 mmol/L at the end and the middle stage of maturity, respectively. The hydroxyl radical scavenging capacity showed a downward trend in general, and reached its maximum value during the drying period. Sodium dodecyl sulfate-polyacrylamide gel electrophoresisshowed that proteins in ham muscle were gradually degraded throughout the processing period producing small antioxidant peptides. This study provides reference for future studies on the antioxidant mechanisms of mutton ham peptides.

Key words: mutton ham, protein, crude peptides, antioxidant activity, radical scavenging rate