羊肉火腿加工过程中粗肽抗氧化活性

为明确羊肉火腿加工过程中内源抗氧化肽的抗氧化能力变化，本实验以不同加工时期干腌羊肉火腿为研究对象，利用磷酸盐缓冲液提取粗肽并测定多肽质量分数，对粗肽还原力、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基清除率、2,2’-联氮-二(3-乙基-苯并噻唑-6-磺酸)（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)，ABTS）阳离子自由基清除率、羟自由基清除率、脂质过氧化抑制率进行评价。结果表明：羊肉火腿加工过程中多肽质量分数显著升高，抗氧化活性显著增强，具体表现为加工过程中还原力显著增强（P＜0.05），ABTS阳离子自由基和DPPH自由基清除率总体呈上升趋势，分别在成熟结束期和成熟中期表现出最强抗氧化能力（分别为0.09、0.017 8 mmol/L）；羟自由基清除率总体呈下降趋势，在风干期抗氧化能力达到最大。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果表明，从原料腿到成熟结束期肌肉中蛋白质逐渐发生降解，产生小分子抗氧化肽。本实验为下一步研究羊肉火腿多肽的抗氧化机制提供参考。

Changes in Antioxidant Activity of Crude Peptides from Mutton Ham at Different Processing Stages

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.