芬顿氧化体系处理对白斑狗鱼肌原纤维蛋白结构和功能特性的影响

Effect of Fenton Oxidation Treatment on Structural and Functional Properties of Myofibrillar Proteins in Esox lucius Muslce

研究芬顿氧化体系诱导的不同氧化水平(0、1、5、10、20 mmol/L H_(2)O_(2))对白斑狗鱼肌原纤维蛋白结构和功能特性的影响。随着氧化水平的升高,肌原纤维蛋白的羰基和浊度增加、溶解度显著降低(P<0.05)。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析结果显示氧化后的肌原纤维蛋白中产生更多交联和蛋白质聚合。傅里叶变换红外光谱表明,氧化增加了肌原纤维蛋白的结构变化。功能性结果表明,适度氧化处理(1、5 mmol/L)后,肌原纤维蛋白的起泡性较未氧化显著增加1.8倍(P<0.05)、泡沫稳定性几乎不变(保持在90%以上);而肌原纤维蛋白的乳化性能有所下降,其中适度氧化(1、5 mmol/L H_(2)O_(2))影响较小,过度氧化(>10 mmol/L H_(2)O_(2))使乳化性和乳化稳定性明显降低。结果表明,肌原纤维蛋白的适度氧化修饰可提高其起泡能力,提供更好的功能性能。

The present study investigated the effects of different oxidation degrees(0,1,5,10 and 20 mmol/L H_(2)O_(2))induced by a Fenton oxidation system on the functional properties of myofibrillar proteins(MP)from Esox lucius muscle.Increasing oxidation degree caused an increase in carbonyl group content and turbidity and a significant decrease in protein solubility(P<0.05).Sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE)analysis revealed a greater degree of cross-linking and protein aggregation in oxidized MP.Fourier transform infrared spectroscopic(FTIR)analysis suggested that oxidation caused conformational changes in MP.The results of functional characterization indicated that moderate oxidation(1 and 5 mmol/L H_(2)O_(2))substantially increased the foaming capacity of MP by 280%(P<0.05)while having little effect on the emulsifying stability(which remained at above 90%).However,oxidation decreased the emulsifying properties of MP;the influence of moderate oxidation(1 and 5 mmol/L H_(2)O_(2))was small,while excessive oxidation(>10 mmol/L H_(2)O_(2))led to a significant decrease in emulsifying capacity and emulsion stability.These results indicated that mild oxidation could improve the foaming capacity,and provide better functional properties of MP.