羟自由基氧化对鲤鱼肌原纤维蛋白乳化性及凝胶性的影响

研究羟自由基( ·OH)氧化对鲤鱼肌原纤维蛋白乳化性、凝胶质地及凝胶微观结构的影响。采用由FeCl3、抗坏血酸浓度和不同浓度(0～20mmol/L)H2O2组成的 ·OH氧化体系，对鲤鱼肌原纤维蛋白分别氧化1、3、5h后测定蛋白的乳化活力及乳化稳定性，利用质构仪、扫描电镜对凝胶特性和微观结构进行研究。结果表明：蛋白质氧化会引起鲤鱼肌原纤维蛋白乳化性及凝胶性发生改变，表现在乳化活力和乳化稳定性下降，凝胶弹性、硬度、保水性及白度有不同程度的下降，凝胶微观结构遭到破坏。这些蛋白氧化引起的变化说明，蛋白质氧化对鲤鱼肌原纤维蛋白乳化性及凝胶性能有较大的破坏作用。

Effect of Hydroxyl Radical Oxidation on Emulsifying and Gel Properties of Common Carp(Cyprinus carpio) Myofibrillar Protein

The objective of this study was to investigate emulsifying and gel properties of common carp myofibrillar protein treated by hydroxyl radical-generating systems (HRGS) containing 0.1 mmol/L ferric chloride, 0.1 mmol/L ascorbic acid and 0－20 mmol/L hydrogen peroxide for 1, 3 h and 5 h, respectively. The results revealed that oxidative stress had a destructive effect on emulsifying and gel properties of fish myofibrillar protein. The emulsion activity index (EAI) and emulsion stability index (ESI), gel texture parameters (gel springiness and hardness), gel whiteness and gel WHC of fish myofibrillar protein revealed a significant decrease (P＜0.05) due to oxidation and the microstructure of heat-induced myofibrillar protein gels was also damaged. These oxidation-induced functional changes reveal high susceptibility of common carp myofibrillar protein to oxidative stress.