微冻贮藏过程中能量代谢酶活性和蛋白质氧化降解对鲈鱼质构特性的影响

为了研究微冻贮藏过程中鲈鱼质构特性与能量代谢酶和蛋白质氧化之间的关系,分析了3种不同处理方式(空气包装处理、真空包装处理、茶多酚结合真空包装处理)对微冻(-2℃)贮藏过程中鲈鱼的剪切力、组织结构、差式扫描量热曲线、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、巯基含量和3种能量代谢酶(乳酸脱氢酶、Ca2+-ATP酶、Mg2+-ATP酶)活力的影响。结果表明:随微冻贮藏时间的延长,3种不同处理方式下鲈鱼的剪切力、总巯基含量和能量代谢酶活力均显著下降(P0.05),而茶多酚结合真空包装处理组各指标显著高于其他两个处理组(P0.05),表明茶多酚对微冻贮藏过程中鲈鱼品质有保护作用。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳图谱和差示扫描量热曲线结果表明,在微冻条件下贮藏21 d鲈鱼肌球蛋白发生轻微变性;经过相关性分析得出,3种能量代谢酶活力均与总巯基含量呈显著正相关(P0.01,r=0.99),表明ATP酶和乳酸脱氢酶活力与肌原纤维蛋白的降解密切关,总巯基含量和ATP酶活力、剪切力之间也呈现极显著正相关性(P0.01,r=0.92),表明鲈鱼肌原纤维蛋白氧化会导致质构的劣化。

Effects of Energy Metabolism-Related Enzyme Activities and Protein Oxidation on Texture Properties of Perch (Micropterus salmoides) during Superchilled Storage

In order to study the relationship between the texture traits of perch and energy metabolism-related enzymes and protein oxidation during superchilled storage, we investigated the influence of three different packaging treatments (air packaging, vacuum packaging, and tea polyphenols combined with vacuum packaging) on the shear stress, microstructure, differential scanning calorimetric (DSC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), total sulfhydryl content and energy metabolism-related enzyme (lactate dehydrogenase, Ca2＋-ATPase, and Mg2＋-ATPase) activities of perch during superchilled storage at ?2 ℃. The results showed that for all three groups, the shearing force, total thiol content and energy metabolism-related enzyme activities were significantly decreased with prolonged storage (P < 0.05), and a significant increase in these parameters was recorded for the third group compared with the two other groups (P < 0.05), indicating that tea polyphenols could preserve the quality of perch during superchilled storage. The SDS-PAGE and DSC analysis showed that myosin was slightly denaturated during superchilled storage for 21 days. The activities of three energy metabolism-related enzymes were positively correlated with the content of sulfhydryl groups (P < 0.05, r = 0.99), indicating that ATPase and lactate dehydrogenase activities are closely related to the degradation of myofibrillar protein, and there was also a significant positive correlation between the total content of thiol and ATPase activity and shear force (P < 0.01, r = 0.92), suggesting that myofibrillar protein oxidation could cause texture deterioration in perch.