三疣梭子蟹(Portunustrituberculatus)冻藏过程中肌肉蛋白质生化特性的变化

Changes in the biochemical properties of muscle protein of swimming crab(Portunus trituberculatus) during frozen storage

以三疣梭子蟹肌肉基本营养成分、蛋白质组成、肌原纤维蛋白含量、Ca^(2+)-ATPase活性、总巯基含量、二硫键含量以及肌原纤维蛋白的SDS-PAGE分析作为指标,研究了三疣梭子蟹在不同冻藏温度下肌肉蛋白质生化特征的变化。结果表明,三疣梭子蟹是典型的高蛋白食品;随着冻藏时间的延长,水溶性蛋白含量先增加后减少,盐溶性蛋白和不溶性蛋白含量逐渐减少,碱溶性蛋白含量逐渐增加;肌原纤维蛋白含量、Ca^(2+)-ATPase活性、总巯基含量随着冻藏时间的延长,均呈现下降趋势,而二硫键含量则呈上升趋势,且–20℃和–40℃两组之间差异显著(P<0.05)。SDS-PAGE分析结果表明,组成肌原纤维蛋白的各种蛋白质均有不同程度降解,且–20℃比–40℃组降解更明显。因此,–40℃冻藏对梭子蟹肌肉蛋白质生化特性的影响较小。

This study analyzed the changes in the biochemical characteristics of muscle protein during frozen storageat–20℃or–40℃based on nutrient composition,protein composition,myofibrillar protein content,Ca2+-ATPase activity,sulfhydryl group content,disulfide bond content,and SDS-PAGE analysis of myofibrillar protein of swimmingcrab.Results showed that the muscle of the swimming crab was a typical food with a high protein content.With extension of the duration of frozen storage,the water-soluble protein content increased and then decreased,thesalt-soluble protein and-insoluble protein contents decreased,and the content of alkaline-soluble protein increasedgradually.Myofibrillar protein content,Ca2+-ATPase activity,and sulfhydryl group content decreased with prolongationof the duration of frozen storage,whereas the disulfide bond content showed an increasing trend,with a significantdifference between the two groups at–20℃and–40℃(p<0.05).The SDS-PAGE results showed that alltypes of proteins of myofibrillar protein were degraded to different degrees,and the degradation was more apparentat?20℃than at?40℃.Therefore,frozen storage at–40℃has minimal effect on the biochemical characteristicsof muscle protein.