鼓风速冻对海鲈鱼肌原纤维蛋白理化性质和结构的影响

Effects of quick blast freezing on the physicochemical properties and structure of myofibrin in sea bass

以-20℃冰箱冷冻为对照,采用-20℃和-40℃低温鼓风速冻处理海鲈鱼片,分析冷冻方式对鱼肉肌原纤维蛋白理化性质和结构的影响.结果表明,冷冻导致海鲈鱼肉肌原纤维蛋白溶解度和总巯基含量降低,粒径增加,但鼓风速冻效果优于冰箱冷冻(P<0.05).拉曼分析结果表明,冰箱处理组α-螺旋含量低于鼓风速冻组(P<0.05),说明速冻对蛋白质二级结构的影响较小.冷冻会引起鱼肉肌原纤维蛋白内源荧光强度降低,但鼓风速冻处理的鱼肉肌原纤维蛋白荧光强度高于传统冰箱冷冻处理组,且随着速冻温度降低,肌原纤维蛋白荧光强度升高.DSC数据表明,-40℃低温速冻后鱼肉蛋白质变性温度高于-20℃冰箱冷冻和-20℃鼓风速冻,同温度鼓风速冻后鱼肉蛋白质的热稳定性高于传统冰箱冷冻处理.

-20℃refrigerator freezing was used as control,the effects of freezing methods on the physicochemical properties and structure of myofibrin of sea bass fillets were analyzed by quick blast freezing treatment at-20℃and-40℃respectively.The results showed that the solubility of myofibrin and the content of total sulfhydryl group of sea bass myofibrin were decreased,and the particle size increased after freezing treatment,respectively,but the effect of blast quick freezing treatment was better than that of refrigerator freezing treatment(P<0.05).Results of Raman analysis showed that theα-helix content of refrigerator treatment group was lower than that of blast quick freezing group(P<0.05),indicating that quick freezing had little effect on protein secondary structure.The endogenous fluorescence intensity of fish myofibrin decreased after freezing,but the fluorescence intensity of fish myofibrin treated by blast freezing was higher than that treated by conventional refrigerator freezing,and the fluorescence intensity of fish myofibrin increased with the decrease of freezing temperature.DSC data showed that the denaturation temperature of fish protein after-40℃blast freezing treatment was higher than that of-20℃blast freezing treatment and-20℃refrigerator freezing treatment,and the thermal stability of fish protein after-20℃blast freezing treatment was higher than that of traditional refrigerator.