预冻后冻藏温度对金鲳鱼品质的影响

Effect of Frozen Storage Temperature on the Quality of Pre-frozen Golden Pomfret

为探究预冻后冻藏温度对金鲳鱼品质变化的影响,将真空包装金鲳鱼整鱼在-40℃下预冻24 h,分别于-20、-40℃下冻藏24周,测定冻藏过程中品质、蛋白氧化、脂肪氧化及肌肉组织微观结构的变化。结果表明,整个冻藏期间金鲳鱼整鱼均保持良好的感官品质,但-40℃冻藏金鲳鱼整鱼感官品质更好;-20℃冻藏金鲳鱼肉离心损失率上升更快;随着冻藏时间延长,冻藏金鲳鱼肉肌原纤维蛋白的总巯基含量与内源荧光强度逐渐降低、二硫键含量和羰基含量逐渐增加、金鲳鱼肉的硫代巴比妥酸反应物值也逐渐上升、表面疏水性先增加后下降,但不同冻藏温度之间没有显著差异;冻藏24周金鲳鱼肉的肌纤维缝隙和断裂程度增大,但不同冻藏温度之间的组织微观结构无显著差异。综上所述,经过-40℃预冻处理后,相较于-20℃,-40℃冻藏不能有效延缓金鲳鱼整鱼品质劣变。因此从节能角度考虑,经预冻后金鲳鱼整鱼冻藏温度应选择-20℃。

To investigate the effect of frozen storage temperature on the quality changes of pre-frozen golden pomfret,vacuum-packaged wholefish were pre-frozen at–40℃for 24 h,and stored for 24 weeks at–20 or–40℃.During storage,changes in quality indicators,protein oxidation,fat oxidation,and muscle microstructure were measured.The results showed that golden pomfret maintained good sensory quality throughout the entire storage period,with better sensory quality being observed when stored at–40℃.The centrifugal loss rate of golden pomfret stored at–20℃increased more rapidly.As the frozen storage time extended,the total sulfhydryl content and intrinsicfluorescence intensity of myofibrillar proteins in frozen golden pomfret meat gradually decreased,while disulfide bond and carbonyl contents increased.The thiobarbituric acid value of golden pomfret meat also increased gradually.Surface hydrophobicity increased initially and then decreased,but there was no significant difference between different storage temperatures.After 24 weeks of freezing,the gap between and fracture degree of musclefibers in golden pomfret meat increased,but there was no significant difference in muscle microstructure between different storage temperatures.In conclusion,after pre-freezing treatment at–40℃,storage at–40℃did not effectively delay the quality deterioration of whole golden pomfret compared to–20℃.Therefore,considering energy efficiency,–20℃is recommended as freezing storage temperature for whole golden pomfret after pre-freezing treatment.