不同冻结方式对带鱼品质影响的研究

为了提高贮藏期带鱼的品质,本文采用液氮冻结、平板冻结、冰柜直接冻结处理鲜带鱼,以贮藏期间的理化指标、感官品质和扫描电镜为指标,研究不同冻结方式对带鱼品质的影响。结果表明:三种冻结方式处理的带鱼TVB-N、TBA值均随时间的增加而增加,液氮冻结处理的带鱼TVB-N、TBA值的增加最慢,至贮藏70 d时,三种冻结方式处理的带鱼TVB-N分别达到0.12 mg/g、0.18mg/g、0.20 mg/g,说明液氮冻结能够有效的延缓TVB-N、TBA值的增加;三种冻结方式处理下的带鱼的盐溶性蛋白、持水性、感官品质、白度值均呈现下降的趋势;Ca2+-ATPase酶活和总巯基含量呈现先增加后降低趋势,其中冰柜直接冻结方式处理组下降速度最快,液氮冻结方式处理下降最慢,说明液氮冻结能够更好的抑制蛋白质的冷冻变性,保持带鱼的良好的品质;微观扫描电镜观察发现液氮冻结对带鱼肌肉纤维的损伤最小。

Effects of Different Freezing Methods on the Quality of Trichiurus haumela

Three different freezing methods, the liquid nitrogen frozen, plate frozen, ordinary refrigerator frozen, were used to pretreat the fresh Trichiurus haumela. Physiochemical indexes, sensory indexes and scanning electron microscopy (SEM) were determined to investigate the effect of different frozen methods on the quality of Trichiurus haumela during frozen periods.Results showed that TVB - N and TBA values of Trichiurus haumela increased with the storage time increased among all the three methods. Those values of samples treated with ordinary refrigerator frozen showed the fasterst increasing rate, while TVB-N and TBA values of samples pretreated by liquid nitrogen increased rather slowly, After stored for 70 days, the TVB - N values of the samples treated with the three methods reached 0.12 mg/g, 0.18 mg/g and 0.20 mg/100 g, respectively by liquid nitrogen frozen, plate frozen and ordinary refrigerator frozen, thus suggesting that liquid nitrogen frozen could keep the quality of Trichiurus haumela better than the conventional methods. The soluble protein, water holding capacity, sensory quality and whiteness value of Trichiurus haumela declined. while the Ca2 + - ATPase enzyme activity and the total sulfydryl content increased first, and then decreased during storage. But the samples treated by liquid nitrogen showed great advantage compared with the conventional frozen because it could inhibit the protein denaturation. Microscopic scanning electron microscopy profiles revealed that myofibril of Trichiurus haumela slightly damaged by the liquid nitrogen.