浸渍式快速冷冻液的优化及冻结技术对脆肉鲩品质的影响

Optimization of immersion solution for quick freezing and the effect of freezing technology on the quality characteristics of crisp grass carp

为优化浸渍快速冻结的冷冻液配方,以乙醇、丙二醇、甜菜碱和氯化钠组成冷冻液,运用Box-Behnken实验设计原理进行实验设计,探讨冷冻液的最佳配比。并用此最佳冷冻液(-35℃)对脆肉鲩进行研究,比较-18℃冻结、直接浸渍冻结、间接浸渍冻结对脆肉鲩品质的影响。结果表明:以占冷冻液总质量分数计,由20%乙醇、10%丙二醇、7%甜菜碱和10%氯化钠和水组成的冷冻液,冻结点可达-66.10℃。采用-18℃冻结的样品与两种浸渍冻结的样品相比较,前者肌原纤维蛋白含量和总巯基含量低于后者,并且Ca2+-ATPase活性的损失高于后者。综合各项指标说明浸渍冻结利于减少蛋白的变性。

An immersion solution for quick freezing was using ethanol,propanediol,betaine and sodium chloride. A Box-Behnken experimental design was used to explore optimal immersion solution formulation. The optimal immersion solution was used to study on crisp grass carp,compared the influence of immersion and chilling freezing and traditional -18℃ on the quality changes of crisp grass carp. A freezing point of -66.10℃ was observed for an aqueous immersion solution containing,on a total dipping solution weight basis,20% ethanol, 10% propanediol,7% betaine and 10% sodium chloride,respectively. Compared with the other two freezing processing,crisp grass carp frozen in -18℃ had lower content of myofibrillar protein and total-SH,more reduced Ca^＋-ATPase activity. The results of physicochemical and textural characteristics indicated that immersion and chilling freezing could assist to reduce the denaturation of fish protein.