海藻糖、乳酸钠对冻藏鳙鱼鱼糜蛋白抗冻效果的影响

以凝胶强度、盐溶性蛋白含量、Ca~(2+)-ATPase活性、总巯基、表面疏水性为指标并结合DSC分析(差示扫描量热分析),研究了海藻糖、乳酸钠在8%(w/w)水平上对鳙鱼鱼糜蛋白在-18℃冻藏24周的抗冻效果,并将其抗冻效果与传统商业抗冻剂(4%蔗糖+4%山梨糖醇)进行了对比。结果表明,海藻糖、乳酸钠的加入能较好地抑制冻藏鳙鱼鱼糜蛋白的冷冻变性,表现在这2种物质加入后,冻藏鳙鱼鱼糜的凝胶能力得到较好的维持,盐溶性蛋白含量、Ca~(2+)-ATPase活性和巯基含量的下降及表面疏水性的增加也得到很好的抑制,2种物质的抗冻效果比传统商业抗冻剂具有明显的优势。DSC分析表明,抗冻剂的添加可能改变了鳙鱼鱼糜肌球蛋白的结构,使其变得更稳定,从而表现出较好的冻藏稳定性。海藻糖、乳酸钠都属于低甜度、低热值物质,因此在鱼糜加工业中有望成为传统商业抗冻剂的替代物。

Cryoprotective Effects of Trehalose and Sodium Lactate on Bighead (Aristichthys nobilis) Surimi during Frozen Storage

The cryoprotective effects of trehalose and sodium lactate at level of 8%(w/w)in bighead surimi were studied in comparison with a conventional cryoprotectant(4 % sucrose+4 % sorbitol)during ex- tended storage at—18℃for up to 24 weeks using gel strength,salt extractable protein(SEP),Ca~(2+)—AT- Pase activity,total sulfhydryl content,surface hydrophobicity as indicators together with differential scan- ning calorimeter(DSC).The results showed the addition of trehalose and sodium lactate could retard the protein denaturation of frozen bighead surimi as evidenced by the good maintenance of gel-forming ability, lowered decrease in SEP,Ca~(2+)—ATPase activity,total sulfhydryl content as well as the impeded increase in surface hydrophobicity.Their effects were comparable to those of commercial cryoprotectant.DSC indicated the myosin structure of frozen bighead surimi might be strengthened hence had better frozen stability-with the addition of trehalose and sodium lactate.Therefore,trehalose and sodium lactate appeared to be a prom- ising alternative cryoprotectant of the conventional cryoprotectant in surimi industry owing to their low sweetness and calorie.