海藻糖、海藻胶及寡糖对南美白对虾蛋白质冷冻变性的抑制作用

Inhibition of the Freeze-denaturation of Protein in Litopenaeus vannamei by Trehalose, Alginate and Its Oligosaccharides

为探索海藻糖类对于冷冻水产品的抗冻保水效果，以南美白对虾为研究对象，以焦磷酸钠为对照，研究海藻糖、海藻胶及寡糖对南美白对虾蛋白质冷冻变性的抑制效果。结果表明，18℃冻藏6周后，0．5％、1．0％海藻糖和海藻胶寡糖（500-4500Da）处理可显著降低冷冻虾仁解冻汁液流失（5．00-5．54％），其与焦磷酸钠保水效果无显著性差异（5．02～5．48％，p〉O．05）。整个冻藏期内，0．5％、1．0％焦磷酸钠、海藻糖和海藻胶寡糖处理虾仁，肌肉L谊稍有变化但并不显著（p〉0．05），表明该3种物质对冷冻虾仁肌肉明度具有良好保护作用。随着冻藏时间延长，不同处理虾仁肌原纤维蛋白、盐溶性蛋白及Ca2＋-ATPase活性均呈逐渐下降趋势，其中海藻糖、海藻胶寡糖对虾仁蛋白质特性的保护效果，显著优于蒸馏水、焦磷酸钠处理（p〈O．05）。本研究为开发一种安全、高效、适用于冷冻虾仁的无磷保水剂提供参考。

The aim of this work was to evaluate the inhibition of saccharides from seaweed on the freeze-denaturation of protein in Litopenaeus vannameL compared with sodium pyrophosphate as anti-freeze agent. The results indicated that the thawing loss （5.00-5.54%） of shrimp were significantly （p〈0.05） decreased by 0.5% and 1.0% trehalose and alginate oligosaccharides （500-600 Da） treatments atter six weeks storage （-18 ℃）, which showed little significant difference from that by sodium pyrophosphate treatment （5.02-5.48%,p 〉 0.05）. The L＊ values of shrimp were not significantly affected by 0.5%, 1.0% trehalose, alginate and its oligosaccharides （0〉0.05） during the whole storage, which indicated they had good protective effect on the lightness of the shrimp. In addition, the activity of Ca2＋-ATPase, contents of myofibrillar and salt-soluble proteins in shrimp were also decreased in all treated-groups after six weeks storage, while the protective effect on protein by trehalose/alginate oligosaccharides treatments were more significant than the other control groups （p〈0.05）. The study can lay the foundation for developing a kind of safe, natural and harmless non-phosphate additive which is suitable for the frozen shrimp.