本文研究了添加0%、1%、3%、5%水溶性大豆多糖（SSPS）的鳙鱼鱼糜经-18℃冻藏12周后肌原纤维蛋白溶解度、Ca2+-ATP酶活性、总巯基含量的变化, 并结合荧光光谱、拉曼光谱分析蛋白质结构的变化. 结果表明, 鳙鱼鱼糜肌原纤维蛋白溶解度、Ca2+-ATP酶活性、总巯基含量在前四周下降迅速, 其后下降速度减缓, 呈两段下降趋势, 而SSPS的加入可以缓解这些指标的下降, 添加量为5%时效果最好. 冻藏12周鱼糜的荧光光谱和拉曼光谱表明SSPS可以减少鱼糜肌原纤维蛋白芳香族氨基酸残基（色氨酸, 酪氨酸）的暴露, 降低ɑ-螺旋含量的减少, 阻止二硫键构象由扭曲-扭曲-反式向扭曲-扭曲-扭曲的变化, 添加量为5%时效果最好. 研究表明SSPS可有效地减缓鳙鱼鱼糜在冻藏期间发生蛋白质变性, 提高其冻藏品质,是一种非常有潜力的新型蛋白抗冻剂.

In this paper the changes of solubility, Ca2+-ATPase activity and total sulfhydryl content of myofibrillar protein of Aristichthys nobilis surimi were investigated after they were frozen with 0%, 1%, 3%, 5% soluble soybean polysaccharides (SSPS) for 12 weeks at -18oC. Myofibrillar protein structure changes during frozen storage were also analyzed based on the Fluorescence spectra and Raman Spectra. Results showed that the protein solubility, Ca2+-ATPase activity as well as total sulfhydryl content of frozen Aristichthys nobilis surimi presented two phases of dropping trend. They decreased sharply during the previous four weeks, but to a lower extent during the subsequent eight weeks. The addition of SSPS could reduce these changes to some extent and the best effect was obtained by 5% SSPS. The Fluorescence spectra and Raman spectra of 12-week frozen surimi also indicated that SSPS could prevent the exposure of aromatic amino acid residues, such as tryptophan and tyrosine, to a polar microenvironment on the myofibrillar protein surface. SSPS could also reduce the decrease of ɑ-helix content and prevent the conformational changes of disulfide bonds from gauche-gauche-trans (g-g-t) to gauche-gauche-gauche (g-g-g). The best effect was obtained by 5% SSPS. The results showed that SSPS could effectively mitigate the myofibrillar protein denaturation of Aristichthys nobilis surimi and improve their quality during the 12-week frozen storage. Therefore SSPS is promising as a new protein cryoprotectant.