水溶性大豆多糖对鳙鱼鱼糜蛋白冷冻变性及结构的影响  

Effect of Soluble Soybean Polysaccharides on Protein Denaturation and Structure of Frozen Aristichthys nobilis Surimi

作　　者：高文宏[1] 黄扬萍 曾新安[1] GAO Wenhong;HUANG Yangping;ZENG Xin’an(School of Food Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China)

机构地区：[1]华南理工大学食品科学与工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2018年第11期16-22,共7页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省科技计划项目(2016A020210008;2015A030312001);国家自然科学基金资助项目(21576099;21376094)~~

摘　　要：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、Ca^(2+)-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、Ca^(2+)-ATP酶活性、总巯基含量在冻藏的前4周迅速下降,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,且添加量为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α-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,且添加量为5%时效果最好.说明SSPS可有效地减缓鳙鱼鱼糜在冻藏期间的蛋白质变性,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, Ca^2+-ATPase activity and total sulfhydryl content of myofibrillar protein in Aristichthys nobilis surimi were investigated after they were frozen with 0%, 1%, 3% and 5% soluble soybean polysaccharides(SSPS) for 12 weeks at-18 ℃. Then, the myofibrillar protein structure change during the frozen storage was analyzed based on the fluorescence spectra and Raman spectra. The results show that the protein solubility, Ca^2+-ATPase activity and total sulfhydryl content of frozen Aristichthys nobilis surimi all present two phases of dropping trend, namely first a sharp decrease during the previous four weeks and then a relatively lower decrease during the subsequent eight weeks. The addition of SSPS can reduce these changes to some extent and the best effect is obtained at a SSPS dosage of 5%.Moreover, the fluorescence spectra and Raman spectra of 12-week frozen surimi indicate that SSPS can prevent the exposure of such aromatic amino acid residues as tryptophan and tyrosine to a polar microenvironment on the myofibrillar protein surface;and that SSPS can also reduce the decrease of α-helix content and prevent the conformational changes of disulfide bonds from gauche-gauche-trans to gauche-gauche-gauche, especially at a SSPS dosage of 5%. It is thus concluded that SSPS can effectively mitigate the myofibrillar protein denaturation of Aristichthys nobilis surimi and improve the frozen surimi’s quality during the frozen storage. Therefore, SSPS is promising as a new protein cryoprotectant.

关 键 词：水溶性大豆多糖 鳙鱼鱼糜 肌原纤维蛋白 冷冻变性 拉曼光谱 荧光光谱 

分 类 号：TS254.4[轻工技术与工程—水产品加工及贮藏工程]