[关键词]
[摘要]
采用浸渍冷冻方法探讨了水溶性大豆多糖(SSPS)对鱼糜冷冻效率和蛋白质变性的影响。以新鲜草鱼(Ctenopharyngodon idellus)鱼糜为原料首先进行了SSPS添加量(1%、3%和5%)对鱼糜冻结过程影响的研究,发现添加3% SSPS的鱼糜特征冷冻时间最短,冻藏14 d后肌原纤维蛋白含量最高。然后以冷冻鱼糜肌原纤维蛋白Ca2+-ATPase活性、总巯基含量、活性巯基含量及盐溶性蛋白含量为指标评价冻藏8周期间鱼糜蛋白的变性情况,发现冻藏2周后添加SSPS的鱼糜组的四种评价指标数值均显著高于对照组,其中添加3% SSPS效果最佳。冻藏8周后添加3% SSPS的鱼糜肌原纤维蛋白Ca2+-ATPase活性、总巯基含量、活性巯基含量及盐溶性蛋白含量分别为0.35 μmol (pi)/ [mg (protein)·min]、3.41×10-5 mol/g protein、2.37×10-5 mol/g protein、41.74 mg/g;比对照组分别提高16.87%、14.94%、18.10%、17.35%。结果表明添加SSPS能显著提高鱼糜冷冻效率,延缓冻藏期间鱼糜蛋白质的变性,可作为低甜度鱼糜蛋白抗冻保护剂。
[Key word]
[Abstract]
The effects of water soluble soybean polysaccharide (SSPS) on the freezing efficiency and protein denaturation of surimi were investigated by immersion freezing. The fresh grass carp (Ctenopharyngodon idellus) surimi was used as the raw material. The effect of SSPS addition (1%, 3% and 5%) on the immersion-freezing process of the surimi were firstly studied. Results showed that the characteristic freezing time of the surimi with 3% SSPS was the shortest, and the myofibrillar protein content was the highest after a 14-day frozen storage. Over the 8-week frozen storage, the protein denaturation of surimi was evaluated by measuring the Ca2+-ATPase activity, total sulphydryl content, active sulphydryl content and salt extractable protein content. After 2 weeks of frozen storage, all these four evaluation indices of the treated surimi samples were significantly higher than those of the control surimi, with 3% SSPS providing the greatest cryoprotective effect on protein denaturation. After 8 weeks of frozen storage, the Ca2+-ATPase activity, total sulphydryl content, active sulphydryl content, salt extractable protein content of the myofibrillar protein for the surimi treated with 3% SSPS was 0.35 μmol (pi)/[mg (protein)·min], 3.41×10-5 mol/g protein, 2.37×10-5 mol/g protein, and 41.74 mg/g, respectively, which were increased by 16.87%, 14.94%, 18.10% and 17.35%, respectively, compared to the control surimi. The results indicate that SSPS addition can significantly increase the freezing rate of surimi, mitigate the protein denaturation during frozen storage, thus, SSPS can be used as a low-sweet cryoprotectant for surimi proteins.
[中图分类号]
[基金项目]
广东省省级科技计划项目(2016A020210008;2017B020207001);国家自然科学基金资助项目(21576099)