鲢鱼酶解产物对酵母菌的抗冻保护作用

Cryoprotective effects on yeast of enzymatic hydrolysates from silver carp

优选酵母抗冻剂对改善冷冻面团品质具有重要意义。通过酶法制备了系列鲢鱼酶解产物,分析其基本组成和电泳图谱变化,并考察酶解时间及其浓度对面包酵母冻融过程中存活率的影响。结果表明:面包酵母耐冻性差,1个冻融循环后存活率仅为0.69%;不同酶解时间的鲢鱼酶解产物基本组成相差不大,但酶解15,30min的酶解产物对酵母菌的抗冻保护效果最好;添加4%的30min酶解产物使酵母菌的冷冻存活率提高到90.73%,较8%的甘油提高了42.88%。Tricine-SDS-PAGE分析发现,酶解产物的蛋白条带分布基本相似,但信号随着酶解时间的延长逐渐减弱,其中新增约13kDa的蛋白可能与酶解产物的抗冻保护活性有重要关系。

It is of great significance to improve the quality of frozen dough by selecting yeast antifreeze.The enzymatic hydrolysates from silver carp were prepared by enzymolysis with protamex,and their degree of hydrolysis（%）,composition and electrophoresis profiles were analyzed.Moreover,the effects of enzymolysis time and concentration of enzymatic hydrolysates on the survival rate of yeast were also investigated.The results showed that yeast had poor frost resistance,with only 0.69% of survival rate after the first freezethaw cycle.Components of hydrolysates prepared by enzymolysis for15,30,60,120,240 min were similar,but the products of 15 and30 min had better cryoprotective effect on yeast.By adding enzymatic hydrolysates of 30 min at the concentration of 4%,the survival rate of yeast was increased to 90.73%,which was 42.88% higher than that of the positive control（glycerol）.Tricine-SDS-PAGE analysis indicated protein bands distribution of these hydrolysates were similar,but the band signals were gradually decreases with the prolongation of enzymolysis time,and it was interesting to suggest that the new 13 kDa protein might have important relationship to the cryoprotective activity of enzymatic hydrolysates.