低水量蛋白酶酶解大豆浓缩蛋白工艺研究

大豆浓缩蛋白(soybean protein concentrate,SPC)的酶解多用于改善SPC的功能特性,且酶解过程以高水量液态酶解为主。为了降低酶解的生产成本,提高SPC在饲料中的应用效果及利用率,本试验在较低水量条件下,以不同的料水比、酶添加量、pH值、酶解温度为工艺参数,采用两种不同的蛋白酶对SPC进行酶解,考察水解度和酸溶蛋白含量等指标,研究降低水量对酶解效果的影响,以期在控制加水量的同时,实现提高酸溶蛋白含量及降解抗原蛋白的目的。试验结果表明,当料水比为1∶1.5(g∶mL)、酶解时间为6 h时,蛋白酶A的最适条件为酶添加量3%、pH 9.0、50℃;蛋白酶B的最适条件为酶添加量0.8%、pH 6.5、50℃。采用两种蛋白酶的最适酶解条件酶解SPC,当料水比从1∶0.5增加到1∶2时,水解度和酸溶蛋白含量均随着水量的增加而增加,但增幅逐渐变缓。当料水比为1∶0.5时,蛋白酶A酶解SPC,水解度为3.7%,酸溶蛋白含量为7.4%;蛋白酶B酶解SPC,水解度为4.0%,酸溶蛋白含量为6.7%;SDS-PAGE电泳结果表明,此时SPC中抗原蛋白条带即可实现明显降解。因此,在低水量酶解条件下,可以显著降解SPC的抗原蛋白,提高水解度,从而改善其营养价值。

Study on Enzymatic Hydrolysis of Soybean Protein Concentrate by Protease with Low Water Content

The enzymatic hydrolysis of soybean protein concentrate(SPC)was mostly used to improve the functional characteristics of SPC.The enzymatic hydrolysis process are mainly liquid enzymatic hydrolysis with high water content.In order to reduce the production cost of enzymatic hydrolysis,improve the application effect in feed and feed utilization,this paper studied the effect using reducing water on enzymatic effect of two kinds of proteases,changing the parameters of ratio of material to water,enzyme amount,pH,and temperature,the evaluation indexs were degree of hydrolysis and acid soluble protein content,in the hope of the high content of small peptide and the degradation of antigen protein can be achieved when the enzymatic hydrolysis process with low water content.The results showed that when the ratio of material to water was 1∶1.5(g∶mL)and enzymolysis time was 6 h,the optimum conditions were:addition of 3%,pH 9.0,enzymolysis temperature 50℃for proteases A and addition of 0.8%,pH 6.5,enzymolysis temperature 50℃for proteases B.When the ratio of material to water increased from 1∶0.5 to 1∶2,the degree of hydrolysis and acid soluble protein content of SPC increased with the increase of water quantity,but the rate of increase gradually slowed down.When the ratio of material to water was 1∶0.5,the degree of hydrolysis was 3.7%and acid soluble protein content was 7.4%for protease A,the degree of hydrolysis was 4.0%and acid soluble protein content was 6.7%for protease B,at this moment,SDS-PAGE electrophoretic results showed that the antigenic protein bands in SPC could be significantly degraded.It can be seen that the antigenic protein of SPC can be significantly eliminated by enzymatic hydrolysis,under the low water content and the degree of hydrolysis of SPC can be increased,so as to improve its nutritional value.