牦牛乳酪蛋白胨生产工艺优化

Optimization of production process of yak milk casein peptone

中文关键词:  牦牛乳酪蛋白  碱性蛋白酶  胰蛋白酶  水解度  

英文关键词:yak milk casein protein  alcalase  trypsin  degree of hydrolysis

中文摘要:

      目的 探究以牦牛乳酪蛋白为原料, 优化酪蛋白胨的生产工艺。方法 将碱性蛋白酶和胰蛋白酶两种酶组合水解牦牛乳酪蛋白, 在单因素试验基础上, 根据Box-Behnken的中心组合试验设计原理, 采用四因素三水平的响应面分析法, 以水解度为响应值作响应面和等高线, 得出组合酶水解牦牛乳酪蛋白的最佳工艺条件, 再经过酸沉、中和、最后喷雾干燥得到牦牛乳酪蛋白胨产品。结果 单因素结果显示, 组合酶浓度增大, 酪蛋白水解度呈上升趋势, 酶添加量高于2.5%时, 水解度上升趋势变缓。温度和pH的升高, 使水解度呈先上升再下降的趋势。牦牛乳酪蛋白水解度在底物浓度5%时达到最大, 底物浓度会阻碍酶对切割位点的作用, 导致蛋白转化率降低。响应面结果显示, 组合酶添加量2.6%(碱性蛋白酶:胰蛋白酶=4:1)、水解时间160 min、水解pH 7.0、底物浓度5%、水解温度55 ℃时, 水解度最好, 为23.63%。结论 本研究优化了以牦牛乳酪蛋白制备蛋白胨的生产工艺, 为牦牛乳酪蛋白的进一步开发利用提供支持。

英文摘要:

      Objective To optimize the production process of casein peptone with yak milk casein as raw material. Methods The combination of alkaline protease and trypsin was used to hydrolyze yak milk casein. On the basis of single factor experiment, according to the principle of Box-Behnken central combination test design, the response surface analysis method of four factors and three levels was adopted, and the degree of hydrolysis was used as the response value. The response surface and contour line were used to obtain the optimal process conditions for the hydrolysis of yak milk casein by the combined enzyme, and then the yak milk casein peptone product was obtained by acid precipitation, neutralization and finally spray drying. Results The results of single factor showed that the degree of hydrolysis of casein increased with the increase of enzyme concentration. When the amount of enzyme added was higher than 2.5%, the degree of hydrolysis increased slowly. With the increase of temperature and pH, the degree of hydrolysis increased first and then decreased. The degree of hydrolysis of yak milk casein reached the maximum when the substrate concentration was 5%, and the substrate concentration would hinder the effect of the enzyme on the cutting site, resulting in a decrease in protein conversion. The results of response surface showed that the degree of hydrolysis was the best when the amount of combined enzyme was 2.6% (alkaline protease:trypsin=4:1), the hydrolysis time was 160 min, the hydrolysis pH was 7.0, the substrate concentration was 5%, and the hydrolysis temperature was 55 °C, which was 23.63%. Conclusion This study optimize the production process of peptone from yak milk casein, and provided support for the further development and utilization of yak milk casein.