小米分离蛋白提取方法优化及对蛋白组成的影响

针对小米分离蛋白(MPI)提取率不高,蛋白质含量低的问题,本文对比碱法与5种酶法的提取效果,结果三酶复合法(α-淀粉酶/糖化酶/复合纤维素酶)所得MPI提取率、蛋白质含量高.除碱法外,酶法提取对MPI的分子质量分布及二级结构无影响.在6种单因素试验基础上,选取pH值、温度、加酶量及酶解时间为影响MPI蛋白质含量的主要因...

Extraction Method Optimization of Foxtail Millet Isolated Protein and Its Effect on Protein Composition

In view of the difficult extraction and low protein content of millet isolated protein(MPI),this experiment compared the extraction effect of MPI through alkali method and five kinds of enzymatic methods.Under the condition of combingα-amylase/glucoamylase/viscozyme L,the extraction yield and protein content of MPI were high.The molecular weight distribution and secondary structure information of MPI were not affected by different enzymatic methods except alkali method.Based on the results of 6 single-factor experiments,pH,temperature,enzyme addition amount and enzymatic hydrolysis time were selected as the main factors affecting the MPI protein content.Box-Behnken response surface analysis was conducted with the MPI protein content as the response value,and a mathematical regression model was established.Optimum conditions of tri-enzymatic digestion for extracting high protein content MPI were:pH 4.7,enzymatic hydrolysis temperature 48℃,enzymatic addition amount 2.2%and enzymatic hydrolysis time 10 h,under which protein content of MPI was(69.49±0.23)%。