摘要
研究了在没有外加碱的pH渐变条件下,用枯草杆菌碱性蛋白酶(Alcalase2.4L,酶活力2.4AU/g)和黑曲霉酸性蛋白酶(酶活力3000u/g)双酶协同水解从大豆蛋白制备寡肽(10个氨基酸以下的肽)水解物的可行性.考察了单酶单因素水解条件、双酶加入方式对大豆蛋白降解率和蛋白质水解度的影响,并在此基础上通过正交试验进一步优化出双酶一次性投料方案下水解大豆蛋白的最佳条件:水解温度为60℃,碱性蛋白酶加入量为每g蛋白15μL,酸性蛋白酶加入量为6%,底物浓度为40g/L,水解时间为18h.在上述最佳条件下,大豆蛋白的降解率可达76%,蛋白质的水解度可达26%,水解物中相对分子质量小于1350的寡肽达到了66%.结果表明,在不外加碱的条件下,采用双酶协同水解方法能够显著提高大豆蛋白降解率以及蛋白质水解度.
The feasibility of making oligopeptides from the synergetic hydrolysis of soybean protein by Bacillus subtilis alkaline protease (2.4 AU/g)and Aspergillus niger acidic protease (3 000 u/g) under the condition of the spontaneous drop of broth pH has been studied. On the basis of finding the optimum conditions for both enzymes via mono-factor investigations and selecting an one-time-all-enzymes feeding manner, orthogonal test is carried out to further optimize the synergetic hydrolysis conditions which are determined as follows: hydrolyzing temperature 60 ℃,ratio of alkaline protease/substrate 15 μL/g, mass ratio of acidic protease and substrate 6%, concentration of substrate 40 g/L, total hydrolysis time 18 h. Under such conditions the degradation percentage of the soybean protein can reach 76%, while the hydrolysis degree of protein (i.e., the ratio of the peptide bonds cleavaged/total peptide bonds in protein) can reach 26%, peptides of molecular weight below (1 350) can reach 66%. The results indicate that the cooperation of acidic protease with alkaline protease clearly favors the degradation of soybean protein and the preparation of soybean protein oligopeptides, and thus permitting the hydrolysis to be performed without using additional base.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2004年第1期51-55,共5页
Journal of Dalian University of Technology
基金
辽宁省自然科学基金资助项目(001074).
关键词
大豆蛋白
寡肽
酸性蛋白酶
碱性蛋白酶
soybean protein
oligopeptide
acid protease
alkaline protease
