摘要
比较了四种酶(胰蛋白酶、胃蛋白酶、Alcalase及自制的枯草芽孢杆菌蛋白酶)对山羊酪蛋白的水解能力。水解度动态测定发现,酶解速度从高到低依次为Alcalase、枯草芽孢杆菌蛋白酶、胰蛋白酶和胃蛋白酶;当40℃水解3h左右,水解度即达到相对稳定的最大值,依次为34.61%、25.28%、19.08%和7.22%。酶解物的SDS-PAGE分析发现,Alcalase、枯草芽孢杆菌蛋白酶能将山羊酪蛋白充分降解成小肽或游离氨基酸,而胰蛋白酶和胃蛋白酶的酶解物中还包含14kDa左右的大肽。山羊酪蛋白对四种酶的敏感程度均高于牛酪蛋白。山羊酪蛋白的胃蛋白酶解物对金黄色葡萄球菌、大肠杆菌有一定抑制作用,枯草芽孢杆菌蛋白酶酶解物具有较强的超氧负离子自由基(O2-·)清除能力,清除率达到50.22%,是相同浓度维生素C(73.73%)的68%,四种酶解物清除O2-·的能力与水解程度呈正相关。
Caprine casein was treated by four different proteases including trypsin, pepsin, alcalase and subtilisin under proper temperature and pH condition. Particularly, subtilisin used was made in the lab by soybean fermentation.The degree of hydrolysis （DH）for all four hydrolysis systems achieved maximum after 3h and were 34.61% ,25.28%, 19.08% and 7.22% for the hydrolysed caprine casein by alcalase, subtilisin, trypsin and pepsin, respectly.We also found that caprine casein was more sensitive to all four proteases than bovine casein.SDS-PAGE was applied to analyze the fractions composing the enzymic hydrolysates which were treated for 3h.lt was demonstrated that the hydrolates by trypsin and pepsin still contained big peptides weighing around 14kDa while alcalase and subtilisin could hydrolyse caprine casein thoroughly,cutting it into small fragments lighter than 14kDa. Moreover,we examined the antimicrobial and antioxidative activity of the four enzymic hydrolysates. The result proved that the peptic hydrolysate of caprine casein inhibit Staphylococcus aureus and Escherichia coil in some extent. Meanwhile, the hydrolysed casein by subtilisin showed great inhibitory effect against O2^- , with a comparable scavenging rate（50.22% ）with vitamin C（73.73% ） ;when comparing the inhibitory effect against O^2- of the four hydrolysates,it showed positive correlation with the hydrolysis degree.
出处
《食品工业科技》
CAS
CSCD
北大核心
2009年第1期120-123,共4页
Science and Technology of Food Industry
基金
天津大学青年教师基金(5110110)资助
关键词
山羊酪蛋白
酶促水解
抑菌活性
抗氧化活性
caprine casein
enzymic hydrolysis
antimicrobial activity
antioxidative activity
