具有结合胆酸盐作用卵形鲳鲹蛋白酶解物的制备和分子量分布研究

以卵形鲳鲹(Trachinotus ovatus)鱼肉为原材料,以酶解产物与胆酸盐的体外结合率为指标,从5种常用食品用蛋白酶中筛选最优蛋白酶。进而采用正交法优化酶解条件,以提高酶解产物的胆酸盐结合率,并采用GPC法分析产物中蛋白肽的分子量分布情况。结果表明,胰蛋白酶酶解产物(100 mg·m L~(-1))与胆酸钠、甘氨胆酸钠和牛磺胆酸钠等3种胆酸盐的体外结合能力均好于其他4种蛋白酶,结合率分别达到42.1%、33.5%和30.1%,分别相当于降血脂药物考来烯胺散(20 mg·m L~(-1))的78.3%、74.4%和76.8%;经过正交试验优化的制备卵形鲳鲹蛋白肽的工艺条件为酶解时间2 h,加酶量2 000 U·g~(-1),料液比1∶4(g·m L~(-1)、p H 8、37℃)。该条件下酶解产物(20 mg·m L~(-1))对甘氨胆酸钠体外结合率达到同浓度阳性对照物(考来烯胺散)的48.3%,酶解产物中相对分子量3 k D以下的肽类组分占总蛋白水解物的77.30%。

Production of bile acid salts binding hydrolysate from Trachinotus ovatus and its molecular weight distribution

Taking ovate pompano (Trachinotus ovatus) meat as raw material and taking enzymatic hydrolysate and bile salts in vitro binding rate as index,we screened the optimal protease from five kinds of food protease.Then we used orthogonal design to optimize hydrolysis conditions in order to improve the binding rate of bile acid salts and used GPC method to analyze the molecular weight distribution of peptides.The results show that the tryptic hydrolysates had higher binding rate than that of the other protease hydrolysates,and the in vitro binding rate of sodium cholate,sodium glycocholate and sodium taurocholate by enzymatic protein (100 mg·mL-1) was 42.1%,33.5% and 30.1%,respectively,which was 78.3%,74.4% and 76.8% equivalent to the positive control cholestyramine (20 mg·mL-1).The maximum percentage of sodium glycocholate hydrate binding rate was obtained under the conditions:hydrolytic time of 2 h,enzyme additives of 2 000 U·g-1,meal-to-water ratio of 1:4 (g·mL-1,at pH 8,37 ℃).Under the optimal condition,the in vitro binding rate of sodium glycocholate hydrate by enzymatic hydrolysate (20 mg·mL-1) was corresponding to 48.3% of positive control cholestyramine at the same concentration.The relative molecular weight of peptides below 3 kD in enzymolysis products accounted for 77.30%.