西兰花茎叶蛋白酶解条件优化及其降血脂活性

为优化胰蛋白酶水解西兰花茎叶蛋白的酶解条件及研究西兰花茎叶蛋白肽辅助降血脂活性,选取pH、温度、加酶量和底物浓度为自变量,水解度为响应值,利用响应面分析法,确定最佳酶解工艺参数;通过小鼠喂养实验分析西兰花茎叶蛋白肽对小鼠甘油三酯(TC)、总胆固醇(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、谷丙转氨酶(ALT)、谷草转氨酶(AST)含量以及动脉硬化指数(AI)的影响。结果表明,西兰花茎叶蛋白胰蛋白酶酶解的最优条件为:pH7.5,温度50℃,加酶量2000 U/g,底物浓度4%,水解度22.37%±0.46%;西兰花茎叶蛋白肽低剂量组(300 mg/kg)小鼠血清TC、ALT含量与模型组相比有极显著差异(P<0.01),TG、LDL-C含量与模型组有显著差异(P<0.05),对AST含量无明显降低作用;中(600 mg/kg)、高(1200 mg/kg)剂量组样品在降低TC、TG、LDL-C、ALT和AST含量上与模型组有极显著差异(P<0.01);高剂量组(1200 mg/kg)对HDL-C含量无明显影响,低(300 mg/kg)、中剂量组(600 mg/kg)能增加HDL-C含量,与模型组间有极显著差异(P<0.01),有利于AI指数的降低。以上结果表明西兰花茎叶蛋白肽具有良好的降血脂活性。

Optimization of Enzymatic Hydrolysis Conditions and Hypolipidemic Activity of Broccoli Stem and Leaf Protein

In order to optimize the enzymatic hydrolysis conditions of trypsin hydrolysis of broccoli stem and leaf protein and to study the activity of broccoli protein peptide to reduce blood lipid,the pH,temperature,enzyme amount and substrate concentration were selected as independent variables,the degree of hydrolysis was the response value,and the response surface was used to determine the optimal enzymatic process parameters. The effect of the broccoli stem and leaf protein peptide on mouse triglyceride(TC),total cholesterol(TG),low density lipoprotein cholesterol(LDL-C)high-density lipoprotein cholesterol(HDL-C),alanine aminotransferase(ALT),aspartate aminotransferase(AST),and arteriosclerosis index(AI)were analyzed though mouse feeding experiments. Results showed that,the optimal conditions for enzymatic hydrolysis of broccoli stem and leaf protein trypsin were:pH7.5,temperature 50℃,enzyme dosage 2000 U/g,substrate concentration 4%,hydrolysis degree 22.37%±0.46%. The contents of TC and ALT in serum of broccoli stem and leaf protein peptide low dose group(300 mg/kg)were significantly different from those of model group(P<0.01). The contents of TG and LDL-C were significantly different from those of model group(P<0.05). There was no significant decrease in AST content. The contents of TC,TG,LDL-C,ALT and AST in the medium(600 mg/kg)and high(1200 mg/kg)dose groups were significantly lower than those in the model group(P<0.01). The high dose group (1200 mg/kg) had no significant effect on the content of HDL-C. The low dose group(300 mg/kg)and the medium dose group(600 mg/kg)could increase the content of HDL-C,which was significantly different from the model group(P<0.01),and was conducive to the reduction of AI index. The above results showed that broccoli stem and leaf protein peptide had good hypolipidemic activity.