瑞士乳杆菌发酵制备牦牛乳酪蛋白源性降血压肽的工艺研究

目的:以牦牛乳源酪蛋白为原料,利用瑞士乳杆菌,对发酵法制备降血压肽的工艺进行初步探讨.方法:试验首先采用凝乳酶沉淀法从耗牛乳中提取酪蛋白,依据瑞士乳杆菌的发酵特点,按5％(体积比)接菌量进行发酵制备降血压肽.然后并以降血压肽对血管紧张素转换酶(ACE)的抑制率为指标,主要探讨了底物浓度、pH值、发酵时间三因素对瑞士乳杆菌发酵法制备降血压肽工艺的影响.结果:在接菌量为5％,其他三因素各设置五个水平进行工艺优化,最优工艺条件为:底物浓度4％、发酵pH值8.0、发酵时间16 h.此工艺条件下ACE抑制率可达约68％.结论:通过实验说明底物浓度、pH值、发酵时间等参数的控制对发酵酪蛋白制备抑制肤很重要,此试验数据为后续进一步完善制备降血 压肤的实验奠定了重要的基础.

The Studies on the Preparation of Antihypertensive Peptides of Yak Milk Casein Fermentation with Lactobacillus Helveticus

Objective： Yak Casein and Lactobacillus helveticus as raw material, the preparation process of antihypertensive peptides using fermentation method was discussed. Methods： Firstly we extracted casein from yak milk using rennet precipitation method, and preparated antihypertensive peptides of fermentation using 5 % （volume ratio） inoculation amount according to the fermentation characteristics of Lactobacillus helveticus.Then inhibitory rate of antihypertensive peptides to angiotensin- converting enzyme ACE） as indicators, we mainly discussed the influence of the substrate concentration, pH value, the fermentation time to antihypertensive peptides preparation of fermentation method. Results： While the inoculums was 5 %, other three factors of each set five levels to process optimization, the optimum conditions as follows： substrate concentration was 4 % pH value of fermentation was 8.0, the fermentation time was 16h. The ACE inhibition rate was almost to 68 % in this condition. Conclusion： the control of substrate concentration, pH value, the time of fermentation and other parameters are very important to preparation of antihypertensive peptides. This experimental test data laid an important foundation for further preparation of antihypertensive peptides more efficiently.