牦牛乳酪蛋白肽制备及乙酰化脱苦

摘要

采用碱性蛋白酶对牦牛乳酪蛋白进行水解,得到牦牛乳酪蛋白肽.以醋酸酐为酰化试剂,利用结构修饰的方法对牦牛乳酪蛋白肽进行脱苦研究,探讨醋酸酐添加量、pH对牦牛乳酪蛋白肽酰化度及苦味的影响.结果显示,碱性蛋白酶最佳水解条件为,温度55℃,pH7.0,酶添加量1.25％,反应3h.维持酰化反应pH7以上,产物乙酰化程度最高,醋酸酐的添加量与脱苦效果呈正比,当醋酸酐添加量为40％时,牦牛乳酪蛋白肽酰化产物的苦味基本消失.%Preparation of yak milk casein peptides by hydrolysis of yak milk casein with alkaline protease wasrnstudied. Yak milk casein peptides was modified to carry out on the debitterizing research by the acetic anhydridernof structural modification.The influence of the adding amount of acetic anhydride and pH on the degree of Yakrnmilk casein peptides acetylation and bitterness was discussed. The result showed that: the enzyme dosage ofrnsubstrate 1.25% ,pH7.0,55℃ ,3h had the optimum hydrolysis conditions. Maintaining acylation reaction pHrnabove 7, the degree of acetylation were the highest, the acetic anhydride adding amount proportional to therneffects of debittering. When acetic anhydride dosage was 40%,the bitterness of yak milk casein peptidernacylation product would be disappeared.