摘要
为减少进口发酵剂的使用,降低国内乳制品的生产成本,国内需要自主研发发酵剂,水解脱脂乳培养基的优化是发酵剂制备过程中的一个重要环节。为制备有利于乳酸菌生长的水解脱脂乳培养基,本研究首先以发酵乳杆菌V9为试验菌种,筛选出水解脱脂乳最适的蛋白酶,再通过单因素与正交实验对制备脱脂乳水解液的温度、时间、pH值、加酶量进行优化。结果表明,最适水解条件为:在p H为8.5的12%脱脂乳中按25 U/mL接入碱性蛋白酶,55℃水解1 h,以此水解脱脂乳为培养基培养乳酸菌活菌数达到2.5×10^9CFU/mL,较脱脂乳培养基中的活菌数提高了1.74倍。利用此优化培养基培养鼠李糖乳杆菌grx19和植物乳杆菌S7,得到的活菌数分别较脱脂乳培养基提高了1.50和1.62倍。
In order to reduce the use of imported starter and reduce the production cost of domestic dairy products,it is necessary to develop starter independently in China.The optimization of hydrolytic skim milk medium is an important link in the preparation of starter.In order to prepare hydrolytic skim milk medium which is beneficial to the growth of lactic acid bacteria,the optimum protease of water free milk was screened out by using Lactobacillus fermentation V9 as the experimental strain.Then the temperature,time,pH value and enzyme dosage of defatted emulsion hydrolyses were optimized by single factor and orthogonal experiment.The results showed that the optimum hydrolysis conditions were as follows:adding 25 U/mL alkaline protease into skimmed milk at 12%with pH of 8.5,hydrolyzing at 55℃for 1 h,the number of living lactic acid bacteria in skimmed milk medium reached 2.5×10^9 CFU/mL,which was 1.74 times higher than that in skimmed milk medium.When Lactobacillus rhamnoides grx 19 and Lactobacillus plantarum S7 were cultured in this optimized medium,the number of living bacteria was 1.50 and 1.62 times higher than that in skim milk medium,respectively.
作者
黄欣媛
苏剑波
王志鹏
王俊杰
陆震
印伯星
关成冉
HUANG Xin-yuan;SU Jian-bo;WANG Zhi-peng;WANG Jun-jie;LU Zhen;YIN Bo-xing;GUAN Chen-ran(Key Laboratory of Dairy Biotechnology and Safety Control,Yangzhou University,Yangzhou Jiangsu 22517,China;BloomageBiotechnology Corporation Limited Company,Jinan Shandong 250101,China;Jiangsu Provincial Dairy Biotechnology Research Center Yangzhou,Yangzhou Jiangsu 22517,China)
出处
《食品与发酵科技》
CAS
2019年第6期55-59,77,共6页
Food and Fermentation Science & Technology
