凝固型普通酸奶与牦牛乳酸奶的发酵特性  

Study on fermentable character of condensation cow yogurt and yak yogurt

作　　者：冶成君[1] 

机构地区：[1]青海省畜牧兽医科学院,青海西宁810016

出　　处：《食品与发酵工业》2014年第12期106-110,共5页Food and Fermentation Industries

基　　金：国家人力资源和社会保障部基金项目留学人员科技活动项目择优资助项目:青海地震灾区凝固型牦牛乳酸奶的研究与开发(青人社厅函[2011]518号)

摘　　要：以牦牛乳为原料,在相同发酵条件下对凝固型普通酸奶和牦牛乳酸奶发酵特性进行了对比分析。结果表明,牦牛乳酸奶的p H值在发酵初期低于普通酸奶,而在整个发酵期内牦牛乳酸奶p H值下降幅度小于普通酸奶,但达到发酵终点时,最终p H值趋向于4.6;总糖度从原料乳至酸奶发酵终点均高于普通酸奶,在到达发酵终点时糖度都保持在4%左右;在整个发酵期内普通酸奶酸度的增高幅度要大于牦牛乳酸奶;牦牛乳酸奶的发酵时间为11 h,而普通酸奶发酵时间为6 h;发酵期2种酸奶活菌数变化趋势基本相同,随发酵时间的延长活菌数逐渐增多而后又降低,0～2 h普通酸奶低于牦牛乳酸奶,经4℃贮藏24 h后普通酸奶的活菌数降低而牦牛乳酸奶活菌数增多;牦牛乳酸奶的黏度要高于普通酸奶的黏度。Yak milk was used as raw material in this paper. Fermentable character of cow yogurt and yak yogurt were studied under the same conditions. The results showed that p H value of yak yogurt was lower than that of cow yogurt at the beginning of fermentation,but it declined less than that of cow yogurt throughout the fermentation period,and both of them tended to 4. 6 when the fermentation was finished. The content of total sugar in yak yogurt was higher than that in cow yoghurt from raw milk to end of yogurt fermentation,which retained 4% until the end of fermentation. Acidity of cow yogurt increased more rapidly compared to yak yogurt throughout the fermentation period. The fermentation time of Yak yogurt was 11 h,and the fermentation time of cow yogurt was 6 h. The change trends of living bacterial counts of these two yogurts were substantially the same,which increased gradually and then decreased with time passing. Living bacterial counts in cow yogurt was lower than that in yak yogurt between 0 h and 2 h. After storage at 4 ℃ for 24 h,the counts of living bacterial in cow yogurt decreased,but that in yak yogurt increased. Viscosity of yak yogurt was higher than that of cow yogurt.

关 键 词：牦牛乳 凝固型酸奶 发酵特性 

分 类 号：TS252.54[轻工技术与工程—农产品加工及贮藏工程]