Abstract: 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.
冶成君. 凝固型普通酸奶与牦牛乳酸奶的发酵特性[J]. 食品与发酵工业, 2014, 40(12): 106-110.
YE Cheng-jun. Study on fermentable character of condensation cow yogurt and yak yogurt[J]. Food and Fermentation Industries, 2014, 40(12): 106-110.