酸马奶发酵过程中理化指标与细菌相的动态变化

分析了酸马奶发酵过程中(0~96 h)部分理化指标以及细菌群落的变化情况。结果显示酸马奶发酵96 h内p H为下降趋势,发酵初期迅速酸化,发酵后期下降速度缓慢趋于稳定,最低达到p H3.54;总蛋白质、脂肪含量存在一定的起伏变化,72 h达到最高值;乳糖含量减少,而乳酸含量增加;葡萄糖、半乳糖、乙酸、丙酸含量在发酵过程中处于较低的水平;细菌群落结构分析结果显示酸马奶发酵过程中存在丰富的细菌多样性,并且群落结构有明显的演替变化。乳杆菌属(Lactobacillus)为优势细菌属,在酸马奶发酵过程中12~24 h呈现出上升的趋势,而24~48 h时其含量下降。研究结果表明不同发酵时间酸马奶营养价值存有差异。 

Analysis of physicochemical parameters and bacteria community structure in the Koumiss' s fermentation process

To analyze the physicochemical parameters and bacteria community structure in the Koumiss 's fermentation process( 0 ~ 96 h). The main findings were introduced in following part. During the fermentation process,the p H value of Koumiss was declined at high speed in early period and then the decent speed was slowed down and finally reached to the minimum value( p H = 3.54). The total contents of protein and fats were fluctuant changed,and achieved to the maximum values at 72 h. The content of lactose was decreased,while the lactic acid was increased in the process of fermentation. The contents of glucose,galactose,acetic acid,and propionic acid were at low level during fermentation.The results of bacterial community structure analysis showed that there were abundant bacterial diversity and their dynamic community structures changed obviously in the Koumiss fermentation process. Lactobacillus was the dominant bacterial genus. Its content showed a rising trend during 12 h to 24 h,while decling at 24 h to 48 h.The result showed that there were differences in nutritional value of Koumiss at different fermentation period.