Aleksieva V
Vet Med Nauki. 1979;16(4):70-7.
The effect of lactic acid fermentation in Bulgarian yoghourt was studied by the development and decline of hygiene level indicating microorganisms--enterococci and coli-bacteriae. It was established that for the first 6 h after production of Bulgarian yoghourt, the quantity of enterococci (Str. faecalis, resp. Str. faecium) increases 5--6 times on the average, after the 12th hour it begins slowly to decrease and the number is reduced two times during storage for 7 days at 7--10 degrees C temperature of 6 days at 18--22 degrees C. The reduction in enterococci number is not fully correlated with the stage of lactic acid fermentation. Coli-bacteriae (E. coli) do not grow in number at the time the milk is turned into yoghourt. Their initial quantity diminishes along with the advance of the lactic acid process and after 24 h of milk storage at 18--22 degrees C or after 48 h at 7--10 degrees C they cannot be detected at all. The conclusion is drawn that enterococci are more suitable as hygiene level indicating microorganisms for hygienic evaluation of Bulgarian yoghourt, as compared to coli-bacteriae, due to their greater viability and longer survival in the product at the time of its production and during storage. It is recommended to perform the investigations on coli-forms not later than the 24th hour after yoghourt productions begins.
通过指示卫生水平的微生物——肠球菌和大肠杆菌的生长与衰退情况，对保加利亚酸奶中乳酸发酵的效果进行了研究。结果表明，在保加利亚酸奶生产后的最初6小时内，肠球菌（粪肠球菌和屎肠球菌）数量平均增加5至6倍，12小时后开始缓慢减少，在7至10摄氏度下储存7天或在18至22摄氏度下储存6天时数量减少两倍。肠球菌数量的减少与乳酸发酵阶段并不完全相关。在牛奶变成酸奶时，大肠杆菌数量不会增加。随着乳酸发酵过程的推进，其初始数量会减少，在牛奶于18至22摄氏度下储存24小时后或在7至10摄氏度下储存48小时后，就完全检测不到了。得出的结论是，与大肠杆菌相比，肠球菌更适合作为指示保加利亚酸奶卫生水平的微生物，因为它们在产品生产和储存期间具有更强的活力和更长的存活时间。建议在酸奶生产开始后不迟于24小时对大肠菌群进行检测。
