双歧杆菌双元蛋白酸奶中特定菌含量及酸度的检测

THE DERTERMINATIOU OF THE BIFIDOBACTERIUM CIND ACIDITY IN THE YOGURT OF BIFIDOBACTERIUM AND DOUBLE PROTEIN

目的 :检测双歧杆菌双元蛋白酸奶中发酵前后以及在贮藏期间的双歧杆菌和乳酸菌活菌数及酸度的变化。方法 :应用改良MRS琼脂平板法检测含菌量 ,应用吉尔涅尔度表示酸度 (°T)。结果 :双歧杆菌双元蛋白酸奶中双歧杆菌含量为 3 1× 10 7CFU/ml,乳酸菌含量为 4 1× 10 8CFU/ml;°T为 6 5± 5。随着贮藏进程的延长 ,特定菌的含量随贮藏期进程而下降 ,第 4～ 5天下降明显 ;°T随贮藏期延长而逐渐上升 ,保质期内°T为 75～ 110之间。结论 :双歧双元蛋白酸奶符合酸奶国家GB2 74 6～ 1999标准。

objectives:The change of Determimafin the number of living lactis and Bifidobacterium and the change of pH value of yoghurt with Bifidobacterium and double protein before and after the fermentation as well as in the storing period.Method:Using improved MRS as medium to deterimine the number of bacteria and °T indicated acidity.Results:The number of Bifidobacterium was to 3 1×10 7CFU/ml,the number of lactis was to 4 1×10 8CFU/ml and descended with the extension of storing and obviously descended on 5～6 day.°T was65±5 and ascended with the extension of storing between 75～110 Conclusion:The Bifidobacterium Yoghurt accorded with the standard of GB2746 1999