Preparation of Yoghurt of Lactobacillus Bifidus

The Lactobacillus bifidus yoghurt fermentation technology was study in the paper. The batch inoculation method was adopted during fermentation process. The optimal fermentation technology was as follows: 5% L. bifidus culture was inoculated in skim milk containing 8% sucrose. After fermented for 8 h at 39℃, the 4% mixed culture of 1:1 ratio of Lactobacillus bulgaricus and Streptococcus thermophilus was inoculated again, and fermentation continued for the other 3 h at 42 ℃. The semisolid products appeared excellent flavor. The viability of L. bifidus reached to 3.9×108/mL, the acidity of products is 96°T, and the aldehyde content is 16.90 mg/L. It could be preserved for 6 days at 4℃.