Effect of pre-incubation on yoghourt freeze-dried starter

The effect of preincubation on the viability of freeze-dried yoghurt starter cultures was studied.After the suspension of cultures of Lactobacillus bulgaricus and Streptococcus thermophilus was pre-incubated under 42 ℃ for 60 min,the survival ratio of freeze-dried starter culture was increased from 71% to 81%,and the coagulation time was reduced from 210 min to 185 min.Experiment of 4 ℃～90 d storage stability of freeze-dried yoghurt starter showed that the survival ratio was 62% with a increase of 23%,and the corresponding coagulation time was 245 min,with a reduction of 45 min,compared to the control group,respectively.