Study on fermented processing of probiotic yoghurt

The probiotic yoghurt was manufactured by Lactobacillus bulgaricus,Streptococcus thermophilus,Lactobacillus casei and Lactobacillus reuteri.Through orthogonal test,the results showed that L.casei and L.reuteri was appropriate in fermentation.The optimum parameters for processing of probiotic yoghurt were:the ratio of L.bulgaricus∶S.thermophilus∶L.casei∶L.reuteri 3∶3∶2∶2,inoculation size 0.25%(DVS),sugar 8%,fermenting for 5h at 39℃.