Study on fermentation processing techonology of the soybean yogurt

This study investigated the processing technologies of the soybean yogurt fermented by the mixed starter of Streptococcus thermophilus,Lactobacillus delbrueckii and Lactobacillus acidophilus,using the soybean as raw material.The optimum processing technology was determined by single factor experiment and orthogonal experiment,which were as follows: ration of Streptococcus thermophilus,Lactobacillus delbrueckii and Lactobacillus acidophilus 1∶1∶2,inoculum of mixed strain 4%,fermentation temperature 43 ℃,sucrose addition 6%,and fermentation time 4h.Under theses conditions,the number of live bacteria of the soybean yogurt processed under the above condition was 2.8 ×108 mL-1.The soybean yogurt took on pure flavor of soybean and lactic acid,smooth texture,sour and sweat delicious taste.