Fermentation properties of potential probiotic Lactobacillus fermentum in soymilk.

Selected eleven strains of potential probiotic Lactobacillus fermentum which were isolated from traditional dairy products in Tibet,Inner Mongolia and Mongolia,were used as starter culture for the fermentation of soymilk.The viable count of strains,the pH value,titratable acidity,viscosity,free amino nitrogen(FAN) and the syneresis of soymilk were determined in the duration of fermentation at 42 ℃ and storage at 4 ℃ respectively.The sensory quality of each fermented soymilk was evaluated after 24 hours storage.The results showed that the pH of all fermented soymilk significantly decreased,while the titratable acidity and viscosity significantly increased during the fermentation(P0.05).The sensory evaluation showed F6SF group with favourable stretchability had no whey separation in the exquisite surface,and the total score of apparent,odor and flavor was significantly higher than others(P0.05),separately.Our results indicated that L.fermentum F6 was good candidate for applying to the probiotic fermented set soymilk.