Study On Fermentation Characteristic In Soy Milk With Six Probiotic Strains

The aggregation abilities, hydrophobicity, inhibitory effects to pathogens and the fermentation characteristic in soy milk of six probiotic strains(Lactobacillus casei Zhang,Bifidobacterium animalis V9,Lactobacillus acidophilus NCFM,Lactobacillus rhamnosus GG,Lactobacillus casei Shirota and Bifidobacterium animalis BB12) were evaluated. The results are as follows:In the process of fermentation, pH declined, titrable acidity increased and the ability of proteolysis by probiotic strains was also increased;the glucose and fructose were utilized to produce acid by all tested six strains , only B.animalis BB12 and B.animalis V9 could utilize the stachyose, raffinose and sucrose which contained in soybean.At the end of fermentation, the content of Lactic acid in the fermented soy milk samples were significantly higher(P<0.05) than control ,the content of acetic acid in the soy milk samples inoculated with B.animalis BB12 and B.animalis V9 was significantly higher than other strains (P<0.05).The content ofγ-aminobutyric acid and vitamin B6 in the soy milk samples were significantly higherthan control (P<0.05). The daidzin, glycitin and genistin can be significantly utilized by B.animalis BB12(P<0.05).The viable counts were 108cfu/g in the sample inoculated with B.animalis BB12 and L. rhamnosus GG, while in the other samples were 109cfu/g.