Production of kefir from soymilk with or without added glucose, lactose, or sucrose

The effects of added glucose, lactose, and sucrose on microbial growth, acid, and ethanol production, and galactosidase activity in soymilk fermented with kefir grains were studied. Immediately after the addition of kefir grains to soymilk, the lactic-acid bacterial counts were higher, but the yeast counts were lower than in milk kefir. After fermentation for 32 h, the concentrations of yeast, lactic acid, and ethanol in soymilk were significantly lower than those in milk kefir. Addition of 1% glucose to soymilk stimulated growth of lactic-acid bacteria and yeast, the production of lactic acid and ethanol, and the beta-galactosidase activity. Nevertheless alpha-galactosidase activity was suppressed by 1% glucose.