Inhibitory Effect of the Fermented Soybean Milk by Lactobacillus plantarum ST-III on Maltase

The inhibition effect of different fermented bean milks by Lactobacillus plantarum ST-Ⅲ on maltase(EC 3.2.1.20) was assayed in an improved in vitro model.Furthermore,the correlation of the fermentation degree(estimated by pH value)as well as the concentration of extract from fermented soybean milk on the inhibition effect was tested.The results showed the fermented soybean milk by Lactobacillus plantarum ST-Ⅲ demonstrated the strongest inhibitory activity to maltase.The inhibition intensity increased along with the elongation of the fermentation period.The IC50 of crude extract prepared from the 5 %(w/w)soybean milk fermented by Lactobacillus plantarum ST-Ⅲ for 24 hr was 3 mg/mL.