Comparative on the Hypoglycemic and Lipid-lowering Activities in Vitro of Crude Polysaccharides from Fermented Bean Flour by Two Types of Bacteria

Bacillus subtilis and Lactobacillus casei were commonly used in the production of fermented bean products. The effects of fermentation by two types of bacteria on the hypoglycemic and lipid-lowering activities of crude polysaccharides from bean flour were analyzed. In this study, 8 kinds of crude polysaccharide samples from fermented edible beans by the two types of bacteria were prepared. And the composition, water solubility, in vitro hypoglycemic and lipid-lowering activity of crude polysaccharides from before and after bean flour fermentation by the two types of bacteria were compared and analyzed. The results showed that the content of uronic acid in the crude polysaccharide from fermented bean flour increased. The content of uronic acid in the crude polysaccharides from fermented bean flour by Bacillus subtilis (4.05%~22.46%) was significantly higher than that of the crude polysaccharides from fermented bean flour by Lactobacillus casei (2.63%~10.72%) (P<0.05). The water solubility of crude polysaccharides from fermented bean flour by the two types of bacteria was improved. The hypoglycemic and lipid-lowering activities in vitro of crude polysaccharides were increased through the fermentation process by Bacillus subtilis and Lactobacillus casei. The α-amylase inhibition rates of crude polysaccharides from soybean, cowpea and broad bean by Lactobacillus casei fermentation were significantly higher than that of crude polysaccharides by Bacillus subtilis fermentation (P<0.05). The binding capacities of sodium glycodeoxycholate with the crude polysaccharides from cowpea, red bean, mung bean, broad bean, kidney bean, lentil and pea by Bacillus subtilis fermentation were higher than that of crude polysaccharides by Lactobacillus casei fermentation. The binding capacities of sodium taurocholate with the crude polysaccharides from mung bean, broad bean, kidney bean, lentil and pea by the two types of bacteria fermentation were significantly improved (P<0.05). This study provided a theoretical basis for the development of fermented bean foods riched in active polysaccharides with the functions of hypoglycemic and lipid-lowering activities.