Research on soybean curd coagulated by lactic acid bacteria.

Chinese traditional soybean curd is coagulated by calcium salt. In order to investigate the feasibility of soybean curd coagulation by lactic acid bacteria, we studied the effective factors in soybean curd coagulation when using common soybean curd strains. In soybean curd concentration, incubating time and temperature as well as the inoculated amount and the edible gum additives were studied as the coagulating factors of soybean curd fermented by lactic acid bacteria. Based on the single factor and orthogonal experiment design, the optimized conditions of lactic acid bacteria fermentation curd was determined as follows: soybean curd concentration 12.5%(v/v)and the fermentation conducted at 42°C for 5 hours when the inoculating amount was 4.0% and edible gum additives was 1.4% (carrageenan 1.0% (m/v), soluble starch 0.4% (m/v)). Under the optimum conditions, the water-holding rate of the bean curd was measured as 69.82%, and the gel strength was 25.6 g/cm(2). Compared with the traditional tofu coagulated by calcium salt, our products has less off-flavor and softer texture, which was accepted as new type of soybean curd according to the overall sensory evaluation.