Application of Protease to Accelerate Sufu Ripening

Sufu is a series of fermented soybean products originated in China, which has a cheese-like texture and special flavor in orient food dishes. However, the disadvantages of high salt content and long ripen time holdback this famous soybean food from wide consumption and fast development in modern world. The object of this research was to investigate the effect of enzymatic acceleration sufu ripen period according to the concentration of amino acid nitrogen released and the sensory characteristics produced. The optimized enzymatic acceleration was obtained when 13% soya curd was proteolysis by 2.5% protease at the temperature of 50°C for 5 d and then inactivated at 100°C for 20min to denature the enzyme activity. Sensory evaluation of the final product showed that the quality of this novel sufu product was closely similar to the traditional one, which indicated the feasibility to accelerate sufu production by enzyme application.