Storage conditions affect soybean color, chemical composition and tofu qualities

Soybeans stored under four sets of conditions were analyzed for the changes in color, composition and their effects on yield and textural properties of tofu. Soybeans stored under the adverse conditions (84% relative humidity (RH), 30C) exhibited significant changes in tofu yield and textural quality as well as in color and total free sugar content with storage time. Significant correlations existed between soybean color and tofu yield within 6 months under the adverse storage conditions. Color changes may provide a rapid method for predicting soybean quality for making tofu after storage. Soybeans stored under mild (57% RH, 20C), cold (4C) and uncontrolled ambient conditions (garage) exhibited no significant changes in their color or composition except for moisture contents, and maintained good qualities for tofu making for up to 18 months.