A laboratory study for developing an aqueous process to make skimmed soymilk

Abstract  Soymilk was extracted from soybeans at room temperature, using water-to-bean ratios of 10∶1 and 30∶1 to obtain two different protein concentrations. Defatting of soymilk by centrifugation was studied with a focus on the effect of protein concentration. A kinetic model, with a rate constant k and a fat-protein binding constant K, was established by linear regression to describe the defatting process in both cases. Ahigh water ratio resulting in a low protein concentration was favorable to defatting. Based on these results, an aqueous process was developed for the production of skimmed soymilk, consisting of grinding, extraction, cooking, centrifugation, and ultrafiltration. The product obtained had about 3 wt% protein and 0.3 wt% fat and thus qualified as skimmed soymilk.