Objectionable Flavor of Soy Milk Developed during the Soaking of Soybeans and its Control.

Daidzein and genistein, which are responsible for the objectionable flavor of soy milk, increased during the soaking of soybeans, the first step of soy milk manufacturing. The maximum production of these isoflavone compounds occurred at 50°C and at pH 6.0 depending upon the temperature and pH of the soaking water. The production of these substances was strongly inhibited by glucono-δ-lactone which was a competitive inhibitor of β-glucosidases. It would appear, therefore, that β- glucosidases were responsible for the production of daidzein and genistein during soaking. [ABSTRACT FROM AUTHOR]