Conversion of Isoflavone Glycosides to Aglycones in SoyLife and Soymeal Using β‐glycosidase

Conversion of isoflavones from glycosides to aglycones in SoyLife and soymeal using varying concentrations of β‐glycosidase, and different pH conditions and temperatures was investigated. The best conditions for the conversion of glycosides to aglycones were pH 5.0, 50 °C, and 5 h incubation with 5 units β‐glycosidase/g Soy Life and 1.5 units/g soymeal. Under these conditions, the amount of genistein, daidzein, and glycitein in Soy Life treated with β‐glycosidase were 4.22, 11.52, and 11.85 μmol/g compared to untreated controls of 0.26, 0.97, and 4.43 μmol/g, respectively. In soymeal, the amounts were 3.21, 2.02, and 2.12 μmol/g compared to untreated controls of 1.23, 1.25, and 1.51 μmol/g, respectively. Mole percent recovery of genistein was 87% in Soy Life and 80% in soymeal, respectively.