Effect of genotype, seed development stages, and processing treatments on Bowman-Birk inhibitor in soybean and its level in commercial soy products.

Bowman-Birk inhibitor (BBI) is a protease inhibitor that affects protein digestibility; however, it is increasingly being recognised as anutraceutical and cosmeceutical molecule. In the present study, BBI concentration during soybean seed development, its loss during processing treatments, and the level in commercial soy products were determined. Significant differences for BBI concentration were observed across the genotypes and seed development stages. Genotype × seed development stage interaction was also found to be significant (P<0.05) for BBI concentration. Boiling, autoclaving, microwave irradiation, and sprouting resulted in significant (P<0.05) loss of BBI. Minimum loss was observed in sprouting, while autoclaving for 5 min completely deactivated BBI. Microwave irradiation of the soaked seeds resulted in higher BBI loss than of dry seeds. Among the commercial soy products, BBI concentration was high in soy flour brands, minuscule in ready-to-cook miso soup and undetectable in extruded soy products and roasted soy nuts. [ABSTRACT FROM AUTHOR]