High hydrostatic pressure effects on immunoreactivity and nutritional quality of soybean products

The aim of this research was to evaluate the protein pattern, immunoreactivity and amino acid composition of soybean seeds and commercial tofu after treating by high hydrostatic pressure (HHP) (300 MPa, 15 min, 40 °C), as well as of sprouts obtained from unpressurised and HHP-treated seeds. HHP did not affect the electrophoretic profile of soybean seeds or tofu protein extracts, but lower intensity of some protein bands were observed in HHP-treated products. A significant (P ⩽ 0.05) reduced antigenicity was observed in the sprouts from HHP-treated seeds compared to the sprouts from untreated seeds, while higher antigenicity of the pressurised seeds compared with the untreated ones was found. HHP decreased the total essential amino acid content as well as two nutritional indexes, the Chemical Score (CS) and the Essential Amino Acid Index (EAAI), but only by 18%. The findings suggest that HHP applied to soybean seeds before germination could constitute a valuable technological approach for the industrial production of nutritive hypoallergenic soybean sprouts.