Assessment and distinction of commercial soy protein isolate product functionalities using viscosity characteristic curves

To simplify the assessment method of soy protein isolate (SPI) functionalities, the viscosity and functionalities of commercial SPI products were studied. Viscosity value (y) increases with increasing concentration (x) and exhibits a highly significant correlation with the exponential equation y = a · ebx. The b values of products are gradually enhanced from dispersion, emulsion and injected to gel type. Products with low b values (<0.2), and high dispersivity were dispersion-type. Products having high b values (>0.4) and gel springiness were gel-type. The other products with centered b value (0.2–0.4), high solubility and emulsifying capacity were emulsion-type.