RESUMO
The objective of this study was to characterize the effects of pH, protein concentration and calcium supplementation on thermal stability, at 140°C, of soy protein isolate (SPI) and soy protein hydrolysate (SPH) ingredients. Increasing pH between 6.4 and 7.5 led to significantly (p<0.05) higher mean heat coagulation times (HCTs) at 140°C, for all soy protein ingredients at 1.8, and 3.6% (w/v) protein. Increasing protein concentration from 1.8 to 7.2% (w/v) led to shorter HCTs for protein dispersions. Calcium supplementation up to 850mg/L, except in the case of supplementation of SPI 1 with calcium citrate (CaCit), decreased HCT for soy protein ingredient dispersions, at pH 6.4 - 7.5. No significant differences (p<0.05) were found in mean HCT for dispersions supplemented with calcium chloride (CaCl2) and those supplemented with CaCit at 450, 650 and 850mg/L Ca(2+), in the pH range 6.4-7.5.
