Double chemical modification in rice starch: acid hydrolysis optimization process and phosphating

Abstract

The objective of this work was to carry out a double chemical modification in rice starch: the first modification was acid hydrolysis optimization as a preparatory step for the second modification, which consisted of phosphating. For the optimization of the acid hydrolysis process, the independent variables hydrolysis time (h) and acid concentration (N) were evaluated. We obtained the estimated coefficients of the adjusted model and significance for the responses of viscosity profile (Vmax), water solubility index (WSI), water absorption index (WAI), onset temperature (To), peak temperature (Tp) and ending temperature (Te). The values predicted by the model for the hydrolysis optimization process were time 2 h and 1.2 N for HCI concentration. The starch obtained after the hydrolysis process was modified with sodium tripolyphosphate and characterized. Phosphate starches were obtained with degrees of substitution of 0.012 to 0.019 and showed good functional and physicochemical properties.