Rheological properties of sweet potato starch before and after denaturalization

Abstract

Based on the sweet potato starch, cationic starch, acetic starch and cationic-acetic compoundedly modified starch were made through chemical denaturalization. The above three kinds of static rheological parameter and dynamic rheological parameter were measured, respectively. The experimental result reveals that the thermal stability of starchy viscosity increases after chemical denaturalization. Under the condition of identical shearing rate, the shear stress of cationic-acetic ester compoundedly modified sweet potato starch paste is the largest among these kinds of sweet potato starch. This attributes to a phenomenon of shearing thinning. Furthermore, raw sweet potato starch has a larger gel intensity than that of modified starch.

Keywords

sweet potato / modified starch / rheological properties / pasting / shearing rate