Abstract:In this paper, aqueous glutarate acid cassava starch esters (AGAC) and ethanolic glutarate acid cassava starch esters (EGAC) were prepared and characterized by FTIR, XRD and SEM. The viscosity, transparency, rheological properties, freeze-thaw stability, salt resistance and other physicochemical properties of AGAC and EGAC were studied. The results of microscopic characterization showed that the glutaric acid groups were successfully incorporated into the two esterified starch molecules, with their crystal structures remaining unchanged and the overall structure not greatly affected. Analysis with the Brabender viscometer revealed that the peak viscosity of AGAC increased, while the gelatinization temperature is significantly lowered. The gelatinization temperature of EGAC decreased along with greatly increased peak viscosity , although the viscosity stability was not improved. The transparency, freeze-thaw stability and shear resistance of AGAC paste and EGAC paste were greater than those of the original starch, with AGAC and EGAC having lower salt resistance than the original starch, that is, their thermal paste stability and salt resistance had not been improved. EGAC had greater transparency than the original starch but smaller than AGAC, with the freeze-thaw stability and shear resistance slightly better than that of AGAC and original cassava starch. After the introduction of glutaric acid group, the transparency, freeze-thaw stability, stability and shear resistance of cassava starch have been improved to some extent.
