Thermal, structural and rheological behaviour of native and modified waxy corn starch with hydrochloric acid at different temperatures

In this study, samples of native waxy corn starch, waxy corn starch treated with HCl 0.15 mol L−1 at 20 and 50 °C, respectively, were analysed. The thermogravimetric curves showed similar behaviour with three main mass losses and a decrease in the thermal stability. The acid hydrolysis in low HCl concentration performed for 4 h caused a decrease in peak temperature (DSC), viscosity peak (RVA), gelatinisation enthalpy (DSC) and relative crystallinity (XRD), and an increase in the average roughness (NC-AFM). The X-ray diffraction patterns displayed the ‘A’ type for all the starch granules.