Isolation, Characterization, and Modification of Starch Isolated From Waste‐Cooked Non‐Waxy Rice Water

ABSTRACT Raw starch's poor swelling, solubility, low shear rates, and low heat resistance limit their industrial applications. This work aimed to isolate and characterize the starch from the wasted rice water that remained after cooking. It was then modified using dry heat treatment (DHT) at 90, 120, and 150 °C for 48 h to explore its potential industrial applications. After investigation, it was found that swelling power and solubility decreased, whereas amylose content increased dramatically from 8.07% ± 0.01% to 22.57% ± 0.07% as the treatment temperature increased. SEM results showed an aggregated structure with the appearance of ruptured granules. Dry heating rice starch at 90 °C significantly reduced XRD diffraction peaks and FTIR intensity ratios (1047/1022 and 995/1022). Apparent viscosity and shear rate values were higher than raw starch. This suggested higher stability of starches after DHT, which was also confirmed by TGA analysis as decomposition temperature increased from 260 to 277 °C. In addition, modified starch with a greater peak viscosity can be added to meals as a thickening agent. The modification of starch leads to the conclusion that its diverse properties may be aimed at different areas of the food business.