Changes in properties of starch isolated from whole rice grains with brown, black, and red pericarp after storage at different temperatures

• Starches were isolated from pigmented rice grains stored for six months.
• Storage of rice grains at 40 °C reduced the extraction yield of starch.
• Storage of rice grains at 40 °C decreased the relative crystallinity of starch.

The aim of this study was to evaluate the physicochemical, morphological, crystallinity, thermal, and pasting properties of starches isolated from rice grains with brown, black, and red pericarp. Starch was isolated from the rice grains at initial storage time, and after 6 months of storage at different storage temperatures (16, 24, 32 and 40 °C). Starch isolated from the grains stored for 6 months at 40 °C showed darker coloration, surface deformation of granules, and a significant reduction in the extraction yield, final viscosity, enthalpy, and crystallinity, independent of the grain pericarp coloration. The time and storage temperature not influence the swelling power and solubility of starch isolated from grains with brown pericarp, while for the grains with black and red pericarp there was reduction in swelling power and solubility of starches isolated of grains stored at 40 °C. Grains stored at 16 °C showed minimum changes in starch properties.