This study investigated the physicochemical properties of four commercially available gelatinized rice flours. The proximate composition and the contents of apparent amylose, resistant starch, soluble starch, and total starch were analyzed. Hydrolysis rate, particle size, gelatinization, and retrogradation characteristics of the samples were also evaluated. Overall, significant differences in quality were observed among the samples, indicating a broad range of sample qualities in the market. Notably, the content of resistant starch varied by up to fivefold among the samples, probably due to the distinct gelatinization, cooling, and drying processes used during their production. Variations in starch hydrolysis rates were also noted among the samples, which were attributed to differences in the ratios of amylose to amylopectin. Furthermore, the characteristics associated with gelatinization and retrogradation varied among the samples, possibly influenced by differences in the rice variety, the amylose-to-amylopectin ratio, and particle size. The findings of this study may benefit researchers and practitioners aiming to develop processed food materials based on gelatinized rice flour.

Keywords: gelatinized rice flour, resistant starch, starch hydrolysis, amylose content