Effect of physicochemical modification on granule morphology, pasting behavior, and functional properties of riceberry rice (Oryza Sativa L.) starch

•Riceberry rice is purple-pigmented rice that contains numerous health benefits.•Native starch was modified by physical, chemical, and a combination of both methods.•The modification of starch decreased the amylose content in all methods.•The glycemic index reduced from medium to low in every treatment, which is good for health.•Autoclave process resulted in high resistant starch and a low glycemic index. This study aimed to investigate the effects of different physicochemical modifications of Riceberry rice (Oryza Sativa L.) starch on its morphology, pasting behavior, and functional properties. The methods include HCl lintnerization (1 N, 1.5 N, 2 N), autoclaving (135 °C for 14 min), HCl lintnerization combined with autoclaving, and freeze-thawing (-20 °C for 30 min). The result demonstrates that all modifications applied to the native starch increased the resistant starch (RS) content. The autoclaved Riceberry rice starch showed the highest RS content (49.66 ± 0.14%) and lowest estimated glycemic index (eGI) (50.03 ± 0.01%), indicating a healthy, low glycemic food. All treatments improved the solubility and water holding capacity (WHC) of native starch without destroying granule structure, whereas swelling power decreased with increased acid temperature-dependent concentration. Autoclave treatment increased WHC significantly of the modified starches with the damaged starch granules. The color values of lintnerized starch were reduced due to the removal of color pigment anthocyanin. Therefore, the result of this study provides a better understanding of the various modification methods for the functional properties of Riceberry rice starches for potential applications in a wide range of food applications. [Display omitted]