Chemical, physical, and functional properties of Thai indigenous brown rice flours.

Abstract

Thai indigenous brown rice flours from Nakhon Si Thammarat, Thailand, namely Khai Mod Rin (KMRF) and Noui Khuea (NKRF), were assessed for quality aspects in comparison with brown Jasmine rice flour (JMRF) and commercial rice flour (CMRF) from Chai Nat 1 variety. All the rice flours had different chemical composition, physical characteristic, and techno-functionality. The KMRF, NKRF, and JMRF were classified as a low amylose type (19.56-21.25% dw). All rice flours had low total extractable phenolic content (0.1-0.3 mg GAE/g dw) with some DPPH● scavenging activity (38.87-46.77%). The variations in the bulk density (1.36-1.83 g/cm3), water absorption capacity (0.71-1.17 g/g), solubility (6.93-13.67%), oil absorption capacity (1.39-2.49 g/g), and swelling power (5.71-6.84 g/g) were noticeable. The least gelation concentration ranged from 4.0 to 8.0% where KMRF was easier to form gel than JMRF, and NKRF/CMRF. The foam capacity of the flours was relatively low (1.30-2.60%). The pasting properties differed among rice flours and the lowest pasting temperature was observed in CMRF. Overall, the chemical, physical, functional, and pasting qualities of flours were substantially influenced by rice variety. The findings offered fundamental information on Thai indigenous rice flour that can be used in food preparations for specific uses.