Physicochemical properties of rice (Oryza sativa L.) flour and starch of two Indonesian rice varieties differing in amylose content

Physicochemical properties of rice flour and rice starch differing in amylose content were evaluated in Setra Ramos and Mentik Susu rice varieties. The objectives of this research was to determine the physical properties i.e. thermal, X-ray diffraction patterns and chemical properties i.e. moisture content, lipid content, protein content, total starch content, amylose content, FT-IR analysis, and 13C NMR analysis of rice flour and rice starch of Setra Ramos and Mentik Susu. It was found that the rice starch of Setra Ramos had the highest To and Tp may be due to the higher of their amylose content whereas the rice flour of Mentik Susu had the highest Tc and ΔH. The rice starches of Setra Ramos and Mentik Susu had the higher moisture content than rice flours of Setra Ramos and Mentik Susu whereas the lipid content and protein content of rice starch of Setra Ramos were lower than its rice flour. The rice flour of Setra Ramos had the higher amylose content (23.69%) than rice flour of Mentik Susu. The spectra FT-IR for rice flour and rice starch of Setra Ramos and Mentik Susu showed a band at 400 and 700 cm-1 to skeletal mode of amylose and amylopectin. The peak in 100 ppm of spectra 13C NMR confirmed that the rice starches of Setra Ramos and Mentik Susu had A-type X-ray diffractions patterns.