Proximate nutritional composition and antioxidant properties of Oryza rufipogon, a wild rice collected from Malaysia compared to cultivated rice, MR219

Wild rice (Oryza rufipogon L) is known as an important germplasm that has specific desirable attributes and a high genetic diversity. The physicochemical and antioxidant properties of O. rufipogon Griff. (acc. IRGC105491), a wild rice collected from Malaysia that was used in a breeding program and a QTL mapping study, were assessed to determine the rice’s nutritional value compared with a commonly consumed rice cultivar MR219 (O. sativa subsp. indica). To identify and quantify the phenolic compounds in the rice extracts, Ultra Performance Liquid Chromatography (UPLC) coupled with a photodiode array detector (PDA) was applied. The results obtained were supported by a determination of the total phenolic compounds (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, tocopherols, tocotrienols, and the ferric reducing ability power (FRAP) of the respective extracts originating from the whole grain. The results indicated that O. rufipogon, irrespective of its poor appearance, contained high proximate nutritional composition and antioxidant properties. The grain of O. rufipogon consisted of 8.0% protein, 2.2% fat, and 25.0% amylose content all significantly higher than the ratios of MR219. Except for the percentage of inhibition DPPH ̇ radical, which was statistically at par with MR219, the antioxidant activity of O. rufipogon was higher than that of MR219. The high antioxidant activity of O. rufipogon was supported by the presence of high tocochromanol content higher than MR219. Oryza rufipogon extracts were also the most effective in antioxidative reactions. This study demonstrated that wild rice can be considered a valuable source of bioactive components with high antioxidant properties in breeding programs. Abbreviations: DPPH2,2-diphenyl-1-picrylhydrazyl; FRAPFerric reducing ability power; TPTocopherol; T3Tocotrienol; TPCTotal phenolic content.