Analysis of Antioxidant Activity of Three Rice Varieties

Background and purpose: Rice (Oryzasativa L.) is one the most important staple food in the world. There is an increasing interest for pigmented varieties, due to their antioxidant properties. In this research, the antioxidant activities in different parts of three varieties of rice were studied. White rice, brown rice, husk, and bran of Fajr, Hashemi and KB13 were extracted by maceration method using methanol as a solvent. Antioxidant capacity was assessed by three different methods. The total phenolic and flavonoid contents were also determined. Ferulic acid and p-coumaric acid were detected by High-Performance Liquid Chromatography (HPLC). KB13 rice bran showed the highest amount of total phenolics (319.83 ± 15.21 mgGAE) and flavonoid contents (77.58 ± 3.8 mgQE). The Hashemi crude bran extract was significantly different from other extracts in DPPH radical scavenging activity (P<0.001). The barn of three rice varieties showed the highest activity in nitric oxide radical scavenging activity (P<0.001). The bran of Hashemi and KB13 showed the highest amount of ferulic acid (26.21 mg/g extract) and p-Coumaric acid (3.66 mg.g extract), respectively. The Iranian Fajr, Hashemi and KB13 rice varieties were found to have significantly higher antioxidant activities and total phenolic and flavonoid contents compared with other foreign samples reviewed.