Assaying Antioxidant Characteristics of Sesame Seed, Rice Bran, and Bene Hull Oils and their Unsaponifiable Matters by Using DPPH Radical-Scavenging Model System

DPPH radical-scavenging activity of the bene hull oil (BHO), sesame oil (SEO), rice bran oil (RBO), the oil's methanolic (CH3OH/H2O, 80:20 v/v) or hexane extracts, and their unsaponifiable matters fraction were measured and compared with each other. As a radical-scavenger, SEO was significantly stronger than RBO and BHO, respectively. Unlike BHO and RBO, the unsaponifiable (USM) fraction of the SEO could not considerably scavenge the free radicals at the concentrations studied. The contribution of aqueous methanolic and hexane extracts of the SEO to the inhibition of the DPPH radicals were calculated to be about 75 and 25%, respectively. The aqueous methanolic extract of the RBO could not considerably scavenge the free radicals at the concentrations experimented and the inhibition activity belonged mainly to the hexane extract. The DPPH radical-scavenging active components of the BHO were approximately distributed equally (48 and 52%) between the two extracts.