Antioxidative effects of stabilized and unstabilized defatted rice bran methanolic extracts on the stability of rice bran oil under accelerated conditions

Abstract

The present research assessed the antioxidant activity against the synthetic 1, 1-diphenyl-2-picrylhydrazyl radical, and β-carotene-linoleic acid assay of the methanolic extracts of defatted rice bran from stabilized and unstabilized rice bran. The effects of the extracts (0.1 and 0.25% w/w) on the oxidative stability of refined-bleached rice bran oil were determined and compared with those of BHA (synthetic antioxidant). The study was carried out over a 168 hr period at 70°C and the progression of oxidation was measured by peroxide value, p-anisidine value, and thiobarbituric acid-reactive substances (TBARS). The relative % of residual α-tocopherol and γ-oryzanol of the rice bran oil containing methanolic extracts of stabilized and unstabilized defatted rice bran during storage at 70°C were studied.