Comparison of Antioxidant Efficiency in Oven Aging and Addition of BHT for Rice Bran Extract

g-oryzanol is one of the strongest antioxidants. It inhibits oxidation and is only present in rice bran. This composition decrease cholesterol, which decreases the risk of atherosclerosis. Ther prestn study extracted antioxidant from two varieties of rice bran (Zayandeh Rood and Sazandegi) using methanol solvent and percolation. The extracts were added to edible oil without antioxidants in 100 and 150 ppm concentrations and incubated at 63°C at intervals of 0, 24, 48 and 72 h. Chemical changes and thermal stability of the samples were examined using a Rancimat, and the acid and peroxide contents and radical scavenging percentage were recorded. Statistical analysis was done using a completely randomized design and Duncan's test at α = 0.01 using SPSS 16 software. All tests were replicated 3 times. The results showed that the effect of rice bran extract was greater for the Sazandegi variety for stable oxidation by oven aging of soybean edible oil for 72 h than for the addition of BHT and was significantly different from other extracts (p < 0.01).