Evaluation of methods for the separation of gamma oryzanol from Iranian rice rran oil varieties

g-oryzanol is an unsaponifiable component of rice bran oil، composed of several kinds and has antioxidant activity similar to tocopherols. In order to separate g-oryzanol، four varieties of rice from north part of Iran have been selected. These varieties include «local Tarom»، «Fajr»، «Shirudi» and «Neda». rice bran oil was subjected to oil extraction after thermal stabilization. Column and HPTLC chromatography followed by GC/MS were employed for separation، purification and identification of g-oryzanol. The antioxidant activity of the isolated concentrates were determined 0. 01، 0. 05 and 0. 1 percent on tallow، a substrate suitable to evaluate antioxidant activity due to the lack of natural antioxidants. The results indicated that «Neda» variety had the highest content of oil and g-oryzanol but the obtained g-oryzanol from «local Tarom» variety showed the highest antioxidant activity.