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The antioxidants activities of sumac extract at various concentrations were evaluated in natural rice bran oil and canola oil stored at 65º.C, for 35 days. The concentrations of extracts added into oil were 0.1%, 0.3% and 0.5%. Antioxidants effect was determined by the measurement of peroxide value. In addition determine the fatty acid and rancidity of fats in the rice bran oil and canola oil proximate composition and active groups of sumac powder. The results indicated that the mean gross rancidity of fats of rice bran oil was 1%, 3.7%, 205% and 0.8%, 5.58%, 202% of canola oil. The percentage of saturated fatty acids of rice bran oil was 16.73% and 11.70%, respectively which was higher than the canola oil (3.93% and 12.64% respectively). On the other hand the percentage of Poly Unsaturated Fatty Acid of of rice bran oil (30.17% and 2.14%, respectively) which were lower than the canola oil (30.71% and 15.40% respectively). Extract at 0.5% in the rice bran oil after 14 into 35 days of storage had better antioxidant activity (12.04%, 15.22%, 17.3% and 21.46%) than the control sample. On the other hand, extract at 0.5% in the canola oil had better antioxidant activity except for after 14 and 35 days of storage. The rate of inhibition of autoxidation in the rice bran oil and canola oil increases by increasing the concentration of extracts of sumach after 35 days of storage. On the other hand, the percentage rate of inhibition of autoxidation in the rice bran oil due to the presence of total natural antioxidants was 1.25% but it was 3.75% in the canola oil. The results showed that Sumac extract is also promising as a source of natural antioxidants.

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