In soybean oil suceptible to oxidation the authors studied the antioxidant activity of the vitamin A as retinol acetate and the beta-carotene was studied. The oxidation index of the system was determined by peroxide and malonaldehyde values during the intervals from 24 to 72 hours and profile of the linoleic and linolenic acids after 144 hours of oxidation. It was observed that the retinol acetate had an antioxidant activity greater than beta-carotene. The antioxidant activity of retinol acetate and beta-carotene were compared to the butyl hidroxi toluene (BHT) and was observed that the antioxidant efficiency was directly proportional to degradation resistance of them in the oxidative system. The retinol acetate, as such BHT, showed a fast interaction with actives radicals, in the beginning of the addition to the soybean oil, reducing the oxidation level when compared to the control.
beta-carotene; vitamin A; retinol acetate; antioxidant activity
