[ investigation on the antioxidant activity of essential oil of Zataria multiflora Boiss. In soy bean oil]

ABSTRACT

Great interest has recently been focused on the addition of herbs and their derivatives to foods and biological system, due to their well-known abilities to scavenge free radicals. The aims of this study were to evaluate the antioxidant activity of the essential oil of Zataria multiflora Boiss. and [ii] to use this essential oil as natural antioxidant in crude soy bean oil. In this study, essential oil was [i] analyzed by GC/MS and its chemical components were identified. The antioxidant activity of essential oil was investigated with DPPH? free radical scavenging and beta-carotene bleaching methods and was compared with synthetic antioxidant [BHT]. Also, the antioxidant activity of essential oil was determined by measuring peroxide and thiobarbituric acid values in crude soy bean oil [oven test]. Results showed that carvacrol [26.08%] and thymol [17.23%] were main phenolic components in the essential oil. The EC50 value of Zataria multiflora essential oil was determined as 2.22 +/- 0.04 mg/ml. This parameter for BHT was 0.58 +/- 0.02. By the beta-carotene bleaching system, antioxidant activity of essential oil at 0.45% was equal to 72% and for BHT at 0.1% was determined 81%. In oven test, the antioxidant activity of Zataria multiflora essential oil at 0.1% was almost equal to BHA at 0.02% in crude soy bean oil. The essential oil showed good antioxidant activity and therefore, it can be used as a natural antioxidant in some foods after complementary tests