Evaluation of antioxidant activities of some phenolic compounds in mutton tallow olein

To evaluate antioxidant activity of some natural phenolics، tallow olein was employed as a lipid system. Since animal fats are weak in natural antioxidants، studying antioxidant activity will provide a desirable behavior profile for them. Edible sheep tail fat was effectively fractionated by acetone crystallization at constant temperatures of 25، 15 and 5°C. In order to stabilize mutton tallow olein، antioxidant activities of some phenolic compounds including gallic acid، caffeic acid، catechin،quercetin، tannic acid، ellagic acid and salicylic acid were studied in tallow olein as a lipid system، at 150 ° C at 40، 60، 80، 100، 200 and 400 mg/L concentrations، by measuring induction time. Rancimat apparatus was employed as a mean to evaluate the antioxidant activity. The results indicated that gallic acid had the highest stabilizing effect on tallow olein while ellagic acid had the least effect as primary antioxidants. Among phenolic compounds investigated، only salicylic acid showed no antioxidant activity which is in contrast to all other antioxidant compounds. The results showed that، in tallow olein، the antioxidant activities of the ellagic and tannic acid are comparable to α-tocopherol whereas quercetin، catechin، gallic acid and caffeic acid are much more potent than α-tocopherol.