Antioxidant Activities of á-Tocopherol, Herbalox and Butylhydroxytoluene in Palm Olein Systems

Abstract

This study was carried out to determine possible synergism and antagonism in blends of natural and synthetic antioxidants for protection of palm olein at high temperatures. Three primary antioxidants: (±)-á-tocopherol (Vitamin E), Rosemary extract (Herbalox) and butylated hydroxytoluene (BHT) were used in a mixture experiment for the protection of palm olein at steaming and frying temperatures. Results showed that palm olein was composed of 61.3% and 21.2% of oleic and linoleic acids respectively. Iodine value, unsaturated/saturated ratio and diene equivalent were 54.14, 4.9 and 22.89, respectively. The antioxidants protected palm olein against oxidation to different degrees in the following order: Butylated hydroxyl toluene > Rosemary extract > á-tocopherol at concentrations of 0.1% of the oil. The antioxidant protection factors were 1.63, 1.40 and 0.96 for butylated hydroxyltoluene, Rosemary extract and á-tocopherol respectively. Antioxidant synergism was observed in combinations of vitamin E/butylated hydroxyltoluene, and Rosemary extract/butylated hydroxyltoluene but antagonism was observed in vitamin E/ Rosemary extract. The findings of this study showed that Rosemary extract and butylated hydroxyltoluene and their mixtures are observed to be better antioxidants than vitamin E and their combinations with vitamin E in palm olein systems at 110oC.