Effect of adding natural food materials to edible oil on reducing autoxidation of its unsaturated fatty acids content

Abstract

 This fundamental study investigated a method to control deterioration in the quality of edible oil through autoxidation of its unsaturated fatty acid content by adding the natural food materials, green tea powder and pumpkin powder, at levels between 1 wt% and 5 wt%. The experiment was carried out at 40 °C for 12 days. The results showed that adding green tea powder at a level of 5 wt% limited the maximum peroxide value (POV), a measure of the primary products of autoxidation of unsaturated fatty acids, to 51%; reduced the carbonyl value (CV), a measure of the secondary products of the oxidation of unsaturated fatty acids, by 76%; and suppressed oxidative rancidity by 85%. Adding pumpkin powder at a level of 5 wt% reduced POV and CV by up to 15% and 32%, respectively, and oxidative rancidity by 36%.