Antioxidant activity of sesame oil on oxidative stability of olive oil

Abstract

In this study, the effects of blending sesame oil with olive oil at different concentrations (5%, 15% and 25%) and storing the oil blend at 60C for 30 days in relation to the physicochemical properties and fatty acid composition were determined. Peroxide value, free fatty acid, p-anisidine, K232 and K270 values were analyzed on the 15th and 30th days in olive oil as well as sesame/olive oil blend. After 15 days of storage, the lowest peroxide value (3.73 meq O2/kg) was obtained in olive oil containing 5% sesame oil, while olive oil containing 25% sesame oil has lowest peroxide value of 4.95 meq O2/kg after 30 days of storage. The lowest free fatty acid values were found in olive oils, with the values of 1.45% for 15th day and 1.67% for 30th day. The result revealed that peroxide and p-anisidine values increased, while the free fatty acid and ultraviolet absorption at 232 and 270 nm decreased during storage at 60C. Minimum free fatty acid (1.45%) was found in olive oil stored for 15 days, while the K values were in the range (0.01-0.02) following analysis on 30th day. This study revealed that addition of sesame oil to olive oil improved the antioxidative property of oil blends.