EVALUATION OF THE ANTIOXIDANT EFFICIENCY OF BERRY EXTRACTS IN SUNFLOWER OIL

摘要

The efficiency of anthocyanin extracts of blackberries, red raspberries, sweet cherries and synthetic a-tocopherol on delaying lipid oxidation of sunflower oil during 14 day storage at 30 and 60 degrees C was comparatively studied. The oxidative stability of oil samples was monitored in terms of peroxide value (PV), thiobarbituric acid-reactive substances (TBARS) and differential scanning calorimetry (DSC). PV results showed improved oxidative stability of sunflower oil supplemented with natural extracts compared to control and oil containing a-tocopherol, with better abilities for red raspberry. Among natural extracts, blackberry showed improved antioxidant activity as measured by TBARS, compared to control, and significantly higher compared to oil supplemented with synthetic a-tocopherol after 14 days of storage at 60 degrees C. Similarly, DSC investigation revealed good protective effects of blackberry extract on sunflower oil during storage at both temperatures. These results may contribute to the future consideration of anthocyanin fruit extracts as potential additives to enhance oxidative stability of sunflower oil.