EVALUATION OF ANTIOXIDANT EFFICIENCY OF POTATO AND ORANGE PEEL AND APPLE POMACE EXTRACTS IN SUNFLOWER OIL

In this study, potato peel (PPE), orange peel (OPE) and apple pomace (APE) ethanolic extracts were used as natural antioxidants in sunflower oil and their antioxidant activity was evaluated during 45 days storage at 40 degrees C. The peroxide value (POV), free fatty acid (FFA) and iodine values (IV) of oil samples were determined and the results were compared to the control sample and butylated hydroxytoluene (BHT), a synthetic antioxidant. After storage sunflower oil containing 1,500 ppm APE showed lower POVs (123.85 meqO(2)/kg oil) among the natural extracts than the control sample (140.82 meqO(2)/kg oil). The lowest POV was observed in the sample containing BHT (93.11 meqO(2)/kg oil). The FFA values of the control sample were determined in the range of 0.16-0.28% during storage but samples containing natural extracts showed lower FFA values. The IVs of samples decreased with increasing storage time because of oxidation. The addition of natural extract inhibited the decrease in IV. These results showed that PPE, OPE and APEs have strong antioxidant activity and can be used as a natural antioxidant agent for the inhibition of deteriorative oxidation in vegetable oils or other food products.