FARKLI BİTKİSEL EKSTRAKTLARIN AYÇİÇEĞİ YAĞININ OKSİDATİF STABİLİTESİ ÜZERİNE ETKİLERİ

The aim of this study was to evaluate the performance of 7 different plant extracts on prevention of sunflower oil oxidation. Sunflower oil samples enriched with different herbal extracts were subjected to accelerated oxidation conditions at 25, 50 and 75 °C for 21 days of storage. Peroxide value (PV), malondialdehyde (MAD), conjugated dien (K232) and trien (K270) values were determined initially before the storage, and at the 7th, 14th and 21st day of storage. In addition, antioxidant activities of the ingredients used as antioxidant source were analyzed by DPPH (EC50) test. PV, MAD, K232 and K270 values increased by the increase of the storage temperature during the storage period. Especially, rosemary extract (RE) was found to be as effective as sumac (SM) and nettle (NE) extracts, natural tocopherols of the refined sunflower oil, AP and BHT used as a reference antioxidant, in deferral of formation of primary oxidation products. Similarly, RE, SE and ginger (GE) extract was quite effective in deferring the formation of secondary oxidation products. It is concluded that RE, SM, NE and GE were effective in prevention of oxidation and improving the oxidative stability of sunflower oil, and thus, they may be used commercially in food industry to provide longer shelf life for edible oils and oily products.