Oxidative stability of sunflower oil enriched with ethyl acetate extracts from olive mill by-products during oxidation tests and frying

Authors : Deniz Günal Köroğlu, Semra Turan

Pages : 682-696

Doi:10.29050/harranziraat.1767927

View : 54 | Download : 213

Publication Date : 2025-12-17

Article Type : Research Paper

Abstract :This study evaluated the phenolic composition and antioxidant capacity of ethyl acetate extracts from olive mill wastewater (OMW) and olive pomace (OP), and their effects on the oxidative stability of sunflower oil. OP extract showed higher total phenolic content (263.68 mg g-1) and antioxidant activity (DPPH: 294.2 mg TE g-1; FRAP: 494.6 mg TE g-1) than OMW. Both extracts delayed oxidation in triacylglycerol (TAG) systems, though OP exhibited a pro-oxidant effect at higher concentrations. Rancimat and oxidation tests revealed that extracts partially protected oils from primary and secondary oxidation. However, prolonged heating and frying led to increased oxidation markers (K232, K270, p-AV), with OP-supplemented oils showing greater degradation at later stages. Compared to controls, OMW extract showed more consistent protection, especially in early stages. These findings suggest that OP and OMW extracts can enhance oil stability, but their protective effects diminish with extended thermal exposure.
Keywords : Fenolik bileşikler, termal bozunma, doğal antioksidanlar, lipid peroksidasyonu.

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