Comparison of oxidation stability of virgin olive oils from different locations of Turkey

Ten kinds of virgin olive oil of two major cultivars (Ayvalik and Memecik) produced in several areas of Turkey (Bayindir, Edremit, Ortaklar, Burhaniye, Ezine, Tire, Havran, Ayvalik, Altinoluk, and Kucukkuyu) were analysed. The quality characteristics, fatty acid composition, total phenol, and o-diphenol content of the samples were determined. Oxidative stability and free radical scavenging activity were determined using Rancimat test, Schaal oven test, and DPPH method. It was found that while Memecik oil from Ortaklar demonstrated the strongest oxidative stability, Ayvalik oil from Ezine had the lowest oxidative stability among the samples. Fatty acid composition and especially oleic acid/linoleic acid ratio was previously defined as a parameter that can help distinguish cultivars from one another; however, this study proved that total phenol, especially o-diphenol content of the oil, has the strongest effect on oxidative stability compared to other factors including fatty acid composition.