EFFECTS OF GEOGRAPHICAL ORIGIN AND CULTIVAR ON PHYTOSTEROL AND TOCOPHEROL COMPONENTS IN OLIVE (OLEA EUROPAEA L.) CULTIVARS CULTIVATED IN TURKEY

Phytosterols and tocopherols play significant roles in human health. Olive oil has been receiving special attention from consumers due to health beneficial effects. The aims of this research were to investigate the effects of geographical origin and cultivar on phytosterol and tocopherol components of twelve different cultivars of olive cultivated in Turkey. The data were collected from North Aegean, South Aegean, Marmara, East Mediterranean and Southeast Anatolia regions of Turkey in 2004-2005 and 2005-2006 growing seasons. The separation, identification and quantification of free phytosterols and tocopherols were successfully achieved using the capillary column gas-chromatographic (GC) and high performance liquid chromatographic (HPLC) methods, respectively. The analytical results showed significant differences among surveyed olive cultivars. According to the obtained results, the total phyto¬sterol content ranged between 0.911-4.629 g/kg in olive cultivars. Beta-sitosterol was the major phytosterol with high contribution to total phytosterol content followed by delta-5-avenasterol in olive oil. Beta-sitosterol content changed between 0.85-3.83 g/kg, followed by delta-5-avenasterol ranging from 0.06 to 0.81 g/kg. Regarding tocopherols, the total tocopherol content ranged between 0.040-0.347 g/kg in olive oils. Although α-tocopherol was the most abundant tocopherol fraction in olive cultivars, there was also γ-tocopherol in some cultivars. α-tocopherol content changed between 0.03-0.287 g/kg followed by γ-tocopherol ranged from 0.00 to 0.06 g/kg. Geographical region differences significantly affected the phytosterol and tocopherol contents. The total phytosterol and tocopherol contents of North Aegean region samples were higher than the other regions. This study revealed that an important variability exists for phytosterol and tocopherol contents in olive cultivars and geographical origin affected the amounts and components of the both organic compounds.