Development of electrochemical and chromatographic methods for the determination of phenolic compounds in table olive, olive oil and olive leaves

In this study, it is aimed to develop electrochemical and chromatographic methods for the determination of phenolic compounds in table olive, olive oil and olive leaves. There is a rising interest in natural antioxidants as bioactive components of foods. Olive (Olea europaea L.) is quite abundant in terms of phenolic compounds which are antioxidant sources together with fruit, oil and leaf. On the other hand, the olive tree grows abundantly in our country thanks to the geographical location of our country and its climate characteristics. Therefore, it is important to develop analytical methods for the quantitative determination of phenolic compounds in table olive, olive oil and olive leaves, which are excellent antioxidant resources and have significant commercial value for our country. Oleuropein, a powerful antioxidant, is found only in plants belonging to the oleaceae family. In present study, a multi-walled carbon nanotube modified glassy carbon electrode was proposed to prepare an electrochemical sensing platform for the determination of oleuropein. Compared to the bare glassy carbon electrode, the oxidation peak current of oleuropein increased about 340 times at the modified electrode. The proposed technique was validated and the validated method was successfully applied to the determination of oleuropein in an olive leaf extract. The results obtained were in agreement with those obtained by LC-ESI-MS/MS. Moreover a simple method was validated for the analysis of 31 phenolic compounds using LC-ESI-MS/MS. Analytical properties of the validated method was satisfied the routine analysis of phenolic compounds in olive leaves samples.