Determination of antioxidant effects of Gemlik, Domat, Adana topaği and Adana local type olive leaves

In this study, the antioxidant activity of Gemlik, Domat, Adana Topağı ve Adana Yerli olive leaves were investigated and the results were compared to that of commercial olive leaf extract as well as snythetic antioxidants such as BHT and BHA. The results showed that Domat olive leaf at all harvesting time and other olive leaves at some harvesting time showed higher total phenolic contents than commercial olive leaf extract. The total phenolic content of Adana Topağı and Domat olive leaves were signifantly reduced depending on harvesting time. Values for DPPH radical scavenging activities showed that ARP values of commercial olive leaf extract were higher than other olive leaf extracts regardless of variety and harvesting time. However, the radical scavenging activity of olive leaves at some harvesting time at 100 or 200 ppm were similar to commercial olive leaf extract and higher than BHT and similar or higher than BHA . The addition of refined olive oil 100 and 200 ppm all olive leaves increased oxidative stability and caused to extracts to show better activity than commercial olive leaf extract. The activity of olive leaves were equal or better than commercial olive leaf extract but lower than that of BHT and BHA.