The determination of the antioxidant activity of gemlik and halhali olives grown in Hatay

In this study, the antioxidant activity of natural phenolic extracts obtained from Gemlik and Halhalı olive variety grown in Hatay were investigated and the activity was compared to that of synthetic antioxidant which is BHT. Extraction of phenolic compounds from olive samples and the following analyses were done in Cukurova University Food Engineering Labs. Total phenolic contents of olives were found for first and last harvested Gemlik variety as 278,5 ve 206,5 mg/100g respectively and for Halhalı variety 314,8 and 288,9 mg/100g CAE (Caffeic Acid Equivalent) respectively. When the antioxidant effects of phenolic extracts of Gemlik and Halhalı compared to BHT against DPPH; antioxidant effects of both olive extracts were beter or similar to that of BHT and the activity of first harvested Halhalı and Final harvested Gemlik were the most effective antioxidants on scavenging DPPH radicals at 60 minutes. Antioxidant activities of phenolic extracts which were obtained from Gemlik and Halhalı olives and BHT were also evaluated olive oil and sunflower oil-in-water emulsions. The antioxidants effect of the olive extracts at 100 and 200 ppm were less than BHT in olive oil stored at 60 oC and the activity of the was even less than BHT at the beginning of oxidation and the extracts and BHT showed prooxidant effect in sunflower oil emulsions at the end of the oxidation at 60 oC.