Effect of extraction method and extraction solvent on recovery of phenolic compounds from olive leaves in Kemalpaşa-İzmir (Turkey): Oleuropein recovery as a case example

Oleuropein, especially in its leaves, has an important role in durability of olive tree with its protective effect against diseases and pests. In this study, oleuropein has been extracted from olive leaves by using different extraction methods. Effects of extraction solvent and the extraction method that were obtained from Kemalpaşa-İzmir, Turkey, were studied. Results showed that the proposed method and the solvent contained more amount of extracts than existing extraction methods. Efficient extraction without degradation was achieved in 2 h. It has also been found that modified superheated liquid extraction in 50:52:25 ethanol:isopropanol:water composition gave the highest recovery.