Optimum Conditions for Oleuropein Extraction from Olive Leaves
In this study the effect of extraction solvent (type, composition, pH, and temperature), and the extraction method (maceration and soxhlet) on the amount of oleuropein extracted from olive leaves obtained from West Bank /Palestine was investigated. It was found that pure solvents (100% water, 100% methanol, and 100% ethanol) are not good solvents for oleuropein extraction, while mixtures of the solvents (methanol/water and ethanol/water) gave higher oleuropein content. It was found that 80% ethanol give the highest oleuropein content followed by 20% acetonitrile. Temperature of extraction was found to have a significant effect on the oleuropein content where higher temperature gave higher oleuropein content. It was found also that the amount of oleuropein extracted decreases with increase in pH where highest amount was obtained at pH 3. Soxhlet extraction was found to give higher oleuropein content compared to maceration method.
Oleuropein , extraction , olive leaves , maceration , soxhlet