Extraction and Characterization of the Phenolic Compounds from Leaves of Olea Europaea L. via Ple

Oleuropein is the predominant phenolic compound in olive leaves. It presents high antioxidant and anti-inflammatory activities and has antimicrobial action. The objective of this study was to extract the phenolic compounds from dried olive leaves using pressurized ethanol in a continuous flow and characterize them. The flow rate (0.5 to 1.0 mL min-1), temperature (30 to 60 °C) and pressure (10 to 20 MPa) were the operational parameters. The results showed that the temperature was a significant factor in the yield of the extracts, with higher yields at the highest temperature. The oleuropein content in the extracts ranged from 80.5 to 82.9 mg g-1, and the extract presented different classes of compounds. The total phenolic components were in the range of 10.5 to 12.8 mg GAE g-1 of extract. The best condition to obtain an extract with the highest yield and total phenolic compounds, and suitable oleuropein content and antioxidant capacity was 60 °C, 10 MPa and 0.5 mL min-1.