Extraction of fennel (Foeniculum vulgare Mill.) seeds with supercritical CO2:: Comparison with hydrodistillation

Ground fennel (Foeniculum vulgare Mill.) seeds, growing wild in Montenegro, were extracted with supercritical CO2 (SC-CO2) at a flow rate of 0.2 kg CO2/h under varying extraction conditions in order to determine yield, composition and organoleptic characteristics of extract. The extracts obtained were compared to fennel seed oil isolated by hydrodistillation. In the SC-CO2, extracts as well in the hydrodistilled oil, the major compounds were trans-anethole (68.6-75.0%) and (62.0%), methylchavicol (5.09-9.10%) and (4.90%), fenchone (8.40-14.7%) and (20.3%), respectively. With pressure varying from 80 to 150 bar and temperature varying from 40 to 57 degrees C, it was found that, for the selected herb material, the optimal conditions Of SC-CO2 extraction (high percentage of trans-anethole, with significant content of fenchone and reduced content of methylchavicol and co-extracted cuticular waxes) are: pressure, 100 bar; temperature, 40 degrees C extraction time, 120 min. Organoleptic tests confirmed that hydrodistilled oil possessed a less intense fennel seed aroma than extracts obtained by SC-CO2. (c) 2004 Elsevier Ltd. All rights reserved.