Supercritical CO2 extraction of the main constituents of lovage (Levisticum officinale Koch.) essential oil in model systems and overground botanicalparts of the plant

The effect of various fluid CO2 parameters on the extraction process of sep arate flavor compounds and essential oil of lovage was investigated in the present study. Model systems and lovage leaves, stems and seeds were used f or this purpose. It was found that the solubility of alpha-terpinyl acetate depends on the CO2 pressure and extraction temperature. This compound was more soluble at pressures of 200-350 bar as compared with pressures of 80-1 50 bar. The solubility of 3-n-propylidene phthalide was more dependent on t he CO2 pressure and extraction temperature than the solubility of alpha-ter pinyl acetate. 3-n-Propylidene phthalide was almost insoluble in CO2 at 80 bar and 50 degrees C, and finite solubility of this compound was obtained o nly after increasing the pressure up to 150 bar. This investigation showed that the extraction process from the model matrix is rather complex and can not be predicted from the solubility data for each separate constituent. Th e percentage content of the main constituents in the extracts varied over a wide range depending on their ratio in the initial mixture. By using a sol vent circulating system with two separators operating at different paramete rs, it was possible to obtain a phthalide enriched fraction both from the m odel matrix (prepared on celite) and raw plant material (leaves + stems and seeds). (C) 1999 Elsevier Science B.V. All rights reserved.