Extraction and Fractionation of Lovage (Levisticum officinale Koch) FlavorComponents by Supercritical Carbon Dioxide

摘要

Sub- and supercritical CO{sub}2 extractions of lovage (Levisticum officinale Koch.) roots were carried out in order to determine the effect of CO{sub}2 parameters on the extract yield and the composition of volatile compounds. First series extractions were performed to establish the effect of CO{sub}2 pressure and temperature; second, to determine the dynamics of the ext raction at constant temperature. It was found that by varying the pressure from 80 to 300 bar and the temperature from +10°C to +55°C the best result was obtained at 50°C and 200 bar. During the second series the temperature was kept at 50°C and the extracts were collected at various stages of extraction process at the pressures from 80 to 350 bar. The extract yield considerably increased by raising the pressure from 80 to 200 bar, however, further pressure increase to 350 bar was not so efficient. The composition of volatile compounds was examined by gas chromatography and mass spectrometry. Part icular attention was focused on the content of phthalides, which are considered as key flavor compounds of lovage. Among 8 identified phthalides, cis-ligustilide was most abundant in all extracts; its content depending on extract ion parameters and process time varied in a very wide range, from 2 to 65%.