Supercritical fluid extraction of wormwood (Artemisia absinthium L.)

The objective of the work was to optimize the extraction of wormwood oil by supercritical fluid extraction (SFE) of growth-controlled plant material. Different extraction conditions, two growth techniques and various crops were tested and the evolution of the extracted oil composition was screened chromatographically. A comparison with conventional techniques such as hydrodistillation (HD) or organic solvent extraction (OSE) was also presented. Particularly, six CO2 densities ranging from 285.0 kg/m3 to 819.5 kg/m3 were studied in the range of 9.0–18.0 MPa and 40–50 °C. A systematic study was carried out with plant material from 2005, while SFE of 2006, 2008 and aeroponically grown crops was performed for comparative purposes. The effect of ethanol as a modifier of the supercritical fluid extraction was also studied. The major compounds found in the SFE extracts as well as in the HD essential oils were Z-epoxyocimene, chrysanthenol and chrysanthenyl acetate. A model based on mass transfer equations, the Sovová model, was successfully applied to correlate the experimental data.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Supercritical fluid extraction of growth-controlled Artemisia absinthium L. optimized. ▶ Modelling of the extraction results carried out with Sovová model. ▶ Comparison with traditional extraction techniques achieved. ▶ Yields and composition of all the extracts evaluated.