Extraction of Baccharis oil by supercritical CO2

Baccharis dracunculifolia, "Vassoura", is a shrub with spontaneous occurrence in Brazil, Uruguay, Argentina, Paraguay, and Bolivia. The Vassoura oil, valuable in the perfumery industry for its exotic aroma, presents variations in composition depending on the geographical origin and extraction process. The commercial importance is related to the oxygenated fraction content, specifically to (E)-nerolidol and spathulenol. In this work we study the dependence of the Vassoura oil composition, obtained by supercritical CO2 (SCCO2) extraction, with the following parameters: pressure, temperature, SCCO2 flow, equilibrium, and extraction times. The flexibility of the extraction process using SCCO2 allowed one to study the Vassoura oil composition as a function of the extraction parameters. Higher concentrations of (E)-nerolidol and spathulenol were obtained in the following experimental conditions: pressure, 10 MPa; temperature, 323.15 K; equilibrium time, 10 min; extraction time, 20 min; SCCO2 flow, 1.0 mL/min. The results were compared with those obtained by hydrodistillation in laboratory conditions. The evaluation of the composition for each extract was performed by gas chromatography and gas chromatography-mass spectrometry.