Supercritical fluid extraction of carqueja (Baccharis trimera) oil: Process parameters and composition profiles

Carqueja (Baccharis trimer a Less) is a common plant native from South America. In this work, the global yield (X0) of carqueja oil, extracted by means of supercritical CO2 at 30 and 40 °C and from 100 to 300 bar, was investigated. The maximum solvent flow rate employed was 8.33 gCO2/min, with extraction times up to 6 h. The global yields varied from 0.34 to 2.07% (w/w). Additionally, the supercritical process was compared with the organic solvent extraction in terms of yield and oil composition profile. Carqueja extracts were analyzed by gas chromatography–mass spectrometry (GC–MS) and 14 different components were identified. The mathematical models proposed by Tan and Liou [Tan, C. and Liou, D., 1989, Modeling of desorption at supercritical conditions, AIChE J, 35(6): 1029–1031], Brunner [Brunner, G., 1994, Gas Extraction: An Introduction to Fundamentals of Supercritical Fluids and the Application to Separation Processes (Springer, New York)], Sovová [Sovová, H., 1994, Rate of the vegetable oil extraction with supercritical CO2. Modelling of extraction curves, Chem Eng Sci, 49(3): 409–414] and Esquível et al. [Esquível, M.M., Bernardo-Gil, M.G. and King, M.B., 1999, Mathematical models for supercritical extraction of olive husk oil, J Supercritical Fluids, 16: 43–58] were used for the description of the kinetic aspects of the supercritical process. The modeled results showed good agreement with experimental data especially for the constant extraction rate period (CER).