Sensory and yield response surface analysis of supercritical CO2 extracted aromatic oil from roasted coffee

The CO2 supercritical extraction of coffee oil from roasted Brazilian Coffea arabica was performed at different operational conditions. A central compositie design was then applied a 2(2) full factorial approach for two independent variables: pressure (250 to 300 bar) and temperature (50 to 90 degreesC). Five levels with four star points and two replicates at the centre point were used. A sensorial panel composed of properly trained coffee consumers tested the characteristic coffee aroma of the roasted coffee aromatic oil extracted. The sensory analysis showed that the high temperature did not affect the intensity of characteristic coffee aroma and indicated that CO2 supercritical extraction produced an extracted oil rich in coffee aroma. The yields of the extracted roasted coffee aromatic oil were analysed by the response surface analysis, as a function of the two experimental parameters. These parameters significantly affected the extraction yield. The best yield was obtained with decreases in the temperature values and pressure values at proximity of the centre point (275 bar).