SUPERCRITICAL CO2 EXTRACTION OF ESSENTIAL OILS AND CUTICULAR WAXES FROM PEPPERMINT LEAVES

Essential oils and cuticular waxes were extracted from peppermint leav es with supercritical carbon dioxide in a semicontinuous-flow extracto r. The effects of CO2 flow rate and pressure on the extraction rate we re studied within the how rate range of (4.1-9.8) x 10(-5) kg s(-1) an d the pressure range of 10-30 MPa. Flow rate effect indicated that the intraparticle diffusion resistance was not dominant in this process. The extraction rate of cuticular waxes increased remarkably with the p ressure, whereas that of essential oils was almost constant as compare d with cuticular waxes. The concentration of cuticular waxes at the ex it of the extractor was close to the solubility of triacontane while t hat of essential oils was much lower than the solubility of 1-menthol.