Optimization of essential oil supercritical extraction from Algerian Myrtus communis L. leaves using response surface methodology

The present work deals with the application of the supercritical fluid extraction process to extract essential oils from the leaves of an Algerian myrtle plant (Myrtus communis L.). Using the surface response methodology, an optimization of the extraction recovery was carried out, varying the pressure in the range of [10-30 MPa], the temperature within [308-323 K], a solvent flow rate fixed at 0.42 kg h(-1) and a mean particle diameter equal to 0.5 mm or less than 0.315 mm. The maximum value of essential oil recovery relative to the initial mass of leaf powder was 4.89 wt%, and was obtained when the SC-CO2 extraction was carried out under 313 K, 30 MPa and with a particle diameter less than 0.315 mm. A second-order polynomial expression was used to express the oil recovery. The calculated mass of recovered oil using the response surface methodology was very close to the experimental value, confirming the reliability of this technique. (C) 2013 Elsevier B.V. All rights reserved.