As the aromatic plant contains a high level of moisture, the water content of samples during extraction has been found to be a critical parameter while the particle size may affect mass transfer (Park et al., 2007). Both these parameters, together with extraction time, pressure and temperature, are important factors in extracting oil. However, the pre-treatment and extraction methods used may significantly affect (partially or totally) the quality of a product (Ratti, 2001; Arslan and Musa Ozcan, 2008).