Studies on Supercritical CO2 Extraction-molecular Distillation of Essential Oil from Clove(Eugenia caryophyllata Thunb.)Bud

Clove(Eugenia caryophyllata Thunb.)bud was extracted with supercritical CO2 extraction (SCDE) and then refined with molecular distillation (MD). The refined clove oil was analyzed by GC-MS. The optimum condition of SCDE for clove oil was:extraction temperature 45℃, pressure 12 MPa, and separating temperature 50℃. The extaction yield was 21.04%. Twenty-two components in the clove oil were detected by GC-MS. The content of eugenol in clove oil refined with MD was increased from 67.55% to 68.75%. Total contents of three main components (eugenol, β-caryophyllene and eugenol acetate) obtained by SCDE-MD,hydrodistillation and organic solvent reflux methods respectively were mostly similar. The total yield of clove oil(19.18%) obtained by SCDE-MD was alsohigher than those by steam distillation(11.38%) and n-hexane extraction(17.40%). SCDE-MDhas many advantages over traditional methods, including shorter extraction time, low contents of colorants and resin.