Essential Oils of Taxodium distichum Winter Leaves Obtained by Supercritical Carbon Dioxide Extraction Method and Hydrodistillation

The extraction of Taxodium distichum needles was done using supercritical carbon dioxide extraction and hydrodistillation. SC CO2 extraction of T. distichum winter leaves was conducted at different pressures and temperatures using a central composite rotatable design. The optimal extraction conditions concerning the yield and α-tocopherol relative amount were determined by response surface methodology. The optimal conditions for the highest extraction yield of 3.97% were at 17.79 MPa and 62.70 °C and the highest α-tocopherol relative amount of 85.99 mg per 100 g of the plant material was at 22.07 MPa and 35.86 °C. The essential oil obtained by hydrodistillation contained 62 compounds and (-)-caryophyllene oxide was dominant (55.55%). The T. distichum essential oil obtained by SC CO2 extraction and hydrodistillation had a different composition. The desirable compounds influence the choice of the extraction method.