| The effects of different organic solvent systems and supercritical CO2（SC-CO2）extraction on the yield and EPA content of microalgae oil were studied with Nannochloropsis Oceanica as the material. Response surface methodology was employed to optimize the SC-CO2 extraction conditions. The results showed that the optimal extraction process for solvent extraction was petroleum ether-acetone-ethanol (volume ratio 2∶?1∶?0.5). Under this condition, the yield of microalgae oil was 23.74%, and the EPA content accounted for 31.34%. The best co-solvent for SC-CO2 extraction was methanol, and the optimal extraction conditions were obtained as follows: extraction pressure 26 MPa, extraction temperature 48?℃ and extraction time 168 min. Under these conditions, the yield of microalgae oil was 8.34%, and EPA content reached 25.66%. GC-MS analysis results showed that the fatty acid compositions of microalgae oils extracted by two methods had no significant difference, mainly composed of polyunsaturated fatty acids. Considering the equipment cost, energy consumption and other issues, solvent extraction method had more advantage than SC-CO2. |
