Supercritical carbon dioxide extraction of lipids from <i>Pythium irregulare</i>

Abstract

Abstract Lipids that contain polyunsaturated fatty acids (PUFA) have therapeutic value. PUFA, however, degrade in high‐temperature, oxygen‐rich conditions typical of conventional hot solvent‐extraction and distillation methods. Supercritical CO 2 extraction was chosen as an alternative method to recover these valuable compounds from the lower fungus, Pythium irregulare . Freeze‐dried biomass was subjected to an aqueous phase and placed into a flow‐through extraction apparatus. Extraction of oil from this biomass showed some success for moisture contents as high as 30% (wet basis). The addition of a novel CO 2 ‐philic surfactant to the wet biomass with moisture contents as high as 95% (wet basis) increased the extraction rate of fungal oil by more than an order of magnitude. For tests with extraction times of 5 to 6 h, data for the diffusion‐controlled region were modeled with an analytical solution to Fick's second law. Equilibrium data were also obtained for the fungal oil at two isotherms (40 and 60°C) over a pressure range of 13.7 to 27.5 MPa.