Supercritical carbon dioxide extraction of lipids from Pythium irregulare

Lipids that contain polyunsaturated fatty acids (PUFA) have therapeutic val ue. PUFA, however, degrade in high-temperature, oxygen-rich conditions typi cal of conventional hat solvent-extraction and distillation methods. Superc ritical CO2 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 e xtraction apparatus. Extraction of oil from this biomass showed some succes s for moisture contents as high as 30% (wet basis). The addition of a novel CO2-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 a n 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 t o Fick's second law. Equilibrium data were also obtained for the fungal oil at two isotherms (40 and 60 degrees C) over a pressure range of 13.7 to 27 .5 MPa.