Supercritical carbon dioxide extraction of lipids from Pythium irregulare

Abstract

AbstractLipids 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 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 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 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 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.