SUPERCRITICAL CARBON DIOXIDE EXTRACTION OF LIPIDS FROM SKELETONEMA COSTATUM
Oils present in microalgae are of specific interest due to the rich content of polyunsaturated fatty acids. The technical feasibility of extracting oils from freeze-dried microalgae with supercritical CO2 was studied. Different extraction pressures between 17 and 31 MPa were attempted. Supercritical extracted oils and remaining lipids were analyzed by gas and thin layer chromatography. Effects of phospholipids present in microalgae on the extraction yield and the difference in fatty acid profiles from two and three week old cultures were also topics of specific interest.
Solubility data indicated no difference in extraction yields between extractions at 24 and 31 MPa. Enzymatic treatment of the samples increased the yield of oils extracted with supercritical CO2. Three-week-old cultures exhibited higher amounts of total lipids. But two-week-old cultures contained a greater variety of polyunsaturated fatty acids.