Supercritical fluid extraction from microalgae with high content of LC-PUFAs. A case of study: Sc-CO2 oil extraction from Schizochytrium sp

Among the different kinds of marine sources, microalgae are a potential source of triacylglycerides which may contain high amounts of LC-PUFAs such as ω-3 fatty acids EPA and DHA. For the extraction of oil from microalgae, Sc-CO2 is regarded with interest being safer than hexane and offering a negligible environmental impact, a short extraction time and a petroleum-free final product. In such a contest, a mathematical model able to describe the kinetics of an SFE process was applied to the extraction with Sc-CO2 of lipids from Schizochytrium sp., a marine microalga characterized by a particularly high content of LC-PUFAs, and a very high concentration of DHA. The aim of this paper was to examine the effect of operating conditions on the kinetics of the SFE, on process yields and on the fatty acid composition of lipid extracts, also in comparison with the conventional extraction by percolation with n-hexane.