Kinetics of supercritical CO2 extraction of bioactive oil from microalfa Spirulina platensis.

Microalgae are recognised as an important renewable source of bioactive lipids with a high proportion of polynsaturated fatty acids, wich have been shown to be effective in preventing or treating several diseases. For the extraction of oil from microalgae, supercritical CO2 (ScCO2) is regarded with interest being safer than hexane and offering a negligible environmental impact, a shorter extraction time and a high quality final product. In such a contest a mathematical model, able to describe the kinetics of a ScCO2 extraction process, was applied to the recovery of oil from the cyanobacterium Spirulina (Arthrospira) platensis, characterised by a particularly high content in gamma-linolenic acid. The kinetic model, wich allows the optimisation of working parameters and the determination of process yields, is reported together with the experimental protocol followed and the results obtained.