Lipid content and fatty acid profile of Nannochloropsis oculata before and after extraction with conventional solvents and/or compressed fluids

• Published in: The Journal of supercritical fluids 2016-02, Vol.108, p.89-95
• Main Authors: Baumgardt, Francis J.L., Filho, Arion Zandoná, Brandalize, Marcus V., da Costa, Dayane C., Antoniosi Filho, Nelson R., Abreu, Paulo C.O.V., Corazza, Marcos L., Ramos, Luiz Pereira
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Ethanol; Fatty acid methyl esters; Nannochloropsis oculata; Pressurized fluids; Propane
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2015.11.003

[Display omitted] •Microalga oil extraction was performed with conventional and/or compressed fluids.•Ethanol was the most efficient conventional solvent for microalga oil extraction.•Subcritical propane performed better than supercritical CO2 for oil extraction.•Extraction yields were better when ethanol was used as a co-solvent.•The use of compressed fluids reduced the amount of solvent required for extraction. The lipid content and fatty acid profile of freshly harvested Nannochloropsis oculata was characterized before and after extraction with both conventional solvents and compressed fluids. Among the conventional solvents, ethanol was the most efficient, yielding 11.33g of fatty acids methyl esters per 100g−1 of dry microalga biomass. The addition of ethanol as co-solvent at a mass ratio of 1:1 improved the extraction performance of both subcritical propane and supercritical CO2. At 200bar and 80°C, the extraction of N. oculata with propane in the presence of ethanol resulted in the best yield of 7.53g of fatty acid methyl esters per 100g of the desalted biomass. By replacing propane by carbon dioxide, this yield dropped 45.8%. However, under the conditions used in this study, both conventional and compressed fluid extractions did not remove the entirety of the microalga fatty acids, demonstrating that these processes toned to be optimized to avoid mass transfer limitations. Even so, the use of compressed fluids reduced the amount of solvent used when compared to extraction with a conventional Soxhlet apparatus.