Exploring deep eutectic solvents for enhanced extraction of bio-active compounds from microalgae biomass

Microalgae biomass contains proteins, polysaccharides, carotenoids, phenolic compounds, vitamins, minerals, and other valuable compounds. In the extraction process of useful intracellular products from biomass, deep eutectic solvents (DESs) offer several advantages as an alternative to organic solvents. This study used deep eutectic solvents as extraction media to obtain bio-active compounds from freeze-dried microalgae biomass. This study aimed to evaluate the effect of two different DESs (Choline chloride: acetic acid (1:2) (CCA) and Choline chloride: urea (1:2) (CCU)) on the extraction of lipids, carotenoids, proteins, phenolic compounds, and carbohydrates from different microalgae biomass including Schizochytrium sp., Chlorella vulgaris, Scenedesmus protuberans and Neochloris texensis. The best results were obtained as follows: proteins from CCA-N. texensis (28.99 mg/g DW), carotenoids from CCA-S. protuberans (33.55 mg/g DW), phenolics from CCA-S. protuberans (33.44 mg GAE/g DW), carbohydrates from CCA-S. protuberans (18.32 mg/g DW), and lipids (the treated biomass pellets) from CCU-N. texensis (18.3 %). UV-spectrophotometry, LC–MS/MS, and GC–MS were used to analyse the carotenoid, phenolic, and lipid content, respectively.