Microalgae solvent extraction

An integrated process for highly purified PUFAs from microalgae has been developed at the University of Almeria (Molina Grima et al., 1996). The process basically employs solvent extraction, phase separation, urea adduction of fatty acids, and chromatographic separation of PUFA rich fraction the process is summarized in Figure 26.1. The same is applicable to recovery of PUFA rich lipid fractions from seaweeds as well. 

It is possible to obtain lipids from microalgae by conventional solvent extraction. However, extraction with supercritical (SC) CO, is emerging as a potential alternative to obtain lipids from natural sources (13-19). 

Accelerated Solvent Extraction of Functional Compounds from Microalgae Spirulina platensis... 

Grierson S, StrezovV, Bray S, Mummacari R, Danh LT, Foster N. Assessment of bio-oil extraction from Tetrasehnis chui microalgae comparing supercritical CO2, solvent extraction, and thermal processing. Energy Fuels 2012 26 248. 

In this regard, ethyl lactate is being studied as exlraetion solvent of food compounds. Several reported potential applications are related with the exlraetion of earotenoids fi om different plant matrix, " with extraetion of eaffeine from green eoffee beans and green tea leaves, the fractionation of edible oil eompounds (squalene and toeopherol ), the extraction of sclareol fi om the leaves of Salvia sclarea Lamiaeeae, the extraetion of y-linolenic acid from Spirulina microalgae the extraction of phytosterols fi om eom fiber and the extraetion of the essential oil from different speeies of thyme. ... 

That many chemical substances are not soluble in sc carbon dioxide permits selective extraction.100 It is often used with foods, for which it eliminates the possibility of leaving toxic residues of solvents such as methylene chloride. It also avoids the hydrolysis that might occur when esters (for flavors or fragrances) are recovered by steam distillation. It has been used to extract the flavor from hops, the caffeine from coffee, fat and cholesterol from foods,101 pecan oil,102 lavender oil (for which hydrolysis of linalyl acetate could occur in steam distillation), 103 ginseng (from which it does not extract pesticide residues),104 ginger,105 microalgae,106 cooked chicken,107 ethanol from cider,108 and many others. One method used with aromas and con-... 

We studied the extraction of lipids from algae (Isochrysis galbana Parke) to verify the possibility to enrich EPA, DHA or other omega-3 fatty acids for healthy products or pharmaceutical application (35). We found that the SFs allow the extraction of lipids from microalgae with interesting fatty acid composition and good extraction yield in comparison with traditional solvents. 

In a previous work, we studied the possibility of extracting antioxidants from microalgae Spirulina platensis using ASE with different solvents (33-34). Likewise, other authors have studied the carotenoids extraction from microalgae Haematococcus pluvialis and Dunaliella salina using ethanol as solvent and ASE (35). 

In conclusion, in this work we demonstrate the excellent capabilities of using ASE to extract compounds with antioxidant activity from natural sources as rosemary leaves and the microalga Spirulina platemis. ASE shows several advantages compared with traditional extraction processes such as 1) it is faster (IS min vs 2-24h in traditional extraction procedures) 2) it has less solvent volume consumption (13 ml vs 30>S00 mL/lOg) 3) it is more efficient (less dependant on matrix) and 4) it is automatic and allows sequential extraction of samples. The use of in-vitro assays and CE coupled to both, DAD and ESI-MS allows obtaining information about the biological and chemical properties of the ASE extracts. 

Pulse electric field is a technique which uses brief pulses of a strong electric field to perforate the cell wall or membrane. This method has already been applied on microalgae for lipid extraction. Zbinden et al. utilized PEF as a process intensification strategy to enhance lipid extraction from Ankistrodesmus falcatus wet biomass using a green solvent, ethyl acetate. 2 In another study, application of PEF on Auxenochlorella protothecoi-des led to a spontaneous release of intracellular products. ... 

Zbinden MDA, Sturm BSM, Nord RD, Carey WJ, Moore D, Shinogle H, et al. Pulsed electric field (PEF) as an intensification pretreatment for greener solvent lipid extraction from microalgae. Biotechnol Bioeng 2013 110 1065. 

Liau B-C, Shen C-T, Liang F-P, Hong S-E, Hsu S-L, JongT-T, et al. Supercritical fluids extraction and anti-solvent purification of carotenoids from microalgae and associated bioactivity. J Supercrit Fluids 2010 55 169. 

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