Pulsed electric field assisted extraction of nutritionally valuable compounds from microalgae Nannochloropsis spp. using the binary mixture of organic solvents and water

Abstract

This work studies the potential of the pulsed electric field (PEF) assisted extraction of nutritionally valuable compounds from microalgae Nannochloropsis spp. using the binary mixture of organic solvents (dimethyl sulfoxide, DMSO and ethanol, EtOH) and water. The one-stage (EI) and two stage (EII) extraction procedures were compared. The procedure EI included the common extraction using the binary mixtures. Two stage (EII) extraction procedure involved PEF-treatment (20 kV/cm) of microalgae suspension (1% wt.) and extraction in water as the first step. The second step included the common extraction using the binary mixtures. The effects of extraction procedure and concentration of organic solvents in water on extraction of total chlorophylls, carotenoids, proteins, phenolic compounds and value of antioxidant capacity, TEAC, were analyzed. The proposed two stage PEF-assisted procedure allowed also effective extraction in less concentrated mixtures of organic solvents with water. Pre-treatment by pulsed electric field PEF) allowed highly selective extraction of different nutrients from microalgae biomass. The combination of PEF and solvent extraction in the binary mixture of organic solvents (dimethyl sulfoxide, DMSO and ethanol (EtOH)) and water allowed reaching of the high level of extraction pigments and non-degraded proteins. The obtained data can be useful for optimization of the concentration organic solvents in industrial extraction processes.