Algal extracts: Technology and advances

A number of studies on the development of a variety of extraction techniques to produce algal extracts have been reported. At present, attention is paid to the production of algal extracts without resorting to toxic organic solvents or aggressive extraction conditions that could deteriorate biologically active compounds found in algal cells. In this review, we present a critical overview of novel techniques to extract biologically active compounds from algae without their degradation. We compare the advantages and disadvantages of classic and novel extraction techniques such as supercritical fluid extraction, microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction, pressurized liquid extraction. Additionally, we review the different biomass pretreatment methods. Products derived from algae are safe to plants, animals, and human. Therefore, they can be used in modern agriculture (biostimulants, bioregulators, feed additives) and in food, cosmetic, and pharmaceutical industries.