Extraction of biomolecules from Spirulina platensis using non-conventional processes and harmless solvents

The aim of this work was to improve the process of biomolecule extraction from Spirulina platensis, using non-conventional processes, such as ultrasound and microwave radiation, in conjunction with solvents that are less harmful to the environment than those used in conventional procedures. The method for extracting biomolecules by ultrasound included the use of the solvents hexane, ethanol, and water for different times. For microwave-assisted extraction, the solvents used were water and solutions of Na2SO4 and NaCl, and biomolecule extraction via the method of ethanol contact was examined after water extraction. For comparison with the results obtained, the Soxhlet method was used at 80 °C for 8 h with ethanol as a solvent. The best yield of biomolecules using ultrasound was obtained with ethanol used for three cycles. In terms of microwave extraction, ethanol contact improved the extraction, but differences in the time of contact were not significant. The most effective procedure for extracting biomolecules was with water for three cycles, using ethanol-chloroform-water-Na2SO4 and ethanol as solvents in ultrasound-assisted extraction. The lipid fractions of extracts contained myristic, palmitic, stearic, oleic, and erucic acids, all of which have wide industrial applications.