Recovery of Functional Pigments from four Different Species of Microalgae

In the present work, four species of microalgae: Spirulina platensis (SP), Chlorella vulgaris (CV), Haematococcus pluvialis (HP), and the diatom Phaeodactylum tricornutum (PT) were selected as raw materials for the recovery of multifunctional extracts. Ultrasonic assisted extraction (UAE) using different solvents was applied under specific optimized conditions. Organic solvents such as hexane, acetone and ethanol, as well as food grade solvents, such as limonene, MCT oil, soybean oil and phosphate buffer (pH= 7) were used. The total carotenoid, β-carotene and chlorophyll a content in the extracts was determined for all species using UV-Vis spectrometry. Moreover, in the case of SP the phycocyanin content was also measured. The extracts were evaluated regarding their antiradical activity using the DPPH method. Taking into consideration the nature of the solvent used and the total pigment content, acetone and ethanol can be replaced by limonene for the extraction of total carotenoids from HP and PT. For the extraction of phycocyanin from SP, water was considered the most efficient solvent. Ethanol extracts of CV were found rich in β-carotene. The DPPH assay revealed that HP and PT biomass exhibited the highest antiradical activity which can be recovered using suitable solvents.