Polyunsaturated ω-3 and ω-6 fatty acids, total carotenoids and antioxidant activity of three marine microalgae extracts obtained by supercritical CO2 and subcritical n-butane

Microalgae are one of the most promising sources for new functional food products, due to their ability to synthesize polyunsaturated fatty acids, pigments and natural antioxidants (e.g. carotenoids and phenolic compounds). The aim of this study was to compare the fatty acid composition, total carotenoids and antioxidant activity of Phaeodactylum tricornutum, Nannochloropsis oculata, and Porphyridium cruentum extracts obtained from supercritical CO2 (SC-CO2) and subcritical n-butane extraction methods SC-CO2 method was selective in extract saturated fatty acids (SFAs) for all microalgae species studied. On the other hand, subcritical n-butane was shown to be an excellent and powerful method to extract polyunsaturated fatty acids (PUFAs omega 3 + omega 6). Regarding to total carotenoids and antioxidant activity using DPPH scavenging assay a significant correlation coefficient (R-2 = 0.80) was found among the extracts independent of the extraction method tested. This indicates that carotenoid compounds might be the major contributor to the antioxidant capacities of these microalgae.