Simultaneous extraction of lipids and minor lipids from microalga (Nannochloropsis gaditana) and rapeseed (Brassica napus) using supercritical carbon dioxide

Supercritical extraction with CO2 from a substrate composed of Nanochloropsis gaditana and cold-pressed rape-seed was studied to increase the extraction yield of oil, carotenoids, tocopherols, chlorophylls and antioxidant capacity. The independent variables were temperature (37-53 degrees C), CO2 density (885-935 kg CO2/m3) and specific solvent consumption (14-34 kg CO2/kg dry substrate). The optimal conditions for the extraction of oils and minor lipids were determined using the response surface methodology. Specific solvent consumption was the factor with the greatest effect. The oil extraction correlated positively with the extraction of carotenoids (p <= 0.01), tocopherols (p <= 0.01), chlorophylls (p <= 0.01), and antioxidant capacity (p <= 0.05). The co-extraction of oil promotes greater solubility of the minor lipids and increases their extraction. The antioxidant capacity correlated positively with the extraction of carotenoids (p <= 0.01), tocopherols (p <= 0.01) and chlorophylls (p <= 0.05).