Supercritical fluid extraction of carotenoids and chlorophyll a from Synechococcus sp.

Supercritical carbon dioxide extraction of carotenoids and chlorophylls is an alternative to solvent extraction because it provides a high-speed extraction process with a simple purification stage. In the study described here, carotenoid and chlorophyll extraction with supercritical CO2 was explored using dry biomass from a marine cyanobacterium Synechococcus sp. as the raw material. The operation conditions were as follows: pressures of 100, 200, 300, 400 and 500 bar, temperatures of 40 , 50 and 60 °C. Analysis of the extracts was performed by measuring the absorbance and by using an empirical correlation.The results demonstrate that the highest extraction yield of total carotenoids is obtained operating at a pressure of 300 bar and a temperature of 50 °C. The most appropriate operating conditions to obtain the best yield in the extraction of chlorophyll a are 500 bar and 60 °C.The highest carotenoids/chlorophylls (Carot/Chlor) ratio is obtained at 200 bar and 60 °C. Under these operating conditions a higher selectivity is obtained and this should facilitate the separation and purification of the two extracted pigments.