Functional food oil coloured by pigments extracted from microalgae with supercritical CO2

A functional food oil, rich in fatty acids and antioxidants, coloured with pigments (carotenoids) extracted with supercritical CO2 from the microalga Chlorella vulgaris, was produced, having in view its use in food industry (namely for derived seafood). The supercritical fluid extraction (SFE) was carried out in order to study the effect of several modifiers (oil mixed with the microalga and ethanol with the supercritical CO2), the degree of crushing of the microalga and the supercritical fluid flow rate, at a pressure of 300 bar and temperature of 40 °C. Moreover, the microalga pigments were also extracted with acetone and with vegetable oil at room and high temperature. The recovery of carotenoids was 100% with oil at room temperature for 17 h, 70% with oil at 100 °C for 30 min, 69% with supercritical CO2 at 40 °C and 300 bar. In SFE the degree of crushing strongly influenced the extraction recovery and higher pigment recoveries were obtained with well crushed biomass.The stability of soybean oil containing the extracted pigments was also evaluated (light protected) over six weeks, in terms of total carotenoid content and peroxide value. Carotenoids exhibited good preservation over the time, practically without loss. Peroxide values were stable for all extraction systems, showing only a slight increase over time.