Supercritical fluid extraction of sunflower seed oil with CO2-ethanol mixtures

The effect of ethanol addition to supercritical carbon dioxide (SC-CO2), up to 20% on sunflower seed oil extraction over the range of 150 to 350 bars and 42 to 80 degrees C was studied. A nonrecirculating home-made bench-scale system was used as extraction equipment. The oil-SC-CO2-ethanol mixture was reduced to atmospheric pressure in a test tube, where two phases, oil and ethanol, were obtained and ethanol-saturated CO2 was liberated to the atmosphere. Results show that sunflower oil solubility in SC-CO2 greatly increases with addition of ethanol as entrainer over the whole range of pressure and temperature conditions. Some phospholipids are coextracted at levels directly proportional to the added ethanol, Moreover, a large amount of phospholipids was recovered in the ethanolic phase. Acidity of the extracted oil with ethanol as entrainer was lower than that without alcohol. Part of the free fatty acids was found in the ethanolic phase.