Supercritical carbon dioxide extraction of phospholipids from dried egg yolk without organic modifier

Phospholipids (PL) were successfully extracted from dried egg yolk by using neat supercritical carbon dioxide (SC-CO2) on a microscale. The spray-dried egg yolk powder was extracted with SC-CO2 at a density of 1.06 g/ml (517 bar, 40°C), which was the maximum of density achievable with the apparatus. The extraction yield obtained by SC-CO2 (67 g of extract per 100 g of sample) can be compared with the conventional Bligh and Dyer extraction method (63 g of extract per 100 g of sample), which involves a chloroform/methanol/water mixture as an extraction solvent. The solvent extract contained 29% of PL, while the neat SC-CO2 extract consisted of 26% PL. HPLC analysis coupled with an evaporative light scattering detector (ELSD) showed no significant selectivity in the SC-CO2 extraction of the PL components. The extraction with neat SC-CO2 appears to be a valid alternative for the extraction of PL for analytical purpose.