Effect of enzymatic hydrolysis on the extractability of phospholipids from leftover egg yolk using supercritical CO2

Supercritical carbon dioxide (SC-CO2) has been applied as a “green” solvent for phospholipids (PL) extraction from egg yolk but with limited success due to low extraction yield and purity. This study investigated a combination of proteolytic and lipolytic enzyme treatments on the extractability of PL using SC-CO2 from the leftover yolk after IgY extraction. The effects of enzymatic treatments on the recovery and purity of PC from leftover yolk using SC-CO2 in the presence of 8% (mole %) ethanol as co-solvent were studied at 48.3 MPa, 70 °C, and CO2 flow rate of 1 l/min (at ambient conditions). The average recovery and purity of PC extracted from the cream obtained after enzymatic treatment were 94% and 57%, in comparison to 47% and 47%, and 40% and 75% for dry yolk and pellet, respectively. These results indicated that enzymatic treatment had a great impact on increasing the extractability of PC from egg yolk.