SUPERCRITICAL CO2 EXTRACTION OF EGG-YOLK - IMPACT OF TEMPERATURE AND ENTRAINER ON RESIDUAL PROTEIN

Differential scanning calorimetry (DSC) was used to monitor changes in protein conformation resulting from supercritical carbon dioxide (SC-CO2) extraction Of lipids from egg yolk. Extraction temperatures of 65-degrees-C and lower had no effect on protein conformation as indicated by similar denaturation temperatures and enthalpies of denaturation (DELTA-H). An extraction temperature of 75-degrees-C resulted in a reduction in the DELTA-H value for ovalbumin present in the egg yolk. The use of 3% methanol as an entrainer during extraction at 36 MPa and 40-degrees-C resulted in a 50% reduction in the DELTA-H value for ovalbumin. The use of high temperatures and/or entrainers during SC-CO2 extraction can result in significant protein denaturation.