Analysis of vitelline membrane proteins of fresh and stored eggs via HPLC

Abstract

 Eggs stored for up to 30 days at temperatures of 5, 10, 20 and 30°C at 60% relative humidity were investigated with regard to their protein composition. The salt-soluble protein lysozyme and the vitelline membrane outer proteins (VMO1, VMO2) were isolated from the vitelline membrane, separated via HPLC on a reversed-phase column and their content was determined in relation to membrane weight and protein content. The SDS-soluble fraction was studied using SDS electrophoresis. These investigations revealed that in eggs stored at a temperature of 20°C the amount of VMO1 and VMO2 in the salt-soluble fraction decreased during storage. Eggs stored under refrigerated conditions did not show significant changes in the salt-soluble fraction. Membrane weight and protein content of the salt-soluble fraction seemed not to be influenced by storage while the lysozyme percentage in the salt-soluble fraction increased. This leads to the conclusion that the deterioration of the vitelline membrane during storage may be related to disintegration of the proteins VMO1 and VMO2 from the membrane.