Effect of pulsed electric fields on the main chemical components of liquid egg and stability at 4°C

Abstract

The effect of PEF on the whole liquid egg components, proteins and lipids, and the microstructure were studied and compared with pasteurisation. The effect of the refrigerated storage one week after the treatments was too studied. After all the treatments, only pasteurised samples showed water-soluble protein values significantly lower than the control and PEF treated samples, even after refrigeration. This could be related to the reinforcement of protein-protein interactions generated by the partial dcnaturalisation of proteins, observed by Cryo-SEM. Moreover, a water-soluble protein decrease was detected in the control and PEF treated samples after refrigeration, probably due to the aggregation of the egg lipoprotein during the storage. Furthermore, a slight lipolysis was observed in the control and PEF treated samples after refrigeration; but this effect was lower as higher was the PEF treatment. The study of the oxidation parameters showed an intermediate degradation of the lipids in treated samples, compared to the pasteurised eggs. These would reflect a higher microbiological stability of the PEF treated samples compared to the non-treated eggs.