Investigating the influence mechanism of interfacial protein and lipid changes on the foam properties of whole egg liquid

Abstract

The whole egg liquid (WEL) is rich in proteins and lipids, leading to a complex group of molecules adsorbed at the interface. Current research had mostly focused on the impact of WEL components on the texture of products. However, there had been limited exploration of the interactions and stability mechanisms of components adsorbed at the interface. This study investigated the changes in the interfacial components of WEL foam over time and the effects of these on foam stability. It was found that the WEL foam had less change in foam size at 25 min. The study employed SDS-PAGE to identify ovalbumin (45 kDa), lysozyme (14 kDa), and ovomucoid (28 kDa) as the major proteins adsorbed. Subsequently, by measuring the interfacial lipid components, it was observed that the content of free triglycerides increased to 19.85 mmol/g at 35 min. Combined with CLSM, it was confirmed that low-density lipoproteins caused the outflow of neutral lipids after unfolding at the interface. Furthermore, the analysis by interfacial dilatation rheology revealed that the foam interfacial complex modulus was the highest (52.74 mN/m) at 25 min, proving that protein stabilized the foam by forming a rigid interfacial film. However, the outflow of neutral lipids led to protein detachment from the interface, disrupting the network structure and ultimately causing foam collapse. This study elucidated the relationship between the WEL foam stabilization mechanism and changes in interfacial components. It laid the theoretical foundation for further analyzing the impact of egg yolk lipids on the interfacial protein network structure.