Investigations of foaming, interfacial and structural properties of dispersions, batters and cakes formed by industrial yolk-contaminated egg white protein

The aim of this study was to describe the foaming properties of egg white protein systems in the presence of egg yolk in varying percentages (0–1, wt%) from an industrial “contamination” view, and to investigate the relationship among their dispersions, batters and cakes in detail. Foaming properties of dispersions, likely the most vital factors determining the quality of final products, were highly correlated with the specific density of batters and specific volume of cakes. To better understand the problem, their effects on interfacial (apparent viscosity, surface tension, size and zeta potential) and structural (optical micrographs, mean bubble sizes and cake slices) properties were also investigated. Results revealed that the interfacial properties of sample dispersions exhibited high correlations with their foaming and structural properties. Rheological characteristics of batters showed higher G′ could be reached during heating with less egg yolk (<0.2, wt%), whereas higher concentrations of egg yolk (0.5–1, wt%) had negative effect on overrun, specific volume and cross-sections. Our results indicated that the quality of cakes can be reflected by the interfacial properties of protein dispersions and the structural properties of cake batters. In addition, our study has supplied a fundamental approach for food industrial applications (such as baked goods) based on egg white to achieve optimal properties of cakes.