Integrated hierarchical assembly of egg white proteins into nanoparticle-nanofiber composites for improved interfacial behavior and foam stabilization

Egg white proteins (EWP) are widely used in aerated food systems but are limited by disordered thermal aggregation and weak interfacial films during processing. In this study, an integrated hierarchical assembly strategy was developed under near-neutral conditions through sequential succinylation, mild enzymatic hydrolysis, and short-time thermal induction to promote the formation of nanoparticle-nanofiber (NPs-NFs) composite structures. Succinylation provided a favorable electrostatic basis for protein conformational rearrangement, while enzymatic hydrolysis and thermal induction promoted conformational evolution toward β-sheet-enriched structures. Spectroscopic and microscopic analyses supported a transition from disordered aggregation toward ordered self-assembly and confirmed the stable coexistence of NPs and NFs. The assembled system exhibited enhanced interfacial adsorption behavior and interfacial elasticity, accompanied by improved foaming capacity and foam stability, which were further reflected by increased specific volume and a more uniform pore structure in a proof-of-concept bread model. Overall, this study provides an effective strategy for regulating the hierarchical assembly and interfacial functionality of egg white proteins under mild conditions and offers new insights into the interfacial structure design and functional optimization of protein-based hydrocolloids for aerated food applications.