Targeted design and controllable assembly of egg white protein complexes guided by phase behavior: Thermal stability...

This study reported on the complex coacervation behavior of ovotransferrin (OVT) and lysozyme (LYS), exploring the relationship among differential coacervation patterns and structures, thermal properties, and processing characteristics of complexes. Systematic characterization revealed that at the mixing ratio of 1:1 and pH 10, the surface charges of OVT and LYS reached neutralization, forming insoluble coacervates with maximum particle sizes (7652.7 nm) and the most stable, compact structure. However, processing-oriented experiments revealed that the application performance of the complexes did not exhibit a straightforward positive correlation with structures. Complexes at pH 4 exhibited superior foaming capacity and emulsion stability due to looser structure and smaller particle sizes (3107.0 nm). Enhanced electrostatic attraction at pH 7 promoted the formation of insoluble complexes abundant in β-turn structures (53.4% secondary structure). Increased local structural flexibility achieved balanced foam stability and enhanced emulsification properties. Spherical coacervates formed at pH 10 exhibited the highest thermal stability due to charge neutralization, albeit with poorer emulsion stability. Furthermore, molecular docking confirmed OVT-LYS complexes were primarily stabilized by electrostatic interactions and hydrogen bonds. MD simulations elucidated conformational changes during OVT-LYS binding and revealed the stability of the complex conformation. This research provided significant insights into the application of rationally designed heteroprotein complexes in fields such as food science.