Lysozyme "self-sacrificing" quenching reactive oxygen species blocks egg white protein oxidation and dilution degradation.

This study explored the mechanism by which lysozyme (LYZ) actively quenched reactive oxygen species (ROS) to inhibit egg white protein (EWP) oxidation. By depleting/replenishing LYZ in EWP systems, we evaluated EWP stability, oxidation degree, microstructure, and conformational changes during storage. Results showed that compared to the control group with significantly reduced LYZ activity, 0.1-0.5 % LYZ replenishment maintained stable LYZ activity and significantly decreased ROS production by 15.71 % and 95.36 %, respectively. LYZ protected EWP via side-chain reducing amino acids to disrupt ROS chain reactions, promoting storage stability, evidenced by uniform average particle size and negligible changes in zeta-potential and apparent viscosity. LYZ mitigated ROS-induced damage to α-helix and β-sheet structures, hindering surface amino acid rearrangement and hydrogen bond network disruption. Notably, 0.5 % LYZ increased α-helix content from 29.24 % to 32.17 %. Thus, LYZ protected EWP from oxidation through "self-sacrificial" ROS scavenging, providing a scientific basis for EWP storage stability regulation.