Analysis of the cascade effect-based response of ovomucin to CO₂ mass transfer across the eggshell

In this study, eggs were treated with Paraffin and NaHCO₃ to alter CO₂ mass transfer rates by modulating eggshell structure to elucidate the cascade effects of CO₂ mass transfer regulation on egg quality in terms of ovomucin response. Results indicate that NaHCO₃ treatment increased eggshell porosity and reduced its effective thickness, accelerating CO₂ mass transfer and egg respiration. As a consequence, the pH of the egg white rose rapidly from 8.4 to 9.36, leading to a significant decrease in the Haugh unit, protein index, and buffering capacity of the egg white (P < 0.05). Paraffin treatment inhibited CO₂ mass transfer by sealing the micropores of the eggshell, maintaining the internal carbonate buffer equilibrium and high viscoelasticity of the egg white and significantly delaying the deterioration of egg storage quality. As the CO₂ mass transfer intensified and the storage time increased, ovomucin underwent denaturation. α₂-OVM and β-OVM were degraded during storage, with hydrophobic groups exposed and hydrogen bonds broken, causing them to gradually disintegrate from a macromolecular cross-linked network into fragmented proteins with increased solubility. Sequential cleavage of C-O-H, SO, and CO bonds in the glycan chains led to the reduced glycosylation of ovomucin and gradual detachment of sulfated glycan structures, causing the protein to become increasingly disordered and ultimately resulting in egg white thinning. This study provided a theoretical basis for elucidating the mechanisms underlying changes in egg storage quality and offers scientific insights for the future regulation of egg white quality.