Mechanistic elucidation of DHPM-induced foamability enhancement in egg white protein: Structural and interfacial modifications

Egg white protein was extensively employed in the food industry owing to its exceptional foaming properties. Laboratory findings indicated that dynamic high-pressure microfluidization (DHPM) technology significantly enhanced the foaming ability and stability of egg white protein, while the underlying mechanisms remained unclear. This study elucidated the mechanism of DHPM-mediated improvement in egg white protein foaming performance through surface tension, apparent viscosity, surface hydrophobicity, particle size, zeta potential, and ultraviolet absorption spectra. Egg white proteins treated with DHPM treatment had a more uniform and smaller average particle size, with surface tension reaching its minimum (46.09 mN/m) at 6000 psi (two passes), while apparent viscosity peaked at 13,000 psi (two passes). Surface hydrophobicity of egg white protein attained its maximum value (1667.4) at 10,000 psi (three passes), representing a significant 47.88 % increase versus the control ( p < 0.05), coinciding with the maximum absolute zeta potential (10.42 mV). Following one to three homogenization passes, the UV absorption peak at 224 nm exhibited a distinct blue shift, while absorption intensity varied with increasing homogenization pressure. Pearson correlation analysis demonstrated that improvements in foaming ability and foam stability were linked to modifications in surface tension, surface hydrophobicity, and zeta potential. Therefore, the DHPM treatment significantly enhanced the foaming ability and foam stability by reducing surface tension, enhancing surface hydrophobicity, and altering the tertiary structure of egg white protein, causing denaturation, thereby reducing the molecular size and improving the solubility. These findings aimed to provide a theoretical framework and technical references for the value-added utilization of egg white protein in food applications.