Synergistic modification of ovalbumin by pH-driven and metal-phenolic networks: Development of dysphagia friendly high internal phase Pickering emulsions

Dysphagia is a common functional disorder that limits the variety of available foods. This study explored the coordination assembly of tannic acid (TA) with Fe3+ to form a metal-phenolic network (MPN) and developed ovalbumin (OVA)/MPN via a pH-driven method as a novel emulsifier to stabilize high internal phase Pickering emulsions (HIPPEs). Results indicated that, following pH-driven treatment, the OVA/MPN composite particles exhibited smaller sizes, enhanced electrostatic repulsion, and improved stability. UV-visible spectroscopy confirmed the successful assembly of MPN with OVA, while pH-driven processes facilitated MPN formation. Multi-spectral technology showed that MPN altered the intermolecular interactions and structural properties of OVA. The cooperatively modified OVA demonstrated superior interfacial wettability and emulsifying properties. Rheological studies revealed that all HIPPEs exhibited gel-like behavior and shear-thinning characteristics. HIPPEs stabilized by OVA, modified synergistically through pH-driven and MPN introduction, showed a dense network structure with higher viscosity, modulus, yield stress, and elasticity. IDDSI testing showed that HIPPEs with TA below 8 mg/mL had low-risk swallowing characteristics, while those with 12 mg/mL exhibited reduced rheological performance and failed the Level 4 dysphagia test. These findings provide crucial insights for the future development of HIPPEs suitable for individuals with dysphagia.