Enhancing long-term stability of β-Conglycinin-based high internal phase emulsions via metal-phenolic network...

This study systematically evaluated the potential of metal phenol networks (MPNs) fabricated with different metal ions (Cu²⁺, Fe²⁺, Fe³⁺, and Co²⁺) and resveratrol (RES) for modifying β-Conglycinin (7S) and investigated the application performance of the composites in high internal phase emulsions (HIPEs). Results demonstrated that all tested metal ions could coordinate with RES on the 7S surface to form MPNs, inducing protein structural unfolding. Different types of MPNs caused varying degrees of fluorescence spectral shifts in 7S, subsequently leading to differences in emulsifying properties. Among them, 7S-Fe³⁺-MPNs composite exhibited the strongest crosslinking degree and optimal interfacial performance, reducing the interfacial tension from 8.47 mN/m to 6.91 mN/m. HIPEs prepared with this composite displayed the smallest average droplet size (60.4 ± 3.45 μm) and optimal rheological characteristics, as evidenced by smaller Lissajous curve areas. After 30 days of storage, 7S-Fe³⁺-MPNs composite stabilized HIPEs showed the most stable performance, with droplet size only slightly increasing from 60.03 ± 2.61 μm to 65.57 ± 2.97 μm, a significantly smaller change compared to other samples. This study confirms that 7S-Fe³⁺-MPNs composite can serve as highly efficient and stable emulsifiers to significantly enhance the storage stability of HIPEs, providing an innovative strategy for developing high-performance protein-based emulsion systems.