Tannic acid coordination assembly enhances the interfacial properties of salted egg white gel particles

Tannic acid (TA) has attracted the attention of researchers as a promising organic ligand capable of forming metal-organic coordination networks with various metal ions at interfaces to impact surface properties. In this study, we innovatively reported a self-assembly method for surface decoration by depositing TA/Fe³⁺ coatings on the surface of desalted duck egg white nanoparticles (DEWN), further studying the oil/water interfacial properties of the modified particles. The results showed that the ratio and concentration of TA to Fe³⁺ could modulate interfacial properties. The modified DEWN has low interfacial tension, with TFe2 having near-neutral wettability (θ_o/w ~ 90°) and stabilizing emulsions for over 60 days. Moreover, the emulsions stabilized by TFe1 and TFe2 formed stronger gel structures with better thixotropic recovery (98.82 % and 89.26 %). After further increasing the oil phase ratio, the increased layer assembly concentration improved the stability of the oil phase and formed a dense gel mesh structure. The effects of temperature and salt ion concentration on the emulsion were investigated under optimum conditions, both of which showed good stability. Overall, our research not only highlighted straightforward strategies for preparing emulsions with higher stability using green and sustainable raw materials, but also broadened the range of applications for metal-phenol decoration.