The mechanism of glutenin-tannic acid nanoparticles in improving the storage instability of glutenin emulsion: Based on interactions, nanoparticle property, and interface property

The strong hydrophobicity of glutenin (Gln) limits its application as a food emulsifier. To address this, we hypothesized that hydrophilic tannic acid (TA) could interact with glutenin to enhance the stability of glutenin emulsions. The mechanism of Gln-TA nanoparticles in improving emulsion stability was explored through synergistic analysis of interactions, nanoparticle characteristics, and interfacial properties. These results revealed that the formation of Gln-TA nanoparticles was primarily driven by hydrogen bonding and hydrophobic interactions. The incorporation of tannic acid enhanced both the short-term and long-term stability of glutenin emulsions, though their effects and mechanisms differed significantly. Specifically, the ability of Gln-TA nanoparticles to improve short-term emulsion stability exhibited a distinct tannic acid concentration dependence. When the tannic acid concentration reached 24.0 μmol/L, Gln-TA nanoparticles achieved the smallest particle size (247.8 nm) and the highest mechanical strength of interfacial layers, yielding the optimal short-term emulsion stability. In contrast, Gln-TA nanoparticles at a tannic acid concentration of 19.2 μmol/L exhibited the best long-term emulsion stability, which was attributed to their superior amphiphilicity and interfacial deformation resistance. This study would provide new insights into the mechanism by which Gln-TA nanoparticles enhance emulsion storage stability and establish a theoretical foundation for developing health-beneficial protein emulsifiers.