Polyphenolic composite nanocoating with trans ‐cinnamaldehyde nanoemulsion stabilized by lactoferrin

Abstract A chemical strategy depositing functional nanoemulsions onto Fe(III)‐tannic acid (TA) priming layers enables the fabrication of polyphenolic composite nanocoatings. Optimization of the composition yields stable nanoemulsions (~200 nm) utilizing a 1:1 trans ‐cinnamaldehyde/olive oil core and a lactoferrin shell. These nanoemulsions demonstrate superior colloidal stability, specifically maintaining dispersion stability for 7 days at room temperature, resisting heat up to 60°C, and withstanding centrifugal shear forces. Notably, a 3‐day incubation triggers interfacial conjugation between trans‐cinnamaldehyde and lactoferrin. On Fe(III)‐TA‐primed surfaces, these nanoemulsions promote the uniform growth of multinary composite nanofilms. This methodology offers a versatile, biocompatible approach to developing tailored composite nanocoatings, establishing a robust platform for engineering functional interfaces in food and biomedical applications.