Fabrication of a zein-phloretin complex and nanoparticles: interaction mechanism and characterization

Due to its capacity to form complexes with polyphenols and to self-assemble as nanoparticles, zein could be utilized as an excellent carrier for polyphenols. The objective of this study was to examine the interaction between zein and phloretin (PHL) through multispectral analysis and molecular docking, and to prepare and characterize PHL-loaded zein nanoparticles. Spectral analysis and docking data confirmed that the binding process of the zein-PHL complex is mainly influenced by hydrogen bonding and van der Waals forces, and hydrophobic interaction was auxiliary, with static quenching as the primary fluorescence quenching mechanism. Meanwhile, zein nanoparticles loaded with PHL were successfully prepared using the anti-solvent precipitation method, which was evidenced by the morphology and size characterization. The hydrogen bond and hydrophobic interaction in the nanoparticles were further confirmed by Fourier transform infrared spectroscopy. This study elucidates the noncovalent interaction mechanism between zein and PHL, providing a theoretical foundation for the design of zein-polyphenol nanocarriers. These carriers show promising applications as emulsion stabilizers or delivery systems for lipophilic bioactives, thereby facilitating the development of functional foods with improved stability and enhanced bioavailability.