Effect of preparation method on the structure and properties of kaempferol‐loaded zein–gum arabic nanoparticles

BACKGROUND: Kaempferol (KAE), a bioactive flavonoid, has limited solubility and stability in water. Zein-gum arabic (GA) nanoparticles (NPs) are promising carriers for KAE, but the influence of preparation methods on their structure and properties remains unclear. This study investigated the effect of preparation method on the structure and properties of KAE-loaded zein-GA NPs. RESULTS: The results showed that the NPs prepared by the antisolvent co-precipitation method (GA-zein-KAE) had a smaller particle size, a lower protein dispersibility index, a higher absolute zeta potential value, and greater encapsulation efficiency and loading capacity than NPs prepared by antisolvent precipitation (GA-zein/KAE). The superior performance of GA-zein-KAE likely resulted from the simultaneous solvent displacement of zein, GA, and KAE during co-precipitation, which promoted ternary synergistic co-assembly, homogeneous component distribution, and a stabilized composite matrix. Scanning electron microscopy revealed a smoother and more uniform surface for GA-zein-KAE, and X-ray diffraction demonstrated that KAE was encapsulated in an amorphous state within the NPs. Fluorescence spectroscopy and Fourier transform infrared spectroscopy confirmed hydrogen bonding, hydrophobic interactions, and electrostatic attractions among KAE, zein, and GA. The GA-zein-KAE also demonstrated superior re-dispersibility and stability across varying pH, ionic strength, thermal treatment, and storage conditions as well as higher antioxidant activity and faster KAE release in simulated intestinal fluid compared with GA-zein/KAE. CONCLUSION: The preparation method had a significant effect on the structure and properties of KAE-loaded zein-GA NPs, in which antisolvent co-precipitation promoted the ternary co-assembly of zein, GA, and KAE, yielding NPs with improved performance. © 2025 Society of Chemical Industry.