Cold-plasma-induced modification of chitosan-zein nanoparticles confer Pickering emulsion stability

To improve the stability and emulsifying properties of chitosan-zein composite nanoparticles, dielectric barrier discharge cold plasma (DBD-CP) was employed in this study, and its potential as a stabilizer was evaluated. The results showed that the DBD-CP treatment reduced the particle size, increased the zeta potential, and enhanced the surface wettability. Scanning electron microscopy imaging revealed dense interfacial adsorption layers of composite nanoparticles at the oil-water interface. Additionally, X-ray diffraction, Fourier transform infrared spectroscopy, intrinsic fluorescence spectroscopy, thermogravimetric analysis, and nuclear magnetic resonance analyses indicated chemical group displacements and new crystal phase formations, suggesting structural reorganization. In the application of Pickering emulsions (PEs) for stabilization, emulsions encapsulated with lemon essential oil demonstrated increased zeta potential and improved emulsion stability, accompanied by sustained oil release. This indicated that DBD-CP technology transformed composite nanoparticles into efficient PEs stabilizers, thereby enhancing emulsion stability and retarding essential-oil release. Furthermore, utilizing DBD-CP technology for treating chitosan and zein separately before combining them to form a stabilizer offered significant advantages. This pre-combination strategy not only augmented the encapsulation efficiency of essential oils from 79.71 ± 1.41 % to 91.57 ± 0.71 % but also improved emulsion stability from 30.80 ± 1.55 % to 80.50 ± 1.24 %, outperforming other treatment groups. These results further confirmed the effectiveness of the proposed method as an optimal DBD-CP treatment strategy for bioactive compound delivery systems.