Improving the properties of chitosan films by incorporating shellac nanoparticles

Chitosan (CS) film has unique advantages, however, the poor physicochemical properties greatly limit its practical application. Interestingly, shellac nanoparticles (SNPs) could be used to enhance the properties of CS films. The particle size, ζ-potential, and dispersibility of the SNPs prepared by the anti-solvent precipitation method were detected by a laser nanometer particle size analyzer, and the results showed that the SNPs had concentration-dependent particle size, good dispersibility, and good stability. The SNPs incorporated CS films (CSNPs) were prepared by solution-casting. The chemical structures of the CSNPs films were characterized by FT-IR, and the surface and cross-section morphologies of the films were characterized by scanning electron microscopy (SEM). Furthermore, the physical properties, including thermal stability, mechanical properties, color parameters, water vapor permeability, and UV barrier characteristics, were also characterized. The results showed that SNPs could uniformly disperse in the films, and therefore significantly enhanced the thermal stability, color, mechanical properties, and UV adsorption of the films while reduced the water vapor permeability of the films. More notably, curcumin-incorporated CSNPs films had shown good effects on preventing shrimp spoilage. [Display omitted] •Shellac nanoparticles (SNPs) were obtained through the anti-solvent precipitation method.•Novel SNPs-filled chitosan films (CSNPs) were fabricated by solution-casting.•SNPs were well embedded into CSNPs films because of the electrostatic interaction.•The inclusion of SNPs could improve the structure and properties of the CSNPs films.•CSNPs films with enhanced preservation effect by encapsulating curcumin-loaded SNPs.