Fabrication of cinnamaldehyde–shellac nanoparticle‐filled chitosan packaging material and application in chilled beef preservation

Cinnamaldehyde (CA) is the main functional component of cinnamon essential oil, exhibits strong anti-microbial activity and safety. Shellac (SHL) nanoparticles enable the encapsulation and controlled release of CA while improving the physiochemical properties of chitosan (CS) films. To strengthen the anti-bacterial activity of SHL-CS films, CA-SHL nanoparticles were prepared by an anti-solvent precipitation method with Tween 80 as surfactant, and subsequently incorporated into CS film-forming solution. The resulting CA-SHL nanoparticle-filled CS coatings were then applied for the preservation of chilled beef. The particle size of CA-SHL nanoparticles showed a unimodal distribution, decreasing with higher SHL content or lower CA concentration. Stable CA-SHL nanoparticles had relatively low zeta-potential values, indicating the stabilization effect of Tween 80. Incorporation of CA-SHL nanoparticles into CS films improved UV barrier properties, reduced water vapor permeability, improved pH corrosion resistance, and strengthened anti-bacterial activity. The CA-SHL nanoparticle-filled CS coatings extended the shelf life of chilled beef from 4 to 8 days. The enhanced properties of CA-SHL nanoparticle-filled CS composite films highlight their strong potential for food packaging and preservation.