Preparation of chitosan/shellac nanoparticles-essential oil Pickering emulsion active film and its application in bread preservation

To effectively control mold and spoilage of bread and extend its shelf life, this study developed an active packaging material that possesses both antifungal activity and excellent mechanical properties. Herein, shellac nanoparticles (SNPs) were used as Pickering stabilizers to prepare SNPs-synergistic combination of cinnamaldehyde and citral (SCC) Pickering emulsion (SNPs-SCC). The SNPs-SCC was incorporating into chitosan (CS) to fabricate CS/SNPs-SCC film. Compared to the pure CS film, the tensile strength of the CS/SNPs-SCC film was enhanced by 58.89 %, while the moisture content, water solubility, water vapor permeability, and oxygen permeability were reduced by 52.89 %, 26.88 %, 45.28 %, and 40.51 %, respectively. Additionally, the CS/SNPsSCC film demonstrated almost complete absorption of ultraviolet light in the wavelength range of 100-400 nm and was capable of complete biodegradation within 50 days. In vitro, antifungal tests revealed that the CS/SNPsSCC film exhibited satisfactory antifungal activity against Aspergillus niger and Penicillium citrinum. Notably, the CS/SNPs-SCC film significantly extended the shelf life of bread by 5 days compared to the oriented polypropylene (OPP) film. Therefore, the CS/SNPs-SCC film holds potential for application as a novel active packaging material for bread preservation.