Composite antimicrobial films activated by essential oil Pickering emulsions: Preparation, characterization and application in pork preservation

In this work, we provided a facile way to prepare composite antimicrobial films based on polyvinyl alcohol (PVA) incorporated with Zanthoxylum schinifolium essential oil/cinnamaldehyde (ZSEO/CA) Pickering emulsion, and applied them for the preservation of chilled fresh pork. The ZSEO/CA Pickering emulsions stabilized by bacterial cellulose nanofibrils/whey protein isolate (BCNFs/WPI) complexes exhibited uniform droplet size distribution (around 150 nm) and maintained the better stability with an oil phase ratio of 10 wt%, which was selected for subsequent composite film preparation. Compared to pure PVA film, the addition of ZSEO/CA Pickering emulsion in composite films reduced their transmittance, but provided a significant barrier against ultraviolet light. Moreover, the incorporation of emulsion enhanced the hydrophobicity, thermal stability, water vapor permeability (WVP) and antibacterial activity of the composite films. Among them, the composite antimicrobial film with an emulsion proportion of 30 wt% (PVA-PE(30)) showed the optimal performance characteristics, and effectively prolonged the chilled fresh pork storage period. Overall, the incorporation of ZSEO/CA Pickering emulsion into PVA-based films provided a promising strategy to construct composite antimicrobial films for food packaging and preservation.