Development of polyvinyl alcohol/carboxymethylcellulose-based bio-packaging film with citric acid crosslinking and clove essential oil encapsulated chitosan nanoparticle pickering emulsion.

This study developed polyvinyl alcohol (PVA)/carboxymethylcellulose (CMC)-based films, using citric acid (CA) as a non-toxic crosslinking agent, to enhance the shelf life of water-soluble packaging films. Clove essential oil (CEO)-loaded chitosan nanoparticles (CSNPs) were prepared via Pickering emulsion and incorporated into PVA/CMC/CA composite films. The encapsulation of CEO was confirmed by FTIR and optical microscopy. Thermal properties were analyzed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), revealing improved thermal stability and a decrease in glass transition temperature (Tg) upon crosslinking. The formation of ester bonds was confirmed by ATR-FTIR and CNMR. Water contact angle (WCA) measurements showed a decrease in hydrophilicity, enhancing the barrier properties of the films. SEM images demonstrated good dispersion of CSNP/CEO within the matrix, improving mechanical and barrier properties. The films exhibited a 30 % reduction in water vapor permeability and water solubility. Controlled release studies indicated that the composite films sustained CEO release, extending the shelf life of cherry tomatoes. Thus, these PVA/CMC/CA-CSNP/CEO composite films offer strong potential for food preservation applications.