An active biodegradable layer-by-layer film based on chitosan-alginate-TiO₂ for the enhanced shelf life of tomatoes

This work aims at developing biodegradable active chitosan-alginate layer-by-layer bio-nanocomposite film with TiO₂NPs using the solvent casting method followed by CaCl₂ crosslinking for food packaging applications. The developed films enhanced the tensile strength and elongation at break by 14.76 and 2 folds (p < 0.05) respectively. The UV barrier properties of CH-SA-0.3%TiO₂ film increased by 88.6%, while the film transparency decreased by 87.23%. All films showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene. The film with 0.1%TiO₂ showed the complete killing of gram-positive bacteria. The CH-SA-0.1%TiO₂ film was completely biodegraded during the 3 months. The CH-SA-0.3%TiO₂ film showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability properties the prepared films could be considered a potential candidate for fresh produce packaging.