Biodegradable Poly(Butylene Adipate-Co-Terephthalate) and Thermoplastic Starch-Blended TiO2 Nanocomposite Blown Films as Functional Active Packaging of Fresh Fruit

Biodegradable polymers can be used for eco-friendly, functional, active packaging to preserve food quality. Incorporation of titanium dioxide (TiO2) nanoparticles into polymer packaging enhances ethylene-scavenging activity and extends the shelf-life of fresh produce. In this study, TiO2 nanoparticles were incorporated into biodegradable poly(butylene adipate-co-terephthalate) (PBAT)- and thermoplastic cassava starch (TPS)-blended films to produce nanocomposite packaging via blown-film extrusion. The effects of TiO2 on morphology, packaging properties, and applications as functional packaging for fresh produce were investigated. Increased TiO2 in the film packaging increased amorphous starch content and hydrogen bonding by interacting with the TPS phase of the polymer blend, with negligible chemical interaction with the PBAT component and identical mechanical relaxation in the PBAT phase. Surface topography indicated void space due to non-homogeneous dispersion causing increased oxygen and carbon dioxide permeability. Homogeneous dispersion of fine TiO2 nanoparticles increased mechanical strength and reduced oxygen, carbon dioxide, and water vapor permeability. Films containing TiO2 also showed efficient oxygen-scavenging activity that removed residual oxygen from the package headspace dependent on the levels and morphology of nanoparticles in the film matrices. Banana fruit packaged in films containing TiO2 recorded slower darkening color change and enhanced shelf-life with increasing TiO2 content.

Automated summary

The incorporation of TiO2 nanoparticles into biodegradable polymer packaging improves the preservation and shelf-life of fresh produce by enhancing ethylene-scavenging activity and mechanical strength. Interaction between TiO2 and TPS phase increases amorphous starch content and hydrogen bonding in the film packaging, while having a negligible chemical interaction with the PBAT component. Homogeneously dispersed fine TiO2 nanoparticles increase mechanical strength and reduce permeability to oxygen, carbon dioxide, and water vapor, leading to effective oxygen-scavenging activity in the packaging.