Characterization and application of the nanocompiste packaging films containing clay and TiO2 on preservation of tomato fruit under cold storage

Tomato (Lycopersicon esculentum), a valuable economic crop worldwide, often goes to waste due to improper packaging and handling. In the present study, three types of low-density polyethylene nanocomposite films containing 3% clay (Closite 20A), 3% TiO.sub.2 nanoparticles, and their combination were synthesized using melt blending method, and evaluated on the quality parameters of tomato fruit during 42 days of storage at 4 [degrees]C. Transmission electron microscopy confirmed the degree of dispersion and exfoliation of the nanoparticles. The TiO.sub.2/clay-nanocomposite films exhibited notable enhancements in Young's modulus and tensile strength compared to conventional films. The addition of clay and TiO.sub.2 nanoparticles resulted in reduced permeability to CO.sub.2, O.sub.2, and water vapor. Fruits packed with clay/TiO.sub.2 nanocomposite films showed decreased ethylene production, mitigated weight loss, and maintained pH, titratable acidity, total soluble solids, and firmness. Furthermore, clay/TiO.sub.2 nanocomposite films enhanced membrane stability, decreased membrane lipid peroxidation, and enhanced catalase and ascorbate peroxidase enzyme activity in fruits. The relatively good exfoliation of clay nanoparticles and the proper dispersion of TiO.sub.2 nanoparticles, which were confirmed by TEM, led to an increase in mechanical and physical properties in the Clay/TiO.sub.2 nanocomposite. This film displayed more potential in maintaining the quality properties of tomato fruit during cold storage. Therefore, this film can be considered a practical solution for minimizing pathogen risks and contamination, and enhancing the overall quality of tomato fruit.