Fabrication and Characterization of Guar Gum–Chitosan–Polyvinyl Alcohol–Tannic Acid–Silver‐Nanocomposite Films for Extending Fruit Shelf Life

Abstract

This research presents a sustainable film prepared by the solvent casting method, integrating tannic acid (Tn) into a composite matrix of guar gum, chitosan, polyvinyl alcohol, and silver nanoparticles (GG–CH–PVA–Tn–AgNP) for the preservation of fresh bananas, strawberries, and blueberries. With silver nanoparticles, the GG–CH–PVA–Tn–AgNP film exhibits favorable physicochemical properties, including low water solubility, moisture retention, swelling capacity, high mechanical strength up to 69.7 MPa, and low water vapor permeability. Even after 240 h of immersion, the crosslinked films remained insoluble in water. The developed film was analyzed by using FTIR, UV–vis, and XRD which confirmed strong intermolecular interactions, optimal light absorption, and improved crystallinity, consequently enhancing the material's stability and structural coherence. FESEM‐EDX, DSC, and TGA were used to examine surface morphology, elemental composition, and thermal behavior, revealing stability at temperatures up to 530°C–550°C. Soil degradation tests indicated that the film degraded by 99% within 48 days. Packaging experiments demonstrated that bananas retained freshness for up to 7 days at room temperature, and berries retained freshness for up to 30 days at 4°C under refrigerated conditions with the (GG–CH–PVA–Tn–AgNP) film. These outcomes highlight the GG–CH–PVA–Tn–AgNP film as a viable, eco‐friendly packaging alternative, granting both preservation benefits and quality assessment capabilities.