Jackfruit seed starch/tamarind kernel xyloglucan/zinc oxide nanoparticles-based composite films: Preparation, characterization, and application on tomato (Solanum lycopersicum) fruits

Agricultural by-products such as jackfruit seed starch (JSS) and tamarind kernel xyloglucan (XG) were extracted, characterized, and utilized to develop biodegradable food packaging materials. JSS/XG nanocomposite films were prepared by reinforcing with zinc oxide nanoparticles (ZNPs). The blending of JSS with XG reduces the hydrophilicity of the composite films and improves the material strength. The rheological tests indicate that ZNPs incorporation improved the apparent viscosity and dynamic moduli of the film-forming solutions. The ZNPs-loaded nanocomposites showed enhanced UV and water vapor barrier properties. The addition of ZNPs effectively transferred the stress to the interface and increased the mechanical properties. The stress relaxation study shows that ZNPs-incorporated films exhibited better resistance to stress relaxation and polymer chain breakage. The FTIR spectra revealed the formation of non-covalent interactions such as hydrogen bonding between polymers and nanoparticles. The XRD results demonstrate that ZNPs incorporation increased the crystallinity of the nanocomposites. The SEM micrographs showed an increase in surface roughness and aggregates with the increase in ZNPs concentration. The increased glass transition and melting temperatures in the ZNPs-loaded films indicate enhanced thermal stability. The nanocomposite films demonstrated potent antimicrobial activity against Staphylococcus aureus and Escherichia coli. The prepared formulations were used to coat tomato fruits, which resulted in delayed quality loss and extended shelf-life. Therefore, the prepared JSS/XG/ZNPs nanocomposites are promising eco-friendly packaging materials that could be used to extend the shelf-life of food products.