Development of chitosan coating loaded with solvothermal-prepared cerium oxide for banana preservation

In this work, cerium oxide nanoparticles prepared through the solvothermal route (sCeO₂ NPs) are integrated into chitosan (CH) matrices to serve as an efficient coating for banana preservation. The morphological, structural, mechanical, and water-barrier properties of nanocomposite films integrated with various sCeO₂ concentrations were investigated to determine the optimal sCeO₂ NPs concentration within the film matrix. Furthermore, the sensory evaluation and physicochemical properties of the coated and uncoated bananas, including visual attributes, peel browning, CO₂ production, firmness, weight loss, ripening rate (based on total soluble solids and titratable acidity), and pH, are considered during storage. The obtained results revealed that adding 1-2% (w/w) sCeO₂ NPs significantly revitalized the nanocomposite films' fracture strength, flexibility, UV shielding, and water-barrier function. Notably, the inclusion of 1.5% (w/w) of sCeO₂ NPs in the nanocomposite coating results in a 154% increase in fracture strength and a 36% increase in flexibility. In the preservation experiment, the 1.5% (w/w) sCeO₂-loaded CH coating formulation exhibited superior performance than CH and commercial preservatives by effectively slowing down weight loss, CO₂ production, hardness, and ripening of bananas and thereby extending the banana shelf life up to 10 days. Therefore, CH-sCeO₂ nanocomposite coatings are feasible and viable alternatives for extending the expiration date of fresh bananas.