Development and characterization of biodegradable chitosan-alginate/ZnO coating for banana preservation

In this study, we successfully synthesized ZnO nanomaterials by co-precipitation method and used ZnO integrated into chitosan-sodium alginate (CS-Alg) biodegradable film for post-harvest preservation of bananas. ZnO nanomaterials have a size of about 20 nm, a surface area of 36.74 m 2 /g and a pore volume of 0.133 cm 3 /g. Sodium alginate (Alg) and ZnO fillers incorporated into the chitosan structure increased the tensile strength (38.75 MPa) and elongation at break (12.86%) of the chitosan film. The CS-Alg/ZnO films was able to extend the post-harvest shelf life of bananas up to 14 days compared to 9 days for bananas without coating under the same experimental conditions. Bananas preserved by the CS-Alg/ZnO films improved the color of the peel, prevented water loss, increased the firmness of the fruit flesh and maintained nutritional quality during storage.