Chiang Mai Journal of Science

A novel biopolymer film has been developed based on natural renewable materials such as sodium alginate (SA) and carboxymethyl cellulose (CMC), which can be used as an alternative food packaging medium. The various proportions of the film-forming solution were prepared by the solvent casting method in an aqueous medium using a magnetic stirrer. Thickness uniformity, moisture content, surface morphology, moisture barrier property, optical property, and mechanical property of the prepared samples were investigated. Significant changes were observed for moisture content, UV barrier property, ductility, and water vapour permeability values concerning changes in SA/CMC concentrations. The increase in CMC concentration increased the moisture content of the film, while SA concentration leads to a decrease in the permeability to water vapor. Both SA and CMC films have strong mechanical strength, but for films with greater CMC concentration, elongation values are found to be higher. The prepared films, which contain varying concentrations of SA/CMC, have a high mechanical and barrier strength that allows them to control and retain moisture within the package, making them ideal for preserving the freshness of post-harvest fruits and vegetables.