Characterisation of ternary blend film of alginate/carboxymethyl cellulose/starch for packaging applications

Sodium alginate (SA), carboxymethyl cellulose (CMC) and potato starch (PS) based functional packaging films were prepared by solvent casting method. The sample films were prepared with varying concentrations of SA/CMC and PS. The chemical, morphological, and thermal characterisation of the prepared films was investigated using FTIR, XRD, SEM and TGA analysis. The physical, optical, moisture, mechanical, and barrier properties were evaluated as a function of the SA/CMC and PS concentrations, and the results were analysed. The increased concentration of PS improved the barrier properties against UV, oxygen, and water vapour, along with decreasing the moisture content and elongation of the sample film. The prepared films with PS had uniform thickness, enhanced thermal stability and high tensile strength. The incorporation of 50% PS reduced the UV transmittance from 25.80% to 1.89%, and the tensile strength of the sample film was increased from 20.44 MPa to 31.95 MPa, whereas the elongation reduced from 34.86% to 13.78% and the moisture content from 29.15% to 16.21%. The shelf life analysis revealed that the produced film has the efficiency to enhance the post-harvest shelf life of black and green grapes by up to 16 days, confirming the potential use of SA/CMC/PS films in packaging applications.