Effect of Silicon Carbide Nanoparticles on the Mechanical, Barrier, Antibacterial and Biodegradable Properties of Pullulan/Lignin Bio Nanocomposite Blends for Food Packaging Applications

Abstract

In this study, pullulan, lignin and silicon carbide-based bio nanocomposite films were prepared and characterized for food packaging applications. Pullulan/lignin bio nanocomposite films were prepared by solvent casting method with various wt% (0.1, 0.2, 0.3, 0.4 and 0.5) of silicon carbide. The structure and morphology of the prepared bio nanocomposite films were characterized by FT-IR and SEM. SEM analysis revealed that the silicon carbide was properly distributed in the pullulan/lignin matrix. The addition of silicon carbide to pullulan and lignin increased the density and decreased the porosity of the films. The moisture content of the films was also reduced by the addition of various concentrations of silicon carbide. The surface colour difference and opacity of the bio nanocomposite films increased from 48.06 to 71.50 and from 4.3% to 71.9%, respectively. The surface hydrophobicity of the bio nanocomposite films increased with the addition of silicon carbide and a maximum value of 84.2° was achieved for 0.5 wt%. The tensile strength of the films also increased from 6.12 MPa to 14.24 MPa. The addition of silicon carbide also reduced the oxygen transmission rate and water vapour transmission rate of the pullulan-based bio nanocomposite films. The films exhibited good antibacterial activity against Staphylococcus aureus and Escherichia coli, which was mainly attributed to the synergetic antibacterial action of lignin. In addition, the bio nanocomposite films have excellent biodegradability. This proves to be a novel research concept for environmental friendly greener packaging materials for active food packaging applications.