Preparation, characterization, and antimicrobial activity of novel chitosan blended almond gum–nanosilica bionanocomposite film for food packaging applications

Almond gum and varied concentrations of nanosilica (0.2, 0.4, 0.6, 0.8, and 1.0 wt%) were introduced into the chitosan polymer matrix by solution cast method to enrich the characteristics of the bionanocomposite film. The surface topography, thermal stability, crystalline nature, and functional moieties of the synthesized bionanocomposite films were characterized by SEM, TGA, XRD, and FT-IR. The UV–Vis spectrophotometer showed a maximum absorption wavelength for the film containing the highest concentration of nanosilica. Change in properties such as increased tensile strength, elongation and reduced water solubility, and swelling properties were observed for the bionanocomposite film containing 1.0 wt% nanosilica. In addition, the films exhibited excellent inhibition effect against Escherichia coli bacteria and Candida albicans fungus, which were proven by well diffusion assay method. The carrot slices packed in the bionanocomposite film containing the highest amount of nanosilica retained their freshness for a longer period of time, suggesting the film to be an effective and excellent food packaging material.