Preparation of chitosan-TiO2 composite film with efficient antimicrobial activities under visible light for food packaging applications

Abstract

By incorporation of TiO₂ nano-powder in chitosan, a chitosan-TiO₂ composite film was prepared with efficient antimicrobial activity against food-borne pathogenic microbes and expected to be a promising food packaging material. Scanning electron microscopy analysis showed that the TiO₂ nano-powder was successfully and uniformly dispersed into the chitosan matrix. TiO₂ addition led to enhanced hydrophilicity, to better mechanical properties, and to decreased light transmittance in visible light region of the composite film. The chitosan-TiO₂ film possessed efficient antimicrobial activity against four tested strains, i.e. Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus niger with 100% sterilization in 12h. It moreover provoked the leakage of cellular substances through damaged membrane. The prepared chitosan-TiO₂ film was tested for packaging red grapes to prevent microbial infection and extend their shelf life. Results were positive, stressing the potential of the novel bio-nano composite film for food packaging applications.

Keywords: Antimicrobial activity; Chitosan; Food packaging; Nano-TiO(2); Visible light.