Semi-transparent regenerated cellulose/ZnONP nanocomposite film as a potential antimicrobial food packaging material

A facile and straightforward route was proposed for preparing semi-transparent antimicrobial nanocomposite films using regenerated cellulose (RC) and zinc oxide nanoparticles (ZnONP) with acceptable transparency for potential food packaging applications. The RC/ZnONP nanocomposite films were characterized by their mechanical strength, UV-vis barrier properties, water vapor permeability (WVP), and antimicrobial activities against six foodborne pathogenic bacteria. The UV and oxygen barrier properties, thermal stability, and crystallinity of the RC/ZnONP nanocomposite films were significantly (p < 0.05) improved by adding 7 wt% of ZnONP to RC films. However, the mechanical strength and WVP of the RC/ZnONP nanocomposite films were not significantly (p > 0.05) altered by the addition of ZnONP. As shown in SEM and AFM images, the addition of ZnONP altered the surface morphology of the RC/ZnONP nanocomposite films. The results of antimicrobial tests indicated that adding 3 wt% of ZnONP could effectively inhibit the growth of pathogenic foodborne grampositive (B. cereus, S. aureus, and L. monocytogenes) and gram-negative (E. coli, S. typhimurium, and V. parahaemolyticus) bacteria. UV transmittance and oxygen permeability of films reduced by 32 and 37%, respectively, at a ZnONP concentration of 3 wt%. Owing to the significant antibacterial activity of prepared films against the bacteria mentioned before, they could be applied for packaging meat products.

Automated summary

The addition of ZnONP significantly improved the barrier properties and antimicrobial activity of the nanocomposite films, while showing no significant impact on the mechanical strength and water vapor permeability of the films. UV transmittance and oxygen permeability of the films were reduced at a ZnONP concentration of 3 wt%.