Antimicrobial packaging of ZnO–Nps infused into CMC–PVA nanocomposite films effectively enhances the physicochemical properties

Abstract

The objective of this work was to investigate the effect of ZnO nanoparticles (ZnO–Nps) on the physicochemical properties of carboxymethyl cellulose–polyvinyl alcohol (CMC–PVA) films and the release kinetics of the nanoparticles into food simulants were studied. The tensile strength and elongation at break of the CMC–PVA/ZnO nanocomposite were improved from 15.80 MPa to 47.50 MPa and 179.0% to 275.30% by adding 1.5 wt% of ZnO. Moreover, the solubility, swelling water, and water vapor transmission rate (WVTR) values were reduced and improved the opacity, UV barrier ability and moisture retention capability (MRC) with the increasing of ZnO concentration. Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) was used to demonstrate the success of ZnO–Nps infused into the CMC–PVA. The films exhibited good antibacterial activity against both E. coli and S. aureus in inhibition zones of 2.15 ± 0.42 mm and 3.25 ± 0.47 mm, respectively. The release kinetics for Zn in simulant of ethanol and acetic acid show the Korsmeyer-Peppas model corresponding to a non-Fickian release were associated with the film's swelling, diffusion, and the release kinetics are dependent on the concentration of Zn in the films. Therefore, nanocomposite-based CMC–PVA biopolymers containing ZnO–Nps have the potential to be used as environmentally friendly food packaging.

Keywords

• Antimicrobial packaging
• Biopolymers
• Nanocomposite films
• Polyvinyl alcohol
• ZnO–Nps