Properties of nisin incorporated ZrO2/poly (vinyl alcohol)-wheat gluten antimicrobial barrier films

The properties of manufactured nisin-ZrO2/poly (vinyl alcohol)-wheat gluten (ZPWG) films were characterized. The formation of hydrogen bonds among the PVA, WG, and ZrO2 units were detected and caused a decrease in the film crystallinity. Also, the degradation rate was increased with WG content. As expected, the addition of WG and ZrO2 influenced the light transmission, tensile properties, gas permeability and water vapor permeability of the films. Nisin-loaded films presented a low initial burst release of the antimicrobial agent, followed by a gradual release. The initial diffusion of nisin (Mt/M∞<2/3) from the ZPWG film was formulated by the Fickian diffusion equation, showing a linear relationship (R2 > 0.998) between Mt/M∞ and t1/2, and the diffusion coefficient D increased with increasing WG content. Antimicrobial activity testing of nisin-ZPWG films with 40 wt% WG showed excellent inhibitory activity against Staphylococcus aureus, indicating its potential as a new active food packaging material.