Investigation of some physical, mechanical and antimicrobial properties of bilayer pectin-carnauba wax films incorporating nanoparticles of TiO2

In this study, emulsion films based on pectin were prepared by the casting method, and the effect of titanium dioxide (TiO2) nanoparticles and carnauba wax on the mechanical and the antimicrobial properties of films were studied. The results showed that water vapor permeability was decreased by increasing of nanoparticles. Mechanical tests showed that the tensile strength (TS) of films was lower than control film duo to adding wax carnauba. But TiO2 increased the TS of films. The highest TS was observed in the films incorporating 1% TiO2. Carnauba wax increased the elasticity of films, but TiO2 reduced this parameter. Results showed that both TiO2 and carnauba wax decreased the transparency of films. In the case of the yellow index, carnauba wax increased and TiO2 decreased the “b” value. Antimicrobial test results showed that the inhibitory effect of films against Escherichia coli was increased by the TiO2 and 3% TiO2 had the highest inhibitory effect. Also, the films were studied in terms of morphology and distribution of nanoparticles using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that by increasing the nanoparticle concentration, agglomeration of nanoparticles was increased.