Antimicrobial bio-nanocomposite films based on gelatin, tragacanth, and zinc oxide nanoparticles - Microstructural, mechanical, thermo-physical, and barrier properties

Gelatin and tragacanth were employed to fabricate antimicrobial nanocomposites with 1, 3, and 5% zinc oxide nanoparticles (ZnO-NPs). FT-IR and XRD proved new chemical interactions among GEL/TGC/ZnO-NPs and higher crystallinity of nanocomposites, respectively. DSC showed a significant increase in melting point temperature (Tm) from - 90 to - 93?101 ?C after adding 1?5% ZnO-NPs. Ultimate tensile strength (UTS) was remarkably increased to 31.21, 34.57, and 35.06 MPa, as well as Young?s Modulus to 287.44, 335.47, and 367.04 MPa after incorporating 1, 3, and 5% ZnO-NPs. The ZnO-NPs dose-dependently reduced the water vapor permeability (WVP) of the films. FE-SEM analysis from surface and cross-section illustrated the compact and homogenous structure of the nanocomposites even up to 5% ZnO-NPs. The ZnO-NPs-containing nanocomposites had a good antimicrobial activity (-10?20 mm) against both Staphylococcus aureus and Escherichia coli. Generally, the results indicated that the prepared nanocomposite films are promising antimicrobial bio-materials for food packaging.

Automated summary

The addition of 1%, 3%, and 5% zinc oxide nanoparticles to gelatin and tragacanth resulted in antimicrobial nanocomposites with increased melting point temperature, ultimate tensile strength, and Young's Modulus. These nanocomposites exhibited reduced water vapor permeability and good antimicrobial activity against Staphylococcus aureus and Escherichia coli, showing promise as bio-materials for food packaging.