Properties and characterization of bionanocomposite films prepared with various biopolymers and ZnO nanoparticles

• Active nanocomposite films were prepared by addition of ZnO NPs into biopolymers.
• UV, surface hydrophobicity and water vapor barrier properties were increased.
• The mechanical properties were greatly affected by presence of ZnO.
• The nanocomposite films were found to have rough surface structure with ZnO.
• The nanocomposites films exhibited better antimicrobial effect against pathogens.

This study was aimed to develop biopolymer based antimicrobial films for active food packaging and to reduce environmental pollution caused by accumulation of synthetic packaging. The ZnO NPs were incorporated as antimicrobials into different biopolymers such as agar, carrageenan and CMC. Solvent casting method was performed to prepare active nanocomposite films. Methods such as FE-SEM, FT-IR and XRD were used to characterize resulting films. Physical, mechanical, thermal and antimicrobial properties were also examined. Remarkable surface morphological differences were observed between control and nanocomposite films. The crystallinity of ZnO was confirmed by XRD analysis. The addition of ZnO NPs increased color, UV barrier, moisture content, hydrophobicity, elongation and thermal stability of the films, while decreased WVP, tensile strength and elastic modulus. ZnO NPs impregnated films inhibited growth of L. monocytogenes and E. coli. So these newly prepared nanocomposite films can be used as active packaging film to extend shelf-life of food.