Preparation of antimicrobial agar/banana powder blend films reinforced with silver nanoparticles.

Binary blend films of agar and banana powder (A/B) and A/B composite films reinforced with silver nanoparticles (A/B/AgNPs) were prepared using a solution casting method and their properties were characterized. The SEM micrographs and FT-IR results confirmed the formation of physical interactions between polymer matrices and nanofillers. Apparent surface color and transmittance of the composite film were greatly influenced not only by the mixing of banana powder with agar but also by the incorporation of AgNPs. The UV light absorption, water vapor barrier properties, and antioxidant activity of A/B blend films increased with the increase in the concentration of the banana powder, while the mechanical properties decreased. The A/B/AgNPs composite film exhibited distinctive antimicrobial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes with stronger antibacterial activity against Gram-negative bacteria than Gram-positive bacteria. The binary blend of A/B films are expected to be used for the edible film or coating of foods and their nanocomposite films with antimicrobial activity have a potential to be used as food packaging material for maintaining the safety and extending the shelf life of packaged food. [ABSTRACT FROM AUTHOR]