- - نويسنده Assistant Professor of the Department of Nanotechnology, Ahar Branch, Islamic Azad University, Ahar, Iran. Ebrahimiasl S. , - - نويسنده Assistant Professor of the Department of Chemistry Engineering, Ahar Branch, Islamic Azad University, Ahar, Iran. Younesi S. A.
ABSTRACT: The use of new compounds to increase the shelf life of more perishable foods based on nanoparticles and biodegradable polymers have been developed in packaging. Chitosan (Cts) is a natural biopolymer with excellent biodegradability and nontoxicity and antibacterial effect. In this research antibacterial copper nanoparticles (CuNPs) were incorporated in the biodegradable chitosan matrix for applications as packaging materials. The properties of Cu/Cts bionanocomposites (BNCs) were studied as a function of the CuNPs concentration. Surface morphology and elemental composition of the film was investigated by scanning electron microscopy attached to EDXRF. Mechanical analysis and water vapor barrier properties of CuNPs/Cts composites were analyzed. It was observed that mechanical and water vapor barrier properties of the films were improved by the concentration of CuNPs. The antibacterial activity of CuNPs/Cts thin films were evaluated based on the diameter of the inhibition zone in a disk diffusion test against gram positive bacteria i.e., Staphylococcus aureus and Bacillus cereus and gram negative bacteria i.e., S.epidermidis and Streptococcus A. that are responsible in food deterioration, using Mueller Hinton agar at different concentration of CuNPs. The results revealed a greater bactericidal effectiveness for nanocomposite films containing 0.15mol/L of CuSO4 solution. Packages prepared from Cts/Cu nanocomposite films were used for meat packaging. The films were filled with meat and then stored at 4 ºC. Microbial stability of the meat was evaluated after 3, 7, 10 and 15 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material.Keywords: Active Packaging, Antibacteria