Nanocomposite film production and investigation of its possible usage on some foods packaging

In this study, Ag+TiO2 (TiO2 as the career core coated with 5% of nano-silver particles) or zinc oxide (ZnO) nanoparticles added with different ratio to low density polyethylene or polypropylene polymers respectively, to produce nanocomposite films. Effects of nanoparticles were investigated on structural and physical properties of the films. The effects of nanocomposite films on quality was analyzed on banana, lemon juice and milk samples. Therefore, the films formed as a film from polymers by extrusion method, were cut to the appropriate size for food samples and were made into bags by heat sealing. Adding nanoparticles in nanocomposite films were caused a decrease in tensile strength and percent elongation values. ZnO nanoparticles were decreased the tensile strength of nanocomposite films more than the Ag+TiO2. The addition of nanoparticles were reduced the oxygen and water vapor permeability rate of films. The migration tests of the most films in isooctane, ethyl alcohol and acetic acid were showed that the total migration limit of 10 mg/dm2 was not exceeded. However, the migration tests of LDPE based films containing 3% and 5% ZnO nanoparticles in 3% acetic acid which is representing acidic foods, were determined 15.93 and 23.29 mg/dm2, respectively. Adding of 5% Ag+TiO2 or ZnO nanoparticles in films were showed antibacterial effect against to E. coli. LDPE-based packages were showed better results to delaying the ripening of banana samples in the long term preservation than the PP-based packages. Also, adding of nanoparticles were given important properties to the packaging film as reducing the release of ethylene and keeping a low sugar content in banana samples. LDPE-based films containing 5% Ag+TiO2 were showed better results to conserve some quality of lemon juice and milk samples than the control packages.