Eco-friendly cellulose acetate green synthesized silver nano-composite as antibacterial packaging system for food safety

The current study focused on preparation of environmentally safe nano-composite films from a mixture of cellulose acetate (CA) and nanosilver for using it as an antibacterial food packaging system against some foodborne pathogenic bacteria. Green synthesized silver nanoparticles (AgNPs) were prepared using different poly-phenolic; gallic and pyrogallic acid, quercetin and rutin and then characterized. UV-vis spectral was detected peaks in the area of AgNPs formation and High Resolution Transmission electron microscopy (HRTEM) revealed that formation of nearly spherical AgNPs with an average size of 5 to 18 nm. All AgNPs had activity against the examined pathogenic bacteria reached to 10 folds more than the normal form of poly-phenolics. Also, minimal inhibitory concentration (MIC) values were ranged between 16.7 and 46.7 mu g ml(-1). The films of CA-nanocomposite were prepared by phase inversion technique. The obtained films were characterized by FTIR, SEM, EDX techniques and their swelling properties were determined. Also, antibacterial activity of the film was assessed. CA-nanocomposite had high antibacterial activity against St. aureus, B. cereus, S. typhi, E. coli, K. pneumoniae and low activity against the two strains of Pseudomonase spp. All tested immersed films showed no toxic effect against larvae even used quercetin in the preparation (< 18% mortality). The released amount of Ag nanoparticles from different CA-nano-composite films was also less than the allowable limit. The current work conclude that the poly-phenolic CA -Ag nano-composite films had strong antibacterial activity with nontoxic effect, which increases the possibility of applying it as an active food packaging system.