Development of nano-ZnO coated food packaging film and its inhibitory effect on Escherichia coli in vitro and in actual tests

摘要

In this study, we investigated antibacterial activity of zinc oxide (ZnO) nanoparticles coated on polyvinyl chloride (PVC) films against Escherichia. coli both in vitro and in actual test. Results showed that the nano-ZnO coated films displayed excellent inhibition effects on the growth of E. coli and the nano-ZnO particular was contributed to the bactericidal ability. The more amounts of the ZnO particulars the film coated, the greater inhibitory effect it exhibited. The disinfection efficiency with ZnO film is relatively constant at pH values in the range of 4.5 to 8.0. In the actual test, the number of E. coli cells from cut apple stored in a ZnO-coated bag in the dark decreased from 8.72 to 6.3 log CFU/ml after 1 day, while that of an same bag irradiated with light decreased from 8.72 to 3.5 log CFU/ml after 2 days of storage. The results reveal that nano-ZnO coated film has a good promise to make antimicrobial packaging again E. coli and reduce the risks of microbial growth on fresh-cut produce.