Antimicrobial edible films inhibit pathogens in meat

Antimicrobial agents incorporated into edible films applied to foods to seal in flavour, freshness and colour can improve the microbiological safety of meats, according to new research.
Using films made of pullulan - an edible, mostly tasteless, transparent polymer produced by the fungus reobasidium pulluns - researchers evaluated the effectiveness of films containing essential oils derived from rosemary, oregano and nanoparticles against foodborne pathogens associated with meat and poultry.
The results demonstrate that the bacterial pathogens were inhibited significantly by the use of the antimicrobial films, said Catherine Cutter, professor of food science at The Pennsylvania State University.
She hopes that the research will lead to the application of edible, antimicrobial films to meat and poultry, either before packaging or, more likely, as part of the packaging process.

In the study, researchers determined survivability of bacterial pathogens after treatment with 2 per cent oregano essential oil, 2 per cent rosemary essential oil, zinc oxide nanoparticles or silver nanoparticles.
The compounds then were incorporated into edible films made from pullulan, and the researchers determined the antimicrobial activity of these films against bacterial pathogens inoculated onto petri dishes.

Finally, the researchers experimentally inoculated fresh and ready-to-eat meat and poultry products with bacterial pathogens, treated them with the pullulan films containing the essential oils and nanoparticles, vacuum packaged, and then evaluated for bacterial growth following refrigerated storage for up to three weeks.

"The results from this study demonstrated that edible films made from pullulan and incorporated with essential oils or nanoparticles have the potential to improve the safety of refrigerated, fresh or further-processed meat and poultry products," said Cutter.
"The research shows that we can apply these food-grade films and have them do double duty - releasing antimicrobials and imparting characteristics to protect and improve food we eat," said Cutter.
The study was published in the Journal of Food Science.