Research from the US has found a composite film could help reduce the amount of foodborne illness outbreaks. The film combines an antimicrobial layer to a clear, polyethylene plastic, commonly used to vacuum-package meat and fish.
Penn State’s College of Agricultural Sciences has applied for a provisional patent on the film, as foodborne illnesses account for 76 million cases in the US alone each year, with 300,000 hospitalisations and 5,000 deaths, according to the US Centres for Disease Control and Prevention.
The film’s antimicrobial lining is made of a pullulan-based biopolymer created from starch syrup during fermentation, and is already approved for food use.
Pullulan is water-soluble and “is essentially a chain of sugar, glycerin and cellulose molecules linked together”. It is infused with lauric arginate – which is also approved for use in foods, and made from naturally occurring substances – to help kill pathogens such as salmonella, listeria and pathogenic E. Coli.
“Lauric arginate is a safe, completely nontoxic ingredient,” said assistant director of food safety and quality programs for Penn State Extension Catherine Cutter.
“It is hydrolysed in the human body by chemical and metabolic pathways, which quickly break it into its naturally occurring components — lauric acid and L-arginine.”
The pullulan film can slow the release of the antimicrobial at a “predictable rate” to provide ongoing bacteria-killing activity, and has been proven as highly effective in killing and limiting the growth of pathogens causing foodborne illnesses, Cutter said.
She credits visiting associate professor of food safety and technology at Beni-Suef University in Egypt, Abdelrahim Hassan, for discovering how to attach the pullulan to polyethylene.
“Hassan modified the formulation of pullulan and changed the hydrophobicity of the plastic. These steps were important because polyethylene repels everything — nothing sticks to it. So, the challenge was, how could we get pullulan to adhere to it,” said Cutter.
The study inoculated pathogens on raw beef, raw chicken breast and ready-to-eat turkey breast and vacuum-packaged it with the film, before sealing and placing into refrigerated storage for 28 days.
It found the film “significantly reduced foodborne pathogens on the experimentally inoculated surfaces of the raw and ready-to-eat muscle foods”.
The findings “will be of interest to the packaging and muscle food industries,” Cutter adds, with future research aiming to evaluate how the composite antimicrobial film can affect shelf life of food products, as well as investigating consumer perceptions of the film.
Commenting on the development, Melbourne-based O F Packaging research and innovation engineer Paul Ehrlich told PKN it was exciting to see the technology being applied to flexible packaging.
"Although in very early stages being developed at a university, I can fore see it will take some time for this technology to scale up to be mass produced and ready for commercial applications," said Ehrlich.
"In addition to this, the fact this is using a polyethylene base material means it can be made to be ‘recycle friendly’ as we move to more sustainable packaging solutions."
"We will be watching this space closely with the hope of conducting trials once a commercially viable solution is available."
