A biodegradable, edible film made with plant starch and antimicrobial compounds may control the growth of foodborne pathogens on seafood, according to researchers from Penn State and other schools.
A big challenge the food industry faces is reducing the reliance on plastic packaging, says Catherine Cutter, a professor of food science at Penn State. The new research, which will be published in the February issue of the International Journal of Food Microbiology, could pave the way for alternative forms of seafood packaging.
"We have the ability to develop a film with antimicrobial activity that can kill foodborne pathogens on food surfaces," Cutter says. "Given the recent outbreaks that we have seen with a number of food products, coming up with something that can be used by the industry to kill microorganisms on the surfaces of food is a noble area of research to investigate."
Researchers used a blend of thermoplastic starch, a biodegradable polymer made from cassava — tapioca powder, and a gelatin coating containing antimicrobials known as Nisin Z and lauric arginate. The team then created a "culture cocktail" of the bacteria and inoculated slices of tiger prawn and big-eye snapper.
The experimentally-inoculated seafood samples were tested using different compositions of Nisin Z and LAE to see which variations would give the "best kill." After dipping the samples into the edible film composed with antimicrobials, some of the slices were vacuum packaged and chilled for up to a month, and other samples were frozen for 90 days.
"This research demonstrates, through proof of concept, that antimicrobial edible films work,” Cutter says. “So how do we get this type of packaging into a commercial application? That's the next logical step in the progression of this type of research."