A newly-created biodegradable packaging film may be able to control the growth of foodborne pathogens on seafood.
Catherine Cutter, professor of food science at Penn State, is part of a team developing a biodegradable film with antimicrobial activity that can kill foodborne pathogens on food surfaces.
“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,” Cutter told SeafoodSource.
Cutter said the team found that putting antimicrobials into a film product brought much higher levels of success than antimicrobial dips.
"If you just dip shrimp into any antimicrobial, it's not going to stick very well," Cutter said. "But if you put the antimicrobial into a film and then dip the shrimp into a solution [or] film and pull it out, that film is going to form around the shrimp. The film then releases the antimicrobials over time."
The researchers have previously had success testing edible and biodegradable films on beef and other proteins in other studies, and now Cutter is working with her team to test it on seafood. Cutter and her colleagues in Thailand recently ran a series of tests, which can prevent growth of salmonella and vibrio. Results of their study will be published in the February 2019 issue of the International Journal of Food Microbiology.
The team wanted to test the biodegradable film on seafood “because seafood is consumed much more than other proteins in Thailand,” Cutter said. She thinks it will be of use to the seafood industry because both vibrio and salmonella can survive long-term freezing.
The researchers tested the film – made with plant starch and antimicrobial compounds – on bigeye snapper and tiger prawns purchased from supermarkets in Thailand. After dipping the samples into the film with antimicrobials, some of the slices were vacuum-packed and chilled for up to a month, and other samples were frozen for 90 days.
The antimicrobial film was highly effective, Cutter said. When salmonella was inoculated onto bigeye snapper, and then it was treated with the film and refrigerated for 28 days, salmonella was reduced 99.9 percent. Similarly, salmonella was reduced 99.9999 percent on tiger prawn slices even after they were refrigerated for 21 days.
While the results of small-scale testing were successful, Cutter said more cost analysis and other research must be conducted before the film would be used on a commercial scale by the seafood industry.
“We are on the cusp of learning more about the economic implications of films for controlling pathogens. However, we need more cost analysis and other measures to determine the best ‘bang for the buck,’” Cutter said. “Putting biodegradable or even edible film on meat or seafood may be a feasible option.”
The results demonstrate that biodegradable packaging could be a good alternative to plastic packaging, which is typically not recycled, Cutter said.
