New lacquer-based antibacterial active film keeps food fresher, longer
By Ben Coxworth
October 7, 2010
Researchers from Germany’s Fraunhofer Institute for Process Engineering and Packaging have developed a new type of food packaging film that kills food-inhabiting bacteria. While antimicrobial polymers in food packaging have been around for some time, the new material is unique in that it incorporates sorbic acid that has been dissolved into a lacquer, which is then deposited onto the film. When that lacquer first touches the food, a timed release of the acid begins, which neutralizes a significant number of the microorganisms on the food’s surface. The result, according to the researchers, is the ability to keep meat, fish and cheese fresher for longer.
Fraunhofer food chemist Carolin Hauser chose sorbic acid not just because it kills germs, but also because it’s non-toxic, non-allergenic, water-soluble, and doesn’t have a strong smell or taste. It is already used as a preservative in many foods, and is considered environmentally-safe, as it breaks down rapidly in soil.
Hauser used fresh pieces of pork loin for her evaluation of the film. She contaminated each of them with 1,000 colony-forming units of the E. coli bacteria, then wrapped some of them in regular film and some in her product. Differences in color between the two groups were apparent after several days in an 8C (46F) fridge. When she did a microbial analysis, she discovered that the E. coli population on the pork wrapped in her film had decreased to about one quarter its original size.
“After a week, the total germ count on the surface had decreased significantly compared to the meat packed in untreated film,” she said. “This indicates that our active film is suitable for maintaining the freshness – and above all the safety – of meat preparations, cheeses, fish fillets and other cold cuts.”