Research shows that such vacuum-packed foods do not have oxygen in them to help keep them fresh and boost their shelf life. The condition can harbor Listeria monocytogenes, a bacterium responsible for a kind of food poisoning that kills 25 percent of the people it infects.
According to the U.S. Food and Drug Administration (FDA), Listeria can grow even in the cold temperatures of refrigerators, a trait which is not seen in other bacteria. The microbe has been linked with foods such as raw milk; ice cream; soft-ripened cheeses such as feta, Brie and Camembert; hot dogs; raw and deli meats; raw vegetables; raw and cooked poultry; and raw and smoked fish.
Food microbiologist Tine Licht told LiveScience, "Avoiding vacuum packaging would lead to other problems with bacterial growth, so I'm not advocating that. But our work does help devise models predicting risk of food-borne disease."
Researchers from Denmark show that Listeria can get 100 times more invasive when they are provided oxygen. The research, which appears in June 14 of the online journal BMC Microbiology, also warns that the germ can be harbored inside the gut that has no or less oxygen.
