“Sugar-Glass” Wraps Use Viruses to Kill Bacteria and Preserve Your Food
Using viruses to kill bacteria. Alas, the irony!
With antibiotic resistance on the rise, bacterial contamination of food is becoming more problematic. Therefore, scientists have been looking for a way of incorporating phages into antibacterial food wrap, but it’s proven difficult to keep them alive.
Because phages are naturally found on fruits and vegetables and do not affect the odor, taste, safety or appearance of foods, scientists are investigating whether these “bacteria-eaters” could have an expanded role in promoting food safety. But incorporating phages into food packaging has been challenging. Drying them out so they can be added to various types of films can kill the viruses. Other methods for stabilizing phages are also problematic, requiring special handling or equipment.
But now, researchers at the McMaster University have embedded phages insoluble films known as “sugar glasses.”
Carlos D.M. Filipe and colleagues have developed an antibacterial “sugar-glass” coating in which viruses that destroy bacteria are embedded and are kept stable for up to three months. The coating could someday be used in the food packaging and processing industries to help prevent food-borne illnesses and deaths.
This new film consists of
either pullulan, which is a polysaccharide used to prolong the shelf life of fruits and eggs; trehalose, a sugar used as a stabilizing agent in freeze drying; or a combination of the two.While still in a liquid state, the phage-containing films were applied to butcher paper and allowed to air-dry overnight at room temperature.
When the paper samples were subsequently tested, the phages that were embedded in just pullulan or trehalose lost their bacteria-killing effect in one to two weeks. The phages that were embedded in the mixture of both, though, were still able to infect harmful bacteria such as Lysteria monocytogenes up to three months later.
