Ever wondered whether that vacuum-packed chuck steak or that chicken breast is still fresh? Looks can be deceiving, and the “best-before” date may be no guarantee. A group of German scientists claim they've solved the problem: embedded into food packages, a thin slip of film will change color when meat becomes spoiled.
Developed by the Fraunhofer Research Institution in Munich, the sensor film responds to the presence of biogenic amines. (Amines are the foul smelling molecules often produced by foods, especially meat and fish, when they decay.) Once a certain concentration of amines is released into the air inside the package, the indicator strip will change from yellow to blue.
While it won't solve the problem of the bacteria-laden meat we're all apparently eating, Fraunhofer scientists are working on broader applications for the technology, including a module that would allow workers in the food industry to test the freshness of food products directly.