Imagine not having to play a guessing game with foods that are dangerously close to their expiration date but that still look and smell just fine. That is the aim for McMaster University researchers who have developed a method for determining whether or not meat and other foods are safe to eat.

A team of biochemists and mechanical and chemical engineers from the university have developed a transparent patch printed with innocuous molecules that will signal food contamination in real-time. The team believes that the patch could one day be incorporated into food packaging to monitor for pathogens such as E. coli and Salmonella, potentially replacing traditional “best before” dates altogether.

"In the future, if you go to a store and you want to be sure the meat you're buying is safe at any point before you use it, you'll have a much more reliable way than the expiration date," says lead author Hanie Yousefi, a graduate student and research assistant in McMaster's Faculty of Engineering.

Researchers envision that once the patch detects the presence of a pathogen, it would produce a signal in the packaging that a smartphone or other similar device could read. Because the DNA molecules that detect food pathogens can be printed onto the patch, researchers believe that mass producing the patch would be relatively easy and inexpensive.

"A food manufacturer could easily incorporate this into its production process," said Tohid Didar, an assistant professor of mechanical engineering and member of the McMaster Institute for Infectious Disease Research.

Additionally, researchers believe that the technology behind the patch would not be limited to the food and beverage industry but could find applications in the health-care industry as well, particularly as bandages that would signal a wound infection or as a wrap for surgical instruments to ensure that they are sterile.

The research is detailed in the journal ACS Nano.

To contact the author of this article, email mdonlon@globalspec.com