A new portable sensor could detect gas emitted from rotting meat, allowing consumers to easily determine if it is safe to eat.
The sensor relies on modified carbon nanotubes that can be deployed in "smart packaging," Massachusetts Institute of Technology reported. Besides protecting people from food poisoning, the innovation could also help cut down on food waste.
"People are constantly throwing things out that probably aren't bad," said Timothy Swager, the John D. MacArthur Professor of Chemistry at MIT.
The sensor works because when carbon nanotubes are chemically modified they can carry electrical current changes in the presence of a specific gas. In this case the team modified the nanotubes with metal-containing compounds called metalloporphyrins.
"We use these porphyrins to fabricate a very simple device where we apply a potential across the device and then monitor the current. When the device encounters amines, which are markers of decaying meat, the current of the device will become lower," said lead author and graduate student Sophie Liu.
The researchers tested the sensor on pork, chicken, cod, and salmon. They found all four types of meat stayed fresh for over four days when refrigerated, but decayed at various rates if left out in the open.
There are several potential advantages in having an inexpensive sensor for measuring, in real time, the freshness of meat and fish products, including preventing foodborne illness, increasing overall customer satisfaction, and reducing food waste at grocery stores and in consumers' homes," said Roberto Forloni, a senior science fellow at Sealed Air, a major supplier of food packaging, who was not part of the research team.
The findings were published in a recent edition of the journal Angewandte Chemie.