One reason the U.S. wastes 40% of all the food it harvests is that we don’t have a good handle on the status of that food. As consumers, we rely largely on best before and use by dates that are notoriously conservative, and often flat-out wrong. Actual food decays at variable rates that aren’t reflected in that information.
That’s why new types of food quality sensors could be so useful. If we can assess the actual state of each food item, that should allow us to make more informed choices and thus manage our fridges better. All things being equal, better information ought to lead to better decision-making.
One promising technology: the sensors being developed by Timothy Swager’s lab at MIT. Swager is testing an electrically-conductive material that changes resistance in the presence of gases called amines, which are released when food starts going bad. By reading that resistance from outside a package, you can figure out how edible the food is inside.
“You can put in tags about the size of business cards with an antennae, and then power them and read them with a smartphone,” Swager says. “You can have the sensor buried in the packaging where it’s not even obvious, and you can read it with a near-field communication device.”
The device could be several inches away, like with a contactless payment or ticketing system. The sensor inside the packet contains high-tech nanotube material that reacts to the amines. It’s really nothing more than two contact points with a conductive strip running between.
Swager has set up a company to commercialize the technology and he expects to do the first demonstrations to interested clients this summer. The first applications are likely to be for food workers working with meat and fish, but there’s no reason why consumers shouldn’t get their own devices in due time.
There are efforts to create visual clues for food status. But Swager says his method is better because it doesn’t rely on perception: it produces hard data that can be logged and tracked. And it also has potential to be very cheap.
“The resistance method is a game-changer because it’s two to three orders of magnitude cheaper than other technology. It’s hard to imagine doing this cheaper,” he says.