Every year, U.S. supermarkets lose roughly 10 percent of their fruits and vegetables to spoilage, according to the Department of Agriculture. To help combat those losses, MIT chemistry professor Timothy Swager and his students have built a new sensor that could help grocers and food distributor’s better monitor their produce. The new sensors, described in the journal Angewandte Chemie, can detect tiny amounts of ethylene, a gas that promotes ripening in plants. Swager envisions the inexpensive sensors attached to cardboard boxes of produce and scanned with a handheld device that would reveal the contents’ ripeness. That way, grocers would know when to put certain items on sale to move them before they get too ripe.
The researchers tested their sensors on several types of fruit — banana, avocado, apple, pear and orange — and were able to accurately measure their ripeness by detecting how much ethylene the fruits secreted. Swager has filed for a patent on the technology and hopes to start a company to commercialize the sensors. The system would be extremely cheap — about 25 cents for the carbon nanotube sensor plus another 75 cents for the RFID chip, Swager estimates.
