New sensor for testing food freshness could spell the end of expiration dates

No more guesswork
No more guesswork
Image: AP Photo / Mary Ann Chastain
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European researchers have developed a sensor that can determine if your food is still good to eat or should be thrown in the trash—regardless of what the expiration date says.

The plastic sensor circuit measures the food’s “environmental vitals” from within the packaging, and the resulting judgment on freshness can be read with a mobile phone. The researchers claim the cost is less than one eurocent per unit, much less than any similar sensor technology, but say it will take at least five years before the technology finds its way to grocery stores.

The circuit works as follows: A tiny sensor measures conditions like acidity levels. The sensor produces an analog signal that is converted into a digital signal and broadcast over an RFID radio. Some phones are already equipped to pick up an RFID signal, and many more will be in the future.

Other waste-reducing technologies are also currently in the works. Insignia Technologies, a Scottish company, recently launched a “smart label” timer that is triggered upon opening a food product’s packaging. One you activate the timer, the label’s color begins to change, indicating whether the food has just been opened, should be eaten soon, or is past its prime. But unlike the sensor circuit, the smart label is still based on a pre-determined expiration date rather than the food’s actual freshness.

One third of the world’s food is wasted each year, according to the United Nations. This sort of technology could put a huge dent in global food waste, not to mention indigestion rates.