Researchers at the ever-prolific Fraunhofer Institute have developed a system based around metal oxide sensors to detect whether a fruit is ripe, green, or rotten.

The system is meant to be used primarily by food suppliers, so that they can automatically detect the best moment to deliver pieces of fruit to a store. By using the sensor to detect levels of gasses emitted from fruits (in the test case, a pineapple), they know exactly what condition the fruit is in. And the equipment is as sensitive as the stuff used in food laboratories.

Fraunhofer is currently trying to see if such a sensor could also be used to find the right time to slaughter a pig for pork, based on the animal’s smell.