. As fruit matures, it releases ethylene which is a gas that initiates the ripening process. Once the ripening process begins, more ethylene is released and the process accelerates. Currently produce warehouses that store and ripen fruit make use of gas chromatography and mass spectroscopy systems that cost about $1,200 to measure the levels of ethylene which in turn reveals the ripeness of the fruits in storage.
A scientist from MIT has reportedly been working on something that might change that soon.
Ubergizmo, Inexpensive Nanotube Sensor Measures Ripeness of Fruit
