New electronic nose detects fruit ripeness

A new electronic nose designed to detect ripeness could save millions of pounds each year in preventing the wastage of fruit and vegetables, according to researchers at the Massachusetts Institute of Technology.

The team, lead by chemistry professor Timothy Swager, has built sensors that can detect small amounts of ethylene – a gas that promotes ripening in fruit. Fitted to cardboard boxes of produce, their ripeness could then be assessed using a hand-held scanning device.

“If we can create equipment that will help grocery stores manage things more precisely and maybe lower costs by 30%, that would be huge,” said Swager.

Very expensive

Fruit distributors monitor ethylene levels in warehouses using gas chromatography or mass spectroscopy units, which cost about $1,200 each. “Right now, the only time people monitor ethylene is in these huge facilities, because the equipment is very expensive,” he said.

But Swagger has filed a patent on technology focusing on carbon nanotubes, which he hopes will slash the cost. He plans to add a radio-frequency identification chip to the sensor so it can communicate wirelessly with a hand-held device to monitor ethylene levels.

“This could be done with absolutely dirt-cheap electronics, with almost no power,” he said.

The sensors are described in the journal Angewandte Chemie.