Lead researcher and chemist Paul Monks stands with a mango deemed ripe by his newly developed "electronic nose." Photo by University of Leicester

LEICESTER, England, May 10 (UPI) -- An unripe mango is unpleasantly metallic and bitter in taste. A ripe one is gloriously sweet. The fine line between unripe and ripe can be difficult to identify, but researchers at the University of Leicester have managed to "sniff" it out.

In a new study, published this week in the journal Metabolomics, scientists describe the chemical signature of a ripe mango.


"Mangoes are one of the most important and popular tropical fruits with India producing approximately 40 percent of the world's supply," lead researcher Paul Monks, a professor of chemistry at Leicester, explained in a news release. "The U.K. imports in excess of 60,000 tonnes of mangoes into the U.K. and the market is worth more than 70 million British pounds."

Monks and his colleagues designed an "electronic nose" capable of identifying the volatiles released by mangoes as they ripen. The analytical process is called metabolite profiling.

"In particular, the work showed an increase in ester compounds -- the smell of pear drops -- was a particular marker of over ripe fruit," Monks said.

Pear drops are a boiled sweet popular in Britain, which combine sugar and flavorings like isoamyl acetate and ethyl acetate.

Researchers say theirs is the first device able to sense a mango's ripeness on the fly.