Using technology to sniff out food that's gone bad isn't a new idea – we've seen sensors that use carbon nanotubes to detect spoiled meat, and smart caps that can spot bad milk. Now, researchers in the United Kingdom have successfully identified the chemical signature of ripening mangoes. The findings could be extended to other fruit, and might one day revolutionize how everyone from farmers to supermarket workers tell if their fruit is ready.

Mangoes are one of the most popular tropical fruits in the world, with the UK alone importing some 60,000 tonnes of them every year, creating a market worth in excess of £70 million (US$101 million).

With that much fruit moving around, it's important for both those growing the produce, and those selling it, to be able to tell whether it's ripe without actually having to taste it. Following new research conducted at the UK's University of Leicester, that might now be possible.

The team was able to determine the chemical signature of the fruit ripening in real time, using an "electric nose" to look for compounds given off by the produce. Using the popular Tommy Atkins mango species, as well as Keitt mangoes, the researchers were able to detect, in particular, an increase in ester compounds when the fruit was over-ripe.

Determining the detailed chemical signature of fruit as it ripens isn't just an impressive feat, but the knowledge could also lead to some extremely useful real-world devices. Perhaps most obviously, it could allow for the creation of non-destructive, hand-held electronic noses – similar to the one used in the study – that can assess fruit ripeness throughout the process of growth and distribution.

"This work has great potential for small devices to detect fruit ripeness and could be expanded to a range of different fruits," said lead researcher Professor Monks.

Looking forward, the team is looking for commercial partners who are interested in developing such uses for the research. Full findings of the work are published online in the journal Metabolomics.