Vienna, Sep 8 (DPA) Ripe bananas glow blue in ultraviolet light, possibly helping monkeys to spot choice fruit, Austrian researchers have found in a study.

'When brown spots develop, blue halos appear around them,' said Bernhard Kraeutler, an organic chemist at the University of Innsbruck who published the work of his team in the US journal Proceedings of the National Academy of Science, Monday.

When bananas ripen, the green pigment chlorophyll breaks down and causes the fluorescent blue colour.

As the blue disappears after a few days when the banana turns fully brown, it may help animals attuned to spotting it in the dense of the jungles to see when the fruit is ripe, the researchers say.