Latest Issue of Science News


News

Blue halos of doom

Under ultraviolet light, rings around the brown spots in aging bananas may signal the transition from ripe to rotten

Ghostly rings of light surround the dying brown spots in overly ripe bananas, researchers report. The halos, which glow intensely blue under ultraviolet light, may mark the beginnings of cell death and may signal to animals such as apes that the bananas are ready for eating.

Bernhard Kräutler of the University of Innsbruck in Austria and his colleagues had already found that yellow bananas have a blue hue under UV light. Green bananas, on the other hand, don’t. The blue, the researchers knew, comes from a class of fluorescent chemicals that are produced and build up when chlorophyll breaks down.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

X
This article is available only to subscribing members. Join SSP today or Log in.