Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Food

Chemistry In Pictures

Chemistry in Pictures: Blue bananas

by Craig A. Bettenhausen
May 14, 2020

 

Green and yellow bananas up top, glowing blue bananas on bottom.
Credit: Angew. Chem. Int. Ed. 2008, DOI: 10.1002/anie.200803189

Colorblind human fruit-lovers face a problem at the grocery store: How can you tell if a banana is ripe if you can’t see green properly? Bernhard Kräutler and his team at the University of Innsbruck may have come up with an answer. Ripe bananas fluoresce under UV light. “Surprisingly, the blue luminescence of bananas apparently has been entirely overlooked. Most humans would even consider the idea of a blue banana to be unappetizing,” Kräutler writes in a paper on the research (Angew. Chem. Int. Ed. 2008, DOI: 10.1002/anie.200803189). As chlorophyll in banana peels and leaves breaks down during ripening, it produces a set of blue fluorescent compounds, which peak in concentration just as the fruit inside is peaks in ripeness. As the fruit continues to mature, the compounds break down further into nonfluorescent molecules. Kräutler suggests in the paper that the fluorescence may have evolved as a way to signal to banana-eating animals, many of which can see further into the UV than humans can, that the fruit was perfect to eat.

Credit: Angew. Chem. Int. Ed. 2008, DOI: 10.1002/anie.200803189

Do science. Take pictures. Win money. Enter our photo contest here.

A bar graph shows the prevalence of fluorescent compounds in bananas as a function of ripeness and it has little banana pictures at the top of each bar and it's just the cutest bar graph I've seen all year.
Credit: Angew. Chem. Int. Ed. 2008, DOI: 10.1002/anie.200803189
The Chempics team couldn't resist sharing this graph from the paper with you.

Click here to see more Chemistry in Pictures.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.