Nanoda
January 1, 2017, 11:24pm
1
Just playing with my UV flashlight, thought it was kinda interesting. I don’t have any other information to add; a brief Google search shows this is a known phenomenon, but probably doesn’t matter enough for anyone to figure out exactly why.
I have no idea why either. On a related note, tonic water with Quinine in it will also glows under UV light.
This is why I bring my own bananas to hotels
Off topic, but interesting, is the fact that the foreheads of male parakeets fluoresce under UV light. It’s how they attract mates, since birds can see in the ultraviolet range.
Also, if you point an infrared remote control at the camera lens on your phone, you can see the light it emits in your viewfinder.
Nanoda:
Just playing with my UV flashlight, thought it was kinda interesting. I don’t have any other information to add; a brief Google search shows this is a known phenomenon, but probably doesn’t matter enough for anyone to figure out exactly why.
Thank you for pointing out a fluorescence I was previously unaware of.
But a quicj search shows that someone, indeed, has looked into exactly why it happens:
Fluorescent chlorophyll catabolites in bananas light up blue halos of cell death
Simone Mosera,b,
…
Abstract
Breakdown of chlorophyll is a major contributor to the diagnostic color changes in fall leaves, and in ripening apples and pears, where it commonly provides colorless, nonfluorescent tetrapyrroles. In contrast, in ripening bananas (Musa acuminata) chlorophylls fade to give unique fluorescent catabolites (FCCs), causing yellow bananas to glow blue, when observed under UV light. Here, we demonstrate the capacity of the blue fluorescent chlorophyll catabolites to signal symptoms of programmed cell death in a plant. We report on studies of bright blue luminescent rings on the peel of very ripe bananas, which arise as halos around necrotic areas in ‘senescence associated’ dark spots. These dark spots appear naturally on the peel of ripe bananas and occur in the vicinity of stomata. Wavelength, space, and time resolved fluorescence measurements allowed the luminescent areas to be monitored on whole bananas. Our studies revealed an accumulation of FCCs in luminescent rings, within senescing cells undergoing the transition to dead tissue, as was observable by morphological textural cellular changes. FCCs typically are short lived intermediates of chlorophyll breakdown. In some plants, FCCs are uniquely persistent, as is seen in bananas, and can thus be used as luminescent in vivo markers in tissue undergoing senescence. While FCCs still remain to be tested for their own hypothetical physiological role in plants, they may help fill the demand for specific endogenous molecular reporters in noninvasive assays of plant senescence. Thus, they allow for in vivo studies, which provide insights into critical stages preceding cell death.
http://www.pnas.org/content/106/37/15538.full
Moser, Simone, et al. “Fluorescent chlorophyll catabolites in bananas light up blue halos of cell death.” Proceedings of the National Academy of Sciences 106.37 (2009): 15538-15543.
According to Google Scholar, it’s been cited 48 times.
November 25, 2009—For bananas, the “angel of death” wears a blue halo.
Seen under ultraviolet light, a ripening banana’s brown spots are each ringed by an eerie blue glow that marks where the cells in the peel are dying, according to a recently released study.
The glow comes from substances known as fluorescent chlorophyll catabolites, which are produced by the breakdown of chlorophyll in plants that are undergoing programmed cell death, or senescence.
(See related pictures of animals glowing for science.)
In plants, senescence causes fruit to become ripe and tree leaves to change color in the fall, while in humans, programmed cell death is linked to many of the degenerative diseases associated with aging.
By watching bananas under UV light, researchers can actually watch cell death in action and track its progress at the molecular level—perhaps a first step in better understanding plant life cycles.
“It’s a completely new way to look into a critical process in a cell’s life,” said study co-author Bernhard Kräutler, a professor of organic chemistry at the University of Innsbruck, Austria.
As a bonus, he added, the research can be done without wasting any tasty fruit: “We can measure this phenomenon on the intact banana and study it—and eat the banana later.”
Or here: Ripe bananas glow bright blue | News | Chemistry World
If I can find a roll of Wint-O-Green LifeSavers™, I’ll show you guys sumthin’ really cool.
