Blue Bananas

[kds315]

I read on the net, that scientists in Innsbruck, Austria and Columbia University, New York have found, that bananas emit blue fluorescence light when radiated with UV light of 365nm, but depending on the degree of ripeness of the banana. This is caused by breaking down of the green chlorophyll and these byproducts accumulate in the peel. So why not try to make that visible?

The normal bananas as we all know them in visible light:

Now radiated with my 365nm Nichia UV LED and with UV blocking filter in front of the camera lens:

Just looking at the blue channel makes it even more visible:

So obviously bananas do fluorescence and it gets very obvious that the one in front is the ripe one, wheras the one in the back is the green, unripe banana. So have your UV light ready when shopping for bananas next time...!!

 

[mousedeers]

Interesting thanks for the infos.

 

[JeffryZ]

I have some blue bananas but I made them that way in Photoshop. I don't remember everything I did but I did do a bunch of selective coloring. I think I was sliding the hue/ saturation slider almost all the way to one side to get the blue/ green.

The original: