What color do bananas emit under UV light?

Bananas emit blue light when exposed to UV light. This is because of a phenomenon called fluorescence, in which certain molecules absorb light energy and re-emit it at a longer wavelength, producing a visible glow. In the case of bananas, the compound responsible for the fluorescence is chlorophyll, which is also found in plants and gives them their green color.

When chlorophyll is exposed to UV light, it absorbs the energy and emits a blue light, which can be seen with the naked eye. This effect is most visible in ripe bananas, which contain more chlorophyll than unripe bananas. The blue glow is also more pronounced in the peel of the banana than in the fruit itself.

While the blue fluorescence of bananas under UV light may be interesting, it is not harmful to eat bananas that have been exposed to UV light. However, it is still recommended to store bananas in a cool, dark place away from direct sunlight to prevent overripening and spoilage.