Why do potatos turn green when exposed to light (sticking out of the hill)?

Question

I've heard it is not safe to eat a green potato or one part green. True or not? Why? Can you cut the green off and eat it.

Answer 1

The green is chlorophyll because a potato is actually a modified stem and not a true root.

With the Chlorophyll the potato produces solanin, which is a powerful poison like in the nightshade family (which potatoes and tomatoes are part of.

Don't eat green potatoes.

Green potatoes can kill you.

Answer 2

Green potatoes contain a natural poison called solanine. the green color is chlorophyll, harmless by itself, but its presence indicates solanine is present in the potato. Research has shown that the poison is concentrated mainly in the green skin of the potato and very little in flesh of the potato. So cutting away the green portion, the rest should be safe to eat.                                                                                                             However, unless you really need the potato, I would discard it to be on the safe side. Most potatoes for sale have the green one culled unless an occasional one slips by. After you dig or buy your potatoes always store them in a dark place.

Answer 3

Basically potato is not part of root. Rather it is a stem. Thus, with availability of sun light, it's chlorophyll becomes   active and due to presence of chlorophyll in these exposed-out-of-soil potato look green.

* These potatoes are treated as poisonous and I'm not sure about the reason.

* I would expect some of our friends will be able to answer this point.

Answer 4

Green colour is indication of viral infection.