Why do crabs, lobster, and shrimp shells turn red once cooked?

I got this - I am from MAINE!



Quoting Dr. Bayer from Maine Lobster Institute: The color of lobsters is due to natural pigments called carotenoids.



The primary pigment in American lobsters is astaxanthin, a red pigment found also found in some bird feathers.



In cool temperatures, this red pigment combines with other proteins in the shell, and the shell takes on the color of the proteins. Usually, wild lobsters are a greenish-brown that often looks black in water.



Heat destroys the structure of the proteins attached to the red pigment. That pigment is more stable in heat, and once free of the protein that was bound to it, can then shows its true colors.



Lobsters turn red when they're cooked regardless of their original color. But there may be subtle differences. Boil a blue lobster, says Bayer, and ``you get a pinkish color. It's not as intense.''



You may have read about ``Lincoln,'' a rare albino lobster caught last month in Maine's Casco Bay. This, Bayer says, is a lobster that lacks all pigment. Boil it, he surmises, and you'll still have a whitish-gray lobster.



(Gross. Imagine getting a WHITE lobster.)

Why do crabs, lobster, and shrimp shells turn red once cooked?
Quoting the source: "The color change is quite similar to that of the leaves of most deciduous trees, where the orange and yellow colors already present in the leaves are masked by the assertive green of their chlorophyll. When the chlorophyll breaks down in the fall, the other colors become visible.



Similarly, many lobsters, crabs, and shrimp have a variety of different colors present in their shells. The pink or red color is the pigment astaxanthin, but its molecules are wrapped up in dark protein chains. So the shells are dark. Whenever you cook a protein, though, it uncoils, or denatures, and in the case of these shellfish, that frees the red pigment and the shell changes color. "
Reply:because the blood vessels burst, i think
Reply:if you were thrown into boiling water, you'd turn red too LOL
Reply:i have always wondered that



great question?
Reply:it is part of the natural pigment, when they are a live there color can change vary slightly when cooked the red color is the pigment.
Reply:its probably caused by some chemical reaction
Reply:The same reason why your skin turns red if it comes into contact with really hot water.
Reply:Yeah, like an earlier dude said.. what color would you turn, if some mofo threw you in a pot of boiling water?
Reply:once
Reply:Not sure. But they will also turn red when exposed to an acid such as lemon juice or vinegar (it kinda cooks it)