Why does the shell of Crabs turn red when they are cooked?

Answer 1

The red pigment is the most stable component of the coloring in a crab shell. The greens, blues, and browns which darken the shell in a live crab are destroyed by cooking. The red pigment common to all shrimp, crab, and lobster shells is astaxanthin, a carotenoid (e.g., like Beta-carotene, the pigment that makes fruits red-orange). Astaxanthin was first identified in the exoskeletons of crayfish (Astacidea), hence its name. In crabs, as in many decapods, astaxanthin is not a free pigment, but is complexed with a protein called Alpha-crustacyanin, which alters the resonance of astaxanthin such that the complex acts as a blue-green pigment. As mentioned above, astaxanthin is heat stable, while the Alpha-crustacyanin protein is not, so boiling the crab shell denatures the blue-green Alpha-crustacyanin releasing the red-orange astaxanthin.

Answer 2

cause there blue first but there hot like when white be get hot they turn red but the crabs are hot and they turned red.

Answer 3

You should give 10 points to benninb. What a great answer!

Answer 4

why does anything turn red when warmed to a high temp

Answer 5

Don't you turn red when you are hot?

Answer 6

I love snow crablegs w/ melted butter, ketchup and lots of lemon
Bring it on!!!!!!!!!!!!!!!!!!!!!!!
And a nice glass of sweet tea too.

Answer 7

i agree with benninb

Answer 8

You'd get mad too!