Shrimp, when cooked, turn this lovely shade of pink. I swear that pink hue has a direct connection to my taste buds. I see that color and I want to pop one of those succulent little morsels into my mouth and savor their deliciousness. They look pinkalicious as my grand-daughter would say. Yet a few minutes earlier those same shrimp were a pale gray-blue and did nothing to fuel my taste buds. Hmm, that got me thinking. What makes shrimp turn pink when cooked?
Shrimp, lobsters, and crabs are crustaceans. This means they have an external skeleton, an exoskeleton. In short, they have a hard shell. In their water environment these creatures exhibit a blue-green, or a blue-gray color. This color is from the protein complex of the outer shell, which dominates the creature’s individual color. Within this protein covering lies a hidden pigment called astaxanthin. The protein covering camouflages this hidden pigment. Astaxanthin is a member of the carotene family. You have heard of carotene. Carrots and other fruits and vegetables contain carotene, which gives them their orange/red color.
These protein chains are not heat stable. The protein wrappings uncoil as soon as crustaceans are heated. The result is the red-orange astaxathin molecules are released. These pigments related to carotenes (orange-red) are heat stable. So now the astaxonthins can now display their unique color that we equate with delicious!
Who knew? Not me! Now we do!