crab, and shrimp are all crustaceans, which means they
have an exoskeleton (or external skeleton) that appears
as a hard shell or crust. In the sea, the shells of crustaceans
display a variety of colors, but when crustaceans are
uncooked, the green-blue hue of the protein complex of
the outer shell predominates.
In lobsters, crab, and shrimp, however, a pigment called
"astaxanthin" lies hidden, camouflaged by a protein
covering. Astaxanthin is a member of the carotene family
of pigments, which are responsible for coloring many
of the yellow and orange (or "carotene") fruits and
Because these protein chains are not heat-stable, their
protein wrapping uncoils as soon as crustaceans are
put in boiling water. Voila! Red-orange astaxanthin
molecules are released. Because pigments related to
the carotenes are stable, the astaxanthins now display
their unique deep hues that are so appealing.
Those who enjoy the delicacy of these gifts from the
sea know their flavors are as appealing as their coloring.
The dramatic color change adds one more facet to the
fascination of learning about the foods we consume.