"Why Do Lobsters Turn From Black To Red When Cooked...???"
"Q. Why do lobsters turn from black to red when cooked? Does the effect
have practical applications in business or medicine?
A. The color change was explained on a molecular level by 2002
research done in England, and other researchers suggest that the way
the pigment, called astaxanthin, is hidden until the lobster is heated
may have a medical application in delivering drugs.
Free astaxanthin appears red or orange because it absorbs blue light.
Researchers led by John Helliwell, working with low-intensity X-rays
at the Daresbury Laboratory in Warrington, found that when astaxanthin
was held in the embrace of protein molecules in the shell of a live
lobster, its color was masked, changing its light-absorption
properties and giving the lobster its dark, mottled appearance. But
heat makes the protein, called beta-crustacyanin, change shape, so
that its subunits relax their bonds with the pigment, allowing the red
color to appear.
Astaxanthin is found in many marine animals, like shrimp and fish, and
is also responsible for the pink color of flamingos that feed on
crustaceans rich in the pigment. It is a very active antioxidant.
Astaxanthin is not soluble in water, and scientists plan to study the
way it bonds to beta-crustacyanin in the hope that it may point to a
way to deliver non-water-soluble drugs..."