A lobster's blood becomes which color after being exposed to air?

Lobsters are a family of large marine crustaceans. They have long bodies with muscular tails, and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.

Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper. The blood is colorless until exposed to oxygen when it turns a tint of blue. The blue hue is due to the hemocyanin, which the lobster’s body uses to transport oxygen. Human’s red colored blood is due to iron being the oxygen carrier. When lobsters are cooked the blood turns to a white, opaque color and has a gel like consistency.

Recently, scientists have found that hemocyanin works as a powerful stimulant for the immune systems. For example, experiments show the substance can reduce the viral load of herpes simplex virus-infected cells, according to documents filed with the United States patent office.