So why do these crustraceans turn red when they're cooked? Lobsters and crabs have a pigment called astaxanthin in their shells, which has the ability to absorb blue light, making the shell appear red under certain conditions.
Once you put a crab or a prawn in a pot of boiling water or on a grill, heat destroys the crustacyanin protein. Then, the orange-ey astaxanthin is released, turning the shell of the crustaceans bright red. In fact, the degree of colour change tells you if the seafood is properly cooked.
Fresh blue crab is blueish gray, but after a few minutes in boiling water, it turns a vibrant shade of red. At that point, you know it's just about time to take it off the heat.
When astaxanthin binds with a complex of proteins in the shell called crustacyanin, the reaction give the lobsters their natural dark blue, brown or gray color. Put a lobster in a pot of scalding water, however, and the crustacyanin denatures; astaxanthin is released and reverts to its orange-red state.
Heat destroys the protein coating, and when the animals are cooked, the astaxanthin molecules are released, thus changing the color of the crustaceans.
The pigment responds strongly to heat, though: Once you dump a crab or a lobster in a pot of boiling water, it's body chemistry changes: The pigment—astaxanthin—gets separated from the membrane—the crustacyanin—transforming your dinner into that ruby-hued tone we know so well.
If you have a female crab and you see bright orange stuff inside, that is edible. It's the roe or eggs, also called "coral" in shellfish.
A sound can emit from the shells of the lobsters — a high-pitched sound — but it's due to steam escaping through a fissure in the shell, not the lobsters 'screaming,'” she explained. This doesn't necessarily mean the cooking process is pain-free for the lobster.
Whether it is believed the lobsters experience pain or not, killing the lobster just before cooking is the preferred method. Perhaps this is for the benefit of the cook as a way to minimize trauma since most people are disconnected from the killing of animals they eat.
Contrary to claims made by seafood sellers, lobsters do feel pain, and they suffer immensely when they are cut, broiled, or boiled alive. Most scientists agree that a lobster's nervous system is quite sophisticated.
Frozen crab legs are often precooked, so you're just reheating them in the boiling water. If that's the case, be careful not to overcook them, as the meat will toughen and lose its delicate flavor.
A favored method of preparing fresh crabs is to simply boil them alive. A longstanding related question: Do they feel pain? Yes, researchers now say. Not only do crabs suffer pain, a new study found, but they retain a memory of it (assuming they aren't already dead on your dinner plate).
Around one in ten million lobsters are naturally red before cooking. Apparently these lobsters aren’t actually mutants. They are the same as blue and yellow lobsters, but they just have more red pigment. This manifests with red exoskeletons.
Despite its great numbers, Christmas Island red crabs are not considered edible, at least not edible to humans.
Claw. Claw meat is the dark pink meat that comes from the swimming fins and claws of the crab. It has a stronger taste, and is less expensive than the white color meat grades.
The reaction of astaxanthin with the protein complex gives the creature its dark blue colour. But crucially, when the lobster is cooked the protein is denatured and the astaxanthin is released and reverts to its orange-red state.
In 1900 the US passed the Lacey Act. It was a law meant to protect plants and wildlife, which it did. But it also eventually made it a federal crime to boil a live lobster.
Why Do People Cook Lobsters Alive? Boiling lobsters alive is a way to reduce the risk of food poisoning from bacteria that live in their flesh and that quickly multiply on their carcasses, according to Science Focus. Plus they have been deemed tastier and better presented on the plate when cooked this way.
Lobsters and other shellfish have harmful bacteria naturally present in their flesh. Once the lobster is dead, these bacteria can rapidly multiply and release toxins that may not be destroyed by cooking. You therefore minimise the chance of food poisoning by cooking the lobster alive.
In reality, freezing and thawing live lobsters may be safe, but it simply isn't worth the risk of toxins developing as a result of the process. Safety aside, freezing and thawing lobster prior to cooking it will lead to enzymes leaching into the meat, resulting in a mushy, unappetizing texture.
A lobster does not have a complex circulatory system like we do. Instead of a four-chambered heart it has a single-chambered sac that consists of muscles and several openings called ostia.
Research has clearly shown that lobsters, crabs, and other crustaceans can and do experience pain. Scientists have shown that their reaction to painful stimuli is more than just a reflex response and instead, they learn from painful stimuli and change their behavior.
Those who enjoy cooking and eating crab should simply take precautions not to eat the viscera, located under the crab's back, and avoid using whole crabs in soups and other dishes.
Other types of seafood, like shrimp, crab, scallops, eel and octopus are also widely and safely eaten raw.
The innards, if you can catch them before they fully congeal, are very good to eat straight from the shell.