Why do crabs turn red when cooked?

The color of the body surface of shrimp and crab is mainly determined by the pigment cells in the dermis of its crustacea, usually there are many pigment substances on the surface of the shell of shrimp and crab, these pigments are basically blue-black, which contains a pigment called astaxanthin, which usually combines with protein, so it is not red.

When crabs and shrimps are heated at high temperatures, many pigment substances will be destroyed one by one, because astaxanthin is more stable and not easy to be destroyed at high temperatures, so at this time astaxanthin can be separated from the protein, thus showing its original red color, which is also magically highlighted at this time, so the shrimp and crabs we see at this time are mainly red. However, astaxanthin is not evenly dispersed on the surface of shrimp and crabs, and we can see that the red parts are generally concentrated on the back of shrimp and crabs, while their abdomen is rare, because astaxanthin is very small in its abdomen.

Crab is a kind of food that many people love to eat, and it is delicious and mouth-watering. Interestingly, the back of a live crab is blue-black, but once cooked, it turns a vivid orange-red.

It turns out that crabs belong to the crustacean family, and their color is mainly determined by the pigment cells distributed in the dermis below the carapace. Of these pigment cells, the cells containing astaxanthin are the most numerous. Astaxanthin is a carotenoid, which is originally orange-red and can be combined with different kinds of proteins to change to other colors such as blue-violet or turquoise.

When the crab is heated, the protein is destroyed and separated from astaxanthin, while the other pigments are destroyed and decomposed at high temperatures, only astaxanthin is not afraid of high temperatures and is not destroyed, and when other colors disappear, the red color is revealed. So, the boiled crab will turn red.

On the formabetha of crabs, the distribution of astaxanthin is also uneven. Wherever there is a lot of astaxanthin, such as the back, the crab looks extra red after it has been cooked; In places with less astaxanthin, such as the lower part of the crab legs, the red color is lighter; Since there is no astaxanthin in the abdomen of crabs, it will not turn red no matter how many times it is steamed.

Why do boiled crabs turn red?

The pigment area of the exoskeleton of shrimp and crab contains a protoastaxanthin, which belongs to carotenoids, which is originally orange-red, but can be combined with different kinds of proteins, and will change to other colors such as red, orange, yellow, green, blue-violet, etc. When the protein is destroyed, denatured, or separated from the original astaxanthin, the color changes to the original orange-red, so when the shrimp and crab are cooked, the shell will turn red.

Because the shell of the shrimp contains astaxanthin and astaxanthin, the pigment is active when the shrimp is alive, so it shows blue-black. Astaxanthin is unstable and will be destroyed when it is heated, but astaxanthin is very stable, so it shows the red color of astaxanthin after cooking. This is also true for crabs that turn red after boiling.

Crabs turn red when cooked because astaxanthin turns red when exposed to high temperatures. Live crabs are generally cyan in color and turn red when they are cooked. This is mainly because there is a pigment called astaxanthin in the crab's body, which is originally red, but it can bind to proteins, so it is difficult to show its original color.

When the crab is cooked, the astaxanthin separates from the protein, and the astaxanthin shows its original color, and the crab turns red.

Crab has been a delicacy on people's tables since ancient times, and people divide crab meat into "four flavors". They are "thigh meat", "shank meat", "crab body meat" and "crab roe". Among them, the meat quality of the "thigh meat" is not delicate at all; The meat of "shank meat" is delicate; "Crab meat" is white and crystalline; "Crab roe" is rich in nutrients, containing protein, fat, phospholipids, vitamins and other nutrients.

Crabs can be eaten all year round, but only in autumn the crab meat is the most tender. The reason for this situation is largely related to the growth of crabs, which are the best time of the year for crabs to grow, so the crabs that are marketed in autumn are thick, fatty, and delicious. Whether it is cream crabs, meat crabs, or hairy crabs, they all grow best in autumn.

Astaxanthin turns red at high temperatures. The dermis under the crab's carapace contains four pigment cells: red, yellow, blue, and cyan, which usually appear dark gray. Among them, the red pigment, also known as shrimp red pigment, belongs to carotenoids.

When the crab is heated to 100°C, the other pigments are decomposed and disappear, except for the carotenoids, which give the cooked crab a bright orange red color.

Because carotenoids accumulate more in the crab's head, chest, and feet, and have very little in the abdomen, the cooked crab's belly is white.

Crabs are crustaceans whose bodies are protected by a hard shell and breathe by their gills. Common crabs include pike crab, open-sea pike crab, blue crab and Chinese mitten crab (river crab, hairy crab, water crab with clear file and slag).

Crabs are rich in nutrients, and they are rich in protein, fat, phosphorus, calcium, iron, and vitamin A and vitamin B1.

Summary. Dear, the change of crab steaming and turning red is: astaxanthin turns red when exposed to high temperatures.

What is the change in the crab steaming and turning red.

Dear, the change of crab steaming and turning red is: astaxanthin turns red when exposed to high temperatures.

Live crabs are generally cyan in color, and when we cook them, they turn red. This is mainly because there is a pigment called astaxanthin in the crab's body, which is originally red, but it can bind to proteins, so it is difficult to show its original color.

Astaxanthin is also known as astaxanthin and astaxanthin. In 1933, a purple-red crystal was extracted from shrimp, crab and other aquatic products, and it was later determined that it was a carotenoid closely related to astaxanthin, so it was named astaxanthin. It is widely found in organisms such as shrimp, crabs, fish, birds, certain algae and fungi.

Crabs are crustaceans whose bodies are protected by hard shells. Crabs belong to the animal kingdom, the phylum Arthropods, Crustacea, Decapods, and reptiles. Crabs breathe by their gills.

In terms of taxonomy, crabs are the same kind of animals as shrimps, lobsters, and hermit crabs. The vast majority of crab species live in or near the sea, although there are some that live in freshwater or on land.