Crabs contain a substance called proanthocyanidins. Boiled crabs will be heated, and astaxanthin will turn red at high temperature. The choice of crab should be the one with blue-black shell, full of vitality and clean abdomen. If it is light and smelly, it belongs to a poor crab.
Once crabs and shrimps are put into boiling water or barbecue pits, their heat will destroy their protein. Then, the orange astaxanthin is released, making the shell bright red. In fact, according to the different colors, you can see whether the seafood is cooked. If the color is not particularly red, it means it is not ripe enough.
The origin of crabs
Crab names come from two sources. A method named after "grasping crabs with fingers". In the crab catching season, every day when the sun goes down, crab catchers build small doors (also known as "crab sales") with bamboo or reeds in the guide room in the lake or harbor. At night, small lights are hung on the gate, flashing and dancing like stars. Crabs have phototaxis characteristics. When they saw the light, they scrambled to climb the gate. Crab catchers can be "watched by one person" as long as they keep the light. You can catch dozens of pounds in one night.
This kind of crab caught by the sluice is called "Zhaxie" in Wu dialect, and Yangcheng Lake crab element is famous for its big body, among which the one that can climb the sluice is bigger, about 200-250 grams, so the word "big" is added before "Zhaxie" to show the difference. Beauty is referred to as "Yangcheng Lake Hairy Crab" or "Hairy Crab".