Crab contains more histidine, which is easy to decompose and can produce histamine and histamine-like substances under the action of decarboxylase. Especially when crabs die, histidine decomposes faster. The longer the crab dies, the more histamine accumulates in the body. When histamine accumulates to a certain amount, it will cause poisoning if eaten.
Among all the toxins, ammonia is a very important part. Crabs can carry ammonia, which needs to start from its rich protein. Crabs contain a lot of protein. After its death, protein in the body will be decomposed into ammonia. After the dead crab is eaten into the human body, the excess ammonia must be discharged through the human body, which will do harm to health.
Extended data:
Taboos for eating crabs:
1, not suitable for eating raw crabs.
Crabs generally feed on animal carcasses or humus, so the body surface, gills and gastrointestinal tract of crabs are covered with all kinds of bacteria and sludge. Crabs often carry cysts of paragonimiasis and Vibrio parahaemolyticus. If it is not disinfected at high temperature, paragonimiasis will cause lung injury after entering the human body.
If Vibrio parahaemolyticus invades human body in large quantities, infectious poisoning will occur, which is manifested as intestinal inflammation, edema, congestion and other symptoms. Therefore, crabs should be steamed and cooked thoroughly, and generally heated for more than 30 minutes after boiling to play a disinfection role.
2, should not eat too much.
Even if you are greedy, you should endure it: because crab meat is cold, you can't eat more. People with spleen and stomach deficiency and cold should pay special attention to avoid abdominal pain and diarrhea. Abdominal pain and diarrhea caused by eating crabs can be taken with 15g warm Chinese medicine perilla, 5~6 slices of ginger and water.
References:
People's Network-Health What You Need to Know: Can Crabs Eat After Death?
References:
People's Network-You can't eat persimmons after eating crabs. Pay attention to five taboos.