This season is the peak time for sales of Chinese mitten crabs, a popular delicacy on dining tables. However, how much do people really know about these crabs? How long can a dead Chinese mitten crab be eaten?
What is a Chinese Mitten Crab?
The Chinese mitten crab, also known as the hairy crab, is a species of freshwater crab. It is widely distributed along the long coastline from the Liao River in the north to the Pearl River in the south of China, with the Yangtze River basin being the largest producer and having the most delicious taste. Generally speaking, the term "Chinese mitten crab" refers specifically to the hairy crab from the Yangtze River system. The authentic Yangcheng Lake Chinese Mitten Crab is characterized by its green back, white belly, intact pincers, yellow hair, and robust body.
How long can a dead Chinese Mitten Crab not be eaten?
Regardless of how long a Chinese Mitten Crab has been dead, it should not be eaten. This is because these crabs live in polluted ponds and have a large number of bacteria in their bodies. Live crabs can eliminate bacteria through metabolism, but dead crabs are unable to do so. Moreover, the bacteria in dead crabs multiply rapidly, causing the high protein content to deteriorate rapidly and leading to food poisoning.
Why can't dead Chinese Mitten Crabs be eaten?
After a Chinese Mitten Crab dies, it easily rots. The crab's body contains a substance called histidine, which decomposes into histamine when the crab is dying or already dead. Histamine is a toxic substance that accumulates in the crab's body as the time of death increases. This toxin is not easily destroyed, even when the crab is cooked. Therefore, it should not be consumed.
What are the risks of eating dead Chinese Mitten Crabs?
Eating a large amount of dead Chinese Mitten Crabs can cause symptoms such as vomiting, abdominal pain, and diarrhea. Therefore, it is not recommended to consume even partially dead crabs to avoid discomfort.
Note: The fact that dead crabs cannot be eaten does not mean that live crabs are completely safe. Some live crabs have a high infection rate and infection level of lung fluke larvae cysts. Once lung flukes enter the human lungs, they can stimulate or damage lung tissue, causing coughing, bloody sputum, and even paralysis if they invade the brain.
Therefore, it is best to eat crabs from clean rivers and avoid crabs from places like foul ditches.
Recommendation: Before eating crabs, it is necessary to remove the gills, heart, stomach, and intestines, as they contain bacteria, viruses, and mud.
How to safely consume crabs
Lung fluke cysts have a strong resistance and can only be killed by soaking them in water at 55℃ for 30 minutes or in a 20% saline solution for 48 hours. Eating raw crabs can also cause symptoms such as gastrointestinal inflammation, edema, and congestion. Therefore, steaming or boiling crabs is the most hygienic and safe way to consume them.
Note: When steaming or boiling crabs, be sure to cook them for at least 20 minutes after the water boils to ensure that the bacteria in the crab meat are killed.
How to determine if a Chinese Mitten Crab is dead
1. Pick up a bound Yangcheng Lake Chinese Mitten Crab and touch its eyes with your hand to see if it blinks. Blinking indicates freshness.
2. Take half a basin of water and put the bound crab in it to see if it breathes out bubbles. Bubbles indicate freshness. (Note: Do not leave the bound crab in the water for a long time, as it will quickly suffocate due to lack of oxygen in the water.)
3. Touch the crab's claws and straighten the smallest claw to see if it naturally bends back quickly. If it does, it is fresh.
4. Unbind the crab and see if it crawls. If it can crawl, it is lively.
Why can't dead river crabs be eaten?
Crabs live in water and like to eat decaying animal carcasses such as dead fish and shrimp. This can cause them to be infected with certain bacteria. Especially for river crabs, they mostly grow in polluted ponds and have a large number of bacteria both inside and outside their bodies. Live crabs can eliminate bacteria through metabolism, while dead crabs allow the bacteria to multiply rapidly, decompose the crab meat, and some bacteria even produce toxins. Eating such crabs can cause food poisoning, with common symptoms including nausea, vomiting, abdominal pain, and diarrhea. In severe cases, dehydration, electrolyte imbalance, convulsions, and even shock, coma, and sepsis may occur.
What to do if you get food poisoning from crabs
If someone experiences discomfort after eating crabs, they must immediately try to vomit the food from their stomach. If necessary, gastric lavage should be performed, and antibiotics and symptomatic treatment should be administered orally. In severe cases, the patient should be taken to the hospital for treatment.
In addition, there is a folk remedy that can be used: Crush 15 grams of garlic and soak it in cold water to remove the residue. Then add 25 grams of brown sugar and drink the mixture at once. Repeat every hour, drinking it three to four times. This remedy has certain effects.
