Some time ago, two "fat brothers and crabs" in Beijing were exposed by reporters to sell dead crabs as live crabs.
While strongly condemning the merchants, many netizens asked-
What are the hazards of eating dead crabs?
How long does it take for crabs to die before they can eat?
How long can cooked crabs be kept?
......
While giving children delicious food, we should also pay attention to safety and give them crabs. You should know this knowledge.
First, why not eat dead crabs?
High risk of poisoning
After the death of animals, the bacterial reproduction in digestive glands may lead to the spoilage of the whole food. As an omnivore, crabs are particularly risky.
There may be many bacteria in the food it eats. After death, bacteria will multiply rapidly and corrode crab meat.
In this process, not only the taste and taste of crab meat are greatly reduced, but also some biogenic amines harmful to human body are produced, which cannot be removed even if heated at high temperature.
Some biogenic amines are very toxic. A few milligrams may cause poisoning, which may lead to vomiting, diarrhea, allergies and other symptoms, and may lead to shock and organ failure in severe cases. Therefore, its content should be strictly limited.
Therefore, it is really necessary to pursue the freshness of crabs. Even many online shops selling crabs will make promises of "guarantee freshness" and "compensation for dead crabs".
How long can I die before I can eat?
Some people think they spend a lot of money on crabs. If they die, they throw them away. Is there a time limit for eating them in a short time after death?
If we can know the time of death, it is acceptable in a short time.
Someone has done experiments. At room temperature, the histamine content of hairy crabs increased from 3 mg/100g to 6 mg/100g after standing for 3 hours.
In a few hours, it will grow to 7 or 8 mg, which may cause slight poisoning.
If it is completely refrigerated, it will almost reach this amount one day after death.
From the point of view of bacterial reproduction and histamine growth rate, if the dead crab is stored at room temperature for more than three hours or refrigerated for more than one day, it can be considered to give up eating.
Again, only if you know when it died. If the hairy crabs on the food stall are dead, I suggest not buying them. When I woke up, I found that I was alive last night and now I am dead. If you ask me, I'd better not eat them either.
Moreover, everyone has different sensitivity to these harmful substances, and only eating a little bit may cause adverse reactions. Dead hairy crabs are still not recommended for everyone.
How long can cooked crabs be kept?
People say I steamed the crabs alive, but I actually steamed a lot. Can cooked crabs be kept longer?
Actually, it's not just crabs. Usually, many leftovers can't be kept for a long time. Nutrients such as water and protein can still provide good breeding conditions for bacteria.
It is also possible if it is stored at room temperature for less than 4 hours, or refrigerated for less than 1 day, and reheated before eating.
But it won't be longer than that.
As a reminder, crab shells are thick and difficult to heat thoroughly, so you can steam them for a while, or take them out and heat them separately.
Is it okay to freeze live crabs?
Besides buying fresh crabs, what else can be done to preserve crabs safely in advance?
You can consider putting the crab directly into the freezer when it is alive, and then taking the amount you want to eat every time you want to eat.
Relevant experiments show that even under the conditions of ordinary families, there is basically no problem in freezing for two or three weeks.
Freezing live crabs in the refrigerator at home is different from buying frozen crabs directly. Other self-frozen foods and quick-frozen products will have the same problem.
The temperature of frozen food in household refrigerators gradually decreases, and water will gradually form small ice crystals in the microstructure, which may pierce the original cell structure. Specifically, the quality of meat may be affected.
The quick-freezing process will not destroy the original cells, and the quality will be higher.
Second, don't eat these four parts when eating crabs.
Jiang Hong, a nutritionist in the Nutrition Department of Hangzhou First People's Hospital affiliated to Zhejiang University School of Medicine, once pointed out that when eating crabs, the stomach, intestines, heart and gills of crabs must be removed. These parts are organs for crab to filter and metabolize waste, which have no edible value and contain a lot of bacteria and parasites, which are easy to cause food poisoning.
Crab stomach, commonly known as "crab urine bag", is a triangular bone bag with sludge in the center of the front edge of its back shell. Crab intestine is a black line from crab stomach to crab navel; Crab heart is commonly known as "hexagonal plate"; Crab cheeks are commonly known as "crab eyebrows", that is, two rows of things as soft as eyebrows that grow in the abdomen of crabs.
Third, steam the crabs for 20 minutes after the water boils.
Boiling crabs with water will make the delicious and nutritious components in crabs spread into the water, thus destroying the delicious flavor and nutritional value of crabs. Steaming is a good way to make crabs, because steaming is more advanced than boiling, which not only cooks quickly, but also kills microorganisms and parasites on crabs. Steamed crabs can also maintain the integrity of the crab body, make its color ruddy and bright, and reduce the pollution of crab meat by the gastrointestinal contents of crabs.
But it should be noted that crabs should be washed before steaming. Hold both sides of the big cover at the root of the crab's two rows of legs with your hands (no matter how you move this place, the crab can't hold your hands), and then brush all the places you can with your toothbrush. When steaming crabs, pay attention to steaming for at least 20 minutes after boiling, and it is possible to kill germs after cooking.
Fourth, eating crabs can be matched with warm stomach food.
Xu Huichao, from the Nutrition Department of the Affiliated Hospital of Jining Medical College, once pointed out that eating crabs should be accompanied by something that warms the stomach, such as Jiang Mo, vinegar and yellow wine, which is related to the fact that Chinese medicine believes that crabs are cold.
In China, people have thought that yellow rice wine and crabs are a perfect match since ancient times. Although the crab is delicious, it is cold, and eating too much can easily hurt the stomach. Yellow rice wine has the effect of promoting blood circulation and warming the stomach, so it has always been considered as the best choice to remove cold when eating crabs.
Although crabs are delicious, don't eat too much.
The cholesterol content of crabs is very high, especially crab roe, so crabs should be eaten in moderation, not too much, otherwise it will easily lead to high cholesterol. In addition, crabs are cool foods, so people with deficiency of spleen and stomach are not suitable for excessive consumption.
Sixth, picking crabs mainly depends on five aspects.
When choosing crabs, you should start from the following five aspects:
A look at the color, fresh crabs "green back and white belly, golden claws and yellow hair", the back shell is turquoise and shiny, the abdomen is white and full, and it can spit bubbles constantly.
Secondly, depending on the individual, the crab should choose the big, old and healthy one, so that the crab meat is more compact.
Third, look at the navel, the navel should protrude outward. Whether it is a male crab or a female crab, such crabs are generally full of fat.
Fourth, look at crab hair. Crabs with hairy feet and hard legs are the fattest.
Look at the action, fresh crabs have strong clamping force, complete crab legs, fast and powerful crawling, and agile and positive movements. ④
Seven or seven people should not eat crabs.
Patients with hepatitis should not eat crabs.
Hepatitis patients are prone to dyspepsia, abdominal distension, vomiting and other symptoms due to gastric mucosal edema, abnormal bile secretion and decreased digestive function, while crab meat is rich in protein, which is difficult to digest and absorb.
People with cardiovascular diseases should avoid eating crabs.
Crabs contain high cholesterol, with 235 mg of cholesterol per100g of crab meat and 460 mg of cholesterol per100g of crab roe. Patients with coronary heart disease, arteriosclerosis, hypertension and hyperlipidemia eat foods with high cholesterol content, which will lead to the increase of cholesterol and aggravate the development of cardiovascular diseases.
People who have a cold and fever should not eat crabs.
Cold diet should be light, high-protein crabs are not easy to digest and absorb, and it is easy to make a cold difficult to heal or aggravate the condition after eating.
Anyone with spleen and stomach deficiency and cold should not eat crabs or eat less.
Crabs are cold and easy to cause abdominal pain, diarrhea or indigestion after eating. Patients with chronic gastritis and gastric and duodenal ulcers had better not eat crabs, because it is easy to relapse or aggravate the old diseases after eating them.
People with allergies should avoid eating crabs.
After such people eat crabs, specific crab proteins enter the body through the intestinal wall with increased permeability, causing allergic reactions and a large amount of histamine, causing gastrointestinal smooth muscle spasm and vascular edema, leading to nausea, vomiting, abdominal pain and diarrhea; Some can also cause urticaria or asthma. In addition, people suffering from dermatoses such as dermatitis, eczema and tinea should also be careful to eat, because eating crabs will worsen their condition.
People with biliary tract diseases should not eat crabs.
Such as cholecystitis and cholelithiasis. The formation of cholecystitis and gallstones is related to excessive cholesterol and metabolic disorder in the body. Eating crabs is easy to make the disease relapse or aggravate.
Pregnant women should eat less or not eat crabs.
Chinese medicine believes that crabs are cold and have the function of promoting blood circulation and removing blood stasis, so they are not good for pregnant women.
Eight, the first person to eat crabs
In China, crabs are not only a delicacy, but also a culture. People in China have been eating crabs for thousands of years.
Mr. Lu Xun's famous saying that "the first person to eat crabs is a warrior" has been passed down to this day, so who was the first person to eat crabs?
There is a legend in Suzhou: According to legend, in the Dayu era, river crabs were called "human-catching insects". During Dayu's flood control, a overseer named Plo dug a deep ditch and put hot water in the station to prevent the invasion of "human traps". As a result, the scalded "human trap" had a unique fragrance, and Plough picked it up and tasted it, which was delicious. Since then, "arresting people" has become a delicious food on earth. Because the PLO suppressed this "human trap", it was named "Crab".
In fact, China has a history of eating crabs for more than 6,000 years. In the Yangtze River Delta, archaeologists have found that there are a lot of crab shells in the waste eaten by ancestors, which shows that people in China have a long history of eating crabs.
In the history of China, how many literati fell in front of the "heartless son", and they all praised the delicacy of crabs from all angles. In the Song Dynasty, Xu Sidao, commander-in-chief of Wujiang, wrote a poem entitled "Don't eat crabs until you see their true colors", which became a famous sentence in crab culture and spread widely. Li Bai, a poet in the Tang Dynasty, once praised: "Crab claws are golden liquid, and bad mountains are Penglai. And you must drink and get drunk on the platform next to the moon. " However, among the poems about crabs in past dynasties, the most famous one is Pi Rixiu's poem about crabs, which says, "You were famous before you swam in the sea, but you had bones, and you were born from the flesh. Mo Dao is not afraid of thunder, and the sea dragon king is also crazy. " Just a few numbers, the crab's rampage and fearless temperament are vividly on the paper. "
Nine, the hands and feet are not enough? Collection tool
In the Ming and Qing Dynasties, it was a cultural enjoyment for literati to taste crabs. Everyone has a special set of tools when enjoying chrysanthemums, reciting poems and eating crabs. Suzhou, Shanghai and Hangzhou were once commonly known as "Eight Crabs". "Eight pieces of crab" include crab pier, crab hammer, crab axe, crab tag, crab scissors, crab pliers, crab knife and crab spoon, which have many functions such as cushion, knock, split, fork, shear, clamp, pick and hold.
First, put the crab on a small square table (crab pier), cut off two big paws and eight feet one by one with crab scissors, gently tap around the crab shell with a hammer, then split the back shell and navel with a crab axe, then pick up the crab knife, crab tongs, crab sticks, crab hammers and crab spoons, or pick or clamp or fork or knock or hold them, and take out golden and shiny crab paste or creamy and tender crab meat. A tool is used in turn, and a function is played alternately, as if playing a cadence food song.
From the Ming Dynasty to the early years of the Republic of China, on this basis, 10 and 12 crabs appeared. After that, as many as 64 sets of tools for eating crabs appeared at most.
I want to remind parents that although crab meat is beautiful, don't give too much to their children, and don't give them dead crabs to save money.
Part of the material in this article is synthesized from nutritionist Gu Zhongyi, Health Times, Shandong TV Life Channel, Healthy Hangzhou, China Science Expo, etc.