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How to tell if the crabs eaten in restaurants are fresh?
1, a method for judging the freshness of seafood

A method for quickly identifying fresh crabs:

1. Check the connection between limbs and body.

The feet of fresh crabs are closely connected with the body, so the feet will not droop when lifting crabs. The stale crab will obviously relax at the rotatable place where the limbs meet the body. When you lift the crab by hand, you can see that the limbs (feet) sag downward.

2. Look at the "stomach print" above the navel.

Crabs mostly feed on humus. After a period of death, the stale contents of the crab's stomach will rot, and black marks will appear on the crab's belly and navel.

3. Is the crab "yellow" solidified?

The substance called "crab yellow" in crabs is where many internal organs and reproductive organs are located. When the crab is in the zombie stage, the "crab yellow" solidifies. Stale crabs are semi-fluid. The crab body becomes thinner when it deteriorates, and it can feel the flow in the shell when it turns over.

Look at the gills

Fresh crabs have clean gills, clear gills, white or slightly yellowish brown. The gill filaments of stale crabs began to rot and adhere, but it was not observed until the shell was peeled off.

Is there a difference between a male crab and a female crab?

It tastes different.

Crabs are orange-red, and hard ones are crab yellow. Crabs with crab roe are female crabs, and crab roe is the ovary and egg cells of crabs. Generally, around September of the lunar calendar, the gonad of the female crab is mature and the crab meat is the most plump. Male crabs can't.

White sticky crab paste is crab paste, crabs with crab paste are male crabs, and crab paste is the accessory gonad of crabs. Generally, after October of the lunar calendar, male crabs have mature gonads and the most plump crab meat. But the mother crab didn't.

There are so many ways to tell the freshness of crabs. Pay attention to the difference between male and female crabs.

First, identify the freshness of cooked fish. As far as fish are concerned, fresh fish look at their pectoral fins. After the really fresh live fish is cooked, the pectoral fins must stand up! Gently poking the pectoral fin with chopsticks still feels elastic, while the pectoral fin always clings to the abdomen after the dead fish is cooked.

Second, identify the freshness of cooked shrimp and crab food. Look at the tail wings of shrimp. The so-called "fresh shrimp has a tail." After the fresh shrimp is cooked, the tail muscles contract strongly and the tail must be fanned out. If the shrimp hair is black, the cooked shrimp tail fins are still tightly stacked together, and most of them are dead shrimps before cooking. As for crabs, it mainly depends on the taste of meat. If the meat tastes elastic and sweet, it will be live seafood before cooking. If the meat is firewood, it will mostly be dead crabs.

Third, identify the freshness of shellfish. Fresh shellfish depends on the opening of shellfish. If the shell has been opened, smell it to see if there is any "soup" flowing out. If the cooked shellfish smells rotten, the meat is not tight, and there are a lot of sand and odor, it must be cooked after death.

2. Precautions for eating seafood

First, seafood is undercooked and contains bacteria.

The bacteria in seafood are mainly Vibrio parahaemolyticus, which has strong heat resistance and can only be killed above 80℃. In addition to bacteria brought by water, there may be parasitic eggs in seafood, as well as bacterial and viral pollution caused by processing.

Reminder: Generally speaking, boiling in boiling water for 4-5 minutes is considered as complete sterilization. Therefore, we must be careful when eating unheated seafood such as "drunken crab", "raw sea urchin" and "sauce-fried seafood", and we must ensure the freshness and hygiene of fish when eating sashimi.

Second, there are many toxins in dead shellfish.

The bacteria carrying capacity of shellfish itself is relatively high, and protein decomposes quickly. Once it dies, it will breed a large number of bacteria and produce toxins, and the unsaturated fatty acids contained in it are also prone to oxidative rancidity. Stale shellfish will also produce more amines and free radicals, which pose a threat to human health.

Reminder: Live shellfish should not be stored at home for too long after purchase. Cook them as soon as possible. People with allergies should pay special attention, because sometimes allergic reactions are not caused by seafood itself, but by substances in the process of protein decomposition of seafood.

Third, eating seafood and beer together can induce gout.

If you eat a lot of seafood and drink beer at the same time, it will accelerate the formation of uric acid in the body. Excessive uric acid can be deposited in joints or soft tissues, leading to inflammation of joints and soft tissues. When gout attacks, not only the affected joints are red, swollen, hot and painful, but even the whole body has a high fever, which looks like sepsis. Over time, the affected joints are gradually destroyed, and even lead to kidney calculi and uremia.

Reminder: Therefore, when eating a lot of seafood, don't drink beer, otherwise it will have a bad influence on your health.

Fourth, eating seafood and fruit together will cause abdominal pain.

Fish, shrimp and algae in seafood are rich in protein and calcium. If they are eaten together with fruits containing tannic acid, such as grapes, pomegranate, hawthorn and persimmon, it will not only reduce the nutritional value of protein, but also easily combine calcium and tannic acid in seafood into indigestible substances. When these substances irritate the stomach and intestines, they will cause human discomfort, ranging from gastrointestinal bleeding to vomiting, dizziness, nausea, abdominal pain and diarrhea.

Reminder: Therefore, it is not advisable to eat fruit immediately after eating seafood. It is best to eat at intervals of more than 2 hours. Many people use antibiotics as soon as diarrhea occurs, which is not only useless for prevention and treatment, but also further damages the immune function of the human body and makes the damaged body weaker. Therefore, medication is generally not recommended except for patients with severe abdominal pain who can take medication under the guidance of a doctor. To this end, experts remind everyone that the key to preventing non-bacterial lovely diarrhea is to control diet and find out the causes of improper diet and gastrointestinal absorption disorder.

5. Drink tea after eating seafood and long stones.

The reason why you should not drink tea after eating seafood is similar to the reason why you should not eat fruit. Because tea also contains tannic acid, it can also form insoluble calcium with calcium in seafood. Eating seafood before or after eating seafood will increase the chance of combining calcium with tannic acid.

Reminder: Therefore, it is best not to drink tea when eating seafood. Similarly, an interval of more than 2 hours is also the best.

Six, chilled shrimp should not be eaten for free.

Any seafood can only be made into steamed and cooked dishes in a highly fresh state. Aquatic seafood, unlike meat, contains many low-temperature resistant bacteria, and protein decomposes very quickly. If it is kept in the refrigerator for a long time, the bacterial content of shrimp will increase, and protein will be partially denatured, producing amine substances, which will not reach the taste, flavor and safety of live shrimp in any case, and it is certainly not suitable for boiling.

Reminder: However, chilled shrimp can be fried or fried at high temperature, which can also present delicious taste.

Seven, seafood vitamin C and food poisoning.

All kinds of seafood, such as shrimp, crab, clam and oyster, contain the chemical element arsenic. Generally, the content is very small, but the increasingly serious environmental pollution may make the arsenic content in these animals reach a higher level. The valence state of arsenic contained in shrimp is pentavalent. Under normal circumstances, pentavalent arsenic is harmless to human body. Theoretically, high doses of vitamin C (more than 500mg of vitamin at a time) and pentavalent arsenic will be converted into toxic trivalent arsenic (arsenic) through complex chemical reactions, and trivalent arsenic can cause human poisoning when it reaches a certain dose.

Reminder: Eat 50 medium-sized apples or 30 pears or 10 oranges or eat more than 3 kilograms of green leafy vegetables at one time, and then take a large dose of vitamin C. If you cook by heating, the vitamin C in food will be greatly reduced. Therefore, it is not dangerous to eat fruits or vegetables while eating seafood, as long as it does not exceed the above amount. Metal elements are easy to deposit on the head of seafood. Try not to eat shrimp heads and fish heads.

Eight, arthritis patients should avoid eating more seafood.

Sea cucumber, marine fish, kelp, laver and other seafood contain more uric acid, which is absorbed by the human body and forms uric acid crystals in joints, aggravating arthritis symptoms.