Cai Honglin: nutritionist of Union Medical College Hospital, standing committee member of nutritionist professional committee of Chinese Medical Doctor Association, director of Hubei Nutrition Society, and standing director of Hubei Medicinal Diet Research Association.
Crayfish contains heavy metals? Citizens need not worry.
It is said that crayfish are used to absorb heavy metals in wastewater and soil abroad, not for eating. It is also circulated on the Internet that some crayfish are fished out of the gutter and contain a lot of heavy metals. Dr. Cai Honglin of Union Medical College Hospital thinks there is no direct evidence. Crayfish came to China from abroad, and definitely not for this purpose after entering China. The original crayfish mainly came from the wild, and some may come from the gutter, but this is also a small part. The main pollution sources in the sewer are some rotten animals and plants, parasites and some harmful bacteria, not the harm of heavy metals. Heavy metals mainly come from industrial wastewater, so there is no need to worry so much about heavy metals.
Most crayfish are farmed, so the hygiene of water quality is guaranteed, and there is no need to worry about hygiene problems. Dr. Cai Honglin reminded: "It is best not to eat shrimp in the gutter, it will have some toxins harmful to the body."
Crayfish is nutritious, low in fat and high in protein, but don't eat too much.
The protein content of crayfish is 16, and the fat is only 1.4%, which accords with the characteristics of high protein and low fat. Its energy is not very high, 100 grams is 77 kcal. Besides protein, he also contains vitamins such as nicotinic acid, thiamine and riboflavin, as well as elements beneficial to human health such as iron and zinc. The iron content of crayfish is very high, reaching 14.5%, which is the highest among all shrimp species. For example, the iron content of river shrimp and Neopenaeus monodon is only a few percent, while the iron content of crayfish reaches 14.5%, which is twice as high as that of other species. It has a high iron content and is a very good choice for China people.
Only 14% of crayfish was eaten, and the remaining 86% was discarded. According to the recommendation of the Nutrition Society of China, a day is 50 to 100g fish, which is about 350 to 700g shrimp. If you eat too much shrimp, you will eat less other high-quality protein food, so you'd better not eat this for two meals. It is best not to eat crayfish more than once or twice in another week.
People who are allergic to crayfish should eat as little as possible.
Some netizens are allergic to eating crayfish Changfeng Tuan. Allergies vary from person to person. Someone is allergic to lobster, which means he is allergic, and crayfish is his allergic source. In addition, in fact, in addition to eating crayfish itself, crayfish may add other substances during processing, and other chemicals added may also be allergens, so the allergens may be crayfish or some kind of seasoning. If people are allergic to crayfish, it is best not to eat them.
Experts teach you to tell the difference between dead shrimp and live shrimp.
When people eat shrimp, they often encounter shrimp that will kill them. Dead shrimp is harmful to human health. On the one hand, because shrimp is rich in protein, after its death, bacteria will multiply and decompose and destroy protein. First of all, the taste is not very good, and a large number of bacteria will lead to food poisoning. In addition, the process of bacterial reproduction will produce a lot of toxins, which will also poison us. Poisoning can lead to acute gastrointestinal reaction, abdominal pain, abdominal distension and diarrhea. In addition, after shrimp died, protein decomposed amino acids, in which histamine acid was decomposed into histamine. The longer the shrimp dies, the higher the histamine content, and when the histamine content exceeds a certain concentration, the human body will also feel uncomfortable. This reaction is a bit like food allergy, but also skin redness, or urticaria, or asthma. The symptoms are obvious, mainly because the face and chest are red and not good. If the concentration is high, it will also cause cardiovascular diseases.
How to distinguish live shrimp from dead shrimp? First look at the appearance. Look at the color first. Live shrimps are bright, red, shiny and bright. The color of dead shrimp is black, and the gloss is much worse; In addition, it depends on his integrity, whether his arms and legs are there, and if he dies, he may be missing his arms and legs. Live shrimp must be very sound and all structures are very complete; Then there is the smell of shrimp. Dead shrimp must have a strange taste, which is different from that of live shrimp. The third is to taste the taste. Obviously, the meat quality of live shrimp is elastic, chewy and delicious. The meat of dead shrimp is a bit meaty, not chewy, a bit like carrion, like bean curd residue, and the taste can be clearly distinguished.
Dr. Cai Honglin suggested that if you feel that the taste is wrong once you eat it, spit it out quickly, and it is best not to swallow it, which may lead to food poisoning. In fact, there is another way, that is, look at the tail of shrimp. If the tail is curly, it may be live shrimp (here refers to cooked shrimp); If the tail is straight, it may be dead shrimp. This is also related to muscle elasticity. When it is elastic, it will bend. If it has no elasticity, it is it. As can be seen from the above three parts.
Steamed crayfish is the healthiest barbecue crayfish, and it is best not to eat it.
Dr. Cai believes that steamed shrimp is the healthiest and grilled shrimp is the most unhealthy. Stir-fried braised shrimp depends on what you do. If you use the right amount of oil and seasoning, it is not unhealthy. I'm afraid you use too much oil and pungent spices when cooking. It is not very good from the health point of view to advocate a light and alkali-free diet now.
Grilled shrimp is the worst way. First, the shrimp body is in direct contact with fire, and the temperature is relatively high. At high temperature, it is easy to decompose protein and produce some substances harmful to the body; These substances may have carcinogenic effects on people. In addition, charcoal fire may also contain some toxins, which will pollute shrimp and be harmful to human body. At the same time, some things for barbecue may be prepared in advance, so it is not easy for you to tell whether the shrimp is alive or dead. In the process of barbecue, too many strong condiments will be added to cover up this unpleasant smell, which makes it difficult to distinguish. There are more opportunities for grilled shrimp to be shoddy and shoddy. It is recommended not to eat grilled shrimp.
Don't mix crayfish with persimmon strong tea and beer, which may cause stones.
Crayfish is a high-protein food. The general principle is that foods with more tannins should not be eaten together. Such as persimmon, strong tea, pomegranate, grape, etc. These tannins will combine with protein to form insoluble compounds, which are not easy to digest and absorb in the gastrointestinal tract, and become jaundice, leading to gastrointestinal discomfort. Eating too much can lead to stones and even more serious consequences.
In addition, because shrimp is warm, don't drink a lot of cold beer when eating shrimp, especially people with sensitive stomach may have diarrhea. If you drink some white wine, it is also warm, and your stomach discomfort will be lighter.
Consider this problem from the perspective of a balanced diet, because crayfish is an animal food. It is recommended to eat some fresh vegetables and fruits at the same time, and also eat some staple foods to balance the diet, which can also help the body absorb nutrients.
Experts summarize the precautions for eating crayfish.
First, to ensure the freshness of raw materials, raw materials must come from clear water culture. To see if it is clean water or sewage, you can turn the shrimp upside down to see if it is clean, polluted and smelly.
Second, in the process of eating, if possible, it is best to do it yourself. The first brush is cleaner. Second, the wing treatment may be better. Third, you can't use too much oil and spices. You can even make steamed shrimp. If you eat out, you'd better choose a restaurant with a good reputation, or a bigger one. If it's a street stall or a very cheap shop, it's a bit unreliable, afraid that the raw materials are not fresh, and there are some problems with the ingredients made.
Third, when we eat crayfish, some people should be cautious. For example, people with yin deficiency and excessive fire, people who get angry, people who often love constipation, allergic rhinitis or allergic dermatitis, and people with obvious skin diseases may get worse if they eat shrimp at this time. If you really want to eat, wait until the symptoms in your body are slightly relieved.