Eating crayfish that has been dead for more than 2 hours is easy to be poisoned, can frozen crayfish be eaten?

Recently, #Eating dead crayfish more than 2 hours is easy to be poisoned # ranked 3rd on the Weibo hot search list, whether quick-frozen crayfish are included, how crayfish should be eaten, etc. has become a hot topic of discussion among netizens.

Experts said that it is not recommended to eat crayfish that die for more than 2 hours, mainly because the decay and deterioration of dead shrimp under the summer room temperature is accelerated, and it is easy to be contaminated by pathogens and breed toxic substances. For quick-frozen crayfish, etc., although their form has died, they are processed and frozen in a fresh state of crayfish and can be eaten. When cooking crayfish, consumers should pay attention to cooking and cooking thoroughly.

Crayfish that have been dead for more than 2 hours are susceptible to spoilage

On July 3, Jiangsu News Weibo reported that crayfish belong to high-protein food, hot weather in summer, under the decomposition of bacteria, high-protein food is very easy to spoil, spoil, and crayfish contain a lot of histidine, when the crayfish dies, these histidine will soon become toxic substances, people are easy to cause food poisoning after eating. Crayfish are eaten more than 2 hours after death, which is easy to cause poisoning and is not recommended to eat. That night, the topic of #crayfish that died for more than 2 hours was easily poisoned was hotly discussed and rose to the third place in Weibo hot search.

Tang Jianqing, chief expert of the modern agricultural industry technology system of Jiangsu Province, told the Beijing News reporter that in fact, compared with freshwater shrimp, freshwater crabs are more likely to produce toxic substances due to histidine during death, which poisons eaters. Therefore, crayfish can be eaten just after they die, but river crabs and the like cannot be eaten once they are dead. It is not recommended to eat crayfish after a few hours of death, mainly after the crayfish have spoiled, the spoiled substance may produce other toxins, creating food safety risks.

For why the time when crayfish are inedible is defined 2 hours after death, Zhu Yi, associate professor of the College of Food Science and Nutritional Engineering of China Agricultural University, analyzed to the Beijing News reporter that the relevant report may refer to the "Five Points of Food Safety" issued by the World Health Organization. The main points point out that at room temperature, cooked food should not be stored for more than 2 hours; cooked food and perishable foods should be refrigerated and stored (below 5 ° C); cooked food should be kept above 60 ° C before eating. The longer it is left at room temperature, the greater the risk of microbial growth and reproduction. From a safety perspective, food should be eaten immediately after it comes out of the pan.

Dead shrimp is risky, so can the frozen lobsters and crayfish prepared dishes that you buy every day still cook with confidence? Ruan Quang Feng, director of the Science and Technology Communication Department of the Food and Health Information Exchange Center of Kexin, said that although the longer aquatic products die, the more likely they are to be contaminated by germs and increase the risk of breeding toxins. "But this 'death' also depends on how it dies, and the crayfish that have died frozen after formal processing and the dead shrimp caught from the pool are two concepts."

Zhu Yi also pointed out that the pre-packaged crayfish sold on the market are usually frozen after cooking fresh lobsters, as long as the cold chain transport storage process is guaranteed to be low, and when eating, it is reheated to boiling, and there is no need to worry about food safety risks. "If consumers are still not at ease, they can choose branded goods instead of bulk products." When buying crayfish, consumers can also identify the freshness of the shrimp head by whether it is easy to break, and the thawed crayfish can rely on observing whether the meat is soft and the smell is unpleasant. At the same time, the summer high temperature and high humidity, the rapid reproduction rate of pathogenic microorganisms, the crayfish are easy to spoil and deteriorate, consumers should remember to refrigerate the processed crayfish in time.

The crayfish should be cooked thoroughly

In addition to not recommending eating crayfish 2 hours after death, the report also points out that at temperatures above 70 ° C, crayfish cooking for 10 minutes can kill the parasite, and at a temperature of 100 ° C, the time is shorter. However, when cooking crayfish, not all parts of the crayfish can be kept at 100 ° C, so it is recommended that consumers cook for more than 10 minutes before eating.

In Nguyen Quang Feng's view, from the perspective of safety and cooking, the cooking of crayfish does not necessarily have to wait for 10 minutes to open the pot. Although the crayfish with shells, but in the case of the central temperature reached, more than ten seconds to two or three minutes can kill the parasite, cooking 10 minutes may be a little long, according to the actual situation, there is no need to pinch the second, "but many people cook longer can also make the crayfish taste more flavorful and more delicious." ”

Zhu Yi also believes that on a daily basis, cooking crayfish may take less than 10 minutes. However, the relevant reports on the 10-minute recommendation may take into account various factors, such as whether the crayfish has been thawed when cooking, whether it is shelled, high or low fire, etc. The real meaning of this advice may be that everyone must cook the crayfish thoroughly, rather than saying that it is stuck in 10 minutes.

The Beijing News reporter noted that for the relationship between cooking time and firepower, as well as the cooking temperature setting of 70 ° C, the World Health Organization pointed out in the "Five Points of Food Safety" that the correct cooking method and the appropriate temperature can kill almost all harmful microorganisms, and the temperature of cooking food reaches 70 ° C to help ensure food safety. Therefore, when processing meat, poultry, eggs, seafood and other foods, it is necessary to cook and burn thoroughly, especially roast meat, meat filling, large pieces of meat and whole chicken. If a low heat is used, due to the low temperature, it is necessary to extend the time, that is, "low heat and slow simmering".

Beijing News reporter Wang Sijiao Picture source Wang Sijiao

Edited by Zhu Fenglan Proofreader Li Shihui