The "Sour Tangzi" incident triggered a panic on the Internet. How terrible is the "back pot" poison?
The knowledge points about aflatoxin are here
Our reporter Ma Aiping
On October 19, the National Health Commission’s WeChat public account "Healthy China" announced that on October 5, a food poisoning incident occurred in Jidong County, Heilongjiang Province, caused by eating sour soup at a family dinner. All 9 people died after eating it. .
It has been found that the disease-causing food is sour soup contaminated by pathogenic bacteria.
At first, the cause of death was judged to be aflatoxin poisoning, but this result was questioned by many experts.
The truth of the matter became clear, but aflatoxin, which was almost "back-to-back," has recently caused panic on the Internet, and some rumors related to this have been continuously forwarded.
In the circle of friends, similar to Pu'er tea containing aflatoxin and yellowing of rice are because of the growth of Aspergillus flavus and other "old rumors" that have begun to make waves.
So, what are Aspergillus flavus and aflatoxin?
How harmful are they?
What foods will they contaminate?
What should I do if I accidentally eat it?
In this regard, a reporter from Science and Technology Daily interviewed relevant experts.
How harmful is it? 1 mg of aflatoxin can induce cancer
"Aspergillus flavus is a kind of Aspergillus flavus, usually showing yellow or yellow-green visible to the naked eye. It is most suitable for survival in the environment of 30 degrees Celsius to 38 degrees Celsius and pH value of 5.5. It is easy to grow in soil, organic matter, and grains. ." Luo Yunbo, a professor at the School of Food Science and Nutritional Engineering of China Agricultural University, said in an interview with a reporter from Science and Technology Daily.
Luo Yunbo explained that aflatoxin refers to secondary metabolites produced by toxin-producing strains such as Aspergillus flavus and Aspergillus parasitic within the genus Aspergillus, which have strong carcinogenicity.
Sun Yi, a professor at the School of Life Sciences of Shanxi Agricultural University (Shanxi Academy of Agricultural Sciences) and a member of the 8th Science and Technology Committee of the Ministry of Agriculture, told the reporter of Science and Technology Daily that in 1993, aflatoxin was designated by the World Health Organization (WHO) Cancer Research Institute as A class of naturally occurring carcinogens are highly toxic and highly toxic substances.
"The toxicity of aflatoxin is 68 times that of arsenic and 10 times that of potassium cyanide. 1 mg of aflatoxin can induce cancer, and 20 mg can kill people." said Liu Gang, a researcher at the Institute of Microbiology, Chinese Academy of Sciences. .
"After aflatoxin enters the human body, it can be absorbed by the liver, metabolized and transformed by cytochrome enzymes, and induced mutations in tumor suppressor genes, thereby causing cancer." Luo Yunbo pointed out.
Aflatoxin is not a compound, but a general term for a group of compounds with similar chemical structures. So far, 20 aflatoxins and their derivatives have been isolated, including toxins such as B1, B2, G1, G2, and M1. And poison alcohol.
Luo Yunbo said that among the natural foods, aflatoxin B1 is the most common and the most harmful. It is mostly found in peanuts and their products, nuts and dried fruits.
The metabolite of aflatoxin B1 is aflatoxin M1, which is mostly found in milk and dairy products.
What substances will it contaminate? Most "favorite" foods like peanuts and rice
"Aspergillus flavus mainly pollutes grain, oil and its products. It most'likes' foods such as peanuts, rice, and corn." Sun Yi said.
Luo Yunbo said that aflatoxin is also more common in animal foods, such as liver, salted fish, milk and dairy products.
In addition, traces of aflatoxin have also been found in spices, nuts, dried fruits, condiments, and fermented foods.
In daily life, Aspergillus flavus tends to "hide" in refrigerators that have not been thoroughly cleaned for a long time and in humid, dark, and high-temperature places.
"But it should be noted that even if Aspergillus flavus grows, it may not produce toxins, and not all Aspergillus flavus strains can produce toxins." Luo Yunbo said.
In fact, only a few molds such as Aspergillus flavus and Aspergillus parasiticus can produce aflatoxin.
"Some foods in daily life, such as fermented bean curd and tempeh, the mold they produce is Mucor, and Mucor does not produce aflatoxin." Liu Gang said.
"As long as household kitchen utensils and tableware are kept clean and dry, so that mold has no chance to grow, they will not produce and accumulate aflatoxin and other fungal and bacterial toxins. Therefore, maintain good hygiene practices and ensure that the raw materials are safe and pollution-free. The most important means to prevent the breeding of Aspergillus flavus." Sun Yi said.
What should I do if I accidentally eat a small amount? It can be discharged by inducing vomiting and drinking more water
So, how do we identify and remove aflatoxin?
"Take the grains that are prone to aflatoxin as an example. In daily life, before we eat such foods, we need to identify them, and identify whether they contain aflatoxin according to whether they are moldy, discolored, or deteriorated. Aflatoxin is very heat-resistant, and household cooking temperature generally cannot destroy its structure. Only through long-term high-temperature heating can most of it be inactivated." Luo Yunbo said.
However, Luo Yunbo pointed out that ultraviolet rays and microwaves can destroy the structure of aflatoxin, so exposure or microwave heating can help to remove aflatoxin in food and reduce its toxicity.
According to the current national food safety standards, the maximum content of aflatoxin in common foods shall not exceed 20 μg/kg. For example, the limit value in corn, corn flour and corn products is 20 μg/kg, and in rice, brown rice, and rice. The limit value of is 10 μg/kg, and the limit value in wheat, barley, wheat flour, and oatmeal is 5.0 μg/kg.
According to data from the World Health Organization, accidental consumption of food containing aflatoxin with a concentration of more than 1 mg/kg may cause aflatoxin poisoning.
"Eating food that meets national standards will not cause acute aflatoxin poisoning. If you accidentally swallow it and you have symptoms of poisoning, you need to treat it according to the clinical situation. If a small amount of accidental ingestion does not cause obvious clinical The reaction can be eliminated from the body as soon as possible by inducing vomiting, drinking more water, and drinking milk appropriately. If the symptoms of poisoning are more obvious, you must be sent to a doctor in time to prevent the condition from getting worse." Luo Yunbo said.