Attention, fans of "noodle slurping"! This type of food poisoning is more common in summer and can be fatal!

Fried rice noodles, Guilin rice noodles, Changde rice noodles, Guangdong rice noodle rolls, Nanning Laoyou rice noodles, Liuzhou snail rice noodles, Guizhou mutton rice noodles, Huaxi rice noodles, Nanchang mixed noodles, Xinjiang fried rice noodles, Shaanxi cold noodles... For noodle lovers, just reading this series of names may make their mouths water. If you slurp a handful of salty, fragrant and hot noodles into your mouth, it is a rare and delicious enjoyment in the world.

However, the hot summer has arrived, and many parts of the country are experiencing hot and humid weather. Students who love rice noodles should be careful: eating rice noodles in this kind of weather may cause poisoning!

Can you get poisoned by eating cold noodles or rice noodles?

Recently, a hot search about "someone died from poisoning after eating cold noodles, and the sale of cold noodles was banned in a place in Henan" made people stay away from eating cold noodles.

According to the news, two women in Yongcheng City, Henan Province, were poisoned after eating cold noodles, resulting in one death and one injury. At present, all cold noodles shops in Yongcheng City have been closed down and are temporarily prohibited from selling cold noodles. There are two versions of the cause of the poisoning: one version says that excessive borax was added to the cold noodles; the other version says that the cold noodles were contaminated by bacteria and deteriorated, breeding fumonisin toxins and causing poisoning.

In fact, similar incidents occur almost every year.

According to data provided by the Guangxi Centers for Disease Control, in the 10 years from 1996 to 2005, there were 11 food poisoning incidents caused by eating vermicelli in eight counties including Bama and Lingyun in the two cities of Hechi and Baise in Guangxi alone. A total of 77 people were poisoned, including 50 deaths!

In July 2020, a food poisoning case occurred in a rice noodle shop in Huilai, Guangdong. After eating rice noodles (kway teow), 11 customers suffered varying degrees of vomiting and diarrhea. One of them died after full rescue and treatment, two were in critical condition, two were in stable condition, and six were under observation at home because of mild symptoms.

Why do these wet rice noodles or cold noodles produce "fumonisin toxin"? Where does the toxin come from? Can you still happily slurp noodles afterwards?

Today, let’s take a closer look at this rice noodle killer - aflatoxin.

What is fumonisin?

In 1977, fumonisin was first found in spoiled fermented rice flour in Northeast my country. It is a food-borne pathogen. Since the mid-20th century, more than 9,000 people have been reported to have been poisoned by fumonisin in China.

Aflatoxin is a bacterial toxin with a long-chain fatty acid structure. It is produced by Burkholderia gladiolus (Pseudomonas cerebrovenenans subspecies) that can cause food poisoning or even death. 26℃~28℃ is the optimal temperature for its toxin production.

Food contaminated by Burkholderia gladioli produces fumonisin, which can cause poisoning in humans. Fumonisin is highly toxic and often affects solid organs such as the liver, kidneys, brain, heart, and lungs. In mild cases, it can cause abdominal pain, vomiting, diarrhea, fatigue, and irritability in the victim. In severe cases, it can quickly cause liver and kidney damage and lead to multiple organ failure and even death.

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The key is that the food contaminated by it is colorless and tasteless, making it difficult to identify. Fumaric acid is very hardy. Not only is it not afraid of cooking, it is also extremely heat-resistant. Even high temperature and high pressure cannot decompose it. Currently, there is no specific antidote for fumaric acid poisoning. Once poisoned, the mortality rate is 40% to 100%.

After the toxin enters the human body, the incubation period is generally 30 minutes to 12 hours, and a few people will not develop the disease until 1 to 2 days later. It will attack the liver, kidneys, heart, brain and other important organs. The main manifestations are upper abdominal discomfort, nausea, vomiting, mild diarrhea, dizziness, and general weakness. People with severe symptoms will experience jaundice, hepatomegaly, subcutaneous hemorrhage, hematemesis, hematuria, oliguria, confusion, irritability, convulsions, seizures, shock and even death. Fever symptoms generally do not occur.

If you suspect you have been poisoned by fumonisin, stop eating the suspicious food immediately, then induce vomiting as soon as possible and expel as much of the stomach contents as possible to reduce the absorption of toxins and damage to your body, and go to the hospital for treatment promptly.

How to prevent fumonisin poisoning?

In daily life, there are 3 types of food that are easily contaminated by Pseudomonas cerebrovenans, namely:

Wet rice noodles, rice noodles, potato noodles, and cold noodles;

Soaked black fungus and white fungus;

Foods made with fermented corn flour, glutinous rice flour, sorghum flour, glutinous millet flour, corn starch, etc., such as rice dumplings, glutinous rice cakes, and jelly.

On October 5, 2020, a food poisoning incident caused by eating sour soup occurred in Jidong County, Heilongjiang Province. A total of 9 people were poisoned and all died after rescue efforts failed. Sour soup is a thick strip of food made from corn kernels that are fermented by water milling. It is a traditional food in Northeast China.

These foods have one thing in common, which is that they require long-term soaking or fermentation during production. This long-term humid environment provides a breeding ground for Pseudomonas parahaemolyticus, allowing the toxin aflatoxin to accumulate in large quantities.

To prevent fumonisin poisoning, we have 9 points to note:

1. Choose a regular restaurant: When dining out and eating wet rice noodles, rice noodles, potato noodles, jelly, cold noodles and other foods, pay attention to the restaurant's hygiene conditions and business license.

2. Try to avoid homemade fermented noodles: It is difficult to control the environment of homemade fermented rice and noodles, and the safety factor is low. If you like to eat foods such as sour soup and wet rice noodles, it is best to buy them directly from regular manufacturers and pay attention to factors such as production date, shelf life and storage conditions.

3. Pay attention to the production date and shelf life of the goods: When purchasing the above-mentioned bagged foods in supermarkets and markets, carefully read the product labels and shelf life, and observe their properties with your eyes to see if there are mold spots, black spots, powder spots, green spots, yellow spots, etc. When purchasing black fungus, white fungus or other fermented cereal products and potato products, choose operators with formal qualifications.

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4. Buy in small quantities: When buying the above foods in bulk, confirm their production date and expiration date. Buy in small quantities each time and buy fresh ones after finishing them.

5. Do not eat damp rice noodles, black fungus, white fungus and other foods: Before soaking wet rice noodles, rice noodles, potato flour, or black fungus and white fungus at home, you should check their shape in advance. If they are damp and suspected of being spoiled, do not eat them.

6. Clean before soaking: Before soaking, clean the surface of black fungus and white fungus to reduce the number of Pseudomonas cocosvenorensis.

7. Soak the fungus correctly: The time and environment for soaking the fungus are critical. Do not soak it for too long. It is recommended to control it within 4 hours, and the water temperature should not be too high. Generally, 30℃ is the most suitable temperature. Experiments have shown that if the fungus is soaked for a long time, such as more than 6 hours, the edges of the fungus will crack, which seriously affects the quality of the fungus and is more susceptible to microbial contamination.

8. Proper storage of Tremella: The higher the storage temperature of fresh Tremella, the greater the activity of Pseudomonas cerebrovenanthi and the easier it is to produce fumonisin. After purchasing fresh Tremella, it must be stored at low temperature, refrigerated in a refrigerator at 4°C or frozen, and consumed as soon as possible.

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9. Seek medical attention immediately if you feel unwell: The incubation period of fumonisin poisoning is 30 minutes to 12 hours, 1 to 2 days in a few cases, and 3 days at most. If you feel unwell after eating food suspected of containing fumonisin, you must see a doctor as soon as possible. The earlier you see a doctor, the more hope you have of recovery. Don't rely on luck.

In the hot summer, we should not only prevent food poisoning caused by fumonisin, but also pay attention to the harm caused by food spoilage. Food safety is no small matter, don't regret it for the rest of your life because of the idea that "it's okay to eat it once".

References

[1] Cai Jie, Luo Lin, Liu Xuye, et al. Research progress on detection methods of fumonisin in food[J]. Food Safety Guide, 2023, No.375(10):156-159.DOI:10.16043/j.cnki.cfs.2023.10.050.

[2] Ma Yinpeng, Du Boda, Zhang Jiechi, et al. Study on factors affecting the expansion rate of black fungus[J]. Edible Fungi, 2017, 39(004):62-65.

[3] Ma Tao, Zhang Ligong, He Zhican, et al. Study on the fumonisin of fresh Tremella fuciformis under different storage conditions[J]. Chinese Edible Fungi, 2020, 39(12): 87-91. DOI: 10.13629/j.cnki.53-1054.2020.12.017.

[4] CHEN Jia. Study on the mechanism of Pseudomonas cocovenenans poisoning and its preventive measures[J]. Modern Food, 2019(13):102-104. DOI:10.16736/j.cnki.cn41-1434/ts.2019.13.032.

Author: Zeng Xinyue, popular science creator

Review | Han Hongwei, Researcher at the National Food Safety Risk Assessment Center