Recently, some media reported that a 34 year old woman in Dongguan, Guangdong, soaked Auricularia auricula in water for about 5-6 hours before cooking and eating. She also continued to eat the remaining Auricularia every other day. Soon she had abdominal pain and was found to be caused by Auricularia auricula poisoning when she was admitted to the hospital. However, the toxin had accumulated in the liver and developed acute liver failure, which was not rescued later!
many people like to eat Auricularia auricula, which has high nutritional value. It contains a variety of active substances such as polysaccharides, protein, amino acids, dietary fiber, minerals, melanin, polyphenols and flavonoids. It has a variety of physiological functions such as antioxidant, anticoagulant, prevention of atherosclerosis, hypoglycemia, radiation protection, immune enhancement, anti-tumor and liver protection. It tastes crisp, can be fried dishes, cold mix, also can be made into dumpling stuffing, so it is a common food on the table of many people.
there are also a lot of discussions on the Internet about the poisoning of Auricularia auricula. Some netizens speculated that it was caused by nitrite poisoning caused by Auricularia auricula overnight, but the symptoms of nitrite poisoning were not consistent with the symptoms of the lady.
but according to the information and patient’s symptoms, the real culprit should be a bacterium called Pseudomonas cocoanulata, which produces the lethal toxin, oryzacin!
this kind of bacteria is easy to contaminate fresh Auricularia, and the edible fungus is mostly sold in the form of dried agaric. When Auricularia auricula is dried in the sun, ultraviolet light can kill the bacteria and destroy the toxin, so the dried fungus basically does not contain this toxin.
However, in the process of Auricularia auricula foaming, this kind of bacteria is easy to grow and reproduce, and produce oryzacin. The longer you soak, the more toxins you produce. It may be said that fungus will be heated at high temperature during cooking, and the bacteria and toxins will be destroyed, right?
However, studies have found that this toxin is relatively heat-resistant, and it is difficult to effectively detoxify whether it is washed with water or heated at high temperature. Once a person eats Auricularia Auricularia containing oryzae acid, gastrointestinal and neurological symptoms will appear in the early stage, including nausea, vomiting, abdominal pain, dizziness, etc., and then toxic hepatitis such as liver function damage may occur. In critically ill patients, multiple organ failure or even death may occur. Moreover, the toxicity of the toxin is strong, and there is no specific antidote. According to the data, the mortality rate is as high as 30% – 50%.
since Auricularia can cause poisoning, can’t we eat it any more? In fact, as long as Auricularia is handled properly, the probability of poisoning is very small. In order to prevent similar tragedies from happening again, doctors have put forward several suggestions here:
in fact, similar poisoning incidents have been reported two years ago. A family of three people had similar poisoning after eating agaric soaked for three days. And now it’s summer. The most suitable temperature for the bacteria to grow is 37 ℃, and the temperature for toxin production is 26 ℃. It is the right time for the bacteria to grow and produce toxin. Therefore, doctors suggest not to soak Auricularia auricula for a long time, especially for more than one day.
Finally, regardless of poisoning, Auricularia is still a very nutritious food, so as long as we do the above three points, in fact, agaric can still be eaten.
 Zhang Yanyan, Liu Xinchun, Wang Xue, et al. Research progress on nutritional components and biological activities of Auricularia auricula [J]. Southern agriculture, 2018, 12:130-134
 Shen Tu Ping Ping Ping, Zhu Jiahui, Xu Xiaomin, et al. Investigation on a food poisoning caused by Pseudomonas cocoanulata yeast subsp. [J]. Shanghai preventive medicine, 2019, 31:466-478