Can we eat the green onion?

Every summer, it is the season for eating mushrooms in Yunnan. In recent years, the green mushroom that can make people see "villains" and fall into magic has become popular. This green mushroom is called "red onion" by Yunnan people. Its scientific name is Lanmaoa asiatica. It is one of the most popular mushrooms in the area. Why is it listed as a poisonous mushroom when it is so delicious? If it is poisonous, why do our ancestors still eat it?

Image source: provided by the author

Image source: provided by the author

Part 1

Before eating, you need to know

As the name suggests, Jianshouqing is a type of boletus that turns green (blue) when touched. Studies have shown that the green (blue) color is likely due to the oxidation of hydroxylated pulvinic acid derivatives, such as variegatic acid and xerocomic acid, which are rich in boletus, into quinone methide derivatives.

The common types of boletus on the market are mainly the following: Lanmao boletus, rose-yellow boletus, tea-brown boletus, gorgeous boletus, ochre-capped boletus, yellow-hole boletus, red-hole boletus, etc. Sometimes they are mixed with thin-fleshed boletus and poisonous boletus.

Different types of safflower (provided by the author)

In fact, there are many more species of Boletus than the above ones. They have a large and complex "family" relationship. However, all you need to know is that the Boletus that turns green (blue) when injured is not "a" Boletus, but "a type" of Boletus! So the question is, are these Boletus poisonous?

Part 2

Is it poisonous?

At present, there are relatively few studies on the chemical composition of the green lily, but we can still infer which green lilies are poisonous from the cases of poisoning caused by ingestion of poisonous mushrooms in Yunnan every year.

It is understood that researchers have systematically analyzed 223 poisoning incidents in Yunnan that have been scientifically identified since 2013, and found 47 poisonous mushrooms, including six species of Boletus, namely Baorangia pseudocalopus, Baorangia major, Boletellus indistinctus, Neoboletus venenatus, Rubroboletus sinicus and Lanmaoa asiatica. The first five types of poisoning are gastroenteritis, while Lanmaoa asiatica, commonly known as red onion, often causes neuropsychiatric poisoning.

Among the fungi that cause gastroenteritis-type poisoning, the first one is the new boletus, and its toxicity can probably be felt from its scientific name. In the past, many people thought that eating fungi was fine, at most it would cause diarrhea and see magical villains, but the actual situation may be much more serious than this. The new boletus can cause severe gastrointestinal discomfort and dehydration, and even endanger life. Its toxicity may come from the toxic protein bolevenine in its body, which is similar to the toxic protein bolesatine of the devil red hole boletus (Rubroboletus satanas, a type of fungi) from Europe, which can also endanger life.

As for the red onion (Lamborough Boletus), which is of most concern to everyone, although its toxin is still unknown, it is a "frequent guest" on the table and has caused many neuropsychiatric poisoning incidents with hallucinations and auditory hallucinations. The symptoms of this kind of hallucinations and auditory hallucinations are also diverse, often different from what we call "seeing magic people", and unpleasant experiences also occur from time to time.

Part 3

Is it really true that I can’t touch it at all?

However, you don’t have to worry too much about shallots. Since our ancestors have been eating shallots for generations, it means that it is safe as long as you eat it correctly. Just like pufferfish, almost everyone knows that it is poisonous, and the toxicity is not small, but as long as you handle it properly, you can avoid pufferfish toxin poisoning.

In fact, shallot poisoning is mainly caused by "careless" cooking (undercooked or left overnight and eaten cold). Therefore, we would like to remind you that shallot is a conditionally edible (or conversely, conditionally poisonous) shallot. If it is cooked properly (cooking is the key, and it should be eaten at the same meal), the toxins in it can be destroyed and degraded, and it will become a superior "mountain delicacy". If it is not cooked properly, the probability of you being poisoned is very high.

Friends who have eaten wild mushroom hotpot in Yunnan restaurants should know that if you order jianshouqing, the waiter will definitely put a timer on your table, set it for 20 to 30 minutes, and tell you repeatedly that you must wait until the timer is over before you can start eating. They do this not for formality or to create an atmosphere, but because of their past experience and it has scientific reasons.

Image source: veer gallery

Image source: provided by the author

As a common wild mushroom in the Yunnan wild mushroom market, red onions have always been popular because of their unique taste. When selling red onions, sellers are advised to remind buyers (especially those from other places) that red onions are toxic. Diners should not be "blinded" by the deliciousness. They must be cooked properly and eaten as a meal after being cooked thoroughly. After all, you can't eat red onions in a hurry.

Produced by: Science Popularization China

Produced by: Wu Gang (Kunming Institute of Botany, Chinese Academy of Sciences)

Producer: China Science Expo

The article only represents the author's views and does not represent the position of China Science Expo

This article was first published in China Science Expo (kepubolan)

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