It was reported earlier that few citizens felt unwell after consuming boletoid mushrooms imported from China. Some people may wonder, “Aren’t boletoid mushrooms edible?” The fact is that there are so many species of boletoid mushrooms, and some of them are toxic.
In China, 397 mushroom species belong to the family Boletaceae, of which only 33 species are toxic1. Since poisonous and non-poisonous species have similar morphological features, accidental harvesting and consumption of toxic boletoid mushrooms are not uncommon. Depending on the amount and species consumed, different mushroom poisoning symptoms may occur:
Although the toxin compositions within boletoid mushrooms are complicated, there are only a limited number of relevant studies. Examples of well characterized toxins include toxic proteins and hallucinogens. On the other hand, it is noted that the types and amounts of toxins within a mushroom could vary with time and its geographical location.
Chromatographic techniques (e.g. HPLC) can be used to check whether a boletoid mushroom contains the well characterized toxins. However, they are not ideal for identifying toxins of unknown chemical natures.
As such, botanical identification is the most widely used method to tell whether a boletoid mushroom is toxic or not. This depends on the ability and experience of mushroom harvesters and merchandisers to identify toxic mushroom species.
The fact, however, is that incidents of mixing edible mushroom species with toxic ones still occur from time to time. This is because not all mushroom harvesters and merchandisers are well trained in species identification. Moreover, on occasion, different literatures have different stances on the toxicity of a species, this can lead to confusion.
In order to prevent accidental harvesting and importation of toxic mushroom species from happening, it is necessary to enhance public education and training. Moreover, mushroom identification should be done scientifically and objectively. Since molecular biotechnology is already well developed, many testing laboratories can rapidly and accurately identify the species of a boletoid mushroom through the gene sequence analysis.