Difference Between Poisonous and Edible Mushroom

MUSHROOM Mushrooms are fleshy spore of fungi group on organic substrate and for a long time, playing an important role as a human food, due to its nutritional and medicinal properties. They are source of proteins, minerals and vitamins. The symptoms of mushroom poisoning can vary from slight gastro-intestinal discomfort, vomiting to death. It may also vary from gastric upset to lifethreatening organ failure resulting in death. Incubation period may range from a day to several weeks after which serious symptoms will occur and before this time the toxins must have attacked the kidney or liver. Edible mushrooms are treated as a garnish or delicacy which can be taken regularly as part of the human diet, healthy food or as functional foods. The major problem arising from eating mushrooms is the inability of mushroom gatherers or mushroom scientists to identify the poisonous mushrooms which contain toxins and can be very detrimental to human health. It has been reported in study that poisonous mushrooms have killed many life in different parts of the world including Nigeria due to the misidentification of poisonous mushrooms as edible mushrooms. Therefore, the main objective of this study is to describe the nutrition, toxicity and strategies for recognition of wild edible and non-edible mushrooms using the physical (morphology), traditional (nonscientific) and chemical (scientific) approaches of identification. 1 DIFFERENCE MUSHROOM BETWEEN EDIBLE AND POISONESS Edible Mushrooms: Edible mushrooms are the fungi which bear fruiting structures that are large enough to be seen with the naked eye. They may be hypogeous or epigeous and can be picked by hand. What underscores edibility of mushrooms is the absence of poisonous effects on humans and desirable taste and aroma. The nutritional composition of edible mushrooms is high and that is why they are consumed for their nutritional value and supposed medicinal value. Medicinal mushrooms are consumed by those practicing folk medicine for their neutriceutical composition. The hallucinogenic mushrooms like psilocybin mushrooms are consumed for recreational or religious purposes and they can produce severe nausea and disorientation – a reason why they are not commonly considered edible mushrooms. Poisonous Mushrooms Since there is no known test by which to tell if a mushroom is edible or not, a mushroom should never be eaten unless it has been accurately identified and the edibility of the species is known. Poisonous mushrooms represent less than 1% of the world’s known mushrooms hence constitute the dangerous and sometimes fatal species. For this reason, mushrooms must be identified by a competent mycological authority before consumption. Therefore, one must be absolutely sure whether a given mushroom is edible or otherwise before consumption. The toxins contained in various species are very different in chemical composition, thus the effects of poisoning differ considerably according to the species involved. In any case, suspected mushroom poisoning should never be regarded lightly and medical assistance should be sought at once. The following summary of mushroom poisoning is taken from the account. 2 Edible mushroom When you cut the mushroom it does not stain green or purple. When you taste a piece of the mushroom, it does not burn or sting the tongue Edible mushrooms have pleasant odour It has sweet taste There is presence of worms There is no scale on the cap Poisonous mushroom When you cut the mushroom it turns either green or purple When you taste a piece of the mushroom, it burns or stings the tongue Poisonous mushrooms have bad odour. It tastes bitter There is no presence of worms There is presence of scale on the cap POISONOUS MUSHROOMS 1) Amanita-type poisoning The Amanita phalloides group causes the most dangerous type of mushroom poisoning. The toxins involved belong to the phallotoxin and amatoxin complexes. The phallotoxin phalloidin binds specifically to actin. The phallotoxins are not active following ingestion, but they are potent when injected intravenously and have proved useful in experimental studies. In such studies phalloidin, binding to actin, is coupled with fluorescent groups. By this means actin can be localized in the cells. It is the amatoxin such as amatine that is involved in amanita poisoning. Amatine is a specific inhibitor of RNA polymerase present in all eukaryotes. This blocking of the enzymes associated with the replication of RNA inhibits the formation of new cells. These toxins tend to accumulate in the liver and damage that organ severely. The RNA polymerase of the fungus is not affected. This group has caused the majority of recorded deaths from mushroom poisoning, especially in Europe. Generally, the symptoms of this type of poisoning are said to be severe abdominal pains, nausea, violent vomiting, diarrhoea, cold sweats, and excessive thirst. These may last for 48 hours, with dehydration, cramps, and anuria. 3 2) Muscarine-type poisoning Two toxins, muscarine and ibotenic acid, are involved. They occur in Amanita muscaria, A. pantherina, and also in a number of Inocybe and Clitocybe species. Muscarine is known to be responsible for “pupil contraction, blurred vision, lachrymation, salivation, perspiration, reduced heart rate, lowering of blood pressure, and asthmatic-like breathing.”. Ibotenic acid is responsible for the insecticidal properties of A. muscaria, the fly agaric. Both muscarine and ibotenic acids are intoxicants, and there is a long history of different cultures using these compounds from A. muscaria for this purpose and in religious rites. The symptoms usually appear soon after eating the mush- rooms, with vomiting, diarrhea, and salivation. The most characteristic symptoms are nervous excitement, difficulties in breathing, shivering, and a tendency to collapse. 3) Psychotropic or hallucinogenic poisoning Several different toxins are involved, including psilocin and psilocybin, which are found in species of Psilocybe, Conocybe, and Stropharia. These compounds are similar in their reaction to d-lysergic acid diethylamide. They act on the central nervous system, producing distortions in vision and of tactile sensations as well as mixed emotional feelings of happiness or depression. Other symptoms are varied, including vomiting, increased rate of heartbeat, and hallucinations, which may last for various lengths of time. 4) Coprinus poisoning Several Coprinus species, such as C. Micaceus and C. Atramentarius, when consumed with an alcoholic drink, produce unpleasant but not dangerous symptoms. The symptoms include reddening of the face, increased rate of heartbeat, and, in some cases, vomiting and diarrhoea. The mode of action of the chemical in C. Atramentarius mushrooms is similar to Antabuse, which is a drug used to induce nausea and vomiting in individuals who are trying to overcome an addiction to alcohol. 4 5) Poisoning from external sources The poisoning is not caused by mushrooms themselves but by toxic substances that have accumulated in the mushrooms. The principal causes are: (1) Heavy metals due to polluting environmental conditions where the mushrooms are harvested that are far in excess of permissible levels. (2) Radioactive contaminants due to the pollution by contaminating radioactive materials in mushroom hunting areas and subsequent consumption of the collected mushrooms. 5