Mushrooms and Heavy Metals Abstract
Mushrooms, straw mushrooms, mushrooms, oyster mushrooms, Pleurotus, Flammulina velutipes, black fungus, pine mushroom, bamboo vine, morel, boletus By complexing with heavy metals to generate non-toxic complexes to detoxify them, mushrooms are not afraid of heavy metals. In the environment, especially in polluted environments, there are often a lot of heavy metals, and the mushroom puts these heavy metals in carelessness. "Eating into my own stomach, and accumulating.
The heavy metal content of wild mushrooms is higher than that of artificially cultivated heavy metals. Mushrooms that need to be covered with soil, such as Agaricus bisporus, coprinus comatus, and oyster mushrooms, are easily contaminated by heavy metals in the soil. Relatively speaking, the amount of heavy metals in mushrooms grown from straw is small. For example, a study was conducted in 2007 to investigate the heavy metal content of edible fungi in Beibei District of Chongqing. The area is both an important industrial base and a production base for edible fungi. The researchers analyzed lead, cadmium, mercury and arsenic in Pleurotus ostreatus, Coprinus comatus, Flammulina velutipes, Pleurotus eryngii, and straw mushroom in the area and found that straw mushroom has the strongest ability to accumulate heavy metals. All the samples of straw mushroom are The detected mercury exceeded the standard, one-third of the samples of straw mushrooms exceeded the standard; 14% of the samples of coprinus comatus exceeded the standard; 4% of the samples of the mushrooms exceeded the standard; 29% of the samples of the mushrooms were exceeded.
Researchers at Castilla-La Mancha University in Spain reported in the new issue of Biometals that they had picked up 12 common fungi in several unspoiled wild woodlands in the Spanish city of Ciudad Real. Some of these fungi are edible and some are inedible. The researchers analyzed the contents of heavy metals such as lead, antimony, and tellurium in these fungal samples. The results showed that some wild fungi such as chanterelles contained high levels of heavy metals. Chanterelles is an edible mushroom that is common on Europeans' dinner tables.
Researchers say that chanterelles usually live under trees such as oaks and eucalyptus, and can form symbioses with the roots of these plants. The fungus can directly absorb the mineral components of the soil and then provide nutrients to the plants that are symbiotic with it, eventually obtaining the desired sugar from the photosynthesis of the plant.
The researchers analyzed that this edible mushroom will “absolutely” erode and absorb the mineral components in the soil, and the more mineral components in the soil, the more they are absorbed by this edible mushroom. Therefore, some heavy metals can easily accumulate in chanterelles. Researchers therefore suggest that it is best not to eat wild edible mushrooms that have been picked in areas where the soil is contaminated or that contain special minerals, as these may have higher levels of heavy metals.
In the food chain of "soil-plant-mushroom-human", edible fungi are in a higher position. As edible fungi use plant materials as raw materials for production, the content of heavy metals in edible fungi is generally higher than that of foods such as foods and vegetables, and it may even be higher than animal foods. There is a serious lack of basic data on the content of heavy metals in edible fungi in China, and there is no heavy metal Cd indicator in the National Hygienic Standard for Edible Fungi (GB7096-2004). Excessive heavy metal content is an urgent problem to be solved in the international trade of edible fungi. Chongqing is the largest industrial city in the southwest region. The output and consumption of edible fungi are very large. To study the heavy metal content of major edible fungi in Chongqing and provide basic data for the content of heavy metals in edible fungus in China. Mycelium is the main organization for edible fungi to absorb nutrients, and their characteristics of absorbing heavy metals under liquid culture conditions can provide a theoretical reference for manual control of fruit body absorption of heavy metals. I. Study on the content of heavy metals in major edible fungi in Chongqing The collection of major edible mushroom samples from the representative areas of downtown area of Chongqing, suburbs and suburbs analyzed their heavy metal content. The results showed that the heavy metal content of edible fungus represented the suburbs of the main city near the suburbs. The trend may be related to the background value of heavy metals in the environment. The average lead content of cadmium mercury and arsenic is lower than the national standard, indicating that the heavy metal content of edible fungus in Chongqing is generally safe. However, the lead content of the 12% sample and the mercury content of the 19% sample exceeded the national standard, and the arsenic content of all the samples was lower than the national standard. The average total content of heavy metals in mushrooms Mushrooms coprinus Mushrooms Pleurotus mushroom Pleurotus ostreatus, most of them meet the requirements of national health standards. Specifically, the average total content of mushrooms ((?) = 0.83 mg·kg -1 dry weight) Coprinus comatus (?) = 0.56 mg·kg -1 · dry weight mushroom ((?) =0.52 mg·kg -1 ·dry weight) Hydrangea edodes ((?) = 0.51 mg·kg -1 dry weight) Pleurotus ostreatus ((?) = 0.42 mg·kg -1 ) · Dry weight) Flammulina velutipeti ((?) = 0.39 mg·kg -1 · dry weight), indicating that the ability of different edible fungi to accumulate heavy metals is not the same, and it is necessary to specifically analyze according to the species of edible fungi. Look, Pleurotus ostreatus (CV = 268%) Flammulina velutipes (CV = 261%) Coprinus comatus (CV = 228%) Mushrooms (CV = 180%) Mushrooms (CV = 150%) Himeji (CV = 137%) It is worth noting The coefficient of variation of the total content of heavy metals among different edible mushroom species is large, especially the mushroom, oyster mushroom, and coprinus comatus, and their coefficient of variation is more than 200%, further indicating that the accumulation of heavy metals by edible fungi is not only related to The variety is related, but also affected by other factors such as environmental conditions, cultivation techniques, cultivation materials, etc. Since the cultivation environment in different regions and the heavy metals in the raw materials are not the same, it is speculated that even the heavy metal content in the same edible mushroom may appear Regional differences. In addition, the overall population of different heavy metals The conditions are: the average value of Pb ((?)=1.41 mg·kg -1 - dry weight) Cd ((?) = 0.40 mg·kg -1 dry weight) Hg ((?) = 0.13 mg·kg -1 ·dry weight As ((?) = 0.04 mg·kg -1 ·dry weight), which varies with undetected ~17.28 mg·kg -1 ·dry Weight (Pb), Not detected - 4.31 mg kg -1 dry weight (Cd), Not detected - 2.030 mg kg -1 Dry weight (Hg), Not detected - 0.37 Between mg·kg-1 and dry weight (As), the heavy metal content of edible fungi showed a trend of near suburbs in the remote suburbs of the main city, which may be related to the background values of heavy metals in the environment. The content of heavy metals is not the same, and must be analyzed according to specific conditions.In addition, the coefficient of variation (CV) of heavy metal content in edible fungi is extremely high, Pb(CV=276%)Hg(CV=202%)Cd(CV=185 %)As(CV=126%), all over 100%,
Rumors: Mushrooms should not be eaten. You can eat up to 200g per month. Mushrooms are good, but they have a very important feature, that is, the ability to enrich heavy metals can be up to 100 times more. Almost all heavy metals, such as lead, mercury, nickel, and mushrooms are all enriched. However, our body does not have a mechanism to excrete heavy metals. For a long time, these heavy metals will accumulate in the renal tubules. In severe cases, they even cause necrosis of the renal tubules. The truth: Mushrooms are commonly known as edible fungi, including mushrooms, mushrooms, enoki mushrooms, and coprinus comatus. Compared with green plants, mushrooms are indeed more capable of enriching heavy metals. Foreign researchers have done some investigations on the heavy metal content of wild mushrooms. In recent years, many research institutes in China have investigated artificially cultivated edible mushrooms. For example, a study was conducted in 2007 to investigate the heavy metal content of edible fungi in Beibei District of Chongqing. The area is both an important industrial base and a production base for edible fungi. The researchers analyzed lead, cadmium, mercury and arsenic in Pleurotus ostreatus, Coprinus comatus, Flammulina velutipes, Pleurotus eryngii, and straw mushroom in the area and found that straw mushroom has the strongest ability to accumulate heavy metals. All the samples of straw mushroom are The detected mercury exceeded the standard, one-third of the samples of straw mushrooms exceeded the standard; 14% of the samples of coprinus comatus exceeded the standard; 4% of the samples of the mushrooms exceeded the standard; 29% of the samples of the mushrooms were exceeded.  The excessive occurrence of heavy metals in mushroom foods is not limited to Chongqing. The gold mushroom from the Qinghai-Tibet Plateau has also been found to have excessive levels of cadmium and mercury, and the content of lead and arsenic is much higher than that of mushrooms and bifido mushrooms. . Similar results have been obtained for the study of Ganoderma lucidum, another large fungus. Although it is considered by some to be a magical drug, some researchers have found that some samples are rich in lead. Taiwanese scientists also investigated the Brazilian mushroom (namely, the oyster mushroom, or Agaricus blazei), and found that nearly half of the samples had excessive levels of heavy metal cadmium. However, in 2009, researchers from the Zhejiang Forestry College and other units conducted spot checks on mushroom samples from the Zhejiang market and found no evidence of excessive levels of heavy metals. However, compared with ordinary vegetables, the content was indeed high and exceeded the heavy metal content of vegetables. Limited standards.  However, heavy metal is not an essential element of the mushroom, and there is no benefit to the growth of the mushroom. Why is the content of heavy metals in mushrooms so high? Where do these heavy metals come from? In fact, the reason for the high content of heavy metals is that mushrooms will produce some proteins that can complex with heavy metals and detoxify by complexing with heavy metals to form non-toxic complexes, so that mushrooms are not afraid of heavy metals; in the environment, especially In the polluted environment, there is often a large amount of heavy metals, so the mushroom accidentally eats these heavy metals into their own stomachs and accumulates them. The heavy metals in the mushrooms are different from those produced by some poisonous mushrooms themselves. They come from the environment and are not what they want. If the culture medium is not contaminated, our favorite mushroom is still a good food. Some farmers do not understand the environment and use silt to grow mushrooms. Although there are many nutrient elements in the sludge, if the natural water bodies such as rivers cause excessive levels of heavy metals in the sewage due to the sewage, using it to grow mushrooms may cause severe excessive levels of heavy metals in the mushrooms. So, do these heavy metals affect the human body? Think about it. Mushrooms process the heavy metals they absorb by synthesizing their complex proteins. It is said that humans “have no mechanism for removing heavy metals” and they are somewhat self-conscious. In fact, similar functions of metallothionein are also present in the human body, and if the amount of heavy metals in the body increases, it will induce more metallothioneins and increase the detoxification capacity. In addition, glutathione in the liver also binds with heavy metal ions and is further excreted through the digestive tract for detoxification. For some specific heavy metals, there will be specific ways of metabolism to achieve detoxification and excretion. For example, arsenic can be converted into less toxic monomethyl arsenic and dimethyl arsenic in the human body and is more easily excreted. Kidneys, livers, even lungs and other organs have the function of discharging heavy metals. In general, our ability to metabolize heavy metals is our ability to protect us from their toxic hazards, unless we continue to ingest large amounts of toxic heavy metals over long periods or over time. Judging from the findings of some scientific research institutions that do not have food regulatory functions, there is indeed a phenomenon of heavy metals exceeding the standard in mushrooms on the Chinese market. Then, what do we like to eat mushrooms? In general, the heavy metal content of wild mushrooms is higher than that of artificially cultivated heavy metals. Mushrooms that need to be covered with soil, such as Agaricus bisporus, coprinus comatus, and oyster mushrooms, are easily contaminated by heavy metals in the soil. Relatively speaking, the amount of heavy metals in mushrooms grown from straw is small. As an ordinary person, it is difficult for us to accurately determine the heavy metal pollution in food. We hope that our environmental monitoring department and food safety management department will be able to work harder for ourselves, and even for our descendants, to leave a more secure agricultural economy. Conclusion: Partially confirmed. Mushrooms such as edible fungi may indeed have excessive heavy metals, which is related to whether the culture medium contains large amounts of heavy metals. The body itself has the ability to metabolize heavy metals, but if long-term sustained doses of ingestion of toxic heavy metals can indeed bring harm.