Mycotoxins(from the Greek mukes - fungus and toxicon - poison) are secondary metabolites of microscopic molds that have pronounced toxic properties.
Currently, more than 250 species of mold fungi are known to produce about 100 toxic compounds that cause alimentary toxicosis in humans and animals.
Mold fungi affect products of both plant and animal origin at any stage of their production, transportation and storage, in industrial and domestic conditions. Untimely harvesting or insufficient drying before storage, storage and transportation of products with insufficient protection from moisture lead to the multiplication of microorganisms and the formation of toxic substances in food products.
Mycotoxins can also enter the human body through food products - with meat and milk of animals fed with food contaminated with mold fungi.
Reproducing on food, many mold fungi not only pollute them with toxins, but also worsen the organoleptic properties of these products, reduce nutritional value, lead to spoilage, and make them unsuitable for technological processing. The use of feed contaminated with fungi in animal husbandry leads to the death or disease of livestock and poultry.
The annual damage in the world from the development of mold fungi on agricultural products and industrial raw materials exceeds 30 billion dollars.
Among mycotoxins, aflatoxins, ochratoxins, patulin, trichothecenes, zearalenone stand out with toxic and carcinogenic properties.
Given the wide distribution of mycotoxins in the world, the country monitors imported products for contamination with mycotoxins.
Aflatoxins are one of the most dangerous groups of mycotoxins with strong carcinogenic properties.
Producers of aflatoxins are some strains of 2 species of microscopic fungi: Aspergillus flavus and Aspergillus parasiticus. The main metabolites of these microfungi are two compounds that emit a blue glow under ultraviolet irradiation - aflatoxins B1 and B2, and two compounds that emit a green glow when irradiated - aflatoxins G1 and G2. These four aflatoxins make up a group commonly found in foods contaminated with microfungi. Aflatoxins are thermostable and remain toxic under most types of food processing.
Aflatoxins were first discovered in peanut seeds and products derived from them. Often the source of aflatoxins is the grain of corn, millet, rice, wheat, barley, nuts - pistachios, almonds and other nuts, cocoa beans and coffee, some vegetables and fruits, as well as cotton seeds and other oil plants. Aflatoxins are found in small amounts in milk, meat, and eggs.
The establishment of high toxicity and carcinogenicity of aflatoxins and their detection in significant amounts in staple foods around the world has led to the need to develop effective methods for detoxifying raw materials, food and feed.
Currently, for this purpose, a set of measures is used, which can be divided into mechanical, physical and chemical methods for detoxifying aflatoxins. Mechanical methods of detoxification are associated with determining the contamination of raw materials manually or with the help of electronic colorimetric sorters. Physical methods are based on fairly severe heat treatment (for example, autoclaving), and are also associated with ultraviolet irradiation and ozonation. The chemical method involves the treatment of the material with strong oxidizing agents. Unfortunately, each of these methods has significant drawbacks: the use of mechanical and physical methods does not give a high effect, and chemical methods lead to the destruction of not only aflatoxins, but also beneficial nutrients and disrupt their absorption.
Ochratoxins- compounds of high toxicity with a pronounced teratogenic effect.
Producers of ochratoxins are microscopic fungi of the genus Aspergillus and Penicillium. The main producers are A. ochraceus and P. viridicatum. Numerous studies have shown that the most common natural pollutant is ochratoxin A, in rare cases ochratoxin B.
The main plant substrates in which ochratoxins are found are cereals and among them corn, wheat, barley. It is regrettable that the level of contamination of feed grains and animal feed is above average in many countries (Canada, Poland, Austria), in connection with which ochratoxin A was found in animal products (ham, bacon, sausage). Ochratoxins are stable compounds. So, for example, during prolonged heating of wheat contaminated with ochratoxin A, its content decreased only by 32% (at t = 250 - 3000C).
Trichothecenes. This class of mycotoxins is produced by various species of microscopic fungi Fusarium and others. More than 40 trichothecene metabolites are known, some of them are biologically active, while others are extremely potent toxins.
At present, in our country and abroad, there is an increase in the disease of wheat, barley and other spiked crops with Fusarium. The most severe damage to the crops of these crops was in 1988. in the Krasnodar Territory, a number of regions of Ukraine and Moldova, which was facilitated by a rainy summer, high temperature and humidity.
According to the degree of infection, Fusarium grain is distinguished, grain with signs of Fusarium and grain seeded from the surface with spores and mycelium of Fusarium without changing its properties.
Fungi of the genus Fusarium produce fusariotoxins on grain. The most common fusariotoxin is vomitoxin.
There are two known human diseases associated with grain products contaminated with Fusarium fungi. One of them, called "drunken bread", occurs when fusarium grains are used in food. The disease is accompanied by digestive disorders and nervous phenomena - a person loses coordination of movements. Farm animals are also subject to poisoning with "drunk bread".
The second disease - alimentary toxic aleukia - was noted in the USSR during World War II when grain that overwintered under the snow was used as food. The disease was caused by toxic strains of microfungi that released toxic lipids into the grain. Millet and buckwheat that have overwintered under snow are the most toxic, wheat, rye and barley are less dangerous.
In accordance with the standards established by the Ministry of Health, accepted wheat grain can be used for food purposes if the vomitoxin content is not more than 1 mg/kg in strong and durum wheat and up to 0.5 mg/kg in soft wheat. For fodder purposes, grain can be used at vomitoxin concentrations of not more than 2 mg/kg.
Zearalenone and its derivatives are produced by microscopic fungi of the genus Fusarium. It was first isolated from moldy corn. The main producers of zearalenone are Fusarium graminearum and F.roseum. Zearalenone has pronounced hormonal properties, which distinguishes it from other mycotoxins.
The main natural substrate in which zearalenone is most often found is corn. The defeat occurs both in the field, on the vine, and during its storage. The frequency of detection of zearalenone in mixed fodders, as well as in wheat and barley, and oats is high. Among foods, this toxin has been found in cornmeal, cereal, and corn beer.
3 .4 Patulin and some other mycotoxins
Mycotoxins produced by microscopic fungi of the genus Penicillium are ubiquitous and pose a real danger to human health. Patulin is a particularly dangerous mycotoxin with carcinogenic and mutagenic properties. The main producers of patulin are microscopic fungi of the genus Penicillium patulum and Penicillium expansu.
Patulin producers mainly affect fruits and some vegetables, causing them to rot. Patulin is found in apples, pears, apricots, peaches, cherries, grapes, bananas, strawberries, blueberries, lingonberries, sea buckthorn, quince, and tomatoes. Most often, patulin affects apples, where the content of the toxin can reach up to 17.5 mg/kg. Interestingly, patulin is concentrated mainly in the rotten part of the apple, in contrast to tomatoes, where it is distributed evenly throughout the tissue.
Patulin is also found in high concentrations in processed fruits and vegetables: juices, compotes, purees and jams. Especially often it is found in apple juice (0.02 - 0.4 mg / l). The content of patulin in other types of juices: pear, quince, grape, plum, mango - ranges from 0.005 to 4.5 mg/l. Interestingly, citrus fruits and certain vegetable crops such as potatoes, onions, radishes, radishes, eggplants, cauliflowers, pumpkins and horseradish are naturally resistant to patulin-producing fungi.
Among the mycotoxins produced by microscopic fungi of the genus Penicillium and representing a serious danger to human health, it is necessary to single out luteoskirin, cyclochlorotin, citreoviridin and citrinin.
1The manual was written in accordance with the State Educational Standard of the Higher Professional Education of the Russian Federation, the GPD cycle and the work program of the discipline "Safety of food raw materials and food products" for the specialty 260202 - "Technology of bread, confectionery and pasta" direction 260200 "Production of food products from vegetable raw materials".
The tutorial contains the following sections:
Introduction
1. Normative and technical documentation in the field of food safety
2. Classification of foreign pollutants - xenobiotics. The main routes of their entry into food
3. Environmental substances of chemical (anthropogenic) origin
3.1. Toxic elements
3.2. Radionuclides
3.3. Dioxins and dioxin-like compounds
3.4. Polycyclic aromatic and chlorinated hydrocarbons
3.5. Packaging materials and containers as a source of food contamination with xenobiotics
4. Substances used in crop production
4.1. Pesticides and their metabolites
4.2. Nitrates, nitrites and nitroso compounds
4.3. Plant growth regulators
5. Substances used in animal husbandry
6. Substances from the environment of biological origin
6.1. Microbiological indicators of the safety of raw materials and food products
6.2. Microorganisms that develop in food products and their metabolites
6.2.1. Surface microflora of grain
6.2.2. Diseases of bread caused by microorganisms and measures for their prevention
6.2.3. Mycotoxins
6.2.4. Features of grain that overwintered in the field
6.2.5. Ways to improve the safety of raw materials in the production of grain bread
6.2.6. Harmful microorganisms of confectionery production and ways of their penetration
6.2.7. Microbiological spoilage of finished products of confectionery production and measures to combat it
6.2.8. Sanitary and hygienic regimes by stages of production and departments
7. Natural components of food that have a harmful effect on the human body (anti-alimentary factors)
7.1. Digestive enzyme inhibitors
7.2. Cyanogenic glycosides
7.3. Lectins
7.4. alkaloids
7.5. Antivitamins
7.6. Factors that reduce the absorption of minerals
8. Food additives and control of their use
9. Genetically modified food
Terms and Definitions
Subject index
Bibliographic list
The manual deals with such issues as ensuring the quality of food raw materials and food products; contamination with xenobiotics of chemical and biological origin, microorganisms and their metabolites; chemical elements, substances and compounds used in crop production and animal husbandry; radioactive substances and dioxins; control over the use of food additives; detox methods.
The manual is presented in nine chapters. Chapter one is devoted to issues of Russian legislation in the field of food products. In the remaining eight chapters, the material is presented in a logical sequence on the topics: “Classification of alien pollutants - xenobiotics”, “Environmental substances of chemical (anthropogenic) origin”, “Substances used in crop production”, “Substances used in animal husbandry”, “Substances from environment of biological origin", "Natural food components that have a harmful effect on the human body", "Food additives and control over their use" and "Gene-modified food".
The level of presentation of the material corresponds to the modern achievements of science in the field of ensuring the safety of raw materials and food products. When preparing sections of the manual, interdisciplinary links with such disciplines as "Inorganic Chemistry", "Organic Chemistry", "Physics", "Introduction to Food Technology", etc. are observed. The available literature on the discipline under study is used quite fully.
A clear and accessible presentation of the material, the design of reference data in the form of tables and figures will allow more efficient use of this manual in self-preparation of students.
The textbook manuscript meets modern requirements for the training of qualified specialists; may be useful to students, graduate students, engineers and technicians of the food industry, in particular, the baking industry. The manual can be recommended for students of the system of advanced training and retraining of personnel.
Bibliographic link
Zharkova I.M., Malyutina T.N. SAFETY OF FOOD RAW AND FOOD PRODUCTS // Modern problems of science and education. - 2009. - No. 1.;URL: http://science-education.ru/ru/article/view?id=856 (date of access: 04/29/2019). We bring to your attention the journals published by the publishing house "Academy of Natural History"
Mycotoxins. Mycotoxins (from the Greek mukes - fungus and toxicon - poison) are toxic waste products of microscopic mold fungi that have pronounced toxic properties.
Molds are ubiquitous microorganisms. Their role in storage spoilage is as well known as their use in enzymatic processes in the manufacture of certain types of cheese or in the microbiological synthesis of citric acid and penicillin. The toxicity of moldy food and feed has been known for a relatively long time.
The problem of mycotoxins has been known since ancient times. Periodically, poisoning of people and animals occurred when using products containing mycotoxins. The most famous death of 14 thousand people in Paris in 1129 from the use of bread containing mycotoxin (ergotoxin) of ergot cereals. In Russia, there have also been cases of mass poisoning of people and animals with grain and bread containing Fusarium mycotoxins. Since approximately the 60s of the 20th century, the problem of mycotoxins has become global in nature due to the violation of the ecological balance with intensive crop cultivation technologies, as well as due to the increase in the content of photooxidants in the atmosphere (air pollution), which causes plants to lose resistance to phytopathogens. The increase in mycotoxicosis of agricultural products is also associated with the widespread use of nitrogen fertilizers and pesticides. The limited number of genotypes of crop varieties is also important. Currently, there are no effective chemical methods to combat the contamination of cereal crop products with mycotoxins.
The distribution of mycotoxins in foodstuffs depends on their production by specific strains of fungi and is influenced by factors such as humidity and temperature. Thus, contamination of food products may vary depending on geographical conditions, methods of production and storage, type of product. Mycotoxin-producing fungi are widespread in nature and can develop on almost all products of both plant and animal origin with the formation of toxins at any stage of their production - in the field, during harvesting, transportation, storage of crops, in the process of culinary processing.
Toxins are not removed from foods by conventional cooking methods. Reducing the content of toxins in products can be achieved by proper storage of the crop, the use of resistant varieties, pesticides. It is characteristic that the seeds in which toxins are concentrated differ in color and can and should be separated.
Mycotoxins are the most important secondary metabolites of microscopic fungi, which over the past 35–40 years have been recognized as one of the most harmful agents for human and animal health and have been included in the list of substances regulated in food products, feed and raw materials. The high danger of mycotoxins is expressed in the fact that they have a toxic effect in extremely small quantities and are able to diffuse very intensively deep into the product.
More than 300 mycotoxins produced by representatives of 350 species of microscopic fungi have been isolated, but only about 20 have practical significance as food contaminants. Many of them have mutagenic (including carcinogenic) properties. Among the mycotoxins that pose a threat to human and animal health, the most common are aflatoxins (formula I and II), trichothecene mycotoxins, or trichothecenes (III–IV), ochratoxins (V), patulin (VI), zearalenone and zearalenol (VII), formulas whose representatives are given in Table 3.2. Most mycotoxins are crystalline substances (Table 3.3), thermally stable, and readily soluble in organic solvents. Mycotoxins (with the exception of ochratoxins) are sufficiently resistant to the action of acids, are destroyed by alkalis with the formation of non-toxic or low-toxic compounds.
For many of mycotoxins, the structure has been established, properties and biochemical mechanism of action have been studied, and methods for isolation, identification, and quantification have been developed. These include aflatoxins, ochratoxins, patulin, citrinin, zearalenone, trichothecene mycotoxins. Given that mycotoxins, in addition to general toxic effects, have mutagenic, teratogenic, and carcinogenic properties, and also significantly affect the immune status of warm-blooded animals, they should be considered as one of the most important medical problems.
The potential and real danger of mycotoxins is greatly enhanced by their high stability to various adverse
Table 3.2. – Mycotoskins, the most common in food
|
Name |
|
|
Group I: Aflatoxin B 1: R=H, m.m. – 312 Aflatoxin B 2: R=H, positions 8 and 9 are hydrogenated, m.m. – 314 Aflatoxin M 1: R=OH, m.m. – 328 |
|
|
|
Group II: Aflatoxin G 1: m.m. – 328 Aflatoxin G 2: positions 9 and 10 are hydrogenated, m.m. – 330 |
|
|
Group III: Toxin T-2: R 1 \u003d OH, R 2 \u003d R 3 \u003d OAc, R 4 \u003d H, R 5 \u003d OCOCH 2 CH (CH 3) 2, m.m. – 424 HT-2 toxin: R 1 \u003d R 2 \u003d OH, R 3 \u003d OAc, R 4 \u003d H, R 5 \u003d OCOCH 2 CH (CH 3) 2, m.m. – 466 Diacetoxyscirpenol (DAZ): R 1 =OH, R 2 =R 3 =OAc, R 4 =H, R 5 =CH 2, m.m. – 366 |
|
|
Group IV: Nivalenol: R 1 \u003d R 2 \u003d R 3 \u003d R 4 \u003d OH, m.m. – 312 Deoxynivalenol (DON) : R 1 \u003d R 3 \u003d R 4 \u003d OH, R 2 \u003d H, m.m. – 296 3-acetyl-deoxynivalenol: R 1 \u003d OAc, R 2 \u003d H, R 3 \u003d R 4 \u003d OH, m.m. – 338 15-acetyl-deoxynivalenol: R 1 \u003d R 4 \u003d OH, R 2 \u003d H, R 3 \u003d OAc, m.m. – 338 Fuzarenone: R 1 \u003d R 3 \u003d R 4 \u003d OH, R 2 \u003d OAc, m.m. – 354 |
|
|
Group V: Ochratoxin A: R=H, R 1 =Cl, m.m. – 403 Ochratoxin B: R=H, R 1 =H, m.m. – 369 Ochratoxin C: R=Cl, R 1 =C 2 H 5 , m.m. – 431 |
|
|
Group VI: Patulin: m.m. – 153 |
|
|
Group VII: Zearalenone: X= CO, m.m. – 318 Zearalenol: X= CHOH, m.m. – 312 |
Table 3.3. – Basic physical and chemical properties of mycotoxins
|
Mycotoxin |
Fluorescence |
|||||
| Aflatoxin B 1 |
Blue, 425 |
|||||
| Aflatoxin G 1 |
Green, 450 |
|||||
| Aflatoxin M 1 |
Blue, 425 |
|||||
| Toxin T-2 | ||||||
| Diacetoxyscirpenol | ||||||
| Deoxynivalenol | ||||||
| Nivalenol | ||||||
| Zearalenone |
blue green |
|||||
| Patulin | ||||||
| Ochratoxin A |
Green, 475 |
|||||
| Ochratoxin B | ||||||
|
Notes: |
Solvent methanol. |
|||||
|
No UV absorption or fluorescence. |
||||||
influences, such as: boiling, treatment with mineral acids, alkalis and other agents.
The geography of distribution of mycotoxins covers most countries of all continents. All major food products, feed, food raw materials are subject to contamination with mycotoxins, and intensive trade relations between different countries greatly contribute to the spread of both mycotoxins and mycotoxicoses, so this problem is global in nature.
Aflatoxins. This group of the most dangerous mycotoxins includes more than 15 of their representatives, which are produced by fungi. Aspergillus flavus and Aspergillus parasiticus. These fungi are ubiquitous, which explains the significant extent of their contamination of food and feed. Mushroom reproduction Aspergillus associated with a certain set of conditions: high carbohydrate levels, low protein content, the presence of metal ions such as Cd 2+ , Mg 2+ , Ca 2+ , Zn 2+ . Of particular importance is zinc, because it is intensively consumed in the synthesis of aflatoxins. The development of aflatoxin-producing fungi is influenced by product and air humidity, air temperature, illumination, and pH. The optimal temperature for the formation of toxins is 27-30ºС, although the synthesis of aflatoxins is possible at lower (12-13ºС) or higher (40-42ºС) temperatures.
A critical factor that also determines the growth of microscopic fungi and the synthesis of aflatoxins is the humidity of the substrate and atmospheric air. The maximum synthesis of toxins is observed at a humidity above 18% for substrates rich in starch (wheat, barley, rye, oats, rice, corn), and above 9–10% for substrates with a high lipid content (peanuts, sunflower, various types of nuts) . At relative air humidity below 85%, the synthesis of aflatoxins stops.
According to their chemical structure, aflatoxins are furocoumarins (Table 3.3).
Aflatoxins are slightly soluble in water (solubility is about 10–20 mg/l), insoluble in non-polar solvents, but readily soluble in solvents of medium polarity, such as chloroform, methanol, dimethyl sulfoxide, etc.
Aflatoxins have the ability to strongly fluoresce when exposed to long-wavelength UV radiation. Aflatoxins B 1 and B 2 have blue-blue fluorescence, G 1 and G 2 - green fluorescence, M 1 and M 2 - blue-violet (B 1: l ex \u003d 265 360 nm, l em \u003d 425 nm).
This property underlies almost all physicochemical methods for their detection and quantification and makes it possible to determine aflatoxins at low concentrations (M 1 in milk 0.02 µg/l). The ability to fluoresce also served as the basis for the name of aflatoxins: group B - blue fluorescence ( blue), G – green ( green). The subscripts are related to the chromatographic mobility of the compound.
As pure substances, aflatoxins are extremely thermally stable when heated in air, but are relatively easily destroyed by light, especially UV rays.
Aflatoxins (mainly toxin B) are major food contaminants. Aflatoxins B 1 , B 2 , G 1 and G 2 are highly toxic (for aflatoxin B 1 LD 50 = 7.8 mg/kg (macaque, oral)). Aflatoxins or their active metabolites act on almost all cell components. Aflatoxins impair the permeability of plasma membranes. The toxic effect is due to their interaction with the nucleophilic regions of DNA, RNA and proteins. The biological activity of aflatoxins manifests itself both in the form of an acute toxic effect and long-term consequences - carcinogenic, mutagenic and teratogenic effects. The acute toxic effect of aflatoxins is due to the fact that they are one of the most powerful hepatropic poisons, the target organ of which is the liver. Aflatoxins are especially dangerous for children, as they sharply inhibit their growth, physical and mental development, and reduce resistance to infectious diseases. Gradually accumulating in the body, aflatoxins in a decade, two, three can cause liver cancer.
One of the proofs of the real danger of aflatoxins is the fact that in a number of countries in Africa and Asia, where acute aflatoxicoses are observed in humans, a direct correlation has been found between the incidence of liver cancer in the population and the content of aflatoxins in food products.
Currently, the main toxin regulated in food products is aflatoxin B 1 . Its MPC in Germany is 2 µg/kg, 5 µg in France and 1 µg in Sweden. In Russia and the Republic of Belarus, the norm for all food products, except milk, is 5 μg / kg B 1 and for milk and dairy products - 0.5 μg / kg M 1 (with an unacceptable content of aflatoxin B 1 in them). Permissible daily dose - 0.005-0.01 mcg / kg of body weight.
Under natural conditions, aflatoxins contaminate peanuts, corn, some cereals, cocoa beans, oilseeds, and their processed products. Aflatoxins can also accumulate in cocoa beans, coffee and a number of other food products, in the feed of farm animals. Aflatoxin contamination is a serious problem for agricultural plant products from countries and regions with a subtropical climate. Optimal conditions for the formation of aflatoxins can also occur when agricultural products are stored improperly, for example, when grain is self-warmed. Under natural conditions, 4 aflatoxins are found: aflatoxins B 1 and B 2 and aflatoxins G 1 and G 2. Among them, aflatoxin B 1 is distinguished by high toxic properties and the most widespread distribution. With the milk of cows consuming feed contaminated with aflatoxins B 1 and B 2, up to 3% of the consumed aflatoxins can be excreted in the form of the corresponding hydroxylated metabolites - aflatoxins M 1 and M 2 . Moreover, aflatoxin M 1 is found both in whole and in powdered milk, and even in dairy products that have undergone technological processing (pasteurization, sterilization, preparation of yoghurts, cottage cheese, cheeses).
Due to the high toxicity and carcinogenicity of aflatoxins and their detection in significant amounts in staple foods, a set of measures is currently being used to detoxify contaminated products. There are mechanical, physical and chemical methods of detoxification. Mechanical methods are associated with the separation of contaminated material manually or with the help of electronic colorimetric sorters. Physical methods are based on a fairly severe heat treatment of the material or are associated with ultraviolet irradiation and ozonation. The chemical method involves the treatment of the material with strong oxidizing agents. Each of these methods has its own significant drawbacks: the use of mechanical and physical methods does not give a high effect, and chemical methods lead to the destruction of not only aflatoxins, but also useful nutrients and, in addition, disrupt absorption. For example, chemical detoxification of feed with ammonia at high pressure and temperature (USA, France) or hydrogen peroxide (India) makes it possible to reduce the content of aflatoxins to a safe level. However, some of the nutritional value of the feed is lost. Biological detoxification of aflatoxins and other mycotoxins by some types of microorganisms is promising.
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Currently, in order to detoxify raw materials, food and feed, a set of measures is used that can be divided into mechanical, physical and chemical methods for detoxifying aflatoxins. Mechanical methods of detoxification are associated with the separation of contaminated raw materials (materials) manually or with the help of electronic colorimetric sorters. Physical methods are based on fairly severe heat treatment of the material (autoclaving), ultraviolet irradiation and ozonation. The chemical method involves the treatment of the material with strong oxidizing agents. Unfortunately, each of these methods has its drawbacks: the use of mechanical and physical methods does not give a high effect, and chemical methods lead to the destruction of not only aflatoxins, but also useful nutrients.
According to WHO data, a person with a favorable hygienic situation consumes up to 0.19 mcg of aflatoxins with a daily diet. In Russia, the following sanitary and hygienic standards for aflatoxins have been adopted: MPC for aflatoxin B 1 for all food products, except milk, is 5 μg / kg, for milk and dairy products - 1 μg / kg (for aflatoxin M 1 - 0.5 μg /kg). Permissible daily dose (ADD) - 0.005-0.01 mcg / kg body weight.
Patulin and some other mycotoxins. Mycotoxins produced by microscopic fungi of the genus Penicillium are ubiquitous and pose a real danger to human health. Patulin is a particularly dangerous mycotoxin with carcinogenic and mutagenic properties.
According to its chemical structure, Patulin is 4-hydroxyfuropyran.
The main products of patulin are the microscopic fungi Penicillium patulum and Penicillium expansu. But other species of this genus of microscopic fungi, as well as Byssochlamys Fulva and Bnivea, are able to synthesize Patulin. The maximum toxin formation differs at a temperature of 21-30 o C.
The biological effect of patulin is manifested both in the form of acute toxins and in the form of pronounced carcinogenic and mutagenic effects. The biochemical mechanisms of action of patulin are not well understood. It is assumed that Patulin blocks the synthesis of DNA, RNA and proteins, and the blocking of transcription initiation is carried out due to the inhibition of DNA-dependent RNA polymerase. In addition, mycotoxin actively interacts with SH-groups of proteins and inhibits the activity of thiol enzymes.
Patulin producers mainly affect fruits and some vegetables, causing them to rot. Patulin is found in apples, pears, apricots, peaches, cherries, grapes, bananas, strawberries, blueberries, blueberries, lingonberries, sea buckthorn, quince, and tomatoes. Apples are most often affected by patulin, where the toxin content can reach up to 17.5 mg / kg. Interestingly, patulin is concentrated mainly in the rotten part of the apple, unlike tomatoes, where it is distributed evenly throughout the tissue.
Patulin is also found in high concentrations in processed fruits and vegetables: juices, compotes, purees and jams. Especially often it is found in apple juice (0.02-0.4 mg / l). The content of patulin in other types of juices: pear, quince, grape, plum, mango - ranges from 0.005 to 4.5 mg/l. Interestingly, citrus fruits and some vegetable crops, as well as potatoes, onions, radishes, radishes, eggplants, cauliflowers, pumpkins, and horseradish, are naturally resistant to patulin-producing fungi.
Among the mycotoxins produced by microscopic fungi of the genus Penicillium and representing a serious danger to human health, it is necessary to single out luteoskirin, cyclochlorotin, citreoviridin, citrinin.
luteoskirin (a product Penicilliumislandicum) - a yellow crystalline substance, isolated from long-stored rice, as well as wheat, soybeans, peanuts, legumes and some types of peppers. The mechanism of toxic action is associated with inhibition of respiratory chain enzymes (liver, kidney, myocardium), as well as suppression of oxidative phosphorylation processes.
Cyclochlorotin (a product Penicilliumislandicum) - a white crystalline substance, a cyclic peptide containing chlorine. Biochemical mechanisms of toxic action are aimed at disrupting hydrocarbon and protein metabolism and are associated with the inhibition of a number of enzymes. In addition, the toxic effect of cyclochlorotin is manifested in the dysregulation of the permeability of biological membranes and the processes of oxidative phosphorylation.
Citreoviridin (productPenicilliumcitreo- viride) - a yellow crystalline substance, isolated from yellowed rice. Has neurotoxic properties.
Citrinin (productPenicilliumcitrine) - a yellow crystalline substance, isolated from yellowed rice. Citrinin is often found in various grains: wheat, barley, oats, rye, as well as corn and peanuts. In addition, trace amounts of citrinin have been found in baked goods, meat products, and fruits. It has pronounced nephrotoxic properties.
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