Mycotoxins are a structurally diverse group of mostly small molecular weight compounds, produced mainly by the secondary metabolism of some filamentous fungi, or molds. These organisms grown under suitable temperature and humidity conditions, and may develop on various foods and feeds, causing serious risks for human and animal health. Mycotoxins have no biochemical significance in fungal growth and development. These compounds are constituted a toxigenically and chemically heterogeneous. They grouped together and can cause disease and death in human, vertebrates, plants, and microorganisms.
Mycotoxins can be toxic depending on the kind of toxins and dose. In animals, acute diseases include liver and kidney damage, attack on central nervous system (CNS), skin diseases and hormonal effects. Among the mycotoxins, aflatoxins produced by Aspergillus flavus, A.parasiticus, A. nomius. Although the potentially harmful effects of feeding moldy grain and foods has been known for many years. While all mycotoxins are of fungal origin, not all toxic compounds produced by fungi are called mycotoxins Human exposure to mycotoxins may result from consumption of plant derived foods that are contaminated with toxins r exposure to air and dust containing toxins. Mycotoxins included aflatoxin which produced by A.flavus, and A. parasiticus, zearalenone and trichothecenes produced by Fusarium spp., ochratoxin produced by A.ochraceus and fumonisins produced by F. moniliforme (. These toxins account for millions of dollars annually in losses worldwide in human health, animal health, and condemned agricultural products.
Factors contributing to the presence or production of mycotoxins in foods or feeds include storage, environmental, and ecological conditions (Moulds may grow on plants in the field or during the storage period. Human food can be contaminated with mycotoxins at various stages in the food chain (Bennett and Klich, 2003) and the most important genera of mycotoxigenic fungi are Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys. Such cases of poisoning may cause death in animals, but are rarely fatal in humans. The toxic effect of mycotoxins on animal and human health is referred to as mycotoxicosis, the severity of which depends on the toxicity of the mycotoxin). Ochratoxin A (OTA) is a secondary metabolite produced by several species of Aspergillus and Penicillium has mainly been found in cereals as well as in other products like coffee, wine, dried fruits, beer and grape juice It occurs in the kidney, liver and blood of farm animals by transfer from animal feed The principal classes of mycotoxins include a metabolite of A. flavus and Aspergillus parasiticus, aflatoxin B1 (AFB1), the most potent hepatocarcinogenic substance known. In dairy cattle, another problem arises from the transformation of AFB1 and AFB2 into hydroxylated metabolites, aflatoxin M1 and M2 (AFM1 and AFM2), which are found in milk and milk products obtained from livestock that have ingested contaminated feed (
Mycotoxins can be classified as hepatotoxins, nephrotoxins, neurotoxins, and immunotoxins Cell biologists put them into generic groups such as teratogens, mutagens, carcinogens, and allergens Risk of mycotoxin contamination in the world is increased due to environmental, agronomic and socioeconomic factors. The socioeconomic and food security status of the majority of inhabitants leave them little option in choosing good quality products. Farmers incur losses due to low productivity of birds and low product quality of ruminants. Consumers end up paying higher end product prices due to increased monitoring at all levels of handling and in extreme cases death problems due to consumption of contaminated products
Mycotoxin contamination can occur pre harvest when the crop plant is growing or postharvest during processing, packaging, distribution, and storage of food products 7,21. The majority of crops and cereals those are stored under fluctuated temperature and suitable humidity for long time can be subject to mold growth and mycotoxin contamination 5. Maize is most the crop susceptible to mycotoxins contamination, while rice is the least 22. Most of mycotoxins have chemical and thermal stability during food processing such as; cooking, boiling, baking, frying, roasting, and pasteurization. Mycotoxins can transfer into the human plate through the animal products including; meat, eggs, milk as the result of the animal eating contaminated feed 3,23. Many national and international public health and governmental authorities such as the US Food and Drug Administration (FDA), World Health Organization (WHO), Food Agriculture Organization (FAO), and the European Food Safety Authority (EFSA), are working in seriuous manner to prevent and control the contamination in food and feed and they addressed this global problem 5.
Aflatoxins are one member of mycotoxins, produced by Aspergillus species such as; A. flavus and A. parasiticus. (. AFs have carcinogenic, teratogenic, hepatotoxic, mutagenic, and immunosuppressive effects, with the liver the main organ affected 5. AFs are associated with both acute toxicity and chronic carcinogenicity in human and animal populations 5. Aflatoxin including four different types of mycotoxins namely; B1, B2, G1, and G2 Aflatoxins are largely associated as contamination for some tropics and subtropics plant products such as cotton, peanuts, spices, pistachios, and maize (Milk can be contaminated with aflatoxin M1 (AFM1) 5, and can be detected in milk 12–24 h after cow consuming feed contaminated with AFB129. AFM1 is heat stable and it can binds well to casein, thus it can be detected cheese with a concentration higher than that of the raw milk 30,31. In Africa and developing countries the acute toxicosis are usually rare whereas chronic carcinogenicity is a global problem 5,32. The symptoms of the acute aflatoxicosis is characterized by vomiting, abdominal pain, pulmonary and cerebral edema, coma, convulsions, and even death 34. Due to the extreme the FDA since 1969 paid a huge concerns for preventing the great effects of AF contamination in food and feed.