Foods are full of natural chemicals essential to our health, but some foods contain potentially harmful substances called natural toxins. Most natural toxins are found naturally in some foods and other natural toxins are produced. when the food is damaged or when mold or fungus grows on the food,First natural toxins produced by fungi: example of mycotoxins.MycotoxinsMycotoxins are metabolites of mold that can infect food, feed and which are toxic to humans. The study of mycotoxins and the legislation associated with their control is based on the fact that they are considered adulterants of food and feed. Huge quantities of food are wasted every year and are attacked by toxic fungi or contaminated by fungal metabolic products. This waste occurs more significantly in warmer countries, where food shortages can already be a problem. According to one estimate (CAST, 2003), mycotoxins affect a quarter of the world's food crops, including many staple foods and feeds as well as crops. Mycotoxins are toxic chemicals formed by fungi that can grow on crops in the field or after harvest and in foods that may be affected, including grains, nuts and dried fruits; coffee coconut spices oilseeds and milk Some mycotoxins such as aflatoxins are among the most potent mutagens and carcinogens known (CAST, 2003). Mycotoxins are associated with many chronic health risks, including cancer induction, immune suppression, blood digestive disorders, and nerve abnormalities (CAST, 2003, Shepherd, 2006). There are now over 300 known mycotoxins with very different chemical structure and chemistry. different modes of action and some target the kidneys, liver and immune system. Common mycotoxins include aflatoxins, ochratoxin A, alkaloids, fumonisins, and patulin. Mycotoxins are toxic secondary metabolites of fungi that generally belong to one of three genera1] Aspergillus species, 2] Penicillium 3] Fusarium Aspergillus species: Aflatoxins: Aspergillus specious occurs in foods as spoilage. There is. They are very common in stored food products such as grains, nuts and nuts, more frequently in tropical and subtropical climates than in moderate climates. Mycotoxins were brought to the attention of scientists in the 1960s with the outbreak of turkey disease X that killed nearly 100,000 turkeys and other farm animals in England. The origin of the illness was traced to the peanut flour contained in the food which was heavily contaminated with A. flavus. An analysis recently revealed that a group of fluorescent compounds were responsible for the outbreak and were named aflatoxins..