Occurrence, importance and control of mycotoxins: A review

Mycotoxins are poisonous chemical compounds produced by certain fungi. There are five mycotoxins or groups of mycotoxins that occur quite often in food: deoxynivalenol/Nivalenol, zearalenone, ochratoxin, fumonisins and aflatoxins. The fungi that produce mycotoxins in food fall broadly into two groups: those that invade before harvest, commonly called field fungi, and those that occur only after harvest, called storage fungi. There are three types of toxicogenic field fungi: plant pathogens such as  Fusarium graminearum (deoxynivalenol, nivalenol); fungi that grow on senescent or stressed plants, such as Fusarium moniliforme (fumonisin) and sometimes Aspergillus flavus (aflatoxin); and fungi that initially colonize the plant before harvest and predispose the commodity to mycotoxin contamination after harvest, such as Penicillium verrucosum (ochratoxin) and A. flavus (aflatoxin). The favourable conditions for mycotoxins production are instigated with poor hygienic conditions at the time of transportation and storage, high temperature and moisture content and heavy rains. Mycotoxins are distributed in different items such as animal feeds, cereal crops, leguminous plants and animal products. Concentrated animal feed stuffs harbour highest level of mycotoxins. Noug cake and sorghum was warranted as the main source of aflatoxin contaminant among those concentrated animal feeds. Health effects occur in companion animals, livestock, poultry and humans because aflatoxins are potent hepatotoxins, immunosuppressant, and mutagens and carcinogens. Factors that affect mycotoxins production and contamination can be categorized as physical, chemical and biological. Therefore, African countries particularly Ethiopian governmental jurisdictions shouldimplement and regulate level of mycotoxins in animal feed stuffs and human foods.