Mycotoxins .....What are they?

Mycotoxins What are they? Mouldy coffee beans Mycotoxins1 are naturally occurring chemical compounds produced by certain fungi that pose a threat to humans and animals when ingested. Fungi, like all heterotrophic organisms, need water and certain essential nutrients in order to live. Food crops represent a good source of nutrients for such moulds. As the moulds grow on these food commodities, they produce secondary metabolites, which include mycotoxins. Each mycotoxin is produced by one or more very specific fungal species, and in some cases one species can form more than one mycotoxin (see table below). However, the prescence of a recognised toxin-producing fungus does not automatically imply the presence of the associated toxin as many variables are involved in mycotoxin formation. Conversely, the lack of visible mould is not a guarantee that the foodstuff is free from toxins as the mould may have already died, leaving the toxin intact. The moulds and mycotoxins that are considered to be of major public health and economic significance worldwide are listed in the table below: Mould species Mycotoxins Occurrence Aspergillus parasiticus Aflatoxins B1, B2, G1, G2 Maize (corn), groundnuts (peanuts), tree nuts, spices, dried fruit, crude vegetable oils, cottonseed and copra Aspergillus flavus Aflatoxins B1, B2 Fusarium sporotrichiodes T-2 toxin Cereals Fusarium graminearum Deoxynivalenol (DON) Grains, especially wheat, barley, oats, rye and maize. Less often in rice and sorghum Fusarium graminearum Zearalenone Maize, but also lower levels in rice, wheat, barley, malt and soybean Fusarium moniliforme Fumonisin B1 Maize Penicillium verrucosum Ochratoxin A (OTA) Cereals, fresh grapes, dried vine fruit, wine, beer, coffee, cocoa Aspergillus ochraceus Ochratoxin A (OTA) Penicillium expansum Patulin Fresh and processed fruit and vegetables (especially apples) (see FAO, Food and Nutrition Papers 73, 'Manual on the application of the HACCP system in mycotoxin prevention and control', 2001) 1 The term 'mycotoxin' combines the Greek word for fungus ('mykes') and the Latin word for poison ('toxicum'). Pitt (1996) defined mycotoxins as "...fungal metabolites which, when ingested, inhaled or absorbed through the skin cause lowered performance, sickness or death in man or animals, including birds".