The cereal food chain covers events from the sowing of the seed until the point of ingestion of a food by the consumer. Mycotoxins may develop prior to harvest or through inadequate storage. Most mycotoxins are inherently stable natural chemicals but cleaning, milling and different methods of processing can change their concentrations. Legislation is necessary to protect the consumer so it is important to consider, among other things, the relationship between concentrations of mycotoxins in the raw grains and those in the product purchased by the consumer, especially where different limits are specified at successive stages in manufacture. Recent studies of the fate of fusarium mycotoxins in the cereal food chain carried out alongside industry in the UK have examined changes in the concentrations of deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin and zearalenone in wheat, maize and oats and the fumonisin mycotoxins in maize at key stages in the cereal chain. For example, fumonisin concentrations in maize grits after milling were reduced by about 75% compared with the raw maize, but remained similar to the maize in the flour and were increased (*3 to *5) in the bran and meal. Maize flour and grits were then processed into a range of food products such as breakfast cereals, cornflakes, extruded snack products and tortillas and the changes in concentrations were established. Simple extrusion of flour or grits reduced fumonisins by a further 30-70% depending on the process. Deoxynivalenol and zearalenone were found to be more stable than fumonisins during most processes.
