The fate of deoxynivalenol and fumonisins in wheat and maize during commercial breakfast cereal production

Abstract

A study of the changes undergone by Fusarium mycotoxins present in maize and wheat at intake during the processing of commercial grain samples into breakfast cereals was carried out. Natural concentrations of deoxynivalenol and zearalenone in wheat were mostly low although higher levels of fumonisins occurred in maize. An exhaustive cleaning regime was used for wheat received from UK farms that reduced deoxynivalenol levels by about 50%, although this varied considerably between consignments. During processing to manufacture two commercial breakfast cereals, further loss of deoxynivalenol was minimal. However, this was significantly greater in a product from which excess aqueous cooker effluent was drained, suggesting that loss was due to solution of the mycotoxin in the cooking liquor rather than to hydrolysis. It is estimated that deoxynivalenol present at the EC maximum limit of 1,250 µg/kg in intake wheat would be reduced to about 700 and 400 µg/kg respectively for the 2 types of whole-wheat breakfast cereals examined during processing. Maize flaking grits were inherently low in mycotoxin concentrations compared to the raw maize so that the mycotoxin levels in the cereal ingredient for cornflakes used in this manufacturing process were unlikely to approach EC regulatory levels. In processing these grits, fumonisins were reduced further by at least 93% although no reduction of deoxynivalenol occurred. It is estimated that fumonisins and deoxynivalenol at the EC maximum limits in raw maize of 4,000 µg/kg and 1,750 µg/kg would be reduced to about 17 µg/kg and 288 µg/kg respectively in corn flakes made by the traditional cooking process used in the UK.