Mycotoxins in cereals and cereal products: occurrence and changes during processing

Over a period of 4 years (2000-2003), wheat and rye samples of integrated and ecological cultivation in the Federal State of Brandenburg were analyzed by HPLC as to the Fusarium toxins deoxynivalenol and zearalenone. In the years 2000, 2001 and 2003, the contamination generally was lower than in the year 2002. In the 4 years of testing, the contamination by Fusarium toxins was significantly seldomer and lower in cereals of ecological cultivation than in cereals of integrated cultivation. In all the years rye samples showed a lower contamination by the Fusarium toxins than wheat samples. 1993 and 1994 cereals and maize (cultivated in the Federal Republic of Germany) were analyzed by HPLC to fumonisins, a group of other Fusarium toxins. In wheat and rye as well as in oats and barley no fumonisins were detectable. In indigenous maize, fumonisins were detected in different frequency and concentration (mean value of the positive samples approx. 200 μg/kg). During hydrothermal treatment of maize a decrease of fumonisin content was observed. Cooking extrusion (180-220 °C) and gelatinization (80-120 °C) reduced fumonisin levels to approx. 30-55 %, cooking the grits for flaking (30-90 min., 130 °C) to approx. 20-65 %, and roasting the flakes (2.5 and 5 min., 250 °C) to approx. 6-35 % (in dependence on the selected technological parameters in the laboratory trials). Until now it was not possible to clarify, to which extent the decrease of the measurable fumonisin content is connected with detoxification.