Fusarium spp. and Fusarium mycotoxins in maize: a problem for Flanders?

Fusarium species cause not only root, stem and ear rot with severe reductions in crop yield, they produce also toxic secondary metabolites (mycotoxins) such as deoxynivalenol (DON) and zearalenone (ZEA). During several growing seasons the presence of Fusarium spp was followed up. DON and ZEA were determined and related to infection levels. The distribution of DON and ZEA in the different plant parts was studied as well as the influence of the ensiling process on the mycotoxin content. More or less important varietal differences in susceptibility for Fusarium spp. could be detected. DON and ZEA were clearly present in most of the analysed samples. No clear relationship could be detected between visual disease symptoms and mycotoxin content. The accumulation of DON and ZEA was different for the analysed aerial plant parts. The ensiling process gave no reduction of the mycotoxin content.

Differences in susceptibility of winter wheat varieties for Fusarium species under Belgian growing conditions.

Fusarium head blight is an important disease of cereal crops caused by Fusarium species. It causes not only a reduction in yield, but most Fusarium species (F. graminearum. F. culmorum, F. avenaceum. F. poae) produce also a range of toxic metabolites such as deoxynivalenol (DON) and zearalenone (ZEA). The evaluation of Fusarium species was followed up under natural infection conditions during the growing seasons 2001--2002 and 2002--2003 in two varietal winter wheat experiments on the experimental farm of the Hogeschool Gent at Bottelare. Disease pressure, DON and ZEA content, different Fusarium species as well as growth and yield parameters were determined. In both years there were significant differences between the varieties concerning the susceptibility to Fusarium and the DON content. ZEA was not found in the kernels. The mean deoxynivalenol (DON) content was in 2002 (1,126 mg/kg) higher than in 2003 (0.879 mg/kg) although the mean disease severity was bigger in 2003 than in 2002 what means that the DON content was not always correlated with the disease severity. The Fusarium species most frequently identified in our two field trials (Bottelare) were F. graminearum and F. culmorum Varietal differences in susceptibility to Fusarium species and DON contamination could be detected.

Development and validation of an LC-MS/MS method for the simultaneous determination of deoxynivalenol, zearalenone, T-2-toxin and some masked metabolites in different cereals and cereal-derived food.

An LC-MS/MS method was developed and validated for the simultaneous determination of deoxynivalenol, zearalenone, T-2-toxin, HT-2-toxin and metabolites, including 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, deoxynivalenol-3-glucoside, α-zearalenol, ß-zearalenol, zearalenone-4-glucoside, α-zearalenol-4-glucoside, ß-zearalenol-4-glucoside and zearalenone-4-sulfate in maize, wheat, oats, cornflakes and bread. Extraction was performed with acetonitrile/water/acetic acid (79/20/1, v/v/v) followed by a hexane defatting step. After filtration, the extract was evaporated and the residue was redissolved in mobile phase for injection. The mobile phase, which consisted of a mixture of methanol and water with 10 mM ammonium acetate, was adjusted to pH 3 with glacial acetic acid. A sample clean-up procedure was not included because of the low recoveries of free and masked mycotoxins and their differences in polarity. The method allowed the simultaneous determination of 13 Fusarium mycotoxins in a one-step chromatographic run using a Waters Acquity UPLC system coupled to a Quattro Premier XE mass spectrometer. The method was validated for several parameters such as linearity, apparent recovery, limit of detection, limit of quantification, precision, expanded measurement uncertainty and specificity. The limits of detection varied from 5 to 13 ng g⁻¹; those for the limit of quantification from 10 to 26 ng g⁻¹. The results of the performance characteristics of the developed LC-MS/MS method were in good agreement with the criteria mentioned in Commission Regulation (EC) No. 401/2006. Thirty samples of a variety of food and feed matrices were sampled and analysed between July 2010 and January 2011.