Early Detection of Deoxynivalenol in Wheat Grain

The cereals crops in Belgium are not safe from serious contaminations by mycotoxins. Theyears 1997 and 1998 for example were very favourable to the development of Fusariumhead blight. On that account, the project main objective consists in assessing the risk ofmycotoxins contamination and studying the environmental factors that contribute to increasethe rate of wheat contamination and integrating them in a forecasting model. A competitivedirect enzyme-linked immunosorbent assay (CD-ELISA) for the semi-quantitative analysisof deoxynivalenol (DON) has been used on 130 samples of wheat grains of the harvest2000. In addition, a HPLC multi-residue method is in development to separate variousmycotoxins. Samples, mentioned above, were contaminated mainly byMicrodochium nivale(96%), a fungi inducing scab symptoms but not suspected to produce mycotoxins, F.culmorum (22%) and F. graminearum (15 %). A small amount of analyzed samples werecontaminated by F. poae and F. avenaceum. PCR analyzes were used to verify theFusarium species microscopic identification. The DON concentration determined by immu-nological analysis has provided values ranging from 0 to 1,2 ppm (92%: 0-0,5 ppm; 6%: 0,6-1 ppm; 2% > 1 ppm). In the other hand, two types of artificial contaminated field trials wereestablished: 1) A multi-variety trial where different varieties of wheat were inoculated sepa-rately withF. graminearum and F. culmorum. 2) A one-variety trial where 20 Fusarium strainsbelonging to the four Fusarium species, above mentioned, were inoculated. For the first trial,we observed differences in both infection rates in the field and DON accumulation betweenvarieties but not betweenFusarium species inoculated. For the second one, differences inDON production were observed between Fusarium species and between some strains ofthe same species. Microbiological analyses and field observations show a good correlationbut they were not related to the DON concentration. 2001 National Fusarium Head Blight Forum 169Food Safety, Toxicology and UtilizationPHYSICAL TREATMENTS FOR PREVENTING THE POST-HARVESTGROWTH OF FUSARIUM IN MALTING BARLEY B. Kottapalli and C.E. Wolf-Hall* Department of Cereal and Food Sciences, North Dakota State University, Fargo ND*Corresponding Author: PH: (701) 231-6387; E-mail: [email protected]