Abstract: The factors affecting the content of vomitoxin (deoxynivalenol, DON), in wheat were analyzed, and the contamination characteristics and distribution difference of vomitoxin in different types of wheat grains and different grain parts were evaluated. The results showed that disease infection, injury, the size of wheat grains, and the type of insect injury affected vomitoxin contamination. Vomitoxin content was weakly positively correlated the percentage of perfect grains, but significantly positively correlated with the percentage of gibberella-damaged grains. Significant differences in the level of vomitoxin contamination were found among different grain types and different parts of the same cultivar; the content of vomitoxin was significantly higher in gibberella-damaged grains than in the uninfected ones, in broken grains than in the intact ones, in small grains than that in the large ones, and in the embryo than that in the endosperm. The content of vomitoxin in the kernel surface accounted for 35.2%–52.1% of the total. More serious vomitoxin contamination was observed in the part closer to the outer layer of the endosperm, while less serious vomitoxin contamination appeared in the part closer to the center of the kernel center. After wheat flouring, the content of vomitoxin was higher in the bran but lower in the flour. Vomitoxin contamination in wheat can be effectively reduced by grading, sorting, washing and milling.

Key words: wheat; grain; vomitoxin; contamination characteristics