Increase of Deoxynivalenol during the malting of naturally Fusarium infected Chinese winter wheat

Wheat constitutes a significant adjunct ingredient for beer brewing in China, but is prone to be contaminated with Deoxynivalenol (DON). To evaluate the development of DON and its producing-Fusariums in the malting, thirteen Chinese winter wheat samples of natural DON levels under the national standard limit (1000 μg/kg) were selected to malt in lab-scale. DON levels increased in the malting for all samples by 282% on average, and exceeded of 1000 μg/kg in 7 malts. Fate of DON and Fusariums in the malting was monitored for three samples with the relatively large increase of DON levels. Around 95% of initial wheat DON was washed away by steeping, but the DON level rose up to 7-fold in the following germination, which was caused by the growth of Fusariums with tri5 DNA level increasing by 28-fold averagely. Fifty-one percent of tri5 DNA in the germinated wheat was terminally denatured by high temperature in the kilning stage, but DON survived. About 26% of DON was get rid by de-rooting. The result highlighted the risk of DON increase in the malting of Fusarium Height Blight wheat.