Fusarium moulds are widespread on growing crops and normally do little damage to the plant. However, under some conditions they can produce a number of toxins from the trichothecene group, including deoxynivalenol (DON), nivalenol (NIV), T-2 and HT-2, as well as zearalenone (ZEA). Since March 2007, maximum limits for DON and ZEA in cereals have been operated in the EU. For DON these are at 1250µg/kg in raw cereals and 750µg/kg for processed cereals (which includes malt); for ZEA these are 100µg/kg and 75µg/kg respectively.
The European Commission are collating data on T-2 and HT-2 in a three-year project to understand further their occurrence in crops and diet. MAGB is contributing malting barley data to this survey. No maximum limit is in force for these mycotoxins.
The levels of Fusarium toxins in malt can be controlled by good farming practices producing good quality barley, then by grain inspection at intake from farm, by efficient drying and good storage conditions (for both malt and barley) and by attention to hygiene in the malting plant.
Results of tests on UK grown malting barley purchased by UK maltsters in crop years from 2015 to 2019 are shown in the charts below: