Fate of ochratoxin A and citrinin during malting and brewing experiments.

The fate of ochratoxin A and citrinin during malting and brewing processes was studied by the use of naturally contaminated lots of barley, as well as by the addition of crystalline toxins to the mash. Complete degradation was observed for ochratoxin A from moderately contaminated barley lots and for citrinin added to mash. The use of highly contaminated barley resulted in transmission of ochratoxin A into the beer, but only 2 to 7% of the initial content was detected, corresponding to levels of 6 to 20 mug of ochratoxin A per liter of beer. Barley lots with this high ochratoxin contamination (1,000 to 5,000 mug/kg) will be easily detected and, therefore, because of pronounced deterioration, should be rejected during inspection upon admittance to the breweries.