FERMENTATION OF WORT CONTAINING ADDED OCHRATOXIN-A AND FUMONISIN-B-1 AND B-2

Ochratoxin A (OA), fumonisin B-1 (FB1) and fumonisin B-2 (FB2) were ad ded to wort at levels of 0.19, 0.95 and 0.95 mu g/ml, respectively, an d fermented for up to 8 days by three strains of Saccharomyces cerevis iae. Decreases of OA in the beer over this period were estimated from straight line slopes to be 2-13%. Losses of FB1 and FB2 were estimated to be 3-28% and 9-17% respectively. Some OA was taken up by the yeast , up to 21% in a detailed study with one strain. In contrast, uptake o f fumonisins by yeast was negligible (< 1% FB1 and < 2% FB2). In contr ol experiments, OA, FB1 and FB2 were found to be stable when added to yeast-free wort and kept for up to 8 days at 25 degrees C. In addition , spiking experiments with blank day 0-8 fermenting wort samples showe d method recoveries averaging 87-91%. None of the mycotoxins was detec ted in control fermentations where they were not added to the wort.