Use of Sodium Bisulfite as a Method to Reduce DON Levels in Barley during Malting

This is the authors' abstract. We don't add key points for this paper.

Barley infected with fungi such as Fusarium spp. in certain geographic regions of the world can result in grain contaminated with toxins such as deoxynivalenol (DON), nivalenol, and zearalenol. In some regions, crops are becoming more commonly contaminated with DON, a toxin that if consumed in sufficient quantities may lead to ill effects in both livestock and humans. Some concern exists in the brewing and malting industries when using DON-contaminated barley because correlations have been made between Fusarium infections in malt and negative events such as premature yeast flocculation and gushing. Also, several reports have shown that low levels of DON toxins can carry through to final beer products. Good agricultural and malting practices reject contaminated grain before intake; however, further protective treatments during malting can provide added protection to ensure low levels of DON in beer. Sodium bisulfite treatments (10, 50, 80, and 200 g/L) were applied to barley prior to micromalting to determine its ability to remove DON. Based on an initial screening, the treatment that removed the most DON without hampering germination was selected for further testing and brewing evaluation. Sodium bisulfite gave a 93% reduction in DON levels, whereas nontreated samples showed an 86% decrease in DON levels during malting. Leaching of the water-soluble toxin during malting was suspected; however, further reductions in DON levels with sodium bisulfite treatments suggest that leaching is not the only mechanism by which DON is reduced in malting. The quality of the sodium bisulfite-treated malts was not altered. Fermentations of treated malt indicated adequate malt performance with no indication of premature yeast flocculation.