Photocatalytic decomposition of aflatoxins and deoxynivalenol in barley steeping for beer production

Abstract Aflatoxins (AFs) and deoxynivalenol (DON), common mycotoxins in cereals, pose contamination risks in beer production, often persisting from raw barley into final products. This study investigates the transfer and decomposition of AFs and DON during the barley steeping stage of malting. Barley spiked with AFs and DON was steeped, and mycotoxin concentrations were analyzed in both the barley residue and the resulting wastewater. Results indicated that AF and DON transfer into wastewater was influenced by water solubility, though concentrations remained below solubility limits. AFs and DON residues were also detected in the steeped barley. Decomposition studies showed that while AFs were partially degraded by UV light, DON required photocatalysis for effective degradation. However, matrix components in wastewater decreased the efficiency of DON decomposition, suggesting that preliminary removal of organic components from wastewater could enhance photocatalytic detoxification. These findings provide insight into mycotoxin management strategies for brewing wastewater, emphasizing the need for targeted pretreatment to improve degradation efficiency.