Transfer ofFusariummycotoxins and ‘masked’ deoxynivalenol (deoxynivalenol-3-glucoside) from field barley through malt to beer

Abstract

The fate of five Fusarium toxins--deoxynivalenol (DON), sum of 15- and 3-acetyl-deoxynivalenol (ADONs), HT-2 toxin (HT-2) representing the main trichothecenes and zearalenone (ZON) during the malting and brewing processes--was investigated. In addition to these 'free' mycotoxins, the occurrence of deoxynivalenol-3-glucoside (DON-3-Glc) was monitored for the first time in a beer production chain (currently, only DON and ZON are regulated). Two batches of barley, naturally infected and artificially inoculated with Fusarium spp. during the time of flowering, were used as a raw material for processing experiments. A highly sensitive procedure employing high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was validated for the analysis of 'free' Fusarium mycotoxins and DON-conjugate in all types of matrices. The method was also able to detect nivalenol (NIV), fusarenon-X (FUS-X) and T-2 toxin (T-2); nevertheless, none of these toxins was found in any of the samples. While steeping of barley grains (the first step in the malting process) apparently reduced Fusarium mycotoxin levels to below their quantification limits (5-10 microg kg(-1)), their successive accumulation occurred during germination. In malt, the content of monitored mycotoxins was higher compared with the original barley. The most significant increase was found for DON-3-Glc. During the brewing process, significant further increases in levels occurred. Concentrations of this 'masked' DON in final beers exceeded 'free' DON, while in malt grists this trichothecene was the most abundant, with the DON/DON-3-Glc ratio being approximately 5:1 in both sample series. When calculating mass balance, no significant changes were observed during brewing for ADONs. The content of DON and ZON slightly decreased by a maximum of 30%. Only traces of HT-2 were detected in some processing intermediates (wort after trub removal and green beer).

Advanced LC–MS-based methods to study the co-occurrence and metabolization of multiple mycotoxins in cereals and cereal-based food

“…Currently, this technique is being used during baking on an industrial scale to reveal the formation of degradation products of mycotoxins. Moreover, such tracer-fade studies could also be used for elucidation of elevated levels of masked mycotoxins found during malting and brewing [93,94].…”

Human exposure to mycotoxins and their masked forms through cereal-based foods in Belgium

“…Furthermore, in these matrices co-occurrence of masked and parent mycotoxins has been previously described (De Boevre et al, 2012a;Berthiller et al, 2009b;Desmarchelier & Seefelder, 2011;He et al, 2010;Kostelanska et al, 2009;Lancova et al, 2008;Vendl et al, 2010). To date however, no risk assessments were performed for masked mycotoxins.…”

Monitoring of the occurrence of deoxynivalenol in beers from outlet shops in 2009-2012.

“…Výměna máčecí vody sice odstraňuje část mykotoxinů, ale při klíčení může docházet opět k jejich nárůstu . Při hvozdění dochází k poklesu obsahu mykotoxinů, ale ne k jejich vymizení (Laitila, 2007;Oliveira, et al ., 2012;Lancová, et al ., 2008) . Plísně a jejich spóry se z infikovaného ječmene a sladu do piva dostat nemohou, nejpozději ve stádiu chmelovaru jsou usmrceny .…”

“…Exchange of steeping water removes part of mycotoxins, but they can start to grow again during germination . During kilning, mycotoxins are reduced but not eliminated (Laitila, 2007;Oliveira et al ., 2012;Lancová et al ., 2008) . Fungi and their spores cannot pass from infected barley and malt into beer; they are killed in the phase of wort boiling as the latest .…”