Fate of the mycotoxins in the wort and yeast during ale and lager fermentation and their evaluation under different technological parameters

This study aimed to evaluate the mycotoxins transfer in the wort and yeast during ale and lager fermentation, secondary fermentation, and beer storage. Four yeasts were used to ferment wort contaminated with DON and ZEN. The wort was fermented with two S. cerevisiae yeasts (yeasts A and B) at 15, 20, 25 °C for 96 h, and two S. pastorianus (yeasts C and D) at 10, 15, 20 °C for 144 h. After fermentation, the two wort with the highest mycotoxin decrease were selected for a second fermentation and stored period. Mycotoxins were extracted using QuEChERS and analyzed by UHPLC-DAD/FLD. In the wort, DON decreased from 11% to 27%, locating it adsorbed on the yeast from LOD to 6.16%. ZEN in the wort decreased from 29% to 90%, locating it adsorbed on the yeast from 5.41% to 33.86%. Ale-fermentation process obtained the highest decrease of ZEN in the wort, whereas, for DON, there was no significant difference in the reduction between the 2 fermentation styles. Finally, there was no significant change in mycotoxin content during storage. Knowledge of the mitigating effect of fermentation variables could help to reduce the mycotoxin content in beer. The authors are grateful to the University of Lleida (grant JADE Plus 218/2016), and to the Spanish Ministry of Economy and Competitiveness (MINECO, Project AGL2017-87755-R) for funding this work. Wall-Martínez HA is grateful to the Consejo Nacional de Ciencia y Tecnología (CONACyT) of Mexico for the scholarship.