The current article describes the evaporation behaviour of dimethyl sulfide (DMS) in wort. All thermodynamic and technological basics and DMS data are listed. However, the article's target was not just the collection, editing and reviewing of information but also how to predict DMS evaporation behaviour from wort for different temperatures based on the data in the literature. For that particular purpose, a function was first set up that combined all of the information available on evaporation behaviour. In this context, the so‐called activity coefficient (γi) is of crucial interest. Owing to the broad basis of literature evaluated, the function set‐up as described can be deemed to be a current and accurate tool for predicting DMS evaporation behaviour, in general, as well as in particular for different boiling systems. Copyright © 2016 The Institute of Brewing & Distilling

During malt kilning, significant amounts of dimethyl sulfide (DMS) oxidize leading to the formation of dimethyl sulfoxide (DMSO), a precursor of DMS during fermentation. Yet, knowledge regarding reaction mechanisms of DMSO formation during malt production is limited. The role of thiols in sulfide oxidation is unclear as they possess sulfoxide reducing ability as well as pro- and antioxidative properties. This study investigated the effects of the thiol l-cysteine (Cys), molecular oxygen, transition metal ions, and EDTA on DMS oxidation in aqueous model solutions. Highest oxidative DMS consumption was observed when Cys was combined with iron(II) (∼12%) and copper(II) (∼40%). Response surface modeling (RSM) revealed that Cys together with copper(II) had a strictly prooxidative effect and no antioxidative behavior was found. Hydrogen peroxide, as generated via autoxidation of Cys-Cu(I)-Cys complexes, was supposed to be the primary DMS oxidant in this work. Based on redox kinetics, potential reaction mechanisms, and their impact on oxidative processes in thermal food processing, such as malt and beer production, are discussed.

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