3-Methylthiopropionaldehyde as Precursor of Dimethyl Trisulfide in Aged Beers

Abstract

Hop S-methylcysteine sulfoxide has previously been postulated as the precursor of dimethyl trisulfide (DMTS) in beers. The present data point to 3-methylthiopropionaldehyde, the Strecker aldehyde issued from methionine, as another potential precursor in aged beers. Spiking either fresh beer or wort before boiling leads in all cases to higher levels of DMTS after storage. Moreover, special malts with a high level of 3-methylthiopropionaldehyde also favor polysulfide synthesis. A higher pH should increase this onion-like off-flavor, whereas a low pH is unfortunately known to enhance the cardboard flavor of aged beers. 3-methylthiopropanol, issued from yeast reducing activity, can be considered as an additional DMTS source during aging.

Identification and origin of the character‐impact compounds of raw oyster Crassostrea gigas

“…3-Methylthio-1-propanol could be a reduction compound of methional. 23 Ethylpyrazine, which had a high odour detection threshold of 6000-22 000 ppb, 21 was present in small quantity in oyster extract (0.8 ng equivalents 3-hexanone g À1 dry matter of oyster; Table 2). Its high detection threshold could explain why it was detected by only three judges.…”

Quantification of key odor-active compounds of a novel nonalcoholic beverage produced by fermentation of wort by shiitake (Lentinula edodes) and aroma genesis studies

“…In wort and beer, these compounds are derived from Maillard type reactions (Coghe, Martens, D'Hollander, Dirinck, & Delvaux, 2004;Osamu, Takeo, Yutaka, & Motoo, 2006), oxidation of carotenoids (Bezman et al, 2005;De Schutter et al, 2008b), Strecker degradation (Gijs, Perpète, Timmermans, & Collin, 2000;Soares da Costa et al, 2004), and degradation of tryptophan (Gijs, Chevance, Jerkovic, & Collin, 2002). Their concentrations decreased with increasing fermentation time (Fig.…”

“…β-Damascenone may be reduced and/or adsorbed rapidly by yeast as well (Chevance, Guyot-Declerck, Dupont, & Collin, 2002). Methional, as an important odorant of wort, is derived from the amino-carbonyl reaction and the following Strecker degradation of L-methionine during the processes of wort boiling and wort clarification (Gijs et al, 2000;Soares da Costa et al, 2004). Methional has been described to impart the wort-like off-flavor of alcohol-free beer (Perpète & Collin, 1999).…”

Production and characterization of alcohol-free beer by membrane process

“…Acetaldehyde amount in the original beer was about 56 mg/L and decreased after dealcoholization of 93% (Table 2). Among aldehyde compounds, Strecker aldehydes, 2-methylbutanal (threshold=1.25 mg/L), 3-methylbutanal (threshold=0.6 mg/L), methional (threshold=0.25 mg/L) and phenylacetaldehyde (threshold=1.6 mg/L) are important constituents contributing to the "aged" flavour of beer (Gijs et al, 2000). The concentration of these compounds was lower than their taste threshold as indicated in Table 3.…”