Polyfunctional thiol compounds

Abstract

Sulfur compounds, and especially volatile thiols, are extremely odoriferous molecules, which contribute to the aromas of many fruits, plants, and foods (Shankaranarayana et al. 1982). For example, certain thiols contribute to the characteristic aroma of blackcurrant (Rigaud et al. 1986), grapefruit (Demole et al. 1982; Buettner and Schieberle 1999), passion fruit (Engel and Tressl 1991), guava (Idstein and Schreier 1985), and fringed rue (Ruta chalepensis) (Escher et al. 2006). The key role played by thiols in the odor of roasted coffee (Tressl and Silwar 1981), popcorn, and grilledmeat is also well known (Gasser and Grosch 1988;Guth and Grosch 1994; Schieberle 1991). Finally, the contribution of compounds in this family to the aroma of beer was recently reported (Vermeulen et al. 2006; Takoi et al. 2007). In wine, sulfur compounds (including thiols) were initially exclusively associated with fetid, nauseating odors, mainly due to molecules such as hydrogen sulfide, methanethiol, ethanethiol, and methionol. The involvement of sulfur compounds in the pleasant herbaceous, fruity, mineral, smoky, and toasty aromas of wine was only detected at a later stage, thanks to a specific method for purifying volatile thiols, using p-hydroxymercuribenzoic acid (p-HMB) (Tominaga et al. 1998a; Tominaga and Dubourdieu 2006). © Springer Science+Business Media, LLC 2009.