Involvement of Dimethyl Sulfide and Several Polyfunctional Thiols in the Aromatic Expression of the Aging Bouquet of Red Bordeaux Wines

Abstract

The development of an aromatic bouquet during fine wine aging depends on complex transformations occurring in a reductive atmosphere, favorable to the formation and preservation of sulfur odorants, such as dimethyl sulfide (DMS) and polyfunctional thiols. The aim of this study was to address their role in the occurrence, evolution, and perceived sensory nuances of the aging bouquet of red Bordeaux wines. These compounds were quantified in 24 wines and scored by a professional wine panel for the degree to which they reflected the aging bouquet olfactory concept. Partial least square (PLS) analysis, combining sensory and quantitative chemical data, predicted that DMS, 2-furanmethanethiol, and 3-sulfanylhexanol concentrations correlated with the typicality score, discriminating highly-typical wines from less-typical ones. Several vintages from three vineyards were then subjected to sensory and chemical analysis to determine how aging bouquet typicality and the intensity of five key aromatic notes (undergrowth, truffle, fresh fruit, toasted, and empyreumatic) evolved during bottle storage in relation to these three sulfur odorants. PCA analysis emphasized their combined impact on aging bouquet typicality and their contribution to undergrowth, truffle, and empyreumatic attributes.

Vine Water Deficit Impacts Aging Bouquet in Fine Red Bordeaux Wine

“…Previous published data had not detected strict correlations between aging and bouquet typicality scores and wine age, although a vintage effect was highlighted (Picard et al, 2015b ). As vintage quality is closely determined by the climatic conditions during vine development and grape ripening, particularly vine water status (van Leeuwen et al, 2009 ; van Leeuwen and Darriet, 2016 ), we hypothesized a potential impact of vine water deficit on aging bouquet development during bottle storage.…”

“…The sensory performance of the two panels was assessed and confirmed by their ability to reproduce the same classification of two sets of five wines perceived as either good or poor examples of the wine aging bouquet typicality over a 10 months period (Picard et al, 2015a , b ).…”

“…Recently, major advances have been made toward elucidating this complex olfactory concept, both from sensory and molecular perspectives. Specific aromatic properties (Picard et al, 2015a ), as well as the contribution of several chemical markers (Picard et al, 2015b , 2016a ), have been identified.…”

“…It focused particularly on undergrowth, truffle, and mint notes, since their chemical composition had already been partly deciphered. Indeed, the direct contribution of dimethyl sulfide (DMS) to truffle and undergrowth attributes, as well as the overall complexity and balance of wine has been widely reported (Du Plessis and Loubser, 1974 ; Spedding and Raut, 1982 ; Segurel et al, 2004 ; Picard et al, 2015b ). Moreover, it has already been shown that the potential of DMS (PDMS), susceptible to be chemically released by S -methyl methionine degradation (Segurel et al, 2004 ; Loscos et al, 2008 ) is dependent upon numerous terroir factors, including vine water status, grape maturity at harvest, and the yeast assimilable nitrogen content of must (Bell and Henschke, 2005 ; Dagan, 2006 ; Dagan and Schneider, 2012 ; De Royer Duprè et al, 2014 ).…”

Formation of Terpenes in Grapes and Wines

“…Other terpenes can be transformed into ketons, for example α-ionone and β-ionone. Monoterpene ketonepiperitone, is associated with the mint shade detected in aged Bordeaux wine (Jackson 2016;Picard et al 2016).…”