Grape metabolites, aroma precursors and the complexities of wine flavour
Abstract
A critical aspect of wine quality from a consumer perspective is the overall impression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components. Grapes contribute some potent aroma compounds, together with a large pool of non-volatile precursors (e.g. glycoconjugates and amino acid conjugates). Aroma precursors can break down through chemical hydrolysis reactions, or through the action of yeast or enzymes, significantly changing the aroma profile of a wine during winemaking and storage. In addition, glycoconjugates of monoterpenes, norisoprenoids and volatile phenols, together with sulfur-conjugates in wine, provide a reservoir of additional flavour through the in-mouth release of volatiles which may be perceived retro-nasally. In this presentation a summary will be presented about recent research into the contribution to wine aroma and flavour from glycoside precursors of terpenes [1], norisoprenoids [1, 2] and phenols [3, 4], and also about aroma compound formation from sesquiterpene- [5] and sulfur-precursors [6, 7]. The diverse mechanisms involved in formation and degradation of wine aroma precursors will be discussed, as well as practical implications for grape growing and winemaking.
1. Black et al. (2015) Terpenoids and their role in wine flavour: recent advances. AJGWR 21, 582–600. 2. Kwasniewski et al. (2010) Timing of cluster light environment manipulation during grape development affects C13 norisoprenoid and carotenoid concentrations in Riesling. JAFC 58, 6841–6849. 3. Parker et al. (2012) The contribution of several volatile phenols and their glycoconjugates to smoke related sensory properties of red wine. JAFC 60: 2629-2637. 4. Mayr et al. (2014) Determination of the importance of in-mouth release of volatile phenol glycoconjugates to the flavor of smoke-tainted wines. JAFC 62: 2327-2336. 5.Herderich et al. (2015) Terroir effects on grape and wine aroma compounds. In: Advances in Wine Research; ACS Symposium Series 1203, 131-146. 6. Capone et al. (2012) Effects on 3-mercaptohexan-1-ol precursor concentrations from prolonged storage of Sauvignon Blanc grapes prior to crushing and pressing. JAFC 60: 3515-3523. 7.Viviers et al. (2013) Effects of five metals on the evolution of hydrogen sulfide, methanethiol, and dimethyl sulfide during anaerobic storage of Chardonnay and Shiraz wines. JAFC 61: 12385-12396.
Issue: Macrowine 2016
Type: Article
Authors
*AWRI