Sauvignon Blanc Wine: Contribution of Ageing and Oxygen on Aromatic and Non-aromatic Compounds and Sensory Composition : A Review

Abstract

Oxidation and the capacity for sufficient ageing potential of white wines are constant problems for winemakers worldwide. In general, it is accepted that certain grape varieties are especially sensitive to oxidation, suggesting that some of the chemical components key to their sensory attributes are strongly modulated by oxygen exposure. Sauvignon blanc is a well-documented example of an oxygen-sensitive wine, and understanding the stability of various compounds is crucial in order to preserve the fresh and fruity characters of Sauvignon blanc wines while preventing the formation of off-odours over a long period of time. Compounds such as the volatile thiols and methoxypyrazines are key aroma compounds responsible for the typical Sauvignon blanc aroma, while other aroma compounds, such as esters, alcohols and acids, can also contribute to the wine aroma. Oxidation-related compounds (such as aldehydes) can occur under certain conditions and it is essential to understand the chemistry behind oxidation to control and manage the development of various characteristics in wine. The sensory interactions occurring between various compounds (both aromatic and non-aromatic) are also important due to enhancing or suppressive effects that can mask certain aroma nuances. This review focuses on the stability of certain compounds of Sauvignon blanc wines during oxidation and ageing and how it affects the aromatic and non-aromatic composition of these wines. ABBREVIATIONS

The Impact of Oxygen at Various Stages of Vinification on the Chemical Composition and the Antioxidant and Sensory Properties of White and Red Wines

“…Sulphur dioxide may also limit chemical oxidation reactions by reducing the oxidation products to their original form (e.g., o-quinones to phenols). The effect on nonenzymatic oxidation reactions is based on the reaction with hydrogen peroxide, but not directly on the reaction with oxygen (in the typical wine pH, this reaction occurs very slowly and is not significant) [10,[13][14][15][16].…”

“…Particularly susceptible to the changes in the quality of aroma are wines produced from less aromatic fruits, which due to the low concentration of aroma-forming compounds are oxidized faster [38]. Aromas which are perceptible in oxidized white wine are described as the smell of caramel, rotten fruit, wood, and cooked vegetables [13,39]. As a result of the oxidation of higher alcohols, aldehydes are formed, e.g., 3-(methylthio)propionaldehyde, which create the aroma of honey and boiled vegetables.…”

“…These compounds cause the formation of wood aroma, although white wines are not usually matured in barrels. 5-Methylfurfural and 5hydroxymethylfurfural at high concentrations are characteristic of Port and Madeira wines, where these accumulate as a result of high temperature during aging in oak barrels [13,40]. The oxidation of ethanol by hydrogen peroxide causes the formation of acetaldehyde, which constitutes the largest amount of the aldehydes formed.…”

“…The oxidation of ethanol by hydrogen peroxide causes the formation of acetaldehyde, which constitutes the largest amount of the aldehydes formed. The aroma caused by acetaldehyde is associated with an acrid, grassy smell and adversely affects the aroma of wine [13,41]. In turn, [1] state that even high concentrations of acetaldehyde do not affect the aroma of wine.…”

Application of Volatile Compounds Analysis for Distinguishing between Red Wines from Poland and from Other European Countries

“…There are hundreds of volatile compounds in wines. Aroma formation is influenced by several factors: grape variety, climate, soil, region, cultivation, yeast, oenological techniques and ageing (Du et al, 2012;Coetzee & Du Toit, 2015).…”