Volatile flavour of wine: Correlation between instrumental analysis and sensory perception

Abstract

The aroma of wine consists of 600 to 800 aroma compounds from which especially those, typical for the variety, are already present in the grapes. There are significant varietal differences between the aromagrams ('fingerprint patterns'). Thus the amount of some flavour compounds ('key substances') shows typical dependence on the variety. Especially monoterpene compounds play an important role in the differentiation of wine varieties. The German white wines can be differentiated into three groups only by quantitative determination of 12 monoterpenes ('terpene profile'). These groups are: 'Riesling type', 'Muscat type' and 'Silvaner-Weissburgunder type'. Such 'terpene profiles' are also useful for the separation of real Riesling wines from others called Riesling (e.g. Welschriesling, Kap Riesling, Emerald Riesling) but not produced from grapes of the variety Riesling. Including further components and by means of statistical methods (discriminant analysis) even the different varieties within the mentioned groups for instance the 'Riesling'-group (e.g. Riesling, Kerner, Ehrenfelser, Bacchus, Müller-Thurgau) can be separated from each other. An analytical characterization of the neutral ('Silvaner-type') grape varieties Silvaner, Ruländer (Pinot gris), Weissburgunder (Pinot blanc) is also possible with about 20 compounds (e.g. monoterpenes, alcohols). Computing at the same time free and glycosidically bound aroma components (monoterpenes, alcohols, norisoprenes) in discriminant analysis the characterization of the neutral grape varieties can be considerably improved. To identify compounds causing 'off-flavours' sniffing technique is the method of choice. The off-flavour is pinpointed during gas chromatographic separation of the complex aroma mixture by effluent sniffing. Once allocated, the chemical nature of the off-flavours is elucidated by spectroscopic methods. Substances contributing to the green pepper taint, the strawberry note, moussiness, corkiness, etc. in wine could be found in this way.

The Aroma of Rojal Red Wines from La Mancha Region – Determination of Key Odorants

“…Formation of volatile compounds begins in the grape, while during juice production, fermentation, maturation, ageing and storage the chemical composition continues to change. The amount and type of chemicals that influence wine flavour therefore depend on many factors including the origin of the grapes, grape varieties and ripeness, soil and climate, yeast used during fermentation and a variety of other winemaking practices (Kotseridis & Baumes, 2000;Rapp, 1998;Spranger et al, 2004).…”

Comparison between aroma compounds in wines from four Vitis vinifera grape varieties grown in different shoot positions

“…Some of the aroma compounds are released directly from the grape berries while others are formed during the process of fermentation and aging (Rapp, 1998). The most important flavor compounds in wine made from neutral grape varieties are those arising from the fermentation process, which include mainly ethyl esters, acetate esters, higher alcohol, fatty acids, and aldehydes.…”

Genome-wide association analysis on five isolated populations identifies variants of the HLA-DOA gene associated with white wine liking

“…The taste of wine depends on many different sensory perceptions ranging from taste and olfaction to texture. 7 Wine is a mixture of thousands of molecules that can contribute to its final taste, 8 and its composition varies greatly depending on the grapes used, climate and production method. 9 Although the flavor of some of these compounds is very well known, it is really difficult to understand what their role in final taste is.…”