The sesquiterpene rotundone is an impact aroma in Gruener Veltliner and other peppery wines

Rotundone is a sesquiterpenoid ketone identified as responsible for the ‘peppery’ aroma of white and black pepper, herbs and spices but also of grapes and wine. The development of an effective method for its detection and quantification in grapes and wine, based on solid-phase micro-extraction, gas chromatography and tandem mass spectrometry, was effectively applied to discover the origin of the peppery aroma in both red and white wines. A survey of European wines selected on the basis of their ‘peppery’ character revealed that the presence of rotundone is relatively widespread in V. vinifera wines. High levels of this aroma were found in red varieties such as Schioppettino and Vespolina. For the first time this compound was reported in the white variety Gruener Veltliner, at levels up to 17 times the sensorial threshold. Analysis of different Gruener Veltliner clones showed that the levels of rotundone accumulation could be a clonal trait. Rotundone was shown to accumulate almost exclusively in berry exocarp, suggesting that skin contact during winemaking could contribute to enriching ‘peppery’ notes in wine.