A NEW TOOL TO QUANTIFY COMPOUNDS POTENTIALLY INVOLVED IN THE FRUITY AROMA OF RED WINES. DEVELOPMENT AND APPLICATION TO THE STU-DY OF THE FRUITY CHARACTER OF RED WINES MADE FROM VARIOUS GRAPE VARIETIES

Abstract

A wide range of olfactory descriptors ranging from fresh and jammy fruit notes to cooked and oxidized fruit notes could describe the fruity aroma of red wines [1]. The fruity character of a wine is mainly related to the grape variety selected, to the terroir and the vinification process applied for its conception. In white wines, some volatile compounds confer directly their aroma to the wine while the question of “key” compound is more complex in red wines. According to many studies performed over the past decades, some fruity ethyl esters are directly involved in the fruity perception of red wines while others, present at subthreshold concentrations, participate indirectly to the fruity expression via perceptive interactions [2]. However, a few non-fruity aroma compounds not belonging to ester family are known to contribute to the fruity aroma in red wines. For example, β-damascenone and β-ionone (C13-norisoprenoids) boost the fruity notes via synergic effects while 1,8-cineole (a monoterpenoid) is involved in the blackcurrant aroma of particular red wines [3, 4]. This study intends to explore the fruitiness of red wines produced from different grape varieties. An analytical method was developed and optimized using liquid-liquid extraction and gas chromatography coupled to mass spectrometry (GC/MS) to determine the concentrations of aroma compounds potentially involved in the fruity aroma of red wines. The aim of this method was to reduce sample preparation and analysis time, as this tool requires a single sample preparation and a single injection to quantify 43 aromatic compounds including 19 esters, 13 monoterpenes, 5 C13-norisoprenoids and 1 C6-aldehyde and 5 C6-alcohols. A total of 37 volatile compounds were detected and quantified in commercial single-va-rietal red wines from the 2018 vintage made from grape-varieties planted around the Mediterranean (Greece, Cyprus, Spain, Portugal and France). A generation of olfactory descriptors was coupled to instrumental analyses to investigate their fruity aromas. Samples were selected by experts according to their qualitative fruity aromas marked by “fresh red- and black-berry fruit” and “red- and black-berry jammy fruit” notes. Differences were observed regarding the variations in concentrations of several aroma compounds. Some variations are partially correlated to the olfactory descriptors cited by experts.