Aroma diversity of Amarone commercial wines

Abstract

Amarone is an Italian red wine produced in the Valpolicella area, in north-eastern Italy. Due to its elaboration with withered grapes, Amarone is a rather unique example of dry red wine. However, there is very limited data so far concerning the volatile composition of commercial Amarone wines, which also undergo a cask aging of 2-4 years before release. The present work aims at characterizing the aroma composition of Amarone and to elucidate the relationships between chemical composition and sensory characters.  Two sets of Amarone wines from different vintages 2015 (17 wines) and 2016 (15 wines) were analyzed. The analyses were carried out by means of Gas Chromatography-Mass Spectrometry (GC-MS) and extracted by Solid Phase Extraction (SPE) and Solid Phase Micro Extraction (SPME). In addition, the sampled wines were subjected to a sensory evaluation in the form of sorting task. From both data sets, 70 volatile compounds were successfully identified and quantified, 30 of which were present in concentrations above their odor thresholds in all the samples. Using the odor activity value (OAV), the compounds that potentially contribute to Amarone perceived aroma are b-damascenone, ethyl and isoamyl acetate, ethyl esters (hexanoate, octanoate, butanoate, 3-methybutanoate), 4-ethyl guaiacol, 3-methylbutanoic acid, dimethyl sulfide (DMS), eugenol, massoia lactone, 1,4-cineol, TDN, cis-whisky lactone. The only differences found between the two vintages’ OAV list, could be observed in the presence of dimethyl trisulfide (DMTS) in the vintage 2015; whereas in the 2016 set g-nonalactone and trans-whisky lactone were found. Regarding the compounds that impart the most differences across both vintages, OAV max/min, where 4- ethyl phenol, 4-ethyl guaiacol, 1,8-cineole, 1,4-cineole, dimethyl sulfide (DMS). Results from the sorting task sensory analysis of the 17 wines from vintage 2015 showed three clusters formed. Cluster 1 composed of eight wines and described as “red fruit”, “solvent” and “sweet spices”. Cluster 2 formed by four Amarone was associated mainly with the “animal” and “oak/toasted” attributes. And cluster 3 (five wines) described with the attribute “cooked fruit”. While in the sorting task of vintage 2016 (15 wines) two clusters were formed: cluster A formed by 5 wines described as “cooked fruit” and “solvent”; and cluster B (10 wines) associated with the attributes “sweet spices”, “red fruit” and “oak/toasted”. To our knowledge the present research is the first attempt to identify and classify Amarone della Valpolicella commercial wines in terms of aroma. This study provides a list of compounds that can be characteristic of Amarone wine and that have been consistent across two vintages coming from different wineries . Moreover, from the volatiles analyzed, compounds such as dimethyl sulfide (DMS) and cineoles have been singled out as potential aroma markers of diversity in Amarone wines