# Characterization of the Aroma Profile of Commercial Prosecco Sparkling Wines
## Results and Discussion
### Effect of the PDO on Volatile Profile  
In order to evaluate the influence of the area of origin on the aromatic composition of the wines, the data were subjected to non-parametric analysis by Kruskal-Wallis test (\(\alpha\) = 0.1). Even if the dataset was not balanced among the production areas, some observations could be obtained. Samples from the three areas were quite similar for most compounds, with only 24 compounds (11 terpenes, 6 VSC, 2 norisoprenoids, 2 benzenoids and 3 fermentative compounds) showing significant differences (Table 3). The 11 terpenes were nerol, geraniol, \(\alpha\)-phellandrene, limonene, \(\gamma\)-terpinene, p-cymene, \(\alpha\)-terpinene, \(\beta\)-myrcene, 3-carene, \(\beta\)-pinene, and rose oxide. These terpenes were generally found in higher concentration in Asolo samples, except for nerol, which was higher in Valdobbiadene samples. In fact, it has been observed that terpenes are influenced by the origin of the grapes as well as by viticultural practices [12; 42; 43]. Even if the two areas are very close, the historical series of weather data indicates differences, for example, in terms of annual temperatures, with Asolo tending to be slightly colder \"[[https://www.arpa.veneto.it/dati-ambientali/open-data](https://www.arpa.veneto.it/dati-ambientali/open-data)]([https://www.arpa.veneto.it/dati-ambientali/open-data](https://www.arpa.veneto.it/dati-ambientali/open-data)) (accessed on accessed on 3 March 2023)\". However, it should be remembered that the hilly conformations can lead to considerable microclimatic differences even within the PDO itself. In this way, they could actively contribute to the geographical typicality of the wines. Among these terpenes, only nerol \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Volatile Compound** & **Odor Descriptor** & **Odor Threshold (\(\mu\)g/L) 1** & **Mean** & **Min** & **Max** \\ \hline Ethyl octanoate & Fruity & 5 & 148.2 & 83.3 & 228.6 \\ Ethyl hexanoate & Fruity & 14 & 79.8 & 59.3 & 123.6 \\ Isoamyl acetate & Banana & 30 & 52.5 & 2.0 & 173.3 \\ \(\beta\)-Damascenone & Quince & 0.05 & 30.5 & 1.4 & 104.6 \\ Octanoic acid & Rancid & 500 & 17.6 & 0.3 & 20.4 \\ Hexanoic acid & Rancid & 420 & 14.8 & 10.4 & 18.2 \\ Ethyl butanoate & Fruity & 20 & 13.5 & 3.0 & 21.3 \\
3-Methylbutanoic acid & Rancid & 33 & 7.9 & 5.2 & 10.7 \\ Ethyl 3-methylbutanoate & Red fruits & 3 & 5.6 & 0.0 & 17.1 \\ Dimethyl trisulfide & Onion & 0.2 & 3.7 & 0.3 & 19.1 \\ Isoamyl alcohol & Vinous & 30,000 & 3.1 & 2.4 & 3.7 \\ TDN & Kerosene & 2 & 1.0 & 0.0 & 4.0 \\ TPB & Tobacco & 0.04 & 0.9 & 0.0 & 3.8 \\ DMS & Truffle, Red & 10 & 0.7 & 0.3 & 1.8 \\ Phenylethyl acetate & Rose & 250 & 0.6 & 0.1 & 2.3 \\ Ethyl-2- & \multirow{2}{*}{Red fruits} & 18 & 0.5 & 0.0 & 1.5 \\ methylbutanoate & \multirow{2}{*}{Floral} & \multirow{2}{*}{25} & 0.5 & 0.0 & 3.5 \\ Linalool & & & & & \\ \hline \hline \end{tabular} 1  
\end{table} 
Table 4: Odor activity values of aroma compounds in Prosecco wines with at least one sample showing OAV > 1.  
and geraniol were linear monoterpene alcohols characterized by floral notes, the rest were cyclic monoterpenoids that could contribute to citric, turpentine and pine aromas. Asolo wines also showed the highest content of the two isoprenoids TPB and TDN. TDN concentration in wine has been reported to be influenced not only by wine age, but also by grape sun exposure, pH, and storage temperature [25,44]. TPB is characterized at low concentration by tobacco aroma notes, while at high concentration it has been described as a geranium-like aroma. The concentrations of TPB were quite low, however, thanks to the very low olfactory threshold (0.04 ug/L) [39], TPB could play a sensorial role and characterize the aroma of the wines of the Asolo area. TPB has been shown to increase during aging [26], moreover, it can react with tannins; for this reason it is more present in white wines or wines with a low concentration of polyphenols [45].