IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Varietal thiol precursors in Trebbiano di Lugana grape and must

Varietal thiol precursors in Trebbiano di Lugana grape and must


Trebbiano di Lugana (TdL) is a white variety of Vitis vinifera mainly cultivated in an Italian area located south near Garda lake (Verona, north of Italy). This grape cultivar, also known as “Turbiana,” is used for the production of TdL wine with recognized Protected Designation of Origin whose volatile profile was recently determined [1]. The presence of varietal thiols in TdL, namely 3-mercaptohexan-1-ol and its acetate form, conferring the tropical and citrus notes, has been documented. Winemaking strategies were also described with the purpose of protecting and maintain these desired aromas [2]. To the best of our knowledge, the varietal thiol precursors (VTPs) were not previously determined in TdL grape and must. This study aimed to quantify VTPs in both grape during the ripening and must during the pressing. Volatile C6 compounds were also measured in the must fractions.
TdL grapes were sampled during the ripening in two vineyards, differing for the content of readily assimilable nitrogen (RAN), for a total of five samplings each. The musts were produced in an industrial plan collecting the samples during the pressing for a total of nine samplings [3]. VTPs were identified and quantified in grape fractions, grape samples and must fractions by ULPC coupled High Resolution Mass Spectrometry (HRMS) after SPE of samples [4]. Volatile C6 compounds, namely trans-2-hexen-1-ol, trans-3-hexen-ol, 2-hexenal, 1-hexanol, cis-3-hexen-1-ol and cis-2-hexen-1-ol, were determined by SPME-GC/MS [5].
S-3-(hexan-1-ol)-L-glutathione (G-3SH), S-3-(hexan-1-ol)-L-cysteine (Cys-3SH) and S-3-(hexanal)-glutathione (G-3SHal) were detected in both grape and must samples. At harvest, grapes with lower RAN revealed about 3-folds lower levels of G-3SH (79.71±0.97 μg/L vs. 208.66±1.35 μg/L) and G-3SHal (4.7±0.1 mg/L vs. 13.1±0.0 mg/L), and 2-folds lower amounts of Cys-3SH (11.95±0.82 μg/L vs. 21.75±0.47 μg/L). This suggests the level of RAN in grape to affect VPT synthesis. Nonetheless, the musts obtained with the two grapes showed comparable concentrations of G-3SH (50.71±0.37 μg/L as average); Cys-3SH was found at trace levels in both musts, and little amounts of G-3SHal was detected only in the must with higher RAN (29.53±7.37 μg/L). Considering the volatile C6 compounds, trans-3-hexen-1-ol, cis-3-hexen-1-ol and cis-2-hexen-1-ol were similar in the two investigated musts; trans-2-hexen-1-ol was higher in the must with low RAN as well as 2-hexenal and 1-hexanol. No significant correlation was found between the VPTs and volatile C6 compounds in the must fractions analysed.
These data suggest RAN to impact the VPT concentrations in grape. Moreover, pressing was found to play an important role on VPTs content of musts.


[1] Fracassetti D., Camoni D., Montresor L., Bodon R., Limbo S. Chemical characterization and volatile profile of Trebbiano di Lugana wine: A case study. Foods 2020, 9, 956. https://doi.org/10.3390/foods9070956.
[2] Mattivi F., Fedrizzi B., Zenato A., Tiefenthaler P., Tempesta S., Perenzoni D., Cantarella P., Simeoni F., Vrhovsek U. Development of reliable analytical tools for evaluating the influence of reductive winemaking on the quality of Lugana wines. Anal. Chim. Acta 2012, 732, 194–202. https://doi.org/10.1016/j.aca.2011.11.051.
[3] Tirelli A., De Noni I., Stuknytė M., Pica V., Fracassetti D. Role of extraction procedures on the concentration of varietal thiol precursors in Grillo white grape must. Aust. J. Grape Wine Res. 2022, 28, 61-69. https://doi.org/10.1111/ajgw.12514.
[4] Fracassetti D., Stuknyté M., La Rosa C., Gabrielli M., De Noni I., Tirelli A. Thiol precursors in Catarratto Bianco Comune and Grillo grapes and effect of clarification conditions on the release of varietal thiols in wine. Aust. J. Grape Wine Res. 2018, 24, 125-133. https://doi.org/10.1111/ajgw.12311.
[5] Bosso A., Follis R., Guaita M., Motta S., Panero L., Petrozziello M. Caratterizzazione del quadro polifenolico ed aromatico di mosti di 5 diverse cultivar a bacca bianca, sottoposti a pressatura all’aria a sotto azoto. From “Territori di vini-progetti di ricerca per il settore vitivinicolo” edited by Società Consortile territori Divini A.R.L. (stampa La GRAFICA FAGGIAN S.R.L.-Campodarsego (PD). Proceedings of the conference “Territori diVini”, Treviso, 24 june 2011: 29-37.


Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster


Fracassetti Daniela1, De Noni Ivano1, Petrozziello Maurizio2, Bonello Frederica2 and Tirelli Antonio1 

1Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano
2CREA-VE Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria – Centro di Ricerca Viticoltura ed Enologia

Contact the author


Grape ripening, Pressing, C6 compounds, Must


IVAS 2022 | IVES Conference Series


Related articles…

New acacia gums fractions: how their features affect the foamability of sparkling base wines?

When sparkling wine is served, the first attribute perceived is foam1. Bentonite is usually added to wine in order to cause particle flocculation

Fingerprinting the origin of rosé wines with a new high throughput polyphenomics method

Wine is a widely consumed alcoholic beverage with a high commercial value. More specifically, the worldwide consumption of rosé wine has increased by 20% since 2002[1]. But because of its high commercial value, it can become a subject of fraud, and authenticity control is necessarily required. More than one hundred polyphenols have been recently quantified in various rosé wines [2]. They are key components defining color, taste and quality of wines. Their amount and composition depend on many different factors such as grape variety, winemaking and age of the wine. In this study, the influence of geographic origin of some rosé French wines was investigated. An original and very fast UPLC-QTOF-MS method was developed and used to predict the geographic origin authenticity of rosé wines.

Tools for assessing vine nitrogen status; role of nitrogen uptake in the “terroir” effect

Among the numerous nutrients vines extract from the soil, nitrogen is the one that interferes most with vine vigor, yield, berry constitution and wine quality. Many studies relate on the influence of various levels of nitrogen

Il Cabernet di Atina dal 1850 al giorni nostri: un esempio di valorizzazione del territorio

In the province of Frosinone from 1850 they are cultivated in some zones wine grape of French origin like Merlot, Cabernet franc Cabernet sauvignon, Sirah, Pinot noir. The insertion of these varieties was the work of Pasquale Visocchi in the great company of family “Fratelli Visocchi Proprietari” (F. V.P.).

Untargeted metabolomics to identify potential chemical markers responsible for the permissiveness of red wines against Brettanomyces bruxellensis

Red wines constitute the majority of the wines produced in Bordeaux. All along the winemaking process, many microorganisms may develop in wine. A lot of them are useful but a common defect found in wine is linked to the development of Brettanomyces bruxellensis, a yeast that produces volatile phenols. These molecules are responsible for an unwanted sensorial defect described as similar to “horse sweat”, “burnt plastic” or “leather”. It has been shown that while some wines are very permissive and easily contaminated, others are pretty resistant to Brettanomyces development. However, common parameters such as pH, alcohol or sugars composition cannot fully explain the differences observed in wine permissiveness.