Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 Influence of pre-fermentative steps on varietal thiol precursors

Influence of pre-fermentative steps on varietal thiol precursors

Abstract

The content of 3-sulfanyl-1-hexanol and its acetate ester in wine is affected by a number of factors, including the concentration of its precursors 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) in the grape must. The role of grape must extraction steps on the content of volatile thiol precursors (VTP) in must fractions was investigated.

Grillo grape must samples were drawn along with the grape must extraction process in a winery under either air-exposed or air-free conditions, as well as under laboratory conditions and their VTP and glutathione (GSH) content was assessed by UPLC-HRMS. The roles of copper ions and sulfite were also investigated.

Under industrial conditions, more than 95% of the grape G-3SHal was lost following to the grape crushing due to sulphite addition. The content G-3SH and Cys-3SH increased with the must yield, specially under air-exposed conditions, while the GSH level decreased. Under laboratory conditions, trace amount of 3-SHal was obtained when air-free condition was applied or sulfite was added, instead milligrams per litre levels were obtained if air-exposed condition was applied, especially (14.5 mg/L) when copper sequestering salts were added. Negligible amounts of GSH (as well as grape reaction product) were detected in all the laboratory-made samples except when sulphite was added (GSH=33 mg/L).

The data strongly suggest that G-3SHal in grape must is mainly produced along with must extraction following to the binding of GSH to (E)-2-hexenal which is readily reduced to G-3SH. Sulfite addition strongly prevents the VTP formation, as well as copper ions. Therefore, grape must extraction must be considered among the main factors affecting the VTP content in grape must.

DOI:

Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article

Authors

Daniela Fracassetti, Ivano De Noni, Milda Stuknytė, Valentina Pica, Antonio Tirelli

Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Via G. Celoria 2, Milan, Italy

Contact the author

Tags

Enoforum 2021 | IVES Conference Series

Citation

Related articles…

The legal concept of “cultural heritage” to refurbish the wine sector’s priorities

Following the latest oiv global report (april 26, 2024), the prevailing perception of wine consumption finds itself undergoing one of its most challenging adjustments. It’s plausible to anticipate a shift in the scope of pdo wines towards more human-centered products (wells and stiefel, 2019), necessitating the entire sector to adapt strategies to public interest patterns (touzeau, 2010: 17-31). Previously, a dominant notion of cultural property underscored the value of wine regions; the primary interest revolved around estate owners and retailers, along with vigneron tales.

Read More

Parcours de découverte des terroirs viticoles

A partir des recherches conduites sur la caractérisation des terroirs viticoles par des chercheurs de l’Unité de Recherches Vigne et Vin (1, 2, 3, 4, 5) du Centre INRA d’Angers, Terre des Sciences, le Centre de Culture Scientifique et Technique d’Angers (CCSTA) a mis au point un parcours de découverte d’une journée dans le vignoble angevin avec une approche pluridisciplinaire.

Read More

High-throughput direct monitoring of microbial resources for oenology by direct injection mass spectrometry

Microorganisms have been widely used in oenology since prehistoric times. Their metabolism significantly impacts many wine properties and is particularly essential for the production of flavor compounds, thereby affecting perceived wine quality.

Read More

Characterization of the DOC wine “Colli Piacentini Gutturnio” obtained in three traditional areas

The poster presents the results of the 3rd year of activity of the project “Characterization of the wine productions of the italian regions. The DOC wine Colli Piacentini Gutturnio”.

Read More

The 1000 grapevine genomes project: Cataloguing Australia’s grapevine germplasm

Grapevine cultivars can be unequivocally typed by both physical differences (ampelography) and genetic tests. However due to their very similar characteristics, the identification of clones within a cultivar relies on the accurate tracing of supply records to the point of origin. Such records are not always available or reliable, particularly for older accessions. Whole genome sequencing (WGS) provides the most highly detailed methodology for defining grapevine cultivars and more importantly, this can be extended to differentiating clones within those cultivars.

Read More