IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 The effect of sulfur compounds on the formation of varietal thiols in Sauvignon Blanc and Istrian Malvasia wines

The effect of sulfur compounds on the formation of varietal thiols in Sauvignon Blanc and Istrian Malvasia wines

Abstract

Varietal thiols 3-sulfanylhexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA) and 4-methyl-4-sulfanylpentan-2-one (4SMP) are essential for fruity aromas of Sauvignon Blanc wines. The concentration of varietal thiols in wines was thought to be related to the concentration of their precursors in grapes, however only a small proportion of precursors are released to varietal thiols during fermentation. New findings suggested that specific grape juice metabolites could significantly impact on the development of three major varietal thiols and other aroma compounds of Sauvignon Blanc wines. Among them, elemental sulfur and hydrogen sulfide indicated a positive role on the formation of varietal thiols during vinification (Araujo et al., 2016; Harsch et al., 2013). This research aimed to investigate the addition of different sources of sulfur in grape juice on formation of 3SH, 3SHA, 4SMP and benzene methanethiol (BM) in Sauvignon Blanc and Istrian Malvasia wines. Istrian Malvasia (Vitis vinifera L.) is a local grapevine variety which sometimes aromatically resemble on Sauvignon Blanc.Pressed grape juice was settled overnight and sampled from tank for microfermentations. Additions of different sulfur compounds in 700 mL of juice were performed just before yeast inoculation in four replicates each: (1) control – no addition, (2) addition of reduced glutathione (GSH) (20 and 50 mg/L), (3) addition of methionine (10 and 20 mg/L), (4) addition of cysteine (20 and 40 mg/L), (5) addition of elemental sulfur (5 and 10 mg/L) and (6) addition of  sodium hydrosulfide hydrate (1 and 10 mg/L). Fermentations were performed with Saccharomyces cerevisae (X5, Laffort, France) in 750 mL dark glass bottles at 18-20 °C. After fermentation, 50 mg/L SO2 was added, wines were settled, racked, and stored at -20 °C until analyses. Varietal thiols were analysed by GC-MS/MS (Schimadzu, TQ8050) using the modified method as described (Šuklje et al., 2013).Sauvignon Blanc wines with the addition of 10 mg/L NaSH·xH2O (which releases hydrogen sulfide) had significant higher concentration of 3SH and 3SHA compared to control and other treatments. Istrian Malvasia wines with the addition of 10 mg/L NaSH·xH2O had significant higher concentrations of 3SH but there were no significant differences in 3SHA.  The addition of elemental sulfur increased 3SH and 3SHA in both varieties, however not significantly. Addition of sulphur compounds in our study had no effect on concentration of 4MMP and BM in Sauvignon Blanc or Istrian Malvasia wines. On the other hand, the additions of GSH and cysteine resulted in significantly lower formation of 3SH and 3SHA in Sauvignon Blanc wines in comparison to control and other additions. The latter finding is compliant with the study on model wines by Alegre et al. (2019).Modifying sulfur source composition in grape juice showed some significant changes in concentration of 3SH in both Sauvignon Blanc and Istrian Malvasia wines.

References

Araujo D. L., Vannevel S., Buica A., Callerot S., Fedrizzi B., Kilmartin A. P., du Toit J. W. 2016. Indications of the prominent role of elemental sulfur in the formation of the varietal thiol 3-mercaptohexanol in Sauvignon blanc wine, Food Research International, 98, 79-86.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Vanzo Andreja1, Alenka Mihelčič1, Katja Šuklje1, Klemen Lisjak1

1 Agricultural Institute of Slovenia

Contact the author

Keywords

sulfur compounds, grape juice, varietal thiols, Sauvignon Blanc, Istrian Malvasia

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Grapevine varietal diversity as mitigation tool for climate change: Agronomic and oenologic potential of 14 foreign varieties grown in Languedoc region (France)

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Different soil types and relief influence the quality of Merlot grapes in a relatively small area in the Vipava Valley (Slovenia) in relation to the vine water status

Besides location and microclimatic conditions, soil plays an important role in the quality of grapes and wine. Soil properties influence…

Towards a regional mapping of vine water status based on crowdsourcing observations

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

Short-term relationships between climate and grapevine trunk diseases in southern French vineyards

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Modeling island and coastal vineyards potential in the context of climate change

Climate change impacts regional and local climates, which in turn affects the world’s wine regions. In the short term, these modifications rises issues about maintaining quality and style of wine, and in a longer term about the suitability of grape varieties and the sustainability of traditional wine regions. Thus, adaptation to climate change represents a major challenge for viticulture. In this context, island and coastal vineyards could become coveted areas due to their specific climatic conditions. In regions subject to warming, the proximity of the sea can moderate extremes temperatures, which could be an advantage for wine. However, coastal and island areas are particular prized spaces and subject to multiple pressures that make the establishment or extension of viticulture complex.
In this perspective, it seems relevant to assess the potentialities of coastal and island areas for viticulture. This contribution will present a spatial optimization model that tends to characterize most suitable agroclimatic patterns in historical or emerging vineyards according to different scenarios. Thanks to an in-depth bibliography a global inventory of coastal and insular vineyards on a worldwide scale has been realized. Relevant criteria have been identified to describe the specificities of these vineyards. They are used as input data in the optimization process, which will optimize some objectives and spatial aspects. According to a predefined scenario, the objectives are set in three main categories associated with climatic characteristics, vineyards characteristics and management strategies. At the end of this optimization process, a series of maps presents the different spatial configurations that maximize the scenario objectives.