 IVES 9 IVES Conference Series 9 Chemical and biochemical formation of polysulfides in synthetic and real wines using UHPLC-HRMS

Chemical and biochemical formation of polysulfides in synthetic and real wines using UHPLC-HRMS

Abstract

AIM: Sulfur compounds in wine have been studied for several years due to their impact on wine flavour, but the role of polysulfides is a recent topic. Polysulfides in wine are formed when two sulfhydryl groups oxidize, especially in presence of elemental sulfur or metal catalysts from field treatment residues (Ugliano et al. 2011). These compounds are odourless, but can degrade during storage and affect the wine quality. The mechanism of their formation is still largely unknown but different chemical and biochemical pathways have been suggested. Disulfides from cysteine (Cys) and glutathione (GSH) have been revealed in model wines (Kreitman et al. 2016) and more recently also higher polymerized forms in real wines (Van Leeuwen et al. 2020). Volatile varietal thiols like 3-mercaptohexanol (3MH) and 4-mercaptopentanone (4MMP) – flavour compounds with tropical or fruity notes – could undergo similar reactions, also with Cys and GSH, subsequently losing their flavour property (fate). Even more concerning is the possible release of H2S from polysulfides during storage, leading to undesired off-flavours (Sarrazin et al. 2010). In the present work polysulfides from varietal thiols 4MMP and 3MH were identified for the first time in synthetic and real wines. Additionally, the evolution of glutathionyl and cysteinyl polysulfides was followed during fermentation.

METHODS: For the study of thiolated polysulfides, synthetic standards, musts and wines and commercial SB wines were supplemented with copper sulfate and wettable sulfur to induce condensation reactions. For the evolution study, synthetic must and Chardonnay juice were supplemented with elemental sulfur, CuSO4, both, or nothing (control) and subsequently fermented until sugar dryness was reached (after 18 days). All samples were analysed using ultra-high-performance liquid chromatography (UHPLC) coupled to hybrid quadrupole/high-resolution mass spectrometry (HRMS, Q-Orbitrap).

RESULTS: Thiolated polysulfides with up to 4 sulfur atoms were successfully recovered from the synthetic standards, musts and wines and characterized using Compound Discoverer. The evolution study showed different patterns of polysulfide formation for the different fermenting musts, which were assigned to the difference in matrix composition and matrix complexity. Moreover, significant differences in accumulation were revealed between the differently treated musts.

CONCLUSIONS:

The UHPLC/HRMS method used in both studies was successfully applied to detect polysulfides in different spiked synthetic and real wines. Differences between treatments and matrices proved the influence of known and unknown compounds playing an important role in polysulfide formation. The present method can be applied to perform ongoing polysulfide studies.

DOI:

Publication date: September 22, 2021

Issue: Macrowine 2021

Type: Article

Authors

Susanne Dekker , Tiziana Nardin, Mirko Mattana, Igor Fochi, Roberto Larcher, Katryna van Leeuwen, Bruno Fedrizzi, Cinzia Dell’Anna,

Edmund Mach Foundation, Thermo Fisher Scientific SpA,University of Auckland

Contact the author

Keywords

LC-HRMS; diorganopolysulfanes; polysulfides; thiols; cysteine; glutathione; wine

Citation

100 ans d’évolution des règles relatives à l’encépagement des AOC viticoles françaises : quelles perspectives face aux enjeux contemporains

To characterize a wine, the most frequently used criteria describe its color, its origin, the grape varieties from which they come, or even for white wines its residual sugar content (dry, semi-dry, sweet). In france, the system of appellations of origin set up in 1919 was initially based solely on the notoriety and origin of the wines. But given the unfavorable consequences that this lack of details generated, the public authorities quickly integrated in 1927 into the “capus” law criteria for access to designations of origin, relating to the specific characteristics of the soils of the vineyards and the grape varieties used, in particular exclusion of interspecific hybrid varieties. In 1935 the creation of the aoc system confirmed the interest in precisely defining all the production conditions that must be implemented to be able to claim the benefit of an aoc, and grape varieties were an essential condition for acquisition.

The international Internet site of the geoviticulture MCC system

The “Geoviticulture Multicriteria Climatic Classification (MCC) System” was developed to characterize the climate of the wine producing regions of the world.

Lactiplantibacillus plantarum – A versatile tool for biological deacidification

Malolactic fermentation (MLF) is a secondary wine fermentation conducted by lactic acid bacteria (LAB). This fermentation is important in winemaking as it deacidifies the wine, converting L-malic acid into L-lactic acid and carbon dioxide, and it contributes to microbial stability. Wine pH is highly selective, and at pH below 3.5 generally only strains of O. oeni can survive and express malolactic activity, while under more favorable growth conditions above pH 3.5, species of Lactobacillus and Pediococcus may conduct the MLF. Among the LAB species Lactiplantibacillus plantarum strains have shown most interesting results under hot climate conditions, not only for their capacity to induce MLF, but also for their homo-fermentative properties towards hexose sugars, which makes them suitable for induction of MLF in high pH and high alcohol wines, when inoculated at the beginning of alcoholic fermentation.

French AOC positioning and their concepts and extension to other products

Constitue une appellation d’origine “la dénomination géographique d’un pays, d’une région ou d’une localité servant à désigner un produit qui en est originaire, et dont la qualité ou les caractères sont dus exclusivement ou essentiellement au milieu géographique, comprenant les facteurs naturels et les facteurs humains …”

The environmental footprint of selected vineyard management practices: A case study from Logroño (La Rioja) Spain

Viticulture is globally important for socioeconomic and environmental reasons. The EU is globally leading grape and wine production, and Spain is among the top grape and wine producers. As climate change affects viticulture, mitigation and adaptation are crucial for protecting grape production. In this research work, data on viticultural management practices such as soil cultivation, irrigation, energy, machinery, plant protection and the use of fertilizers from vineyards located in Logroño (La Rioja) have been obtained.