 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

Grapevine rootstock field evaluation under drought and saline condition in California

Climate change impacts grape production worldwide and in California drought and salinity became increasingly challenging for grape growers to maintain sustainable production and fruit quality.

Ability of Saccharomyces cerevisiae strains to modulate the aroma of albariño wines

The objective of the present work is to evaluate the impact of three S. cerevisiae strains on the comprehensive aroma profile of Albariño wine along its shelf life.

Atmospheric modeling: a tool to identify locations best suited for vine cultivation. Preliminary results in the Stellenbosch region

The choice of sites for viticulture depends on natural environmental factors, particularly climate, as grapevines have specific climatic requirements for optimum physiological performance and berry quality achievement. In the Stellenbosch wine-producing region, the complex topography and the proximity of the ocean create a variety of topoclimates resulting in different growth conditions for vines within short distances.

Application of plant growth regulators on Vitis vinifera L var. Mouchtaro affect berry quality characteristics & associated microbial communities

The phenolic profile of the red grapevine varieties berries is a key quality factor and several techniques have been applied to improve it (Perez-Lamela et al., 2007; Singh SK and Sharma, 2010). The last decade the application of resistance elicitors and phytohormones is an innovative viticultural technique (Paladines-Quezada et al., 2021; Alenazi et al., 2019).In the present study, leaves and berries of a Greek red indigenous variety (Mouhtaro) sprayed with two elicitors, benzothiadiazole and chitosan and a plant hormone abscisic acid, during veraison.

Effects of bottle closure type on sensory characteristics of Chasselas wines

Several winemaking operations, such as filtration, pumping, and racking, are known to potentially facilitate the incorporation of atmospheric O2 into the wine. Control of grape must oxidation is one key aspect in the management of white wine aroma expression, color stability and shelf-life extension. On the one hand, controlled must oxidation may help to remove highly reactive phenolic compounds, which otherwise could contribute to premature oxidation. And on the other hand, in certain cases of extreme protection of the must from O2 (e.g. pressing under inert atmosphere), it can help to preserve varietal aromas and natural must antioxidants.