OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Chemical and Biochemical reactions, including grape and wines microorganisms impact 9 Are dicysteinyl polysulfanes responsible for post-bottling release of hydrogen sulfide?

Are dicysteinyl polysulfanes responsible for post-bottling release of hydrogen sulfide?

Abstract

Hydrogen sulfide (H2S) has a significant impact on wine aroma attributes and wine quality when present at concentrations above its aroma threshold of 1.1 to 1.6 μg/L. Therefore, the management of H2S concentrations in wines, whether from fermentation or “other” origins, is an important consideration for winemakers. The main techniques used for H2S removal are oxidative handling and/or copper fining; however, the effectiveness of these treatments may be temporary, as H2S can often reappear post-bottling along with other volatile sulfur compounds (VSCs) when reductive conditions are re-established. Moreover, it is proposed that oxidative treatments applied in the presence of copper may produce compounds such as disulfides and diorganopolysulfanes, which might initially appear stable but are susceptible to reductive cleavage, thereby potentially acting as latent sources of H2S. 

The aim of this study was to determine whether putative polysulfanes could act as latent sources of H2S during post-bottling storage. Experiments conducted in model wine enabled identification of four dicysteinyl polysulfanes when H2S was oxidised in the presence of cysteine, copper and iron. The stability of the dicysteinyl polysulfanes formed in-situ was evaluated and conditions impacting the release of H2S from the polysulfanes were also determined, which provided some understanding of the possible mechanisms of release. 

The results of this study showed that the stability of the dicysteinyl polysulfanes decreased as sulfur chain length increased, which accorded with the relative proportions of polysulfanes initially formed. 

Notably, H2S was released over time, with the greatest decline in polysulfane relative abundance and largest release of H2S (up to 212 μg/L) being associated with the addition of commonly used reducing agents, especially sulfur dioxide, to the model wines containing the polysulfanes. Desulfurisation of cysteine could account for only minor quantities of H2S. In addition, Cysteine-S-sulfonates were tentatively identified by mass spectrometry after six months of storage, and similarly to the parent polysulfanes, their relative concentrations decreased with increasing number of linking sulfur atoms. These results shed light on the potential pathways for reformation of VSCs in bottled wine and demonstrate that dicysteinyl polysulfanes may have the potential to act as latent sources of H2S in wine post-bottling, potentially via a sulfitolysis mechanism.

DOI:

Publication date: June 11, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Marlize Bekker , David Jeffery, Gal Kreitman, John Danilewicz

The Australian Wine Research Institute PO Box 197 – Glen Osmond SA 5064 – Australia

Contact the author

Keywords

Polysulfanes, S-sulfonate, Copper, Sulfur dioxide 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Relation entre les caractéristiques des fromages d’Appellation d’Origine Contrôlée et les facteurs de production du lait

Les fromages d’Appellation d’Origine Contrôlée (AOC) représentent un enjeu économique important pour la filière laitière (11 % des fromages produits en France sont des fromages d’AOC, et dans certaines régions de montagne, cette proportion dépasse 50 %). Les spécificités de ces fromages et leurs liaisons avec les caractéristiques du terroir constituent un système complexe où interagissent en particulier la technologie fromagère et les caractéristiques des laits (composition chimique en particulier). Ces dernières dépendent elles-mêmes des caractéristiques des animaux (origine génétique, facteurs physiologiques, état sanitaire) et de leur mode de conduite (alimentation, hygiène, traite…) (fig. 1). L’influence de ces facteurs de production (alimentation et type d’animal en particulier) sur les caractéristiques des fromages est fréquemment mise en avant par les fromagers, sur la base d’observations empiriques. Il existe cependant très peu de travaux expérimentaux sur le sujet, en raison, entre autres, de la difficulté de séparer correctement les effets propres de ces facteurs d’amont de ceux liés à la technologie fromagère.

Shading grapevines with dynamic agrivoltaics address the challenge of early ripening and wine quality related with climate change

Context and purpose of the study. Climate change accelerates grapevine’s phenology, advancing harvests by 2–3 weeks over the past 40 years negatively affecting wine style due to a lack of acidity and too much alcohol.

DNA-free genome editing confers disease resistance in grapevine varieties

The grapevine is facing significant challenges due to climate change, as rising temperatures impact its physiological traits and disrupt plant phenology.

Implications of herbicide, cultivation or cover crop under-vine soil management on the belowground microbiote

Soil management through cover crops in the lines of the vineyards is a common practice in viticulture, since it improves the characteristics of the soil. It has been shown that the cover crops can influence the cycle of nutrients, promote infiltration, decrease erosion, and enhance the soil microbiota biodiversity improving the grapevines. However, the area under the vines tends to be left bare by applying herbicides or tillage to avoid competition with the crop in hot climates. The use of cover crops under the vines might be a plausible alternative to the use of herbicides or cultivation, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status and belowground microbial communities.

Climat-roche-sol-fromage. Cartographie fonctionnelle du terroir. Exemple de l’A.O.C. Comté

La place prépondérante que prend le Massif Jurassien en Franche-Comté confère à la région un caractère montagneux qui a orienté l’agriculture vers l’élevage laitier. Cette vocation pastorale marquée et de rudes conditions climatiques sont à l’origine de la production, attestée depuis l’Antiquité, d’un fromage de réserve pour la longue période hivernale. Cette tradition fromagère, liée à des prairies naturelles, a perduré jusqu’à nos jours. La qualité et la spécificité du produit actuel, le fromage de Comté, ont été reconnues dès 1952 par l’attribution d’un label et dès 1958, par la reconnaissance d’un périmètre d’appellation d’origine contrôlée, l’A.O.C. Comté (fig. 1).