Macrowine 2021
IVES 9 IVES Conference Series 9 Evaluation of three alternative strategies for the long-term remediation of reductive off-odours in wines

Evaluation of three alternative strategies for the long-term remediation of reductive off-odours in wines

Abstract

Sulfur-like off-odours are a problem caused by the presence of free forms of volatile sulphur compounds (VSCs). H2S is the most frequently found above its odour threshold (1-10 µg/L), followed by methanethiol (MeSH). Recent evidences showed that the usual treatments to eliminate VSCs from wine e.g.: addition of Cu salts or micro-oxygenation only delay the occurrence of reductive off-odours. (Vela et al., 2017, 2018) The present work aims to assess the effectiveness of three alternative remediation strategies on the removal of VSCs:

1.- intensive oxygenation in the presence of a 3-mercaptopropyl-functionalized adsorbent (MPS);

2.- purging out with N2 the wine stored in reductive conditions; and,

3.- incubation with lees. The treatment with MPS consisted in the addition of 1 mM (of -SH groups) of the functionalized adsorbent to two different wines.

They were further saturated with air and, after three days, were centrifuged and analysed. The purge with N2 was applied to two different wines, which had been previously stored during 2 weeks at 50ºC under anoxia. They were purged at 100 mL/min during 60 min and analysed after the treatment. For lees treatment, three different types of lees were studied: fresh active lees, fresh inactive lees and commercial inactivated dry yeast. They were added (3,3 g/L) to wines with reductive off-odour, then they were incubated for 16 weeks at 25ºC, with weekly agitation. After the incubation, the wines were centrifugated to remove the lees. VSCs and redox potential of wines were analysed by GC-SCD (Ontañón et al., 2019) before and after each essay. Additionally, after the treatments an accelerated reductive aging was carried out (incubation at 50ºC under anoxia for 2 weeks) to assess the long-term effect of the treatments. Intensive oxygenation was very effective (-85% H2S BR after treatment and accelerated aging in both cases). Purge treatment was effective only in the short time, removing completely free H2S free and -70% BR-H2S. However, it was not effective in the long-term. The use of inactivated dry yeast was ineffective. The use of active or inactive fresh lees was effective only in some cases. In conclusion, oxidation with MPS provides the most effective treatment; purging was effective only in the short-term; and treatments with lees were not conclusive. Further studies to assess side effects of oxidation with MPS on wine characteristics should be carried out.

DOI:

Publication date: September 13, 2021

Issue: Macrowine 2021

Type: Article

Authors

Diego Sánchez-Gimeno

Diego Sánchez-Gimeno, Laboratory  of Aroma Analsis and Oenology (LAAE), Instituto Agroalimentario de Aragón –IA2-; Departamento de Química Analítica, Facultad de Ciencias, Universidad de Zaragoza, 50009. Zaragoza, Spain,Ignacio Ontañon, LAAE, –IA2- Universidad de Zaragoza Vicente Ferreira, LAAE, –IA2- Universidad de Zaragoza

Contact the author

Keywords

reduction, off-odours, vscs, lees, purge

Citation

Related articles…

The influence of culture medium on the dynamics of fermentation of wine yeasts

Wine yeast strains Saccharomyces ellipsoideus have important applications in food industry and in this regard is sought isolation as pure cultures and selecting those strains, which in laboratory investigations which have great biotechnological properties This study was intended as the ratio of live cells and autolysates cells also the influence of culture medium on this report. Yeasts selected for this study were isolated from industrial strains of indigenous grape varieties, namely: Feteasca Royal (FR) Feteasca White (FA), black Feteasca (FN), Romanian Tamaioasa (TR), Babeasca Black (BN) and Cotnari Grasa (GC).

Monitoring gas-phase CO2 in the headspace of champagne glasses through diode laser spectrometry

During Champagne or sparkling wine tasting, gas-phase CO2 and volatile organic compounds invade the headspace above glasses [1], thus progressively modifying the chemical space perceived by the consumer. Gas-phase CO2 in excess can even cause a very unpleasant tingling sensation perturbing both ortho- and retronasal olfactory perception [2]. Monitoring as accurately as possible the level of gas-phase CO2 above glasses is therefore a challenge of importance aimed at better understanding the close relationship between the release of CO2 and a collection of various tasting parameters.

Sparkling wines and atypical aging: investigating the risk of refermentation

Sparkling wine (SW) production entails a two-steps process where grape must undergoes a primary fermentation to produce a base wine (BW) which is then refermented to become a SW. This process allows for the development of a new physicochemical profile characterized by the presence of foam and a different organoleptic profile.

Wine odors: chemicals, physicochemical and perceptive processes involved in their perception

The odors of wines are diverse, complex and dynamic and much research has been devoted to the understanding of their chemical bases. However, while the “basic” chemical part of the problem, namely the identity of the chemicals responsible for the different odor nuances, was satisfactorily solved years ago, there are some relevant questions precluding a clear understanding. These questions are related to the physicochemical interactions determining the effective volatilities of the odorants and, particularly, to the perceptual interactions between different odor molecules affecting in different ways to the final sensory outputs.

Contribution of soil and atmospheric conditions to leaf water potential in grapevines

Etant lié au sol et aux conditions atmosphériques, le statut hydrique influence la physiologie de la vigne d’une part, mais joue aussi un role important en ce qui concerne la qualité du raisin et donc du vin d’autre part. Nous avons mesuré, dans la région de Stellenbosch, le statut hydrique sur des pieds de Sauvignon Blanc non irrigués, implantés sur 2 terroirs différents, l’un froid, l’autre plus chaud.