Macrowine 2021
IVES 9 IVES Conference Series 9 Ability of Saccharomyces cerevisiae strains to modulate the aroma of albariño wines

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

Abstract

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.

The strains Lalvin QA23TM, Lalvin SauvyTM and Affinity ECA5TM (Lallemand Bio) fermented a model must containing precursors of polyfunctional mercaptans (PFMs) and a polyphenolic and aroma precursor fraction1 extracted from Albariño grapes. Wines were submitted to accelerated anoxic aging at 50 ºC during 1, 2, 5, 8 weeks and at 75 ºC during 12, 24, 48, 72h of aging, respectively. Fermentative aroma compounds, SO2, Strecker aldehydes, and varietal aroma compounds were determined by GC, using six different analytical methods.

The aroma profiles of the Albariño wines obtained are characterized by low amounts of volatile phenols, vanillin derivatives and TDN precursors and by medium to high levels of linalool, β-damascenone, rose oxide, γ-nona and γ-decalactones, which explain the typical and subtle floral aroma notes associated with Albariño wines2. Levels of linalool faded during aging, but floral notes may be partially compensated by increasing levels of ethyl cinnamate.

The ability of the strains assayed to modulate levels of terpenes and lactones was limited citronellol and rose oxide. They were able to influence slightly but significantly levels of β-damascenone and ethyl cinnamate in aged wines. This suggests that the influence of the strains on floral notes is significant, but not dominant3. In clear contrast, the strains introduced a great variability in the levels of PFMs which mostly remained all along wine shelf life.

Even if aging was carried out under strict anoxic conditions, levels of Strecker aldehydes increased, isobutanal and 2-methylbutanal in a strain-dependent way, suggesting that Strecker degradation of amino acids took place with already present wine α-dicarbonyls. Levels of diacetyl and isovaleric acid increased during aging, in spite of the fact that aging conditions were not adequate for microbial development.

Regarding fermentative compounds, levels of higher alcohols and their acetates, straight and branched chain fatty acids and their ethyl esters as well as Strecker aldehydes were strongly strain-dependent. Except for acetates, differences were maintained during aging or even intensified in the cases of aldehydes and ethyl esters of branched acids.

Finally, aging at 50 and 75 ºC were in general very well correlated, suggesting that aging at 75ºC can satisfactorily predict evolution during aging of many wine components. aging at 75ºC can satisfactorily predict evolution during aging of many wine components, except PFMs and Strecker aldehydes.

S. cerevisiae strains can be used to produce Albariño wines with completely different sensory profiles and different sensory evolutions during aging. While the effects on varietal floral and sweet aroma compounds was just moderate, effects on PFMs and fermentative aroma compounds, including Strecker aldehydes were very large.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Marie Denat 

Laboratory for Aroma Analysis and Enology (LAAE), University of Zaragoza, Instituto Agroalimentario de Aragón (IA2) (UNIZAR-CITA), Zaragoza (Spain)  ,Vicente FERREIRA, (LAAE), University of Zaragoza, Instituto Agroalimentario de Aragón (IA2), Zaragoza (Spain) Ignacio ONTAÑÓN, (LAAE), University of Zaragoza, Instituto Agroalimentario de Aragon (IA2), Zaragoza (Spain)

Contact the author

Keywords

cerevisiae, fermentation, wine aging, albariño, polyfunctional mercaptans, strecker aldehydes

Citation

Related articles…

Long-term drought resilience of traditional red grapevine varieties from a semi-arid region

In recent decades, the scarcity of water resources in agriculture in certain areas has been aggravated by climate change, which has caused an increase in temperatures, changes in rainfall patterns, as well as an increase in the frequency of extreme phenomena such as droughts and heat waves. Although the vine is considered a drought-tolerant specie, it has to satisfy important water requirements to complete its cycle, which coincides with the hottest and driest months. Achieving sustainable viticulture in this scenario requires high levels of efficiency in the use of water, a scarce resource whose use is expected to be severely restricted in the near future. In this regard, the use of drought-tolerant varieties that are able to maintain grape yield and quality could be an effective strategy to face this change. During three consecutive seasons (2018-2020) the behavior in rainfed regime of 13 traditional red grapevine varieties of the Spain central region was studied. These varieties were cultivated in a collection at Centro de Investigación de la Vid y el Vino de Castilla-La Mancha (IVICAM-IRIAF) located in Tomelloso (Castilla-La Mancha, Spain). Yield components (yield, mean bunch and berry weight, pruning weight), physicochemical parameters of the musts (brix degree, total acidity, pH) and some physiological parameters related with water stress during ripening period (δ13C, δ18O) were analysed. The application of different statistical techniques to the results showed the existence of significant differences between varieties in their response to stressful conditions. A few varieties highlighted for their high ability to adapt to drought, being able to maintain high yields due to their efficiency in the use of water. In addition, it was possible quantify to what extent climate can be a determinant in the δ18O of musts under severe water stress conditions.

Climate change projections to support the transition to climate-smart viticulture

The Earth’s system is undergoing major changes through a wide range of spatial and temporal scales as a response to growing anthropogenic radiative forcing, which is pushing the whole system far beyond its natural variability. Sources of greenhouse gases largely exceed their sinks, thus leading to a strengthened greenhouse effect. More energy is thereby being supplied to the system, with inevitable shifts in climatic patterns and weather regimes. Over the last decades, these modifications have been manifested in the full statistical distributions of the atmospheric variables, with dramatic changes in the frequency and intensity of extremes. Natural hazards, such as severe droughts, floods, forest fires, or heatwaves, are being triggered by extreme atmospheric events worldwide, thus threatening human activities. Viticultculture is not only exposed to changing climates but is also highly vulnerable, as grapevine phenology and physiological development are strongly controlled by atmospheric conditions. Therefore, the assessment of climate change projections for a given region is critical for climate change adaptation and risk reduction in viticulture. By adopting timely and suitable measures, the future sustainability and resiliency of the sector can be fostered. Climate-grapevine chain modelling is an essential tool for better planning and management. However, the accuracy of the resulting projections is limited by many uncertainties that must be duly taken into account when transferring knowledge to stakeholders and decision-makers. Climate-smart viticulture will comprise ensembles of locally tuned strategies, envisioning both adaptation and mitigation, assisted by emerging technologies and decision-support systems.

Simulating climate change impact on viticultural systems in historical and emergent vineyards

Global climate change affects regional climates and hold implications for wine growing regions worldwide. Although winegrowers are constantly adapting to internal and external factors, it seems relevant to develop tools, which will allow them to better define actual and future agro-climatic potentials. Within this context, we develop a modelling approach, able to simulate the impact of environmental conditions and constraints on vine behaviour and to highlight potential adaptation strategies according to different climate change scenarios. Our modeling approach, named SEVE (Simulating Environmental impacts on Viticultural Ecosystems), provides a generic modeling framework for simulating grapevine growth and berry ripening under different conditions and constraints (slope, aspect, soil type, climate variability…) as well as production strategies and adaptation rules according to climate change scenarios. Each activity is represented by an autonomous agent able to react and adapt its reaction to the variability of environmental constraints. Using this model, we have recently analyzed the evolution of vineyards’ exposure to climatic risks (frost, pathogen risk, heat wave) and the adaptation strategies potentially implemented by the winegrowers. This approach, implemented for two climate change scenarios, has been initiated in France on traditional (Loire Valley) and emerging (Brittany) vineyards. The objective is to identify the time horizons of adaptations and new opportunities in these two regions. Carried out in collaboration with wine growers, this approach aims to better understand the variability of climate change impacts at local scale in the medium and long term.

Exploring resilience and competitiveness of wine estates in Languedoc-Roussillon in the recent past: a multi-level perspective

The Languedoc-Roussillon wineries are facing a decline in wine yields particularly PGI yields due to many factors. Climate change is just ones, but is expected to increase in the future. There is also structurally a large heterogeneity of yield profiles among terroirs, varieties and strategies. This work investigates the link between yield, competitiveness and resilience to explore how resilient winegrowers have been in the recent past. To this end two approaches have been combined; (i) an accountancy database analysis at estate scale and (ii) municipality level competitiveness analysis. A new resilience indicator that characterizes the capacity of an estate to absorb yield variation is also defined. The FADN database between 2000 and 2018 of ex-Languedoc-Roussillon (France) and other data are used to analyse the current situation and the past evolution of competitiveness and resilience by type of estate (type of farm: PGI and/or PDO & type of commercialization: bulk and/or bottles). The net margin, which defines competitiveness, is not correlated to yield for all types but depends on the type of commercialization and the level of specialisation. The resilience indicator shows that the net margin of estates specialized in PGI is particularly sensitive to yield declines. We also show that price evolutions seem to compensate the effect of yield losses for the majority of types. Municipality scale analysis shows the links between local pedoclimate, yield, commercialization strategies and price. Overlapping a PDO with a PGI does not always increase a municipality’s PGI competitiveness. It is difficult to make links between causes and effects due to the complexity of the wine production system. Production diversification may be a solution. Resorting to the two level of analysis helps resolving the data gap that is necessary to explore the links between yield and economic performance of the wine estates in the long term.

Grapevine sugar concentration model in the Douro Superior, Portugal

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65