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…

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.

Upscaling the integrated terroir zoning through digital soil mapping: a case study in the Designation of Origin Campo de Borja

homogeneous zones by intersecting several partial zonings of major factors that influence vineyard growth. Each of them follows specific process from their corresponding disciplines. Soil zoning specifically refers to a Soil Resource Inventory map that has traditionally been generated by conventional soil mapping methods. These methods have shortcomings in reaching fine cartographic and categorical details and involve significant expenses, which undermines their applicability. A new framework named Digital Soil Mapping has introduced quantitative models by statistical techniques to establish soil-landscape relationships and is able to provide intensive scale cartography.

In the present study, a microzoning at 1:10.000 scale is generated from an initial zoning, where the conventional soil map with polytaxic map units is replaced by a new one from digital techniques that disaggregates them. The comparison between the zonings considers a quantitative evaluation of capability for each Homogeneous Terroir Unit by means of the Viticultural Quality Index and its categorization based on its distribution by map. The spatial intersection of both maps gives rise to a confusion matrix in which the flows of class variations after the substitution are assessed.

The results show a five-fold increase in the number of Homogeneous Terroir Units identified and a larger differentiation among them, evidenced by a wider range in the capability index distribution. Both elements are accompanied by an increase in the detection of areas of higher potential within previously undervalued uniform zones.These features are a direct effect of the improvements brought by Digital Soil Mapping techniques and would verify the advantages of their implementation in the Integrated Terroir zoning. Eventually, such new highly detailed terroir units would benefit precision viticulture and sustainable management practices.

Influence of climatic conditions on grape composition of Tempranillo in La Mancha DO (Spain)

The aim of this work was to analyze the variability in grape composition of the Tempranillo cultivar related to climatic conditions, in La Mancha Designation of Origin. Grape composition (sugar content, total acidity, pH, malic acid, and total and extractable anthocyanins) recorded during ripening, were analysed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The relationships between grape parameters with climatic variables related to temperature and to water deficits, referring different periods between phenological events along the growing cycle, were evaluated using regression analysis. High variability in grape composition was observed in the period analysed. Total acidity varied between 3.7 and 7.3 gL-1 while malic acid varied between 1.2 and 4 gL-1. The extractable anthocyanins ranged between 526 and 972 mgL-1, and total anthocyanins ranged between 922 and 1388 mgL-1, being the lowest values recorded in the hottest year (2017). Total acidity decreased 0.77 gL-1 for an increase of 100 GDD, while malic acid decrease in 0.42 gL-1 for the same GDD increase, being the period between veraison and harvest the one that seemed to have higher influence on acidity. In addition, it was confirmed that increasing water deficits decreased acidity. Total and extractable anthocyanins increased in about 210 and 105 mgL-1, respectively, with an increase of 100 GDD from veraison to harvest, and the increase in water deficits favour the increase of anthocyanins, both total and extractable anthocyanins. Total and extractable anthocyanins concentration increased in 35 and 22 mgL-1 per an increase of 10 mm in the water deficit. These results can be of interest to understand the potential changes that grapes composition may suffer under future warmer climates.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Climate change impacts on Douro Region viticulture and adaptation measures

Climate has a significant impact in the success of any agricultural system, with a direct influence on the crops suitability to a given region, interfering on yield and quality and also with the economic sustainability of the productive activity. In the Douro Demarcated Region (RDD), as in most regions of the Mediterranean climate, the scarce precipitation (33% has less than 600 mm per year), and your high variability, associated with high rates of evapotranspiration during the summer, is usually one of the fundamental factors that limit the grapevine development, as well as the production and quality of the harvest. Thus, facing the scenario in temperature changes for the next decades (1.5-2.5°C) and confirming the predictions of precipitation decreases and/or great variability in the occurrence of heat waves and intense rainfall, the consequences for slope stability in mountain viticulture and sustainability of all operations involved, are risks to be taken into account. In this way, a deepest and sustained knowledge regarding the adaptation measures to adverse environmental conditions is of a crucial importance, enabling a more efficient adaptation of plant growth conditions and the optimization of production and quality of the grapevines. The development of this work, carried out in two commercial vineyards, one located in Soutelo do Douro, São João da Pesqueira, Cima Corgo sub-region, and another located in Numão, Vila Nova de Foz Côa, Douro Superior sub-region, it seeks to establish a relationship between climatic elements and physiological, productive and qualitative parameters, as well as to evaluate the effectiveness of adaptation measures, including different types of deficit irrigation (2002-2019) and the application of shading nets (2019-2020) in the physiological, viticultural and oenological behavior in the Touriga Nacional and Moscatel Galego Branco varieties, respectively. The results showed that the application of deficit irrigation allowed to significantly reduce the impact of the adverse weather conditions at key moments in the development of the grapevine, particularly in the period immediately before veráison and maturation, reducing the negative effects on the physiological processes and productivity, without compromise the must quality parameters. On the other hand, the application of shading nets significantly reduced de leaves temperature, allowing to increase the water potential, stomatal conductance and photosynthetic rate of grapes, which was reflected in the yield increase in the 2nd year of the study. For the maturation indicators, higher levels of total acidity, malic acid and assimilable nitrogen were obtained. The last measure presents a huge potential, being essential to carry out more years of trials to obtain stronger conclusions in terms of production parameters, but also in characteristics as important as the grape ripening components and the organoleptic characteristics of wines.