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IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 ´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

Abstract

High-volume mass-market white wines production method by means of harvest-deferred fermentation from desulphited musts allows an efficient business management by avoiding the seasonality in wine sector. This technology has been used in the production of light and fresh wines from Vinhos Verdes Appellation (VVA – Portugal). This Appellation presents a diversity of varieties and wine styles, and is known for producing light and fresh wines, but also mineral, complex and structured ones, with, in general, low ethanol content. The light and fresh VV wines are characterized by herbaceous, citrus, tropical fruits, orchard fruits and floral notes. Thus, the goal of this work was to unveil based on physical-chemical data if sulphitated musts from VVA preserve the organoleptic potential that allows the production of high-volume wines with the typical light and fresh VV character. A set of musts were produced at industrial scale from grapes harvested from different sub-regions of VVA, which were then sulphited and stored for 1 year. For comparison purpose, sulphitated musts from Beira Atlântico and Trás-os-Montes Portuguese regions were also characterized. Free volatile and glycosidically-linked compounds were determined by advanced gas chromatography (GC×GC-ToFMS). The physical-chemical parameters currently used in musts quality control were also determined. Statistical tools were applied by combining all data domains. The aroma potential of musts was performed based on the construction of aroma networks [1].A total of 145 volatile compounds were putative identified, which varied from 136 to 142, in must from Cávado and Lima sub-regions, respectively. Regarding the glycosidically-linked fraction, 29 compounds were putatively identified, which varied from 20 to 24 in must from Cávado and Amarante sub-regions. Clustering analysis unveiled the formation of 3 main clusters, one of which includes all VVA musts, which allows to infer that geographical region is the main distinguishing factor. VVA musts were characterized with higher total acidity, and lower °Brix, potency alcoholic strength and density, compared with the samples from other regions. Moreover, esters, monoterpenic and sesquiterpenic compounds detected in VVA musts may contribute with citrus, floral, orchard and tropical fruits aromas, which are relevant aromas for sensory characteristics of VV wines. Thus, must sulphitation, a methodology used to extend its preservation beyond the harvest season, seems to keep the particular musts character, which is extremely important for the consistency of light and fresh high-volume VV wines.

Acknowledgments:

This work was funded under the project PRECIDIF – Precision Management of new Vinho Verde wines production from differential fermentation, project nº 24214. FCT/MEC for financial support LAQV-REQUIMTE (UIDB/50006/2020) through national funds and co-financed by the FEDER and PT2020.

References

[1] Y-Y Ahn, SE Ahnert, JP Bagrow, A-L Barabási, Flavor network and the principles of food pairing, Scientific reports (2011) 1, 196.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Rocha Silvia1, Martins Cátia1, Fontes Natacha2, Cunha e Silva Sara2 and Graça António2

1LAQV-REQUIMTE & Department of Chemistry, University of Aveiro
2Sogrape Vinhos, S.A.

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Keywords

white must sulphitation; free volatile compounds; glycosidically-linked compounds; physical-chemical parameters; aroma potential

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Terroir analysis and its complexity

Terroir is not only a geographical site, but it is a more complex concept able to express the “collective knowledge of the interactions” between the environment and the vines mediated through human action and “providing distinctive characteristics” to the final product (OIV 2010). It is often treated and accepted as a “black box”, in which the relationships between wine and its origin have not been clearly explained. Nevertheless, it is well known that terroir expression is strongly dependent on the physical environment, and in particular on the interaction between soil-plant and atmosphere system, which influences the grapevine responses, grapes composition and wine quality. The Terroir studying and mapping are based on viticultural zoning procedures, obtained with different levels of know-how, at different spatial and temporal scales, empiricism and complexity in the description of involved bio-physical processes, and integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling both the vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. In fact, this know-how is crucial for supporting the analysis of climate change impacts on terroir resilience, identifying new promised lands for viticulture, and driving vineyard management toward a target oenological goal. In this contribution, an overview of the last findings in terroir studies and approaches will be shown with special attention to the terroir resilience analysis to climate change, facing the use and abuse of terroir concept and new technology able to support it and identifying the terroir zones.

De novo Vitis champinii whole genome assembly allows rootstock-specific identification of potential candidate genes for drought and salt tolerance

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20-Year-Old data set: scion x rootstock x climate, relationships. Effects on phenology and sugar dynamics

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Using δ13C and hydroscapes as a tool for discriminating cultivar specific drought response

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The effects of alternative herbicide free cover cropping systems on soil health, vine performance, berry quality and vineyard biodiversity in a climate change scenario in Switzerland

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IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 ´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

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Evaluation of climate change impacts at the Portuguese Dão terroir over the last decades: observed effects on bioclimatic indices and grapevine phenology

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Aromatic maturity is a cornerstone of terroir expression in red wine

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austrianvineyards.com: online viewer of all designations of Austrian wine

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IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 ´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

´Vinho Verde´ wines production from differential fermentation: the role of musts sulphitation as a preservation strategy to keep the musts character

Abstract

Content of the article

References

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DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: typeofthepublication

Authors

author1, author2, author3

Presenting author

Description

List of affiliations ¹ ² ³

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Email address (with mailto: link)

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Using δ13C and hydroscapes as a tool for discriminating cultivar specific drought response

Measurement of carbon isotope discrimination in berry juice sugars at maturity (δ13C) provides an integrated assessment of water use efficiency (WUE) during the period of berry ripening, and when collected over multiple seasons can be used as an indication of drought stress response. Berry juice δ13C measurements were carried out on 48 different varieties planted in a common garden experiment in Bordeaux, France from 2014 through 2021 and were paired with midday and predawn leaf water potential measurements on the same vines in a subset of six varieties. The aim was to discriminate a large panel of varieties based on their stomatal behaviour and potentially identify hydraulic traits characterizing drought tolerance by comparing δ13C and hydroscapes (the visualisation of plant stomatal behaviour as a response to predawn water potential). Cluster analysis found that δ13C values are likely affected by the differing phenology of each variety, resulting in berry ripening of different varieties taking place under different stress conditions within the same year. We accounted for these phenological differences and found that cluster analysis based on specific δ13C metrics created a classification of varieties that corresponds well to our current empirical understanding of their relative drought tolerances. In addition, we analysed the water potential regulation of the subset of six varieties (using the hydroscape approach) and found that it was well correlated with some δ13C metrics. Surprisingly, a variety’s water potential regulation (specifically its minimum critical leaf water potential under water deficit) was strongly correlated to δ13C values under well-watered conditions, suggesting that base WUE may have a stronger impact on drought tolerance than WUE under water deficit. These results give strong insights on the innate WUE of a very large panel of varieties and suggest that studies of drought tolerance should include traits expressed under non-limiting conditions.

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

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.

Adaptability of grapevines to climate change: characterization of phenology and sugar accumulation of 50 varieties, under hot climate conditions

Climate is the major factor influencing the dynamics of the vegetative cycle and can determine the timing of phenological periods. Knowledge of the phenology of varieties, their chronological duration, and thermal requirements, allows not only for the better management of interventions in the vineyard, but also to predict the varieties’ behaviour in a scenario of climate change, giving the wine producer the possibility of selecting the grape varieties that are best adapted to the climatic conditions of a certain terroir. In 2014, Symington Family Estates, Vinhos, established two grape variety libraries in two different places with distinctive climate conditions (Douro Superior, and Cima Corgo), with the commitment of contributing to a deeper agronomic and oenological understanding of some grape varieties, in hot climate conditions. In these research vineyards are represented local varieties that are important in the regional and national viticulture, but also others that have over time been forgotten — as well as five international reference cultivars. From 2017 to 2021, phenological observations have been made three times a week, following a defined protocol, to determine the average dates of budbreak, flowering and veraison. With the climate data of each location, the thermal requirements of each variety and the chronological duration of each phase have been calculated. During maturation, berry samples have been gathered weekly to study the dynamics of sugar accumulation, between other parameters. The data was analysed applying phenological and sugar accumulation models available in literature. The results obtained show significant differences between the varieties over several parameters, from the chronological duration and thermal requirements to complete the various stages of development, to the differences between the two locations, confirming the influence of the climate on phenology and the stages of maturation, in these specific conditions.

Adapting the vineyard to climate change in warm climate regions with cultural practices

Since the 1980s global regime shift, grape growers have been steadily adapting to a changing climate. These adaptations have preserved the region-climate-cultivar rapports that have established the global trade of wine with lucrative economic benefits since the middle of 17th century. The advent of using fractions of crop and actual evapotranspiration replacement in vineyards with the use of supplemental irrigation has furthered the adaptation of wine grape cultivation. The shift in trellis systems, as well as pruning methods from positioned shoot systems to sprawling canopies, as well as adapting the bearing surface from head-trained, cane-pruned to cordon-trained, spur-pruned systems have also aided in the adaptation of grapevine to warmer temperatures. In warm climates, the use of shade cloth or over-head shade films not only have aided in arresting the damage of heat waves, but also identified opportunities to reduce the evapotranspiration from vineyards, reducing environmental footprint of vineyard. Our increase in knowledge on how best to understand the response of grapevine to climate change was aided with the identification of solar radiation exposure biomarker that is now used for phenotyping cultivars in their adaptability to harsh environments. Using fruit-based metrics such as sugar-flavonoid relationships were shown to be better indicators of losses in berry integrity associated with a warming climate, rather than solely focusing on region-climate-cultivar rapports. The resilience of wine grape was further enhanced by exploitation of rootstock × scion combinations that can resist untoward droughts and warm temperatures by making more resilient grapevine combinations. Our understanding of soil-plant-atmosphere continuum in the vineyard has increased within the last 50 years in such a manner that growers are able to use no-till systems with the aid of arbuscular mycorrhiza fungi inoculation with permanent cover cropping making the vineyard more resilient to droughts and heat waves. In premium wine grape regions viticulture has successfully adapted to a rapidly changing climate thus far, but berry based metrics are raising a concern that we may be approaching a tipping point.