Macrowine 2021
IVES 9 IVES Conference Series 9 Anthocyanins in tannat wines rapidly evolve toward unidentified red-coloured pigments

Anthocyanins in tannat wines rapidly evolve toward unidentified red-coloured pigments

Abstract

AIM: To assess the relationship between the reported low-stability of Tannat colour during wine storage and its pigment composition and evolution

METHODS: Twenty wines were elaborated under experimental conditions over two vintages, 2015 and 2016, eight corresponding to Tannat, and six to Syrah and Marselan. Wines were stored in darkness under cellar temperature conditions. Anthocyanins and tannins were quantified by spectrophotometric methods as well as by HPLC-DAD-ESI-MSn. Analysis were made three months after the end of winemaking, and twelve and twenty-four months later.

RESULTS: At three months, the pigment content determined by HPLC (spectrophotometer) ranged between 190-240 mg/L (370-665 mg/L) in Tannat, 200-320 mg/L (420-470) in Marselan and 100-305 (220-340) in Syrah. Colour intensity was between 17-28 AU in Tannat, 15-17 in Marselan and 10-16 in Syrah. From the second analytical date on, Tannat wines registered the lowest HPLC/spectrophotometer anthocyanin quotient, tendency increasing with wine age. Besides, Tannat wines presented much higher decreases of the HPLC anthocyanin content between analytical dates than the observed in Marselan and Syrah. This was independent from the type of pigment considered. Moreover, the unresolved HPLC broad peak was also of a higher relative magnitude in Tannat wines. This could not be explained by the tannin contents or pH measured in the wines. Spectrophotometric anthocyanin results did not show such differences among cultivars, neither in the proportion of SO2 bleachable pigments. Tannat wines showed as well the highest colour intensity decreases through time.

CONCLUSIONS

The result suggests that in Tannat wines, anthocyanins may evolve rapidly towards polymeric pigments that would still have red-bluish hues but would be less stable. These findings could be behind the low colour stability reported in literature for Tannat wines, and could be a starting point for future research.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Guzmán Favre

Faculty of Agronomy, Universidad de la República, Av. Garzón 780. C.P., 12900 Montevideo, Uruguay ,Sergio, GÓMEZ-ALONSO, Regional Institute of Applied Scientific Research (IRICA), University of Castilla-La Mancha, Avda. Camilo José Cela S / N, 13071 Ciudad Real, Spain. José, PÉREZ-NAVARRO, Regional Institute of Applied Scientific Research (IRICA), University of Castilla-La Mancha, Avda. Camilo José Cela S / N, 13071 Ciudad Real, Spain. Diego, PICCARDO, Faculty of Agronomy, Universidad de la República, Av. Garzón 780. C.P., 12900 Montevideo, Uruguay  Gustavo, GONZÁLEZ-NEVES, Faculty of Agronomy, Universidad de la República, Av. Garzón 780. C.P., 12900 Montevideo, Uruguay

Contact the author

Keywords

colour stability and evolution, derived pigments, tannat, syrah, marselan

Citation

Related articles…

Genotypic variability in root architectural traits and putative implications for water uptake in grafted grapevine

Root system architecture (RSA) is important for soil exploration and edaphic resources acquisition by the plant, and thus contributes largely to its productivity and adaptation to environmental stresses, particularly soil water deficit. In grafted grapevine, while the degree of drought tolerance induced by the rootstock has been well documented in the vineyard, information about the underlying physiological processes, particularly at the root level, is scarce, due to the inherent difficulties in observing large root systems in situ. The objectives of this study were to determine genetic differences in the root architectural traits and their relationships to water uptake in two Vitis rootstocks genotypes (RGM, 140Ru) differing in their adaptation to drought. Young rootstocks grafted upon the Riesling variety were transplanted into cylindrical tubes and in 2D rhizotrons under two conditions, well watered and moderate water stress. Root traits were analyzed by digital imaging and the amount of transpired water was measured gravimetrically twice a week. Root phenotyping after 30 days reveal substantial variation in RSA traits between genotypes despite similar total root mass; the drought-tolerant 140Ru showed higher root length density in the deep layer, while the drought-sensitive RGM was characterised by shallow-angled root system development with more basal roots and a larger proportion of fine roots in the upper half of the tube. Water deficit affected canopy size and shoot mass to a greater extent than root development and architectural-related traits for both 140Ru and RGM, suggesting vertical distribution of roots was controlled by genotype rather than plasticity to soil water regime. The deeper root system of 140Ru as compared to RGM correlated with greater daily water uptake and sustained stomata opening under water-limited conditions but had little effect on above-ground growth. Our results highlight that grapevine rootstocks have constitutively distinct RSA phenotypes and that, in the context of climate change, those that develop an extensive root network at depth may provide a desirable advantage to the plant in coping with reduced water resources.

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

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

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.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.