IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Anthocyanins Chemistry During Red Wine Ageing

Anthocyanins Chemistry During Red Wine Ageing

Abstract

Anthocyanins are the main pigments present in young red wines, being responsible for their intense red color. These pigment in aqueous solutions occur in different forms in equilibrium that are dependent on the pH. At low pH values, anthocyanins are present in their red flavylium cation form but when the pH increases for values between 3 and 6, the flavylium cation form is hydrated yielding to the colorless hemiketal form that is in equilibrium with the pale yellow cis-chalcone form through tautomerization. Simultaneously, the flavylium cation is deprotonated to the respective violet neutral quinoidal base that at higher pH values can be deprotonated yielding the blue anionic quinoidal base. At wine pH (3-4), anthocyanin would be expected to be present mainly in their non-colored hemiketal form. However, the flavylium cation is the main form present in red wines. This is the result of its stabilization by different co-pigmentation mechanisms such as self-association and interaction with other wine components. Oligomeric anthocyanins (dimeric and trimeric) were also found to occur in red grapes and respective wines. Moreover, it was showed that trimeric anthocyanins reactivity is strongly dominated by acid-base chemistry, with the reaction sequence hydration – tautomerization – isomerization accounting less than 10% of the overall reactivity, which seems to indicate that polymerization may be a natural stabilization mechanism for the red color of anthocyanins. In addition, throughout wine ageing and maturation, the concentration of anthocyanins decreases dramatically and a color change is observed from red/violet to a more brick hue due to the formation of several anthocyanin-derivatives such as A and B-type vitisins and other pyranoanthocyanins that have been described in the literature over the years. Those compounds formed present a more stable color than their precursors (anthocyanins).  During this process, anthocyanins can yield polymeric pigments by their reaction with flavanols (directly or mediated by aldehydes). Moreover, it has been demonstrated that A-type vitisins (the main pyranoanthocyanins found in red wines) can also react with other wine components giving origin to polymeric pigments with different colors ranging from yellow to turquoise blue. Polymeric pigments are described to play an important role in the long-term color stability of aged red wines, however there is still a lot to know about their identity, chemical pathways and real contribution to the color displayed by red wines.

 Apart from the chromatic features that anthocyanins and anthocyanin-derived pigments are able to confer to red wines, it has also been demonstrated that this pigments can be involved in astringency and bitterness perception of red wines.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Joana Oliveira1

1LAQV – REQUIMTE – Department of Chemistry and Biochemistry of Faculty of Science of University of Porto, Rua do Campo Alegre S/N, 4169-007 Porto, Portugal

Contact the author

Keywords

Anthocyanins; chemistry; red wine ageing; anthocyanin-derived pigments; organoleptic properties

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Grapevine yield-gap: identification of environmental limitations by soil and climate zoning in Languedoc-Roussillon region (south of France)

Grapevine yield has been historically overlooked, assuming a strong trade-off between grape yield and wine quality. At present, menaced by climate change, many vineyards in Southern France are far from the quality label threshold, becoming grapevine yield-gaps a major subject of concern. Although yield-gaps are well studied in arable crops, we know very little about grapevine yield-gaps. In the present study, we analysed the environmental component of grapevine yield-gaps linked to climate and soil resources in the Languedoc Roussillon. We used SAFRAN data and IGP Pays d’Oc wine yields from 2010 to 2018. We selected climate and soil indicators proving to have a significant effect on average wine yield-gaps at the municipality scale. The most significant factors of grapevine yield were the Soil Available Water Capacity; followed by the Huglin Index and the Climatic Dryness Index. The Days of Frost; the Soil pH; and the Very Hot Days were also significant. Then, we clustered geographical zones presenting similar indicators, facilitating the identification of resources yield-gaps. We discussed the number of zones with the experts of IGP Pays d’Oc label, obtaining 7 zones with similar limitations for grapevine yield. Finally, we analysed the main resources causing yield-gaps and the grapevine varieties planted on each zone. Mapping grapevine resource yield-gaps are the first stage for understanding grapevine yield-gaps at the regional scale.

Effect of vigour and number of clusters on eonological parameters and metabolic profile of Cabernet Sauvignon red wines

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

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.