Macrowine 2021
IVES 9 IVES Conference Series 9 Study of the colour and phenolic evolution of three different tannin/anthocyanin ratios over time in a model wine

Study of the colour and phenolic evolution of three different tannin/anthocyanin ratios over time in a model wine

Abstract

Phenolic compounds are important quality indicators in red wine. A large number of polyphenols play an important role in wine development, contributing to the colour and the sensory perception of the wines. Anthocyanins are the pigments responsible for the colour in young red wines while tannins are the principal contributors to the bitterness and the astringency of the wines. Wine polyphenols are considered more complex molecules than grape phenolics, due to the enormous number of chemical reactions which take place during the entire winemaking process and storage, forming more stable compounds. In theory, the tannin/anthocyanin ratio could affect the development of the phenolic profile of the wine. Oxygen also plays an essential part in wine’s colour and phenolic stabilization. The main aim of the study is to evaluate the colour and phenolic evolution over time of three different tannin/anthocyanin ratios in a model wine system as well as the impact that oxygen has on this. The three different tannin/anthocyanin ratios were selected according to a different volume of seeds: skins (Sk) with no seeds added, skins + seeds (SkS) and skins + 4 times seeds (Sk4S). The extractions took place in model wine solution. The three treatments were separated into two oxygen treatments and stored hermetically closed vials. Preliminary results show, as expected, a similar amount of anthocyanin in all the treatments and higher tannin concentration in the 4 time seeds treatment. Oxygen consumption also seemed to differ between the ratios. The colour and phenolic evolution will be reported at different sampling stages over time.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Gonzalo Garrido Bañuelos*, André De Villiers, Astrid Buica, Wessel du Toit

*Stellenbosch University

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Monitoring of Pesticide Residues from Vine to Wine

Those previous years, pesticides are often brought to the forefront by media. Questions arose about their toxicity for growers and consumers. Even if a downward trend is underway, the use of pesticides is required to ensure steady quality and quantity of harvests. A large number of active ingredients are authorized but regarding viticulture, mainly insecticides and fungicides are applied, to control pests and diseases and to increase crop yield. Some phytosanitary products, principally fungicides, applied close to the harvest date may frequently be detected in wines.

Anthropogenic factors in modulations of fungal populations from grapes to wines and their repercussions on wine characteristics

The effects of anthropogenic activities on vineyard (different plant protections) and in winery
(pressing/clarification step, addition of sulfur dioxide) on fungal populations from grape to wine were studied. The studied anthropogenic activities modify the fungal diversity. Thus, lower biodiversity of grapes from organic modality was measured for the three vintages considered compared to biodiversity from ecophyto modality and conventional modality. The pressing / clarification steps strongly modify fungal populations and the influence of the winery flora is highlighted.

Study of the volatil profile of minority white varieties

The genetic material preservation is a priority issue in winemaking research. The recovery of minority grape varieties can control the genetic erosion, contributing also to preserve wine typical characteristics. In D.O.Ca. Rioja (Spain) the number of grown white varieties has been very limited, representing Viura the 91% of the cultivated white grape area in 2005, while the others, Garnacha Blanca and Malvasía riojana, hardly were grown. For this reason, a recovery and characterization study of plant material was carried out in this region. In 2008, the results obtained allowed the authorization of three minority white varieties: Tempranillo Blanco, Maturana Blanca and Turruntés.

Characterization of non-Saccharomyces yeast and its interaction with Saccharomyces cerevisiae with investigation of fermentation kinetics and aromatic composition

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Analysis of peptide fraction from white wines

Among nitrogen compounds included in white wines, the peptide fraction is certainly the least studied, however this fraction is quantitatively the most important (Feuillat, 1974). Existing studies concern the fraction below 1 kDa and only for white and sparkling wines (Bartolomé et al, 1997, Desportes et al 2000). In this report, we have developed methods to isolate peptides from reference white wines. Then, we have applied this methodology with bitter wine to answer a research question: is there a relation between peptides and the bitterness of white wine as for some cheese for example (Furtado, 1984)?