OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Wine tannins: What place for grape seed?

Wine tannins: What place for grape seed?

Abstract

Phenolic compounds are among the most important quality factors of wines. They contribute to the organoleptic characteristics of wine such as colour, astringency, and bitterness. Although tannins found in wine can come from microbial and oak sources, the main sources of polyphenols are skin and seed from grapes. Yet, the link between grape seed phenolic content and wine composition, or even the link between seed maturity stage and wine composition are poorly studied. This work describes and explains the seed tannins kinetics release in wine, but also the impact of seed maturity stage on seed tannins extractability. 

The polyphenol content and composition of seeds at three different grape maturity stages were characterized (fifteen days before harvest, harvest and fifteen days after harvest). After that, an original approach of nanovinification was conducted. At each maturity stages three winemaking modalities have been produced in duplicate: (i) a control modality, (ii) a seed modality made of exclusively with seed and (iii) a skin modality made of exclusively with skin. The evolution of seed tannins release and tannins wine content has been followed during the winemaking, from alcoholic fermentation to maceration. 

Independently from the grape maturity stage, skin tannins are present at the first step of winemaking contrarily to seed tannins presence which is progressive all along the vinification. The results indicated that (+)-catechin is the less extractable free flavan-3-ols compared to (-)-epicatechin and (-)-epicatechin gallate. Furthermore the mean degree of polymerization of seed proanthocyanidins seems to be directly linked to their extractability, raising the question of the impact of tannins interaction and cellular location on tannins extractability.

DOI:

Publication date: June 23, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Pauline Rousserie, Soizic Lacampagne, Sandra Vanbrabant, Amélie Rabot, Laurence Geny-Denis

Institut des Sciences de la Vigne et du Vin 210 Chemin de Leysotte 33140 VILLENAVE D’ORNON, France 

Contact the author

Keywords

Grape Maturity, Tannins, Extraction, Seed 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Isotopes to distinguish production system in Brazilian viticulture

Organic viticulture integrates practices aimed at foresting positive relationships among, vines, soil, and climate, with a focus on sustainability, social responsibility, and environmental protection. To safeguard production integrity, regulatory bodies worldwide conduct organic certifications in accordance with relevant regulations. Considering that agriculture practices influence the nitrogen, carbon and oxygen isotope composition, the study aimed to investigate the response of these isotopes in grape must cultivated by organic, biodynamic and conventional methods to distinguish between production systems.

Influenza del sito di coltivazione nella espressione aromatica del Moscato liquoroso di Pantelleria

ln 1997, twenty six cultivation sites of cv. Muscat of Alexandria different for pedological conditions, altitude and exposition were selected through ail Pantelleria isle. ln each site, described and classified according to USDA Soil Taxonony and FAO Soil Classification methods, grapes, collected at technological ripening, were microvinificated, following a standard procedure which allowed to obtain the naturally sweet wine DOC Moscato di Pantelleria. Wines, five months after vinification, were analysed by gaschromatography.

Development of a novel UAV based approach for assessing the severity of spring frost and hail damages in vineyards

A solid feature of climate change is that the frequency and severity of weather extremes are increasing. Ranking European countries for the number of crop failures related to extreme events reports France on top followed by Italy and Spain (COM 2021).

Modeling the suitability of Pinot Noir in Oregon’s Willamette Valley in a changing climate

Air temperature is the key driver of grapevine phenology and a significant environmental factor impacting yield and quality for a winegrape growing region. In this study the optimal downscaled CMIP5 ensemble for computing thegrowing season average temperature (GST) viticulture climate classification index was determined to spatially compute on a decadal basis predictions of the GST climate index and the grapevine sugar ripeness (GSR) model for Pinot Noir throughout the Willamette Valley (WV) American Viticultural Area (AVA). Forecasts for average temperature and a 220 g/L target sugar concentration level were computed using daily Localized Constructed Analogs (LOCA) downscaled CMIP5 historic and Representative Concentration Pathways (RCP) future climate projections of minimum and maximum daily temperature. We explore spatiotemporal trends of the GST climate classification index and Pinot Noir specific applications of the GSR phenology model for the WV AVA. Spatiotemporal computations of the GST climate index and Pinot Noir specific applications of the GSR model enable the opportunity to explore relationships between their computed values with one intent being to provide updated GST ranges that better align with current temperature-based modeling understanding of Pinot Noir grapevine phenology and the viticultural application of LOCA CMIP5 climate projections for the WV AVA. The Pinot Noir specific applications of the GSR model or the GST index with updated bounds indicate that the percent of the WV AVA area suitable for Pinot Noir production is currently at or near its peak value in the upper 80s to lower 90s of this century.

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.