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…

Changes in phenolic maturity and texture characteristics of the grape berry under pre-, and post-veraison water deficit

Kékfrankos (Vitis vinifera L.) grapevines grafted on Teleki-Kober 5BB rootstock were submitted to water deficit under greenhouse conditions.

Combined abiotic-biotic plant stresses on the roots of grapevine

In the 19th century, devastating outbreaks of phylloxera (Daktulosphaira vitifoliae Fitch), almost brought European viticulture to its knees. Phylloxera does not only take energy in form of sugars from the vine, but also affects the up- and down- regulations of genes, acts as a carbon sink and reprograms the physiology of the grapevines, including nutrient uptake and the defense system [1]. A key trait of rootstocks is the ability to perform well under high lime conditions as about 30 % of the land surface has calcareous soil. Iron deficiency not only causes the well-known problems of lime-induced chlorosis and stunted growth, but also affects the entire plant metabolism.

Stem growth disorder and xylem anatomy modifications during esca pathogenesis in grapevines

Esca is a grapevine vascular disease with detrimental consequences on vineyard yield and longevity. Recently, esca leaf symptom development has been shown to result in the occlusion of xylem vessels by tyloses in leaves and stems, leading to hydraulic failure. However, little is known regarding the response of xylem anatomy and stem growth to esca in different varieties . Here we studied the impact of esca leaf symptom development on grapevine physiology, stem growth, and xylem anatomy in two widespread cultivars, Cabernet sauvignon and Sauvignon blanc.

Design of an indicator of vine vigor potential conferred by soil (vipos), using a fuzzy expert system

Winegrowers must adapt more and more their viticultural practices in order to evolve toward a sustainable viticulture, to be competitive and to improve both the production methods and the quality and typicalness of wines. In this context, ‘Terroir’ studies in Loire Valley vineyards have allowed to build decision aid maps that can be used directly by growers to adjust their practices.

Observatoire Grenache en Vallée du Rhône: incidence du terroir sur la composition polyphénolique des raisins et des vins

The Grenache observatory was created in 1995. The object of this 24 parcels network, covering main Rhone Valley soils, is to state the effect of pedo-climatic conditions on plant physiology and wine characteristics. The results concerning colour and tanins show a very important diversity in Grenache behaviour.