Terroir 2010 banner
IVES 9 IVES Conference Series 9 Différenciation de parcelles de Chenin du Val de Loire, a l’aide de l’etude des flores fongiques des raisins, en utilisant l’outil DGGE

Différenciation de parcelles de Chenin du Val de Loire, a l’aide de l’etude des flores fongiques des raisins, en utilisant l’outil DGGE

Abstract

Depuis le millésime 2002, une étude est menée sur la diversité de la flore fongique de parcelles du cépage chenin, situées essentiellement sur les appellations de Vouvray et Montlouis ; deux appellations séparées par le fleuve nommé la Loire. Les parcelles se situent dans des conditions pédoclimatiques différentes, qui se retrouvent au travers des suivis de maturité et l’état sanitaire.

L’objectif est d’utiliser la flore fongique comme facteur de différenciation entre les parcelles, et d’évolution au cours de la maturité. C’est dans ce cadre qu’un outil d’écologie microbienne a été utilisé : Denaturating Gradient Gel Electrophoresis (DGGE). Après une étude spécifique sur les moisissures des raisins, qui ont permis d’établir le référentiel, les échantillons complexes constitués de l’eau de lavage des baies de raisins, ont été analysés. Ainsi, nous avons pu analyser et différencier plusieurs parcelles de cépage chenin, situées dans des conditions pédoclimatiques différentes.

English version: Since the vintage wine 2002, a study is led on the variety of the fungal flora of parcels of the Chenin vine, situated essentially on the controlled origin label of Vouvray and Montlouis; two controlled origin label separated by the river named the Loire. The parcels are situated in conditions different of soils and of climate, which meet through the follow-ups of maturity and the sanitary state.

The objective is to use the fungal flora as factor of differentiation between the parcels, and evolution during the maturity. It is in this frame that a tool of microbial ecology was used: Denaturing Gradient Gel Electrophoresis (DGGE). PCR-DGGE is a molecular method which allows the direct analysis of DNA in complex samples without any culture step. This method is based on the separation in a denaturing gradient of double-strand DNA fragments which have the same length but different nucleotide sequences. After a specific study on fungus of grapes, which allowed establishing the reference table, the complex samples constituted by some water of wash of the berries of grapes, were analyzed. This tool will allow us to draw a parallel between the dynamic of fungal populations present in different conditions of soil and of climate. PCR-DGGE showed its potentialities for a fast characterization of fungi in complex mixes.

DOI:

Publication date: October 8, 2020

Issue: Terroir 2010

Type: Article

Authors

L. Guérin (1), M.Bouix (2), P. Poupault (1), R. Laforgue (1), P. Mallier (3), A. Mallet (3), J. Dupont (4)

(1) IFV Tours, 46 avenue Gustave Eiffel, 37100 Tours, France
(2) AgroParistech, Département de microbiologie industrielle, 1 avenue des Olympiades, 91744 Massy Cedex, France
(3) Chambre d’Agriculture d’Indre et Loire, 38 rue Augustin Fresnel, 37170 Chambray les Tours, France
(4) Muséum National d’Histoire Naturelle, Département Systématique et Evolution – Mycologie, 75005 Paris Cedex 05, France

Contact the author

Tags

IVES Conference Series | Terroir 2010

Citation

Related articles…

Overall conceptual characterization of aged dry white wines using a mental descriptive questionnaire

The purpose of the present study was to understand the overall concept of an aged dry white wine using a descriptive mental questionnaire. A total of 680 worldwide participants, grouped according to their involvement in the wine business, replied to an online questionnaire to characterize the sensory analytical and synthetic descriptors of an aged dry white wine. The descriptors were selected using a Check-All-That-Apply (CATA) approach concerning wine colour, aroma, taste, mouthfeel, and global appreciation.

Bunch placement effects on dehydration kinetics and physico-chemical composition of Nebbiolo grapes

Sforzato di Valtellina DOCG is a special reinforced red wine produced using withered Nebbiolo grapes. The withering process takes place in traditional rooms under natural environmental conditions; it starts immediately after the harvest and ends not before the 1st December of the same year. The process can be performed with different bunch placements that can influence the grapes features.The purpose of the study is to compare the effect on grape physico-chemical parameters for four withering bunch placement systems: hanged clusters (HC), plastic crates (CT), breathable mesh fabric on wooden frames panels (MF), and reed mats (RM). For all the systems studied, the withering length was two months at a temperature between 6 and 19 °C and a relative humidity of 41-88%.

2-YEARS STUDY ON COMPARISON BETWEEN THE VOLATILE CHEMICAL PROFILE OF TWO DIFFERENT BLENDS FOR THE ENHANCEMENT OF “VALPOLICELLA SUPERIORE”

Valpolicella is a famous wine producing region in the province of Verona owing its fame above all to the production of two Protected Designation of Origins (PDOs) withered wines: Amarone and Recioto. In recent years, however, the wineries have been interested in the enhancement and qualitative increase of another PDO, Valpolicella Superiore. All the Valpolicella PDOs wines are produced with a unique grape blend, mainly Corvina, Corvinone, Rondinella and a range of other minor varieties.From 2019 Valpolicella product regulation has changed the grape proportion of the blend allowing new composition parameters of wines. For this reason, studying the volatile chemical profiles to support wine makers in the effort to produce high quality wines represents a field of great interest.

Defining the terroir of the Columbia gorge wine region, Oregon and Washington, USA using geographic information systems (GIS)

The Columbia Gorge Wine Region (CGWR) extends for about 100km along the Columbia River and includes the Columbia Gorge American Viticultural Area (AVA) and the southwest portion of the Columbia Valley AVA.

Comparison of tannin analysis by protein precipitation and normal-phase HPLC

Tannins are a heterogenous class of polymeric phenolics found in grapes, oak barrels and wine. In red wine tannins are primarily responsible for astringency, though they also have an important role in reacting with and stabilizing pigments. There are numerous sub-classes of tannins found in wine but they all share structural heterogeneity within each sub-class, with varied polymer composition, configuration and length.

Numerous methodologies exist for the quantification of tannins, however, protein precipitation using bovine serum albumin has proved itself useful due to its strong correlation to the sensory perception of astringency and the basic instruments required for the method. Though the method can yield valuable insights into tannin composition, it cannot be automated easily and necessitates well-trained personnel.