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IVES 9 IVES Conference Series 9 Evaluation des aptitudes œnologiques des raisins rouges avec l’étude de certains nouveaux indices de maturité phénolique

Evaluation des aptitudes œnologiques des raisins rouges avec l’étude de certains nouveaux indices de maturité phénolique

Abstract

Pour obtenir des vins d’une certaine gamme, il faut connaître les paramètres liés à la composition de la baie et introduire non seulement les paramètres classiques, c’est-à-dire sucres et acidité, mais aussi les paramètres qui tiennent compte des aspects jusqu’ici sous-estimés comme la composition en substances phénoliques.
On distingue trois degrés de maturité: une maturité technologique qui est jugée d’après la teneur en sucre et en acidité et qui est souvent utilisée car elle permet d’établir facilement la date des vendanges; une maturité phénolique qui tient compte du contenu d’anthocyanes dans la pellicule pendant la maturation du raisin, pour pouvoir déterminer ce paramètre, les méthodes d’analyse nécessaires sont lentes (et donc difficile à appliquer pendant les vendanges) en outre la teneur élevée en anthocyanes ne garantit pas toujours un vin coloré; une maturité cellulaire, paramètre en relation avec le degré de dégradation des parois cellulaires de la pellicule du raisin, c’est-à-dire la facilité d’extraction des pigments; malheureusement cette analyse a elle aussi besoin d’un certain temps.
Il en dérive que la connaissance de plusieurs paramètres (sucres, acides organiques, polyphénols et arômes) et des indices de maturation qui les complètent, permet de distinguer plus clairement l’époque optimale des vendanges, en fonction du type de vin que l’on souhaite obtenir (2, 5, 7, 8, 12, 13, 14, 16).
De récentes recherches ont pris en considération la nécessité d’établir l’époque optimale de la récolte du raisin, sur la base des paramètres traditionnels, parmi lesquels il y a aussi la teneur en polyphénols.
L’étude de la composition polyphénolique des raisins a été affrontée par de nombreux auteurs, surtout pour les raisins rouges, vu l’influence positive exercée sur les caractéristiques organoleptiques.
L’objectif de cette recherche est de proposer de nouveaux indices pour étudier la maturité phénolique des raisins rouges qui, en ajout ou en remplacement des indices déjà proposés par d’autres auteurs (1, 10, 11, 15), permettent une meilleure estimation du raisin dans le but d’en définir la qualité réelle et la potentialité œnologique. La présente recherche a pour but en outre de fournir une aide aux instruments de zonage viticole surtout pour les regions intéressées par la culture de raisins rouges (3).

DOI:

Publication date: February 24, 2022

Issue: Terroir 2000

Type: Article

Authors

Celotti E., Franceschi D. and Giulivo C.

Scuola Diretta a Fini Speciali in tecnica Enologica, Università di Padova, sede di Conegliano, Viale XXVIII Aprile 22, 31015 Conegliano/TV/Italie

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IVES Conference Series | Terroir 2000

Citation

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