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IVES 9 IVES Conference Series 9 Effet de l’ombrage respectif des ceps et des grappes de Muscat sur leurs teneurs en composés volatils libres et glycosyles et en précurseurs d’aromes carotenoïdiques

Effet de l’ombrage respectif des ceps et des grappes de Muscat sur leurs teneurs en composés volatils libres et glycosyles et en précurseurs d’aromes carotenoïdiques

Abstract

Le Muscat de Frontignan est bien connu pour ses fortes teneurs en composés terpéniques et par l’odeur florale et fruitée que ces composés confèrent aux vins qui en sont issus (1,2). Son potentiel aromatique est constitué de composés volatils odorants mais aussi de précurseurs d’arômes de nature glycosidique (3). Ces derniers sont présents en quantité supérieures aux composés libres dans le raisin et le vin. Ils ne deviendront odorant qu’après libération de la partie aglycone par hydrolyse de la liaison qui les lie aux sucres (4).
L’effet de l’ensoleillement sur les activités métaboliques est complexe. La photosynthèse est en général accélérée, et cette augmentation d’activité s’accompagne d’une modification des teneurs des pigments photosynthétiques rencontrés dans les tissus verts des végétaux supérieurs (5,6). Parmi eux les caroténoïdes, dont la synthèse est photo-induite, sont considérés comme les précurseurs des C13-norisoprénoïdes, composés aux propriétés odorantes intéressantes (7,8). Ces derniers sont également présents dans le raisin et le vin.
Le millésime a un effet sur les teneurs en caroténoïdes des baies mures (9). L’effet de l’ombrage sur les teneurs en caroténoïdes des baies a déjà été étudié (10,11). Il a été montré que l’ensoleillement augmentait les teneurs en caroténoïdes dans les baies de raisin vertes et accélérait leur dégradation pendant la phase de maturation, ceci pourrait se traduire par de plus fortes teneurs en C13-norisoprénoïdes dans les baies mures soumises à l’ensoleillement (12). D’autres travaux ont permis de démontrer l’effet du climat et du microclimat de la grappe sur les teneurs en monoterpènes libres et liés de cette dernière (13,14,15,16). Mais ces diverses études n’ont pas pris en compte l’effet de l’ombrage respectif des grappes seules d’une part, et de la totalité de la couronne aérienne d’autre part sur les composés de l’arôme. C’est le but de ce travail.

DOI:

Publication date: February 24, 2022

Issue: Terroir 2000

Type: Article

Authors

Alain RAZUNGLES, Sylvie BUREAU and Raymond BAUMES

Unité de Recherche Biopolymères et Arômes ​ENSA M INRA
2 Place Pierre Viala – Montpellier 34060 Cedex 1

Tags

IVES Conference Series | Terroir 2000

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