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IVES 9 IVES Conference Series 9 Influence de l’ensoleillement sur la composante aromatique des baies de raisin

Influence de l’ensoleillement sur la composante aromatique des baies de raisin

Abstract

La Syrah est un raisin à expression aromatique faible. Ce cépage atypique en tant que fruit permet l’élaboration de vins de grande réputation pour lesquels la particularité aromatique joue un rôle important. L’arôme variétal est constitué de substances volatiles directement perceptibles par la muqueuse olfactive et de précurseurs d’arôme, dont les glycosides constituent une classe importante. Ces derniers, des molécules inodores, sont en effet susceptibles, lors de la vinification, de donner naissance à des composés volatils et odorants participant à l’arôme du vin. Dans les baies de raisin de nombreux cépages et en l’occurrence dans la Syrah, les teneurs en glycosides sont nettement supérieures à celles des constituants volatils libres (Gunata et al., 1985 et Parle et al., 1991), ce qui montre l’importance des glycosides en terme de potentiel aromatique. Les glycosides peuvent être classés, en fonction de leur aglycone, par familles distinguant ainsi les composés en C6, les alcools, les phénols, les terpénols, les C13-norisoprénoïdes…Ces derniers, d’un grand intérêt olfactif, ont été identifiés dans le raisin et le vin (Strauss et al., 1987; Abbott, 1989). Dans les vins de Syrah, souvent caractérisés par une note de violette, les C13-norisoprénoïdes doivent contribuer fortement à l’arôme. En effet, parmi les composés les plus connus de la famille des Ci3-norisoprénoïdes, la β-ionone présente cette odeur de violette. L’importance des C13-norisoprénoïdes du point de vue de leur diversité olfactive et de leur teneur dans la fraction glycosylée de Syrah, nous a conduit à nous intéresser à leurs précurseurs, les caroténoïdes (Enzeil, 1985 ; Williams et al, 1992 ; Winterhalter, 1993). La teneur en caroténoïdes, relativement importante dans les baies vertes, diminue au cours de la maturation des baies (Razungles et al., 1988), ce qui laisse supposer que les C13-norisoprénoïdes trouvés dans les vins sont issus de ce catabolisme (Marais et al., 1991 ; Razungles et al., 1993). Les C13-norisoprénoïdes ont en effet le comportement inverse puisqu’ils augmentent avec la maturation des baies. L’importance du climat et du millésime sur la teneur en caroténoïdes et en arômes dans les baies a été montrée (Razungles et al., 1987 ; Marais et al., 1991 ; 1992). Nous nous sommes plus particulièrement intéressés dans ce travail à l’influence de l’éclairement des baies.

DOI:

Publication date: March 25, 2022

Issue: Terroir 1996

Type : Poster

Authors

S. BUREAU (1), A. RAZUNGLES (1), R. BAUMES (2), C. BAYONOVE (2)

(1) Institut Supérieur de la Vigne et du Vin, ENSAM- UFR de Technologie Oenologie
(2) Institut Supérieur de la Vigne et du Vin, INRA- Unité de Recherches sur les Arômes et Substances Naturelles – 2, Place Viala 34060 Montpellier cedex 1 France

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IVES Conference Series | Terroir 1996

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