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IVES 9 IVES Conference Series 9 The effect of terroir zoning on pomological, chemical and aromatic composition of Muscat d’Alexandrie grapevine variety cultivated in Tunisia

The effect of terroir zoning on pomological, chemical and aromatic composition of Muscat d’Alexandrie grapevine variety cultivated in Tunisia

Abstract

[English version below]

La composition du raisin de la variété Muscat d’Alexandrie a été étudiée dans trois terroirs différents au Nord-Est de la Tunisie (RafRaf, Baddar et Kelibia).
Des échantillons de raisins ont été récoltés à maturité industrielle durant les saisons 2001 et 2002 dans les trois régions citées. Les paramètres pomologiques (poids moyen de la grappe et de la baie) et physico-chimiques (acidité totale, pH, densité, degré Brix et indice des polyphénols totaux) ont été immédiatement mesurés. Les composés libres et liés de l’arôme ont été analysés par chromatographie en phase gazeuse (C.P.G.) équipée d’un Détecteur à Flamme d’Ionisation (FID).
Les caractéristiques pomologiques et physico-chimiques n’ont pas subi une modification importante dans les différentes régions étudiées. Cependant, l’effet significatif du terroir se reflète essentiellement sur la composition de la baie en arôme. Bien que la somme des trois monoterpénols (MT; linalol+nérol+géraniol) a toujours été comprise dans le seuil de perception de la note muscatée, une nette différence au niveau de leur distribution a été constatée. Linalol et geraniol sont les composés d’arôme les plus sensibles aux changements des conditions du milieu.
Selon l’année (2001 et 2002) et le terroir, la fraction liée des composés d’arôme est de 4 à 6 fois plus importante que la fraction libre.

The effect of terroir zoning on the pomological, chemical and aromatic composition has been studied on the Muscat d’Alexandrie grapevine variety over two years 2001 and 2002. This variety was cultivated in three terroirs (RafRaf, Baddar and Kelibia) in the North-East of Tunisia.
Muscat d’Alexandrie from each terroir was randomly harvested at commercial maturity, in 2001 and 2002. Pomological parameters (bunch and berry mean weights) and chemical characteristics (total acidity, pH, density, Brix degree and total polyphenol index) have been immediately measured. The aroma free and bound fractions were analyzed using CPG equipped by FID detector.
The results showed that the pomological and chemical parameters were the less affected by the terroir zoning. Nevertheless, zoning affected mainly the aromatic composition of the berry. Although, the global value MT of the free monoterpenols (linalool+nerol+geraniol) was included in the Muscat aroma perception interval, the distribution of the concentration of each changed from region to another. Indeed, linalool and geraniol compounds were the most sensitive to environmental changes and consequently terroirs.
During 2001 and 2002 and according to the terroir, the glycosidically bound fraction has been increased 4 to 6 times.

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DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

Souid I. (1), Zemni H. (1), Ben Salem A. (1) , Fathalli N. (1) , Mliki A. (1), Hammami M. (2), Hellali R. (3) and A. Ghorbel(1)

(1) Laboratoire de Physiologie Moléculaire de la Vigne. Institut National de Recherche Scientifique et Technique. BP 95. Hammam Lif 2050. Tunisia
(2) Laboratoire de Spectrométrie de Masse. Faculté de Médecine de Monastir 5019
(3) Laboratoire d’Arboriculture Fruitière. Institut National Agronomique de Tunis. 43 Av. Charles Nicolle. 1082 Cité Mahrajène. Tunis

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Keywords

Muscat d’Alexandrie, jus de raisin, arôme, terroir, Tunisie

Tags

IVES Conference Series | Terroir 2004

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