Terroir 2004 banner
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.

Download the PDF

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

Contact the author

Keywords

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

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

A new step toward the comprehensive valorisation of grape marc through subcritical water extraction of polysaccharides

Winemaking generates a significant amount of waste. Grape marc, the main solid residue, constitutes 20-25% of the pressed grapes and approximately 8-9 million tons are produced globally each year.

Read More

Distinguishing of red wines from Northwest China by colour-flavour related physico-chemical indexes

Aim: Northwest China occupies an important position in China’s wine regions due to its superior geographical conditions with dry climate and sufficient sunlight. In this work, we aimed to investigate the physico-chemical colour and flavour characteristics of red wine in Northwest China.

Read More

Riesling aroma composition in light of changing global temperatures – delving into the effects of warmer nights on the volatile profile of riesling grapes

Climate is a key parameter when the modulation of berry and subsequent wine composition is considered. Recent decades have already seen an increase in global surface temperatures

Read More

From local classification to regional zoning-the use of a geographic information system (GIS) in Franconia / Germany. Part 1: specific GIS applications in viticulture

En vue d’une production économique de qualités des raisins optimales une connaissance des informations les plus différentes est importante. Les nouvelles technologies, telles qu’un SIG permettent de réunir les informations sur le terrain, la nature du sol, le danger d’érosion, le climat, la végétation, l’hydrographie, l’apparition de nuisible et de maladies, etc. Sur la base de cartes topographiques un SIG permet une vaste analyse, une appréciation des rapports complexes ainsi qu’une représentation cartographique. Sur la base de modélisations en trois dimensions du terrain avec le SIG, les ensembles de données saisies ainsi que leur classification au niveau local peuvent être utilisés dans la production de zonages régionaux.

Read More

Measurement of redox potential as a new analytical winegrowing tool

Excell laboratory has initiated the development of an analytical method based on electrochemistry to evaluate the ability of wines to undergo or resist to oxidative phenomena. Electrochemistry is a powerful tool to probe reactions involving electron transfers and offers possibility of real-time measurements. In that context, the laboratory has implemented electrochemical analysis to assess oxidation state of different wine matrices but also in order to evaluate oxidative or reduced character of leaf and soil. Initially, our laboratory focused on dosage of compounds involved in responses of plant stresses and we were also interested in microbiological activity of soils. These analyses were compared with the measurement of redox potential (Eh) and pH which are two fundamental variables involved in the modulation of plant metabolism. Indeed, the variation of redox states of the plant reflects its biological activity but also its capacity to absorb nutriments. The Eh-pH conditions mainly determine metabolic processes involved in soil and leaf and our goal is to determine if this combined analytical approach will be sufficiently precise to detect biological evolutions (plant health, parasitic attack…).

Read More