Terroir impact on polyphenols

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  • Publié le : 28 juin 2010
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Table of contents
Introduction 1
I) Polyphenols 2
A) Stage of grapes formation 2
B) Role of polyphenol 2
C) Different class of polyphenols 2
D) Phenolic biosynthesis 3
E) Hormones acting in relation with polyphenol 4
II) Climate 5
A) Sunlight 5
B) Sunlight and temperature 5
C) Temperature 6
1) Effect of temperature on stage of berry 6
2) Day/nighttemperature effect 6
3) Physiological impact of the temperature 7
D) Cultural practices 7
III) Interaction between soil and polyphenol 9
A) Water availability 9
1) Direct response 9
2) Indirect response 10
B) Nitrogen and potassium interaction with polyphenol content 11
1) Impact on polyphenol. 11
2) Physiologic effect 11
C) Cultural practices 12
IV) Wine making influence 13A) Interest of the maceration 13
B) Maceration type 13
1) Maceration 13
2) Short maceration 14
3) Extended maceration 14
4) Cold maceration 14
5) “Saignée” 15
6) Impact of different other methods 15
C) Impact of the SO2 15
D) Micro-oxygenation 16
E) Malolactic fermentation and ageing 16


Terroir is a complexconcept that requires a multidisciplinary approach.
Some authors have been able to develop relatively simple theories on the definition of terroir. In some cases, it is reduced to the only relationship between soil-climate, vineyards and wine. In contrast, a number of geographers argue the theory that the origin of terroir is purely human and social. Nowadays all agree that terroir can be defined as aunique and delineated geographical area in which a human community built a collective knowledge based on a system of interaction between biological and physical environment, and a set of human factors. The terroir also involves specific landscape features and values of the territory (Fanet, 2007).
Terroir is thought of as a product with a character linked to its place of production, andsometimes to the methods being developed from local traditions. This character is often qualitative and is driven by producers who normally make every effort to get it.

For several years, meteorologists observe global weather changes, particularly at a regional level with an acceleration in the northern hemisphere, towards global warming (Arnell et al., 2003). This climate change is often associatedwith strong summer drought conditions, causing significant water stress on the vine (A. Carbonneau J-L. Escudier, 2004).

When it comes to wine, the character should be reflected in the uniqueness of its organoleptic characteristics. During the past two decades, classic indices of maturity have been abandoned, and new parameters, such as ‘‘phenolic maturity’’ or the content of different phenoliccompounds in the grape, considered. This change of thinking is due to the belief that only grapes with high and balanced levels of phenols could produce quality red wines, suitable for ageing (Gonzalez-Sanjose et al., 1991).

The quality of phenolic compounds in the berries is linked to the concept of terroir, with concentrations being subject to the influence of environmental conditions(Ribereau-Gayon et al., 1976): water supply (Roby et al., 2004), mineral nutrition (Hilbert et al., 2003), temperature and sunlight (Spayde et al, 2002).

Terroir studies enable producer to a better understanding of their vineyards and to improve their product. This seminar will attempt to explain in more detail the impact of different parts of the terroir on the polyphenol synthesis and some timesmore precisely on the anthocyanin synthesis. First, an overview of polyphenols will be done following by the impact of the climate and then the impact of the soil component on the synthesis pathway. This will be linked with the principal practices permitting to improve this synthesis from the vineyard to the cellar.

I) Polyphenols

A) Stage of grapes formation

During the fruit...