Une étude a été menée pendant neuf ans sur deux vignes non-irriguées de Sauvignon blanc commercialisés, plantées à différentes localités (A et B) dans le district de Stellenbosch. Deux parcelles expérimentales, situées sur deux formations géologiques différentes, ont été identifiées au sein de chaque vignoble. A chaque localité une des
Terroir 2004
Flanan-3-ol compositional changes in red grape berries (Vitis vinifera L. cv Cabernet franc) from two terroirs of the Loire Valley (France)
La quantité et la qualité des flavonoïdes sont des éléments importants de la qualité de la baie. En particulier, les tannins contribuent de manière essentielle aux propriétés spécifiques des vins rouges telles que la couleur, l’astringence et l’amertume. Cependant, leur synthèse et leurs propriétés sont encore mal connues. Ainsi, la
The role of mechanization in zone/terroir expression
Vineyard mechanization will be addressed in this review paper primarily as related to pruning and harvesting since these operations typically require a great deal of the total yearly labour demand (Intrieri and Poni, 1998). However, to be able to define how mechanization interacts with “terroir”, a rigorous definition of the latter term is needed.
Analytical and Chemometric Investigation of Phenolic Content of South African Red Wines
Phenolic compounds have been the focus of a lot of research in recent years for their important contribution to sensory characteristics of wine, their beneficial health effects, as well as the possibility they offer of characterising wines. In this contribution, a method is developed that allows the direct injection of wine samples followed by liquid
Applications of Infrared Spectroscopy from laboratory to industry
The grape and wine industries have long sought rapid, reliable and cost-effective methods to screen and monitor all the stages of the winemaking process, which include grape ripening in the vineyard, harvest and grape reception at the weighbridge, the fermentation stage and the bottling of the final product.
Phenolic extraction during fermentation as affected by ripeness level of Syrah/R99 grapes
L’extraction phénolique au cours de la fermentation à partir de vendanges de différents degrees de maturité du cépage Syrah/R99 a été etudiée. Cette travail fait parti d’un projet focalisé sur la qualité du raisin et des vins obtenus au cours du millésime 2002. Les vignes sont situées à Stellenbosch (Afrique du Sud) sur un sol Glenrose
Role of Harvesting Time/Optimal Ripeness in Zone/Terroir Expression
La maturité optimale est définie en fonction du style de vin désiré, qui est fonction du marché. Le sol et le climat ont un effet sur la typicité des vins. Le niveau qualitatif des raisins et des vins, et le potentiel pour obtenir différents styles de vin est déterminé par l’association des caractéristiques naturel du terroir et les technologies mises en
The role of molecular ecophysiology in terroir expression
Terroir is a complex concept which associates soil, climate, grape variety and cultural practices that include the training system and oenological techniques. It is a type of social construction with man at its centre. The typicality of a wine is also a social construction which is the result of an agreement among specialists vis à vis a given quality of the wine whose references are the wine’s origins (e.g. terroir) and taste.
Black foot disease in South African vineyards and grapevine nurseries
Over the last few years a drastic reduction has been noted in the survival rate of vine cuttings in nurseries, as well as in young vineyards in the Western Cape Province of South Africa. The low average take percentages of young vines can be attributed to several factors, including fungal, bacterial and viral diseases, insect and nematode pests,
Contribution of phenolic compounds to the total antioxidant capacity of Pinotage wine
The South African wine industry is taking an interest in the enhancement of red wine total antioxidant capacity (TAC) with retention of sensory quality to satisfy the demands of increasingly discerning consumers. The focus is especially on the unique South African red wine cultivar, Pinotage.
Distribution and associated symptoms of grapevine trunk pathogens in South Africa
In recent studies, several grapevine trunk pathogen complexes have been identified from grapevines in South Africa. These pathogens include Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium sp., Botryosphaeria sp. and Phomopsis sp. Trunk diseases lead to reduced yield, and grape quality as well as a decline
Influence of Partial Rootzone Drying on grape and wine anthocyanin composition
The effect of Partial Rootzone Drying (PRD) on fruit and wine composition has been investigated. At harvest, total anthocyanin and phenolic concentration of Shiraz and Cabernet Sauvignon fruit was either unaltered or increased by PRD relative to control irrigation over two seasons. Where there was an increase in anthocyanin concentration
Partial rootzone drying (PRD): strategic irrigation management as viticultural tool affecting plant physiology and berry quality
Partial rootzone drying (PRD) is an irrigation management technique designed to reduce water use in grapevines without a decline in yield, thereby increasing water use efficiency (WUE). The principle of PRD is to keep part of the root system at a constant drying rate to produce soil derived signals to above-ground plant organs to induce a
Pro-active management of grapevine trunk diseases by means of sanitation in nurseries
Several trunk diseases cause decline and premature dieback of grapevines. In vineyards, these pathogens gain entry into plants through unprotected wounds. Wounds are also frequently infected during the propagation stages. The pathogens survive in infected plants in a latent form and cause disease in older grapevines or in plants that are
Screening of different commercial wine yeast strains: the effect of sugar and copper additions on fermentation and volatile acidity production
The aims of this study were to examine the effect of high sugar concentrations of must and copper residues on different commercial wine yeasts. Copper originating from pesticides has been known to inhibit yeast, but it’s effect on fermentation performance and VA production of different yeast strains had not been investigated in detail.
TCA – A status report on South African cork closures
Cork taint decreases the commercial value of wine as tainted wines are rejected by consumers. Although other compounds in wine and cork can also be responsible for causing a taint, 2,4,6-trichloroanisole (TCA) is regarded as the primary cause of cork taint. As cork taint is often used in marketing campaigns against natural cork closures,
The use of epifluorescence versus plating to monitor the effect of different parameters on microorganisms in wine
The monitoring of the number of micro-orgranisms in wine is crucial for the wine producer. Traditional counting methods include microscopic enumeration and plating on selective media, which measures the culturability of the cells. The use of epifluorescence microscopy is, however, a method, which can measure both culturability and
Sugar loading and phenolic accumulation as affected by ripeness level of Syrah/R99 grapes
Le chargement et l’accumulation des sucres ainsi que la biosynthèse des phénols ont été étudiés sur la Syrah, dans le cadre d’un programme de recherche de paramètres qui permettraient de déterminer une ou plusieurs qualités de raisin en relation avec des styles de vins pour un terroir donné. La relation entre la dynamique d’accumulation des