EFFECTS OF INDUCED SUNBURN DAMAGES ON WHITE WINE PROPERTIES

The color as well as the “clarity” of red wines are ones of the qualities required by the consumers. Red wines must have colloidal stability from its bottling to its consumption. The supplementation of red wines with additives, and especially Acacia senegal gum, contributes to its organoleptic properties such as the colloidal stabilization of the coloring matter. In a global perspective of limitation of additives in the field of enology, one of the objectives is notably (i) to reduce the use of additives in wines, by their number and/or their quantity, and (ii) to favor the use of natural additives while preserving the organoleptic and sensory qualities of wines.

Sulphur dioxide has been used for many years for its antimicrobial, antioxidant and antioxydasic properties in winemaking but nowadays, it is a source of controversy. Indeed, consumers are more attentive to the naturalness of their foods and beverages and the legislation is changing to reduce the total SO₂ levels allowed in wines. To limit and replace the doses of sulphur dioxide applied, winemakers can now use bioprotection consisting in live yeast addition as alternative,seems to be promising. This process, lightly used in from the food industry, allows to colonize the environment and limit the development or even eliminate undesirable microorganisms without altering the sensory properties of the product.

The quality of wines has often been associated with their geographical area of production. The aim of this work was to characterize Protected Designation of Origin (PDO) Xinomavro red wines from different geographical areas of Amyndeon and Naoussa in Northern Greece, elaborated with variables that contribute to their differentiation, such as soil characteristics, altitude, monthly average temperature and rainfall.
Xinomavro fruit parcels from different vineyards within the two PDO zones (5 PDO Naoussa and 6 PDO Amyndeon) were vinified following a standard winemaking process. A total of 25 aroma compounds were quantified using gas chromatography-mass spectrometry (GC-MS) with simultaneous full scan and selected ion monitoring for data recording, and odor activity values (OAVs) were determined.

Phenolic compounds play a central role in sensory characteristics of wine, such as colour, mouthfeel, flavour and determine its shelf life. Furthermore, the major non-enzymatic wine oxidation process is due to the catalytic oxidation of phenols in quinones. Due their importance, during the years have been developed different analytical methods to monitor the concentration of phenols in wine, such as Folin-Ciocalteu method, spectrophotometric techniques and HPLC. These methods can also be used to follow some oxidation-related chemical transformations.

Grape quality potential for wine production is strongly influenced by environmental parameters such as climate and agronomic factors such as rootstock. Several studies underline the effect of rootstock on vegetative growth of the scions [1] and on berry composition [2, 3] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Little is known about the effect of rootstock genetic variability on the aromatic composition in wines; thus further investigations are needed.