Application of high-resolution climate measurement and modelling to the adaptation of New Zealand vineyard regions to climate variability

The use of oenological tannins is authorized for many years by the OIV and advised for color stabilization. For this reason, winemakers look for a better understanding of tannins/anthocyanins interactions to produce deeply colored wines with great color stability during aging.

Solo attraverso un adeguato intervento di estirpazione e reimpianto dei vigneti è possibile preservare, adeguare e valorizzare il patrimonio viticolo e le produzioni che da esso derivano.
Il reimpianto dei vigneti è pertanto da intendersi come una normale pratica agricola, alla pari della rimonta di stalla in campo zootecnico, ma può assumere toni problematici quando, come si verifica adesso in Toscana per una serie di circostanze legate alla profonda trasfor­mazione della viticoltura avvenuta negli ultimi 30 anni, troppi impianti giungono contem­poraneamente a fine ciclo produttivo e devono essere rinnovati.

The vocabulary used to describe wine aroma is commonly organized according to color, raising the question of whether they reflect the reality of olfactory perception. Previous studies have assumed this convention of color-aroma matching, and have investigated color’s influence on the perception of aroma only in dyed white wine or in red wine from particular places of origin. Here 48 white and red varietal wines from around the world were evaluated in black glasses then in clear glasses by a panel of wine experts, who gave intensity ratings for aroma attributes commonly used by wine professionals. In black glasses, aromas conventionally associated with white wine were perceived in the red wines, and vice versa.

La véraison, stade intermédiaire du développement de la baie de raisin, correspond au début de la maturation. Aux modifications de coloration de la pellicule sont associées une perte de fermeté, une diminution de l’acidité et une augmentation des teneurs en sucres et pigments ainsi que du volume de la baie. Le stade de véraison des cépages blancs reste difficile à apprécier visuellement. Son évaluation par palpation est subjective et donc sujette à caution.

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.