Productivity, quality, and thermal needs of the Piedirosso vine: four years of observations

Wine is a luxury product and a global beverage steeped in history and mystery. Over time, various regions have become renowned for the quality of wines they produce, which adds considerable value to the regions and the brands. On the whole, the international wine market is worth many hundreds of billions of dollars, which attracts unscrupulous operators intent on defrauding wine consumers.

Grape volatile compounds are mainly responsible for wine aroma, so it is important to know the va-rietal aromatic composition throughout ripening process. Currently, there are no tools that allow mea-suring the aromatic composition of grapes, in intact berries and periodically, throughout ripening, in the vineyard or in the winery. For this reason, this work evaluated the use of near infrared spectroscopy (NIR) to estimate the aromatic composition and total soluble solids (TSS) of Tempranillo Blanco berries during ripening. For this purpose, NIR spectra (1100-2100 nm) were acquired from 240 samples of in-tact berries, collected at different dates, from veraison to overripening.

Depuis 1973, une commission statutaire administre la législation qui régit le zonage vitivinicole en Afrique du Sud. La province «Le Cap de l’ouest» cerne toutes les zones viticoles sauf quatre unités. Pour la plupart, le Cap de l’ouest a un climat méditerranéen. Les zones viticoles – qui produisent les «vins d’origine» – sont des régions, des districts, des quartiers et des domaines. Les régions sont vastes, séparées par la topographie, par ex. des chaînes de montagnes et des fleuves. Généralement, chaque région représente une zone climatique. Le climat de chaque district est plus homogène. Les quartiers sont exactement délimités par le climat, la topographie et la géologie. Les domaines sont les plus petits. Chaque domaine doit avoir un seul propriétaire.

Quercetin-3-glucoside, a grape flavonol defence metabolite, is extracted during winemaking and may undergo subsequent degradation in wines. Hydrolysation reactions lead to the formation of the aglycone quercetin, which presents limited solubility in the wine matrix and can induce visible precipitations.

The composition of grape berry cell walls was studied on two grape varieties, two years and two maturation levels at the same time as the extraction of anthocyanins and tannins. The chemical composition of skins, seeds, and pulps, focused on polyphenols and polysaccharides, was compared to the chemical composition in polyphenols after extraction from the skins in model solutions or after wine making of the berries. Polyphenols were mainly characterized by UPLC-MS and HPLC-SEC. Polysaccharides were characterized by analysis of the neutral sugar compositions, and also by the CoMPP (comprehensive micropolymer profiling) analysis, a new method which targets the functional groups of cell wall polysaccharides.