Arsenic in soil, leaves, grapes and wines

Una de las biotecnologías más potentes para disminuir el pH en vinos de zonas cálidas y en variedades de pH elevado es el uso de la levadura no-saccharomyces lachancea thermotolerans. Esta especie es capaz de formar ácido láctico a partir de azúcares, reduciendo al mismo tiempo ligeramente el grado alcohólico. Por lo tanto, mejora dos de los principales problemas de los vinos de regiones afectadas por el calentamiento global. El ácido láctico es un ácido orgánico con una buena integración sensorial en el sabor del vino, y también química y biológicamente estable durante el envejecimiento del vino.

The French “Coteaux du Layon” Appellation of Origin has built its Jarne on the production of sweet white wines. A network of experimental plots, based on the “terroir” concept, was established in 1990; it allows for the follow-up of the overripening behaviour of the grapes in relation with the agroviticultural parameters.

In 2008 the anthocyanin, flavonol and hydroxycinnamate (HCT) contents of the skins of five coloured berry cultivars (‘Escursac’, ‘Esperó de Gall’, ‘Galmeter’, ‘Valent negre’ and ‘Vinater negre’), of two white cultivars (‘Argamussa’ and ‘Prensal blanc’) and of one weakly rose cultivar (‘Giró ros’), native from Balearic Islands, were characterized.

Un travail sur les A.O.C. du piémont pyrénéen occidental permet de construire une hiérarchie de paramètres climatiques, géo-pédologiques, morphologiques, de saisir leurs niveaux d’interaction et d’élaborer une méthodologie pour proposer un zonage

In wine grape production, canopy management practices are applied to control the source-sink balance and improve the cluster microclimate to enhance berry composition. The aim of this study was to identify the optimal ranges of berry solar radiation exposure (exposure) for upregulation of flavonoid biosynthesis and thresholds for their degradation, to evaluate how canopy management practices such as leaf removal, shoot thinning, and a combination of both affect the grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) yield components, berry composition, and flavonoid profile under context of climate change. First experiment assessed changes in the grape flavonoid content driven by four degrees of exposure. In the second experiment, individual grape berries subjected to different exposures were collected from two cultivars (Cabernet Sauvignon and Petit Verdot). The third experiment consisted of an experiment with three canopy management treatments (i) LR (removal of 5 to 6 basal leaves), (ii) ST (thinned to 24 shoots per vine), and (iii) LRST (a combination of LR and ST) and an untreated control (UNT). Berry composition, flavonoid content and profiles, and 3-isobutyl 2-methoxypyrazine were monitored during berry ripening. Although increasing canopy porosity through canopy management practices can be helpful for other purposes, this may not be the case of flavonoid compounds when a certain proportion of kaempferol was achieved. Our results revealed different sensitivities to degradation within the flavonoid groups, flavonols being the only monitored group that was upregulated by solar radiation. Within different canopy management practices, the main effects were due to the ST. Under environmental conditions given in this trial, ST and LRST hastened fruit maturity; however, a clear improvement of the flavonoid compounds (i.e., greater anthocyanin) was not observed at harvest. Methoxypyrazine berry content decreased with canopy management practices studied. Although some berry traits were improved (i.e. 2.5° Brix increase in berry total soluble solids) due to canopy management practices (ST), this resulted in a four-fold increase in labor operations cost, two-fold decrease in yield with a 10-fold increase in anthocyanin production cost per hectare that should be assessed together as the climate continues to get hot.