Water and nutritional savings shape non-structural carbohydrates in grapevine (Vitis vinifera L.) cuttings

The use of oenological additives is becoming a common practice due to the technological and sensory properties they provide to the wines. However, the number of studies focused on the impact that these additives might induce on wine flavor perception during wine tasting is still quite scarce. The aim of this work was to evaluate the effect of three different types of common oenological additives: two oenotannins (ellagitannin and gallotannin) and a commercial preparation of yeast mannoproteins on the long-lasting flavor perception (aroma and astringency).

Climate changes have important consequences in viticulture, heat waves accompanied by periods of drought are encountered more and more frequently. This study aims to evaluate the single and combined effect of water deficit and high temperatures on the thiol precursors biosynthesis in Sauvignon blanc grapes. For this purpose, a protocol has been developed for the cultivation of berries on a solid substrate. The berries, collected at three different times starting from veraison and grown in vitro, were subjected to 4 different treatments: control (C), water stress (WS), heat stress (HS), combined water and heat stress (WSHS). Water stress was simulated by adding abscisic acid to the culture medium, while different temperatures, respectively 25°C and 35°C, were managed with two illuminated climatic chambers.

The actual climate changes, together with the strong regulation of the European Union and Spanish government, in search of sustainable viticulture, have forced the recovery of minority varieties, expanding the range of grape varieties, as well as the possible development of wines with unique profiles. In the Ribeira Sacra DO (Spain), a comparative study of the agronomic and qualitative behavior of the ‘Branco lexítimo’ variety has been carried out, compared to the majority white variety in the DO: ‘Godello’, located in the same study plot, with identic soil and climatic conditions. The study contemplated the analysis of phenology and leaf water potential, as well as the productive results and the analysis of the must quality, during four seasons: 2018 – 2021.

The quantity and distribution of polyphenols in musts play a fundamental role in the white winemaking. This is because these substances are exposed to oxidation reactions, which are catalysed by the polyphenol oxidase (PPO), leading to a decrease in the quality of the wines produced. PPO is inactivated by SO2, but currently, due to the restrictions of the legislation, other methodologies are being investigated. Ultra-High Pressure Homogenization (UHPH) is a non-thermal physic technology that exerts an ultrahigh pressure pumping (>200 MPa) of a fluid through a valve in a continuous system.

Volatile organic compounds (VOCs) constitute a diverse group of secondary metabolites key for the communication of plants with other organisms and for their adaptation to environmental and biotic stresses. The emission of these compounds through leaves is also affected by the interaction of plants with symbiotic microorganisms, arbuscular mycorrhizal fungi (AMF) among them [1]. Our objective was to know the concentration and profile of VOCs emitted by the leaves of two grapevine varieties (Tempranillo, T, and Cabernet Sauvignon, CS, grafted onto R110 rootstocks), inoculated or not with a consortium of five AMF (Rhizophagus irregularis, Funneliformis mosseae, Septoglomus deserticola, Claroideoglomus claroideum and C. etunicatum).