Effects of regulated deficit irrigation (RDI) on grape composition in Monastrell grapevines under semiarid conditions

Tannin composition is an important attribute in red wine quality, and it is therefore critical to understand the factors influencing tannin extraction during alcoholic fermentation. Tannins contribute to the mouthfeel of wines, but they also form pigmented polymers...

Context and purpose of the study. The vine nursery sector is undergoing a transformation to meet growing environmental and sanitary demands.

Acidity adjustments are key to microbial control, sensory quality and wine longevity. Acidification with cation exchange resins -in acid cycle- offers the possibility to reduce the pH by exchanging wine cations, such as potassium (K+), for hydrogen ions (H+). During the exchange process, the removal of potassium and calcium ions contributes to limiting the formation of tartrate salts, thus offering an alternative solution to conventional methods for tartrate stability. Moreover, the reduction of wine pH and the removal of metals catalyzers (e.g. iron) could positively impact the wine’s oxidative stability. Therefore, the aims of this work were (a) to optimize the ion exchange process by testing different volumes and concentrations of sulfuric acid (H2SO4) during the acid cycle, (b) evaluate the effects of the ion exchange process on the formation of tartrate salts, and (c) analyze the oxidative stability of the treated wines.

Diverse ripening disorders affect grapevine resulting in high economic losses worldwide. The common obvious symptom is shriveling berries, however the shriveling pattern and the consequences for berry quality traits are distinct in each disorder. Among them, the disorder berry shrivel is characterized by a reduced sugar accumulation short after the onset of berry ripening leaving the clusters unsuitable for wine processing. Although our knowledge on BS increased recently, potential internal or external triggers contributing to the induction of BS are yet to be explored.

In the present study the connection between the positional candidate gene VvDXS and muscat flavor was evaluated by investigating the expression profiles in the berries from a Muscat-type cultivar and a neutral cultivar and its nucleotide diversity of full ORF on grapevine accessions.