Characterization of phenolic composition of Vitis vinifera L. ‘Tempranillo’ and ‘Graciano’ subjected to deficit irrigation during berry development

Abstract

The response of phenolic composition of skins from Vitis vinifera L. ‘Tempranillo’ and ‘Graciano’ grapes to water-deficit irrigation during berry growth and ripening was evaluated. The study was carried out using container-grown grapevines grown under controlled conditions in a greenhouse. Two irrigation treatments were imposed: control (well-watered) and sustained deficit irrigation (SDI). Twenty-eight phenolic compounds, including anthocyanins, flavonols and monomeric flavan-3-ols (catechins) as well as phenolic acids derivatives have been identified in the extracts prepared from the berry skins at physiological maturity. For both varieties, water deficit reduced leaf area and leaf area to crop mass ratio, and decreased berry size. However, there were no changes in juice total soluble solids, pH or total polyphenolic content. Water deficit resulted in decreased must titratable acidity in ‘Graciano’ berries. In ‘Tempranillo’, water limitation reduced total anthocyanins and flavonols, and increased hydroxycinnamic acids. In ‘Graciano’, water deficit resulted in increased flavonols and reduced catechins. Altogether, we concluded that under water-deficit irrigation, ‘Graciano’ grapes presented a differential composition of phenolic compounds that could result in improved fruit quality.