ASSESSMENT OF ‘DOLCETTO’ GRAPES AND WINES FROM DIFFERENT AREAS OF OVADA DOCG

Abstract

Dolcetto (Vitis vinifera L.) is one of the traditionally cultivated varieties in Piedmont (north-east Italy). Dolcetto wines have long been associated with local consumption and they are little known internationally. In particular, the Ovada area (south-east Piedmont), even if it represents a small share of the regional PDO Dolcetto production, is one of the oldest and vocated territory, giving wine also suitable for aging. In this study, the basic composition and phenolic content of Dolcetto grapes for Ovada DOCG wines have been investigated in three different vintages (2020-2022), as well as the main aspects of the derived commercial and experimental wines (basic parameters, phenolics, volatile compounds, sensory properties).

Grapes from fifteen vineyards, belonging to three Ovada DOCG areas, were harvested at the same grape soluble solids content (about 13.0-13.5% v/v potential alcohol) and were evaluated in terms of basic traits, phenolic ripeness, and skins and seeds phenolic composition. The commercial wines produced from these vineyards were analyzed for 2020 and 2021 vintages. Among them, representative vineyards were also selected for experimental standardized winemaking to establish correlations between grapes and wines results.

The results showed different acidic content at harvest, with higher values for area 3 that resulted also in lower sugar content, and differences among the vintages studied according to the weather conditions (2020 was wetter than 2021 and 2022). The phenolic ripeness parameters changed moderately among the three areas, even though the cell maturity index (EA%) and the seed maturity index (Mp%) reported no significant differences, with a higher vintage effect. The berry skins phenolic composition differed among areas, being the lower values of total polyphenols, total flavonoids, and total anthocyanins observed in area 1. Significant differences for polyphenols were found depending also on the vintage. Moreover, the seasonal conditions affected the berry weight, increasing the seeds polyphenols ratio on the total content in the drier years (2021-2022) although with different extent depending on the area. The results on experimental wines could be useful to assess if they correspond to those predicted from grape analysis, helping winemakers in improving vinification protocols according to the desired wine style. Acknowledgements. We thank the Consorzio di Tutela dell’Ovada DOCG and its associates for supporting this study.