Volatile fingerprint and physico-mechanical properties of ‘Muscat blanc’ grapes grown in mountain area: a first evidence of the influence of water regimes.

The volatile composition of aromatic grape varieties at harvest is a very important criterion in the choice of vinification technique to yield the optimal quality of the final product. The berry mechanical characteristics are important for assessing resistance to fungal attacks and for the estimation of shattering. In this study the effect of irrigation on the volatile fingerprint and the mechanical properties of the Muscat blanc (Vitis vinifera L.) grapes grown in mountain north-west region of Italy was investigated. Three water regimes were compared: standard irrigation, moderate irrigation and drought. In the meteorological conditions of the considered season, a significant increase in the amounts of the most representative free volatile components of the Muscat blanc variety (linalool and geraniol markers), was observed in standard irrigation treatment. Significantly higher amounts of four C13-norisoprenoid bound compounds were observed in the drought treatment with respect to the standard treatment. Furthermore, no influence of irrigation treatment on berry skin hardness and thickness parameters was noted. Therefore, in the considered alpine environment, on aromatic Muscat blanc variety, the optimum irrigation treatment is an important choose to improve the quality of the grapes.