Soil effect on proanthocyanidins composition of red and white wines obtained from Nero d'Avola and Grillo Vitis vinifera L. Cultivars.

In this study, the effects of the main soil chemical-physical parameters (i.e. texture, pH, total carbonates, cation exchange capacity, electric conductivity, organic matter and mineral endowment) on proanthocyanidin composition of Nero d'Avola red wines and Grillo white wines were investigated. Monomer proanthocyanidins (i.e. (+)-catechin and (-)-epicatechin) and oligomer proanthocyanidins (i.e. B1, B2, B3 and B4 dimers and C1 trimer), as well as proanthocyanidins subunit composition, percentage of galloylation, percentage of prodelphinidins and mean degree of polymerization, were studied for each wine. Results highlighted that the proanthocyanidins composition of both red and white wines is greatly affected by soil. In particular, the proanthocyanidins composition of Nero d'Avola red wines appeared to be affected by the soil physical-chemical parameters related to nutrients dynamics (CEC, EC, pH, organic matter, mineral endowment), whereas the proanthocyanidins composition of Grillo white wines was mainly influenced by the soil texture, that modulates soil water dynamics.