Free amino acid composition of must from 7 Vitis vinifera L. cv. in Latium (Italy)

Free amino acid concentrations in must of 7 Vitis vinifera cultivars (Cabernet Franc, Syrah, Merlot, Montepulciano, Sangiovese, Cesanese d’Affile, Carmenere) grown in the Latium region (Italy) were monitored from 2003 to 2005. The cultivars were located in a homogeneous soil and climatic zone and with the same training system (Cordon Spur). The influence of climate was assessed with year-to-year variations of maximum and minimum temperatures and rainfall. The amino acids were compared individually to show year-to-year variations. The concentrations of individual amino acids differed considerable between years, whereas the amino acids profile did not differ significantly from one year to another in all 7 cultivars studied. Arginine, proline, varied between years, while proline: arginine ratio did not change. Arginine, proline, proline: arginine ratio, total free α–amino acid and total free α–amino N concentration were not correlated with soluble solids concentration at harvest. The sum total of amino acids in musts differed significantly from one variety to another and was used as an index to differentiate between varieties from the same area.