Amino acid content of Agiorgitiko ( Vitis vinifera L. cv.) grape cultivar grown in representative regions of Nemea

The concentration of yeast assimilable nitrogen (YAN) content in grape musts of selected representative vineyards of Nemea wine region was determined for 3 consecutive years. It was also of interest to investigate the effect of climatic conditions and vineyard altitude on YAN concentration. Amino acids were analyzed by High-Pressure Liquid Chromatography (HPLC), and 18 were identified and quantified. The majority of grape samples presented a deficiency in yeast assimilable nitrogen required for successful wine fermentation according to the literature. None of the samples had ammonia nitrogen content more than 2 mg N/L. The predominant amino acids quantified were arginine followed by proline, glutamine, and glutamic acid. Based on the ratio of arginine and proline, Agiorgitiko is probably weak or net arginine accumulator. A general tendency of increasing amino acid content with temperature was reported, while the opposite was evident for rainfall. Climatic conditions and cultivar are more likely the most important parameters affecting amino acid concentration in grapes.