Effects of irrigation over three years on the amino acid composition of Albariño (Vitis vinifera L) musts and wines in two different terroirs

Amino acids and ammonium are the main nitrogen sources for Saccharomyces cerevisiae and are necessary for the correct development of the alcoholic fermentation. These compounds are aroma precursors and, therefore, variations in their concentrations may influence wine quality. Irrigation might alter amino acid concentrations in grapes. In this context, the effect of irrigation on the amino acid profiles of the white grapevine (Vitis vinifera L.) variety Albariño was studied over three consecutive vintages (2012, 2013 and 2014). The experiment was carried out in two vineyards included in two different Appellation of Origin (AOC) in NW Spain. Arginine was the most abundant amino acid found in Albariño musts. Irrigation did not alter the total concentration of amino acids in the must, but it did on certain amino acids, especially methionine. Wines from the different treatments showed similar concentrations of amino acids, except in 2013. Vintage had a strong effect on the amino acid content in musts, likely related to weather conditions.