Grape and wine amino acid composition from Carignan noir grapevines growing under rainfed conditions in the Maule Valley, Chile: Effects of location and rootstock

Abstract Nitrogen compounds play a key role on grape and wine quality. Their composition in grapes depends mainly on variety, viticultural management, and terroir, and affects fermentation kinetics and the volatile compound formation. The aim of this work was to study grape and wine amino acid composition of ungrafted or grafted onto cv. Pais Carignan grapevines growing under rainfed conditions in ten sites of the Maule Valley (Chile). The results showed that proline was the most abundant amino acid in grapes and wines. In general, Carignan noir grapevines grafted over Pais showed lower grape amino acid content respect to ungrafted vines. Cool night index (CI) was inversely correlated to several amino acids, showing that their plant synthesis or accumulation increased with lower minimum temperatures during the last month before harvest. Truquilemu (Tru) and Cienaga de Name (Cdn) sites showed the highest concentration for several amino acids and total amino acid content in grapes, which led to a faster alcoholic fermentation.