Relationship between amino acid profile of grapes affected by early leaf removal and Albariño wine aromatic composition

Abstract

The arnino acids present in grapes play an important role in enology because affect to wine quality. Each grape cultivar has an arnino acid profile and this profile can be affected by variations due to the geographic area, the vintage or the maturity leve!. Amino acids are consumed by yeasts as a source of nitrogen during alcoholic fermentation and are precursors of aroma compounds (alcohols, esters and acetates rnainly). The aim of the present work was to know the influence of the early leaf removal on arnino acid composition of grape and the relationship with volatile composition ofwine. Fourteen arnino acids from five early leaf removal treatments in Albariño grape (control and defoliation in two phenological phases plant, flowering and fruit and two different intensities, 4 and 8 basal leaves) were tested by HPLC (Biochrom autoanalyzer). The musts were fermented in the same conditions and twenty fermentative volatile compounds in Albariño wines were identified and quantified by GC-MS. ANOV A results showed that significant differences among ami no acid composition of musts not were found; therefore varietal arnino acid profile was not affected by treatment of leaf removal. However eight volatile compounds showed significant differences among wines from early leaf removal treatments. The PLSR showed relationship among eleven grape arninoacids and eight wine volatile compounds, mainly esters and acetates.