Amino Acid Profiles to Differentiate White Wines from Three Autochtonous Galician Varieties.

José Manuel Mirás-Avalos,Emiliano Trigo-Córdoba,Yolanda Bouzas-Cid,Elena Falqué,Ignacio Orriols

doi:10.3390/foods9020114

Abstract

Amino acids play a relevant role in wine quality and can allow for classifying wines according to the variety. In this work, the amino acid contents of Albariño, Godello, and Treixadura wines, three autochthonous varieties from Galicia (NW Spain), were determined. During three consecutive vintages, these varieties were grown on the same vineyard and were harvested at optimum maturity, and the wines were elaborated following the same enological protocol. The identification and quantification of the primary amino acids were carried out by high-performance liquid chromatography with photodiode array detection, after a derivatization. Amino acid contents in these white varieties were within the range of values reported for other European wines, but Treixadura wines showed the highest concentrations, while wines from the Albariño variety showed the lowest contents. Apart from proline, whose concentrations were caused by yeast release, the most abundant amino acids were aspartic acid, glutamic acid, lysine, arginine, asparagine, alanine, and histidine. Principal component analysis separated wines by variety according to their amino acid contents.

Highlights

The amino acids present in grapes are consumed by yeasts during alcoholic fermentation and might yield some higher alcohols, aldehydes, esters, and other volatile compounds [1], influencing the final wine aroma [2]
The most negative values of Ψstem were observed on dates close to harvest, the vines only suffered from a slight to moderate water stress over the three studied years
In 2013, Albariño suffered from less water stress intensity than Godello and Treixadura, which was the variety most affected by this abiotic stress (Figure 2)

Summary

Introduction

The amino acids present in grapes are consumed by yeasts during alcoholic fermentation and might yield some higher alcohols, aldehydes, esters, and other volatile compounds [1], influencing the final wine aroma [2]. Amino acid nature and concentrations in grapes depend on a wide range of factors, such as fertilization, climatic conditions, and grape variety [1], but the amino acid profiles were successfully employed by several researchers for differentiating and classifying grapes or wines from different varieties, management conditions and growing regions [5,6]. Soufleros et al [7] were able to classify French wines from several terroirs (Bordeaux, Bourgogne, Alsace, Champagne) according to their origin, type, and aging through the analysis of 21 amino acids, biogenic amines, and volatile substances. Martínez-Pinilla et al [9] differentiated red wines from Tempranillo, Monastel and Maturana Tinta de Navarrete according to grape variety, malolactic fermentation and vintage; concluding that wines from

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