Part II—Aroma Profile of Twenty White Grapevine Varieties: A Chemotaxonomic Marker Approach

Abstract

The importance of white wines in the northwest of the Iberian Peninsula has led to study on the aromatic profiles of 20 white grapevine varieties along three consecutive vintages. Volatile compounds were evaluated through solid-phase microextraction and gas chromatography-mass spectrometry methodology (SPME-GC-MS). The main aims of this study were as follow: test if their aromatic profile could be used as a potential chemotaxonomic tool to differentiate among grapevine varieties, evaluate if there is any relationship among the aromatic characteristics and the genetic origin of the varieties studied and try to bring out aromatically interesting varieties that could trigger diversified wine production in the study area. Free and bound volatile profiles were tentatively identified in each variety, grouping all identified compounds into thirteen volatile families to allow for a better discussion of the results obtained. Significant differences were found for terpenes among varieties in the free fraction and for acids, aldehydes, terpenes and norisoprenoids in the glicosidically bound fraction. Good differentiation among varieties was achieved by free and glicosidically bound profiles in the principal component analysis (PCA), as well as some clustering of varieties belonging to the same genetic reconstructed populations (RPP). Varietal aromatic profiling could be expected to be a good chemotaxonomic tool.