Diversity among Traditional Minority Red Grape Varieties According to Their Aromatic Profile

Abstract

Free and glycosidically-bound aromatic characterization of 21 minority red grapevine varieties was carried out, along three consecutive vintages, using solid phase microextraction followed by gas chromatography-mass spectrometry methodology (SPME-GC-MS). The two main study aims were to evaluate the possibility of aromatically differentiated varieties based on their origin and to test the aromatic profile for being used as a chemotaxonomic tool. Based on the results obtained in this research, it would be also interesting to verify in future studies if this varietal diversity could translate into a diversification of quality products in the current globalized wine market. A volatile profile was established grouping aroma compounds into thirteen families: acids, alcohols, esters, C6 compounds, thiols, ketones, aldehydes, phenols, terpenes, C13-norisoprenoids, lactones, polycyclic aromatic hydrocarbons (PAHs), and sesquiterpenes. Significant differences were found among varieties for esters, phenols, terpenes, and total compounds in the free fraction and for alcohols, acids, C6 compounds, C13-norisoprenoids, terpenes, sesquiterpenes, and total compounds in the glycosidically-bound fraction. Subtle differentiation between different groups of varieties with common genetic origin was achieved by free aromatic profile (PCA) component analysis. Nevertheless, more in-depth studies are considered necessary to confirm the usefulness of the aromatic profile as a chemotaxonomic tool.