Free and Glycosylated Aroma Profiles of Vitis vinifera cv. Tamarugal Wines from the Hyperarid Atacama Desert Across Vintages and Vinification Practices

Viticulture in hyper-arid environments represents an emerging frontier in non-traditional winegrowing regions, where extreme climatic conditions may be associated with distinctive grape and wine chemical composition. In this study, four wines produced from Vitis vinifera cv. Tamarugal cultivated in the Atacama Desert (Chile) were characterized based on their volatile organic compound composition, with particular emphasis on free and glycosylated aroma-related volatile fractions. Wines from four production years (2019–2022), obtained under different vinification approaches, were analyzed using solid-phase extraction followed by GC–MS. The free volatile fraction was dominated by lipid-derived compounds, including fatty acid-derived alcohols, acids, and esters, whereas the glycosylated fraction was enriched in C13-norisoprenoids and benzenoid/phenylpropanoid-derived precursors, highlighting a substantial pool of bound volatile compounds. Multivariate analyses, including principal component analysis (PCA) and supervised partial least squares–discriminant analysis (PLS-DA), were applied to explore patterns in volatile composition and support visualization of variables associated with sample differentiation. The observed compositional differences were associated with the combined influence of vintage and vinification conditions, which could not be experimentally disentangled in the present study. This study provides the first characterization of free and glycosylated volatile profiles in wines produced in the Atacama Desert and contributes to the understanding of wines from non-traditional hyper-arid viticultural conditions.