Uncovering terroir identity through elemental fingerprinting at an organic Douro Valley vineyard

The concept of terroir links wine production and quality to the specific location where grapevines are cultivated. Terroir wines reflect distinct soil characteristics, composition, topography, climate, and biodiversity. Grapevine development and ripening are influenced by soil temperature, water availability, and mineral supply. Elemental soil properties and anthropogenic factors affecting bioavailability are mirrored in agricultural products. Consequently, the accumulation of chemical elements in plants creates a unique fingerprint that characterizes geographical origin and supports product traceability. Elemental composition and multivariate statistical analyses have proven highly effective in identifying and classifying specific agricultural products according to their geographical provenance. In this study, we analyzed the elemental composition of the soil and leaves from five different terroirs sharing the same dominant geological formation using Total Reflection X-ray Fluorescence (TXRF) spectroscopy. The study demonstrated that soil and leaf elemental profiles serves as terroir signatures, with high accuracy achieved through unconstrained (92 % for both) and constrained (96 % and 100 %, respectively) chemometric analysis. Our findings underscore the specificity of each terroir , distinctly marked by their unique elemental signatures, which can be employed for authenticity purposes, allowing high-confidence confirmation of terroir identity, combating wine fraud, and promoting the valuation of the terroir 's identity and its products. • TXRF spectroscopy was used as a chemometric tool. • Elemental composition of soil and grapevine leaves is a terroir signature. • This approach enabled terroir traceability in the same geological formation.