87Sr/86Sr isotope ratios in soils, vine leaves, grapes and wines of the Italian volcanic districts authenticate their respective terroirs

Interest in the origin and traceability of agri-food products has led to an increasing number of publications using strontium isotope ratios as a geographic tracer. We used 87Sr/86Sr isotope systematics to authenticate the provenance of wine from different volcanic districts of Italy. Samples of soil, grapes, leaves and bottled wines from 6 different wineries were analysed. A detailed study of the different soil horizons from the Somma-Vesuvio area demonstrates the relationship between the 87Sr/86Sr of the soils and the different parts of the grapevine (root, steam, grape, grape pulp, grape seed, grape skin), and the soil characteristics (soil type, granulometry, root density) that control the 87Sr/86Sr of the end-products. Results showed that the geological characteristics of volcanic terranes of Italy, and in particular the northwest to southeast 87Sr/86Sr gradient, are inherited by the wines of each region, such that the wines can be discriminated and authenticated by their isotope ratios