A comparative 87Sr/86Sr study in Red and White wines to validate its\ud use as geochemical tracer for the geographical origin of wine

摘要

Recently high precision 87Sr/86Sr analyses have shown that Red wines keep the isotopic values of the vineyard\udsubstratum. Indeed, neither biological nor winemaking and aging processes are able to change the 87Sr/86Sr values\udthrough the oenological food chain from grapes to Red wine. In addition, 87Sr/86Sr of Red wines and those of rocks\udfrom the geological substratum of their vineyards correlate directly. The same holds not true for White wines,\udapparently. To investigate this discrepancy, 87Sr/86Sr has been determined for the entire production chain, from\udterroir to final product, of Red and White wines from the same vineyard. Sr-isotope data have been also determined\udfor the young pyroclastic rocks of the geological substratum, and the soil of the vineyard to disambiguate the\udoriginal contribution to the 87Sr/86Sr values of wines. Further Sr-isotope data have been determined on additives used\udfor fining the White wine. The analytical results do not show significant differences between oenological food\udchains of Red and White wines. Preliminary data indicate that 87Sr/86Sr does not change passing from grape juices to\udwine in all cases under consideration. As a corollary neither yeast nor bentonite added during vinification of both\udRed and White wines do affect their Sr-isotopic values. On the other hand, 87Sr/86Sr of Red and White wines appears\udto be significantly lower than values observed in rocks of their substrata. Further experiments performed on this\udpilot winery would be useful to shed some lights on this issue.