Abstract
Several chemical and isotopic methods have been suggested for tracing the wine origin in relation to the climate/meteorological conditions of the vineyard areas. IRMS (Isotope Ratio Mass Spectrometer) is one of these tools. In the Oltrepò Pavese (Lombardia Region, Pavia Province, Italy) and in the Illasi/Mezzane areas (Veneto Region, Verona Province, Italy), for the harvests of 2021 and 2022, a linear correlation between δ (18)O of the grape must water (δ (18)O(m)) and the potential evapotranspiration (ET(O)) and crop evapotranspiration (ET(C)) has been found. ET(O) and ET(C) were calculated according to the FAO-56 model using meteorological data from the meteorological stations located close to the vineyards studied. We can state that the intercept obtained for the linear correlation δ (18)O(m) on ET(C) is an estimate of the isotopic features of the water absorbed by plants during the late stage of the grape ripening. The obtained data allowed us to estimate the isotopic enrichment factor ε (18)O(m-PW) (m = grape must water and PW = precipitation water), which depends on climatic/meteorological conditions. Subsequently, the climatic parameters that mostly influence the oxygen isotope variation in grape must water have been identified using a correlation coefficient.