Geotraceability of Falanghina del Sannio (South Italy): Preliminary mineralogical and isotopic data.

ABSTRACT

The present study gathers mineralogical and isotopic geochemical data of 45 soil samples collected from the La Guardiense and Cantina di Solopaca wineries (Southern Italy) in order to provide useful information for the geotraceability of Falanghina white wine terroir. Mineralogical analyses show the ubiquitous presence of quartz, frequent and moderate contents of feldspars and phyllosilicates (i.e., illite/mica, kaolinite, and smectite). Rhizosphere soils from La Guardiense vineyards show a strontium isotope signature (87Sr/86Sr) ranging from 0.708604 to 0.711234 (average 0.710334; 1σ = 0.000943; n = 7) for the total fraction and a narrower range (from 0.706907 to 0.708807; average 0.708120; 1σ = 0.000641; n = 7) for the bioavailable one. For the rhizosphere soils collected from the vineyards of Cantina di Solopaca winery, 87Sr/86Sr ratios range from 0.708268 to 0.712413 (average 0.710145; 1σ = 0.001622; n = 8) and from 0.707968 to 0.709157 (average 0.708384; 1σ = 0.000409; n = 8) for the total and the bioavailable fraction, respectively. Actually, the bioavailable Sr fraction shows a narrower range of 87Sr/86Sr ratios compared to that of the total fraction, making the former more suitable for any study of wine traceability.