title: Soil properties, strontium isotopic signatures and multi-element profiles to authenticate the origin of vegetables from small-scale regions: illustration with early potatoes from southern Italy.
abstract: We propose a method for the authentication of the origin of vegetables grown under similar weather conditions, in sites less than 10 km distance from the sea and distributed over a rather small scale area (58651 km(2)). We studied how the strontium (Sr) isotopic signature and selected elemental concentrations ([Mn], [Cu], [Zn], [Rb], [Sr] and [Cd]) in early potatoes from three neighbouring administrative regions in the south of Italy were related to the geological substrate (alluvial sediments, volcanic substrates and carbonate rocks) and to selected soil chemical properties influencing the bioavailability of elements in soils (pH, cation exchange capacity and total carbonate content). Through multiple-step multivariate statistics (PLS-DA) we could assign 26 potatoes (including two already commercialised samples) to their respective eight sites of production, corresponding to the first two types of geological substrates. The other 12 potatoes from four sites of production had similar characteristics in terms of the geological substrate (third type) and these soil properties could be grouped together. In this case, more discriminative parameters would be required to allow the differentiation between sites. The validation of our models included external prediction tests with data of potatoes harvested the year before and a study on the robustness of the uncertainties of the measurement results. Annual variations between multi-elemental and Sr isotopic fingerprints were observed in potatoes harvested from soils overlying carbonate rocks, stressing the importance of testing long term variations in authentication studies.
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Geel, Belgium.
authors.forename: Mariavittoria
authors.initials: M
authors.lastname: Zampella
authors.forename: Christophe R
authors.initials: CR
authors.lastname: Quétel
authors.forename: Eduardo
authors.initials: E
authors.lastname: Paredes
authors.forename: Daniel
authors.initials: D
authors.lastname: Goitom Asfaha
authors.forename: Simona
authors.initials: S
authors.lastname: Vingiani
authors.forename: Paola
authors.initials: P
authors.lastname: Adamo
mesh_terms: D002254:Carbonates / Q000737:chemistry; D016002:Discriminant Analysis; D005843:Geography; D006863:Hydrogen-Ion Concentration; D007558:Italy; D016018:Least-Squares Analysis; D019216:Metals, Heavy / Q000032:analysis*; D008956:Models, Chemical; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D012987:Soil / Q000737:chemistry*; D011198:Solanum tuberosum / Q000737:chemistry*; D013324:Strontium / Q000032:analysis* / Q000737:chemistry; D013325:Strontium Isotopes / Q000032:analysis
chemical_list: D002254:Carbonates; D019216:Metals, Heavy; D012987:Soil; D013325:Strontium Isotopes; D013324:Strontium