Evaluation of Sr isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of early potato

The talk was given at the EU Institute for Reference Materials and Measurements (IRMM) of Geel, where a collaboration is on going for the evaluation of Sr isotope abundance ratios in combination with multi-elemental analysis in the framework of the TIPIPAPA project.Apulia, Campania and Sicily are the typical Regions producing early potatoes in Italy; Potatoes produced in these two Regions are characterized by valuable quality and are not only sold in Italy, but also exported in EU (UK and Germany); Agricultural unions asked for the Protected Designation of Origin (PDO) labelling of early potatoes from Apulia, Campania and Sicily in order to protect their typical regional products; Authenticity and geographical origin of early potatoes from Apulia and Sicily need to be ensured to avoid frauds.The general aim of TIPIPAPA project is to give an answer to the need of a procedure for characterization and traceability of some early potato varieties from typical production Regions from south Italy. Aim of the research “Soil's mineralogical and geochemical characterization” leaded by Prof. Paola Adamo is to find a pool of soil-related markers which are reliable indicators for south Italy early potato geographical origin in order to avoid frauds. Main research activities are:• Climatic and pedological characterization of the typical production areas of early potato in Apulia and Sicily• Chemical, physical, mineralogical and geochemical characterization of soil from the selected production areas• multi-element and Sr-isotope ratio analyses on soil and potato samples in order to find soil-related indicators of potato's geographical originIn particular we are interested to collaborate with the IRMM of Geel for the evaluation of Sr isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of early potato. Sr mass fractions in plants are dominated by the Sr isotopic composition of labile cations in the soil, which are themselves influenced by bedrock, soil water properties and atmospheric inputs. Biological processes, whether involved in plant or animal metabolism, seem not to significantly fractionate Sr isotopes. Sr isotope ratios are expected not to undergo seasonal or annual variations. Sr isotope ratio may be a good indicator of geographical origin, provided that different lithologies exist within regions from which plants were cultivated. Mineral and trace metal composition of vegetables is a reflection of the bioavailable and mobilized elements present in the underlying soils in which plants grow. Mineral and trace element availability, depend on several soil properties (soil pH, humidity, porosity, clay and humic complexes, mineralogy, geochemistry, etc.). Mineral and trace element composition of vegetables may provide unique markers characterizing geographical origin. A single element's concentration or mass fractionation usually is not able to distinguish between samples coming from close regions with similar geological properties. Complementary analytical parameters have to be considered, evaluating isotope ratios for more elements and/or analysing major and trace elements.