Université de Nîmes, France
Posters-Accepted Abstracts: J Food Process Technol
Recent works have proposed identification of the geographical origin of some food products through the analysis of their strontium (Sr) isotopes signature. Sr is a natural element found in rocks, soil and water in varying concentrations, on the order of 300 μg.g- 1. The distribution of its isotopes (assessed through monitoring of 87Sr/86Sr ratios) in these reservoirs is specific of the geological environment (type of rock, age, geological history). The Sr element is also found in plants although at generally lower levels (on the order of 20 μg.g-1). Based on the assumption that the transfer of Sr from soil to plants takes place without changing isotope ratios, various approaches have been proposed to identify the geographical origin of plant products by determining their 87Sr/86Sr ratio, which might reflect the values observed in the soil. The purpose of this study is to assess the feasibility of Sr extraction from a complex matrix such as olive oil, and to carry out isotopic measurements to implement a geographical identification approach of olive oils using Sr isotopes. Existing protocols for purification of Sr are unsuitable due to the viscosity, high organic load and low strontium content of the lipid matrix (1.5 ng g-1and 50 ng g-1) coupled with the hydrophilic nature of Sr. Therefore, the first approach proposed here involved setting up a methodology for olive oil treatment for Sr extraction. After validation, the protocol is applied to test a geographical identification of a PDO Nimes�?? oil by comparison with two Moroccan oils.