Combined approach of EPR and PCA analysis as a tool for clustering soils and leaves of olive groves and vineyards of different geographical origin

The Electron Paramagnetic Resonance (EPR) technique can be used to study agri-food matrices. This versatile technique provides specific insights into paramagnetic centres without requiring sample treating. In this paper, the EPR spectroscopy has been employed to investigate soils and leaves from vineyards and olive groves. A total of 33 soils and 31 leaves samples from olive groves, along with 53 soils and 19 leaves samples from vineyards, were collected from nearby areas in the south of Tuscany region (Italy). The EPR spectra of soils and leaves were analyzed both quantitatively and qualitatively on the basis of paramagnetic metal ions like manganese, iron and free radicals. A first classification was performed quantifying the different amounts of manganese signal in the samples. Nevertheless, the combined use of the EPR analysis with multivariate techniques like Principal Component Analysis (PCA), provides us a novel and fast tool for clustering samples on the basis of their geographical origin.