Metabolomics is the scientific discipline that identifies and quantifies endogenous andexogenous metabolites in different biological samples. Metabolites are crucial componentsof a biological system and they are highly informative about its functional state, due to theircloseness to the organism’s phenotype. This approach finds an increasing number ofapplications in many areas including medical, pharmaceutical, food and environmentalsciences. The combined use of NMR spectroscopy and chemometrics techniques, is able toprovide the metabolic “fingerprint” of the various samples.This PhD project focused on the analysis of various samples covering a wide range offields, namely, food and nutraceutical sciences, cell metabolomics and medicine using ametabolomics approach. Indeed, the first part of the thesis describes two exploratory studiesperformed on Algerian extra virgin olive oil and apple juice from ancient Danish applecultivars. Both studies revealed variety-related peculiarities that would have been difficultto detect by means of traditional analysis. The second part of the project includes fourmetabolomics studies performed on samples of biological origin. In particular, the firststudy is related to a recent emerging field: cell metabolomics. Indeed, tumour cells(HTC116) were treated with novel anticancer drugs in order to understand their in vitroaction. The aim of this study was also the development of a reliable experimental protocolfor an efficient harvesting, quenching and extraction of cellular metabolites of humanadherent cancer cell lines.The second and the third studies concern the evaluation of the effects of functional foodingredients, namely β-glucans and phytosterols, on in vivo animal models. In particular, thehypocholesterolemic action of β-glucans was investigated by analysing rat plasma andfaecal samples. This study confirmed the role of barley β-glucans in increasing faecal bileacids excretion in hypercholesterolemic rats and showed, for the first time, a modulation ofthe primary and secondary bile acid excretion, depending on the molecular weight of the β-glucan employed. In the other study, the effects of phytosterols on a murine colitis model,was investigated. NMR measurements on the liver metabolome revealed the role of theseplant sterols in restoring the homeostatic equilibrium of the living system. Thus, in bothcases, the results suggest the appropriate use of these nutraceutical products. The last studyexplores the differences in the follicular fluid metabolome of hyper- and normoinsulinemicwomen affected with Polycystic Ovary Syndrome (PCOS). The study provides preliminarybut interesting relationships between serum hormones and metabolites in follicular fluids.