Metabolomic approach in the study of foods by high-resolution liquid state NMR and HPLC techniques

Foodstuffs and medicinal plants are complex matrices characterized by a diverse and rich chemical composition, strongly influenced by cultivation practices, storage conditions, and processing treatments. A comprehensive analytical approach is therefore required to achieve an exhaustive characterization, and in this context omics sciences — particularly metabolomics — represent a powerful strategy. Among these, Nuclear Magnetic Resonance (NMR) spectroscopy stands out as a robust and reproducible technique capable of addressing several food-related issues, including compositional profiling, authentication of variety and geographical origin, and detection of potential adulterations. This PhD research employed NMR-based metabolomics, often integrated with targeted HPLC analyses, to investigate a wide range of food and plant matrices. The first line of research focused on the valorization of Italian local products through the chemical profiling of ancient apple cultivars from the Piedmont region, tomato varieties from Lazio, and Goji berries cultivated under local conditions. A second study explored the preservation of pumpkin samples stored with different biofilm materials, revealing that PLA packaging maintained the metabolite profile most effectively over time. A third research topic investigated Cannabis sativa L.-derived products, including inflorescences grown under different agronomic practices and commercial hempseed oils, for which the ω-6/ω-3 ratio was proposed as a quality index measurable by NMR. Finally, the aerial parts of Gentiana lutea L. were characterized by NMR and HPLC-PDA, revealing flowers as rich sources of secondary metabolites and leaves as particularly abundant in iridoids and xanthones, suggesting potential applications in the formulation of functional foods and bioactive extracts. Overall, this work highlights the versatility and analytical power of NMR-based metabolomics, supported by complementary chromatographic approaches, as an effective tool for the comprehensive characterization, valorization, and quality assessment of agri-food and medicinal plant matrices.