Use of Liquid Chromatography and Mass Spectrometry Methods for the Detailed Characterization of Food and Biological Samples

The pivotal role of analytical chemists in ensuring food quality and safety cannot be understated, as they are tasked with safeguarding public health by meticulously analyzing food samples for the detection of contaminants and adulterants. Liquid chromatography (LC) and mass spectrometry (MS) stand as indispensable techniques in this pursuit, offering unparalleled capabilities for the identification and quantification of diverse analytes. Throughout my doctoral research, LC-MS and Ambient MS (AMS) methodologies, such as Direct Analysis in Real Time (DART) and Rapid Evaporative Ionization Mass Spectrometry (REIMS) were employed to investigate the composition of various food products and biological matrices, leveraging their high sensitivity, selectivity, and versatility to identify and quantify a wide range of analytes (lipids, carotenoids, phenolic compounds). Specifically, using LC-MS techniques, mainly unconventional oils were characterized. An initial work focused on the comprehensive chemical characterization of prickly pear seed oils, while a subsequent study characterized various unconventional seed oils (blackcurrant, carrot, plum, pomegranate, radish, raspberry, rosehip, strawberry). Moreover, a cost-effective and user-friendly approach has been developed using the DART source coupled with a compact single quadrupole MS analyzer, to characterize major and minor compounds in high-quality Extra Virgin Olive Oils (EVOOs). An untargeted approach based on the analysis of EVOOs in their native form and a targeted method involving a solid phase microextraction (SPME) of phenolic compounds prior of the analysis, were explored. Moreover, MS spectra were collected into a spectral database and chemometric tools were applied to build statistical models useful to clusterize and classify EVOOs according to geographical origin and cultivar, as main factors determining their nutritional and sensory profiles. Furthermore, during the PhD period abroad at Prague University of Chemistry and Technology (Prague, Czech Republic) the phenol profiles of 19 distinct chili pepper varieties cultivated in Italy were comprehensively elucidated through Ultra-High-Performance Liquid Cromatography High Resolution Mass Spectrometry (UHPLC-HRMS). Moreover, “in-house” developed assays were performed to evaluate any bioactivity potential based on the activity of acetylcholinesterase butyrylcoholinasterase, pancreatic lipase, α-glucosidase and tyrosinase. Additionally, the total antioxidant capacity and the total phenolic content were measured using a 2,2-Diphenyl-1-picrylhydrazyl assay and a Folin–Ciocalteu assay, respectively. Lastly, REIMS coupled to a monopolar handpiece used for surgical resection and combined with chemometrics was employed to distinguish between benign and malignant canine mammary tumours, facilitating a more in-depth investigation of changes in cellular metabolic phenotype during neoplastic transformation.