Application of nuclear magnetic resonance spectroscopy in the study of complex matrices

The aim of this PhD work was to apply the NMR based metabolomic approach to the study of complex matrices such as several food plants (pepper, celery, tomatoes, hemp, baobab, teas, blueberries and olive oils). A comprehensive description of the chemical composition in term of primary and secondary metabolites obtained by means of 1D and 2D experiments was reported and information regarding specific aspects (variety, type of production etc) were obtained. The study of stool samples of patients with liver cirrhosis was also carried out confirming the important contribution of the NMR approach in the disease investigation

A multi-methodological protocol to characterize PDO olive oils

An analytical approach including Panel Test, Isotope Ratio Mass Spectrometry (IRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy was proposed to characterize Italian “Colline Pontine” PDO olive oils (40 samples) of two consecutive crop years. Our approach has evidenced the high quality of these olive oils. Only 6 of 40 olive oils samples were defined as “defective” by the official Panel Test due to the detection of negative sensory attributes. The low variability of isotopic data monitored by IRMS confirmed that the olive oil samples all came from a limited geographical area. NMR spectra did not evidence any chemical composition anomaly in the investigated samples. In order to assess the influence of harvesting year over the olive oil chemical composition, the NMR analysis was extended to other 22 olive oil samples of a third harvesting year. NMR data were submitted to two different statistical methods, namely, analysis of variance (ANOVA) and principal component analysis (PCA) allowing olive oils of three consecutive harvesting years to be grouped

A Multi-Methodological Protocol to Characterize PDO Olive Oils

An analytical approach including Panel Test, Isotope Ratio Mass Spectrometry (IRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy was proposed to characterize Italian “Colline Pontine” PDO olive oils (40 samples) of two consecutive crop years. Our approach has evidenced the high quality of these olive oils. Only 6 of 40 olive oils samples were defined as “defective” by the official Panel Test due to the detection of negative sensory attributes. The low variability of isotopic data monitored by IRMS confirmed that the olive oil samples all came from a limited geographical area. NMR spectra did not evidence any chemical composition anomaly in the investigated samples. In order to assess the influence of harvesting year over the olive oil chemical composition, the NMR analysis was extended to other 22 olive oil samples of a third harvesting year. NMR data were submitted to two different statistical methods, namely, analysis of variance (ANOVA) and principal component analysis (PCA) allowing olive oils of three consecutive harvesting years to be grouped

Caratterizzazione della faina di canapa (Cannabis sativa L.): profilo metabolomico e composti bioattivi

La canapa industriale è una pianta versatile e può essere utilizzata per scopi alimentari o nutraceutici. Ogni parte della canapa può essere utilizzata nell'alimentazione (le foglie per la preparazione di prodotti da forno: torte, pane, etc.; i semi per produrre olio commestibile e farina). La farina di canapa contiene tutti gli otto aminoacidi essenziali ed è caratterizzata da un rapporto di acidi grassi polinsaturi ω-3/ω-6, ottimale per la salute umana. La farina di canapa è priva di glutine, ricca di fibre e possiede un 21% di calorie in meno rispetto alle farine comuni. Tutte queste caratteristiche la rendono un alimento “funzionale” per chi ha bisogno di diete particolari e per questo può essere utilizzata per produrre pasta e pane, in cui può essere incorporata dal 5% al ​​20%. Questo studio si propone di caratterizzare mediante un approccio multi-metodologico un campione di farina di canapa ottenuto dai semi di piante della cultivar USO31, coltivate presso il comune di Allumiere (RM). E’ stata effettuata un'analisi “untargeted” mediante Risonanza Magnetica Nucleare (NMR) ad alto campo che ha permesso di ottenere il profilo metabolomico della farina in esame. Inoltre, un successivo approccio “targeted” è stato applicato per la determinazione di composti bioattivi (ammine biogene e composti antiossidanti), importanti per la valutazione della qualità degli alimenti

Caratterizzazione della farina di Canapa (Cannabis Sativa L.): profilo metabolomico e composti bioattivi

La canapa industriale è una pianta versatile e può essere utilizzata per scopi alimentari o nutraceutici. Ogni parte della canapa può essere utilizzata nell'alimentazione (le foglie per la preparazione di prodotti da forno: torte, pane, etc.; i semi per produrre olio commestibile e farina). La farina di canapa contiene tutti gli otto aminoacidi essenziali ed è caratterizzata da un rapporto di acidi grassi polinsaturi ω-3/ω-6, ottimale per la salute umana. La farina di canapa è priva di glutine, ricca di fibre e possiede un 21% di calorie in meno rispetto alle farine comuni. Tutte queste caratteristiche la rendono un alimento “funzionale” per chi ha bisogno di diete particolari e per questo può essere utilizzata per produrre pasta e pane, in cui può essere incorporata dal 5% al ​​20%. Questo studio si propone di caratterizzare mediante un approccio multi-metodologico un campione di farina di canapa ottenuto dai semi di piante della cultivar USO31, coltivate presso il comune di Allumiere (RM). E’ stata effettuata un'analisi “untargeted” mediante Risonanza Magnetica Nucleare (NMR) ad alto campo che ha permesso di ottenere il profilo metabolomico della farina in esame. Inoltre, un successivo approccio “targeted” è stato applicato per la determinazione di composti bioattivi (ammine biogene e composti antiossidanti), importanti per la valutazione della qualità degli alimenti

Panel test and chemical analyses of commercial olive oils: a comparative study

Background: The quality grade of an olive oil is defined according to the results of analytical and organoleptic examinations.The increasing attention towards both olive oil quality and quality verification methods prompted us to undertake a “critical” analysis of analytical and sensory data supplied by an International Certificated Body (ICB), relative to commercial olive oils produced in Mediterranean areas and purchased in Italy and in USA. Methods: ICB data included chemical analyses namely free acidity, peroxide index, spectrophotometric UV evaluation, fatty acid ethyl esters and stigmadiens content and organoleptic evaluations carried out by nine official International Olive Council labs according to EEC Regulation 2568/91. Results: The results of the chemical analyses, except the fatty acid ethyl ester content, obtained from the nine labs were consistent giving rise to the same quality grade. In nearly all samples, the fatty acid ethyl ester content was close to the threshold established for extra virgin olive oils indicating a non-excellent quality of the olive oils. Organoleptic evaluations, commonly called panel test, given by the nine labs were not consistent. Conclusions: The EEC Regulation 2568/91 does not give any indication on the way to report the uncertainty of the results, and in the case of extra virgin olive oils with a borderline value, the way to report the fatty acid ethyl ester content, with or without the uncertainty, can create confusion in defining the olive oil quality grade. Panel test seemed to work well only in the case of extremely good olive oils, whereas, in commercial extra virgin olive oils with borderline value of fatty acid ethyl ester content, a different sensory sensibility seems to be in the different IOC labs

Panel test and chemical analyses of commercial olive oils: a comparative study

Background: The quality grade of an olive oil is defined according to the results of analytical and organoleptic examinations.The increasing attention towards both olive oil quality and quality verification methods prompted us to undertake a “critical” analysis of analytical and sensory data supplied by an International Certificated Body (ICB), relative to commercial olive oils produced in Mediterranean areas and purchased in Italy and in USA. Methods: ICB data included chemical analyses namely free acidity, peroxide index, spectrophotometric UV evaluation, fatty acid ethyl esters and stigmadiens content and organoleptic evaluations carried out by nine official International Olive Council labs according to EEC Regulation 2568/91. Results: The results of the chemical analyses, except the fatty acid ethyl ester content, obtained from the nine labs were consistent giving rise to the same quality grade. In nearly all samples, the fatty acid ethyl ester content was close to the threshold established for extra virgin olive oils indicating a non-excellent quality of the olive oils. Organoleptic evaluations, commonly called panel test, given by the nine labs were not consistent. Conclusions: The EEC Regulation 2568/91 does not give any indication on the way to report the uncertainty of the results, and in the case of extra virgin olive oils with a borderline value, the way to report the fatty acid ethyl ester content, with or without the uncertainty, can create confusion in defining the olive oil quality grade. Panel test seemed to work well only in the case of extremely good olive oils, whereas, in commercial extra virgin olive oils with borderline value of fatty acid ethyl ester content, a different sensory sensibility seems to be in the different IOC labs

Combining Amplicon Sequencing and Metabolomics in Cirrhotic Patients Highlights Distinctive Microbiota Features Involved in Bacterial Translocation, Systemic Inflammation and Hepatic Encephalopathy

In liver cirrhosis (LC), impaired intestinal functions lead to dysbiosis and possible bacterial translocation (BT). Bacteria or their byproducts within the bloodstream can thus play a role in systemic inflammation and hepatic encephalopathy (HE). We combined 16S sequencing, NMR metabolomics and network analysis to describe the interrelationships of members of the microbiota in LC biopsies, faeces, peripheral/portal blood and faecal metabolites with clinical parameters. LC faeces and biopsies showed marked dysbiosis with a heightened proportion of Enterobacteriaceae. Our approach showed impaired faecal bacterial metabolism of short-chain fatty acids (SCFAs) and carbon/methane sources in LC, along with an enhanced stress-related response. Sixteen species, mainly belonging to the Proteobacteria phylum, were shared between LC peripheral and portal blood and were functionally linked to iron metabolism. Faecal Enterobacteriaceae and trimethylamine were positively correlated with blood proinflammatory cytokines, while Ruminococcaceae and SCFAs played a protective role. Within the peripheral blood and faeces, certain species (Stenotrophomonas pavanii, Methylobacterium extorquens) and metabolites (methanol, threonine) were positively related to HE. Cirrhotic patients thus harbour a 'functional dysbiosis' in the faeces and peripheral/portal blood, with specific keystone species and metabolites related to clinical markers of systemic inflammation and HE