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To differentiate extra virgin olive oils (EVOO) according to the origin of purchase, such as monocultivar Italian EVOO with protected denomination of origin (PDO) and commercially-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of various lipid species by liquid chromatography/mass spectrometry (LC-ESI-MS/MS, LC-ESI-IT-MS) and proton nuclear magnetic resonance analysis ( 1 H-NMR). Many putative chemical markers were extracted as differentiators by uni- and multivariate statistical analysis. Commercially-blended EVOO contained higher concentrations of the majority of minor lipids, including free fatty acids, their alkyl (methyl and ethyl) esters, monoglycerides, and diglycerides, which may be indicative of a higher degree of triglyceride lipolysis in these than in monocultivar PDO EVOO. Triterpenoids and particular TAG species were also found in higher proportions in the samples from the commercially-blended EVOO class, suggesting a possible influence of factors such as the cultivar and geographical origin. The largest differences between the classes were determined for the concentrations of uvaol and oleanolic acid. The results of the analysis by isotopic ratio mass spectrometry (IRMS) were reasonably consistent with the information about the geographical origin declared on the labels of the investigated EVOOs, showing considerable variability, which possibly also contributed to the differences in lipid composition observed between the two investigated classes of EVOO.

In order to differentiate the extra virgin olive oils (EVOO) of different origin of purchase, such as monovarietal Italian EVOO with protected denomination of origin (PDO) and commercial-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of volatile aroma compounds by both targeted gas chromatography/mass spectrometry (GC-MS) and untargeted profiling by comprehensive two-dimensional gas chromatography/mass spectrometry (GC×GC-TOF-MS), analysis of phenols by targeted high-performance liquid chromatography/mass spectrometry (HPLC-DAD-ESI/MS), and quantitative descriptive sensory analysis. Monovarietal PDO EVOOs were characterized by notably higher amounts of positive LOX-derived C6 and C5 volatile compounds, which corresponded to the higher intensities of all the assessed positive fruity and green odor sensory attributes. Commercial-blended EVOOs had larger quantities of generally undesirable esters, alcohols, acids, and aldehydes, which coincided with the occurrence of sensory defects in many samples. Many minor volatile compounds that were identified by GC×GC-TOF-MS were found to differentiate each of the two investigated groups. The differences between the groups with respect to phenols and taste characteristics were evident, but less pronounced. The results that were obtained in this study have undoubtedly confirmed the existence of the large heterogeneity of oils that are sold declared as EVOO. It was shown that GC-MS, GC×GC-TOF-MS, and HPLC-DAD-ESI/MS analyses have complementary outputs, and that their use in combination has advantages in supporting the results of sensory analysis and objectively differentiating these groups of EVOO.

Purpose: Olive pomace is a major waste product of olive oil production but remains rich in polyphenols and fibres. We measured the potential of an olive pomace-enriched biscuit formulation delivering 17.1 ± 4.01 mg/100 g of hydroxytyrosol and its derivatives, to modulate the composition and metabolic activity of the human gut microbiota.Methods: In a double-blind, controlled parallel dietary intervention 62 otherwise healthy hypercholesterolemic (total plasma cholesterol 180-240 mg/dl) subjects were randomly assigned to eat 90 g of olive pomace-enriched biscuit (olive-enriched product, OEP) or an isoenergetic control (CTRL) for 8 weeks. Fasted blood samples, 24-h urine and faecal samples were collected before and after dietary intervention for measurement of microbiota, metabolites and clinical parameters.Results: Consumption of OEP biscuits did not impact on the diversity of the faecal microbiota and there was no statistically significant effect on CVD markers. A trend towards reduced oxidized LDL cholesterol following OEP ingestion was observed. At the genus level lactobacilli and Ruminococcus were reduced in OEP compared to CTRL biscuits. A trend towards increased bifidobacteria abundance was observed after OEP ingestion in 16S rRNA profiles, by fluorescent in situ hybridization and by qPCR. Targeted LC-MS revealed significant increases phenolic acid concentrations in 24-h urine following OEP ingestion and 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid, derivatives of hydroxytyrosol, were elevated in blood. A sex effect was apparent in urine small phenolic acid concentrations, and this sex effect was mirrored by statistically significant differences in relative abundances of faecal bacteria between men and women.Conclusion: Ingestion of OEP biscuits led to a significant increase in the metabolic output of the gut microbiota with an apparent sex effect possibly linked to differences in microbiota makeup. Increased levels of homovanillic acid and DOPAC, thought to be involved in reducing oxidative LDL cholesterol, were observed upon OEP ingestion. However, OEP did not induce statistically significant changes in either ox-LDL or urinary isoprostane in this study. [ABSTRACT FROM AUTHOR]

To differentiate extra virgin olive oils (EVOO) according to the origin of purchase, such as monocultivar Italian EVOO with protected denomination of origin (PDO) and commercially-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of various lipid species by liquid chromatography/mass spectrometry (LC-ESI-MS/MS, LC-ESI-IT-MS) and proton nuclear magnetic resonance analysis (1H-NMR). Many putative chemical markers were extracted as differentiators by uni- and multivariate statistical analysis. Commercially-blended EVOO contained higher concentrations of the majority of minor lipids, including free fatty acids, their alkyl (methyl and ethyl) esters, monoglycerides, and diglycerides, which may be indicative of a higher degree of triglyceride lipolysis in these than in monocultivar PDO EVOO. Triterpenoids and particular TAG species were also found in higher proportions in the samples from the commercially-blended EVOO class, suggesting a possible influence of factors such as the cultivar and geographical origin. The largest differences between the classes were determined for the concentrations of uvaol and oleanolic acid. The results of the analysis by isotopic ratio mass spectrometry (IRMS) were reasonably consistent with the information about the geographical origin declared on the labels of the investigated EVOOs, showing considerable variability, which possibly also contributed to the differences in lipid composition observed between the two investigated classes of EVOO. [ABSTRACT FROM AUTHOR]