1,720,989 research outputs found
Special Issue: Novel Approaches for the Analytical Evaluation of Food Quality and Authenticity
Full text linkVolatile and chemical profiles of Bombino sparkling wines produced with autochthonous yeast strains
No full textThis study investigated the effects of four autochthonous yeast strains and one commercial strain of Saccharomyces cerevisiae on the volatile and chemical profiles of rosé and sparkling wines (Bombino cultivar). HPLC-HRMS, GC-MS, and odorant series analyses were performed on sparkling wine produced on an industrial scale. Statistical elaboration of GC-MS and HPLC-HRMS data suggested that the adoption of autochthonous yeast strains significantly influenced the composition of sparkling wines in terms of volatile and non-volatile compounds. A correlation analysis was performed on the GC-MS and HPLC-HRMS data to determine a pool of compounds for discrimination of winemaking processes using native versus commercial yeast strains.
The results indicated a significant strain-specific effect of the autochthonous yeast strains on the aroma and metabolome of regional sparkling wines compared to the commercial strain. This study may provide stakeholders with a powerful tool suitable to bring innovation and market differentiation
Non-targeted NMR approach to unveil and promote the biodiversity of globe artichoke in the Mediterranean area
No full textThe globe artichoke is an important constituent of the Mediterranean diet, being rich in bioactive compounds.
Artichoke is widely cultivated in Italy, especially in the Apulia region, with a multitude of local varieties. Most of
this genetic material is endangered and its metabolic profile is not yet characterized. In this work, we aimed at
dissecting landrace biodiversity by characterizing the metabolic profiles of edible hearts, i.e. the edible inner part
of the flower heads, and external bracts of artichoke flower heads, using a simple, fast, and affordable analytical
methodology. A non-targeted spectroscopic approach combining NMR experiments and multivariate data
analysis provided a comprehensive picture of the chemical composition of 16 artichoke landraces, some of which
are at risk of extinction. A special focus was on hydrosoluble compounds, contributing to the functional food
value of the artichoke. Moreover, a possible correlation between the metabolic composition and the head color
was established.
Our analyses highlight the nutraceutical diversity and value of newly studied artichoke landraces. Specifically,
the hearts of the deep purple-colored "Nero del Salento" are rich in both mono- and dicaffeoylquinic acids along
with inulin, while the hearts of the green "Bianco di Taranto" and "Centofoglie di Rutigliano" are characterized by
a relatively higher content of dicaffeoylquinic acids. The results can help promote endangered local varieties for
production and commercialization, against the ongoing genetic erosion and loss of crop diversity
Development of a food class-discrimination system by non-targeted NMR analyses using different magnetic field strengths
No full textNon-targeted NMR-based approach has received great attention as a rapid method for food product authenticity assessment. The availability of a database containing many comparable NMR spectra produced by different spectrometers is crucial to develop functional classifiers able to discriminate rapidly the commodity class of a given food product. Nevertheless, variability in spectrometer features may hamper the production of comparable spectra due to inherent variations in signal resolution. In this paper, we report on the development of a class-discrimination model for grape juice authentication by application of non-targeted NMR spectroscopy. Different approaches for the pre-treatment of data will be described along with details about the model validation. The developed model performed excellently (95.4–100% correct predictions) even when it was tested against 650 spectra produced by 65 spectrometers with different configurations (magnetic field strength, manufacturer, age). This study may boost the use of non-targeted NMR methods for food control
Optimized Sulfonated Poly(Ether Ether Ketone) Membranes for In-House Produced Small-Sized Vanadium Redox Flow Battery Set-Up
Full text linkThe ionic exchange membranes represent a core component of redox flow batteries. Their features strongly affect the performance, durability, cost, and efficiency of these energy systems. Herein, the operating conditions of a lab-scale single-cell vanadium flow battery (VRFB) were optimized in terms of membrane physicochemical features and electrolyte composition, as a way to translate such conditions into a large-scale five-cell VRFB stack system. The effects of the sulfonation degree (SD) and the presence of a filler on the performances of sulfonated poly(ether ether ketone) (SPEEK) ion-selective membranes were investigated, using the commercial perfluorosulfonic-acid Nafion 115 membrane as a reference. Furthermore, the effect of a chloride-based electrolyte was evaluated by comparing it to the commonly used standard sulfuric acid electrolyte. Among the investigated membranes, the readily available SPEEK50-0 (SD = 50%; filler = 0%) resulted in it being permeable and selective to vanadium. Improved coulombic efficiency (93.4%) compared to that of Nafion 115 (88.9%) was achieved when SPEEK50-0, in combination with an optimized chloride-based electrolyte, was employed in a single-cell VRFB at a current density of 20 mA·cm−2. The optimized conditions were successfully applied for the construction of a five-cell VRFB stack system, exhibiting a satisfactory coulombic efficiency of 94.5%
Non-Targeted NMR Method to Assess the Authenticity of Saffron and Trace the Agronomic Practices Applied for Its Production
Full text linkThe development of analytical methods aimed at tracing agri-food products and assessing their authenticity is essential to protect food commercial value and human health. An NMR-based non-targeted method is applied here to establish the authenticity of saffron samples. Specifically, 40 authentic saffron samples were compared with 18 samples intentionally adulterated by using turmeric and safflower at three different concentration levels, i.e., 5, 10, and 20 wt%. Statistical processing of NMR data furnished useful information about the main biomarkers contained in aqueous and dimethyl sulfoxide extracts, which are indicative of the presence of adulterants within the analyzed matrix. Furthermore, a discrimination model was developed capable of revealing the type of agronomic practice adopted during the production of this precious spice, distinguishing between organic and conventional cultivation. The main objective of this work was to provide the scientific community involved in the quality control of agri-food products with an analytical methodology able to extract useful information quickly and reliably for traceability and authenticity purposes. The proposed methodology turned out to be sensitive to minor variations in the metabolic composition of saffron that occur in the presence of the two adulterants studied. Both adulterants can be detected in aqueous extracts at a concentration of 5 wt%. A lower limit of detection was observed for safflower contained in organic extracts in which case the lowest detectable concentration was 20%
Exploring the xylem-sap to unravel biological features of Xylella fastidiosa subspecies pauca ST53 in immune, resistant and susceptible crop species through metabolomics and in vitro studies
Full text linkXylella fastidiosa subsp. pauca ST53 (Xfp) is a pathogenic bacterium causing one of the most severe plant diseases currently threatening the olive-growing areas of the Mediterranean, the Olive Quick Decline Syndrome (OQDS). The majority of the olive cultivars upon infections more or less rapidly develop severe desiccation phenomena, while few are resistant (e.g. Leccino and FS17), being less impacted by the infections. The present study contributes to elucidating the basis of the resistance phenomenon by investigating the influence of the composition of the xylem sap of plant species on the rate of bacterial multiplication. Xylem saps from Xfp host and non-host species were used for growing the bacterium in vitro, monitoring bacterial growth, biofilm formation, and the expression of specific genes. Moreover, species-specific metabolites, such as mannitol, quinic acid, tartaric acid, and choline were identified by non-targeted NMR-based metabolomic analysis in olive, grapevine, and citrus. In general, the xylem saps of immune species, including grapevine and citrus, were richer in amino acids, organic acids, and glucose. The results showed greater bacterial growth in the olive cultivar notoriously susceptible to Xfp (Cellina di Nardò), compared to that recorded in the resistant cultivar Leccino. Conversely, higher biofilm formation occurred in Leccino compared to Cellina di Nardò. Using the xylem saps of two Xfp-immune species (citrus and grapevine), a divergent bacterial behavior was recorded: low planktonic growth and biofilm production were detected in citrus compared to the grapevine. A parallel evaluation of the expression of 15 genes showed that Xfp directs its molecular functions mainly to virulence. Overall, the results gained through this multidisciplinary study contribute to extending the knowledge on the host-pathogen interaction, while confirming that the host response and resistance mechanism have a multifactorial basis, most likely with a cumulative effect on the phenotype
Synthesis of Functionalized Arylaziridines as Potential Antimicrobial Agents
Full text linkBy using the Suzuki-Miyaura protocol, a simple straightforward synthesis of functionalized 2-arylaziridines has been developed. By means of this synthetic strategy from readily available ortho-, meta- and para-bromophenylaziridines and aryl- or heteroarylboronic acids, new aziridines could be obtained. The cross-coupling reactions occurred without ring opening of the three membered ring. Preliminary results on the antimicrobial activity of the heterosubstituted biaryl compounds have been also included
Design, synthesis and evaluation of semi-synthetic triazole-containing caffeic acid analogues as 5-lipoxygenase inhibitors
No full textIn this work the synthesis, structure activity relationship (SAR) and biological evaluation of a novel series of triazole-containing 5-lipoxygenase (5-LO) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent 5-LO inhibition with IC50 of 0.2 and 3.2 mu M in cell-based and cell-free assays, respectively. Optimization of binding and functional potencies resulted in the identification of compound 13d, which showed an enhanced activity compared to the parent bioactive compound caffeic acid 5 and the clinically approved zileuton 3. Compounds 15 and 16 were identified as lead compounds in inhibiting 5-LO products formation in neutrophils. Their interference with other targets on the arachidonic acid pathway was also assessed. Cytotoxicity tests were performed to exclude a relationship between cytotoxicity and the increased activity observed after structure optimization
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