1,721,042 research outputs found
Electrochemical characterization of species involved in photosynthesis: from proteins to model systems
No full textIn this paper, the results obtained in the last decade by using several electrochemical techniques to characterize species and processes involved in photosynthesis are reviewed, relating them to the work done in this field in our laboratory. The data are discussed in order of increasing level of complexity of the systems to which they are referred, going from chlorophyll aggregates to photosynthetic protein of bacteria and green plants. Possible applications of the photosynthetic systems in the field of the solar energy conversion are also described
Electronic Nose in Combination with Chemometrics for Characterization of Geographical Origin and Agronomic Practices of Table Grape
No full textNowadays, the protection of food quality attributes (such as geographical origin or method of production) from frauds and adulterations is one of the main concerns of honest producers and aware consumers. In this study, table grape samples were analyzed by using an electronic nose aiming to evaluate the usefulness of sensor data in combination with statistical analysis in discriminating the agronomic practice (conventional vs. organic farming) and the geographical origin of table grape. Principal component analysis (PCA) showed inadequate clustering of samples according to places of production or agronomic practice; thus for classification purpose, a supervised approach was carried out. In particular, linear discriminant analyses (LDA) was used, resulting in mean prediction abilities of 83.6% and 84.6% for the discrimination of farming method and geographical origin, respectively. Considering the results obtained herein, it can be concluded that sensor data combined with chemometrics showed a good potential in discriminating origin as well as method of production of table grapes especially if compared with other analytical techniques both in terms of time and cost of analyses
Characterization of the Geographical and Varietal Origin of Wheat and Bread by Means of Nuclear Magnetic Resonance (NMR), Isotope Ratio Mass Spectrometry (IRMS) Methods and Chemometrics: A Review
No full textSpectroscopic and electrochemical study of Rose Bengal in aqueous solutions of cyclodextrins
No full textThe interaction of Rose Bengal (RB) in aqueous solution of LiClO4 0.1 M with a-cyclodextrin (a-CD), hydroxypropyl-h-cyclodextrins
(HP-h-CD) and hydroxypropyl-g-cyclodextrins (HP-g-CD) were studied by spectrophotometric measurements. The presence of Induced
Circular Signals and the results of the analysis of the modifications in the absorbance spectra of RB produced by the presence of CDs in
solution indicate that RB forms inclusion complexes only with HP-h-CD and with HP-g-CD
Chemical Profile of the Carpino Broad Bean by Conventional and Innovative Physicochemical Analyses
No full textA detailed chemical characterization of a typical Apulian legume, the Carpino broad bean, was obtained. Crude proteins, moisture, phosphorus, ash and energy content were evaluated on starting seeds, half-ripening beans and final products. Stable isotope ratios (15N/14N and 13C/12C), major (Ca, Mg, Na and K) and trace metals (Zn, Mo, Mn, Cu, Fe, Cr, Cd, Ni and Co) were also assessed. Moreover, information on a large number of metabolites was obtained by 1H high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy. The data revealed that Carpino broad bean dry seeds supply adequate protein and energy content, 28.1% and 326kcal, respectively, being also a good source of macro- and microelements. In particular, the iron content was 46.0mg/kg: this potentially provides about 33% of the recommended daily allowance by a 100g serving. Moreover, the analyzed samples seem to lack elements considered potentially harmful for health. Practical Applications: The Carpino broad bean is a native faba bean cultivar, traditionally cultivated in small quantities in Gargano (Southern Italy). It is commonly considered a traditional food product with interesting nutritional properties. At present, the Carpino broad bean has still not received an official European label as typical product, but it is a Slow Food presidium, this remarks its considerable socio-cultural, nutritional and environmental values. Even if restricted to a limited geographic area, this typical and appreciable cultivation should be protected from extinction, preserving territory identity and working techniques; therefore, it is essential to explore ways to prove the Carpino broad bean quality and peculiarities, starting from a physicochemical characterization, that has not been presented in detail until now, and that could be a considerable basis for an official valorization of this product, for instance, for the attainment of EU Protected Designation of Origin/Protected Geographical Indication (EU PDO/PGI) labels
Electrochemical characterization of the fluorescent 2-(bis-(β-hydroxyethyl)-amino)-1.4-benzoquinone
No full textBiomaterials based on photosynthetic membranes as potential sensors for herbicides
No full textIn this study, ultrathin film multilayers of Photosystem II-enriched photosynthetic membranes (BBY) were prepared and immobilized on quartz substrates by means of a Layer by Layer procedure exploiting electrostatic interactions with poly(ethylenimine) as polyelectrolyte. The biomaterials thus obtained were characterized by means of optical techniques and Atomic Force Microscopy, highlighting the fact that the Layer by Layer approach allowed the BBYs to be immobilized with satisfactory results. The activity of these hybrid materials was evaluated by means of optical assays based on the Hill Reaction, indicating that the biosamples, which preserved about 65% of their original activity even ten weeks after preparation, were both stable and active. Furthermore, an investigation of the biochips’ sensitivity to the herbicide terbutryn, as a model analyte, gave interesting results: inhibition of photosynthetic activity was observed at terbutryn concentrations higher than 10-7 M, thus evidencing the potential of such biomaterials in the environmental biosensor field
Caratterizzazione dell’origine geografica di patate italiane basata su analisi di isotopi stabili e composti volatili
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