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ABSTRACT: (1)H High Resolution Magic Angle Spinning-Nuclear Magnetic Resonance (HRMAS-NMR) spectroscopy was used to analyse garlic (Allium sativum L.) belonging to red and white varieties and collected in different Italian regions, in order to address the traceability issue. 1D and 2D NMR spectra, performed directly on untreated small pieces of garlic, so without any sample manipulation, allowed the assignment of several compounds: organic acids, sugars, fatty acids, amino acids and the nutritionally important fructo-oligosaccharides and allyl-organosulphur compounds. Application of Partial Least Squares projections to latent structures-Discrimination Analysis provided an excellent model for the discrimination of both the variety and, most important, the place origin, allowing the identification of the metabolites contributing to such classifications. The presence of organosulphurs, allicin and some allyl-organosulphurs found by HRMAS-NMR, was confirmed also by SPME-GC-MS; 11 molecules were identified, containing from one up to three sulphur atoms and with and without allyl moieties.
Food Chemistry 11/2012; 135(2):684-93. · 3.65 Impact Factor
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ABSTRACT: BACKGROUND: Analytical traceability of PGI and PDO foods (Protected Geographical Indication and Protected Denomination Origin respectively) is one of the most challenging tasks of current applied research. RESULTS: Here we proposed a metabolomic approach based on the combination of (1) H high-resolution magic angle spinning-nuclear magnetic resonance (HRMAS-NMR) spectroscopy with multivariate analysis, i.e. PLS-DA, as a reliable tool for the traceability of Italian PGI chicories (Cichorium intybus L.), i.e. Radicchio Rosso di Treviso and Radicchio Variegato di Castelfranco, also known as red and red-spotted, respectively. The metabolic profile was gained by means of HRMAS-NMR, and multivariate data analysis allowed us to build statistical models capable of providing clear discrimination among the two varieties and classification according to the geographical origin. CONCLUSION: Based on Variable Importance in Projection values, the molecular markers for classifying the different types of red chicories analysed were found accounting for both the cultivar and the place of origin. © 2012 Society of Chemical Industry.
Journal of the Science of Food and Agriculture 11/2012; · 1.44 Impact Factor
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ABSTRACT: (1)H-high resolution magic angle spinning-nuclear magnetic resonance spectroscopy was employed to gain the metabolic profile of longissimus dorsi and semitendinosus muscles of four different breeds: Chianina, Holstein Friesian, Maremmana and Buffalo. Principal component analysis, partial least squares projection to latent structure - discriminant analysis and orthogonal partial least squares projection to latent structure - discriminant analysis were used to build models capable of discriminating the muscle type according to the breed. Data analysis led to an excellent classification for Buffalo and Chianina, while for Holstein Friesian the separation was lower. In the case of Maremmana the use of intelligent bucketing was necessary due to some resonances shifting allowed improvement of the discrimination ability. Finally, by using the Variable Importance in Projection values the metabolites relevant for the classification were identified.
Meat Science 06/2012; 92(4):754-61. · 2.28 Impact Factor
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ABSTRACT: High resolution magic angle spinning, that is, HRMAS, is a quite novel tool in NMR spectroscopy; it offers the almost unique opportunity of measuring intact tissues disguised as suspended or swollen in a deuterated solvent. The feasibility of (1)H-HRMAS-NMR in foodstuff characterisation has been exploited, but in spite of this, its applications are still limited. Metabolic profiling and biopolymer composition and aggregation are the topics investigated until now for raw vegetables, meat and processed foodstuff. Almost all known studies are reported in the next pages.
Magnetic Resonance in Chemistry 12/2011; 49 Suppl 1:S121-5. · 1.44 Impact Factor
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ABSTRACT: HRMAS-NMR spectroscopy was used to assess the metabolic profile of sweet pepper (Capsicum Annum L.). One-dimensional and two-dimensional NMR spectra, performed directly on sample pieces of few milligrams, hence without any chemical and/or physical manipulation, allowed the assignment of several compounds. Organic acids, fatty acids, amino acids, and minor compounds such as trigonelline, C4-substituted pyridine, choline, and cinnamic derivatives were observed with a single experiment. A significant discrimination between the two sweet pepper varieties was found by using partial least-squares projections to latent structures discrimination analysis (PLS-DA). The metabolites contributing predominantly to such differentiation were sugars and organic and fatty acids. Also a partial separation according to the geographical origin was obtained always by analyzing the NMR data with PLS-DA. Some of the discriminating molecules are peculiar for pepper and contribute to define the overall commercial and organoleptic quality so that HRMAS-NMR proved to be a complementary analysis to standard tools used in food science and, in principle, can be applied to any foodstuff.
Journal of Agricultural and Food Chemistry 09/2010; 58(17):9675-84. · 2.82 Impact Factor
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ABSTRACT: The present study investigated the effects of using arsenic (As) contaminated irrigation water in Lactuca sativa L. cropping. Two different arsenic concentrations, i.e., 25 and 85 μg L(-1) and two different soils, i.e., sandy and clay loam, were taken into account. We determined the arsenic mobility in the different soil fractions, its amount in groundwater, and the phytotoxicity and genotoxicity. Nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP) were used to assess the lettuce metabolic profile changes and the arsenic uptake by the plant, respectively, as a function of the various conditions studied, i.e., As content and type of soil. Data indicated that at both concentrations in sandy soil, arsenic is in part quickly leached and thus present in groundwater and in part absorbed by the vegetable, being therefore readily available for assimilation by consumption. NMR results reported a large modification of the metabolic pattern, which was depending on the pollutant amount. In clay loam soil, the groundwater had a low As content with respect to sandy soil, and NMR and ICP performed on the lettuce did not reveal severe changes related to As, most likely because the metalloid is bound to the colloidal fraction.
Biological trace element research 09/2010; 143(1):518-29. · 1.92 Impact Factor
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ABSTRACT: Arsenic (As) is a highly toxic element and its presence in food is a matter of concern for the well-being of both animals and humans. Arsenic-contaminated groundwater is used in agriculture to irrigate crops for food and animal consumption with a potential contamination of the food chain. The purpose of this study was the evaluation of arsenic effect on radish tuber (Raphanus sativus L.). Experimental plots with sandy and clay-loamy soil were cultivated with radish and treated with three different concentrations of As water solution: 19, 44 and 104 µg/L. Magnetic resonance imaging was used to visualize the tuber structural changes, and the content of elements and the As amount were evaluated by inductively coupled plasma atomic emission spectroscopy. The data obtained demonstrate that As contamination in radish tuber is underlined with the dual approach.PRACTICAL APPLICATIONSThe scope of this research is the evaluation of the effects on the toxicology and the morphology because of the arsenic (As) uptake by edible plants. The focus is on the contamination of the plant, which has implications for food safety and human health. The results obtained by magnetic resonance imaging and inductively coupled plasma atomic emission spectroscopy show that several changes of the internal structure occurred and that some parameters can be used as indicators of the As contamination in food.
Journal of Food Quality 06/2010; 33(4):529 - 543. · 0.54 Impact Factor
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ABSTRACT: The methylprednisolone steroid ester of hyaluronan was hydrolyzed under physiological conditions in vitro, and the kinetics of drug release was investigated by NMR spectroscopy. Transverse relaxation times are correlated with the molecular rotational freedom, which undergoes large changes for methylprednisolone when released. Multi-exponential decays were observed, which together with the corresponding population gave valuable insights into the conformational changes that occur in the biopolymer during hydrolysis. The biomaterial exists in aqueous solution in two conformations, 'collapsed' and 'water-exposed', in equilibrium. Under physiological conditions, the methylprednisolone is completely released within 48 h. Transverse relaxation times proved to be an appropriate tool for monitoring the drug release in vitro.
Carbohydrate research 11/2008; 344(2):245-9. · 2.03 Impact Factor
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ABSTRACT: Molecular self-diffusion coefficients (D) of species in solution are related to size and shape and can be used for studying association phenomena. Pulsed field gradient nuclear magnetic resonance (PFG-NMR) spectroscopy has been revealed to be a powerful analytical tool for D measurement in different research fields. The present work briefly illustrates the use of PFG-NMR for assessing the existence of interactions in very different chemical systems: organic and organometallic compounds, colloidal materials and biological aggregates. The application of PFG-NMR is remarkable for understanding the role of anions in homogenous transition metal catalysis and for assessing the aggregation behaviour of biopolymers in material science.
Magnetic Resonance in Chemistry 10/2008; 46 Suppl 1:S16-23. · 1.44 Impact Factor
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ABSTRACT: Consolidation treatment of porous materials was performed by in situ and frontal polymerization of acrylic monomers inside a porous stone. To study the penetration of the polymer inside the stone and its consolidating effects we used water as a contrast agent, detecting its penetration using unilateral NMR and magnetic resonance imaging. All data obtained on differently treated stones were compared with corresponding ones obtained analyzing both untreated stones and stones simply painted with a well-known polymeric protective agent. In situ polymerization of acrylic monomers inside porous stones has been demonstrated to be an extremely powerful consolidating method, whereas thermally initiated frontal polymerization seems less efficient. In both cases the optimal choice of monomers is still open and requires further study. Our data indicate that unilateral NMR represents an inexpensive and simple technique for the non-invasive observation of the water uptake and of the effect of consolidation procedures in porous materials.
The Journal of Physical Chemistry B 12/2006; 110(47):23719-28. · 3.70 Impact Factor
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ABSTRACT: Magnetic resonance imaging (MRI) spectroscopy is a promising non-invasive and non-destructive analytical technique in food science, since it offers the opportunity of studying vegetables and fruits in their wholeness without any manipulation. The aim of this preliminary study was to demonstrate the possibility of assessing unambiguously the place of origin of fresh cherry tomatoes by means of MRI experiments. The innovative approach has been successfully used to distinguish PGI (Protected Geographical Indication) cherry tomatoes from non-PGI ones, as well as cv. Naomi from cv. Shiren samples. The method determines informative physical and morphological parameters, transverse relaxation times and thicknesses, respectively, which can be combined into four empirical equations; two of them are used to determine the cultivated variety and the other two to assess the place of origin. This approach has successfully recognize the cultivated variety of c. 90% of the analyzed samples and the geographical origin of c. 80% of the investigated cherry tomatoes. Copyright © 2006 Society of Chemical Industry
Journal of the Science of Food and Agriculture 10/2006; 87(1):127 - 132. · 1.44 Impact Factor
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ABSTRACT: [Chemical structure: see text] The interactions between a biomaterial and biomolecules present in body fluids often determine the fate of the biomaterial. This paper presents a study on hyaluronan (HA)-containing materials (in soluble or colloidal form) that focuses on their interactions with lipids and proteins and for the first time uses PFG NMR as an analytical technique for probing these events. The interactions of HA-based polymers with phospholipids (DPPC and DPPG liposomes) are shown to depend both on charge and hydrophobicity factors. Despite the difference in behavior between albumin (substantially non-adhesive) and fibrinogen (adhesive), the interactions of the polymers with proteins do not seem to be based on hydrophobic effects but on surface polar interactions.
Macromolecular Bioscience 09/2006; 6(8):611-22. · 3.89 Impact Factor
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ABSTRACT: Magnetic resonance imaging (MRI) spectroscopy is a promising nondestructive analytical technique in food science. It offers the unique opportunity of studying vegetables, fruits and other foods in general, in their wholeness without any preparative manipulation of the sample. The aim of this study was to investigate the internal structure of radish and to monitor the variations induced by postharvest storage at low relative humidity. The MRI allowed for a clear definition of the internal structure of radishes with distinct visibility of xylematic and phloematic vessels distributed in a radial way. A decrease in water content, which results in the breakdown of tissues and the formation of large cavities with the detachment of the external cortex, is the main consequence of a few days' storage in low relative humidity. Both of these are factors that drastically decrease the quality of the radish's fleshy root. The MRI images give a novel insight into the internal organization of the hypocotyl, and this offers opportunities for further studies with regard to the structural differences related to the cultivars as well as the cultivation system.
Journal of Food Quality 11/2005; 28(5‐6):428 - 438. · 0.54 Impact Factor
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ABSTRACT: Vesicles formed in water by synthetic macro-amphiphiles have attracted much attention as nanocontainers having properties that extend the physical and chemical limits of liposomes. We sought to develop ABA block copolymeric amphiphiles that self-assemble into unilamellar vesicles that can be further oxidatively destabilized. We selected poly(ethylene glycol) (PEG) as the hydrophilic A blocks, owing to its resistance to protein adsorption and low toxicity. As hydrophobic B blocks, we selected poly(propylene sulphide) (PPS), owing to its extreme hydrophobicity, its low glass-transition temperature, and most importantly its oxidative conversion from a hydrophobe to a hydrophile, poly(propylene sulphoxide) and ultimately poly(propylene sulphone). This is the first example of the use of oxidative conversions to destabilize such carriers. This new class of oxidation-responsive polymeric vesicles may find applications as nanocontainers in drug delivery, biosensing and biodetection.
Nature Material 04/2004; 3(3):183-9. · 32.84 Impact Factor
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ABSTRACT: We report the application of the pulse gradient spin-echo (PGSE) NMR technique (PGSE NMR) to the analysis of large colloidal materials, specifically vesicles formed from macromolecular amphiphiles and nanoparticles. Measurements of size and size distribution were demonstrated to be comparable to those obtained through dynamic light scattering or hydrodynamic chromatography. In comparison to these more common analytical methods, the use of PGSE NMR is particularly advantageous in that, as a spectroscopic technique, it adds chemical selectivity to the study of physical dimensions. In this way, chemically different species contemporarily present in a sample may be individually studied. In addition, we demonstrate the use of PGSE NMR to probe the existence of equilibria between macroamphiphiles present in solution and those present in vesicles or on the surface of nanoparticles. This feature in particular opens exciting possibilities for the characterization of the phase behavior and of the surface adsorption phenomena of colloids.
Journal of the American Chemical Society 03/2004; 126(7):2142-7. · 9.91 Impact Factor
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ABSTRACT: Methylprednisolone steroid esters of hyaluronan differing in degree of functionalization and molecular weight were investigated in aqueous solution. Conformation and aggregation phenomena were elucidated by means of circular dichroism, viscometry, rheology, and nuclear magnetic resonance, mainly by (1)H pulsed field gradient (PFG) NMR, which allows the determination of the diffusion coefficient of the species under investigation. The functionalization of hyaluronan with the steroid induces a reduction of the molecular volume, as a consequence of intramolecular hydrophobic interactions. For concentrated samples we have observed the coexistence of unimolecular collapsed chains and of aggregates, the latter disappearing upon dilution. The methylprednisolone ester of lower molecular weight hyaluronan has a larger molecular volume than its higher molecular weight analogue, even though still smaller than the underivatized polymer. This effect can be explained with the reduced flexibility of the polymer backbone probably impairing intramolecular interactions.
Biomacromolecules 6(3):1648-53. · 5.48 Impact Factor
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ABSTRACT: We used Magnetic Resonance Imaging spectroscopy to reveal the use of two Plant Growth Regulators (PGRs), i.e. cytokinin and auxin, on Hayward kiwifruits, at any stage of cultivation, and post-harvest ripening and storage. The internal morphology was non-destructively determined in order to depict structural features related to hormones treatments and we found that T2-weighted MRI images showed different internal tissue organisations depending upon the use and the type of PGR. Transverse relaxation times allowed the recognition of cytokinin-treated samples, whilst image analysis was used to identify auxin-treated kiwifruits. We also exploited the post-harvest conditions, i.e. normal refrigeration and controlled atmosphere, on PGRs treated kiwifruits, and found that auxin shortened the shelf-life, with normal refrigeration exerting a stronger effect. The kiwifruit pulp was also investigated by means of Scanning Electron Microscopy, highlighting significant differences at a cellular level amongst treatments, in terms of pore size and vacuoles number, both probably playing a fundamental role in the evaporation activity.Research highlights► Recognition of the use of hormones in organic kiwifruits farming. ► Post-harvest evaluation of kiwifruits treated with synthetic hormones. ► View of the modification of the kiwifruits internal structure as a function of PGR use and type. ► Non destructive assessment of PGR use in kiwifruit at any stage of cultivation, ripening and storage.
Food Chemistry. 126(2):731-736.
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ABSTRACT: Magnetic resonance imaging (MRI) has been used to study the variations of internal structure and chemical–physical characteristics of cherry tomatoes (Lycopersicon esculentum cv. Shiren), one the most economically valuable horticultural crops, in different harvesting seasons. In particular, the study focused on PGI (Protected Geographical Indication) Pachino cherry tomatoes, characterised by taste and nutritional value, notably in the winter production, amounting about 500 ton/year.Spin–spin and spin–lattice relaxation times, T2 and T1 respectively, determined on whole fruit, provided useful data highlighting variations among samples according to the season (winter, spring and summer). MRI images evidenced differences among cellular tissues such as pericarp and endocarp, through variations of: (1) T2 and T1 measures and water tumbling and diffusion motion, (2) thicknesses of different morphological zones, (3) qualitative characteristics of the tissue covering placental cavities where seeds are contained. Results of variance analysis (ANOVA) showed that physical parameters, as the transverse and longitudinal relaxation times, T2 and T1, measured in the morphological tissues of vegetables are excellent variables highlighting their differences in different seasons. This innovative non-destructive technique in food science has great potential in fruit quality assessment.
Food Chemistry.
