Encontrados 10 documentos, a visualizar página 1 de 1
Suberin of Potato (Solanum tuberosum Var. Nikola): Comparison of the Effect of ...
Jarvinen, Riikka; Silvestre, Armando J. D.; Holopainen, Ulla; Kaimainen, Mika; Nyyssola, Antti; Gil, Ana M.; Neto, Carlos Pascoal; Lehtinen, PekkaChemical and enzymatic depolymerizations of suberin isolated from potato peel (Solanum tuberosum var. Nikola) were performed under various conditions. Enzymatic hydrolysis with cutinase CcCut1 and chemical methanolysis with NaOMe of suberin yielded monomeric fragments, which were identified as TMS derivatives with GC-MS and GC-FID. The solid, hydrolysis-resistant residues were analyzed with solid state (13)C CP...
Evaluation of beer deterioration by gas chromatography–mass spectrometry/multiv...
Rodrigues, João A.; Barros, António S.; Carvalho, Beatriz; Brandão, Tiago; Gil, Ana M.; Ferreira, António C. SilvaBeer stability is a major concern for the brewing industry, as beer characteristics may be subject to significant changes during storage. This paper describes a novel non-targeted methodology for monitoring the chemical changes occurring in a lager beer exposed to accelerated aging (induced by thermal treatment: 18 days at 45 ◦C), using gas chromatography–mass spectrometry in tandem with multivariate analysis (...
NMR metabolomics of esca disease-affected vitis vinifera cv. Alvarinho leaves
Lima, Marta; Felgueiras, Mafalda; Graça, Gonçalo; Rodrigues, João; Barros, António; Gil, Ana M.; Dias, Alberto Carlos PiresEsca is a destructive disease that affects vineyards leading to important losses in wine production. Information about the response of Vitis vinifera plants to this disease is scarce, particularly concerning changes in plant metabolism. In order to study the metabolic changes in Vitis plants affected by esca, leaves from both infected and non-affected cordons of V. vinifera cv. Alvarinho (collected in the Vinho...
Analytical Approaches toward Successful Human Cell Metabolome Studies by NMR Sp...
Duarte, Iola F.; Marques, Joana; Ladeirinha, Ana F.; Rocha, Cláudia; Lamego, Inês; Calheiros, Rita; Silva, Tânia M.; Marques, M. Paula M.The aim of this work was to investigate the effects of cell handling and storage on cell integrity and 1H high resolution magic angle spinning (HRMAS) NMR spectra. Three different cell types have been considered (lung tumoral, amniocytes, and MG-63 osteosarcoma cells) in order for sample-dependent effects to be identified. Cell integrity of fresh cells and cells frozen in cryopreservative solution was 70−80%, w...
Metabolite Profiling of Human Amniotic Fluid by Hyphenated Nuclear Magnetic Res...
Graça, Gonçalo; Duarte, Iola F.; Goodfellow, Brian J.; Carreira, Isabel M.; Couceiro, Ana Bela; Domingues, Maria do Rosário; Spraul, ManfredThe metabolic profiling of human amniotic fluid (HAF) is of potential interest for the diagnosis of disorders in the mother or the fetus. In order to build a comprehensive metabolite database for HAF, hyphenated NMR has been used, for the first time, for systematic HAF profiling. Experiments were carried out using reverse-phase (RP) and ion-exchange liquid chromatography (LC), in order to detect less and more p...
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR ...
Garcia, Helga; Barros, António; Gonçalves, Catarina; Gama, F. M.; Gil, Ana M.Fourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, t...
Metabolic characterisation of plasma in juveniles with glycogen storage disease...
Duarte, Iola F.; Goodfellow, Brian J.; Barros, António; Jones, John G.; Barosa, Cristina; Diogo, Luisa; Garcia, Paula; Gil, Ana M.This paper reports the first application of high-resolution 1H NMR spectroscopy to the plasma of five juveniles with glycogen storage disease type 1a (GSD1a), permitting the characterisation of the plasma metabolic profile and the identification of alterations relative to a set of control samples. The relaxation-weighted spectra allowed changes in low molecular weight compounds to be detected more clearly, wher...
In Situ Synthesis of Magnetite Nanoparticles in Carrageenan Gels
Daniel-da-Silva, Ana L.; Trindade, T.; Goodfellow, Brian J.; Costa, Benilde F. O.; Correia, Rui N.; Gil, Ana M.Magnetite nanoparticles have been successfully synthesized in the presence of carrageenan polysaccharides using an in situ coprecipitation method. Iron coordination to the sulfate groups of the polysaccharide was confirmed by FTIR. The polysaccharide type (κ, ι, or λ) and concentration have been varied and their effects on particle morphology and chemical stability of the resultant nanocomposite investigated. T...
In situ synthesis of magnetite nanoparticles in carrageenan gels
Daniel-da-Silva, Ana. L.; Trindade, T.; Goodfellow, Brian J.; Costa, Benilde F. O.; Correia, Rui N.; Gil, Ana M.Magnetite nanoparticles have been successfully synthesized in the presence of carrageenan polysaccharides using an in situ coprecipitation method. Iron coordination to the sulfate groups of the polysaccharide was confirmed by FTIR. The polysaccharide type ( , é, or ì) and concentration have been varied and their effects on particle morphology and chemical stability of the resultant nanocomposite investigated. T...
Production and characterization of a new dextrin based hydrogel
Carvalho, Joana; Gonçalves, Catarina; Gil, Ana M.; Gama, F. M.Dextrin is a polymer composed of α-(1→4) D-glucose units produced by partial hydrolysis of starch. In this work, the transesterification of the soluble polysaccharide with vinyl acrylate (VA) was carried out in anhydrous dimethylsulfoxide (DMSO). The effect of the water activity and of the enzyme Proleather, on the reaction rates, was analysed. Different degrees of substitution (DS) ranging from ca. 10% to 70% ...
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