9 documents found, page 1 of 1
A simple ultraperformance liquid chromatography mass spectrometry method for th...
Oliveira, Carla M.; Campos, Inês; Vidigal, Susana S. M. P.; Pintado, Manuela E.; Oliveira, Catarina S. S.A simple, precise, and rapid ultra-performance liquid chromatography method for cortisol quantification in sea bass plasma, based on LC-ESI-UHR-QqTOF-MS, was optimised using tolperisone as internal standard. Sea bass plasma samples containing cortisol were spiked with tolperisone as internal standard and extracted with acetonitrile. Samples were vortexed and centrifuged at 15,000g for 10 min at 4 °C. The final ...
Quantification of 3-deoxyglucosone (3DG) as an aging marker in natural and forc...
Oliveira, Carla M.; Santos, Sónia A. O.; Silvestre, Armando J. D.; Barros, António S.; Ferreira, António César S.; Silva, Artur M. S.The Maillard reaction product 3-deoxyglucosone (3DG) was quantified in wines, by high-performance liquid chromatography-mass spectrometry analysis after derivatization with ortho-phenylenediamine. Both sweet red Port wines and dry white wines were analysed during natural and forced aging. In natural aging, and for dry white wines, 3DG is negatively correlated to age (r = −0.939), while for sweet red Port wines,...
Estatística espacial aplicada aos estudos de incidência de câncer
Friestino, Jane Kelly Oliveira; Mendonça, Denisa; Oliveira, Pedro; Oliveira, Carla M.; Ferraz, Rosemeire de Olanda; Filho, Djalma de Carvalho MoreiraO Sistema de Informação Geográfica (SIG) como ferramenta em estudos epidemiológicos tem se tornado algo frequente na área da Saúde Coletiva. Em estudos sobre incidência de câncer, o uso da análise espacial ainda é incipiente no país, entretanto possuí grande potencial para auxílio nos modelos de planejamento em saúde. O objetivo deste trabalho é apresentar um método empírico de análise de padrões espaciais para...
Quantification of 3-deoxyglucosone (3DG) as an aging marker in natural and forc...
Oliveira, Carla M.; Santos, Sonia A. O.; Silvestre, Armando J. D.; Barros, Antonio S.; Ferreira, Antonio C. S.; Silva, Artur M. S.The Maillard reaction product 3-deoxyglucosone (3DG) was quantified in wines, by high-performance liquid chromatography-mass spectrometry analysis after derivatization with ortho-phenylenediamine. Both sweet red Port wines and dry white wines were analysed during natural and forced aging. In natural aging, and for dry white wines, 3DG is negatively correlated to age (r=0.939), while for sweet red Port wines, 3D...
Saccharomyces cerevisiae oxidative response evaluation by cyclic voltammetry an...
Castro, Cristiana C.; Gunning, Caitriona; Oliveira, Carla M.; Couto, José A.; Teixeira, José A.; Martins, Rui C.; Ferreira, António C. SilvaThis study is focused on the evaluation of the impact of Saccharomyces cerevisiae metabolism in the profile of compounds with antioxidant capacity in a synthetic wine during fermentation. A bioanalytical pipeline, which allows for biological systems fingerprinting and sample classification by combining electrochemical features with biochemical background, is proposed. To achieve this objective, alcoholic fermen...
Saccharomyces cerevisiae oxidative response evaluation by cyclic voltammetry an...
Castro, Cristiana C.; Gunning, Caitriona; Oliveira, Carla M.; Couto, José A.; Teixeira, J. A.; Martins, Rui C.; Ferreira, António C. SilvaThis study is focused on the evaluation of the impact of Saccharomyces cerevisiae metabolism in the profile of compounds with antioxidant capacity in a synthetic wine during fermentation. A bioanalytical pipeline, which allows for biological systems fingerprinting and sample classification by combining electrochemical features with biochemical background, is proposed. To achieve this objective, alcoholic fermen...
Oxidation management of white wines using cyclic voltammetry and multivariate p...
Martins, Rui C.; Oliveira, Raquel; Bento, Fatima; Geraldo, Dulce; Lopes, Vitor V.; Pinho, Paula Guedes de; Oliveira, Carla M.The development of a fingerprinting strategy capable to evaluate the “oxidation status” of white wines based on cyclic voltammetry is proposed here. It is known that the levels of specific antioxidants and redox mechanisms may be evaluated by cyclic voltammetry. This electrochemical technique was applied on two sets of samples. One group was composed of normal aged white wines and a second group obtained from a...
New qualitative approach in the characterization of antioxidants in white Wines...
Oliveira, Carla M.; Ferreira, António C. S.; Pinho, Paula Guedes de; Silva, Artur M. S.The aim of this study was to obtain new information on antioxidant compounds in white wines. For this purpose, white wine degradation was promoted by a forced aged protocol, and six normally aged white wines from different vintages were analyzed. Both normal and forced aged wines were sequentially extracted using hexane and ethyl acetate. Apolar antioxidants were removed using hexane, and polar antioxidants wer...
Development of a potentiometric method To measure the resistance to oxidation o...
Oliveira, Carla M.; Ferreira, António C. Silva; Pinho, Paula Guedes de; Hogg, TimThis work describes a new potentiometric method to evaluate the resistance to oxidation of white wines. Reduction and oxidation titrations were made, and coefficient of variation obtained were 10.87 and 2.65%, respectively. The antioxidant powers of ascorbic acid (Aas) and sulfur dioxide (SO2) were evaluated by this method, SO2 proving to be much less active in this respect than ascorbic acid. The two agents di...