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Consulta: creatorFacets:"Soares, Maria Elisa"
Registros recuperados: 12
Data/hora: 09/06/2017 07:12:48
A utilização do cobre na protecção fitossanitária da oliveira e implicações na segurança alimentar dos
produtos do olival.
Provedor de dados: 188
Autores: Pereira, J.A.; Soares, Maria Elisa; Pavão, Francisco; Bastos, Maria de Lurdes; Bento, Albino.
Na protecção fitossanitária da oliveira, especialmente na luta contra doenças fúngicas, são utilizados pesticidas com diferentes
formulações de cobre. A utilização destes produtos e permitida nos diferentes sistemas de protecção do olival, quer seja em
produção convencional, em produção integrada ou no modo de produção biológico, o que os torna de utilização praticamente
generalizada. Neste sentido, o presente trabalho teve por objectivos estudar a persistência do cobre, aplicado sob diferentes formas
- calda bordalesa, hidróxido de cobre e oxicloreto de cobre - em folhas de oliveira e azeitonas durante um período de 44 dias após
a aplicação e no azeite obtido em azeitonas processadas em final desse período.
Tipo: ConferenceObject
Ano: 2009
URL: http://hdl.handle.net/10198/5137
Antioxidant activity and phenolic contents of Olea europaea L. leaves sprayed with different cooper
formulations
Provedor de dados: 188
Autores: Ferreira, Isabel C.F.R.; Barros, Lillian; Soares, Maria Elisa; Bastos, Maria de Lourdes; Pereira, J.A.
The presence of cooper can catalyse oxidation of fatty acid chains, exerting a deleterious influence over shelf life. Transition
metals, which possess two or more valence states with a sui tab le redox potential, act as pro-oxidants even at concentrations
lower than 0.1 ppm, and could affect the speed of autoxidation and the direction of hydroperoxide breakdown to volatile le
compounds. Being copper a transition metal that even, in small concentration, is a very potent oxidation catalyst, can enter a redox
reaction, giving rise to consequent lipid peroxidation phenomenon due to the free radicals producing.
Tipo: ConferenceObject
Ano: 2006
URL: http://hdl.handle.net/10198/3549
Antioxidant activity and phenolic contents of Olea europaea L. leaves sprayed with different copper
formulations
Provedor de dados: 188
Autores: Ferreira, Isabel C.F.R.; Barros, Lillian; Soares, Maria Elisa; Bastos, Maria de Lourdes; Pereira, J.A.
Olive trees (Olea europaea L. Cv. Cobranc¸osa) from the northeast of Portugal were sprayed with three different copper
formulations [bordeaux mixture (copper sulphate + calcium hydroxide - 20% Cu), copper hydroxide (40% Cu) and copper
oxychloride (50% Cu)] to control olive fungal diseases. The residues of copper in olive leaves, harvested at different times, were
evaluated by atomic absorption spectrometry. At all the collection times, treated olive leaves had significantly higher copper
contents, compared to the control. The different copper amounts in pesticide formulations lowered the leaves contents in total
phenols and hence their antioxidant properties. Olive leaves sprayed with copper oxychloride possessed the highest copper levels
and the lowest...
Tipo: Article
Palavras-chave: Olea europaea; Olive leaves; Copper; Phenols; Antioxidant activity.
Ano: 2007
URL: http://hdl.handle.net/10198/749
Copper and lead residues in olives after olive tree treatments with three different copper
formulations.
Provedor de dados: 188
Autores: Soares, Maria Elisa; Pereira, J.A.; Bastos, Maria de Lurdes.
Tipo: ConferenceObject
Ano: 2005
URL: http://hdl.handle.net/10198/5575
Copper residues in olives after olive tree treatments with three different copper formulations.
Provedor de dados: 188
Autores: Soares, Maria Elisa; Pereira, J.A.; Bastos, Maria de Lurdes.
Tipo: ConferenceObject
Ano: 2004
URL: http://hdl.handle.net/10198/5512
Extracção de nutrientes minerais do solo, de povoamentos de Castanea sativa Mill., pela colheita de
cogumelos silvestres comestíveis
Provedor de dados: 188
Autores: Baptista, Paula; Meirinhos, Julieta; Martins, Anabela; Soares, Maria Elisa.
No nordeste de Portugal, na última década tem-se assistido a uma intensificação da colheita e comercialização de cogumelos
silvestres comestíveis. Apesar da grande diversidade de cogumelos existentes, os colectores, apenas procedem à colheita de
algumas espécies, nomeadamente Hydnum rufescens, Boletus edulis, Cantharellus cibarius, Tricholoma acerbum, Xerocomus
chrysenteron e em menor quantidade Clitopilus prunulus. Todos estes cogumelos são micorrizicos de Castanheiro. Com o presente
trabalho pretendeu-se conhecer os teores de macronutrientes (Azoto – amoniacal e nítrico, fósforo e potássio total) e de alguns
micronutrientes (cálcio e magnésio) mobilizados por estes fungos e por conseguinte retirados à cultura de Castanea sativa Mill..
Para tal,...
Tipo: ConferenceObject
Palavras-chave: Cogumelos silvestres comestíveis; Composição mineral; Fungos micorrízicos; Castanea sativa Mill.
Ano: 2004
URL: http://hdl.handle.net/10198/5719
Metal composition of table olives from the portuguese market.
Provedor de dados: 188
Autores: Soares, Maria Elisa; Bento, Albino; Bastos, Maria de Lurdes; Pereira, J.A.
Olive tree (Olea europaea L.) is one of the most important fruit trees in the Mediterranean countries. Their products, olive oil and
also table olives, are important components of the Mediterranean diet and are largely consumed in the world. Table olives are
well-known sources of compounds with important biological properties. The preparation of table olives follows three main trades,
namely green or Spanish-style olives (Green Olives in Brine - GOB), black ripe or Californian-style olives (Black Ripe Olives),
and naturally fermented olives (Direct Brined Olives – DBO). Heavy metals can be present in olive fruits for several reasons:
endogenous, depending on the mineral constitution of the soils where the olive trees are located, or exogenous, resulting...
Tipo: ConferenceObject
Ano: 2007
URL: http://hdl.handle.net/10198/5344
Tolerance and stress response of Macrolepiota procera to nickel
Provedor de dados: 188
Autores: Baptista, Paula; Ferreira, Sílvia; Soares, Maria Elisa; Coelho, Valentim; Bastos, Maria de Lourdes.
Nickel (Ni) is an essential element for many organisms; however, it is very toxic at high concentrations and also depending on the
species. In macrofungi the mechanisms underlying their Ni tolerance are poorly documented. This study examines, for the first
time, the participation of the antioxidative system in Macrolepiota procera exposed to different Ni2+ concentrations and their
relation with Ni tolerance. The effect of the pH on Ni tolerance was also evaluated. The fungus was cultivated on solid medium
with different NiCl2 concentrations (0.05, 0.2, 0.8 mM) at pH 4, 6, and 8, and fungi growth and Ni uptake were determined. The
antioxidative enzymes catalase (CAT) and superoxide dismutase (SOD) and the production of hydrogen peroxide (H2O2) were...
Tipo: Article
Palavras-chave: Macrolepiota procera; Nickel; Stress; Ni2+ tolerance; Ni2+ accumulation; Hydrogen peroxide; Antioxidant
enzymes.
Ano: 2009
URL: http://hdl.handle.net/10198/4473
Tolerance and stress response of the saprobe macrofungi Macrolepiota procera to nickel
Provedor de dados: 188
Autores: Baptista, Paula; Ferreira, Sílvia; Soares, Maria Elisa; Bastos, Maria de Lourdes.
Nickel (Ni) is an essential element for many organisms however it is very toxic at high concentrations and also depending on the
species. In macrofungi the mechanisms underlying their Ni-tolerance are poorly documented. We examined, for the first time, the
participation of the antioxidative system in the Macrolepiota procera exposed to different Ni2+ concentrations and their relation
with Ni-tolerance. The effect of the pH on Ni-tolerance was also evaluated. The fungus was cultivated on solid medium with
different Ni concentrations (0.05, 0.2, 0.8 mM) at pH 4, 6 and 8, and fungi growth and Ni uptake was determined. The
antioxidative enzymes, catalase (CAT) and superoxide dismutase (SOD) and the production of hydrogen peroxide (H2O2) were
evaluated on...
Tipo: ConferenceObject
Palavras-chave: Macrolepiota procera; Nickel; Stress; Ni-tolerance; Ni-accumulation; Hydrogen peroxide; Antioxidant enzymes.
Ano: 2009
URL: http://hdl.handle.net/10198/4488
Validação de uma metodologia por EAA/AE para avaliação dos níveis de crómio total e crómio
hexavalente em cogumelos
Provedor de dados: 188
Autores: Figueiredo, Ana E.; Soares, Maria Elisa; Baptista, Paula; Castro, Marisa; Bastos, Maria de Lourdes.
Os cogumelos têm sido utilizados como bioindicadores da contaminação ambiental provocada por alguns metais pesados, tais
como, o cádmio, cobre, chumbo, crómio, mercúrio e zinco. Vários autores referem que foram observadas grandes concentrações
de metais pesados nestes macromicetes colhidos em zonas muito poluídas, como sejam, a proximidade de estradas com muito
trânsito, zonas industriais onde haja emissão de gases e resíduos, bem como, zonas próximas de fundições e minas.
Tipo: ConferenceObject
Palavras-chave: Cogumelos; Crómio total; Crómio hexavalente; Espectrometria de Absorção Atómica com Atomização
Electrotérmica.
Ano: 2007
URL: http://hdl.handle.net/10198/5937
Validation of a method to quantify copper and other metals in olive fruits by ETAAS. Application to
the residual metal control after olive tree treatments with different copper formulations
Provedor de dados: 188
Autores: Soares, Maria Elisa; Pereira, J.A.; Bastos, Maria de Lourdes.
An electrothermal atomization atomic absorption spectrometry method was validated to quantify residues of copper, aluminum,
cadmium, chromium, iron, lead, and nickel in olive fruit. The linearity ranges under the optimized conditions were 0.19-20.0,
1.11-50.0, 0.02-2.0, 0.15-20.0, 0.80- 20.0, 0.35-50.0, and 0.60-50.0 íg/L, respectively. The limits of quantification were, expressed
in nanograms per gram of dry weight, 12.6, 74.0, 1.34, 10.0, 53.4, 23.4, and 40.0, respectively. For all of the metals the precision
of the instrumental method was <6.3% and that of the analytical method was always <10%, except for aluminum, for which
the precision was 12%. The accuracy of the method was evaluated according to the standard additions method, the recoveries...
Tipo: Article
Palavras-chave: Method validation; Atomic absorption spectrometry; Metal residues; Olive fruit; Fungicide residues.
Ano: 2006
URL: http://hdl.handle.net/10198/748
Validation of an electrothermal atomization atomic absorption spectrometry method for
quantification of total Chromium and Chromium(VI) in wild mushrooms and underlying soils
Provedor de dados: 188
Autores: Figueiredo, Ana E.; Soares, Maria Elisa; Baptista, Paula; Castro, Marisa; Bastos, Maria de Lourdes.
An ETAAS method was validated to quantify total Cr and CrVI in mushrooms and the underlying soils. The method includes a
sample pretreatment for total Cr dissolution using a wet acid digestion procedure and a selective alkaline extraction for CrVI. The
limits of detection were, expressed in íg/L, 0.15 and 0.17 for total Cr and CrVI, respectively. The linearity ranges under the
optimized conditions were 0.15-25.0 and 0.17-20.0 íg/L for total Cr and CrVI, respectively. The limits of quantification were,
expressed in íg/g of dry weight, 0.0163 and 0.0085 for total and hexavalent chromium, respectively. The precision of the
instrumental method for total Cr and CrVI was lower than 1.6%, and for the analytical method, it was lower than 10%. The
accuracy of the...
Tipo: Article
Palavras-chave: Mushrooms; Soil; Total Cr; CrVI; Atomic absorption spectrometry.
Ano: 2007
URL: http://hdl.handle.net/10198/942