Salgado, Maria Antónia; Fernandes, Conceição; Teixeira, C.; Cortez, A.
Fernandes, Conceição; Fontaínhas-Fernandes, A.; Carrola, J.S.; Salgado, Maria Antónia
Gomes, Teresa; Barradas, Carla; Dias, Teresa; Andrade, João Verdial; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.
Mead production represents a possible economic alternative to honey producers that intend to obtain honey products with surplus value. From that the present work aims to study the influence of using different production scales on the quality of the final mead obtained and on the process performance. Increasing the production scale almost ten times (1.5 to 20 L), some differences were observed. Maximum specific growth rates equal to 0.045 and 0.038 h-1 were obtained for fermentations carried out at 1.5 and 20 L, respectively. The time course of glucose and glycerol were similar for both production scales. Nevertheless, slight differences...
Afonso, Sílvia Marlene Esteves; Oliveira, Ivo; Ramalhosa, Elsa; Asensio-S.-Manzanera, M. Carmen; Asensio, Carmen; Bento, Albino; Pereira, J.A.
O feijão (Phaseolus ltztlgaris L.) é uma leguminosa largamente consumida no mundo, estando-lhe associadas diferentes propriedades nutricionais. Nas últimas décadas o Instituto Tecnológico Agrário de Castela e Leão (ITACyL) tem-se dedicado ao desenvolvimento de novas variedades de feijão. Neste sentido, com o presente trabalho procedeu-se à avaliação do teor em fenóis totais, e da actividade antioxidante através do efeito bloqueador dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo) em dez variedades de feijão desenvolvidas naquele organismo (Almonga, Cárdeno, Cardina, Casasola, Corcal, Curruquilla, Moradillo, Tafioga, Tremaya e Tropical). O teor em fenóis totais foi muito diferente entre variedades oscilando entre 4.19±0.18 (variedade Almonga)...
Estimates of soil water retention characteristics using pedotransfer functions (PTFs) are useful in many studies, such as hydrological modelling and soil
mapping. Also reliable information about soil hydraulic properties like water retention characteristic and conductivity functions often constitutes an essential
precondition to adequately apply protection and remediation techniques to soil related problems in forest ecology.
The determination of the parameters for these functions can be obtained from direct laboratory and field measurements. However, these measurements are
time consuming which makes it costly to characterize an extensive area of a land. As an alternative, the existing databases of measured soil hydraulic data
may be used to...
Ribeiro, A.C.; Sá, A.; Andrade, João Verdial
Na Região Demarcada do Douro, e em particular na sub-região do Douro Superior, a vinha é conduzida, durante uma parte significativa do seu ciclo
vegetativo, em condições de défice hídrico acentuado associadas a altas temperaturas, elevado stresse radiativo e elevado défice de pressão de vapor. As
práticas culturais implementadas para minimizar as condições adversas, e em particular o regime de rega, podem alterar substancialmente a fisiologia da
videira afectando a produção e a composição do bago.
O principal objectivo deste estudo foi o de avaliar o curso da maturação na variedade Tinta Roriz de Vitis vinífera L., através da monitorização dos principais
parâmetros da maturação,...
Ribeiro, A.C.; Andrade, João Verdial
The behaviour of cv. “Tinta Roriz” (Vitis vinifera L.), was studied when moderate drip irrigation was applied from veraison to harvest. Field studies were conducted during three growing seasons (2006-2008) in a commercial vineyard located in the Douro region, Portugal. Experimental layout consisted in the measurement of physiological and agronomic parameters in vines submitted to three different irrigation treatments: 0R was non-irrigation, 2R and 4R were irrigated with a constant fraction of reference evapotranspiration of 0.2 and 0.4, respectively. The results showed that moderate irrigation improved plant water status, leaf photosynthesis and transpiration. Yield components and pruning weights had a...
Martins, Vitor Manuel Ramalheira; Coimbra, Manuel A.
The use of plant infusions with medicinal purposes, such as the ones from members of the Fraxinus genus, is an ancient practice that has been reported by popular medicine . The health benefits are associated with the presence of phenolic compounds and polysaccharides, among others . Although phenolic compounds have been studied in detail for more than two decades, the characterization of the polysaccharides present in plant infusions and their involvement in the health benefits is still incipient.
The polysaccharides of F. angustifolia dried leaves were recovered by dialysis (12-14 kDa cut-off). The high molecular weight material comprised approximately 2% of...
Martins, Vitor Manuel Ramalheira; Coimbra, Manuel A.
The use of plant infusions for medicinal purposes is present in secular traditions of all civilizations. In Portugal, in Trás-os-Montes region, the small shrub (Pterospartum tridentatum), the narrow-leafed ash (Fraxinus angustifolia), and the apple mint (Mentha suaveolens) are plants used for such purposes. According to the popular tradition, the infusions of P. Tridentatum, F. Angustifolia, and M. suaveolens protect against diabetes, high blood pressure, high levels of cholesterol, and uric acid .These health benefits are associated with the presence of phenolic compounds, essential oils, and polysaccharides, among others. Although phenolic compounds and essential oils have been studied in detail for...
Martins, Vitor Manuel Ramalheira; Coimbra, Manuel A.
In the Trás-os-Montes region, the use of infusions of Fraxinus angustifolia dried leaves as a protection against high levels of cholesterol, blood pressure and uric acid is widespread. Pectic polysaccharides isolated from the infusions of some medicinal plants have been reported as biologically active [1,2]. Pectic poly-saccharides have been described as structurally complex polymers, exhibiting different polymeric building blocks: homogalacturonans (HG), rhamnogalacturonans-I (RG-I), rhamnogalacturonans-II (RG-II) and xylogalacturonans (XG) . The backbone of RG-I can be partly substituted with various side chains, such as arabinans, type-I and type-II arabinogalactans (AG-I and AG-II). The aim of this work is to provide a...
Ribeiro, A.C.; Melo-Abreu, J. Paulo de
O fluxo de calor no solo é um dos componentes do balanço de energia à superfície do solo. A sua medição é fundamental em várias aplicações
micrometeorológicas que requerem a quantificação dos componentes do balanço energético como por exemplo a determinação da taxa de
evaporação do solo, da taxa de arrefecimento nocturno, entre outras.
A determinação do fluxo de calor no solo pode ser efectuada através de métodos que se baseiam na medição da temperatura do solo, utilizando
placas de fluxo de calor ou através da combinação dos dois métodos. Além da precisão, a simplicidade e o custo são factores determinantes na
selecção do método...
Melo-Abreu, J. Paulo de; Ribeiro, A.C.; Snyder, R.L.
Good quality apples are grown in relatively cold areas. However, frost frequently causes damage to flowers and small fruits. When the percentage of frost damage losses is higher than the
thinning requirement of the cultivar, production is reduced. In addition to reducing yield, frost damage to the skin and malformation of the fruits often devalues the quality and reduces
Critical temperature tables in relation to phenological stage are available for apples and other deciduous crops (Ballard and Proebsting, 1978; Proebsting and Mills, 1978). Some of the
data came from field observations using temperatures from standard shelters and some came from excised branch chamber...
Ribeiro, A.C.; Melo-Abreu, J. Paulo de; Gonçalves, D.A.
A geada em Portugal e particularmente nas regiões do interior norte e centro
provoca, frequentemente, danos em fruteiras caducifólias importantes como a
macieira, cerejeira e amendoeira. O rendimento dos agricultores é severamente
afectado e a não estabilização das produções tem igualmente consequências ao
nível das empresas e cooperativas do sector. Além da redução da produção, a
geada provoca deformações e outros defeitos nos frutos, diminuindo
consequentemente o seu valor comercial.
A minimização de potenciais prejuízos pode fazer-se através da
implementação de medidas preventivas (protecção passiva) e actuando
imediatamente antes ou durante a noite de geada (protecção activa) (Snyder &
de Melo-Abreu, 2005). Nos métodos indirectos ou passivos – de carácter
Cardoso, Susana M.; Falcão, Soraia; Peres, António M.; Pereira, Olívia R.; Domingues, M.R.M.
Olive mill wastewater (OMW), the effluents generated in the olive oil extraction
industry operating in three-phases mode, are phytotoxic mainly due to its high
phenolic content . On the other hand, attending to the potential healthbenefits
of some of their phenolic compounds, OMW are now regarded as a
potent source of biophenols for food and pharmaceutical industries. An
important portion of the OMW biophenols include the secoiridoids found in
olive pulp and their derivatives formed along the olive oil extraction process
. Still, due to the complex composition of OMW, many phenolic compounds
remain unknown. Their structural identification can encourage the search of
new bioactive compounds in OMW and...
Peres, António M.; Dias, L.G.; Veloso, Ana C.A.; Sousa, Mara E.B.C.; Machado, A.A.S.C.
Aires, A.; Carvalho, R.; Fernandes, Conceição; Saavedra, M.J.; Rosa, E.
Machado, Carla; Fernandes, Conceição; Pereira, Joel; Poças, Maria de Fátima
The present work presents an exercise to simulate exposure of Portuguese consumers to
benzophenone, a photoinitiator used in packaging printing inks. The simulation model combined
experimental data of benzophenone concentration found in packages collected from market and
food consumption and packaging usage data obtained from a database. The model followed a
probabilistic approach: the distribution of occurrence data was combined with food consumption
data in a probabilistic simulation with the Monte Carlo sampling method. The values found
indicate that benzophenone levels of exposure are of no health concern according to the tolerable
daily intake defined by EFSA.
Nobre, Clarisse; Santos, M.J.; Dominguez, Ana; Torres, Duarte; Peres, António M.; Rocha, Isabel; Ferreira, Eugénio C.; Rodrigues, Lígia R.; Teixeira, José A.
Separation of glucose from mixtures of fructose and sucrose in molasses is a major challenge in industrial sugar
chromatographic separations. The efficiency of a chromatographic process is largely dependent on the adsorbent
used. Sulfonated poly(styrene-co-divinylbenzene) (PS-DVB) ion exchange resins are the most frequently used
for sugars separation, generally in a cationic form. The cation will complex with the hydroxyl group of the sugar
leading to a selective adsorption according to the orientation of the hydroxyl group. Thus, the conformation of
the sugar determines its relative affinity for the resin and its distribution coefficient. Consequently, fructose
forms the more stable sugar-cation complex being preferentially adsorbed in the...
Nobre, Clarisse; Vaňková, K.; Peres, António M.; Polakovič, M.; Teixeira, José A.; Rodrigues, Lígia R.
Fructo-oligosaccharides (FOS) namely, kestose, nystose and
fructofuranosylnystose, are prebiotics that can be obtained by fermentation. The
resulting fermentative broth is a complex mixture consisting also of salts and
other sugars that must be removed. Adsorption equilibrium studies were
conducted using the static method in batch mode onto Dowex Monosphere
calcium resin, at 60ºC, for FOS contained in a fermentative broth and pure
mixtures. Experimental isotherms data were analyzed using linear,
Langmuir/anti-Langmuir, Freundlich, Redlich & Peterson, and Toth models.
Isotherm parameters were determined using linear and nonlinear correlations
for the minimization of several error functions. The nonlinear correlations were
found to provide the best isotherm parameters for the models. FOS contained...
Cardoso, Susana M.; Falcão, Soraia; Peres, António M.; Domingues, M.R.M.
Olive mill wastewaters (OMW) have been attracting the attention of food and
pharmaceutical industries, as it is a potential source of biophenols with a wide
range of biological activities. This effluent produced in the olive oil industry
contains approximately half of the total phenolic compounds of the olive fruit and
it is currently exploited for industrial extraction of hydroxytyrosol . Still, the
phenolic composition of OMW is extremely complex, and many compounds are
yet unidentified. In this context, the identification of unknown phenolic
compounds can encourage the search of new bioactive compounds in OMW and
contribute to further valorize this waste.
In the present work, six new phenolic compounds...