836 research outputs found
Chemistry of volcanic soils used for agriculture in Brava Island (Cape Verde) envisaging a sustainable management
In order to acquire a better knowledge of iron forms, clay minerals and the content and distribution of trace elements in soils mostly used for agriculture in the semi-arid Brava Island (Cape Verde), iron speciation, mineralogy and chemical contents in the clay-size fraction (<2 μm) of incipient soils developed on sediments and phonolitic pyroclasts was performed by Mössbauer spectroscopy, X-ray diffraction and neutron activation analysis. In contrast with the whole samples in the clay-size fraction of all the studied soils only Fe(III) was detected. Iron and chromium are depleted suggesting their occurrence as ferromagnesian and oxide minerals present in coarser particles. Rare earth elements are concentrated in the clay-size fraction, and significant differences are found in their distribution which may be partially due to oxidation, since Ce anomalies were observed. Among the other chemical elements studied, high concentrations of arsenic, bromine, and particularly antimony were found in the clay-size fraction of soils where all the Fe oxides are nano-sized, confirming the predominant adsorption of these elements on the nano-particles surface. The existence of significant amounts of these elements as well as of vitreous phases in fine particles of these soils may contribute to their mobility and accumulation in groundwater and in plants, both by absorption and by dust deposition onto the plant leaves.publishe
Tarragon extract as a functional ingredient for development of new pizza dough
Plants are used in various fields due their sensory, nutritional and medicinal properties, and
aromatic plants can be used as functional food ingredients to enhance organoleptic properties
and/or to replace the salt. Additionally, their large amount of bioactive compounds, namely
phenolic compounds (PC), can contribute to food preservation, promote human health (Costa
et al., 2015), and provide bioactive effects. Tarragon, Artemisia dracunculus L., usually known
for its pleasant spicy aroma, is widely used in food preparations (Hassanzadeh et al., 2016). In
this work, a lyophilized hydroethanolic tarragon extract was characterized in terms of PC and
bioactive properties, such as antioxidant, antimicrobial and cytotoxic activities and further used
to develop functional foods namely by its incorporation in pizza dough.POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020
and FCT; Project NORTE-01-0145-FEDER-000006, funded by NORTE2020 under the PT2020,
through ERDF; FCT and ERDF under PT2020 for financial support to CIMO
(UID/AGR/00690/2013). Andreia Ribeiro acknowledges her PhD fellowship funded by Project
NORTE-08-5369-FSE-000028, supported by N2020, under PT2020, through ESF.info:eu-repo/semantics/publishedVersio
Tarragon extract as a functional ingredient for development of new pizza dough
Plants are used in various fields due their sensory, nutritional and medicinal properties, and
aromatic plants can be used as functional food ingredients to enhance organoleptic properties
and/or to replace the salt. Additionally, their large amount of bioactive compounds, namely
phenolic compounds (PC), can contribute to food preservation, promote human health (Costa
et al., 2015), and provide bioactive effects. Tarragon, Artemisia dracunculus L., usually known
for its pleasant spicy aroma, is widely used in food preparations (Hassanzadeh et al., 2016). In
this work, a lyophilized hydroethanolic tarragon extract was characterized in terms of PC and
bioactive properties, such as antioxidant, antimicrobial and cytotoxic activities and further used
to develop functional foods namely by its incorporation in pizza dough.POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020
and FCT; Project NORTE-01-0145-FEDER-000006, funded by NORTE2020 under the PT2020,
through ERDF; FCT and ERDF under PT2020 for financial support to CIMO
(UID/AGR/00690/2013). Andreia Ribeiro acknowledges her PhD fellowship funded by Project
NORTE-08-5369-FSE-000028, supported by N2020, under PT2020, through ESF.info:eu-repo/semantics/publishedVersio
Microalgae-derived pigments: a 10-year bibliometric review and industry and market trend analysis
Microalgae productive chains are gaining importance as sustainable alternatives to obtain natural pigments. This work presents a review on the most promising pigments and microalgal sources by gathering trends from a 10 year bibliometric survey, a patents search, and an industrial and market analysis built from available market reports, projects and companies’ webpages. The performed analysis pointed out chlorophylls, phycocyanin, astaxanthin, and β-carotene as the most relevant pigments, and Chlorella vulgaris, Spirulina platensis, Haematococcus pluvialis, and Dunaliella salina, respectively, as the most studied sources. Haematococcus is referred in the highest number of patents, corroborating a high technological interest in this microalga. The biorefinery concept, investment in projects and companies related to microalgae cultivation and/or pigment extraction is increasingly growing, particularly, for phycocyanin from Spirulina platensis. These pieces of evidence are a step forward to consolidate the microalgal pigments market, which is expected to grow in the coming years, increasing the prospects of replacing synthetic pigments by natural counterparts.CIMO (UIDB/00690/2020) and LA LSRE-LCM (UIDB/50020/2020) base funding by national funds through FCT/MCTES (PIDDAC). AIProcMat@N2020 Ref. NORTE-01-0145-FEDER-000006, supported by NORTE 2020 under the Portugal 2020 partnership agreement, through ERDF fund. National funding by FCT through the individual research grant SFRH/BD/148281/2019 (Samara C. Silva).info:eu-repo/semantics/publishedVersio
In vitro dissolution study in predicting oral absorption of drugs containing paracetamol using an electronic tongue
The bioavailability of drugs is essential for the therapeutic efficacy of medicines, and it is therefore essential to conduct dissolution studies of drugs. The electronic tongue has been demonstrating potential usefulness in this area. Objectives: Verify the potential of electronic tongue in the analysis of paracetamol in different drugs; verify the ability to cross-sensitivity sensors in dissolution studies; selecting a lipidic polymer membrane electrode with good performance in monitoring of samples dissolution.
Methods: Four samples of medicines containing 500mg of Paracetamol: unbranded uncoated pill, branded uncoated pill, unbranded coated pill and branded coated pill have been used. We used a dissolution medium simulating the gastric fasting conditions. The polymer membranes were formed by mixing: 4 lipidic additives, 5 plasticizers and polymer polyvinyl chloride. After stabilization of the potential signals from all electrodes, each sample was placed in a metal tube in contact with the dissolution medium. The experiment ended when the tablet was fully dissolved. The assays were repeated three times for each sample.
Results: Yielded consistent dissolution profiles between repetitions of the same sample for some 40 tested sensors, including the 34 sensor which showed a similar behavior for both formulations. The uncoated pills obtained a dissolution profile of quick release (30’-unbranded; 25’-branded). The lengthy dissolutions resulted in different dissolution profiles between repetitions of the same sample of coated pills and capsules.
Conclusions: The dissolution profile of drugs containing acetaminophen was followed through 40 potentiometric sensors having cross-sensitivity is selected sensor 34, which allow obtaining reproducible results.info:eu-repo/semantics/publishedVersio
Application of a potentiometric electronic tongue for assessing phenolic and volatile profiles of Arbequina extra virgin olive oils
The capability of determining the phenolic and volatile profiles of olive oils is of major relevance since these
compounds are known to greatly influence the gustatory and olfactory positive attributes of olive oils. An
electronic tongue with multiple linear regression models was used to evaluate both profiles based on olive oils
potentiometric data generated during a single assay. The proposed electronic tongue-chemometric procedure
enabled the quantification of flavonoids, phenolic acids and phenol alcohols of Arbequina extra-virgin olive oils
with a similar accuracy of UPLC-MS (0.93 ± 0.03≤R2≤0.98 ± 0.08 for the repeated K-fold cross-validation
procedure). Also, it was verified that the potentiometric device should not be applied to evaluate volatile
compounds in solution (0.80 ± 0.14≤R2≤0.94 ± 0.05 for the repeated K-fold cross-validation procedure),
showing a lower accuracy than HS-SPME-GS-MS. The overall satisfactory results showed that electronic tongue
could be used as a practical sensing instrument to generate a chemical profile of the compounds known to
influence the positive sensory attributes of olive oils.The authors would like to thank Consejo Regulador de
Denominación de Origen (DOP) Estepa and DOP Les Garrigues; Casas
Hualdo, Castillo Canena, Cortijo de Jara, Quaryat Dilar, EPAMIG and
Olivas do Sul for the donation of samples. We would like to dedicate
this work to the memory of Carmen Cabrera-Vique. We are grateful to
the CAPES Foundation, (Ministry of Education, Brazil), for scholarship
support provided to Thays Helena Borges (grant number 6073/13-1),
being presently a Ph.D. student from the Official Doctoral Program
‘‘Nutrition and Food Sciences” of the Granada University. This work
was also financially supported by Project POCI-01–0145-FEDER-
006984–Associate Laboratory LSRE-LCM, strategic project PEst-OE/
AGR/UI0690/2014 –CIMO all funded by FEDER - Fundo Europeu de
Desenvolvimento Regional through COMPETE2020-Programa
Operacional Competitividade e Internacionalização (POCI) – and by
national funds through FCT - Fundação para a Ciência e a Tecnologia,
Portugal.info:eu-repo/semantics/publishedVersio
Bioactivity and phenolic characterization of different medicinal and aromatic plants
Introduction: Plants are widely used to treat various diseases and have been widely recognized as a
rich source of phytochemicals with antimicrobial potential. In fact, plants have received considerable
attention by researchers being their biological properties widely explored.
Hypothesis and aims: Medicinal and aromatic plants are known to have a wide range of uses and
health benefits, and should be exploited concerning their bioactivity. Therefore, the antimicrobial
activity of Satureja montana L., Origanum majorana L., Allium schoenoprasum L. and Anethum
graveolens L. were evaluated and its phytochemical composition was profiled.
Methodology: The antimicrobial susceptibility of Gram-positive and Gram-negative bacteria to four
decoction and hydroethanolic (80:20, v/v) extracts, obtained from medicinal and aromatic plants (S.
montana , O. majorana , A. schoenoprasum and A. graveolens ), was assessed aiming to identify the
active extracts and the most effective were then tested against biofilms. Furthermore, the decoctions
were characterized in terms of phenolic compounds by HPLC-DAD-ESI/MSn.
Results: Overall, S. montana and O. majorana extracts were the most effective against Gram-positive
(Staphylococcus aureus , Enterococcus faecalis and Streptococcus dysgalactiae ) and Gram-negative
(Klebsiella pneumonia and Pseudomonas aeruginosa ) bacteria, with decoction presenting the most
pronounced effects. O. majorana and S. montana decoction, at minimum inhibitory concentrations,
were significantly effective against planktonic cells of S. aureus ATCC 25923. Concerning biofilm cells,
S. montana promoted a slight antimicrobial activity against S. aureus ATCC 25923. A total of twentyfour
phenolic compounds (9 phenolic acids and 15 flavonoids glycosides) were identified in S. montana
and O. majorana decoctions, being rosmarinic acid the main molecule in the extracts.
Conclusion: This study confirmed the bioactive potential of the medicinal and aromatic herbs, being
S. montana and O. majorana decoction extracts those that showed the most promising applicability for
the development of novel formulations with antimicrobial properties.info:eu-repo/semantics/publishedVersio
Datación del recinto murado calcolítico de Las Mesas (La Fuente, España)
El yacimiento amurallado de media hectárea de Las Mesas se ubica en la margen oeste del río Guadiana (La Fuente, Badajoz, España). El análisis de la cultura material recuperada en prospecciones de superficie remite a un arco cronológico que va desde el Neolítico Final (ca. 3600-2900 AC) a la Edad del Cobre (III milenio AC).
Las excavaciones han revelado una muralla polibastionada y un espacio habitacional en el centro del asentamiento con tres fases de uso, diferentes áreas funcionales y un hoyo votivo adscrito a la segunda fase.
En un hoyo ritual efectuado en la segunda fase se ha recuperado una cornamenta de cérvido que ha sido datado mediante AMS-14C. Se analizaron por Luminiscencia Ópticamente Estimulada (OSL) muestras de un nivel de uso de suelo asignado a la segunda fase (UE-9/10) y de la base de un horno asociado a la primera fase (UE- 18). Se aplicó un procedimiento de Dosis Única Regenerativa (SAR) sobre la fracción de granos de cuarzo de 90-160 μm. Se efectuó también un análisis de 7 muestras tomadas de la estratigrafía para determinar las variaciones de la conducta luminiscente y la edad relativa a través de la secuencia estratigráfica en muestras polimi- nerales mediante luminiscencia estimulada infrarojaópticamente y térmicamente (IRSl, OSL, TSL).
La datación y el perfil luminiscente indican que el nivel superior (UE-1B) pertenecería probablemente al Bronce Final (ca. 1000 AC), pero que el resto de la secuencia estratigráfica se corresponde con una ocupación del Neolítico Final-Edad del Cobre. Siendo lo más probable que la ocupación del sitio tuviera lugar entre el 3300 y el 2900 AC. Se detectan vacíos de ocupación entre la fase I y II, y entre la fase II y la ocupación del Bronce Final (fase III). Indicando que el asentamiento fue abandonado y reocupado en dos ocasiones, una en la Edad del Cobre y una en el Bronce Final. La fecha de 4254 ± 45 BP (3010-2675 cal AC) obtenida mediante AMS-14C coincide con las fechas luminiscente de la fase II, apuntando que el hoyo fue excavado al principio de la fase II.
Las fechas luminiscentes y radiocarbónicas combinadas muestran que el asentamiento de Las Mesas fue ocupado durante la colonización agrícola del territorio que tuvo lugar en el Neolítico Final, abandonado durante la Edad del Cobre y reocupado en el Bronce Final.
Los vacíos poblacionales registrados podrían relacionarse con las evidencias de quemado y destrucción parcial de la muralla del asentamiento, y su posterior reconstrucción y consolidación.The site of Las Mesas is located in the west bank of the Guadajira river (La Fuente, Badajoz, Spain). It covers a half hectare and is enclosed by a stone wall. Previous assessments based on site surveys suggested a general chronological span from Late Neolithic period (ca. 3600- 2900 BC) through the Copper Age (3rd millennium BC).
Excavations revealed a well-constructed wall with bastions and a domestic space at the centre of the site with three occupational phases. Several functional areas and a votive pit are ascribed to the second phase.
A deer antler located in a re-cut ritual pit associated to the second phase was dated by AMS-14C. Samples from a living floor assigned to the second phase (SU- 9/10) and the basement of a kiln associated with the first phase (SU-18) was dated by optically stimulated luminescence (OSL) using the single aliquot regenerative dose (SAR) protocol on 90-160 μm quartz grains. Luminescence profiling analysis of 7 samples taken throughout the archaeological stratigraphy was used to assess variations in luminescence behaviour and relative age through the sequence, using infrared-, optically –and thermally– stimulated luminescence (IRSL, OSL, TSL) on poly-mineral and etched samples.
Luminescence dating and profiling indicates that the upper archaeological layer (SU-1B) probably dates to the Late Bronze Age (ca. 1000 BC), but that the sediments in the remainder of this section accumulated during the late Neolithic-Copper Age: the site was most probably inhabited between 3300 and 2900 BC. There were gaps in occupation between the Late Neolithic-Cooper Age phases (I & II), and between the Late Neolithic-Cooper Age phases and Late Bronze Age phase (II & III), indicating that the site was abandoned and reoccupied twice.
The AMS-14C date on deer antler of 4254 ± 45 BP (3010- 2675 cal BC) is consisten with the OSL results for phase II, indicating that the pit was excavated at the beginning of the second occupational phase.
Combined OSL and AMS-14C dating shows that Las Mesas site was first occupied during Late Neolithic farming colonization, abandoned during the Copper Age and occupied again during the Late Bronze Age. The occupational gap recorded during the Copper Age relates to evidence for burning of the site and the partial destruction of the wall, followed by its reconstruction and consolidation
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