Ângelo C. Salvador

Ângelo C. Salvador


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
8 February 2010 in Green Chemistry
Verified
Journal Article
Closed access
PDF file
ÂSÂngelo C. Salvador
Ângelo C. Salvador
MSMickael da C. Santos
Mickael da C. Santos
JSJorge Manuel Alexandre Saraiva
Jorge Manuel Alexandre Saraiva
The effect of the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl) and of high pressure on the activity of cellulase from Aspergillus niger were studied separately and in combination. The enzyme activity decreased with increasing concentrations of [bmim]Cl, reaching 50% the value in aqueous buffer with 20% [bmim]Cl. However, when the enzyme is held in 10% [bmim]Cl and is then assayed in 1% [bmim]Cl, it showed only 8% reduction of activity. These results can be explained by the fact that the activity of the enzyme in [bmim]Cl is linearly correlated with the decrease of the thermodynamic water activity (aw). Under pressure the enzyme activity varied from less 60% (at 200MPa) to equal (at 400 MPa), compared to atmospheric pressure. In 10% [bmim]Cl under pressure, cellulase activity is improved compared to atmospheric pressure, varying from equal (at 600 MPa) to 1.7-fold higher (at 100 MPa). This opens the possibility to improve cellulase activity in ionic liquids, and possibly of other enzymes, by carrying out the reaction under pressure.

1 September 2015 in Industrial Crops and Products
Verified
Journal Article
Closed access
ÂSÂngelo C. Salvador
Ângelo C. Salvador
Silvia RochaSilvia Rocha
Silvia Rocha
Armando SilvestreArmando Silvestre
Armando Silvestre

Verified
Journal Article
Open access
PDF file
ÂSÂngelo C. Salvador
Ângelo C. Salvador
EKEwelina Król
Ewelina Król
VLVirgínia C. Lemos
Virgínia C. Lemos
Sonia SantosSonia Santos
Sonia Santos
FBFernanda P. M. S. Bento
Fernanda P. M. S. Bento
Silvia RochaSilvia Rocha
Silvia Rocha
Elderberry (Sambucus nigra L.) lipophilic and polar extract dietary supplementation effects were evaluated according to diabetes management indices, using an in vivo model. A research pipeline was constructed, that ranged from extract preparation, partial chemical characterization and toxicity evaluation, to examining the elderberry extract dietary supplementation effects on biofluid and tissues. Extracts toxicity was screened using an Aliivibrio fischeri bioluminescence model. A concentration of up to 60 mg/L was selected, and rat doses for oral supplementation were computed applying the interspecies correlation between A. fischeri and rats. Wistar type 2 diabetic rats, induced by streptozotocin (STZ), were fed a high-fat diet and supplemented for 4 weeks at doses of 190 and 350 mg/kg body weight/day of lipophilic and polar extract, respectively. As far as we know, lipophilic elderberry extract supplementation was assessed for the first time, while polar extract was administrated at higher doses and for a shorter period compared to previous studies, aiming to evaluate subacute supplementation effects. The polar extract modulated glucose metabolism by correcting hyperglycemia, while the lipophilic extract lowered insulin secretion. Both extracts lowered insulin resistance, without remarkable alterations to hematological indices, sera lipids and sera and tissular trace element homeostasis. In conclusion, elderberries are a potential source of bioactive compounds for formulations to be used as co-adjuvants in diabetes management.

16 April 2013 in PLOS ONE
Verified
Journal Article
Open access
PDF file
ÂSÂngelo C. Salvador
Ângelo C. Salvador
IBInês Baptista
Inês Baptista
ABAntonio Barros
Antonio Barros
NGNewton Gomes
Newton Gomes
Angela CunhaAngela Cunha
Angela Cunha
Silvia RochaSilvia Rocha
Silvia Rocha
A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level ( ca . 70 min versus ca . 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination ( ca . 70 min versus ca . 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC–ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC–ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans.

1 September 2012 in Estuarine, Coastal and Shelf Science
Verified
Journal Article
Closed access
VOVanessa Oliveira
Vanessa Oliveira
ASAna L. Santos
Ana L. Santos
CAClaúdia Aguiar
Claúdia Aguiar
LSLuisa Santos
Luisa Santos
ÂSÂngelo C. Salvador
Ângelo C. Salvador
Angela CunhaAngela Cunha
Angela Cunha

Verified
Journal Article
Open access
PDF file
DFDaniela Fonseca
Daniela Fonseca
ÂSÂngelo C. Salvador
Ângelo C. Salvador
Sonia SantosSonia Santos
Sonia Santos
Carla VilelaCarla Vilela
Carla Vilela
Carmen FreireCarmen Freire
Carmen Freire
Silvia RochaSilvia Rocha
Silvia Rocha
The lipophilic composition of wild Arbutus unedo L. berries, collected from six locations in Penacova (center of Portugal), as well as some general chemical parameters, namely total soluble solids, pH, titratable acidity, total phenolic content and antioxidant activity was studied in detail to better understand its potential as a source of bioactive compounds. The chemical composition of the lipophilic extracts, focused on the fatty acids, triterpenoids, sterols, long chain aliphatic alcohols and tocopherols, was investigated by gas chromatography–mass spectrometry (GC–MS) analysis of the dichloromethane extracts. The lipophilic extractives of the ripe A. unedo berries ranged from 0.72% to 1.66% (w/w of dry weight), and consisted mainly of triterpenoids, fatty acids and sterols. Minor amounts of long chain aliphatic alcohols and tocopherols were also identified. Forty-one compounds were identified and among these, ursolic acid, lupeol, α-amyrin, linoleic and α-linolenic acids, and β-sitosterol were highlighted as the major components. To the best of our knowledge the current research study provides the most detailed phytochemical repository for the lipophilic composition of A. unedo, and offers valuable information for future valuation and exploitation of these berries.