1,044 research outputs found
Effects of ohmic heating technology in chemical properties of foods
In this work some food products where characterised chemically before and after ohmic and
conventional heating treatments, comparing both processes. In each food type (cloudberry jam, goat
milk) pH was measured and parameters such as total and volatile solids, ash, titratable acidity,
ascorbic acid, total sugars, total fatty acids, total phenolic compounds and anthocyanins content
were determined, depending on the food being analysed. In goat milk samples treated by ohmic
technology, the titratable acidity 0.12 % (as lactic acid), pH value 6.59 and total fatty acids content
in milk fat 86.5 g 100gˉ¹ were comparable to those found in milk treated by conventional process. In
cloudberry jam samples treated by ohmic technology the results of some of the main parameters
tested, such as total sugar content 47.4 g 100gˉ¹, ascorbic acid concentration 2.8 g 100gˉ¹ and
titratable acidity 6.01g 100gˉ¹ (as citric acid) did not show significant differences for samples
treated by conventional technology
Ankle Foot Orthosis (AFO) stiffness design for mitigation of ankle inversion injury
Foundation for Science and Technology (FCT), through IDMEC, under LAETA [project number UID/EMS/50022/2019]. UNIDEMI [project number UID/EMS/00667/2019].Modelling and simulation of human movement has the potential to improve the design of medical devices and rehabilitation process by enabling the identification of cause-effect relationships in individuals suffering from neurological and musculoskeletal issues. The main goal of this work was to provide a simulation-based stiffness design for an Ankle Foot Orthosis (AFO) that can help to mitigate the risk of a sprain by ankle inversion during the landing in freefall which is known to occur for subtalar angles higher than 25 degrees. Computational simulations were performed using human movement models with and without a passive AFO, to access the AFO sensitivity for the translational stiffness that prevents the cuff from translating with respect to the footplate. The Design of Experiments (DoE) methodology was used to access sensitivities between the three principal directions of the AFO stiffness. Results revealed that the ankle inversion angle was less than 25 degrees when increasingly larger values of translational stiffness were used, although a nonlinear behaviour was observed between the three principal directions of the AFO stiffness, for which injury safe design configurations were obtained.authorsversionpublishe
Structural and functional stabilization of protein entities
XI Reunião Regional Nordeste da SBBq | 4th International Symposium in Biochemistry of Macromolecules and BiotechnologyStabilization of protein and protein-like molecules translates into preservation of both
structure and functionality during storage and/or targeting, and such stabilization is
mostly attained through establishment of a thermodynamic equilibrium with the
(micro)environment. The basic thermodynamic principles that govern protein structural
transitions and the interactions of the protein and/or peptide molecule with its
(micro)environment will, therefore, be tackled. Protein stabilization is based upon
dampening the molecular motions and, therefore, eliminating conformational transitions
while the molecule is still in the native 3D (folded) state. The 3D structure of a protein
molecule depends mostly on two types of interactions: intramolecular interactions
between aminoacid moieties and intermolecular interactions with solute and/or solvent
molecules present in its microenvironment. Stabilizing a biomolecule (aiming at
preserving its function) involves dampening its molecular motions, and this can be
achieved by reducing the chemical activity of the water present in its microenvironment,
thus stabilizing both its structure and functionality. Recently, the simultaneous
entrapment-stabilization of proteins and enzymes based on nanoencapsulation in a
nanoemulsion (W/O/W) matrix with an hydrophilic core has started to gain momentum.
Similarly to the stabilization mechanism of osmolytes, in nanoencapsulation the water
activity is altered thus affecting the molecular motions of the proteins. Highlights will also
be given to structural and functional stabilization of protein entities (viz. enzymes,
(macro)peptides, (recombinant) proteins, and bacteriophages) by chemical
methodologies. Modification of the biomolecules microenvironment via multipoint
covalent attachment onto a solid surface followed by hydrophylic polymer coimmobilization,
are some of the (latest) strategies that will be discussed.info:eu-repo/semantics/publishedVersio
Comparison of the adsorption of linear and cyclic antimicrobial peptides onto cellulosic compounds-reinforced poly(vinyl alcohol) films using QCM-D
Understanding peptide adsorption kinetics onto biomaterial surfaces is crucial for developing wound treatments. This study aims to explore the influence of cellulose acetate (CA) and cellulose nanocrystals (CNC) on peptide adsorption via quartz crystal microbalance with dissipation monitoring (QCM-D), using a cyclic peptide, Tiger 17, and a linear, Pexiganan. PVA was reinforced with 10 and 20% w/v of CA and CNC, spin-coated onto QCM-D sensors, and crosslinked with glutaraldehyde. Films containing higher percentages of cellulosic compounds promoted the highest peptide adsorption, with CNC-containing films being the most effective. While C80/20 PVA/CNC films achieved adsorption masses of ≈199 and ≈150 ng/cm2 for Tiger 17 and Pexiganan, respectively, the C80/20 PVA/CA films attained ≈168 and ≈122 ng/cm2 . The peptides’ structure also influenced adsorption, with Tiger 17 reaching greater frequency drops (ΔF) than Pexiganan. Sequential adsorption studies corroborated these findings. Even though the tendency was for PVA/CNC to promote the highest peptide binding, it was the PVA/CA films that reached the greatest peptide loading amount with the sequence Pexiganan + Tiger 17. Data are encouraging for developing new wound therapies reinforced with cellulosic compounds and modified with Tiger 17 and Pexiganan.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), Fulbright Scholarship Program, FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE) for funding the project with reference PTDC/CTM-TEX/28074/2017 (POCI-01–0145-FEDER028074). Authors also acknowledge project UID/CTM/00264/2020 of Centre for Textile Science and Technology (2C2T) on its components base (https://doi.org/10.54499/UIDB/00264/2020) and programmatic (https://doi.org/10.54499/UIDP/00264/2020). M.A.T., D.P.F and H.P. F. acknowledge FCT for PhD scholarship (SFRH/BD/148930/2019) and junior (CEECIND/02803/2017) and auxiliary researcher(2021.02720. CEECIND; https://doi.org/10.54499/DL57/2016/CP1377/CT0098) contracts, respectively
Renewable fuel production from hydropyrolysis of residual biomass using molybdenum carbide-based catalysts: An analytical Py-GC/MS investigation
Fast hydropyrolysis of lignocellulosic biomass was studied by using an analytical pyrolyzer coupled with a gas chromatography/mass spectrometry set-up (Py-GC/MS). Under pure H2 stream, Canadian pinewood was rapidly heated up to 500 °C and the generated vapors passed through a catalytic bed at 500 °C. Experiments were carried out in order to compare the catalytic performance of MoC/Al2O3 catalyst to a reference catalyst based on noble metal (1.5 wt.% Pt/Al2O3). The effect of different supports (Al2O3, ZrO2 and MgO) on the carbide performance and product formation was investigated. The results showed that the performance of MoC/Al2O3 was similar to that of 1.5 wt.% Pt/Al2O3. Both of them deoxygenated the hydropyrolysis vapors and led exclusively to hydrocarbons formation. However, the proportion of aliphatic and aromatic hydrocarbons was different: MoC/Al2O3 catalyst produced more aliphatics (57%) than the Pt catalyst. The supports have demonstrated influence on the product distribution. Acidity of the support seems to play an important role in the deoxygenation of the vapors. While there was complete removal of oxygen when MoC/Al2O3 and MoC/ZrO2 were used, the same did not take place for the more basic MoC/MgO catalyst
Impact of biological agents and tissue engineering approaches on the treatment of rheumatic diseases
The treatment of rheumatic diseases has been the focus of many clinical studies aiming to achieve the best
combination of drugs for symptom reduction. Although improved understanding of the pathophysiology of
rheumatic diseases has led to the identification of effective therapeutic strategies, its cure remains unknown.
Biological agents are a breakthrough in the treatment of these diseases. They proved to be more effective than the
other conventional therapies in refractory inflammatory rheumatic diseases. Among them, tumor necrosis factor
inhibitors are widely used, namely Etanercept, Infliximab, or Adalimumab, alone or in combination with
disease-modifying antirheumatic drugs. Nevertheless, severe adverse effects have been detected in patients with
history of recurrent infections, including cardiac failure or malignancy. Currently, most of the available therapies
for rheumatic diseases do not have sufficient tissue specificity. Consequently, high drug doses must be administrated
systemically, leading to adverse side effects associated with its possible toxicity. Drug delivery
systems, by its targeted nature, are excellent solutions to overcome this problem. In this review, we will describe
the state-of-the-art in clinical studies on the treatment of rheumatic diseases, emphasizing the use of biological
agents and target drug delivery systems. Some alternative novel strategies of regenerative medicine and its
implications for rheumatic diseases will also be discussed.The authors state that there is no conflict of interests, including financial, relationships, or affiliations relevant for the subject. M. Alves da Silva and A. Martins acknowledge the Portuguese Foundation for Science and Technology for their Ph.D. grants and European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Valorization of tomato by-products: influence of ohmic heating process on polyphenols extraction
Vienna Polyphenols 2017 - 11th World Congress on Polyphenols Applications[Excerpt] Introduction: Tomato based products is one of the worldwide major agroindustrial sectors generating substantial amounts of wastes, with high economic and environmental
costs[1]. These agroindustrial by-products e.g. skins and pulp remnants, are rich in bioactive compounds such as polyphenols [2–4]. Current extraction treatments,
besides representing environmental hazards, may cause these by-products bioactive compounds degradation, promote toxicity, and reduce biological properties
and health benefits, thus hampering their added value. Therefore, there is a growing interest in alternative extraction technologies, such as the case of Ohmic
Heating (OH), an environmentally-friendly technique (i.e. use of electrical energy) [5].
This study aimed to optimize the extraction of phenolic compounds, antioxidants and carotenoids of tomato wastes through ohmic heating, as an alternative
extraction technology. [...]The authors would like to thank to the project Co-promoção nº 016403, “MULTIBIOREFINERY”, supported by Programa Operacional Competitividade e
Internacionalização e pelo Programa Operacional Regional de Lisboa, na sua componente FEDER, e pela Fundação para a Ciência e Tecnologia and
project UID/Multi/50016/2013 , administrated by FCT. Furthermore, This study was supported by the Portuguese Foundation for Science and
Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and
BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa
Operacional Regional do Norte”The author Marta Coelho would like to acknowledge FCT for your PhD grant with the reference [grant number
SFRH/BD/111884/2015] and Ricardo Pereira SFRH/BPD/81887/2011.info:eu-repo/semantics/publishedVersio
Extraction of carotenoids supported by ohmic heating and characterization of biological properties and stability throughout gastrointestinal tract
The authors would like to thank to the project Co-promoção nº 016403, “MULTIBIOREFINERY”,
supported by Programa Operacional Competitividade e Internacionalização e pelo Programa
Operacional Regional de Lisboa, na sua componente FEDER, e pela Fundação para a Ciência e
Tecnologia and project UID/Multi/50016/2013, administrated by FCT. Furthermore, his study
was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope
of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-
0145-FEDER-000004) funded by the European Regional Development Fund under the scope of
Norte2020 - Programa Operacional Regional do Norte. The author Marta Coelho would like to
acknowledge FCT for your PhD grant with the reference [grant number SFRH/BD/111884/2015] .info:eu-repo/semantics/publishedVersio
Effect of batch and fed-batch growth modes on biofilm formation by Listeria monocytogenes at different temperatures
The influence of Listeria monocytogenes (L. monocytogenes) biofilm formation feeding conditions (batch and fed-batch) at different temperatures on biofilm biomass and activity was determined. Biofilm biomass and cellular metabolic activity were assessed by Crystal Violet (CV) staining and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt (XTT) colorimetric method, respectively. Live/Dead staining was also performed in order to get microscopic visualization of the different biofilms. Results revealed that at refrigeration temperature (4°C) a higher amount of biofilm was produced when batch conditions were applied, while at higher temperatures the fed-batch feeding condition was the most effective on biofilm formation. Moreover, independently of the temperature used, biofilms formed under fed-batch conditions were metabolically more active than those formed in batch mode. In conclusion, this work shows that different growth modes significantly influence L. monocytogenes biofilm formation on abiotic surfaces as well as the metabolic activity of cells within biofilms.Fundação para a Ciência e a Tecnologia (FCT) - PPCDT/AGR/59358/2004, SFRH/
BD/28887/2006, SFRH/BPD/26803/200
The interplay between atmospheric conditions and grape berry quality parameters in Portugal
The atmospheric conditions are a strong modulator of grape berry composition, but further research is required to better understand this relationship, which is particularly pertinent under the context of climate change. The present study assesses the relationship between interannual variability in atmospheric conditions (mean, maximum and minimum air temperatures and precipitation totals) on grape berry quality attributes in three main Portuguese wine regions—Douro, Dão and Alentejo—and targets two major varieties growing in Portugal (cv. Touriga Nacional and cv. Aragonez/Tempranillo). Berry weight, titratable acidity (TA), pH, potential alcohol (PA), anthocyanins and total phenols index (TPI) data, collected two to three weeks after the end of the veraison until technological maturity, since 1999 in Douro, 2004 in Alentejo and 2008 in Dão, were selected. Meteorological data were obtained from both automatic weather stations and a climatic database defined at a very-high-resolution grid (<1 km) (PTHRES). The influence of daily mean, maximum and minimum air temperatures (November–October) and precipitation totals (April to June and July to September) on the above-mentioned berry quality parameters were first explored to identify the months/periods more influential to grape berry composition. Different statistical approaches were subsequently carried out to explore in greater detail these relationships. At technological maturity, temperature was negatively correlated to berry weight, titratable acidity, anthocyanins and TPI, but was positively correlated to pH and potential alcohol. Moreover, lowest levels of berry weight and TA (and highest levels of pH) were more frequent in warmer regions, while the opposite was seen in the cooler regions. PA, TPI and anthocyanins at maturity did not show a clear trend across regions. In addition, the maturation parameters of each site were grouped into two clusters—years where the maturation parameter is higher (cluster 1) and years where it is lower (cluster 2)—and significant differences in monthly mean temperatures between clusters were found. Overall, temperatures at veraison and maturation periods (June–August) were more influential in determining grape berry composition at harvest. The influence of precipitation was dependent on location and variety. The results also suggested that berry composition in Alentejo is more sensitive to atmospheric variability, while Aragonez seems more resilient than Touriga Nacional. These outcomes are based on a systematized and unprecedentedly large grape berry quality database in Portugal and provided the grounds for the development of grape quality forecast models, either to be used operationally in each vintage or for assessing potential modifications in berry composition in response to changing climates.This study was funded by the Clim4Vitis project-"Climate change impact mitigation for European viticulture: knowledge transfer for an integrated approach", funded by European Union's Horizon 2020 Research and Innovation Programme, under grant agreement no. 810176.info:eu-repo/semantics/publishedVersio
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