535 research outputs found
Natural phytochemicals and probiotics as bioactive ingredients for functional foods: Extraction, biochemistry and protected-delivery technologies
he well-known correlation between diet and physiology demonstrates the great possibilities of food to maintain or improve our health, increasing the interest in finding new products with positive physiological effects. Nowadays, one of the top research areas in Food Science and Technology is the extraction and characterization of new natural ingredients with biological activity that can be further incorporated into a functional food, contributing to consumer's well-being. Furthermore, there is a high demand for effective encapsulation methodologies to preserve all the characteristics of bioactive compounds until the physiological action site is reached. Scope and approach: In this review, the relevance of developing standard approaches for the extraction of the highly diverse bioactive compounds was described, as it defines the suitability of the following steps of separation, identification and characterization. Special attention was also dedicated to the encapsulation techniques used on hydrophilic and/or lipophilic compounds (e.g., emulsification, coacervation, supercritical fluid, inclusion complexation, emulsification-solvent evaporation and nanoprecipitation). Key findings and conclusions: Some useful conclusions regarding the selection of the best extraction methodology (Soxhlet extraction, ultrasound-assisted extraction, supercritical fluid extraction, accelerated solvent extraction, or shake extraction) were achieved, considering important aspects such as cost, required technical skills, extract integrity, green chemistry principles, solvent type, sample size, pH, temperature and pressure. In addition, this comprehensive review allowed defining the best protective approach to solve the limitations related to the extremely low absorption and bioavailability of bioactive phytochemicals, overcoming problems related to their low solubility, poor stability, low permeability and metabolic processes in the GI tract.info:eu-repo/semantics/publishedVersio
Efeitos sinergistas da atividade antioxidante de cogumelos comestíveis: mistura de extratos fenólicos e polissacarídicos de Boletus edulis e Marasmius oreades.
Neste trabalho, avaliou-se a atividade antioxidante de diferentes misturas de Marasmius oreades e Boletus edulis (12,5/87,5, 25/75, 50/50, 75/25, 87,5/12,5) e comparou-se com os controlos (amostras individuais), com o objetivo de verificar qual das misturas contribui para efeitos sinergistas. As propriedades antioxidantes foram avaliadas por quatro métodos químicos e bioquímicos, sendo ainda determinados os fenóis totais (extratos fenólicos) e o teor em polissacáridos (extratos polissacarídicos). Foram observadas três tipos de interações utilizando as diferentes misturas de cogumelos: efeitos aditivos, sinergistas e antagonistas. Os resultados obtidos mostraram diferentes comportamentos nos ensaios de atividade antioxidante de acordo com as proporções utilizadas, indicando que as misturas de cogumelos permitem a ocorrência de diferentes interações químicas entre os compostos obtidos em cada espécie. Todas as diferentes proporções utilizadas de cada cogumelo demonstraram ter atividade antioxidante e, independentemente das proporções utilizadas, os extratos polissacarídicos apresentaram maior atividade antioxidante que os extratos fenólicos. Verificou-se também que a mesma mistura pode induzir um efeito sinergista num método de atividade antioxidante e um efeito antagonista noutro método de atividade antioxidante
Insights in the antioxidant synergistic effects of combined edible mushrooms: phenolic and polysaccharidic extracts of Boletus edulis and Marasmius oreades
In a previous work, we reported the presence of Marasmius oreades in mixtures with antioxidant synergistic effects, and
the mixture Boletus edulis and Marasmius oreades (50% of each) as having the highest antioxidant activity, but without
synergism among the phenolic extracts. Herein, phenolic and polysaccharidic extracts from both species were combined
in different proportions (12.5, 25, 50, 75 and 87.5%) and compared to controls (individual samples), in order to give
insight in the contribution of each species to antioxidant synergistic effects. The antioxidant activity of the individual
or combined extracts obtained from both edible mushrooms was evaluated through their 2,2-diphenyl-1-picrylhydrazyl
(DPPH) radical-scavenging activity, reducing power, -carotene bleaching inhibition and lipid peroxidation inhibition
in brain homogenates using thiobarbituric acid reactive substances (TBARS) assay. Synergism was the main observed
effect among the combined extracts, either phenolic or polysaccharidic. However, the effect of each B. edulis and
M. oreades proportion was not the same for all antioxidant activity assays. In fact, the same mixture exhibited sometimes
opposite behaviours according with the performed antioxidant activity assay
Optimization of the supercritical fluid extraction of Quercus cerris cork towards extraction yield and selectivity to friedelin
Optimization of the supercritical fluid extraction of Quercus cerris cork was carried out using Box-Behnken design
of experiments and response surface methodology (RSM). The optimized process variables were temperature (T :
40, 50 and 60 °C), ethanol content (EtOH: 0.0, 2.5 and 5.0 wt%) and CO2 flow rate (QCO2: 5, 8 and 11 −g min )1 .
The studied responses were total extraction yield (ηTotal), friedelin concentration of the extract (CFriedelin), and
selectivity towards friedelin (αF,nF). The linear effect of EtOH was by far the most influent operating condition
(Pareto analysis) and the highest yield (ηTotal = 2.2 wt%) was attained with 5.0 wt% EtOH. The RSM model
estimates maximum friedelin concentration in the extracts (38.2 wt%) to occur without cosolvent (0 wt% EtOH)
for the lowest T (40 °C) and QCO2 (5 −g min )CO2
1 . As for selectivity, the experimental αF,nF values were always
higher than 1.0 and reached 3.1 (at 50 °C, 5 wt% EtOH, 11 −g minCO2
1). Altogether, these results suggest
friedelin can be selectively removed from Quercus cerris cork by supercritical fluid extraction within the range of
experimental conditions studiedpublishe
Validation of microbiological assay for determination of cefuroxime in injectable preparations
The validation of a microbiological assay, applying agar diffusion method for determination of the active of cefuroxime in power for injection, is described. Using a strain of Micrococcus luteus ATCC 9341 as the test organism, cefuroxime was measured in concentrations ranging from 30.0 to 120.0 μg/mL.
The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 0.37 %) and accurate (it measured the added quantities). Microbiological assay is satisfactory for quantitation of cefuroxime in powder for injection and the validity of the proposed bioassay, which is a simple and a useful alternative methodology for cefuroxime determination in routine quality control.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Effect of plant biostimulants on nutritional and chemical profiles of almond and hazelnut
The increasing interest in natural foods with functional effects demands progressively
higher production levels. Nonetheless, there is an orientation towards practicing more sustainable
agriculture, free from environmentally harmful pesticides and fertilizers. Plant biostimulants, a
class of bio-based agriculture products designed to improve crop development, represent a feasible
alternative to chemical fertilizers, or, at least, an effective way of reducing the employed quantities.
Herein, different types of plant biostimulants compatible with organic farming (Phytoalgae, Foliar B,
Amino Acids, Soil B, Fitoalgas Green® and Sprint Plus®) were tested in two of the most important
nut products worldwide: almonds and hazelnuts, which were tested for nutritional parameters, fatty
acids profiles and tocopherols contents. Overall, the most notorious effects in almond samples were
obtained with phytoalgae (seaweed Ascophyllum nodosum extracts), particularly reflected in the
upraising around 10% of
-tocopherol and -tocopherol contents. Likewise, hazelnuts treated with
NPK + phytoalgae were also characterized by an increase of almost 18% in tocopherols levels, while
treatment with NPK alone induced 15.1% higher percentage of linoleic acid.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); to the
national funding by FCT, P.I., through the institutional scientific employment program-contract for
L. Barros and individual scientific employment program-contract (CEECIND/04479/2017). Further
acknowledgments are due to the European Regional Development Fund (ERDF) through the
Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-
FEDER-024479: ValorNatural®, whom the author F.S. Reis thanks for her contract. This work
was also funded by FEDER-Interreg España-Portugal programme through the project TRANSCo-
LAB 0612_TRANS_CO_LAB_2_P, and integrated in the activities of the Operational Group EGIS–
Estratégias de Gestão Integrada do Solo e da Água em Espécies Produtoras de Frutos Secos, funded
by PT2020 and EAFRD (European Agricultural Fund for Rural Development).info:eu-repo/semantics/publishedVersio
Superconductivity in the SU(N) Anderson Lattice at U=\infty
We present a mean-field study of superconductivity in a generalized N-channel
cubic Anderson lattice at U=\infty taking into account the effect of a
nearest-neighbor attraction J. The condition U=\infty is implemented within the
slave-boson formalism considering the slave bosons to be condensed. We consider
the -level occupancy ranging from the mixed valence regime to the Kondo
limit and study the dependence of the critical temperature on the various model
parameters for each of three possible Cooper pairing symmetries (extended s,
d-wave and p-wave pairing) and find interesting crossovers. It is found that
the d- and p- wave order parameters have, in general, very similar critical
temperatures. The extended s-wave pairing seems to be relatively more stable
for electronic densities per channel close to one and for large values of the
superconducting interaction J.Comment: Seven Figures; one appendix. Accepted for publication in Phys. Rev.
Localized Intersections of Non-Extremal p-branes and S-branes
A class of solutions to Supergravity in 10 or 11 dimensions is presented
which extends the non-standard or semi-local intersections of Dp-branes to the
case of non-extremal p-branes. The type of non-extremal solutions involved in
the intersection is free and we provide two examples involving black-branes
and/or D-\bar{D} systems. After a rotation among the time coordinate and a
relatively transverse radial direction the solutions admit the interpretation
of an intersection among D-branes and S-branes. We speculate on the relevance
of these configurations both to study time dependent phenomena in the AdS/CFT
correspondence as well as to construct cosmological brane-world scenarios
within String Theory admitting accelerating expansion of the Universe.Comment: 31 pages, latex file; v2: typos corrected and references adde
Measure representation and multifractal analysis of complete genomes
This paper introduces the notion of measure representation of DNA sequences.
Spectral analysis and multifractal analysis are then performed on the measure
representations of a large number of complete genomes. The main aim of this
paper is to discuss the multifractal property of the measure representation and
the classification of bacteria. From the measure representations and the values
of the spectra and related curves, it is concluded that these
complete genomes are not random sequences. In fact, spectral analyses performed
indicate that these measure representations considered as time series, exhibit
strong long-range correlation. For substrings with length K=8, the
spectra of all organisms studied are multifractal-like and sufficiently smooth
for the curves to be meaningful. The curves of all bacteria
resemble a classical phase transition at a critical point. But the 'analogous'
phase transitions of chromosomes of non-bacteria organisms are different. Apart
from Chromosome 1 of {\it C. elegans}, they exhibit the shape of double-peaked
specific heat function.Comment: 12 pages with 9 figures and 1 tabl
Metabolic and nutritional triggers associated with increased risk of liver complications in SARS-CoV-2
Obesity, diabetes, cardiovascular and respiratory diseases, cancer and smoking are risk factors for negative outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can quickly induce severe respiratory failure in 5% of cases. Coronavirus disease-associated liver injury may occur during progression of SARS-CoV-2 in patients with or without pre-existing liver disease, and damage to the liver parenchyma can be caused by infection of hepatocytes. Cirrhosis patients may be particularly vulnerable to SARS-CoV-2 if suffering with cirrhosis-associated immune dysfunction. Furthermore, pharmacotherapies including macrolide or quinolone antibiotics and steroids can also induce liver damage. In this review we addressed nutritional status and nutritional interventions in severe SARS-CoV-2 liver patients. As guidelines for SARS-CoV-2 in intensive care (IC) specifically are not yet available, strategies for management of sepsis and SARS are suggested in SARS-CoV-2. Early enteral nutrition (EN) should be started soon after IC admission, preferably employing iso-osmolar polymeric formula with initial protein content at 0.8 g/kg per day progressively increasing up to 1.3 g/kg per day and enriched with fish oil at 0.1 g/kg per day to 0.2 g/kg per day. Monitoring is necessary to identify signs of intolerance, hemodynamic instability and metabolic disorders, and transition to parenteral nutrition should not be delayed when energy and protein targets cannot be met via EN. Nutrients including vitamins A, C, D, E, B6, B12, folic acid, zinc, selenium and ω-3 fatty acids have in isolation or in combination shown beneficial effects upon immune function and inflammation modulation. Cautious and monitored supplementation up to upper limits may be beneficial in management strategies for SARS-CoV-2 liver patients
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