2,179 research outputs found
Microencapsulation of ellagic acid from pomegranate husk and karaya gum by spray drying
Objective: The aim of this study was to obtain and characterize microcapsules with Ellagic Acid (EA) from pomegranate as core material and Karaya Gum (KG) as wall material.
Methods: EA was obtained from dry pomegranate peel powder via methanolysis and quantified by HPLC. Microcapsules were obtained preparing a dispersion containing KG and EA in phosphate buffer pH 8. The dispersion was processed in a spray dryer under specific conditions (inlet temperature at 150 °C, feed flow at 30% and aspirator at 100 %) for obtaining of microcapsules. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used for characterization.
Results: Obtained material contains 98.03±2.82 mg EA/g of pomegranate peel. FTIR showed that there were changes in the molecular structure of microcapsules referred to raw materials. SEM confirmed that particles obtained had micron-size (1-5 µm). DSC analysis showed that raw materials had glass transition temperatures of 79.58 and 83.41 °C and for microcapsules the value was67.25 °C.
Conclusion: Methanolysis is a viable technique for the obtaining of EA from the peel of pomegranate. KG shows good potential for be used as wall material for EA microencapsulation
Typical Mexican agroindustrial residues as supports for solid-state fermentation
Biological wastes contain several reusable substances of high value such as soluble sugars and fiber. Direct disposal of such wastes to soil or landfill causes serious environmental problems. Thus, the development of potential value-added processes for these wastes is highly attractive. These biological wastes can be used as support-substrates in Solid-State Fermentation (SSF) to produce industrially relevant metabolites with great economical advantage. In addition, it is an environment friendly method of waste management. In this study were analyzed six different Mexican agro industrial residues to evaluate their suitability as support-substrate in SSF, between physicochemical properties that have included Water Absorption Index (WAI), Critical Moisture Point (CHP) and Packing Density (PD). The selection of an appropriate solid substrate plays an important role in the development of an efficient SSF process. The results provided important knowledge about the characteristics of these materials revealing their potential for use in fermentation processes.(undefined
EM simulation of a low-pass filter based on a microstrip defected ground structure using COMSOL
We perform EM simulations of a lowpass microstrip filter consisting of a crossjunction open stub and two unit sections implemented as defected ground structures (DGS). The defect introduced by unit sections corresponds to an etched lattice on the copper backside ground plane. The filter presents wide and deep attenuation characteristics in the stopband. Different model implementations were carried out with the aim at evaluating the computational costs versus accuracy. Simulations of a high-fidelity model are in good agreement with experimental data reported in a previous paper. COMSOL simulation settings, enclosing box, computational costs, and simulation times for the considered models are provided.ITESO, A.C.Intel Guadalajara Design Cente
Enhancement of fructosyltransferase and fructooligosaccharides production by A. oryzae DIA-MF in Solid-State Fermentation using aguamiel as culture medium
The aim of this work was to improve the production of fructosyltransferase (FTase) by Solid-State Fermentation (SSF) using aguamiel (agave sap) as culture medium and Aspergillus oryzae DIA-MF as producer strain. SSF was carried out evaluating the following parameters: inoculum rate, incubation temperature, initial pH and packing density to determine the most significant factors through Box-Hunter and Hunter design. The significant factors were then further optimized using a Box-Behnken design and response surface methodology. The maximum FTase activity (1347 U/L) was obtained at 32 °C, using packing density of 0.7 g/cm3. Inoculum rate and initial pH had no significant influence on the response. FOS synthesis applying the enzyme produced by A. oryzae DIA-MF was also studied using aguamiel as substrate.Authors thank National Council for Science and Technology (CONACYT) of Mexico by the financial support through the project No. CB-2011-C01-167764. Author D. B. Muñiz-Márquez also thank CONACYT for the financial support during her postgraduate program (Doctorate) in Food Science and Technology offered by the University Autonomous of Coahuila, Mexico
A specific structure and high richness characterize intestinal microbiota of HIVexposed seronegative individuals
Intestinal microbiota facilitates food breakdown for energy metabolism and influences the im-mune response and maintaining mucosal homeostasis. Overall, HIV infection is associated with intestinal dysbiosis and immune activation, which has been related to seroconversion in HIV-exposed individuals. However, to date, it is unclear whether microbiota dysbiosis is the cause or the effect of immune alterations and disease progression. We characterize the intestinal microbiota and determine its association with immune regulation in HIV-exposed seronegative individuals (HESN), HIV-infected progressors (HIV+), and healthy control (HC) subjects. For this, feces and blood were collected. The microbiota composition of HESN showed a significantly higher alpha and beta diversity compared to HC, but similar to HIV+. A lower Treg percentage was observed in HESN than HC and HIV+, with enrichment of the genus Butyrivibrio being characteristic of this profile. Interestingly, an increase in Succinivibrio and Prevotella and a re-duction in Bacteroides genus were observed in HESN compared to HC, which is typical of HIV-infected individuals. Thus, HESNs have a microbiota profile, similar to that observed in HIV+, most likely because HESN are cohabiting with their HIV+ partners.Intestinal microbiota facilitates food breakdown for energy metabolism and influences the im-mune response and maintaining mucosal homeostasis. Overall, HIV infection is associated with intestinal dysbiosis and immune activation, which has been related to seroconversion in HIV-exposed individuals. However, to date, it is unclear whether microbiota dysbiosis is the cause or the effect of immune alterations and disease progression. We characterize the intestinal microbiota and determine its association with immune regulation in HIV-exposed seronegative individuals (HESN), HIV-infected progressors (HIV+), and healthy control (HC) subjects. For this, feces and blood were collected. The microbiota composition of HESN showed a significantly higher alpha and beta diversity compared to HC, but similar to HIV+. A lower Treg percentage was observed in HESN than HC and HIV+, with enrichment of the genus Butyrivibrio being characteristic of this profile. Interestingly, an increase in Succinivibrio and Prevotella and a re-duction in Bacteroides genus were observed in HESN compared to HC, which is typical of HIV-infected individuals. Thus, HESNs have a microbiota profile, similar to that observed in HIV+, most likely because HESN are cohabiting with their HIV+ partners.https://scienti.minciencias.gov.co/cvlac/EnProdArticulo/query.do?cod_producto=73&cod_rh=0000157775https://scholar.google.com.co/citations?hl=en&user=VLZxl1UAAAAJCOL0112548https://orcid.org/0000-0002-7351-873
Fructo-oligosaccharides (FOS) production by fungal submerged culture using aguamiel as a low-cost by-product
Supplementary data to this article can be found online at https:// doi.org/10.1016/j.lwt.2018.12.020.Fructooligosaccharides (FOS) are important ingredients in the functional food industry because they have different biological properties such as decrease level of triglycerides, cholesterol and phospholipids and stimulate growth of probiotics for enhancement of microflora in large intestine. However, current strategies for the FOS production through simple and economical bioprocess has been necessary. The aim of this work was evaluated the capacity of three fungal strains (Aspergillus niger GH1, Aspergillus niger PSH and Aspergillus oryzae DIA-MF) to produce fructooligosaccharides (FOS) using aguamiel from Agave salmiana as an economical substrate. In addition, Czapek Dox medium supplemented with sucrose as carbon source was used as a control medium for the FOS production. A. oryzae DIA-MF was a fungi producer of FOS using aguamiel or Czapek Dox medium as substrate at 24?h of fermentation. However, the yield of FOS was increased two folds (20.30?g/L), with a productivity of 0.84?g FOS/l.h when aguamiel was used as substrate. On the other hand, A. niger GH1 and A. niger PSH showing only hydrolytic activity on sucrose under the studied conditions. In conclusion, this study shown excellent compatibility of A. oryzae DIA-MF using aguamiel as an economical substrate for the FOS production under a simple bioprocess.Authors thank all technical support and comments made by Dra. Adriana C. Flores-Gallegos and Dra. Abril Flores-Maltos. Authors thank National Council for Science and Technology (CONACYT) of Mexico by the financial support through the project No. CB-2011-C01-167764. Author D. B. Muñiz-Márquez also thank CONACYT for the financial support during her postgraduate program (Doctorate) in Food Science and Technology offered by the University Autonomous of Coahuila, Mexico.info:eu-repo/semantics/publishedVersio
l W nu production at CLIC: a window to TeV scale non-decoupled neutrinos
We discuss single heavy neutrino production e+ e- -> N nu -> l W nu, l = e,
mu, tau, at a future high energy collider like CLIC, with a centre of mass
energy of 3 TeV. This process could allow to detect heavy neutrinos with masses
of 1-2 TeV if their coupling to the electron V_eN is in the range 0.004-0.01.
We study the dependence of the limits on the heavy neutrino mass and emphasise
the crucial role of lepton flavour in the discovery of a positive signal at
CLIC energy. We present strategies to determine heavy neutrino properties once
they are discovered, namely their Dirac or Majorana character and the size and
chirality of their charged current couplings. Conversely, if no signal is
found, the bound V_eN < 0.002-0.006 would be set for masses of 1-2 TeV,
improving the present limit up to a factor of 30. We also extend previous work
examining in detail the flavour and mass dependence of the corresponding limits
at ILC, as well as the determination of heavy neutrino properties if they are
discovered at this collider.Comment: LaTeX 32 pages. Added comments and references. Matches version to
appear in JHE
Successive fermentation of aguamiel and molasses by Aspergillus oryzae and Saccharomyces cerevisiae to obtain high purity fructooligosaccharides
Fructooligosaccharides (FOS) are usually synthesized with pure enzymes using highly concentrated sucrose solutions. In this work, low-cost aguamiel and molasses were explored as sucrose alternatives to produce FOS, via whole-cell fermentation, with an Aspergillus oryzae DIA-MF strain. FOS production process was optimized through a central composite experimental design, with two independent variables: initial sucrose concentration in a medium composed of aguamiel and molasses (AgMe), and inoculum concentration. The optimized process—165 g/L initial sucrose in AgMe (adjusted with concentrated molasses) and 1 × 107 spores/mL inoculum concentration—resulted in an FOS production of 119 ± 12 g/L and a yield of 0.64 ± 0.05 g FOS/g GFi. Among the FOSs produced were kestose, nystose, 1-fructofuranosyl-nystose, and potentially a novel trisaccharide produced by this strain. To reduce the content of mono- and disaccharides in the mixture, run a successive fermentation was run with two Saccharomyces cerevisiae strains. Fermentations run with S. cerevisiae S227 improved FOS purity in the mixture from 39 ± 3% to 61.0 ± 0.6% (w/w) after 16 h of fermentation. This study showed that agro-industrial wastes such as molasses with aguamiel are excellent alternatives as substrate sources for the production of prebiotic FOS, resulting in a lower-cost process.Orlando de la Rosa acknowledges the National Council of Science and Technology (CONACYT-Mexico) for the financial support given through the PBM (Program Becas Mixtas) (CVU 860996) and the APC was funded by Universidad Autónoma de Coahuila (Mexico). The study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the Project ColOsH PTDC/BTM-SAL/30071/2017 (POCI-01-0145-FEDER-030071).info:eu-repo/semantics/publishedVersio
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