Sensorically Active Compounds
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Ovocné destiláty jsou alkoholické nápoje s dlouhou tradicí výroby i konzumace po celém světě. Společnými kroky výroby všech druhů ovocných destilátů jsou příprava ovocného kvasu a jeho následná destilace. Způsobem provedení výroby ovocných destilátů je možné ovlivnit jejich složení a organoleptické vlastnosti. Tento článek představuje náhled do problematiky vlivu výrobní technologie na analytický profil ovocných destilátů a do souvislostí mezi složením destilátů a jejich organoleptickými vlastnostmi. Popsán je zde také právní rámec výroby a distribuce ovocných destilátů.
Fruit spirits are alcoholic beverages and their production and consumption has a long tradition all around the world. Common steps in production of all kinds of fruit spirits are fermentation and distillation of fermented mash. The manner in which the production process is carried out can affect the composition and organoleptic properties of fruit spirits. This article is a swift preview of problematics of relations between production technology of fruit spirits, their composition and organoleptic properties. It also describes legislation of production and distribution of fruit distillates.
Magnetic particles (MPs) have been widely used in biological applications in recent years as a carrier for various molecules. Their big advantage is in repeated use of immobilized molecules including enzymes. Acetylcholinesterase (AChE) is an enzyme playing crucial role in neurotransmission and the enzyme is targeted by various molecules like Alzheimer's drugs, pesticides and warfare agents. In this work, an electrochemical biosensor having AChE immobilized onto MPs and stabilized through glutaraldehyde (GA) molecule was proposed for assay of the neurotoxic compounds. The prepared nanoparticles were modified by pure AChE and they were used for the measurement anti-Alzheimer's drug galantamine and carbamate pesticide carbofuran with limit of detection 1.5 µM and 20 nM, respectively. All measurements were carried out using screen-printed sensor with carbon working, silver reference, and carbon auxiliary electrode. Standard Ellman's assay was used for validation measurement of both inhibitors. Part of this work was the elimination of reversible inhibitors represented by galantamine from the active site of AChE. For this purpose, we used a lower pH to get the original activity of AChE after inhibition by galantamine. We also observed decarbamylation of the AChE-carbofuran adduct. Influence of organic solvents to AChE as well as repeatability of measurement with MPs with AChE was also established.
The new screening method for rapid evaluation of major phenolic compounds in apples has been developed. Suitability of coupling HPLC/UHPLC separation with the diode-array detection and universal charged aerosol detection with respect to the presence of interfering substances was tested. Characteristics of both detection techniques were compared and method linearity, limits of detection and quantitation, and selectivity of them determined. Student t-test based on slopes of calibration plots was applied for the detailed comparison. The diode-array detection provided the best results regarding sensitivity and selectivity of the developed method in terms of evaluation of phenolics profiles. The response of the charged aerosol detector was negatively affected by co-eluting substances during rapid-screening analyses. Coulometric detection was used for advanced characterization of extracts in terms of antioxidant content and strength to obtain more complex information concerning sample composition. This detection also allowed evaluation of unidentified compounds with antioxidant activity. HPLC/UHPLC separation using a combination of diode-array and coulometric detectors thus represented the best approach enabling quick, yet complex characterization of bioactive compounds in apples.
- MeSH
- aerosoly chemie MeSH
- antioxidancia chemie MeSH
- chromatografie metody MeSH
- elektrochemie metody MeSH
- fenol chemie MeSH
- fenoly analýza MeSH
- kalibrace MeSH
- limita detekce MeSH
- Malus metabolismus MeSH
- potravinářská technologie MeSH
- reprodukovatelnost výsledků MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
Much effort has been made to standardise sampling procedures, laboratory analysis, data analysis, etc. for semi volatile organic contaminants (SVOCs). Yet there are some unresolved issues in regards to comparing measurements from one of the most commonly used passive samplers (PAS), the polyurethane foam (PUF) disk PAS (PUF-PAS), between monitoring networks or different studies. One such issue is that there is no universal means to derive a sampling rate (Rs) or to calculate air concentrations (Cair) from PUF-PAS measurements for SVOCs. Cair was calculated from PUF-PAS measurements from a long-term monitoring program at a site in central Europe applying current understanding of passive sampling theory coupled with a consideration for the sampling of particle associated compounds. Cair were assessed against concurrent active air sampler (AAS) measurements. Use of "site-based/sampler-specific" variables: Rs, calculated using a site calibration, provided similar results for most gas-phase SVOCs to air concentrations derived using "default" values (commonly accepted Rs). Individual monthly PUF-PAS-derived air concentrations for the majority of the target compounds were significantly different (Wilcoxon signed-rank (WSR) test; p < 0.05) to AAS regardless of the input values (site/sampler based or default) used to calculate them. However, annual average PUF-PAS-derived air concentrations were within the same order of magnitude as AAS measurements except for the particle-phase polycyclic aromatic hydrocarbons (PAHs). Underestimation of PUF-derived air concentrations for particle-phase PAHs was attributed to a potential overestimation of the particle infiltration into the PUF-PAS chamber and underestimation of the particle bound fraction of PAHs.
- MeSH
- kalibrace MeSH
- látky znečišťující vzduch chemie MeSH
- monitorování životního prostředí přístrojové vybavení metody MeSH
- nejistota MeSH
- polyurethany chemie MeSH
- těkavé organické sloučeniny chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
Developments in Food Science,vol.21
448 s.,tab. : Bibliogr.,rejstřík.
The heme-based oxygen sensor histidine kinase AfGcHK is part of a two-component signal transduction system in bacteria. O2 binding to the Fe(II) heme complex of its N-terminal globin domain strongly stimulates autophosphorylation at His183 in its C-terminal kinase domain. The 6-coordinate heme Fe(III)-OH- and -CN- complexes of AfGcHK are also active, but the 5-coordinate heme Fe(II) complex and the heme-free apo-form are inactive. Here, we determined the crystal structures of the isolated dimeric globin domains of the active Fe(III)-CN- and inactive 5-coordinate Fe(II) forms, revealing striking structural differences on the heme-proximal side of the globin domain. Using hydrogen/deuterium exchange coupled with mass spectrometry to characterize the conformations of the active and inactive forms of full-length AfGcHK in solution, we investigated the intramolecular signal transduction mechanisms. Major differences between the active and inactive forms were observed on the heme-proximal side (helix H5), at the dimerization interface (helices H6 and H7 and loop L7) of the globin domain and in the ATP-binding site (helices H9 and H11) of the kinase domain. Moreover, separation of the sensor and kinase domains, which deactivates catalysis, increased the solvent exposure of the globin domain-dimerization interface (helix H6) as well as the flexibility and solvent exposure of helix H11. Together, these results suggest that structural changes at the heme-proximal side, the globin domain-dimerization interface, and the ATP-binding site are important in the signal transduction mechanism of AfGcHK. We conclude that AfGcHK functions as an ensemble of molecules sampling at least two conformational states.
- MeSH
- bakteriální proteiny chemie metabolismus MeSH
- fosforylace MeSH
- hem chemie MeSH
- histidinkinasa chemie metabolismus MeSH
- hmotnostní spektrometrie MeSH
- krystalografie rentgenová MeSH
- kvarterní struktura proteinů MeSH
- kyslík metabolismus MeSH
- molekulární modely MeSH
- Myxococcales metabolismus MeSH
- oxidace-redukce MeSH
- proteinové domény MeSH
- signální transdukce MeSH
- vodík-deuteriová výměna MeSH
- železité sloučeniny chemie MeSH
- železnaté sloučeniny chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
As a promiscuous xenobiotic sensor, pregnane X receptor (PXR) plays a crucial role in drug metabolism. Since dietary phytochemicals exhibit the potential to modulate human PXR, this review aims to summarize the plant-derived PXR modulators, including agonists, partial agonists, and antagonists. The crystal structures of the apo and ligand-bound forms of PXR especially that of PXR complexed with binary mixtures are summarized, in order to provide the structural basis for PXR binding promiscuity and synergistic activation of PXR by composite ligands. Furthermore, this review summarizes the characterized agonists, partial agonists, and antagonists of human PXR from botanical source. Contrary to PXR agonists, there are only a few antagonists obtained from botanical source due to the promiscuity of PXR. It is worth noting that trans-resveratrol and a series of methylindoles have been identified as partial agonists of PXR, both in activating PXR function, but also inhibiting the effect of other PXR agonists. Since antagonizing PXR function plays a crucial role in the prevention of drug-drug interactions and improvement of therapeutic efficacy, further research is necessary to screen more plant-derived PXR antagonists in the future. In summary, this review may contribute to understanding the roles of phytochemicals in food-drug and herb-drug interactions.
- MeSH
- fytonutrienty farmakologie MeSH
- lidé MeSH
- pregnanový X receptor MeSH
- resveratrol MeSH
- steroidní receptory * chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Lead contamination is now widespread, and exposure to lead may cause adverse effects on human beings. In this study, a photoelectrochemical sensor based on flower-like ZnO nanostructures was developed for Pb(2+) detection, using a Pb(2+)-dependent DNAzyme as the recognition unit and a double-strand DNA intercalator, Ru(bpy)2(dppz)(2+) (bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:2',3'-c] phenazine) as the photoelectrochemical signal reporter. The ZnO nanoflower was fabricated on an indium tin oxide (ITO) electrode by the convenient hydrothermal decomposition method. The morphology and photoelectrochemical property of the ZnO nanoflowers were characterized by SEM, XRD and photocurrent measurements. DNAzyme-substrate duplex was assembled on an ITO/ZnO electrode through electrostatic adsorption. In the presence of Pb(2+), RNA-cleavage activity of the DNAzyme was activated and its substrate strand was cleaved, resulting in the release of Ru(bpy)2(dppz)(2+) from the DNA film and the concomitant photocurrent decrease. The detection principle was verified by fluorescence measurements. Under the optimized conditions, a linear relationship between photocurrent and Pb(2+) concentration was obtained over the range of 0.5-20 nM, with a detection limit of 0.1 nM. Interference from other common metal ions was found negligible. Applicability of the sensor was demonstrated by analyzing lead level in human serum and Pb(2+) spiked water samples. This facile and economical sensor system showed high sensitivity and selectivity, thus can be potentially applied for on-site monitoring of lead contaminant.
- MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- chemické látky znečišťující vodu analýza MeSH
- design vybavení MeSH
- DNA katalytická chemie MeSH
- elektrochemické techniky přístrojové vybavení MeSH
- interkalátory chemie MeSH
- jezera analýza MeSH
- limita detekce MeSH
- nanostruktury chemie ultrastruktura MeSH
- olovo analýza MeSH
- oxid zinečnatý chemie MeSH
- pitná voda analýza MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
A surface plasmon resonance (SPR) biosensor for simultaneous detection of multiple organic pollutants exhibiting endocrine-disrupting activity, namely atrazine, benzo[a]pyrene, 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-nonylphenol, is reported. The biosensor utilizes a multichannel SPR sensor based on wavelength modulation of SPR and wavelength division multiplexing (WDM) of sensing channels, antibodies as biorecognition element and a competitive immunoassay detection format. An analysis time of 45 min (including 30-min incubation of the sample with antibodies) and limits of detection as low as 0.05, 0.07, 0.16 and 0.26 ng mL(-1) are demonstrated for benzo[a]pyrene, atrazine, 2,4-D and 4-nonylphenol, respectively. The biosensor is also shown to be regenerable and suitable for repeated use.
- MeSH
- atrazin analýza MeSH
- benzopyren analýza MeSH
- biosenzitivní techniky metody přístrojové vybavení MeSH
- časové faktory MeSH
- endokrinní disruptory analýza MeSH
- fenoly analýza MeSH
- financování organizované MeSH
- imunoanalýza metody MeSH
- kyselina 2,4-dichlorfenoxyoctová analýza MeSH
- povrchová plasmonová rezonance metody přístrojové vybavení MeSH
- senzitivita a specificita MeSH
In Italy a particularly valuable chestnut is "Marrone di Roccadaspide", a protected geographical indication (PGI) product, deriving from a Castanea sativa cultivar, typical of Salerno province in Campania region. As chestnut industrial processes yield a large amount of shell by-products, in this study the possibility to retrain this waste food as potential source of bioactives was investigated. The ability of "Marrone di Roccadaspide" shell MeOH extract to modulate the pro-inflammatory transcriptional factor NF-κB after LPS stimulation, along with the antioxidant activity by a cell-based in vitro test, were evaluated. To correlate the NF-κB inhibition (67.67% at 5 μg/mL) and the strong antioxidant activity to the chemical composition, an analytical approach based on LC-ESI/LTQOrbitrap/MS/MSn along with NMR characterization of isolated compounds was developed. The identification of hydrolysable and condensed tannins, along with flavonoids, phenol glucosides, ellagic acid derivatives, and triterpenoids was accomplished. The most representative compounds were quantitatively analyzed by LC-ESI/QTrap/MS/MS, showing bartogenic acid as the compound occurring in the highest amount (103.08 mg/100 g shells). With the aim to explore the possibility to employ chestnut shells as suitable source of bioactives for the preparation of functional ingredients, the chemical composition and the antioxidant activity of "eco-friendly" extracts (EtOH and EtOH:H2O 7:3) was finally evaluated, showing a high superimposability of the EtOH:H2O (7:3) extract to the MeOH extract.
- MeSH
- antioxidancia analýza MeSH
- Fagaceae chemie MeSH
- fenoly analýza MeSH
- flavonoidy analýza MeSH
- glukosidy analýza MeSH
- hodnotící studie jako téma MeSH
- hydrolyzovatelné taniny analýza MeSH
- kalibrace MeSH
- kyselina ellagová analýza MeSH
- lidé MeSH
- NF-kappa B metabolismus MeSH
- ořechy chemie MeSH
- proantokyanidiny analýza MeSH
- proliferace buněk MeSH
- racionalizace * MeSH
- reaktivní formy kyslíku MeSH
- rostlinné extrakty analýza MeSH
- tandemová hmotnostní spektrometrie MeSH
- taniny analýza MeSH
- triterpeny analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Itálie MeSH