Showing papers in "High Pressure Research in 2009"
TL;DR: The diamond anvil cell has been adapted to a wide variety of analytical techniques that have provided an impressive amount of information about materials at high pressures and high temperatures as mentioned in this paper. But, virtually all of those techniques start with looking into the diamond cell.
Abstract: The year 2008 marked the fiftieth birthday of the diamond anvil cell. Its birth took place when Alvin Van Valkenburg, while working with his colleagues, Charles E. Weir, Ellis R. Lippincott, and Elmer N. Bunting, first realized that he could look right through one of the diamond anvils and see a sample while it was at high pressure. In the following years, these scientists and many others adapted the diamond anvil cell to a wide variety of analytical techniques that have provided an impressive amount of information about materials at high pressures and high temperatures. But, virtually all of those techniques start with looking into the diamond anvil cell.
231 citations
TL;DR: In this article, the structural change in Bi2Te3 under high pressure up to 166 GPa has been studied by powder x-ray diffraction, and two times of phase transitions at room temperature at the pressures of 8 and 14 GPa, respectively, were observed.
Abstract: Structural change in Bi2Te3 under high pressure up to 166 GPa has been studied by powder x-ray diffraction We observed two times of phase transitions at room temperature at the pressures of 8 and 14 GPa, respectively According to our preliminary result on electrical resistance, it is reasonable to suppose that superconducting transition with T c =28 K at the pressures of 102 GPa is observed in phase II On the other hand, we found anomalies of the pressure dependences of lattice parameters and volume at around 2 GPa, which probably means the change in electrical structure on the Fermi surface †This paper was presented at the XLVIth European High Pressure Research Group (EHPRG 46) Meeting, Valencia (Spain), 7–12 September, 2008
64 citations
TL;DR: An improved understanding of the mechanisms of spore inactivation will aid in the food safety assessment of high pressure thermal sterilization in particular, and also assist in the commercialization of this novel process, facilitating adoption by industry.
Abstract: High pressure thermal sterilization is an emerging technology that can produce uniform, minimally processed foods of high quality, better than heat treatment alone. At present, it has not yet been successfully introduced into the food industry, possibly due to the less known inactivation mechanism of high resistant bacterial spores. This study developed and used a new analytical tool to improve the understanding of spore mechanisms at high pressures and temperatures. The generated data were exemplarily incorporated into analyses of industrial sterilization processes. An improved understanding of the mechanisms of spore inactivation will aid in the food safety assessment of high pressure thermal sterilization in particular, and also assist in the commercialization of this novel process, facilitating adoption by industry.
58 citations
TL;DR: In this article, UHPH treatment of fresh apple juice at homogenization pressures from 100 to 300 MPa and inlet temperatures of 4°C or 20°C was shown to decrease microbial counts when treatment pressure reached at least 200 MPa.
Abstract: Ultra-high-pressure homogenization (UHPH) is a technology for continuous treatment of fluid food products and can be applied to avoid thermal treatment of fruit juices. Treatment of fresh apple juice at homogenization pressures from 100 to 300 MPa and inlet temperatures of 4 °C or 20 °C caused important decreases in microbial counts when treatment pressure reached at least 200 MPa. After the treatment, counts were<1 log cfu/ml when homogenization pressure reached at least 200 MPa, and remained stable for more than 2 months at 4 °C. Hydroxymethylfurfural for thermal-treated juice reached values 100-fold higher than for its UHPH-treated or raw counterparts. Browning index was higher in non-thermal-treated juice, and it had an inverse correlation with the severity of UHPH treatment. Part of this browning occurred during Pilot Plant processing, but it kept on browning during preservation in juices in which PPO was not fully inactivated. UHPH treatment of apple juice may be an alternative to conventional therm...
54 citations
TL;DR: In this paper, a successful cell assembly for the differential thermal analysis (DTA) analyses in the cubic press was described, and the results compared favorably with those of the well-known fixed point method, based on pressure-induced phase transitions in bismuth (I-II, 2.55 GPa) and thallium (II-III, 3.68 GPa).
Abstract: Cell pressures in the cubic press have been determined by means of differential thermal analysis (DTA) based on the known fusion curve of aluminum. The results compared favorably with those of the well-known fixed-point method, based on pressure-induced phase transitions in bismuth (I–II, 2.55 GPa) and thallium (II–III, 3.68 GPa). The high-pressure fusion curve of lead was measured using our calibrated results, which agreed well with those of the previous work. All of this was made possible by the development of a successful cell assembly for the DTA analyses in the cubic press. Details of the design are described in the present work.
42 citations
TL;DR: In this article, a new polymorph of Ti2O3 was found at about 19 GPa and 1850 K, and this phase was stable even at about 40 GPa, and the molar volume decreases by 12% across the phase transition at around 20 GPa.
Abstract: The post-corundum phase transition has been investigated in Ti2O3 on the basis of synchrotron X-ray diffraction in a diamond anvil cell and transmission electron microscopy. The new polymorph of Ti2O3 was found at about 19 GPa and 1850 K, and this phase was stable even at about 40 GPa. A new polymorph of Ti2O3 can be indexed on a Pnma orthorhombic cell, and the unit-cell parameters are a=7.6965 (19) A, b=2.8009 (9) A, c=7.9300 (23) A, V=170.95 (15) A3 at 19 GPa, and a=7.8240 (2) A, b=2.8502 (1) A, c=8.1209 (3) A, V=181.10 (1) A3 at ambient conditions. The Birch–Murnaghan equation of state yields K 0=206 (3) GPa and K′0=4 (fixed) for corundum phase, and K 0=296 (4) GPa and K′0=4 (fixed) for the post-corundum phase. The molar volume decreases by 12% across the phase transition at around 20 GPa. The structural identification was carried out on a recovered sample by the Rietveld method, and a new polymorph of Ti2O3 can be identified as Th2S3-type rather than U2S3-type structure. The transition from corundum-t...
34 citations
TL;DR: In this paper, pressure-induced solidification of 4:1 methanol-ethanol at 50°C and 100°C was investigated using the ruby fluorescence technique and an externally heated diamond anvil cell.
Abstract: We have investigated the pressure-induced solidification of 4:1 methanol–ethanol at 50 °C and 100 °C, using the ruby fluorescence technique and an externally heated diamond anvil cell. The hydrostatic limits of this pressure transmitting medium increases at a rate of 1 GPa per 11 °C to reach 17 GPa at 100 °C. This demonstrates that the hydrostatic limits can be considerably increased by modest heating.
31 citations
TL;DR: In this article, the volumetric properties of sunflower and olive oils were determined to generate an original data set, and an empirical equation of state was developed to derive the isothermal compressibility and thermal expansivity.
Abstract: Numeric simulation is used to optimise the high pressure processing of foods. It allows for heat and mass transfer modelling and thus to address process uniformity problems. This modelling involves adiabatic heat, experimentally known to be higher for fats than for water, but hardly calculable due to the lack of data on food properties under pressure. In this work, the volumetric properties of sunflower and olive oils were determined to generate an original data set. A volumetric device working up to 350 MPa was assembled on the plug of high hydrostatic pressure equipment. The specific volume was measured as a function of pressure and temperature. An empirical equation of state was developed to derive the isothermal compressibility and thermal expansivity. Comparison with water properties shows how these results should contribute to improve the predictive skills of models used to simulate high pressure treatments of fat rich foods.
31 citations
TL;DR: In this article, the influence of high-pressure treatment on the structure and allergenicity of the recombinant main apple allerogen, rMal d1, on apple juice and homogenates prepared from the Golden Delicious variety was studied.
Abstract: The aim of this paper is to study the influence of high-pressure treatment (HPT) on the structure and allergenicity of the recombinant main apple allergen, rMal d1, on apple juice and homogenates prepared from the Golden Delicious variety. In vitro and in vivo tests have been used for evaluation of HPT effects: circular dichroismus (CD) electron spectroscopy, the basophile activation test (BAT-CD63 expression), the Western blot (WB) with immunoglobulin E-positive serum, and the skin prick-to-prick test (PTP). Apple homogenates were tested using a double-blind placebo-controlled food challenge (DBPCFC). rMal d1 solutions treated at 500 MPa for 10 min at 30 °C showed the greatest changes in CD spectra when compared with the untreated samples. The WB test of these solutions showed that HPT did not influence allergic reactions. The BAT also failed to differentiate between HP-treated and -untreated rMal d1 solutions. Apple juice treated with HPT in the range of 450–550 MPa for 3 and 10 min at 30 °C failed to s...
24 citations
TL;DR: In this paper, a single crystal of BiMnO3 oxide was grown at high pressure-high temperature (HP-HT) in a belt system using a flux method based on H3BO3.
Abstract: In the literature, the properties of the multiferroic BiMnO3 oxide have been studied in polycrystalline and thin film materials Here, we report the first study performed on a single crystal of BiMnO3 The single crystals were grown at high pressure–high temperature (HP–HT) in a belt system using a flux method based on H3BO3 For the first time, we have measured the Raman spectrum of BiMnO3 and solved its crystallographic structure based on the data collected by X-ray diffraction (XRD) on a single crystal In addition, we have studied in situ the HP–HT synthesis of polycrystalline BiMnO3 by XRD Starting from a mixture of Bi2O3 and Mn2O3, an intermediate phase has been found before the formation of the distorted perovskite BiMnO3
24 citations
TL;DR: In this article, the effect of isostatic pressure 500 MPa on tryptic and chymotryptic hydrolysis of α- and β-casein, bovine serum albumin (BSA), β-lactoglobulin (β-Lg) and α -lactalbumin (α-La).
Abstract: This work describes the effect of isostatic pressure 500 MPa on tryptic and chymotryptic hydrolysis of α- and β-casein, bovine serum albumin (BSA), β-lactoglobulin (β-Lg) and α -lactalbumin (α-La). Digestion was also conducted at atmospheric pressure. The extent of hydrolysis and peptide profiles were analysed by gel-permeation and reverse-phase high-performance liquid chromatographies. The residual immunochemical reactivities of the protein hydrolysates were assessed by the Streptavidin ImmunoCAP system (Phadia) for determination of specific immunoglobulin type E (IgE) antibodies. We have found very significant changes of the peptide profiles and a progressive reduction in residual-intact proteins after applying high pressure during tryptic proteolysis of β-Lg and BSA and chymotryptic proteolysis of β-Lg, α-La and BSA. A statistically significant decrease of the residual immunochemical reactivities of β-Lg tryptic and α-La chymotryptic hydrolysates prepared under high pressure, in comparison with the con...
TL;DR: In this paper, a series of ferrite spinels MFe2O4 (Mg, Co, Zn) up to ∼ 70 GPa using diamond anvil cells were used as pressure media, resulting in a high quality fit to both second-and third-order equations of state (EOSs).
Abstract: High-pressure synchrotron X-ray diffraction studies were carried out on a series of ferrite spinels MFe2O4 (M=Mg, Co, Zn) up to ∼ 70 GPa using diamond anvil cells. He and Ne, used as pressure media, provided quasi-hydrostatic conditions, resulting in a high-quality fit to both second- and third-order equations of state (EOSs). A quality fit to the second-order EOS allows a comparison between the compressibility of these spinels and that of other spinels found in the literature. Fitting to the second-order Birch–Murnaghan EOS results in the values of K 0=170.5(8), 176.1(6) and 174(2) GPa for M=Mg, Co and Zn, respectively. A linear dependence of K 0 is obtained as a function of the normalized average cationic-sphere volume S N of each spinel with a slope of 490(15) GPa/A3. A number of previous studies of the same and similar spinels exhibit a strong deviation from K 0(S N), which can be attributed to a lack of hydrostatic conditions.
TL;DR: The inactivation kinetics of high hydrostatic pressure for Salmonella typhimurium inoculated in tryptone soy broth and foods were studied and showed two-phase inactivation (fast to slow) and the use of inactivation could be beneficial to the food industry for optimizing process conditions.
Abstract: The inactivation kinetics of high hydrostatic pressure for Salmonella typhimurium (KUEN 137) inoculated in tryptone soy broth (TSB) and foods (raw milk and orange juice) were studied from 250 to 400 MPa, 15–45 °C and pH adjusted from 5.0 to 7.0. The rate of inactivation of S. typhimurium during the initial 10 min was far greater than during the remaining treatment time. The inactivation of S. typhimurium showed two-phase inactivation (fast to slow). Decimal reduction times (D value) for S. typhimurium in the second phase were 4.61, 2.59, 2.09, and 1.80 min at 250, 300, 350, and 450 MPa, respectively, in TSB after 10 min (second phase). D values were 1.75 and 1.50 min for S. typhimurium in milk and orange juice, respectively, at 300 MPa (second phase) and the k values were 1.32 and 1.54 min−1, respectively (second phase). The rate of inactivation increased in increasing temperature and there were significant (P<0.05) reductions in the S. typhimurium at treated temperatures, pressures, and pH. The use of in...
TL;DR: In this article, pressure-induced amorphization phenomenon in superconducting compound FeSe0.5Te0.4 tetrahedra under compression is attributed to a kinetic hindrance to a stable phase.
Abstract: We report pressure-induced amorphization phenomenon in a superconducting compound FeSe0.5Te0.5 to a pressure of 27 GPa in a diamond anvil cell. The synchrotron x-ray diffraction studies reveal that the ambient pressure tetragonal phase (space group P4/nmm) transforms to an amorphous phase at 11.5 GPa during compression and reverts back to the tetragonal phase during decompression at 2.8 GPa. The measured equation of state for the tetragonal phase and the amorphous phase is presented. The disordering of Fe(SeTe)4 tetrahedra under compression is attributed to a kinetic hindrance to a stable phase and is likely to impact its superconducting properties under high pressures.
TL;DR: In this paper, the optical reflectivity for a uniaxially strained graphene single layer between a SiO2 substrate and air was evaluated and a tight binding model for the band dispersion of graphene was employed.
Abstract: We evaluate the optical reflectivity for a uniaxially strained graphene single layer between a SiO2 substrate and air. A tight binding model for the band dispersion of graphene is employed. As a function of strain modulus and direction, graphene may traverse one of several electronic topological transitions, characterized by a change of topology of its Fermi line. This results in features in the conductivity within the optical range, which might be observable experimentally.
TL;DR: In this article, the authors present technical developments which now allow accurate single-crystal studies up to 10 GPa and at temperatures down to 10 K using time-of-flight Laue diffraction and the Paris-Edinburgh press.
Abstract: Single-crystal diffraction techniques offer significant advantages over powder diffraction methods, but until recently high-resolution neutron single-crystal studies at high pressure have been restricted to pressures below 2 GPa. We present technical developments which now allow accurate single-crystal studies up to 10 GPa and at temperatures down to 10 K using time-of-flight Laue diffraction and the Paris-Edinburgh press. Prospects for work above 10 GPa are discussed, and some data from a successful test at 12 GPa are shown.
TL;DR: In this article, structural, elastic, thermodynamic (Debye temperature and melting temperature), and lattice dynamical (phonon dispersion curves, heat capacity, and entropy) properties of CaX via ab initio calculations within the local density approximations.
Abstract: We have studied structural, elastic, thermodynamic (Debye temperature and melting temperature), and lattice dynamical (phonon dispersion curves, heat capacity, and entropy) properties of CaX via ab initio calculations within the local density approximations. The results are compared with the available experimental and other theoretical data, and the agreement is, generally, quite good. We also predict the temperature and/or pressure-dependent behaviors of some mechanical, lattice dynamical, and thermodynamic properties for the same compounds.
TL;DR: In this paper, the authors have performed finite-element simulations to study the performance and the shear stress distribution of WC anvils used in the China-type cubic-anvil high pressure apparatus (SPD-6×2000).
Abstract: Stress distribution in cemented tungsten carbide (WC) anvils is of primary interest in high pressure research, but is very difficult to determine experimentally. We have performed finite-element simulations to study the performance and the shear stress distribution of WC anvils used in the China-type cubic-anvil high pressure apparatus (SPD-6×2000). Our results show that in order to avoid failure cracks in high-stress areas, the maximum shear stress should be lower than 3.17 GPa for the WC anvils (8% cobalt). The simulations have been verified by high-pressure experiments. Our method of analyzing stress distribution helps in evaluating the ability of WC anvils, and would aid in designing a new anvil to enhance performance.
TL;DR: In this article, the effect of high pressure and strong external magnetic fields on the photoluminescence properties of single-crystal thin films of well-oriented $KY(WO_4)_2$ at low temperatures was investigated.
Abstract: In this paper, we present the preliminary results of the combined effect of high pressure (up to 7.5 GPa) and strong external magnetic fields (up to 28.5 T) on the photoluminescence (PL) properties of $Er^{3+}–Yb^{3+}$ co-doped single-crystal thin films of well-oriented $KY(WO_4)_2$ at low temperatures. Measurements were carried out under pulsed magnetic field, exciting the $Er^{3+}$ ions via upconversion mechanisms by a Ti:sapphire laser with the external magnetic field applied along the crystallographic b axis. The detailed study of the green $^{4}S_3/_2 - ^{4}I_1_5/_2 Er^{3+}$ PL after infrared excitation around 1μm as a function of pressure and external magnetic field reveals the potential applicability of this system as sensor of high magnetic fields, high pressure and low temperature, simultaneously.
TL;DR: The structural stability of marcasite-type FeP2 at high pressure has been studied by X-ray diffraction, Raman spectroscopy, and theoretical calculations as mentioned in this paper.
Abstract: The structural stability of marcasite-type FeP2 at high pressure has been studied by X-ray diffraction, Raman spectroscopy, and theoretical calculations. Experimental results show that no phase transitions happen up to 28 GPa at room temperature. The shortest axis of the marcasite-type FeP2 cell, the c-axis, is the most compressible, due to the softening of edge-shared octahedra along the c-axis. The linear pressure coefficients and Gruneisen parameters of four Raman modes are determined. Theoretical calculations further support the experimental results and indicate that FeP2 is still a semiconductor up to 35 GPa.
TL;DR: In this article, it was shown that ADH can exist at room temperature in the substitutionally disordered structure of the ammonia monohydrate (AMH) phase VI, which implies that a solid solution may exist between ADH and AMH at high pressure, and this is of probable importance to models of the outer solar system.
Abstract: Ammonia dihydrate (ADH) is an important constituent of the outer solar system and its high-pressure behaviour is relevant to the modelling of Titan, Uranus and Neptune. Our neutron diffraction studies show that ADH can exist at room temperature in the substitutionally disordered structure of the ammonia monohydrate (AMH) phase VI. This implies that a solid solution may exist between ADH and AMH at high pressure, and this is of probable importance to models of the outer solar system.
TL;DR: Composite diamond anvils have been developed for high-pressure/high-temperature measurements as mentioned in this paper, which are fabricated using single-crystal chemical vapor deposition (CVD) from previously used and/or damaged anvil made of natural or synthetic diamond.
Abstract: Composite diamond anvils have been developed for high-pressure/high-temperature measurements of diamond anvil cells. The anvils are fabricated using single-crystal chemical vapor deposition (CVD) from previously used and/or slightly damaged anvils made of natural or synthetic diamond. These composite anvils can be fabricated to possess optical characteristics at least comparable to conventional diamond anvils, whereas the single-crystal CVD portion is more durable because of its enhanced toughness relative to natural diamond. The viability of such anvils is demonstrated in measurements on hydrogen at megabar pressures and high temperature.
TL;DR: In this article, the implementation of a heating element to a composite gasket for high-temperature applications in the diamond-anvil cell was developed based on a double-gasket assemblage.
Abstract: The implementation of a heating element to a composite gasket for high-temperature applications in the diamond-anvil cell was developed based on a double-gasket assemblage. The heating element is a thin platinum wall that covers the central borehole of the metal–ceramic–metal composite gasket and interconnects the two metal component parts of the gasket. Applying electric powers up to 35 W to the two gasket metal components result in ring-like heating around the sample inside the pressure chamber with temperatures exceeding ∼2000 K in individual cases. The ring-like distribution of the maximum temperature located at the pressure-chamber wall facilitates a homogeneous temperature distribution at the sample position. As a consequence of the concentration of the heating power to the pressure chamber region, gradients of surface temperatures, both at the gasket and the diamond anvil, appear to be more pronounced compared with those known for classical external electrical heating. Apart from the tests of the m...
TL;DR: The V7 Paris-Edinburgh press was used in this article for torsional testing of polycrystalline Zr material at pressures up to 7 GPa (extendable to 15 GPa).
Abstract: We describe a new device, based on a V7 Paris–Edinburgh press, for torsional testing of material at pressures up to 7 GPa (extendable to 15 GPa). Samples are deformed using a simple shear geometry between opposed anvils by rotating the lower anvil, via a rotational actuator, with respect to an upper, stationary, anvil. Use of conical anvil profiles greatly increases sample dimensions more than other high-pressure torsional apparatus did. Samples of polycrystalline Zr (2 mm thick, 3.5 mm diameter) have been sheared at strains exceeding γ ∼1.5 at constant strain rate and at pressures from 1.8 to 5 GPa, and textural development has been studied by electron microscopy. Use of amorphous-boron-epoxy gaskets means that nearly simple shear of samples can be routinely achieved. This apparatus allows study of the plastic and anelastic behaviour of materials under high pressure, and is particularly suited for performing in situ investigations using synchrotron or neutron radiation.
TL;DR: In this article, the structural changes and allergenicity of recombinant main celery (RApi g1) proteins caused by high pressure were studied by using circular dichroismus (CD) spectra.
Abstract: The structural changes and allergenicity of recombinant main celery allergen rApi g1 caused by the high pressure were studied. We have treated the buffer solutions of rApi g1 by high pressure at 500 MPa for pressure holding times 10 and 20 min and holding time temperatures 30 °C, 40 °C and 50 °C. The structural changes were studied by circular dichroismus (CD) spectra. The allergenic reaction of the rApi g1 was tested by Western blot analysis. The greatest changes of the structure were found at samples treated by 500 MPa at 50 °C. The samples treated at this temperature at pressure levels 400, 450 and 500 MPa and held for 10 and 20 min showed that protein structure changes are positively correlated with pressure. Western blot analysis evidenced that a pressure of 500 MPa held for 10–20 min at temperatures 30–50 °C did not change the allergenicity of the rApi g1 protein when compared with the untreated sample.
TL;DR: The perovskites ACr(IV)O3 (A=Sr, Ca, Pb) have been synthesized at high pressure and temperature and their microstructure and properties are discussed in this paper.
Abstract: The ‘simple’ perovskites ACr(IV)O3 (A=Sr, Ca, Pb) have been synthesized at high pressure and temperature. Their microstructure and properties are discussed. Specific heat and susceptibility measurements indicate an antiferromagnetic ordering at low temperature in CaCrO3, which is confirmed to be of the C-type by neutron diffraction. †This paper was presented at the XLVIth European High Pressure Research Group (EHPRG 46) Meeting, Valencia (Spain), 7–12 September, 2008.
TL;DR: In this paper, the authors describe techniques for the growth of single crystals in situ at high pressure from the melt, suitable for high-resolution neutron diffraction experiments, and present results from a low-temperature test study of ice VI.
Abstract: We describe techniques for the growth of single crystals in situ at high pressure from the melt, suitable for high-resolution neutron diffraction experiments, and we present results from a low-temperature test study of ice VI. We also outline the developments we are making to increase the pressure at which we can grow samples of this kind and to improve further the quality of the data collected.
TL;DR: In this paper, the influence of shock-wave pressure treatment up to 65 GPa on the crystal structure and the superconducting transition temperature of a polycrystalline MgB2 sample has been investigated.
Abstract: The influence of shock-wave pressure treatment up to 65 GPa on the crystal structure and the superconducting transition temperature of a polycrystalline MgB2 sample has been investigated. X-ray diffraction measurements have revealed that the shock-wave pressure does not result in any irreversible structural phase transitions in the MgB2, except for microdistortions formed in the crystal structure of the shock-wave pressure-treated MgB2 sample. This conclusion is in agreement with the results of superconducting transition temperature measurements of a MgB2 sample performed before and after its shock-wave pressure treatment.
TL;DR: In this article, the Tait coefficients for the pressure above the phase transition suggest that the high-pressure phase is solidified, and the modified Tait equation coefficients were evaluated for rapeseed oil, soy oil, sunflower oil and linseed oil.
Abstract: The paper presents compressibility studies of some vegetable oils within the range of 1 GPa. The measurements of the volume were done for rapeseed oil, soy oil, sunflower oil and linseed oil at constant temperature. On this basis, the modified Tait equation coefficients were evaluated. In the case of rapeseed oil, soy oil and sunflower oil, the discontinuity of P–V characteristics for phase transition has been observed. The value of Tait coefficients for the pressure above the phase transition suggests that the high-pressure phase is solidified. The experiment was conducted with a computer-based data acquisition system with software written in National Instruments LabVIEW™ graphical programming language. Piston displacement was measured by electronic digital calliper with RS232 interface.
TL;DR: In this article, the influence of high-pressure treatment (HPT) on the allergenicity of rDau c1 and carrot juice using in vitro and in vivo tests was detected.
Abstract: The aim of our study was to detect the influence of high-pressure treatment (HPT) on the allergenicity of recombinant allergen rDau c1 and carrot juice using in vitro and in vivo tests. The buffer solution of recombinant main carrot allergen rDau c1 for the basophil activation test (BAT) and Western blot (WB) was used. Dau c1 was pre-treated by pressure 500 MPa for 10 min and different temperatures (30 °C, 40 °C, 50 °C) and pressure from 400 to 550 MPa for 3 and 10 min. Neither the HPT from 400 to 550 MPa for 3 and 10 min nor the HPT at 500 MPa for 10 min and temperatures 30 °C, 40 °C, and 50 °C had the influence on basophil activation by rDau c1. Serum samples of birch pollen allergic patients reacted in WB with solution of rDau c1 treated by HP 500 MPa for 10 min at temperature 30 °C, 40 °C, and 50 °C. This pressure procedure did not influence the immune reactivity of rDau c1 in WB test. The structural changes of rDau c1 caused by HPT studied by circular dichroismus spectra were found. Mild increase of ...