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  • Author or Editor: L. Nagy x
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Vitamin D2 is essential for the human body and mushrooms are proved to be one of the best sources of it. In our experiment biologically active, pre-harvest white and cream type button mushrooms and oyster mushroom were treated with UVB light in order to increase their vitamin D2 level, by transforming their natural ergosterol content into vitamin D2. UVB lamps (operating on 312 nm) and six time periods of irradiation (15 to 90 min) were used. After three consecutive days of treatments the yield were measured and samples were taken for vitamin D2 analysis. Data showed considerable increase in vitamin D2 levels at every time period in each cultivar.

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Our experiments were based on a model solution containing five of the main pineapple aroma components. Both sweeping-gas pervaporation and vacuum-pervaporation methods were carried out. Measurements were performed at different temperatures and feed flow rates. The purposes of this study were to examine applicability of the two pervaporation methods in reference to the pineapple aroma recovery, the effects of the operating parameters on the process, and modelling the pervaporation process by resistance-in-series model. Higher enrichment could be reached with vacuum-pervaporation than the sweeping-gas method. The separation process is determined by the diffusion of compounds in the membrane, thus the resistance in the boundary layer at liquid side is negligible. Based on performed experiments, the pervaporation process can be applied in beverage industry for aroma recovery.

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Acta Alimentaria
Authors: L. Szalóki-Dorkó, A. Nagy, N. Adányi and R. Tömösközi-Farkas
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Development of rapid methods is often needed for the in-line process control of the proximate composition (e.g. fat or moisture content) of meat in the meat processing plants. This paper reports on the continuous wave nuclear magnetic resonance (CW-NMR) technique applied for determining fat content in fresh meat. The interfering moisture content in meat was removed by microwave drying and the dried residue was transferred quantitatively into the NMR-tubes. The total analysis time was about 35 min. Experiments were performed with pork (with a fat content from 1.7% to 21%), beef (with a fat content from 1.0% to 16.1%), lard (rendered pork fat) and tallow (rendered beef fat) samples and with their combinations: lard-tallow, lard-lean pork, tallow-lean beef and lard-tallow-lean beef-lean pork. The regression (prediction) equations (NMR-signal vs. fat content determined with the Soxhlet reference method) of pork and beef did not differ significantly. However, there was a noticeable difference between the regression lines of pure lard and pure tallow. Moreover, the latter ones differed from the regression equations of pork, beef and of the various meat-fat combinations. The variability of the fatty acid composition of the fat also seems to influence the stability of the calibration curves, because the sensitivity of the CW-NMR signal to the fatty acid composition interferes with the quantitative determination of fat content in meat.

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In recent years, research related to studying the effect of gut microflora on the human health has become of major economic importance. The main objective of our study was to examine whether or not the orally administered Lactobacillusstrains (LB) as an oral adjuvant can improve the mucosal immune protectionviaan enhanced IgA secretion to a co-administered marker antigen ovalbumin (OVA). We adapted a murine (BALB/c) model to demonstrate beneficial adjuvant effects of probiotic LB strains. Orally sensitised mice with OVA, which were prefed with native or heat denatured (HD) Lactobacillus salivarius (Ls) or Lactobacillus casei (Lc) responded better or with the same efficiency to a vaccination with antigen (OVA) than mice that had been sensitised only with OVA or not sensitised at all. Antibody (IgA) responses in the gut were increased in response to vaccination with OVA in mice that had been prefed with native or heat denatured Ls or Lc followed by Ls or Lc and OVA feeding. In prefed groups, the OVA feeding alone primed for specific immune response, while adjuvanted OVA has increased the immune exclusion potential of the gut.

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Water and pollution transport takes places in fissures, and fissures may also reduce the stability of the rock body. Therefore, fissures in rock are an important issue, especially in case of multi-directional fissure systems, where the situation is more complicated.The so-called azimuthal technique, by using the Schlumberger array is a routinely applied method in geoelectric fissure detections. As we demonstrate it by using analogue model measurements, this method has several shortages. In absence of a priori information, the fissure directions could be obtained only in 60% of the total cases with a precision of ±10%. We have also demonstrated that the effectivity of the method becomes even worse, when the covering sediment layer is thicker. At the same time, when we simply rejected the anisotropy paradox, it was found, that the effectivity of the method is increasing with increasing sediment thickness. The original azimuthal technique is based on the generally accepted hypothesis of the so-called geoelectric anisotropy paradox. The analogue modelling results have made clear that the critical point of the method is the application of the anisotropy paradox. The fissure directions can only be determined, if the conditions of the anisotropy paradox are clearly defined. However, having more than one fissure directions, statistically these fissure directions can be correctly determined.

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Abstract  

Studies were initiated to investigate the effect of the delivery mode of45Ca ions through guinea pig skin in vivo. Direct current (DC), pulsating current (PC) and a Bernard current form, the “courtes periodes” current profile (CP) were applied with the same current density (0.16 mA/cm2) and for the same duration (30 minutes). The45Ca ions were delivered from a Ca-bentonite patch radiolabeled with45Ca (a natural mineral clay rich in calcium, 50 mgCa/g). The total quantity of applied bentonite was 1.5g×10 days=15g.45Ca was counted in different biological samples of the animals. The delivery of45Ca ions into the body (systemic effect) is the highest when CP current is applied (6.87±0.95·10−12g/samples). The local effect appears to be more effective in case of DC current mode (5.89±0.12·10−12g/0.5g bone). Total calcium measurements proved that the result of transdermal radiocalcium delivery is not only an ion exchange process at the surface of the bone but a deposition of calcium ions into the hydroxiapatite matrix (the net calcium introduction, which represent the difference between the total calcium into the treated bone and total calcium into untreated bone varied from 15.52±2.42·10−3g/0.5g bone to 44.30±3.50·10−3g/0.5g bone). The results suggest that iontophoresis could be used to accumulate calcium into different target tissues using the appropriate current system.

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Abstract  

Eight di-n-butyltin(IV) complexes with glycolic, 2-hydroxy-propionic, succinic and malic acids, have been prepared by two different procedures. The compounds were characterised by elemental analysis, FTIR, Raman and119Sn Mössbauer spectroscopy. The IR and Raman data indicated the presence of bidentate and/or monodentate carboxylate groups, non linear C−Sn−C bonds, and Sn−O bonds within the complexes. The results of Mössbauer spectroscopic measurements, based on point-charge model calculations, have shown the occurrence of trigonal bipyramidal environment in the central tin(IV) atom, besides the octahedral and tetrahedral structure.

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Nuclear inelastic resonant scattering of synchrotron radiation was applied to the study solutions of 57Fe complexes. In order to reveal different inelastic contributions solutions of two different 57Fe complexes of different molecular dimensions with solvents of substantially different viscosities were studied. We argue that the only former experiment available in the literature overestimates the role of the diffusivity in affecting the spectrum. The first direct observation of an intramolecular vibrational transition assisting the nuclear resonance absorption in a liquid is reported.

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Periodica Mathematica Hungarica
Authors: B. Sz.-Nagy, A. Lee, L. Gehér and A. Bosznay

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