In vitro availability of minerals from oat products

The content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals. © 2002 Society of Chemical Industry     

The application of d-SPE in the QuEChERS method for the determination of PAHs in food of animal origin with GC–MS detection

This paper reports the evaluation of the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the determination of polycyclic aromatic hydrocarbons (PAHs) in food of animal origin with GC–MS detection. Although in the available literature, there is a lot of information about sample preparation method for PAHs determination in food samples, but the QuEChERS method application for PAHs determination in food of animal origin has not been reported as yet. The results showed that the best recovery ratios 72.4–110.8 % with relative standard deviation lower than 10 % for all determined compounds were received for the method with ethyl acetate as an extraction solvent, primary–secondary amine and C₁₈ sorbents and evaporation to dryness and dissolving the residues in the hexane. The limit of quantification ranged from 0.0003 to 0.0030 mg kg^?1 for pyrene and benzo[a]anthracene, respectively. This method was also used for the determination of PAHs in 15 samples of pork ham. In 8 of 15 samples selected, PAHs were identified. It was observed that in 6 cooked ham and one smoked and cooked samples, any PAHs were found. In other samples, which were smoked and roasted, some low concentration of PAHs was detected. In one sample benzo[a]pyrene (0.0015 mg kg^?1), in one sample benzo[b]fluoranthene (0.0015 mg kg^?1) and in one sample chrysene (0.0024 mg kg^?1) were detected. A number of other less harmful PAHs were also determined. There were no exceedances of maximum levels (according to Commission Regulation (EU) No 835/2011) for determined PAHs in any of the analysed samples.     

Photochemical behaviour of hydrolysed keratin

An investigation into the influence of UV irradiation on keratin hydrolysates was carried out using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. It was found that the absorption of keratin hydrolysates in solution increased during irradiation of the sample, most notably between 250-280 and 320-410 nm. The increase in absorbance in the region 320-410 was because of the new photoproducts formed during UV irradiation of keratin hydrolysates. The fluorescence of keratin hydrolysates was observed at 328 nm after excitation at 270 nm. UV irradiation caused fluorescence fading at 328 nm, and after 60 min of irradiation, a new broad weak band of fluorescence, attributable to new photoproducts, emerged in the UV wavelength region with emission maximum between 400 and 500 nm. FTIR spectroscopy results showed degradation of keratin under UV irradiation. A slight increase in oxidized sulphur species was also observed. The results obtained suggest that UV irradiation can be used as modifying agent for preparation of keratin hydrolysates for cosmetic applications.     

The effect of halloysite additive on operation of boilers firing agricultural biomass

The paper presents results of investigations on using halloysite as an additive in biomass-fired boilers. It has been shown that in the case of a few different agricultural biomasses the halloysite addition increased the ash sintering temperature to the values noted for coals. This is an effect of bonding sodium and potassium in the form of chlorides and other compounds. In practical terms the halloysite additive may reduce slagging and fouling of boiler heating surfaces as well as deteriorate the agglomeration processes in fluidized beds. Moreover, addition of halloysite reduces the amount of KCl and NaCl present in ash (and therefore in ash deposits) thus decreasing the rate of high temperature corrosion.     

SBA-15 mesoporous silica modified with rhodium by MDD method and its catalytic role for N<Subscript>2</Subscript>O decomposition reaction

SBA-15 mesoporous silicas modified with rhodium were studied as catalysts for the N₂O decomposition reaction. Rhodium was deposited on SBA-15 by the Molecular Designed Dispersion (MDD) method using Rh(acac)₃ as a precursor of active phase. The same method was used for the deposition of Cu, Fe, Al and Ti. The SBA-15 support modified with metals were characterized with respect to metal loading (EPMA), structure (XRD), texture (BET), morphology (SEM), Rh dispersion (oxygen chemisorption), surface acidity (pyridine adsorption) and chemical nature of introduced copper and iron species (UV–vis-DRS). The rhodium-containing SBA-15 samples were found to be active catalysts for the N₂O decomposition reaction. Deposition of Al on the Rh-loaded catalyst increased its activity. An opposite effect was observed for the samples modified with Cu and Fe.     

Biodegradable polyurethane composite scaffolds containing Bioglass® for bone tissue engineering

Five types of solid and porous polyurethane composites containing 5–20 wt.% of Bioglass® inclusions were synthesized. Porous structures were fabricated by polymer coagulation combined with the salt-particle leaching method. In-vitro bioactivity tests in simulated body fluid (SBF) were carried out and the marker of bioactivity, e.g. formation of surface hydroxyapatite or calcium phosphate layers upon immersion in SBF, was investigated. The chemical and physical properties of the solid and porous composites before and after immersion in SBF were evaluated using different techniques: Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). Moreover the surface structure and microstructure of the composites was characterised by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), respectively. Mercury intrusion porosimetry, SEM and microtomography (μCT) were used to determine pore size distribution and porosity. The fabricated foams exhibited porosity >70% with open pores of 100–400 μm in size and pore walls containing numerous micropores of <10 μm. This pore structure satisfies the requirements for bone tissue engineering applications. The effects of Bioglass® addition on microstructure, mechanical properties and bioactivity of polyurethane scaffolds were evaluated. It was found that composite foams showed a higher storage modulus than neat polyurethane foams. The high bioactivity of composite scaffolds was confirmed by the rapid formation of hydroxyapatite on the foam surfaces upon immersion in SBF.     

Density and surface tension of the Pb-Sn liquid alloys

The maximum bubble pressure method and the dilatometric method were used, respectively, in measurements of surface tensions and densities of Pb-Sn liquid alloys. The experiments were carried out in the temperature range from 573 to 1200 K for the pure Pb, pure Sn, and 7 alloys of the compositions 0.1, 0.2, 0.26, 0.36, 0.5, 0.7, and 0.9 mole fraction of Pb. A straight-line dependence on temperature was observed and fitted by the method of least squares both for the densities and the surface tensions. The calculated density isotherm at 673 K showed a positive deviation from the linearity over the entire range of composition, and the same tendency was seen at 1173 K for compositions higher than X _Pb=0.26. At the lower concentration of Pb, a nearly linear character of 1173 K isotherm was noted. In the case of surface tensions, both at the lowest and the highest temperatures (673 and 1173 K), the deviation from linearity with composition was negative, but deviation decreased with increasing temperature. The isotherms of the compositional dependence of surface tension calculated from the Butler model exhibit good agreement with experimental data.     

Numerical analysis of methane migration from floor strata to a longwall face

A two-dimensional numerical model of a large (1 000 m×200 m) section ofmine strata in the vicinity of seam 349 in Iongwali panel 802 in part B of the Murcki Collieryin the Upper Silesian Coal Basin,Poland,was built using the Universal Distinct ElementCode UDEC.Longwall extraction of seam 349 with roof caving was simulated in the modelover a length of 450 m.Mining-induced changes in displacements,strains and stresses inthe mine strata were investigated.Under the assumptions that (1) methane.bearing strat...     

Impact of the addition of dolomite to cream-firing clays on the technological and color properties of sintered ceramics

Sintered ceramics, represented by ceramic tiles or clinker bricks, are widely used in the building materials industry due to their technological properties and visual qualities. The topic of color changing of ceramic materials from cream-firing clays with the use of mineral additives has not been addressed to date. The aim of the paper was to investigate the effect of granulation of dolomite additives to ceramic masses based on cream-firing Borkowice clay on the color and properties of fired ceramic materials. The paper proposes that grain size of mineral additive affects the color of sintered ceramics. In order to confirm this hypothesis, a number of experiments were performed, consisting of determination of the color and technological properties of ceramic materials. The conducted tests showed that the color and technological properties of sintered ceramics are influenced by the grain size of the additives used.