HPLC-fluorescence analysis of polycyclic aromatic hydrocarbons (PAHs) in pork meat and its gravy fried without additives and in the presence of onion and garlic

The effect of onion and garlic on the formation of polycyclic aromatic hydrocarbons (PAHs) was evaluated by comparing the concentrations of PAHs in meat and gravy samples coming from pork dishes prepared in the presence and absence of these spices. PAHs were analysed by high performance liquid chromatography with fluorescence detection. The clean-up procedure included alkaline hydrolysis, solid-phase extraction (on columns with diatomaceous earth and propyl sulphonic acid) and column chromatography on silica gel. Total concentrations of 6 PAHs (benzo[b]fluoranthne, benzo[k]fluoranthne, benzo[a]anthracene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene) were (in ng g⁻¹ of cooked meat) from 2.0 to 7.2 in meat samples and from 0.05 to 0.6 in gravies. Concentration of B[a]P was from 0.38 to 1.61 in meat and from 0.01 to 0.11 in gravy samples. Onion (30/100 g of meat) caused on average decrease of 60% of the total content of PAHs in pan fried meat and of over 90% in gravies. Garlic (15/100 g of meat) lowered the concentration of 54% in meat on average and from 13.5–79% in gravies.     

The quality of pork and the shelf life of the chosen carcass elements during storage depending on the method of carcass chilling

The aim of this study was to analyze the influence of the chilling method on meat quality and the microbiological durability of pork cuts during storage. The left half‐carcasses were put through the shock tunnel and the right half‐carcasses were placed directly in the chilling room. After chilling, pH measurements were taken in two muscles. The carcasses were cut, and drip loss, marbling, and color of LL muscle were estimated. The microbiological quality of meat elements was estimated according to the procedure included in the EC regulation. The total viable count tests were done after chilling, 8, 12, 14, 16, and 18 days of storing. The drip loss was higher in the group that was chilled slower. In the group of carcasses chilled quickly lower mass losses were observed. The positive effect of ?26 °C in the shocking tunnel on the microbial quality of carcass and vacuum packed primal cuts was not as intensive as expected. As showed the above presented results of the study, the economic aspect of pork carcass chilling system first of all should be taken under consideration in meat production.

Practical applications

The study shown that very low temperatures in the shock tunnel in chilling process of the pig carcasses (e.g., ?26 °C) do not bring the expected results as a significant increase in the shelf life of meat cuts and quality of meat. Therefore, it is useful to modify the regime of temperature through the use in industrial practice of higher temperatures in the shock tunnel. The economic aspect of pork carcass chilling system first of all should be taken under consideration in choosing of the chilling method.     

Effect of Extreme Ultraviolet (EUV) Radiation and EUV Induced,N2 and O2 Based Plasmas on a PEEK Surface’s Physico-Chemical Properties and MG63 Cell Adhesion

Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility. In this work, extreme ultraviolet (EUV) radiation and two low-temperature, EUV induced, oxygen and nitrogen plasmas were used for surface modification of polyetheretherketone. Polymer samples were irradiated with 100, 150, and 200 pulses at a 10 Hz repetition rate. The physical and chemical properties of EUV and plasma modified PEEK surfaces, such as changes of the surface topography, chemical composition, and wettability, were examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and goniometry. The human osteoblast-like MG63 cells were used for the analysis of cell viability and cell adhesion on all modified PEEK surfaces. EUV radiation and two types of plasma treatment led to significant changes in surface topography of PEEK, increasing surface roughness and formation of conical structures. Additionally, significant changes in the chemical composition were found and were manifested with the appearance of new functional groups, incorporation of nitrogen atoms up to ~12.3 at.% (when modified in the presence of nitrogen), and doubling the oxygen content up to ~25.7 at.% (when modified in the presence of oxygen), compared to non-modified PEEK. All chemically and physically changed surfaces demonstrated cyto-compatible and non-cytotoxic properties, an enhancement of MG63 cell adhesion was also observed.     

Precipitated green pigments: products of chromate postgalvanic waste utilization

The paper reports on obtaining highly dispersed chromium(III) silicates and chromium(III) oxides from postchromating waste by reduction of Cr(VI) to Cr(III) with hydrazine as a reducing agent. Chromium(III) salt solution and sodium silicate or hydroxide solutions have been used to precipitate green pigments (silicates and oxides). The effect of the precipitation parameters on the quality of green pigments obtained has been studied, and the optimum parameters ensuring getting the product of well-developed surface area and possibly lowest diameter of primary particles have been established. The precipitated silicates and oxides have been subjected to physicochemical analysis to determine bulk density; capacities to absorb water, dibutyl phthalate, and paraffin oil; particles size; particle size distribution; and surface morphology of chromium pigment surfaces. The adsorptive properties of the oxide and silicate pigments have also been examined. The XRD analysis documented that the chromium(III) silicate pigments obtained are amorphous. In addition, the pigments have been subjected to a colorimetric appraisal using the CIE L*a*b* color space system. The high-quality green pigments obtained have shown high dispersion, small tendency to agglomerate formation, and repeatable green hue. The parameters of the products are promising for their future technological use.     

Platinum, palladium and rhodium content in road dust, tunnel dust and common grass in Białystok area (Poland): a pilot study

The potential of near infrared spectroscopy (NIRS) for determining the total arsenic (As) content in the prostrate amaranth (Amaranthus blitoides S. Watson) was assessed. Seventy-four samples belonging to this species, were harvested at different maturity stages along the polluted area, and then were scanned by NIRS. Their As reference values were obtained by atomic absorption spectrometry and they were regressed against different spectral transformations using modified partial least square (MPLS) regression. First derivative transformation equation of the raw optical data, previously standardized by standard normal variate (SNV) and De-trending (DT) transformations, resulted in a coefficient of determination (r(2)) in the external validation of 0.63, indicative of equations that can be used for a correct separation of the samples into low, medium and high groups. The standard deviation to standard error of prediction ratio (RPD) and range to standard error of prediction ratio (RER) for the first derivative equation were similar to those obtained for other trace metal calibrations reported in NIRS reflectance. Major cell components such as chlorophyll, lipids, starch and proteins were used by MPLS for modeling the equations. The use of NIRS for the determination of the As content in A. blitoides plants offers an important saving of time and cost of analysis.     

Highly dispersed green silicate and oxide pigments precipitated from model systems of postgalvanic waste

A procedure was worked out to obtain highly dispersed green silicate and oxide pigments precipitated from postgalvanic waste. The highly dispersed chromium(III) silicates and oxides were produced from the waste, originating from chromium plating, by reduction of Cr(VI) to Cr(III) employing various reducing agents. All the reductions were conducted in an acidic medium. Solutions of Cr(III), obtained in reducing processes, were employed to precipitate silicate pigments (using sodium metasilicate solution and containing mainly chromium(III) silicates) and oxide pigments (using sodium hydroxide and containing chromium(III) oxides). The precipitated silicates and oxides were subjected to a comprehensive physicochemical analysis (estimating bulk density, capacities to absorb water, dibutyl phthalate, paraffin oil, particle size distribution, and morphology of particle surface). Precipitation process (its parameters) and heating of the reactive mixture exerts a significant effect on the principal physicochemical properties of the pigments. The heating significantly affects first of all color shade of the obtained silicate and oxide pigments as well as their dispersion. Coprecipitated chromium(III) and iron(III) silicates exhibit a brownish color and a reasonably uniform character. Apart from primary agglomerates (in the range of 414-717 nm), they contain small amounts of secondary agglomerates (in the range of 4154-6445 nm). Best physicochemical parameters have been demonstrated by chromium pigments which have been precipitated from chromium solutions reduced using hydrogen peroxide. Chromium(III) oxides deserve particular distinction since their structure includes primary particles, primary agglomerates but is completely free of secondary agglomerates. The pigments manifest a brightly green color and a low capacity to absorb water (100 cm3 x 100 g(-1)). Application of hydrophobicity-inducing agents in the course of precipitation has corrected physicochemical parameters of both the oxides and silicates of chromium(II). Their bulk densities have been clearly decreased (to as low as below 250 g x L(-1) in the case of chromium(III) silicate), while capacities to absorb paraffin oil have increased to as much as 750 cm3 x 100 g(-1) for chromium(II) oxide. The respective particle size distribution has shown a tendency for disappearance of large accumulations of secondary agglomerates.     

Application of carbon-coated TiO2 for decomposition of methylene blue in a photocatalytic membrane reactor

An application of carbon-coated TiO(2) for decomposition of methylene blue (MB) in a photocatalytic membrane reactor (PMR), coupling photocatalysis and direct contact membrane distillation (DCMD) was investigated. Moreover, photodegradation of a model pollutant in a batch reactor without membrane distillation (MD) was also examined. Carbon-modified TiO(2) catalysts containing different amount of carbon and commercially available TiO(2) (ST-01) were used in this study. The carbon-coated catalyst prepared from a mixture of ST-01 and polyvinyl alcohol in the mass ratio of 70/30 was the most effective in degradation of MB from all of the photocatalysts applied. Photodecomposition of MB on the recovered photocatalysts was lower than on the fresh ones. The photodegradation of MB in the PMR was slower than in the batch reactor, what probably resulted from shorter time of exposure of the catalyst particles to UV irradiation. The MD process could be successfully applied for separation of photocatalyst and by-products from the feed solution.     

Ion release by endodontic grade glass-ionomer cement

Cylindrical specimens (6 mm high × 4 mm diameter) of the endodontic grade glass-ionomer (Ketac Endo) were exposed to various media for 1 week, after which changes in their mass, pH of storage medium, and ion release were determined. In water, this cement was shown to release reasonable amounts of sodium, aluminium and silicon, together with smaller amounts of calcium and phosphorus, as well as taking up 2.41% by mass of water. A comparison with the restorative grade materials (Ketac Molar, ex 3M ESPE and Fuji IX, ex GC) showed both ion release and water uptake to be greater. All three cements shifted pH from 7 to around 6 with no significant differences between them. Other storage media were found to alter the pattern of ion release. Lactic acid caused an increase, whereas both saturated calcium hydroxide and 0.6% sodium hypochlorite, caused decreases. This suppression of ion-release may be significant clinically. Aluminium is the most potentially hazardous of the ions involved but amounts released were low compared with levels previously reported to show biological damage.     

Development of new heterobicationic monomethine dyes as effective photoinitiator of free radical polymerization in visible‐light region

The dye initiators consisting of N‐[3‐(p‐alkylpyridine)propyl]‐2‐[N‐(3‐bromopropyl)quinoline]‐2‐methylenebenzotiazolium diiodides as chromophores and n‐butyltriphenylborate anion as electron donor were prepared to achieve an efficient photoinitiator of free radical polymerization in a visible‐light region. The relative photoinitiating efficiencies of novel photoinitiators of vinyl monomers polymerization were evaluated. The results obtained clearly documented that the bicationic photoinitiators exhibit a marked increase in the photoinitiation ability compared to the initiators consisting of a single charged hemicyanine dye. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008