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.     

The effect of vegetable and spice addition on the acrylamide content and antioxidant activity of innovative cereal products

The aim of the work was to assess the impact of vegetable and spice addition on the acrylamide content and antioxidant activity of extruded cereal crisps. The foods were based on grain ingredients, such as brown rice, whole grain flour, wheat bran, with different vegetables. Products from one group contained green vegetables, such as broccoli and zucchini; garlic was included as a flavour additive (0.75–1.50%). The second group of crisps consisted of similar cereal ingredients with pumpkin and cinnamon; additionally ginger was included as a flavour additive (0.75–1.50%). The results indicate that the production of a new, innovative product with appropriate nutritional value and acceptable quality is a complex process. The production process significantly changed the nutritional value of the product. The content of acrylamide in zucchini and broccoli crisps was relatively low; ranging from 78 to 86 μg/kg of product. The addition of garlic did not significantly affect the acrylamide content in the final product. For cereal–pumpkin crisps, the acrylamide content was 7 times higher in comparison with zucchini and broccoli products. The acrylamide content in pumpkin and ginger crisps exceeded the benchmark level. The antioxidant activity of the pumpkin product was significantly higher (p < 0.05) than for crisps with green vegetables.     

Properties of sucrose-free chocolates enriched with viable lactic acid bacteria

Chocolate formulated with isomalt and enriched with lactic acid bacteria Streptococcus thermophilus MK-10 and Lactobacillus delbrueckii subsp. bulgaricus 151, added in the form of powdered yoghurt, prepared by spray-drying is a sucrose-free, low-calorie product with functional properties. The technique of the production of chocolate sweetened with isomalt and containing live cells of the aforementioned bacterial strains has been established. Physicochemical and sensory properties of this product as well as survival of cells during 6-months storage at 4 and 18 °C have been determined. The isomalt-containing yoghurt chocolates displayed satisfactory sensory attributes. Their calorific value and consistency (hardness) were similar to those of control sucrose-free chocolates. The total acidity of yoghurt and standard milk chocolates was also similar, whereas yoghurt-containing dark chocolates displayed higher acidity. The characteristics of yoghurt-containing chocolates were a relatively low solid substance content (96.82–96.91% w/w), low Casson viscosity and yield value for milk chocolate masses, and enhanced rheological parameters for dark chocolate masses compared with control sucrose-free chocolates. Because the total number of lactic acid bacteria after 6-months storage at 4 and 18 °C was high (approximately 10⁷ cfu/g), the sucrose-free yoghurt-containing chocolates can be regarded as functional foods.     

An association of CYP2A6 genotype and smoking topography.

Nicotine is metabolized into biologically inactive cotinine primarily by the cytochrome P450 enzyme CYP2A6. CYP2A6 genetic variations have been phenotypically grouped as slow, intermediate, and normal metabolizers. Slow metabolizers smoke fewer cigarettes daily and weekly, and have lower carbon monoxide (CO) and plasma nicotine levels, suggesting a reduced smoking rate compared with normal metabolizers. CYP2A6 also is involved in the metabolic activation of tobacco-specific procarcinogenic nitrosamines, such as 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). NNK is one of the most abundant and potent procarcinogens in cigarette smoke. The present study investigated the association of CYP2A6 genotype with smoking topography, a quantifiable measure of smoking behavior, in a sample of treatment-seeking smokers prior to treatment. Smoking topography measures indicative of quantity of smoke exposure--number of puffs, mean puff volume, and total puff volume--were the outcome variables. Covariates associated with smoking topography were included in the analyses. Results indicated that CYP2A6 genotype group had a significant effect on mean puff volume and total puff volume, but not number of puffs, such that slow metabolizers exhibited reduced puffing compared with others. Smokers having CYP2A6 variants resulting in low activity metabolize nicotine more slowly, and convert procarcinogen nitrosamines to carcinogens more slowly, than do normal metabolizers. The results from this study also suggest a behavioral mechanism that may account for reduced cancer risk in slow metabolizers.     

Aversive Learning Deficits and Depressive-Like Behaviors Are Accompanied by an Increase in Oxidative Stress in a Rat Model of Fetal Alcohol Spectrum Disorders: The Protective Effect of Rapamycin

Fetal alcohol spectrum disorders (FASDs) are one of the most common consequences of ethanol exposure during pregnancy. In adulthood, these disorders can be manifested by learning and memory deficits and depressive-like behavior. Ethanol-induced oxidative stress may be one of the factors that induces FASD development. The mammalian target of the Rapamycin (mTOR) signaling pathway that acts via two distinct multiprotein complexes, mTORC1 and mTORC2, can affect oxidative stress. We investigated whether mTOR-dependent or mTOR-independent mechanisms are engaged in this phenomenon. Thus, Rapamycin—a selective inhibitor of mTORC1, Torin-2—a non-selective mTORC1/mTORC2 inhibitor, and FK-506—a drug that impacts oxidative stress in an mTOR-independent manner were used. Behavioral tests were performed in adult (PND60-65) rats using a passive avoidance (PA) task (aversive learning and memory) and forced swimming test (FST) (depressive-like behaviors). In addition, the biochemical parameters of oxidative stress, such as lipid peroxidation (LPO), as well as apurinic/apyrimidinic (AP)-sites were determined in the hippocampus and prefrontal cortex in adult (PND65) rats. The rat FASD model was induced by intragastric ethanol (5 g/kg/day) administration at postnatal day (PND)4–9 (an equivalent to the third trimester of human pregnancy). All substances (3 mg/kg) were given 30 min before ethanol. Our results show that neonatal ethanol exposure leads to deficits in context-dependent fear learning and depressive-like behavior in adult rats that were associated with increased oxidative stress parameters in the hippocampus and prefrontal cortex. Because these effects were completely reversed by Rapamycin, an mTORC1 inhibitor, this outcome suggests its usefulness as a preventive therapy in disorders connected with prenatal ethanol exposure.     

Advancing membrane electrodes and optical ion sensors

While potentiometric sensors experienced a golden age in the 1970s that drove innovation and implementation in the clinical laboratory as sensors of choice, it has been only fairly recently that a theoretical understanding coupled with modern materials approaches transformed the area of membrane electrodes from a playful, yet empirical field to one firmly rooted in scientific understanding. This paper summarizes key progress in the field during the past two decades, emphasizing that the key impulses at the time originated from the emerging field of optical ion sensors. This simplified and transformed the underlying theory of their potentiometric membrane electrode counterparts, where subsequently substantial progress was made, including the realization of ultra-trace detection limits. The better understanding of zero-current ion fluxes and transport processes in turn allowed the development of approaches utilizing dynamic electrochemistry principles, thereby drastically expanding the field of membrane electrodes and making available a range of new methodologies that would have been difficult to predict only a few years ago. These significant developments are now starting to come back and influence the field of optical sensors, where the control and triggering of dynamic processes, away from simpler equilibrium principles, are becoming a highly promising field of research.     

Passivation of Al–Cr–Fe and Al–Cu–Fe–Cr complex metallic alloys in 1 M H2SO4 and 1 M NaOH solutions

The corrosion mechanisms of Al–Cr–Fe and Al–Cu–Fe–Cr complex metallic alloys have been investigated by potentiodynamic and potentiostatic polarization. Very good passivation of the Al–Cr–Fe surface is exhibited from 1 M H₂SO₄ to 1 M NaOH solutions, which was confirmed by ICP-OES analysis over a period of 273 days. Potentiostatically formed passive films analysed by XPS revealed chromium enrichment in the outermost layer of the aluminium oxy-hydroxide film. Although Al–Cu–Fe–Cr showed passivation during potentiodynamic polarization, heavy active corrosion at OCP was revealed by ICP-OES. For the Al–Cu–Fe–Cr alloy, the 10% content of Cr is insufficient to maintain a protective “chemically stable” Cr oxide/hydroxide.     

Organic acids catalyzed polymerization of ε‐caprolactone: Synthesis and characterization

Environmentally friendly organocatalytic synthesis of aliphatic polyesters was studied. The catalysis investigated is novel, and lends itself well to the potential production of valuable biodegradable products. The reactions were based on an organic acids‐catalyzed ring‐opening polymerization of ε‐caprolactone with fatty acid derivatives as the initiator and were performed in the absence of solvents. The chemical structures of the functionalized polymers were confirmed by ¹H and ¹³C‐NMR spectra. Polymers with different molecular weights, in the range 10,900–15,200 were obtained in the presence of fumaric acid as catalyst. The thermal properties of the functionalized PCLs were determined by modulated differential scanning calorimetry and thermogravimetric analysis. The MDSC results verified that the crystallinity and the melting point of the lipid‐functionalized polymers were lower than that of the unfunctionalized poly(ε‐caprolactone). The hydrolytic degradation of the functionalized polymer was also investigated. The result shows the degradation rate was affected by the presence of oleic acid derivatives in the polymer molecule. The lipid‐functionalized polymers synthesized by the metal‐free polymerization systems seem to be suitable biodegradable polyesters for use in biomedical and pharmacological applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011