Authenticity and quality of animal origin food investigated by stable‐isotope ratio analysis

Authentication of a food product is the procedure by which it is verified that the product matches the statements on the label, and that it conforms to what is established by regulations. This testing process includes analysis of the ingredients, determination of the geographical origin, and examination of the production methods. In particular, the use of rapid, effective and reliable analytical methods, when correctly applied to verify the authenticity and the traceability of the product, represents a valuable and irreplaceable tool for the authorities to carry out control functions. Tools and methodologies from scientific innovation and technological evolution can help to quickly locate particularly sophisticated frauds and adulterations. The feeding regime of livestock is a fundamental issue for the properties and safety of animal origin food, but this regime is often hidden from the consumer, making the zootechnical sector more prone to fraudulent practices. This review reports the results recently obtained in authentication of animal origin food by the application of stable‐isotope ratio analysis, the most promising analytical technique in this field.© 2012 Society of Chemical Industry     

Correlating mechanical and electrical properties of filler‐loaded polyurethane fluoroelastomers: The influence of carbon black

The dynamic mechanical properties and electrical conductivity of a class of polyurethane fluoroelastomers filled with different carbon black types and loadings were investigated. In particular, finely structured and coarsely structured carbon blacks were considered. Dynamic mechanical analysis (DMA) on the unfilled fluoroelastomer confirmed the phase‐segregated nature of this copolymer. The dynamic mechanical behavior of elastomeric compounds reinforced with finely structured carbon black was found to be strongly influenced by the filler content above a threshold value. This behavior may be attributed to the formation of carbon black aggregates and three‐dimensional anisotropic structures at increasing filler loading. Such an effect was not observed in compounds filled with coarsely structured carbon black particles, which do not seem to form higher level structures. These observations were supported by calculations on the hydrodynamic effect of the filler on the storage modulus G′ of carbon black–loaded compounds. Electrochemical impedance spectroscopy measurements on filled fluoroelastomers revealed the presence of an electrical percolation threshold for finely structured carbon black–filled compounds that supports the hypothesis of the presence of a three‐dimensional anisotropic network forming at high filler loading. No percolation threshold was found in coarsely structured carbon black–filled compounds in accordance with DMA. These results can provide useful guidelines for the design of high‐performance carbon black–filled polyurethane fluoroelastomers. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Novel probiotic candidates for humans isolated from raw fruits and vegetables

This study was aimed at determining the probiotic potential of a large number of autochthonous lactic acid bacteria isolated from fruit and vegetables. Survival under simulated gastric and intestinal conditions showed that 35% of the strains, mainly belonging to the species Lactobacillus plantarum maintained high cell densities. Selected strains did not affect the immune-mediation by Caco-2 cells. All strains stimulated all 27 immune-mediators by peripheral blood mononuclear cells (PBMC). A significant (P < 0.05; P < 0.01) increase of the major part of cytokines and growth factors was found. A few chemokines were stimulated. Immune-mediators with pro-inflammatory activity (IL-17, EOTAXIN and IFNγ) were significantly (P < 0.01) stimulated by all strains, followed by IL-1b > IP-10 > IL-6 > MIP1α. Stimulation of IL-12, IL-2 and IL-7 was strain dependent. Only a few strains increased the synthesis of cytokines with anti-inflammatory activity. Six L. plantarum strains were further selected. Four were defined as the strongly adhesive strains (more than 40 bacteria adhering to one Caco-2 cell), and 2 as the adhesive strains (5–40 bacteria adhering to one Caco-2 cell). Five strains grew and acidified chemically defined medium with fructo-oligosaccharides (FOS) as the only carbon source. End-products of FOS fermentation were found. All strains inhibited enterohemorragic Escherichia coli K12 and Bacillus megaterium F6 isolated from human sources. The results of this study showed that some autochthonous lactic acid bacteria from raw fruit and vegetables have functional features to be considered as novel probiotic candidates.     

TRPM2 Oxidation Activates Two Distinct Potassium Channels in Melanoma Cells through Intracellular Calcium Increase

Tumor microenvironments are often characterized by an increase in oxidative stress levels. We studied the response to oxidative stimulation in human primary (IGR39) or metastatic (IGR37) cell lines obtained from the same patient, performing patch-clamp recordings, intracellular calcium ([Ca²⁺]_i) imaging, and RT-qPCR gene expression analysis. In IGR39 cells, chloramine-T (Chl-T) activated large K⁺ currents (KROS) that were partially sensitive to tetraethylammonium (TEA). A large fraction of KROS was inhibited by paxilline—a specific inhibitor of large-conductance Ca²⁺-activated BK channels. The TEA-insensitive component was inhibited by senicapoc—a specific inhibitor of the Ca²⁺-activated KCa3.1 channel. Both BK and KCa3.1 activation were mediated by an increase in [Ca²⁺]_i induced by Chl-T. Both KROS and [Ca²⁺]_i increase were inhibited by ACA and clotrimazole—two different inhibitors of the calcium-permeable TRPM2 channel. Surprisingly, IGR37 cells did not exhibit current increase upon the application of Chl-T. Expression analysis confirmed that the genes encoding BK, KCa3.1, and TRPM2 are much more expressed in IGR39 than in IGR37. The potassium currents and [Ca²⁺]_i increase observed in response to the oxidizing agent strongly suggest that these three molecular entities play a major role in the progression of melanoma. Pharmacological targeting of either of these ion channels could be a new strategy to reduce the metastatic potential of melanoma cells, and could complement classical radio- or chemotherapeutic treatments.     

Green procedure for the preparation of scented alcohols from carbonyl compounds

Several alcohols--interesting as cosmetic fragrances whose main preparative route on an industrial scale or in the research laboratory is the reduction of the corresponding carbonyl compound--were obtained by a solvent-free methodology in a green chemistry context. The process involves the simple mixing of the carbonyl compound with sodium borohydride dispersed in wet alumina in the solid state; the conversions of the carbonyl compounds were obtained in good yields within short reaction times, without energy consumption. The following carbinols were studied: octan-3-ol, 2-cineolylols (endo-exo mixture), alpha-ionol, 4-methylbenzyl alcohol, 1-phenylethanol, trans-cinnamyl alcohol, p-anisyl alcohol, 4-phenyl-3-buten-2-ol.     

Proton NMR relaxation study of swelling and gelatinisation process in rice starch–water samples

Proton transverse magnetization decay curves of rice flour starch–water samples were measured and analysed for the presence of four components in the relaxation curve. T₂ values were interpreted on the basis of the diffusive and chemical exchange model that provided evidence for extra granular bulk water and three more water populations whose relaxation rate is governed by diffusive and chemical exchange with starch components. The analysis of relaxation data provided information on dynamics of water molecules as well as on the size and dispersion of diffusive domains. Furthermore, by measuring solid to liquid ratio, transverse and longitudinal relaxation curves of starch–water mixtures at increasing temperatures – from 20 to 77 °C – swelling and gelatinisation processes were monitored.