474 research outputs found

    Development and Evaluation of qPCR Detection Method and Zn-MgO/Alginate Active Packaging for Controlling Listeria monocytogenes Contamination in Cold-Smoked Salmon

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    To answer to food industry requests to monitor the presence of L. monocytogenes in cold-smoked salmon samples and to extend their shelf-life, a qPCR protocol for the detection of L. monocytogenes, and an antibacterial active packaging reinforced with zinc magnesium oxide nanoparticles (Zn-MgO NPs) were developed. The qPCR allowed the sensitive and easy detection of L. monocytogenes in naturally contaminated samples, with specificity in full agreement with the standard methods. The halo diusion study indicated a high antibacterial eciency of 1 mg/mL Zn-MgO NPs against L. monocytogenes, while the flow cytometry showed only moderate cytotoxicity of the nanoparticles towards mammalian cells at a concentration above 1 mg/mL. Thus, the novel active packaging was developed by using 1 mg/mL of Zn-MgO NPs to reinforce the alginate film. Cold-smoked salmon samples inoculated with L. monocytogenes and air-packed with the Zn-MgO NPs-alginate nanobiocomposite film showed no bacterial proliferation at 4 C during 4 days. In the same condition, L. monocytogenes growth in control contaminated samples packed with alginate film alone. Our results suggest that Zn-MgO nanoparticles can extend the shelf-life of cold-smoked salmon samples

    Mainstreaming biodiversity for food and nutrition into policies and practice: methodologies and lessons learned from four countries

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    This paper outlines the methodology for mainstreaming biodiversity developed by the Biodiversity for Food and Nutrition Project (BFN), a multi-country initiative led by Brazil, Kenya, Sri Lanka and Turkey. BFN explored the nutritional properties of traditional and/or neglected native edible species, both wild and cultivated (including varieties and landraces), and used this knowledge to incorporate local agricultural biodiversity into national and global policy instruments that address food and nutrition security through the promotion of healthy, diversified and sustainable diets. Across the four countries, the project adopted a three-pillar approach for mainstreaming biodiversity for food and nutrition into policies and practices by: 1) Providing Evidence, 2) Influencing Policy, and 3) Raising Awareness. Case study examples from Brazil, Kenya, Turkey, and Sri Lanka demonstrate how the approach can be adapted to suit specific country contexts and how a multi-level, cross-sectoral partnership-based approach can create an enabling environment for mainstreaming biodiversity to improve nutrition

    Eficiência energética do processo top-down na produção de nanofibrilas de celulose.

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    O presente estudo tem por objetivo produzir nanofibrilas de celulose vegetal com polpa kraft marrom por meio de pré-tratamento enzimático e posteriormente mecânico, com o intuito de redução no consumo energético. Para isso, as amostras de polpas de celulose foram previamente desestruturadas através da saturação em água e desmembradas em um desfibrador mecânico. Após, armazenadas sob refrigeração a 5°C. Para o pré-tratamento enzimático utilizou-se a enzima comercial Cellic Ctec-2, em porcentagens que variaram de 0,01 a 0,1% por meio de hidrólise controlada com pH neutro e temperatura ambiente durante uma hora, sendo que as amostras com quantidade de 0,01% sofreram hidrólise por diferentes períodos (1 e 2 horas). Após o tempo de hidrólise, a polpa foi processada em um moinho de discos, o qual possui medidor de energia. As polpas sofreram passagens em ciclos pelo moinho, até o ponto de se transformarem em um gel viscoso. Para estacionar a ação enzimática o conteúdo foi aquecido à 85°C. Os géis foram armazenados em resfriamento de 5°C. O processo foi caracterizado pelo gasto energético medido a cada amostra com suas testemunhas, além de ser medido o rendimento de cada gel produzido. De acordo com os resultados, foi observado que o processo combinado apresentou-se viável para a produção de nanofibrilas, pois este, diminui o tempo e gasto energético do processo. A polpa marrom mesmo sem ter passado por processos de deslignificação, mostrou-se promissora na produção das nanofibrilas de celulose vegetal

    Multifrequency monitoring of the blazar 0716+714 during the GASP-WEBT-AGILE campaign of 2007

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    Since the CGRO operation in 1991-2000, one of the primary unresolved questions about the blazar gamma-ray emission has been its possible correlation with the low-energy (in particular optical) emission. To help answer this problem, the Whole Earth Blazar Telescope (WEBT) consortium has organized the GLAST-AGILE Support Program (GASP) to provide the optical-to-radio monitoring data to be compared with the gamma-ray detections by the AGILE and GLAST satellites. This new WEBT project started in early September 2007, just before a strong gamma-ray detection of 0716+714 by AGILE. We present the GASP-WEBT optical and radio light curves of this blazar obtained in July-November 2007, about various AGILE pointings at the source. We construct NIR-to-UV spectral energy distributions (SEDs), by assembling GASP-WEBT data together with UV data from the Swift ToO observations of late October. We observe a contemporaneous optical-radio outburst, which is a rare and interesting phenomenon in blazars. The shape of the SEDs during the outburst appears peculiarly wavy because of an optical excess and a UV drop-and-rise. The optical light curve is well sampled during the AGILE pointings, showing prominent and sharp flares. A future cross-correlation analysis of the optical and AGILE data will shed light on the expected relationship between these flares and the gamma-ray events.Comment: 5 pages, 5 figures, to be published in A&A (Letters); revised to match the final version (changes in Fig. 5 and related text

    Measurement of the K_L \to \pi\mu\nu form factor parameters with the KLOE detector

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    Using 328 pb^{-1}of data collected at DAFNE corresponding to \sim 1.8 million KLπμνK_L\to \pi\mu\nu decays, we have measured the Kμ3K_{\mu 3} form factor parameters. The structure of the KπK-\pi vector-current provides information about the dynamics of the strong interaction; its knowledge is necessary for evaluation of the phase-space integral required for measuring the CKM matrix element VusV_{us} and for testing lepton universality in kaon decays. Using a new parametrization for the vector and scalar form factors, we find λ+\lambda_+=\pt(25.7\pm 0.6),-3, and λ0\lambda_0=\pt(14.0\pm 2.1),-3,. Our result for λ0\lambda_0, together with recent lattice calculations of fπf_\pi, fKf_K and f(0)f(0), satisfies the Callan-Trieman relatio

    Measurements of the Absolute Branching Ratios for the Dominant KL Decays, the KL Lifetime, and Vus with the KLOE Detector

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    From a sample of about 10^9 Phi mesons produced at DAFNE, we have selected KL mesons tagged by observing KS->pi+pi- decays. We present results on the major KL branching ratios, including those of the semileptonic decays needed for the determination of Vus. These branching ratio measurements are fully inclusive with respect to final-state radiation. The KL lifetime has also been measured.Comment: Submitted to Phys. Lett.
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