154 research outputs found

    Analyse du profil de texture (tpa) et caractérisation physicochimiques des pâtes de tamarin enrichies en feuilles de moringa oleifera

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    Le but de cette étude était de caractériser les propriétés physicochimiques (Aw, couleur, teneur en eau) et rhéologiques (analyse du profil de texture) des pâtes de tamarin enrichies avec différentes teneurs en Moringa oleifera. Cette supplémentation permet d’accroître la teneur protéique des produits et ainsi de participer activement au programme national de Madagascar pour la nutrition. Cette étude a permis de définir la limite haute d’acceptabilité d’ajout en Moringa oleifera. Au-delà d’un ajout de 30% en Moringa oleifera dans les pâtes de tamarin, les propriétés texturales et physicochimiques sont significativement différentes. En parallèle, une étude de vieillissement des différents produits sur 30 jours a été réalisée. Cette étude démontre le potentiel d’exploitation industriel des pâtes de tamarin enrichies avec 30% de Moringa oleifera. Ainsi ce produit alimentaire contribuerai activement au plan d’action national pour la nutrition tout en valoriser les ressources naturelles de Madagascar.Mots-clés: pâtes de fruits, Moringa oleifera, tamarin, profil de texture, propriétés physicochimiques. Texture profile analysis (tpa) and physicochemical properties study of tamarins jelly enriched with moringa oléiféra leaves The purpose of this study was to characterize the physicochemical properties (Aw, color, relative humidity) and rheological properties (texture profile analysis) of tamarind pastes enriched with different quantities of Moringa oleifera. This supplement helps to increase the protein content of the products and thus actively participate in the national program for nutrition in Madagascar. This study has identified the upper acceptability limit of adding in Moringa oleifera. Beyond the addition of 30% of Moringa oleifera in fruit pastes, textural and physicochemical properties are significantly different. In parallel, a study of aging for all the above products over 30 days was carried out. This study highlights the potential for industrial exploitation of Tamarind pastes enriched with 30% Moringa oleifera. In this way this food would contribute actively in the nation action plan of nutrition of Madagascar while encouraging the natural resources of Madagascar.Keywords: fruits pastes, Moringa oleifera, tamarin, texture profile analysis, chemicophysical properties

    Inhomogeneous ferrimagnetic-like behavior in Gd2/3Ca1/3MnO3 single crystals

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    We present a study of the magnetic properties of Gd2/3Ca1/3MnO3 single crystals at low temperatures. We show that this material behave as an inhomogeneous ferrimagnet. In addition to small saturation magnetization at 5 K, we have found history dependent effects in the magnetization and the presence of exchange bias. These features are compatible with microscopic phase separation in the clean Gd2/3Ca1/3MnO3 system studied.Comment: 7 pages, 6 figures, submitted Journal of Magnetism and Magnetic Material

    Dielectric catastrophe at the magnetic field induced insulator to metal transition in Pr1-xCaxMnO3 (x=0.30, 0.37) crystals

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    The dielectric permittivity and resistivity have been measured simultaneously as a function of magnetic field in Pr1-xCaxMnO3 crystals with different doping. A huge increase of dielectric permittivity was detected near percolation threshold. The dielectric and conductive properties are found to be mutually correlated throughout insulator to metal transition evidencing the dielectric catastrophe phenomenon. Data are analyzed in a framework of Maxwell-Garnett theory and the Mott-Hubbard theory attributed to the role of strong Coulomb interactions.Comment: 5 pages, 5 figure

    Investigating the effect of synthesis selection on O3-sodium layered oxide structural changes and electrochemical properties

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    Transition metal (TM) layered oxides constitute a promising family of materials for use in Na-ion battery cathodes. Here O3-Na (Ni1/3Mn1/3Fe1/3) O2 was synthesised using optimised sol-gel and solid-state routes, and the physico- and electrochemical natures of the resulting materials were thoroughly studied. Significant differences in electrochemical behaviour were observed, and the use of in operando XRD determined this stemmed from the suppression of the P3 phase in the sol-gel material during cycling. This was attributable to differences in the degree of transition metal migration in the materials ensuing from the selection of synthetic route. This demonstrates that not only the choice of material, but also that of synthesis route, can have dramatic impact on the resulting structural and electrochemical nature, making such considerations critical in the future development of advanced Na-ion cathode materials

    A Moving Boundary Flux Stabilization Method for Cartesian Cut-Cell Grids using Directional Operator Splitting

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    An explicit moving boundary method for the numerical solution of time-dependent hyperbolic conservation laws on grids produced by the intersection of complex geometries with a regular Cartesian grid is presented. As it employs directional operator splitting, implementation of the scheme is rather straightforward. Extending the method for static walls from Klein et al., Phil. Trans. Roy. Soc., A367, no. 1907, 4559-4575 (2009), the scheme calculates fluxes needed for a conservative update of the near-wall cut-cells as linear combinations of standard fluxes from a one-dimensional extended stencil. Here the standard fluxes are those obtained without regard to the small sub-cell problem, and the linear combination weights involve detailed information regarding the cut-cell geometry. This linear combination of standard fluxes stabilizes the updates such that the time-step yielding marginal stability for arbitrarily small cut-cells is of the same order as that for regular cells. Moreover, it renders the approach compatible with a wide range of existing numerical flux-approximation methods. The scheme is extended here to time dependent rigid boundaries by reformulating the linear combination weights of the stabilizing flux stencil to account for the time dependence of cut-cell volume and interface area fractions. The two-dimensional tests discussed include advection in a channel oriented at an oblique angle to the Cartesian computational mesh, cylinders with circular and triangular cross-section passing through a stationary shock wave, a piston moving through an open-ended shock tube, and the flow around an oscillating NACA 0012 aerofoil profile.Comment: 30 pages, 27 figures, 3 table

    Identification of stable QTLs for vegetative and reproductive traits in the microvine (Vitis vinifera L.) using the 18 K Infinium chip

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    UMR AGAP - équipe DAAV - Diversité, adaptation et amélioration de la vigne[b]Background[/b] [br/]The increasing temperature associated with climate change impacts grapevine phenology and development with critical effects on grape yield and composition. Plant breeding has the potential to deliver new cultivars with stable yield and quality under warmer climate conditions, but this requires the identification of stable genetic determinants. This study tested the potentialities of the microvine to boost genetics in grapevine. A mapping population of 129 microvines derived from Picovine x Ugni Blanc flb, was genotyped with the Illumina® 18 K SNP (Single Nucleotide Polymorphism) chip. Forty-three vegetative and reproductive traits were phenotyped outdoors over four cropping cycles, and a subset of 22 traits over two cropping cycles in growth rooms with two contrasted temperatures, in order to map stable QTLs (Quantitative Trait Loci). [br/][b]Results[/b] [br/]Ten stable QTLs for berry development and quality or leaf area were identified on the parental maps. A new major QTL explaining up to 44 % of total variance of berry weight was identified on chromosome 7 in Ugni Blanc flb, and co-localized with QTLs for seed number (up to 76 % total variance), major berry acids at green lag phase (up to 35 %), and other yield components (up to 25 %). In addition, a minor QTL for leaf area was found on chromosome 4 of the same parent. In contrast, only minor QTLs for berry acidity and leaf area could be found as moderately stable in Picovine. None of the transporters recently identified as mutated in low acidity apples or Cucurbits were included in the several hundreds of candidate genes underlying the above berry QTLs, which could be reduced to a few dozen candidate genes when a priori pertinent biological functions and organ specific expression were considered. [br/][b]Conclusions[/b] [br/]This study combining the use of microvine and a high throughput genotyping technology was innovative for grapevine genetics. It allowed the identification of 10 stable QTLs, including the first berry acidity QTLs reported so far in a Vitis vinifera intra-specific cross. Robustness of a set of QTLs was assessed with respect to temperature variatio

    Proteomic Analysis of Grape Berry Cell Cultures Reveals that Developmentally Regulated Ripening Related Processes Can Be Studied Using Cultured Cells

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    The original publication is available at http:/www.plosone.orgBackground: This work describes a proteomics profiling method, optimized and applied to berry cell suspensions to evaluate organ-specific cultures as a platform to study grape berry ripening. Variations in berry ripening within a cluster(s) on a vine and in a vineyard are a major impediment towards complete understanding of the functional processes that control ripening, specifically when a characterized and homogenous sample is required. Berry cell suspensions could overcome some of these problems, but their suitability as a model system for berry development and ripening needs to be established first. Methodology/Principal Findings: In this study we report on the proteomic evaluation of the cytosolic proteins obtained from synchronized cell suspension cultures that were established from callus lines originating from green, véraison and ripe Vitis vinifera berry explants. The proteins were separated using liquid phase IEF in a Microrotofor cell and SDS PAGE. This method proved superior to gel-based 2DE. Principal component analysis confirmed that biological and technical repeats grouped tightly and importantly, showed that the proteomes of berry cultures originating from the different growth/ripening stages were distinct. A total of twenty six common bands were selected after band matching between different growth stages and twenty two of these bands were positively identified. Thirty two % of the identified proteins are currently annotated as hypothetical. The differential expression profile of the identified proteins, when compared with published literature on grape berry ripening, suggested common trends in terms of relative abundance in the different developmental stages between real berries and cell suspensions. Conclusions: The advantages of having suspension cultures that accurately mimic specific developmental stages are profound and could significantly contribute to the study of the intricate regulatory and signaling networks responsible for berry development and ripening. © 2011 Sharathchandra et al.Publishers' Versio
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