266 research outputs found

    Actividad antioxidante de extractos de torta de aceite de semilla de Sclerocarya birrea

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    The antioxidant activity of methanolic extracts from Sclerocarya birrea kernel oil meal, extracted using two different methods was evaluated. The extraction was carried out using magnetic stirring of the material in methanol/water (80:20 v/v) overnight followed by two ultra-sonic treatments for 45 min. (Overnight extract, ONEXT) and three ultra-sonic treatments for 45 min. only (Ultra-sonic extract, USEXT), respectively. Three fractions were obtained from each extract and the contents of total phenolic compounds were determined in each fraction according to the Folin-Ciocalteau method as 34.6, 54.8, and 58.6 mg/g of dry product in ONEXT and 29.6, 84.8, 143.9 mg/g in USEXT, respectively. The antioxidant activity of the extracts was evaluated according to the β-carotene-linoleic acid assay, where the extracts and their fractions showed significant effect (pSe ha evaluado la actividad antioxidante de extractos metanólicos de torta de aceite de semilla de Sclerocarya birrea extraídos usando dos métodos diferentes. La extracción se llevó a cabo mediante agitación magnética del material en metanol/agua (80:20 v/v) durante toda la noche seguida de dos tratamientos con ultrasonidos durante 45 min. (extracto ONEXT) y solo tres tratamientos con ultrasonidos durante 45 min. (extracto USEXT), respectivamente. Se obtuvieron tres fracciones de cada extracto y el contenido total de compuestos fenólicos se determinó en cada fracción según el método de Folin-Ciocalteau como 34.6, 54.8 y 58.6 mg/g de producto seco en ONEXT y 29.6, 84.8 y 143.9 mg/g en USEXT, respectivamente. La actividad antioxidante de los extractos fue evaluada mediante el ensayo del β-carotenoácido linoleico donde los extractos y sus fracciones mostraron efectos significativos (

    La nueva base de datos “Ácidos Grasos de Semillas Oleaginosas” (SOFA)

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    More than 30 years i n formation about the fatty acid composit ion of wi ld plant seeds was collected f rom the appropriate pharmaceutical, botanical and chemical literature by the former Institute for Chemistry and Physics of Lipids of the Federal Center for Cereal, Potato and Lipid Research in Münster. Since it was very difficult to search this unique source of information, the collection was transferred into an electronically searchable database. This plan was supported by financial assistance of the German Ministry of Consumer Protection, Food and Agriculture. Since some month the database is available in the internet (http:\\www.bagkf.de/sofa) free of charge. Up to now more than 18.000 different tables with about 110.000 individual data are recallable from the database, by different types of search forms. An overview about the application of the different search forms as well as some examples for searches is given in this publication.Mas de 30 años de información sobre la composición en ácidos grasos de semillas de plantas silvestres ha sido recogida de la literatura farmacéutica, botánica y química por el antiguo Institute for Chemistry and Physics del Federal Center for Cereal, Potato and Lipid Research en Münster. Desde hace varios meses la base de datos está ya disponible sin cargo alguno en Internet (http:\\www.bagkf.de/sofa). Hasta ahora más de 18.000 tablas diferentes con alrededor de 110.000 datos individuales pueden obtenerse a partir de esa base de datos mediante diferentes tipos de búsquedas. Una panorámica de la aplicación de las diferentes posibles formas de búsquedas así como algunos ejemplos de búsquedas se dan en este artículo

    Zum Einfluss der Fütterung von Leindotterpresskuchen auf die Mast- und Schlachtleistung von Broilern aus ökologischer Mast

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    False flax (Camelina sativa) is a very beneficial oil seed in organic plant production. Its added value could be enhanced by using the oil cake in animal nutrition, which is very interesting for organic feeding due to the demand of farm grown crude protein and energy delivering plants. But European feed law does not allow such an use. An application for an amendment of the ordinance only seems promising, if it is possible to make a scientifically based proposal concerning the unproblematic amount of Camelina oil cake in the diet. Therefore in an organic feeding trial with a total of 192 broilers the effects of different amounts of Camelina oil cake (0%, 2.5%, 5% and 5% heat and pressure treated) in the diet concerning performance, carcass and meat quality were tested. The substitution of Camelina oil cake against soy cake till 5% caused inconsistent results concerning performance. Treated oil cake significantly caused poor performance and enlarged thyroid glands and livers. Carcass, meat, and fat quality remained unaffected. But anyway, a recommendation concerning the rea-sonable amount of Camelina oil cake in a broiler diet based on this single trial seems not feasible. Therefore further research has to be done

    Leindotterpresskuchen in ökologischen Futterrationen: Stand der Forschung

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    Organic farming needs home-grown energy and protein sources in livestock feeding. Due to the concept of mixed cropping systems with oilseeds like false flax (Camelina sativa (L.) Crantz) the possible use of its oilcake as a component of feeding rations is attracting attention of farmers. False flax is an undesired substance in the European rules on feeding stuffs and the use of its oilcake in animal feeding is subject of diverse research projects. A review of the recentThe experiences shows that the use of oilcake of false flax in monogastric animals can negatively affect sensory meat quality and metabolism obvious in enlarged organs. In ruminant feeding those effects are not observed. Further research is needed to find out adopted feeding rations for different livestock. In dairy feeding additional experiments on the effect on milk fat contents should confirm existing results

    Conservación a largo plazo de tres aceites no convencionales

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    Three samples, Sclerocarya birrea oil (SCO), Melon bug oil (Aspongubus viduatus) (MBO), and Sorghum bug oil (Agonoscelis pubescens) (SBO), were stored (autoxidized) in the dark at 30±2 °C for 24 months. Oil aliquots were withdrawn every 2-4 month for analyses of changes in four quality indexes, namely fatty acid composition, tocopherol content, peroxide value and oxidative stability index by Rancimat. After 24 months of storage the fatty acid composition of the three oils showed no change while tocopherol contents were decreased. SCO and MBO showed only slight changes in their oxidative stability as indicated by the peroxide value and induction period during the 24 months of storage. Sorghum bug oil showed a periodical increase in the peroxide value and had less stability as measured by the Rancimat in comparison to other oils.Tres muestras de aceite, Sclerocarya birrea oil (SCO), Melon bug oil (Aspongubus viduatus) (MBO), and Sorghum bug oil (Agonoscelis pubescens) (SBO), fueron almacenadas en la oscuridad a 30±2 °C durante 24 meses. Cada 2- 4 meses se toman alícuotas para analizar los cambios de calidad. Se determinaron la composición en ácidos grasos, el contenido en tocoferol, el índice de peróxidos y la estabilidad oxidativa mediante el aparato Rancimat. Después de 24 meses de almacenamiento, la composición en ácidos grasos no experimentó variación mientras que el contenido en tocoferol disminuyó en los tres aceites. SCO y MBO mostraron cambios minoritarios como se comprobó por los indices de peroxides y estabilidad a los 24 meses. SBO fue el menos estable de los tres aceites

    Amplitude equations near pattern forming instabilities for strongly driven ferromagnets

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    A transversally driven isotropic ferromagnet being under the influence of a static external and an uniaxial internal anisotropy field is studied. We consider the dissipative Landau-Lifshitz equation as the fundamental equation of motion and treat it in 1+11+1~dimensions. The stability of the spatially homogeneous magnetizations against inhomogeneous perturbations is analyzed. Subsequently the dynamics above threshold is described via amplitude equations and the dependence of their coefficients on the physical parameters of the system is determined explicitly. We find soft- and hard-mode instabilities, transitions between sub- and supercritical behaviour, various bifurcations of higher codimension, and present a series of explicit bifurcation diagrams. The analysis of the codimension-2 point where the soft- and hard-mode instabilities coincide leads to a system of two coupled Ginzburg-Landau equations.Comment: LATeX, 25 pages, submitted to Z.Phys.B figures available via [email protected] in /pub/publications/frank/zpb_95 (postscript, plain or gziped

    Improved Constraints on Northern Extratropical CO2 Fluxes Obtained by Combining Surface-Based and Space-Based Atmospheric CO2 Measurements

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    Abstract Top-down estimates of CO2 fluxes are typically constrained by either surface-based or space-based CO2 observations. Both of these measurement types have spatial and temporal gaps in observational coverage that can lead to differences in inferred fluxes. Assimilating both surface-based and space-based measurements concurrently in a flux inversion framework improves observational coverage and reduces sampling related artifacts. This study examines the consistency of flux constraints provided by these different observations and the potential to combine them by performing a series of 6-year (2010?2015) CO2 flux inversions. Flux inversions are performed assimilating surface-based measurements from the in situ and flask network, measurements from the Total Carbon Column Observing Network (TCCON), and space-based measurements from the Greenhouse Gases Observing Satellite (GOSAT), or all three data sets combined. Combining the data sets results in more precise flux estimates for subcontinental regions relative to any of the data sets alone. Combining the data sets also improves the accuracy of the posterior fluxes, based on reduced root-mean-square differences between posterior flux-simulated CO2 and aircraft-based CO2 over midlatitude regions (0.33?0.56?ppm) in comparison to GOSAT (0.37?0.61?ppm), TCCON (0.50?0.68?ppm), or in situ and flask measurements (0.46?0.56?ppm) alone. These results suggest that surface-based and GOSAT measurements give complementary constraints on CO2 fluxes in the northern extratropics and can be combined in flux inversions to improve constraints on regional fluxes. This stands in contrast with many earlier attempts to combine these data sets and suggests that improvements in the NASA Atmospheric CO2 Observations from Space (ACOS) retrieval algorithm have significantly improved the consistency of space-based and surface-based flux constraints

    An Ultra-Fast Metabolite Prediction Algorithm

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    Small molecules are central to all biological processes and metabolomics becoming an increasingly important discovery tool. Robust, accurate and efficient experimental approaches are critical to supporting and validating predictions from post-genomic studies. To accurately predict metabolic changes and dynamics, experimental design requires multiple biological replicates and usually multiple treatments. Mass spectra from each run are processed and metabolite features are extracted. Because of machine resolution and variation in replicates, one metabolite may have different implementations (values) of retention time and mass in different spectra. A major impediment to effectively utilizing untargeted metabolomics data is ensuring accurate spectral alignment, enabling precise recognition of features (metabolites) across spectra. Existing alignment algorithms use either a global merge strategy or a local merge strategy. The former delivers an accurate alignment, but lacks efficiency. The latter is fast, but often inaccurate. Here we document a new algorithm employing a technique known as quicksort. The results on both simulated data and real data show that this algorithm provides a dramatic increase in alignment speed and also improves alignment accuracy
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