Evaluación de cáscaras de maní como alternativa a arcillas decolorantes

Peanut hulls (PNH) were carbonized at different temperatures, times, and evaluated at different concentrations as an alternative to bleaching clays. Evaluation of bleached crude soybean oil with PNH was based on their delta free fatty acids, reduction in peroxide value (PV), reduction in phospholipids (PL) and bleachability. The performance of several commercially used bleaching clays was evaluated, for comparison. Mixtures were formulated including: PNH and Tonsil -N (TN), PNH and Fuller’s earth (FE) and PNH and O-passive (OP) and examined. The oxidative stability of oils was determined. Results for the investigated commercial bleaching clays revealed: TN > FE > F > TF > OP. Highest reduction in PV and PL, and highest bleachability were achieved for soybean oil bleached with 2% PNH carbonized at 500°C for 30 min (PNH”). Mixtures of PNH” with the three chosen bleaching clays indicated that 1PNH”: 2TN gave the highest bleachability. CSO was miscella bleached in hexane using PNH” and resulted in an appreciable improvement in all oil characteristics, especially in bleachability. Oxidative stability of oils was in the following order: TN > control > FE > PNH” with Induction period values of 23,1 > 6,43 > 5,73 > 2,85 h, respectively.Las cáscaras de maní (PNH) fueron carbonizadas a diferentes temperaturas y tiempos, y utilizadas a diferentes concentraciones como una alternativa a las tierras decolorantes. La evaluación de un aceite de soja decolorado con PNH se ha basado en sus ácidos grasos libres, reducción del índice de peróxidos (PV), reducción de los fosfolípidos (PL), y en la blanqueabilidad. El rendimiento de varias tierras decolorantes de uso comercial fue evaluado y comparado con el de PNH carbonizada. Las mezclas formuladas incluían: PNH y Tonsil-N (TN), PNH y tierras de Fuller (FE) y PNH y O-pasivo (OP). La estabilidad oxidativa de los aceites resultantes fue determinada. Los resultados revelaron que la efectividad de la decoloración con las tierras decolorantes investigadas fue el siguiente: TN > FE > F > TF > OP. La mayor reducción en PV y PL, y la mayor decoloración se logró para el aceite de soja blanqueado con un 2% de PHN carbonizada a 500°C durante 30 min (PNH”). Las mezclas de PHN” con las tres tierras de blanqueo elegidas indicaron que 1PHN”: 2TN dio el mayor porcentaje de decoloración. La miscela de aceite de soja crudo en hexano decolorada usando PNH” resultó mejorar apreciablemente todas las características del aceite, sobre todo la blanqueabilidad. La estabilidad oxidativa fue en el siguiente orden: TN > control > FE > PNH” con valores de periodo de inducción de 23,1 > 6,43 > 5,73 > 2,85 h, respectivamente

Tocoferoles y flavonoides de halofito SOS-7

Halophyte is an oil seed coded as SOS-7 (Salicomia Oil Seed, 7th year of selection). Tocopherol constituents of SOS-7 halophyte oil were determined directly in the oil by using high pressure liquid chromatography coupled to fluorescence detector. It was found that the oil contains 710 ppm total tocopherols. The tocopherol constituents, alpha, beta, gamma and delta, were found at the level of 38.2,1.0, 58.7 and 2.1% respectively. Nine flavonoid glycosides were isolated and identified from the seeds and it was found that they belong to the flavonol class of flavonoids. These flavonol compounds were identified as: quercetin-3, 7-diglucoside, quercetin-3-glucoside-7-galactoside, quercetin-3-sophoroside, quercetin-3-glucoside, quercetin-3-galactoside, isorhamnetin-3, 7-di-glucoside, isorhamnetin-3-glucoside, kaempferol-3, 7-diglucoside and kaempferol-3-glucoside.Halofito es una semilla oleaginosa codificada como SOS-7 (semilla oleaginosa Salicomia, séptimo año de selección). Los tocoferoles del aceite de halofito SOS-7 fueron determinados directamente en el aceite usando cromatografía líquida de alta presión acoplada a detector fluorescente. Se encontró que el aceite contenía 710 ppm de tocoferoles totales. Los tocoferoles alfa, beta, gamma y delta, se encontraron a niveles de 38.2,1.0, 58.7 y 2.1%, respectivamente. Nueve glicósidos flavonoides fueron aislados e identificados de las semillas y se encontró que pertenecen a la clase flavonol dentro de los flavonoides. Estos flavonoles fueron identificados como: quercetina-3,7-diglucosido, quercetina-3-glucosido-7-galactosido, quercetina-3-soforosido, quercetina- 3-glucosido, quercetina-3-galactosido, isorannetina-3, 7-di-glucosido, isorannetina-3-glucosido, kampferol-3, 7-diglucosido y kampferol-3-glucosido

Estudios sobre los constituyentes lipídicos de semillas de uva recuperadas de la pulpa resultante del procesado de uva blanca

Studies on the lipid constituents of grape seeds, produced as by-product from white grape processing, were carried out. Gas liquid chromatography was used to determine the composition of fatty acid methyl esters and sterol silyl derivatives of the oil. The oil was found to contain appreciable amount of unsaturated fatty acids, namely, oleic and linoleic acids, however, linolenic acid was not detected. Saturated fatty acids, namely, palmitic and stearic were found to be present in reasonable amounts. Myristic, palmitoleic, eicosanoic and eicosadienoic acids were detected as minor components. Isofucosterol was found among the other sterol constituents namely, campesterol, stigmasterol and beta-sitosterol. HPLC analysis of the oil for determination of tocopherols, showed the presence of alpha-and gamma-tocotrienols, and alpha-and gamma-tocopherols to the extent of 53.2, 28.6, 16,4 and 1,8% respectively. The total tocopherols content of the oil was 470 ppm. The defatted meal of grape seeds was found to contain 24,6% protein which contained large proportions of all the essential amino acids as determined by amino acid analyzer.Se han realizado estudios sobre los constituyentes lipidiaos de semillas de uva producidas como subproducto del procesado de uva blanca. La cromatografía gas-líquido se usó para determinar la composición de esteres metílicos de ácidos grasos y silil derivados esteroles del aceite. Se observó que el aceite contenía cantidades apreciables de ácidos grasos insaturados, principalmente ácidos oleico y linoleico, no siendo sin embargo detectado el ácido linolénico. Se encontraron en cantidades razonables ácidos grasos saturados, principalmente, palmítico y esteárico. Como componentes minoritarios se detectaron los ácidos mirístico, palmitoleico, eicosanoico y eicosadienoico. El isofucosterol apareció junto a otros esteroles, principalmente, campesterol, estigmasterol y beta-sitosterol. El análisis por HPLC del aceite para la determinación de tocoferoles, mostró la presencia de alfa- y gamma-tocotrienoles, y alfa- y gamma- tocoferoles en cantidades de 53'2, 28'6, 16'4 y 1'8 respectivamente. El contenido en tocoferoles totales del aceite fue de 470 ppm. En la harina desgrasada de semillas de uva se vio un contenido del 24'6% en proteína, con amplias proporciones de todos los aminoácidos esenciales, determinados mediante analizador de aminoácidos

Strengthening of Concrete Beams Using FRP Composites

Finite element analysis (FEA) is used to predict the behavior of reinforced concrete beams strengthened with fiber reinforced polymer (FRP). To verify and measure the accuracy of the FEM model, the current model results were compared with both experimental and theoretical available results. Four beams were studied simulating the Horsetail Creek Bridge, Oregon, USA. The first one is a control beam with no strengthening fiber.The second beam is strengthened with carbon fiber reinforced polymer (CFRP) oriented along the length of the beam to reinforce the flexure behavior. The third beam is wrapped with glass fiber reinforced polymer(GFRP) laminates representing the shear beam. The fourth one is strengthened with CFRP and GFRP laminates representing the flexure-shear beam.The load-strain for concrete, steel and fiber as well were represented and compared. In addition, the load deflection curves and crack patterns were developed and represented. The results showed that the modeling process was accurate in simulating the tested beams. It was also clear that using FRP in strengthening reinforced concrete beams is an effective method in improving both shear and flexural behavior of the beams

Nuevas tendencias en la determinación de la autenticación de aceite de maíz.

HPLC analysis of triacylglycerols and minor components, such as free and acylated sterols, and sterylglycosides, tocopherols and ¡soprenoid alcohols, have been employed for establishing oil authenticity. GLC analysis of the whole sterols as their TMS - derivatives has been also conducted. Genuine oils, namely, rapeseed, sunflower and corn oil as well as corn oil admixtures with the two oils were analyzed. Triacylglycerols and tocopherols were directly determined in the oils whereas the four sterol in lipids (free and acylated sterols and sterylglycosides) and isoprenoid alcohols were isolated and derivatized into their anthroyi nitrile derivatives. It was concluded that the analysis of minor components in combination with triacylglycerols is more advantageous for authentication of corn oil. However, ¡soprenoid alcohols are more decisive in this respect. Natural variability of the components in the oils from different origins can modify the detection limits.Para establecer la autenticación del aceite se ha utilizado la cromatografía líquida de alta eficacia de triacilgliceroles y componentes menores tales como los esteróles y esterilglicosidos libres y acilados, tocoferoles y alcoholes isoprenicos. También se ha llevado a cabo el análisis por cromatografía gas-líquido de los esteróles totales así como de sus derivados silanizados. Se analizaron aceites genuinos de colza, girasol y maíz así como mezclas de aceites de maíz con los otros dos aceites. Se determinaron directamente los triacilgliceroles y tocoferoles en los aceites mientras que los cuatro lipidos esterólicos (esteróles y esterilglicosidos libres y acilados) y alcoholes isoprenicos se aislaron y se transformaron en sus antroil nitril derivados. Se concluyó que el análisis de los componentes menores en combinación con el de los triacilgliceroles es más ventajoso para la autenticación del aceite de maíz. Sin embargo a este respecto son más decisivos los alcoholes isoprenicos. La variabilidad natural de los componentes en los aceites de diferentes orígenes puede modificar los límites de decisión

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole

Interaction of RNA polymerase II and the small RNA machinery affects heterochromatic silencing in Drosophila

<p>Abstract</p> <p>Background</p> <p>Heterochromatin is the tightly packaged dynamic region of the eukaryotic chromosome that plays a vital role in cellular processes such as mitosis and meiotic recombination. Recent experiments in <it>Schizosaccharomyces pombe </it>have revealed the structure of centromeric heterochromatin is affected in RNAi pathway mutants. It has also been shown in fission yeast that the heterochromatin barrier is traversed by RNA Pol II and that the passage of RNA Pol II through heterochromatin is important for heterochromatin structure. Thus, an intricate interaction between the RNAi machinery and RNA Pol II affects heterochromatin structure. However, the role of the RNAi machinery and RNA Pol II on the metazoan heterochromatin landscape is not known. This study analyses the interaction of the small RNA machinery and RNA Pol II on <it>Drosophila </it>heterochromatin structure.</p> <p>Results</p> <p>The results in this paper show genetic and biochemical interaction between RNA Pol II (largest and second largest subunit) and small RNA silencing machinery components (<it>dcr-2, ago1, ago2, piwi, Lip [D], aub </it>and <it>hls</it>). Immunofluorescence analysis of polytene chromosomes from trans-heterozygotes of RNA Pol II and different mutations of the small RNA pathways show decreased H3K9me2 and mislocalization of Heterochromatin protein-1. A genetic analysis performed on these mutants showed a strong suppression of <it>white-mottled4h </it>position effect variegation. This was further corroborated by a western blot analysis and chromatin immunoprecipitation, which showed decreased H3K9me2 in trans-heterozygote mutants compared to wild type or single heterozygotes. Co-immunoprecipitation performed using <it>Drosophila </it>embryo extracts showed the RNA Pol II largest subunit interacting with Dcr-2 and dAGO1. Co-localization performed on polytene chromosomes showed RNA Pol II and dAGO1 overlapping at some sites.</p> <p>Conclusion</p> <p>Our experiments show a genetic and biochemical interaction between RNA Pol II (largest and second largest subunits) and the small RNA silencing machinery in <it>Drosophila</it>. The interaction has functional aspects in terms of determining H3K9me2 and HP-1 deposition at the chromocentric heterochromatin. Thus, RNA Pol II has an important role in establishing heterochromatin structure in <it>Drosophila</it>.</p