91 research outputs found

    Colour assessment on bread wheat and triticale fresh pasta

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    Although durum wheat is the cereal of choice for pasta production, in many areas of Argentina pasta is made from bread wheat, since durum wheat is cultivated only in a small region of the country. The purpose of this work was to determine the influence of different bread flours on the colour of laminated fresh pasta. Triticale flour was also studied. In addition, ash, protein, and protein fractions of each flour were measured. Also, the formulation was modified using different gluten, starch, and water concentrations. Pasta lightness and redness were affected mainly by the ash content, while yellowness was affected by the protein content of different flours. A similar effect was found when the formulation was substituted for starch and gluten, due to protein dilution and concentration, respectively. Albumins and globulins correlated with a* component, while gliadins, soluble and insoluble glutenins correlated with b* component; however, only glutenins presented correlation with colour score (CS = [L* + (b*×2)]/20). The greatest amount of water added to the dough produced a decrease of lightness and an increase of redness and yellowness of pasta samples. The overall ANOVA revealed that the greatest sources of variation for pasta colour were the different flours used, in comparison with the effect of starch and gluten substitution, and with the addition of different amounts of water.Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Colour assessment on bread wheat and triticale fresh pasta

    Get PDF
    Although durum wheat is the cereal of choice for pasta production, in many areas of Argentina pasta is made from bread wheat, since durum wheat is cultivated only in a small region of the country. The purpose of this work was to determine the influence of different bread flours on the colour of laminated fresh pasta. Triticale flour was also studied. In addition, ash, protein, and protein fractions of each flour were measured. Also, the formulation was modified using different gluten, starch, and water concentrations. Pasta lightness and redness were affected mainly by the ash content, while yellowness was affected by the protein content of different flours. A similar effect was found when the formulation was substituted for starch and gluten, due to protein dilution and concentration, respectively. Albumins and globulins correlated with a* component, while gliadins, soluble and insoluble glutenins correlated with b* component; however, only glutenins presented correlation with colour score (CS = [L* + (b*×2)]/20). The greatest amount of water added to the dough produced a decrease of lightness and an increase of redness and yellowness of pasta samples. The overall ANOVA revealed that the greatest sources of variation for pasta colour were the different flours used, in comparison with the effect of starch and gluten substitution, and with the addition of different amounts of water.Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Efecto de los parámetros del proceso de extracción por prensado sobre el rendimiento y la calidad de aceite de Pistacho

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    Pistachio nuts have high economical and nutritional value, mostly due to their elevated oil con­tent (50%), which is composed mainly of oleic and linoleic fatty acids. Box-Behnken experimental designs were performed to optimize the oil extraction by response surface analysis. The independent variables measured were seed moisture content (SMC), restriction die (RD), screw press speed (PS) and pressing temperature (PT), while the response variables considered were oil recovery (OR), fine solid contents in the oil (FSC), oil remain­ing in the cake (OC) and parameters related to oil quality (free fatty acid composition (FFAC, mg KOH/g oil), peroxide value (PV, meq O2/kg oil), K232, K270 and pigment contents, mg/kg oil). Given that the chemical quality of pistachio nut oil pressed under different conditions was not affected, the process response was optimized in order to maximize OR under two pressing temperatures. Therefore, at 75 °C, pistachio oil extraction showed a maximum OR (79.61 g/100 g oil) at 8% SMC, 4 mm RD and 20 rpm SP; while, under cold-pressed conditions, the maximum OR (65.97 g/100 g oil) was achieved at 10% SMC, 4mm RD and 20 rpm SP. It is important to highlight that OR values were higher than the results reported previously and the chemical quality parameters from both oils were in the range of Codex standards for virgin (non-refined) oils (FFAC < 0.31 and PV < 0.33).Los frutos de pistacho son altamente nutritivos, principalmente debido a su contenido de aceite (50%), compuesto principalmente por ácidos grasos mono y di-insaturados. Con la finalidad de conocer las condiciones de proceso adecuadas que permitan maximizar la cantidad de aceite extraído preservando la calidad química del mismo se utilizaron dos diseños experimentales de Box-Behnken. Las variables independientes analizadas fueron la humedad de la semilla (HS), el diámetro de reducción (DR), la velocidad y temperatura de prensado (VP y TP, respectivamente), mientras que las variables de respuesta fueron el rendimiento en aceite (RA), el contenido de sólidos finos en el aceite (CFA), el aceite remanente en torta (AT) y parámetros relacionados con la calidad (composición en ácidos grasos libres (CAGL, mg KOH/g aceite), índice de peróxido (IP, meqO2/kg aceite), K232, K270 y pigmentos (mg/kg aceite)). La calidad química de los aceites obtenidos no mostró daño oxidativo y/o hidrolítico significativo bajo las diferentes condiciones del proceso (IP< 0.33 y CAGL< 0.31, respectivamente), por lo tanto, la respuesta se optimizó para maximizar RA a dos TP, 75 y 40 °C. El rendimiento en aceite se maximizó ajustando HS (8% ó 10% b.h.), DR (4 mm), VP (20 rpm) a ambas temperaturas, alcanzando extracciones de aceite de 79.61% y 65.97%, respectivament

    Características tecnológicas de almidones de dos variedades de batatas (Ipomoea batatas [L.] Lam) infectadas con «encrespamiento amarillo»

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    El cultivo de batata se ve limitado por virosis y un complejo de siete virus, «encrespamiento amarillo» (EA), de alta incidencia en Argentina, provoca significativas disminuciones de rendimiento y calidad. En un ensayo experimental, con variedades Arapey INIA y Beauregard (sanas y enfermas con EA), se estimaron componentes de rendimiento (principalmente peso: PRC y número: NRC de raíces comerciales), rendimiento y característicastecnológicas de almidón como gelatinización y retrogradación (calorimetría diferencial de barrido) y viscosidad aparente de las pastas (analizador de viscosidad). Se analizó el comportamiento reológico de los geles de almidón, mediante resistencia a la compresión con analizador de textura, y se determinó distribución de tamaño de partícula. NRC y PRC fueron significativamente menores en plantas enfermas respecto a sanas (mermas de 81% para NRC en ambas variedades y 87% y 85,5% para PRC, en Beauregard y Arapey, respectivamente). EA no afectó al rendimiento de almidón, sin diferencias entre raíces sanas y enfermas de ambas variedades, aunque Arapey (9,00-10,05%) superó a Beauregard (6,23-8,06%). La entalpía de gelatinización del almidón resultó significativamente mayor en plantas enfermas de Beauregard que en sanas, sin diferencias en la temperatura de inicio de gelatinización entre ambos tratamientos, contrariamente a lo que sucedió en Arapey. El pico de viscosidad y la viscosidad final de los almidones fueron similares en plantas sanas y enfermas de ambas variedades, igual que la resistencia a la compresión de geles elaborados con almidones provenientes de plantas sanas y enfermas de ambos genotipos. Todas las muestras tuvieron una sola población de tamaño de partícula de almidón (rango: 5 -25 μm con pico cercano a 15 μm). En definitiva, EA no afectó la calidad tecnológica del almidón. Sin embargo, la disminución significativa de producción de raíces comerciales en plantas enfermas conllevó relevante reducción de la cantidad total de almidón por planta

    Colour assessment on bread wheat and triticale fresh pasta

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    Although durum wheat is the cereal of choice for pasta production, in many areas of Argentina pasta is made from bread wheat, since durum wheat is cultivated only in a small region of the country. The purpose of this work was to determine the influence of different bread flours on the colour of laminated fresh pasta. Triticale flour was also studied. In addition, ash, protein, and protein fractions of each flour were measured. Also, the formulation was modified using different gluten, starch, and water concentrations. Pasta lightness and redness were affected mainly by the ash content, while yellowness was affected by the protein content of different flours. A similar effect was found when the formulation was substituted for starch and gluten, due to protein dilution and concentration, respectively. Albumins and globulins correlated with a* component, while gliadins, soluble and insoluble glutenins correlated with b* component; however, only glutenins presented correlation with colour score (CS = [L* + (b*×2)]/20). The greatest amount of water added to the dough produced a decrease of lightness and an increase of redness and yellowness of pasta samples. The overall ANOVA revealed that the greatest sources of variation for pasta colour were the different flours used, in comparison with the effect of starch and gluten substitution, and with the addition of different amounts of water.Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Shear induced instabilities in layered liquids

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    Motivated by the experimentally observed shear-induced destabilization and reorientation of smectic A like systems, we consider an extended formulation of smectic A hydrodynamics. We include both, the smectic layering (via the layer displacement u and the layer normal p) and the director n of the underlying nematic order in our macroscopic hydrodynamic description and allow both directions to differ in non equilibrium situations. In an homeotropically aligned sample the nematic director does couple to an applied simple shear, whereas the smectic layering stays unchanged. This difference leads to a finite (but usually small) angle between n and p, which we find to be equivalent to an effective dilatation of the layers. This effective dilatation leads, above a certain threshold, to an undulation instability of the layers. We generalize our earlier approach [Rheol. Acta, vol.39(3), 15] and include the cross couplings with the velocity field and the order parameters for orientational and positional order and show how the order parameters interact with the undulation instability. We explore the influence of various material parameters on the instability. Comparing our results to recent experiments and molecular dynamic simulations, we find a good qualitative agreement.Comment: 15 pages, 12 figures, accepted for publication in PR

    Caracterización física y obtención de parámetros de fluidización de germen de trigo

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    El germen de trigo es el embrión del grano de trigo, presenta un elevado contenido de tocoferoles y proteínas y ácidos grasos y proteínas de alta calidad. A su vez, contiene enzimas con elevada actividad que limitan su periodo de aptitud a unos pocos días. El objetivo del presente trabajo fue caracterizar físicamente las partículas de germen de trigo para determinar los parámetros de diseño para un proceso de fluidificación térmica con aire. Los ejes principales de las partículas fueron determinados mediante análisis de imágenes y sus dimensiones y parámetros geométricos fueron calculados. La densidad de lecho fijo y la porosidad del lecho fueron determinadas. Los estudios fluido-dinámicos nos permitieron determinar los coeficientes, laminar (277,46±17,48) y turbulento (7,79±0,69) de la ecuación de Ergun y la velocidad de mínima fluidificación (0,35±0,02 m/s).Wheat germ is the embryo of de wheat seed, it contains a high tocopherol and protein content, and high quality proteins and fatty acids. Also, wheat germ has a considerable enzymatic activity that limits its shelf life. The aims of the study were to physically characterize wheat germ particles to determine their design parameters of thermal fluidization process with air. The principal axes of the particle were measured by image analysis, and their dimensions and geometric parameters were calculated. The fixed bed density and the void fraction were measured. The fluid-dynamic studies allowed us to determine laminar (277.46±17.48) and turbulent (7.79±0.69) coefficients of the Ergun equation and the minimum fluidization velocity (0.35±0.02 m/s).Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Three-dimensional pattern formation, multiple homogeneous soft modes, and nonlinear dielectric electroconvection

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    Patterns forming spontaneously in extended, three-dimensional, dissipative systems are likely to excite several homogeneous soft modes (≈\approx hydrodynamic modes) of the underlying physical system, much more than quasi one- and two-dimensional patterns are. The reason is the lack of damping boundaries. This paper compares two analytic techniques to derive the patten dynamics from hydrodynamics, which are usually equivalent but lead to different results when applied to multiple homogeneous soft modes. Dielectric electroconvection in nematic liquid crystals is introduced as a model for three-dimensional pattern formation. The 3D pattern dynamics including soft modes are derived. For slabs of large but finite thickness the description is reduced further to a two-dimensional one. It is argued that the range of validity of 2D descriptions is limited to a very small region above threshold. The transition from 2D to 3D pattern dynamics is discussed. Experimentally testable predictions for the stable range of ideal patterns and the electric Nusselt numbers are made. For most results analytic approximations in terms of material parameters are given.Comment: 29 pages, 2 figure

    Grafted Human Embryonic Progenitors Expressing Neurogenin-2 Stimulate Axonal Sprouting and Improve Motor Recovery after Severe Spinal Cord Injury

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    7 p.Background: Spinal cord injury (SCI) is a widely spread pathology with currently no effective treatment for any symptom. Regenerative medicine through cell transplantation is a very attractive strategy and may be used in different non-exclusive ways to promote functional recovery. We investigated functional and structural outcomes after grafting human embryonic neural progenitors (hENPs) in spinal cord-lesioned rats.Methods and Principal Findings: With the objective of translation to clinics we have chosen a paradigm of delayed grafting, i.e., one week after lesion, in a severe model of spinal cord compression in adult rats. hENPs were either naive or engineered to express Neurogenin 2 (Ngn2). Moreover, we have compared integrating and non-integrating lentiviral vectors, since the latter present reduced risks of insertional mutagenesis. We show that transplantation of hENPs transduced to express Ngn2 fully restore weight support and improve functional motor recovery after severe spinal cord compression at thoracic level. This was correlated with partial restoration of serotonin innervations at lumbar level, and translocation of 5HT1A receptors to the plasma membrane of motoneurons. Since hENPs were not detectable 4 weeks after grafting, transitory expression of Ngn2 appears sufficient to achieve motor recovery and to permit axonal regeneration. Importantly, we also demonstrate that transplantation of naive hENPs is detrimental to functional recovery.Conclusions and Significance: Transplantation and short-term survival of Ngn2-expressing hENPs restore weight support after SCI and partially restore serotonin fibers density and 5HT1A receptor pattern caudal to the lesion. Moreover, grafting of naive-hENPs was found to worsen the outcome versus injured only animals, thus pointing to the possible detrimental effect of stem cell-based therapy per se in SCI. This is of major importance given the increasing number of clinical trials involving cell grafting developed for SCI patients.This study was supported by the European Union FP6 "RESCUE" STREP; the "Institut pour la Recherche sur la Moelle Epiniere"; the "Academie de Medecine"; the "Societe Francaise de Neurochirurgie"; "Verticale" and the "Association Demain Debout Aquitaine". The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Neurogenic inflammation after traumatic brain injury and its potentiation of classical inflammation

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    Background: The neuroinflammatory response following traumatic brain injury (TBI) is known to be a key secondary injury factor that can drive ongoing neuronal injury. Despite this, treatments that have targeted aspects of the inflammatory pathway have not shown significant efficacy in clinical trials. Main body: We suggest that this may be because classical inflammation only represents part of the story, with activation of neurogenic inflammation potentially one of the key initiating inflammatory events following TBI. Indeed, evidence suggests that the transient receptor potential cation channels (TRP channels), TRPV1 and TRPA1, are polymodal receptors that are activated by a variety of stimuli associated with TBI, including mechanical shear stress, leading to the release of neuropeptides such as substance P (SP). SP augments many aspects of the classical inflammatory response via activation of microglia and astrocytes, degranulation of mast cells, and promoting leukocyte migration. Furthermore, SP may initiate the earliest changes seen in blood-brain barrier (BBB) permeability, namely the increased transcellular transport of plasma proteins via activation of caveolae. This is in line with reports that alterations in transcellular transport are seen first following TBI, prior to decreases in expression of tight-junction proteins such as claudin-5 and occludin. Indeed, the receptor for SP, the tachykinin NK1 receptor, is found in caveolae and its activation following TBI may allow influx of albumin and other plasma proteins which directly augment the inflammatory response by activating astrocytes and microglia. Conclusions: As such, the neurogenic inflammatory response can exacerbate classical inflammation via a positive feedback loop, with classical inflammatory mediators such as bradykinin and prostaglandins then further stimulating TRP receptors. Accordingly, complete inhibition of neuroinflammation following TBI may require the inhibition of both classical and neurogenic inflammatory pathways.Frances Corrigan, Kimberley A. Mander, Anna V. Leonard and Robert Vin
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