58 research outputs found
Investigación comparativa de los contenidos de minerales, clorofila, composición de ácidos grasos y perfiles térmicos de hojas de olivo (Olea europaea L.) como subproducto
This work presents a chemical (the minerals, chlorophyll contents and fatty acids) and thermophysical investigation (DSC profile) of four varieties of olive leaves grown in Tunisia. The total chlorophy1l contents of olive leaves ranged from 1132.33 to 1795.93 ppm. The results showed that linolenic acid (C18:3) is the major fatty acid in olive leaves (from 30.02 to 42.16%), followed by oleic acid (C18:1) and palmitic acid (C16:0). The thermal profiles of olive leaf extracts determined by their DSC melting curves revealed simple thermograms with a single peak after melting. The hexane extract of the Chemchali variety, which contained relatively high unsaturated fatty acids and low saturated fatty acid levels, exhibited the lowest peak temperature value (54.59 °C) and required the smallest amount of energy for melting (31.57 J·g−1). This study showed that olive leaves possessed physicochemical properties and a fatty acid composition that may become interesting for industrial applications.Este trabajo presenta estudios de la composición quÃmica (minerales, contenido de clorofila y ácidos grasos) e inves tigaciones termofÃsicas ( perfil DSC) de cuatro variedades de hojas de olivo cultivadas en Túnez. Los contenidos totales de clorofila de las hojas de olivo oscilaron entre 1132,33 y 1795,93 ppm. Los resultados mostraron que el ácido linolénico (C18:3) es el ácido graso principal en las hojas de olivo (30,02 a 42,16%), seguido de los ácidos oleico (C18:1) y palmÃtico (C16:0). Los perfiles térmicos de los extractos de hoja de olivo determinados por sus curvas de fusion, DSC mostró termogramas simples con un solo pico después de la fusión. El extracto de hexano de la variedad Chemchali, que contenÃa ácidos grasos insaturados relativamente mas altos y bajos niveles de ácidos grasos saturados, exhibió el pico de temperatura más baja (54,59 °C) y requiere menor energÃa para la fusión (31,57 J·g−1). Este estudio mostró que las hojas de olivo poseen propiedades fisicoquÃmicas y composición en ácidos grasos que pueden ser interesantes para aplicaciones industriales
Optimization of coagulation-flocculation process for pastas industry effluent using response surface methodology
The goal of this study was to characterize and then optimize the treatment process of effluent generated from couscous and pasta industry. The crude effluent is characterized by a high level of organic concentration (from 2269 to 4383 mg/l). The optimization of coagulation-flocculation process was then performed to minimize chemical oxygen demand (COD). The experiments were carried out using the response surface methodology (RSM). A central composite design (CCD) was used to evaluate the effects and the interactions of three factors; coagulant dosage, flocculant dosage and pH on the wastewater treatment efficiency. Quadratic models was developed for the response variables and it successfully describes the experimental data (R2= 0.728). Analysis of variance (ANOVA) showed that only the coefficients corresponding to the flocculant dosage were significant (p < 0.0001). In order to take into account the variability of the initial organic concentration of the effluent, the CCD was repeated thrice by using a wastewater having initially different organic charges (530, 1775 and 2722 mg/l). Whatever was the initial organic charge of the wastewater, the optimal coagulant dosage was found constant (about 50 mg/l) and the optimal pH value was about 11.0. On the contrary, the optimal flocculant dosage varied linearly (from 24 to 50 mg/l) with the initial COD (from 529 to 2722 mg/l). These optimal conditions allow a COD removal varying from 78 to 93%. Irrigation and germination tests were carried out with treated and untreated wastewater and they showed that these effluents could be adequately recycled in culture irrigation.Key words: Couscous and pasta industry effluent, COD removal, central composite design, response surface methodology (RSM), irrigation tests
Comparison between bubbling and turbulent regime for the simulation of batch pharmaceutical powders fluidized bed drying
[EN] The two-phase theory has been frequently used to model fluidised bed drying. At high air velocities, a transition from the bubbling regime to the turbulent regime may occur. In this work, we compare a bubbling model and a turbulent model for the simulation of a two pharmaceutical powders drying in a pilot plant and an industrial plant fluidised bed. The bubbling model was based on a discrete variable bubble size. Heat and mass transfer coefficients were based on the Kunii and Levenspiel correlation [1]. Flow regime was supposed to be completely mixed for the emulsion phase. For the turbulent model, the bubble size is not anymore discrete but continuous and bubble phase is less distinguishable than in the bubbling regime. Heat and mass transfer were those proposed by Foka[2]. In addition, the freeboard section was considered since high entrainment is specific of this regime. Gas backmixing was taken into account by considering a plug flow with axial dispersion for the interstitial gas flow. The bubble phase being dilute, was modeled by a plug flow. A plug flow was also considered for the freeboard gas. The solid phase was supposed to be completely mixed. The bubbling regime simulation gave good agreement with experiment in the case of the pilot plant experiment, while the turbulent model better simulated the industrial scale experiment.Zammouri, A.; Boudhrioua Mihoubi, N.; Kechaou, N. (2018). Comparison between bubbling and turbulent regime for the simulation of batch pharmaceutical powders fluidized bed drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 457-464. https://doi.org/10.4995/IDS2018.2018.7703OCS45746
Semillas de Cucumis melo L. como prometedora fuente natural de aceite rico en sustancias biológicamente activas: composición, compuestos fenólicos y propiedades térmicas
This study aimed to evaluate the characteristic features, phenolic compounds and thermal analysis of melon seed oil (Maazoun variety), in order to determine its potential applications in food or pharmaceutical industries. The physicochemical properties of the seed oil revealed a high degree of unsaturation. The average contents of carotenoid and chlorophyll were 2.43 mg/kg and 5.70 mg/kg, respectively. The main fatty acids of melon seed oil were linoleic acid (68.98%) and oleic acid (15.84%), which makes this oil nutritionally valuable. Furthermore, trilinolein (LLL), accounted for 28.99% and constitutes the most abundant triacylglycerol. A chromatographic analysis showed that amentoflavone and luteolin-7-glycoside were the major phenolic compounds. A thermal analysis of melon seed oil was performed by differential scanning calorimetery (DSC). The results of sensorial properties indicated that melon seed oil is appreciated by tasters. The findings suggested that because of its composition, melon seed oil could be used successfully as an alternative source in the food and nutraceutical industries as a functional ingredient.El objetivo de este estudio fue la caracterización, evaluación de compuestos fenólicos y el análisis térmico del aceite de semillas de melón (variedad Maazoun), con el fin de conocer sus potenciales aplicaciones en la industria alimentaria o farmacéutica. Las propiedades fisicoquÃmicas del aceite de semilla mostraron un alto grado de insaturación. El contenido promedio de carotenoides y clorofila fue de 2,43 mg/kg y 5,70 mg/kg, respectivamente. Los principales ácidos grasos del aceite de semilla de melón fueron el linoleico (68,98%) y oleico (15,84%), lo que hace que este aceite sea nutricionalmente valioso. Además, la trilinoleÃna (LLL) que representó el 28,99% constituye el triacilglicerol más abundante. El análisis cromatográfico mostró que amentoflavona y luteolin-7-glucósido eran los principales compuestos fenólicos. El análisis térmico del aceite de semilla de melón se realizó mediante calorimetrÃa diferencial de barrido (DSC). Los resultados de las propiedades sensoriales indicaron que los catadores aprecian el aceite de semilla de melón. Los hallazgos sugieren que, debido a su composición, el aceite de semilla de melón podrÃa utilizarse con éxito como una fuente alternativa en la industria alimentaria y nutracéutica como ingrediente funcional
Thermodynamic properties and moisture sorption isotherms of two pharmaceutical compounds
[EN] This investigation examines and compares the water sorption isotherms and the thermodynamic properties of two pharmaceutical preparations (Hypril and Azix) intended to be manufactured with the same process plant and equipment. The moisture equilibrium isotherms were determined at 50, 60 and 70 °C using a gravimetric technique. Five isotherm models were explored for their fitting to the experimental data. Azix showed sigmoid type II isotherms while Hypril showed type III isotherms according to the BET classification. All investigated models fitted well the water sorption isotherms of Hypril. By contrast, only GAB and Adam and Shove equations gave appropriate fit to the experimental data of Azix. For both formulations, the isosteric heat and the differential entropy decreased sharply with the increase of equilibrium moisture content to minimum values and thereafter remain constant. In the case of Azix, the integral enthalpy decreased with equilibrium moisture content while the integral entropy increased until reaching a constant value. Contrariwise, Hypril showed decreasing of the integral enthalpy and entropy with the equilibrium moisture content.Zammouri, A.; Ben Zid, M.; Kechaou, N.; Boudhrioua Mihoubi, N. (2018). Thermodynamic properties and moisture sorption isotherms of two pharmaceutical compounds. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 449-456. https://doi.org/10.4995/IDS2018.2018.7702OCS44945
Contribution of plasmid-encoded peptidase S8 (PrtP) to adhesion and transit in the gut of Lactococcus lactis IBB477 strain
Etude de l’effet des conditions du séchage sur la texture et la couleur des filets de Sardina pilchardus
Le but de ce travail est d’étudier l’effet des conditions opératoires de séchage convectif par air chaud sur la couleur et la texture des filets de la sardine (Sardina pilchardus). Les filets de sardine ont été déshydratés par séchage convectif à vitesse d’air constante (Va = 1,5 m/s), différentes températures (40, 50 et 70°C) et à humidité relative d’air ambiante. Le critère final des expériences de séchage a été fixé de manière à avoir une teneur en eau finale des filets de l’ordre de 25% en base humide. La texture (mesure de la dureté par un texturomètre) et la couleur (paramètres L*a*b*) des filets ont été analysées à différents temps du séchage. L’évaluation des paramètres de qualité au cours du séchage (texture et couleur) montre que ces derniers dépendent de la teneur en eau du produit et des conditions de séchage. L’évaluation de latexture par le test de flexion trois points montre que l’augmentation de la température engendre une augmentation de la dureté des filets. Les paramètres L* et a* ont tendance à diminuer au fur et à mesure que la température de l’air augmente et la teneur en eau du produit chute. The aims of this work is the study of the effects of air drying process on the dehydration kinetics of sardine muscles (Sardina pilchardus).The effects of the air temperature (from 40 to 80°C) and the relative humidity (ambient and 40%) on the drying kinetics and on the color (L*a*b* parameters) and the textural (TAXT2i texturometer measurements)properties of the muscles were examined. Air drying kinetics were accelerated by increasing the air temperature and were attenuated by the humidification of drying air. The L* and a* parameters decreased with the increasing of air temperature. The injection of the moisture vapor on the air decreases this effect. The increasing of air temperature induced the hardness of the muscle and this effect was attenuated by moisture vapor’s injection. The moisture loss of the product induces a considerable decreasing of the muscle length
<em>Cucumis melo</em> L. seeds as a promising source of oil naturally rich in biologically active substances: compositional characteristics, phenolic compounds and thermal properties
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