Maher Trigui

The plant Carpobrotus edulis has traditionally been known for its wide applications in diseases, especially vitiligo, which is characterized by patches and white macules caused by the loss of melanocytes. One of the chemical treatments for vitiligo consists mainly of skin repigmentation and usually leads to a non-durable effect by inhibiting the Janus kinase (JAK) signal transduction (STAT pathway). JAK inhibitors generally block multiple JAK tyrosine kinases, which leads to secondary effects. In this study, natural molecules from Carpobrotus edulis were extracted and tested using a structure-based drug-design approach and pharmacophore modeling. The best-fit candidate from the extracted molecules was compared to the chemical molecules used. The results indicated a similarity between the chemical and natural ligands which suggested the potential use of the natural product against vitiligo. The main finding of this research work was the discovery of a new molecule extracted from a na...

ABSTRACT Rheological behavior of date syrup is an important factor affecting the efficiency of sugar production and refining processes such as boiling, crystallization, separation and pumping. A rotational viscometer was used to characterize the flow behavior of date syrup solution at four different temperatures (20 °C, 40 °C, 60 °C and 80 °C) and four concentrations (17, 24, 31 and 39 °Brix). The samples were subjected to a programmed shear rate increasing from 10 to 100 s−1 in 2 min, held constant at 100 s−1 for 10 min and linearly decreasing to 10 during 2 min. The power law model was fitted to shear stress vs. shear rate data to obtain the consistency coefficient (m) and the flow behavior index (n). Both m and n were sensitive to changes in temperature and concentration. The apparent viscosity increases with increasing concentration of date syrup and a decrease in temperature.

... Modular Feed Forward Networks to Predict Sugar Diffusivity from Date Pulp Part I. Model Validation. Authors: Trigui, Maher 1 ; Gabsi, Karim 1 ; Amri, Ines El 1 ; Helal, Ahmed Noureddine 2 ; Barrington, Suzelle 3. ... You are signed in as: Google (Institutional account). Group of ...

Les dattes de Phœnix dactylifera sont produites dans diverses regions du monde, elles sont reconnues comme etant un fruit de grande valeur nutritive.La majorite de production est localisee en Moyen-Orient et en Afrique du Nord. En Tunisie, la production a atteint en 2005/2006, 113000 tonnes par rapport a 4907283 tonnes de production mondiale.Les dattes representent un element tres important de point de vue energetique puisqu'elles renferment des teneurs importantes des carbohydrates, notamment le glucose et le fructose, interessantes a etre valorisees. L'objectif de ce present travail est donc: la mise au point d'un procede en continu permettant la valorisation des dattes par extraction est separation du glucose et du fructose.Un dispositif de laboratoire a ete mis au point et teste. Ce dispositif comprend trois etapes: Etape de diffusion.Etape d'hydrolyse du saccharose.Etape de separation du melange glucose - fructose. La faisabilite du dispositif a ete determinee c...

Four bulking agents, pine shavings, mixed (long and chopped) grass hay, chopped grass hay and long (whole) wheat straw, were each mixed with pig slurry and tap water to obtain three moisture contents (MC) of 60, 65 and 70%. Quadruplets of each treatment were placed in laboratory composting vessels with a capacity of 105l and a composting depth of 095m. Using the air plenum at the bottom of each vessel, air was forced at apparent velocities of 0-0002 m s -1 through each compost mass to measure the air static pressure drop across the compost mass as a function of apparent air velocity. Airflow resistance values were measured for compost depths ranging from 055 to 085 m. Following this test, all mixtures were aerated for 21 days of composting without overturning. The static pressure measurement procedure was then repeated on all quadruplet mixtures. The air static pressure drop was found with respect to a packed bed under laminar flow, defined using the particle size distribution, poro...

In North African countries, common or second quality dates are not harvested, but rather left to rot, although they are rich in fructose and glucose, sugars which offer more interesting nutritional properties than sucrose used as common table sugar. The recovery of fructose and glucose from these common dates requires the development of an efficient industrial process capable of separating both sugars. The objective of this study was therefore to test the Continuous Chromatographic Simulated Moving Bed technology (SMB) for the separation of both sugars from date syrup and the production of 90% High-Fructose-Syrup (HFS-90). Consisting of four adsorption columns, a laboratory SMB system was used to test the effect on separation of: date syrup sugar concentrations of 37, 26 and 22 %; Feed or syrup and Eluent or distilled water flow rate. After running 27 different combinations of operating parameters, the Feed and Eluent flow rates of 0.45 and 3.2 pore volume/h (pv/h), respectively, pr...

Many parameters involved in the bioproduction of fructose from date. These parameters can have significant effects on the yield and quality of the biopruduction of the high fructose date syrup (HFDS); they can be determined by either empirical or numerical investigations for the selected configurations; however, they are expensive procedures. The problem becomes more difficult if the aim is the inverse determination of the operating production process. This paper presents a predictive hybrid model based on the artificial neural networks (ANNs) and finite element method (FEM) that can be used for both forward and inverse prediction. The former is able to determine the diffusion rate, the bioconversion rate and the Fructose %at varying of process parameters, namely the date variety, the speeds of agitation, the date/water ratio, the initial concentration of glucose, the inoculum volume of biomass and the induction time of bioconversion process.The optimal ANN model was found to be a n...

Ohmic heating behaviour and electrical conductivity (EC) of two-phase food systems were studied. Food systems were comprised of a liquid phase using 4% w/w starch solution with 0.5% w/w salt, and a solid phase containing carrot puree and cubes of different sizes (6 and 13 mm) in different concentrations (30 and 50% w/w). A set of experiments was carried out

ABSTRACT In this study, diffusion process of sugar from date is modeled using a commercial computational fluids dynamics (CFD) code FLUENT 6.3.23 (Fluent Inc., USA). A two phases CFD model was developed using an Eulerian–Eulerian approach to calculate the date volume fraction transferred during time from date phase to water phase. The diffusion process was studied as function of three date varieties (Manakher, Lemsi and Alligue), three speeds of agitation (0, 50 and 100 rpm) and three date/water ratio (0.25, 0.50 and 0.75). The results revealed that, for mass transfer, the numerical data were in good agreement with the experimental data indicating the R2 of 0.84. Using a Lemsi date variety, the optimal condition of diffusion were 50 rpm and 0.75 for speed of agitation and date/water ratio respectively.

Physical and flow properties of proteins can provide information necessary for the optimal design of unit processes and quality control of the manufacturing process and final products. Therefore, the purpose of this investigation was to characterize the rheological behavior of a whey protein isolate (WPI) (BiPRO) dispersion as a function of pH and protein concentration. A rotational viscometer was used to determine the apparent viscosity, shear rate, and shear stress of WPI dispersions. Both the consistency index (k) and the flow behavior index (n) were sensitive to changes in pH and protein concentration. Mathematical relations obtained from experimental values of k and n allowed the determination of a model for apparent viscosity (eta) of WPI dispersions as a function of pH and protein concentration. At 5 and 10% BiPRO, whatever the pH, the rheological behavior appeared to be a newtonian fluid, while at 20% BiPRO, the rheological behavior appeared to be a nonnewtonian pseudoplastic fluid. Furthermore, at 20% Bipro, the apparent viscosity presented an increase in viscosity from 5.6 to 5.4, followed by a decrease from pH 5.4 to 5.0 at all shear rates. The highest viscosity was obtained at 20% pH 5.4, with an approximate value of 0.25 Pa.s, 10 times higher than the one obtained at 5 and 10% BiPRO.