Akram Hijazi

Capture of the Complex [Ni(dto)2]2– (dto2– = Dithiooxalato Ligand) in a Mo12 Ring: Synthesis, Characterizations, and Application toward the Reduction of Protons

The encapsulation of the complex [Ni(dto)(2)](2-) within an oxothiododecamolybdic cyclic cluster has been investigated. The resulting molybdenum ring, [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-), corresponds to the first example of the {Mo(2)O(2)S(2)}-based assembly arranged around a 3d transition-metal complex. It was unambiguously characterized in the solid state and in solution by FT-IR spectroscopy, single-crystal X-ray diffraction, NMR, UV-visible spectroscopy, and electrospray ionization-high-resolution mass spectrometry (ESI-HRMS). The latter technique revealed to be a powerful tool for the characterization of templated molybdenum ring systems in solution and gave excellent results in high resolution. The electronic spectrum of [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-) evidenced a strong red shift of the LMCT bands attributed to the complex [Ni(dto)(2)](2-), suggesting significant variations of the electronic properties upon its encapsulation within the Mo(12) ring. These differences were demonstrated by electrochemical studies in CH(3)CN, which also revealed, for both compounds [Ni(dto)(2)](2-) and [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-), electrocatalytic properties for the reduction of protons. These results evidence the ability of dithioxalato complexes to act as electrocatalysts for the hydrogen evolution reaction (HER) and confirm such a property for oxothiomolybdenum rings.

Two Compartmentalized Inner Receptors for the Tetramethylammonium Guest within a Keplerate-Type Capsule

The host-guest interactions between the spherical porous Keplerate anion, [Mo132O372(CH3CO2)30(H2O)72](42-) (abbreviated {Mo132}) and the tetramethylammonium cation have been investigated extensively by one- and two-dimensional (EXSY, ROESY, and DOSY) and variable-temperature NMR. Evidence of two inner receptor sites specific for a NMe4(+) guest appears consistent with a quite striking compartmentalization phenomenon. ROESY NMR analyses showed that both sites exhibit a close spatial proximity with the hanging inner acetate groups, while a quantitative EXSY study revealed that these two sites are differentiated by their exchange rates. These NMR data support the hypothesis that these two inner sites could be delimited by the hanging inner acetate groups forming triangular (S1) or pentagonal (S2) hydrophobic pockets on the inner side of the capsule wall. Furthermore, the stability constants associated with the trapping process of the NMe4(+) guest on both the S1 and S2 sites have been determined, showing that the stability constant of the S1 sites decreases significantly as the concentration of the capsule increases gradually, while that of the S2 sites remains nearly unaffected. Such an observation has been interpreted as a result of the plugging process of the {Mo9O9} pores by the counterions NH4(+), which causes unfavorable electrostatic interactions for the NMe4(+) coordination on the proximal S1 site. Finally, the thermodynamic parameters of the NMe4(+) transfer from the solvated situation to the interior of the capsule were estimated from variable-temperature NMR experiments that provide the split of the global process into two successive events corresponding to the plugging and transfer across the inorganic shell.

Protein Bread Fortification with Cumin and Caraway Seeds and By-Product Flour

Malnutrition continues to be a key health problem in developing regions. The valorization of food waste appears as an ideal way to prevent malnutrition and improve people’s access to food. Cumin (Cuminum cyminum L.) and caraway (Carum carvi L.) oilseeds are commonly used for cuisine and medicinal purposes. However, remaining cakes after oil extraction are usually underutilized. In order to assess the usefulness of these by-products in food applications, this study investigated the effect of their addition to protein bread formulations. Different levels (2, 4 and 6%) of whole seeds and cakes flour were used in the study. Fortified protein bread samples were compared to control protein bread and evaluated for their sensory, color, moisture, hardness properties, nutritional values as well as their biological activity. Results indicated that bread fortification shows a significant effect on bread properties depending on fortification level. A higher acceptability was observed specially for bread fortified with by-products flour. Increased tendencies of color darkness, moisture content, bread hardness, nutritional values as well as total phenolic content and radical scavenging activity compared to control bread were observed as the percentage of fortification increased in both cases. The overall results showed that the addition of cumin and caraway seeds and by-product flour can improve the antioxidant potential and overall quality of protein bread.

Effect of Addition of Fennel (Foeniculum vulgare L.) on the Quality of Protein Bread

Abstract Fennel (Foeniculum vulgare L.) is an aromatic plant belonging to Apiaceae family widely cultivated elsewhere for its strongly flavoured leaves and seeds. Fennel seeds are of particular interest as a rich source of both vegetable and essential oils with high amounts of valuable components. However, residual cakes after oil extraction were typically considered as byproducts, in the present framework, the potential added value of these cakes was studied. The aim of this study was to investigate the effect of addition of fennel cake and seeds to protein bread quality. In the current research, a single-screw extruder, which is a solvent-free technique, was used for fennel seed oil extraction. For the protein bread making, fennel seed and cake flour in concentrations from 1 to 6% were used. Moisture, colour L*a*b*, hardness, total phenolic concentration, DPPH radical scavenging activity, and nutritional value of protein bread were determined. The addition of fennel cake and seeds had significant (p < 0.05) effect on bread crumb colour and hardness attribute, whereby the bread became darker and harder in texture than the control. Moreover, higher antioxidant activity and total phenolic concentration were observed for both protein breads enriched with fennel cake and seed flour. The overall results showed that addition of fennel cake and seed had beneficial effects on phenolic concentration, antioxidant activity and quality of protein bread. This result suggests also that added value of fennel seeds oil by-products could be increased by their utilisation in bread production.

Evaluation of Nutritional and Technological Attributes of Whole Wheat Based Bread Fortified with Chia Flour

The aim of this study was to investigate and compare the effect of wheat bread fortification with varied levels (2%, 4%, and 6%) of chia seed powder (full fat) and cakes (defatted, residue after oil extraction). Chia flour was added to whole wheat bread rich in vital wheat gluten for the first time. The breadcrumbs were assessed for their antioxidant activity, nutritional content, textural properties, color, and sensory profiles. The addition of chia seed powder, particularly in high levels, was more effective in improving antioxidant activity compared to bread fortified with chia cakes. Bread supplementation with chia flour improves its nutritional value, especially in the case of chia cakes. A higher moisture content and lower hardness were observed after bread fortification, the influence was more evident with the defatted cake than with seed powder. Fortification with chia flour led to darker breads without significantly affecting their global acceptability. However, the fortified bread showed better values than control in terms of sensory profile. These results suggest that the addition of chia seed powder and defatted cake can enhance the overall whole wheat bread quality. Our results also highlight that bread making could be an unconventional alternative for the exploitation of defatted chia seed.

Bioadsorption of Pb2+ and Cu2+ on Eucalyptus Camaldulensis Leaves

Herein, the efficiency of Eucalyptus camaldulensis leaves as biosorbent for lead and copper was investigated. The particle size distribution was determined by Granulometric analysis and the functional groups were identified by FT-IR spectroscopy. The effects of contact time, pH and initial metal ions concentration were investigated. The experimental kinetic data were well fitted by the pseudo-second order kinetic model and Langmuir isotherm with a maximum adsorption capacity up to 71 mg g-1 and 37 mg g-1 for Cu2+ and Pb2+ respectively. The selectivity was examined in a binary ions solution where the adsorbent showed preference for lead over copper.

Removal of cadmium(II) ion from wastewater by using Lebanese Prunus avium stem as adsorbents

aDoctoral School of Science and Technology, Research Platform for Environmental Science (PRASE), Lebanese University, Lebanon, emails: nour.aliii2010@gmail.com (N. Al-Afy), hijazi_akram@hotmail.com (A. Hijazi), hasanrammal@hotmail.fr (H. Rammal), rabih.nehme@outlook.fr (R. Nehme), H.Annan@edst.edu.lb (H. Annan) bLaboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), LEADDER Laboratory, EDST, Lebanese University, Lebanon, emails: tayssir.hamieh@ul.edu.lb, tayssir.hamieh@univ-poitiers.fr (T. Hamieh), reda_mohamad75@hotmail.com (M. Reda), joumana.toufaily@ul.edu.lb (J. Toufaily) cSchool of Mechanical and Materials Engineering, Washington State University, Washington, DC, USA dInstitut de Chimie, des Milieux et des Matériaux de Poitiers, UMR CNRS 7285, Université de Poitiers 4, rue Michel Brunet TSA51106, B27, 86073 Poitiers cedex 9

REMOVAL OF HEAVY METALS FROM WASTE WATER BY USING A NATURAL AND BIODEGRADABLE ADSORBENT BASED ON PRUNUS AVIUM L. STEMS AS ADSORBENTS.

Ali Mcheik, Wassef El Khatib, Akram Hijazi*, Kamal Hariri, Mohamad Reda, Hassan Rammal Doctoral School of Science and Technology, Research Platform for Environmental Science (PRASE), Lebanese University, Lebanon. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

REMOVAL OF Pb(II) FROM WASTEWATERS BY ACTIVATED CARBON FROM LEBANESE CYMBOPOGON CITRATUS (LEMONGRASS): A COMPARATIVE STUDY

This study is made to prove the efficiency of the activated carbon (AC) of Lebanese Cymbopogon citratus in the adsorption of lead (Pb(II)) from aqueous medium. The adsorption was found to be dependent on initial metal ion concentration, pH of the solution, temperature, contact time and adsorbent dose. The maximum adsorption capacity was found for the concentration of 450 mg/L, pH 4, temperature 25 o C, contact time 2h, and adsorbent dose 1g. The equilibrium adsorption was better described by Freundlich isotherm model rather than Langmuir model. The kinetic data were better represented by the pseudo-second-order than the pseudo-first-order kinetic model. Thermodynamic studies showed that the process was exothermic and spontaneous. The results of this study reveal that the activated carbon (AC) of Lebanese Cymbopogon citratus is a very effective and environmentally friendly adsorbent, with low cost for Pb (II) removal.

Determination of the Total Phenolic content, Total Flavonoid Content, Antioxidant Activity and Some Bioactive compounds of the Lebanese Eryngium creticum L.

Polyphenolic compounds are bioactive substances widely distributed in the plant kingdom. They act as natural antioxidants and their presence contributes to the color, flavor, and aroma of food. Therefore, they are considered dietary antioxidants with interesting benefits to health. In this article the extraction of total phenolics, total Flavonoids and antioxidants activity from Eryngium creticum was determined after obtaining the plant extracts by conventional and non-conventional extraction techniques. Also this study aims to determine the bioactive constituents present in E. creticum extracts by using GC-MS method. The results obtained show that microwave assisted extraction is the best technique used for the extraction of phenolic compounds and flavonoids from E. creticum giving a yield of 34.46 µg/mL and 21.05 µg/mL respectively. However, the antioxidants activity, evaluated by the DPPH assay was low in all the extraction techniques. Also the results showed the presence of 9 fatty acid derivatives, most of them have therapeutic effects on human health. These results explain the use of E. creticum in traditional medicine to treat various diseases.