Bachar Zebib

University of Toulouse, Tolosa de Llenguadoc, Midi-Pyrénées, France

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Publications (14)33.37 Total impact

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    ABSTRACT: Satureja myrtifolia (Boiss. & Hohen.) Greuter & Burdeta medicinal plant belonging to the Lamiaceae family was collected from south of Lebanon and hydro-distilled by Clevenger method. Essential oil composition from aerial parts was analyzed by GC-MS technique. The odor of essential oil is characteristic, and clear yellow liquid oil was obtained after hydro-distillation. The yield of the essential oil was 1.25±0.02 % of dry matter (w/w). Thirty nine volatile components were identified in the Satureja myrtifolia oil, which shows a high amount of hydrocarbons class (57.82±0.1 %). Other classes were also identified such assesquiterpene hydrocarbons (12.96±0.1 %), oxygenated sesquiterpenes (10.65±0.2 %), phenolic compounds (10.32±0.1 %), acids (5.53±0.1 %), and monoterpenes hydrocarbons (2.21±0.1 %).In addition, a comparison with the unique study performed on Satureja myrtifolia was also carried out.
    Full-text · Article · Apr 2015 · Journal of essential oil-bearing plants JEOP
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    ABSTRACT: The invention relates to a method for the synthesis of acylglycerol oligomers, characterised in that it comprises reacting: at least one precursor selected from the group formed by cyclic carbonic esters of α/α'-acylglycerol having general formula (IV) (Formula); at least one metal catalyst selected from the group formed by metal cation salts, organometallic compounds and metal oxides; and at least one organic primer selected from the group formed by hydroxyl organic compounds, at a reaction temperature below 220° C.
    No preview · Patent · Sep 2014
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    ABSTRACT: Economic and technical problems related to the reduction of petroleum resources require the valorisation of renewable raw material. Recently, microalgae emerged as promising alternative feedstock that represents an enormous biodiversity with multiple benefits exceeding the potential of conventional agricultural feedstock. Thus, this comprehensive review article spots the light on one of the most interesting microalga Chlorella vulgaris. It assembles the history and a thorough description of its ultrastructure and composition according to growth conditions. The harvesting techniques are presented in relation to the novel algo-refinery concept, with their technological advancements and potential applications in the market.
    Full-text · Article · Jul 2014 · Renewable and Sustainable Energy Reviews
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    ABSTRACT: The microalgal structure has been investigated to evaluate the release of proteins in aqueous media from five microalgae after conducting different cell disruption techniques: manual grinding, ultrasonication, alkaline treatment, and high-pressure treatment. After conducting cell disruption, the protein concentration in water was determined for all the microalgae and the results are discussed within the context of their cell wall structure. It was found that the aqueous media containing most protein concentration followed the order: high-pressure cell disruption > chemical treatment > ultrasonication > manual grinding. Fragile cell-walled microalgae were mostly attacked according to the following order: Haematococcus pluvialis < Nannochloropsis oculata < Chlorella vulgaris < Porphyridium cruentum ≤ Arthrospira platensis .
    Full-text · Article · Dec 2013 · Algal Research
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    ABSTRACT: Residues obtained after isolating essential oil very often constitute more than 99% of the total raw material. Such residues are poorly exploited although they may represent a potential sustainable source for valuable natural products. This study investigated antioxidant properties and the composition of bioactive compounds (total phenolics, flavonoids, flavonols) present in the deodorized extracts of Tussilago farfara flowers and stems collected in Lithuania and South of France, which were isolated with acetone, methanol or ethanol. Online HPLC/UV/DPPH scavenging assay showed that among 8 identified by HPLC/MS compounds, dicaffeoylquinic acids and quercetin pentoside were the major radical scavengers in the T. farfara extracts.
    No preview · Article · May 2013 · Records of Natural Products
  • Bachar Zebib
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    ABSTRACT: A novel mesoporous material, named LRS-2, was obtained by isomorphic Al substitution and delamination of a naturally occurring kenyaite silicate layer. Delamination procedure consisting of kenyaite layers exfoliation with cetyltrimethylammonium [C16H33(CH3)3N+] alkyl chain in the presence of tetrapropylammonium hydroxide, followed by sonication step, and calcination at 700 °C to remove the organics. After delamination, surface area of LRS-2 material was increased by a factor of ca. 12.5 (30 vs. 377 m2 g−1) consisting mostly in highly accessible external surface. Its good activity for the test reaction of cumene cracking was compared of zeolitic catalyst, H-ZSM5, and it constitutes a promising ecofriendly candidate for the cracking of larger hydrocarbons.
    No preview · Article · Mar 2013 · Journal of Inorganic and Organometallic Polymers and Materials
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    ABSTRACT: The chemical composition of essential oils of sweet cicely (Myrrhis odorata (L.) Scop.) leaves from two geographic areas (Lithuania and France) were determined by gas chromatography/mass spectrometry (GC/MS). Comparatively slight differences were observed in the chemical composition of essential oils from both selected origins. The yield of essential oil varied from 0.4±0.02% in Lithuanian to 0.5±0.01% in French origin. In total twenty and twenty-six components were identified in the hydrodistilled oils of Lithuanian and French origin, respectively. The essential oils of both origins were found to be rich in E-anethole (48.1±1.4% and 50.7±1.1%), methyleugenol (14.3±0.5% and 13.1±0.4%), E-nerolidol (10.2±0.8% and 12.0±0.3%) and germacrene-D (5.0±0.1% and 4.3±0.3%).
    No preview · Article · Feb 2013 · Journal of Essential Oil Research
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    ABSTRACT: BACKGROUND: Today, few known plant species provide both an essential oil (EO) and a vegetable oil (VO). Seed and husk of two Aframomum species were investigated and compared in terms of EO, fatty acids, tocopherols, and tocotrienols. RESULTS: EO yield reaches 15.3 g kg−1 in the seeds and 3.2 g kg−1 in the husks, while VO yield is 180.0 g kg−1 in the seeds and 25.0 g kg−1 in the husks. β-Pinene, 1,8-cineol, α-selinene, terpine-4-ol, linalool, myrtenal and β-caryophyllene are the major compounds of seed and husk EO. Fatty acid analysis of two Aframomum species shows that oleic, linoleic, and palmitic acids were the major compounds of VO. Total sterol contents reached 4.3 g kg−1 in seed VO and 8.5 g kg−1 in husk VO. An appreciable amount of tocopherols (0.52 g kg−1) was found in seed VO. CONCLUSION: The seed and husk oil of A. stipulatum and A. giganteum fruits are rich sources of many bioactive constituents such as fatty acids, sterols, tocopherols and tocotrienols. These tropical wild fruits can be considered as new Aroma Tincto Oleo Crops (ATOC) resources that contain both EOs and VOs. Copyright
    No preview · Article · Jan 2013 · Journal of the Science of Food and Agriculture
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    ABSTRACT: In order to release proteins in the aqueous phase, high-pressure homogenization and alkaline treatments were applied to rupture the cell walls of five intensively grown microalgae. Protein characterisation was carried out by analysing the amino acid profiles of both the crude microalgae and the protein extracts, obtained after both types of treatment. The results showed that the proportion of proteins released from microalgae following both treatments was, in descending order: Porphyridium cruentum > Arthrospira platensis > Chlorella vulgaris > Nannochloropsis oculata > Haematococcus pluvialis, reflecting the increasingly protective, cell walls. Nonetheless, mechanical treatment released more proteins from all the microalgae compared to chemical treatment. The highest yield was for the fragile cell walled P. cruentum with 88% hydro-soluble proteins from total proteins, and the lowest from the rigid cell walled H. pluvialis with 41%. The proportion of essential and non-essential amino acids in the extract was assessed and compared to the crude microalgae profile. It was higher after alkaline treatment and much higher after high-pressure homogenization. These results suggest that non-essential amino acids are more concentrated actually inside the cells and that different types of proteins are being released by these two treatments.
    Full-text · Article · Jan 2013 · Algal Research
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    ABSTRACT: The purpose of present study was to stabilize curcumin food pigment by its complexation with divalent ions like (Zn(2+), Cu(2+), Mg(2+), Se(2+)), in "green media" and evaluate its stability in vitro compared to curcumin alone. The curcumin complexes were prepared by mechanical mixture of curcumin and sulfate salts of each metal (metal : curcumin 1/1mol) into unconventional and nontoxic glycerol/water solvent. Two stoichiometry of complex were obtained, 1 : 1 and 1 : 2 (metal/curcumin), respectively. On evaluation of in vitro stability, all complexes were found to provide a higher stability from curcumin alone.
    Full-text · Article · Jun 2010 · Bioinorganic Chemistry and Applications
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    ABSTRACT: The condensation of technical-grade oleic acid (OA) (65%, 85%, and 90% oleic acid) with glycidol (Gly) was carried out in an aqueous medium in the presence of a macroporous anion-exchange resin containing ammonium groups. The reaction was optimized by a unifactorial method and by a 2n−1 fractional factorial plan. The effects of the following main parameters were quantified from experiments based on a 2(5−1) = 24 factorial design: OA/Gly molar ratio, concentration (mmol of OA/mL of H2O), catalytic efficiency (mequiv of X/mmol of OA), and temperature. The conditions were optimized for a discontinuous process in a stirred reactor for selective synthesis of glycerol 1-monooleate (1-GMO) in a polymorphic system (solid resin/emulsion or microemulsion) consisting of OA/Gly/H2O/1-GMO. The catalytic role of the Ambersep 900−X resin was demonstrated by conducting the reaction using the resin in the different functional forms Ambersep 900−OH− and Ambersep 900−HCO3− and in the nonfunctionalized form Ambersep 900−Cl−. The highest yield of 1-GMO (97%) was obtained with the nonfunctionalized form Ambersep 900−Cl− at 70 °C.
    No preview · Article · Aug 2009 · Industrial & Engineering Chemistry Research
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    ABSTRACT: Well-crystallized samples of the phyllosilicate magadiite have been synthesized in their sodic form, both purely silicic and with an Al/Si ratio of 30. They have been delaminated by a procedure consisting of CTMA+ swelling in the presence of TPAOH, sonication, and calcination at 700°C to remove the organics, and characterized by XRD, 27Al and 29Si NMR, IR, TEM and SEM, and N2 physisorption after the successive steps of this procedure. The final delaminated solids, consisting of crumpled sheets, exhibit a high (500-510 m2/g), mostly external surface area. While 29Si NMR indicated some loss of structural order, IR suggested the preservation of a typical feature of the magadiite sheets, namely 5-membered (TO4) rings. The acidity of the delaminated Al-containing material was evaluated by low-temperature CO adsorption. This technique revealed strong Brönsted acidic centers, whose behavior was similar to that of Si-OH-Al bridging hydroxyls in pentasil zeolites. Finally, the catalytic activity was evaluated for the test reaction of cumene cracking, and shown to be much higher than that of a reference silica alumina. These results make delaminated magadiite an attractive candidate for use as a novel acid catalyst or catalytic support.
    No preview · Article · Jan 2006
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    ABSTRACT: Two routes for the preparation of high surface area silica-alumina materials with strong Brønsted acidity and open porosity are examined: one uses the organisation of β-zeolite seeds with surfactant micelles, and the other the delamination of Al-Magadiite, a naturally occurring sodium phyllosilicate. The textures, of these materials are characterised using N2-sorption and the localisation of most of the Al in tetrahedral substitution in the silica, framework is shown using 27Al MAS NMR. These two materials show good activity for the cracking of cumene. Furthermore, the characterization of their acidity by FTIR of adsorbed CO reveals the presence of strong and medium Brønsted acid sites.
    No preview · Article · Dec 2005 · Studies in surface science and catalysis
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    ABSTRACT: Well-crystallized samples of the phyllosilicate magadiite have been synthesized in their sodic form, both purely silicic and with an Al/Si ratio of 30. They have been delaminated by a procedure consisting of CTMA+ swelling in the presence of TPAOH, sonication, and calcination at 700 °C to remove the organics and characterized by XRD, 27Al, and 29Si NMR, IR, TEM, and SEM, and N2 physisorption after the successive steps of this procedure. The final delaminated solids, consisting of crumpled sheets, exhibit a high (500−510 m2/g), mostly external surface area. While 29Si NMR indicated some loss of structural order, IR suggested the preservation of a typical feature of the magadiite sheets, namely, five-membered (TO4) rings. The acidity of the delaminated Al-containing material was evaluated by low-temperature CO adsorption. This technique revealed strong Brönsted acidic centers, whose behavior was similar to that of Si−OH−Al bridging hydroxyls in pentasil zeolites. Finally, the catalytic activity was evaluated for the test reaction of cumene cracking and shown to be much higher than that of a reference silica alumina. These results make delaminated magadiite an attractive candidate for use as a novel acid catalyst or catalytic support.
    No preview · Article · Dec 2005 · Chemistry of Materials