Institute Preparatoire aux Etudes Scientifiques et Techniques

Al Marsá, Tunisia

Institute Preparatoire aux Etudes Scientifiques et Techniques

Al Marsá, Tunisia
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Juan C.,University of Valencia | Berrada H.,University of Valencia | Manes J.,University of Valencia | Oueslati S.,Institute Preparatoire aux Etudes Scientifiques et Techniques
Food and Chemical Toxicology | Year: 2017

A study on raw barley and derived products (barley soup and beers) was carried out to determine the natural presence of twenty-four mycotoxins by both liquid chromatography and gas chromatography coupled to tandem mass spectrometry (MS/MS). The developed multi-mycotoxin procedure was based on both SLE and QuEChERS extraction steps. 66% of analyzed samples presented mycotoxin contamination and only one sample, which was soup of barley (6 ng/g), exceeded the maximum level (ML) established by EU for OTA (5 ng/g). Raw barley was the most contaminated matrix (62%), which concentrations ranged from 1.70 to 287.13 ng/g) and type of detected mycotoxins (DON, 15AcDON, NEO, NIV, HT2, FB1, OTA, ENA, ENA1, ENB and ENB1). DON was the most detected mycotoxin with an incidence of 56%, 29% and 23% in beer, soup of barley and barley, respectively. However, the highest levels detected were for ENA, in raw barley with 287 ng/g. In beer and soup of barley samples, the mycotoxins with highest level were 15AcDON (15.6 ng/g) and ENB1 (55.1 ng/g), respectively. Furthermore, 80% of positive soup of barley samples showed co-occurrence. No toxicological concern was associated to mycotoxins exposure for consumers. © 2017 Elsevier Ltd

Samti R.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | Raouafi F.,CNRS Institute of Chemistry | Chaouach M.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | Maaref M.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | And 4 more authors.
Applied Physics Letters | Year: 2012

Band structure calculations of complete InAs monolayer in AlGaAs/GaAs quantum wells are performed within the framework of the extended-basis sp 3d 5s * tight-binding model. We show that the optical properties can be tuned from the quantum well energy below the GaAs band-gap depending on the well thickness and the position of the probe. The results are supported by differential reflectivity measurements and represent a concept for optoelectronic devices with an operation wavelength widely tuneable around 850 nm employing GaAs process technology. © 2012 American Institute of Physics.

Ben Marzoug H.N.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | Ben Marzoug H.N.,INSA Val de Loire | Bouajila J.,CNRS Laboratory for Molecular and Photochemical Reactions | Ennajar M.,INSA Val de Loire | And 5 more authors.
Journal of Medicinal Food | Year: 2010

Essential oils of four different Eucalyptus species (Eucalyptus salubris, Eucalyptus salmonophloia, Eucalyptus oleosa, and Eucalyptus gracilis) grown in southern Tunisia were screened for their antioxidant and antimicrobial properties as well as their chemical compositions. According to gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analysis, chemical compositions of the Eucalyptus species E. salubris (27 compounds; 99.2%), E. salmonophloia (31 compounds; 99.2%), E. oleosa (32 compounds; 97.6%), and E. gracilis (18 compounds; 97.7%) were identified. In the 1,1-diphenyl-2-picrylhydrazyl assay, the antioxidant activity was in the range of 12.0-52.8 mg/mL, whereas in the 2,2′-azinobis-3- ethylbenzothiazoline-6-sulfonate assay, E. oleosa (176.5 ± 3.1 mg/L) gave the best inhibition result. To evaluate antimicrobial activity, all essential oils were tested against bacteria (two Gram-positive and two Gram-negative), two yeast, and two fungi. Essential oils exhibited an interesting antibacterial activity against all microorganisms tested (activity was better against Gram-positive bacteria) except for Staphylococcus aureus and Escherichia coli. Correlations between chemical composition and biological and antioxidant activities were studied. © Mary Ann Liebert, Inc.

Alarcon M.,United Nations Educational | Ben Lakhdar Z.,Tunis el Manar University | Culaba I.,Ateneo de Manila University | Lahmar S.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | And 4 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Based on physics education goals adopted at the 2005 World Conference on Physics and Sustainable Development, the workshop on "Active learning in optics and photonics (ALOP)" has been described as a model for teacher training and professional development. This paper describes the basic philosophy and elements of the workshop and how it has served physics teachers in schools and introductory college/university in the developing world. Its main philosophy of fostering modern hands-on learning techniques-- adapted to local culture, needs and availability of teaching resources-- is elaborated. The workshop provides the participants with a conceptual evaluation instrument, drawn from relevant physics education research, giving teachers an important tool to measure student learning. © 2010 SPIE.

Ellouze I.,Institute National Agronomique Of Tunisie | Ellouze I.,Institute Preparatoire Aux Etudes Scientifiques et Techniques | Debbabi H.,Institute National Agronomique Of Tunisie | Jamoussi B.,CNRS Institute of Chemistry | And 2 more authors.
Acta Horticulturae | Year: 2010

Sour orange Citrus aurantium L. is a well known tree as a Citrus rootstock, as well as for its flowers. These flowers are full of essential oil which are stored in essence glands. When they withdraw water-distillation they produce an essential oil Neroli as well as orange blossom water distillate. The present work focused on studying orange blossom water composition variation during extraction by steam distillation. A liquid-liquid extraction by hexane was applied on various orange blossom water fractions, and then a GC allowed analysing them. The qualitative study revealed that major components for all fractions are linalol and α-terpineol. Those two elements represent 80% of the total composition of the first fractions. In contrast, for the last ones, there is an important decrease in amounts of these components for linalyl acetate and terpinolene.

PubMed | Institute Preparatoire aux Etudes Scientifiques et Techniques, INNTA National Institute of Nutrition and Food Technology, Montpellier SupAgro and Hopital dEnfants
Type: Journal Article | Journal: Nutrients | Year: 2016

In the framework of a worldwide policy to eliminate iodine deficiency (ID) disorders, universal salt iodization was adopted in Tunisia two decades ago. The present study aims to evaluate this strategy, using both performance and impact indicators. A total of 1560 children, aged 6-12 years, were randomly sampled using a national, two-stage, stratified, cross-sectional cluster survey in 2012. Urinary iodine concentration (UIC) of the subjects, and household salt iodine content, were analyzed. The national median UIC was 220 g/L (95% confidence interval (CI): 199-241), indicating an acceptable iodine status at the population level. Only 11.4% (95% CI: 8.6-14.9) of the children had UIC <100 g/L, but with large regional disparities (4.3% to 25.5%,

Ellouze I.,CNRS Laboratory for Molecular and Photochemical Reactions | Ellouze I.,Institute Preparatoire aux Etudes Scientifiques et Techniques | Abderrabba M.,Institute Preparatoire aux Etudes Scientifiques et Techniques | Sabaou N.,Laboratoire Of Recherche Sur Les Produits Bioactifs Et La Valorisation Of La Biomasse | And 3 more authors.
Journal of Food Science | Year: 2012

Citrus aurantium leaves' essential oils (EOs) were evaluated for chemical composition and antioxidant and antibacterial activities. The vegetable material, taken 5 times during the year, has undergone the hydrodistillation to prepare EO. Chemical characterization by gas chromatography/mass spectrometry and GC/flame ionization detection allowed the identification of 46 compounds, and a notable quantitative and qualitative differences between the different Petitgrain samples according to the harvest time. Linalool (43.2% to 65.97%), linalyl acetate (0.77% to 24.77%), and α-terpineol (9.29% to 12.12%) were the main components. The most important number of components was registered for summer EOs (July and September). The 5 EOs submitted biological activities screening, namely, antioxidant and antimicrobial activities. Weak antioxidant activities (IC50 values >10000 mg/L) were registered by both 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonate assays, mostly because the weak amount of phenols in EOs. Antibacterial activities (12 microorganisms) were registered against Gram-positive bacteria [Bacillus subtilis (MIC = 2.7 mg/mL), Staphylococcus aureus (4.8 mg/mL)], and moderated ones against yeasts [Saccharomyces cerevisiae (9.2 mg/mL)] and fungi [Mucor ramannianus (5 mg/mL)]. Positive correlations between the identified compounds and the antimicrobial activities were noted. Many compounds were correlated to antimicrobial activity mainly caryophyllene oxide against Escherichia coli (R2= 0.99), S. cerevisiae (R2= 0.99), and Fusarium culmorum (R2= 0.99). © 2012 Institute of Food Technologists®.

Ellouze I.,Institute Preparatoire aux Etudes Scientifiques et Techniques | Abderrabba M.,Institute Preparatoire aux Etudes Scientifiques et Techniques
Journal of Materials and Environmental Science | Year: 2014

In order to assess the kinetics of extraction Citrus aurantium leaves underwent hydrodistillation with a Clevenger apparatus. Essential oil was collected every 15 minutes during the whole extraction period. Yield variation during extraction period revealed an exponential aspect curve with 95% of maximum yield at 150 minutes. Sixty one compounds were identified during extraction time. Chromatographic analysis showed notable differences between the different petitgrain samples especially for the major components: linalool (29.74-62.43%), α-terpineol (3.04-15.69%) and linalyl acetate (5.64-25.38%). Important variations were observed in petitgrain chemical composition according to extraction time and each component presented a specific kinetic according to extraction time. These variations may be the expression of variable chemical and physical phenomena that take place in Clevenger hydrodistillation batch.

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