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Partager le résultat de cette recherche Interroger des sources externesLes formations évaporitiques triasiques des hautes plaines Sétifiennes (NE Algérien) / Aboutaleb Mezerzi
Titre : Les formations évaporitiques triasiques des hautes plaines Sétifiennes (NE Algérien) : Répartition et caractrisation des substances minirales associées Type de document : texte imprimé Auteurs : Aboutaleb Mezerzi, Auteur ; Abdeslam Demdoum, Directeur de thèse ; Ramdane Marmi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 178 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Sciences de la terreTags : Hautes plaines sétifiènnes koudiat El Bassour diapir sel gemme gypse cuivre fer Draa El Djebbas exploitation répartition guelle triasique caractérisation évaporites Setifian high plains triassic rock salt gypsum copper iron guellal characterization evaporites السهول العليا السطايفية المتبخرات ديابير الجبس النحاس الاستغلال الحديد قلال الملح الصخري خصائص كدية الباصور ذراع الجباس Index. décimale : 550 Sciences de la terre Résumé : tract The main purpose of this work was the characterization of minerals associated with evaporite Triassic formations of the Setifian High Plains.
In the north eastern of Algeria and between the two barriers of mountains, Hodna in
South and Babors in North, situated a vast plains, commonly known as the Setifian High
Plains. This zone occupies the central part of the wilaya of Setif, and it's a part of the externe areas of the Alps, eastern Algeria, between the Tellian slicks in the North and the forward land autochton in the South. It is considered a closed continental basin, filled by Neogene and Quaternary deposits.
The genesis of evaporite deposits caused by the lagoon system that prevailed in the Triassic era with an arid climate and a high degree of evaporation which led to the precipitation of ions, Ca ++ So3--, Na +, Cl-, giving salt deposits and gypsum.
The spatial distribution, and the surface movement of the Triassic evaporite formations in the Setifian High Plains would probably caused by the phenomenon of overlapping slicks of alloctons to the south. We find five (5) evaporite formations dating from the Triassic; Guellal, Koudiat el Bassour, Methgoub Ras, Draa El Djebbas and Jebel el Garsa.
The principal minerals related to Triassic outcrops are represented essentially by evaporite deposits (gypsum and rock salt) .The particularity is marked by the presence of metallic minerals (iron and copper) in the blocks associated with evaporites Koudiat El Bassour.
The iron mineralization associated with copper, is hosted mainly in carbonate rocks, considered by the ancient writers as an infraliasiques formation. The morphology of the mineralized bodies is characterized essentially by a vein shape and stockworks type.
The mineralogical characterization by XRD and metallographic microscopic observation shows that the mineralization is usually oxidized brown-black (hematite, goethite, limonite) developed on iron carbonate (siderite, ankerite) associated with a few sulphides (chalcopyrite covellite, pyrite) and copper carbonate (malachite).
Gypsum deposits are widespread in all the Triassic outcrops of the region; it comes in four (4) forms (fibrous, crystalline, microcrystalline and grainy). The Gîtologics characters, the mineralogical characterization by XRD and chemical analysis by fluorescence X show that the gypsum is characterized by a variation of quality and quantity in an outcrops to another. As such, the economic importance gypsum deposit is observed in the Triassic of Guellal.
Contrary to gypsum, rock salt (halite) is prevalent only in the depth of the Triassic
outcrop in Guellal, and is forming a deposit of a great economic importance.
Geological, gîtologic and chemical characteristics of the rock salt deposits are the source of economic interest. Geophysical, mining and hydrogeological works of research in the diapir, which resulted an exploitation of salts for human consumption and industrial purposes.
The exploitation is more methodical, it is provided by the ENASel.Diplôme : Magistère En ligne : ../theses/sc-terre/MEZ6885.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10208 Les formations évaporitiques triasiques des hautes plaines Sétifiennes (NE Algérien) : Répartition et caractrisation des substances minirales associées [texte imprimé] / Aboutaleb Mezerzi, Auteur ; Abdeslam Demdoum, Directeur de thèse ; Ramdane Marmi, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2015 . - 178 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Sciences de la terreTags : Hautes plaines sétifiènnes koudiat El Bassour diapir sel gemme gypse cuivre fer Draa El Djebbas exploitation répartition guelle triasique caractérisation évaporites Setifian high plains triassic rock salt gypsum copper iron guellal characterization evaporites السهول العليا السطايفية المتبخرات ديابير الجبس النحاس الاستغلال الحديد قلال الملح الصخري خصائص كدية الباصور ذراع الجباس Index. décimale : 550 Sciences de la terre Résumé : tract The main purpose of this work was the characterization of minerals associated with evaporite Triassic formations of the Setifian High Plains.
In the north eastern of Algeria and between the two barriers of mountains, Hodna in
South and Babors in North, situated a vast plains, commonly known as the Setifian High
Plains. This zone occupies the central part of the wilaya of Setif, and it's a part of the externe areas of the Alps, eastern Algeria, between the Tellian slicks in the North and the forward land autochton in the South. It is considered a closed continental basin, filled by Neogene and Quaternary deposits.
The genesis of evaporite deposits caused by the lagoon system that prevailed in the Triassic era with an arid climate and a high degree of evaporation which led to the precipitation of ions, Ca ++ So3--, Na +, Cl-, giving salt deposits and gypsum.
The spatial distribution, and the surface movement of the Triassic evaporite formations in the Setifian High Plains would probably caused by the phenomenon of overlapping slicks of alloctons to the south. We find five (5) evaporite formations dating from the Triassic; Guellal, Koudiat el Bassour, Methgoub Ras, Draa El Djebbas and Jebel el Garsa.
The principal minerals related to Triassic outcrops are represented essentially by evaporite deposits (gypsum and rock salt) .The particularity is marked by the presence of metallic minerals (iron and copper) in the blocks associated with evaporites Koudiat El Bassour.
The iron mineralization associated with copper, is hosted mainly in carbonate rocks, considered by the ancient writers as an infraliasiques formation. The morphology of the mineralized bodies is characterized essentially by a vein shape and stockworks type.
The mineralogical characterization by XRD and metallographic microscopic observation shows that the mineralization is usually oxidized brown-black (hematite, goethite, limonite) developed on iron carbonate (siderite, ankerite) associated with a few sulphides (chalcopyrite covellite, pyrite) and copper carbonate (malachite).
Gypsum deposits are widespread in all the Triassic outcrops of the region; it comes in four (4) forms (fibrous, crystalline, microcrystalline and grainy). The Gîtologics characters, the mineralogical characterization by XRD and chemical analysis by fluorescence X show that the gypsum is characterized by a variation of quality and quantity in an outcrops to another. As such, the economic importance gypsum deposit is observed in the Triassic of Guellal.
Contrary to gypsum, rock salt (halite) is prevalent only in the depth of the Triassic
outcrop in Guellal, and is forming a deposit of a great economic importance.
Geological, gîtologic and chemical characteristics of the rock salt deposits are the source of economic interest. Geophysical, mining and hydrogeological works of research in the diapir, which resulted an exploitation of salts for human consumption and industrial purposes.
The exploitation is more methodical, it is provided by the ENASel.Diplôme : Magistère En ligne : ../theses/sc-terre/MEZ6885.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10208 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MEZ/6885 MEZ/6885 Thèse Bibliothèque principale Thèses Disponible
Titre : Caractérisation de l'huile d'olive algérienne : apport des méthodes chimiothérapiques. Type de document : texte imprimé Auteurs : Hamida Benabid, Auteur ; Hacène Namoune, Directeur de thèse ; Douglas N. Rutledge, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2009 Importance : 165 f. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Sciences Alimentaires Caractérisation Fluorescence Huile d'olive Régions Chimiométrie Olive oil Characterization Areas Chemometrics زيت الزيتون المناطق مصفوفات مضان كيميومتري Index. décimale : 640 Industrie Alimentaire Résumé : Olive oil is one of the oldest vegetable oils and the only one that can be consumed in its raw form without prior treatment. The well-known health benefits of olive oil are linked to its fatty acid composition in which oleic acid is the main component, and the presence of minor biomolecules, such as vitamins and natural antioxidants.
The strong demand for quality virgin olive oil is not only due to its health virtues, but also to its organoleptic properties.
In Algeria, plantations are characterized by great diversity and for the most part, by a traditional olive orchard. The consumption of oil maâsras is today a basic diet in many rural areas of the country. In these regions, oils are considered to be of good quality. The present study on olive oil produced in several olive growing regions of Algeria has the dual purpose of studying the chemical parameters and fatty acid composition by conventional analytical methods, and of characterizing these oils by spectral methods, including 3D- fluorescence spectroscopy.
Different chemometric methods: Principal Component Analysis (PCA), Canonical Discriminant Analysis (CDA), Independent Component Analysis (ICA), and PARAFAC (PARAllel FACtor analysis) are used to treat the data.
The first results indicate that the chemical composition of olive oils from different regions of Algeria is quite variable.
The Principal Component Analysis (PCA) was used for an initial exploratory analysis of the data. The first three latent variables explain 64.1% of the total variance of the samples from the five regions. Then, a Canonical Discriminant Analysis (CDA) showed that the most discriminant variables are K270 and Delta K for oil samples from the region of Constantine, the peroxide and γ-tocopherol for samples from the regions of Tizi Ouzou and Sétif, respectively.
The variations due to the presence of Rayleigh and Raman scattering in excitation– emission fluorescence matrices, distort the PARAFAC model.
A solution to eliminate the artefacts interfering with the relevant information was achieved by applying Independent Component Analysis to the row-wise unfolded array. A PARAFAC model was then built on the refolded array, reconstructed without the independent component(s) related to the “artefact signals”. The PARAFAC components obtained were interpreted by relating them to some compounds present in the analysed samples. The results of multivariate analyses show that the chemical parameters of olive oils contain enough information to distinguish the production areas of studied Algerian oil.Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/BEN5330.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=4438 Caractérisation de l'huile d'olive algérienne : apport des méthodes chimiothérapiques. [texte imprimé] / Hamida Benabid, Auteur ; Hacène Namoune, Directeur de thèse ; Douglas N. Rutledge, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2009 . - 165 f.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Sciences Alimentaires Caractérisation Fluorescence Huile d'olive Régions Chimiométrie Olive oil Characterization Areas Chemometrics زيت الزيتون المناطق مصفوفات مضان كيميومتري Index. décimale : 640 Industrie Alimentaire Résumé : Olive oil is one of the oldest vegetable oils and the only one that can be consumed in its raw form without prior treatment. The well-known health benefits of olive oil are linked to its fatty acid composition in which oleic acid is the main component, and the presence of minor biomolecules, such as vitamins and natural antioxidants.
The strong demand for quality virgin olive oil is not only due to its health virtues, but also to its organoleptic properties.
In Algeria, plantations are characterized by great diversity and for the most part, by a traditional olive orchard. The consumption of oil maâsras is today a basic diet in many rural areas of the country. In these regions, oils are considered to be of good quality. The present study on olive oil produced in several olive growing regions of Algeria has the dual purpose of studying the chemical parameters and fatty acid composition by conventional analytical methods, and of characterizing these oils by spectral methods, including 3D- fluorescence spectroscopy.
Different chemometric methods: Principal Component Analysis (PCA), Canonical Discriminant Analysis (CDA), Independent Component Analysis (ICA), and PARAFAC (PARAllel FACtor analysis) are used to treat the data.
The first results indicate that the chemical composition of olive oils from different regions of Algeria is quite variable.
The Principal Component Analysis (PCA) was used for an initial exploratory analysis of the data. The first three latent variables explain 64.1% of the total variance of the samples from the five regions. Then, a Canonical Discriminant Analysis (CDA) showed that the most discriminant variables are K270 and Delta K for oil samples from the region of Constantine, the peroxide and γ-tocopherol for samples from the regions of Tizi Ouzou and Sétif, respectively.
The variations due to the presence of Rayleigh and Raman scattering in excitation– emission fluorescence matrices, distort the PARAFAC model.
A solution to eliminate the artefacts interfering with the relevant information was achieved by applying Independent Component Analysis to the row-wise unfolded array. A PARAFAC model was then built on the refolded array, reconstructed without the independent component(s) related to the “artefact signals”. The PARAFAC components obtained were interpreted by relating them to some compounds present in the analysed samples. The results of multivariate analyses show that the chemical parameters of olive oils contain enough information to distinguish the production areas of studied Algerian oil.Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/BEN5330.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=4438 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/5330 BEN/5330 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de dispositifs de CND-CF (Contrôle non destructif par Courants de Foucault) appliqués à la caractérisation de matériaux composites à fibres de carbone Type de document : texte imprimé Auteurs : Abderraouf Bouloudenine, Auteur ; Mohamed El Hadi Latreche, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 108 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Electro-techniqueTags : Contrôle non destructif par courants de Foucault caractérisation matériaux composites à fibre de carbone éléments finis 3D anisotropie ondulation des fibres Eddy currents non-destructive testing characterization carbon fiber reinforced polymer 3D finite element anisotropy fiber waviness إختبار غير مدمر بالتيارات الدوامة توصيف المواد المركبة المقواة بالألياف الكربونية العناصر المنتهية تباين تموج الألياف Index. décimale : 622 Electro-Technique Résumé : Non Destructive Testing plays an essential role in safety, quality and the reliability of industrial systems. In this thesis, two eddy current sensors designed form several coils that are placed in array form to characterize fiber orientation and for detecting in-plane fiber waviness in unidirectional CFRP.
The principles of the proposed sensors are based on those of conventional rotating sensors. Our proposals allow the elimination of mechanical rotation, which offers advantages of speed of inspection, precision and miniaturization. The first sensor is based on the absolute mode; however the second uses the transmission-reception mode. To benefit at the same time from the advantages of the interactive arrayed sensor and the receiving arrayed sensor, we have proposed a synthesis of these two sensors in a single device. This gives a possibility to use a single sensor that functions both as an interactive arrayed sensor and as a receiving arrayed sensor. We are used the 3D finite elements method in 'Comsol multiphysics' environment to study the electromagnetic phenomena. To validate the
results obtained by simulation, experimental measurements were carried-out in the case of two coils sensor.
Diplôme : Doctorat En ligne : ../theses/electrotec/BOU7289.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10904 Etude de dispositifs de CND-CF (Contrôle non destructif par Courants de Foucault) appliqués à la caractérisation de matériaux composites à fibres de carbone [texte imprimé] / Abderraouf Bouloudenine, Auteur ; Mohamed El Hadi Latreche, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 108 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Electro-techniqueTags : Contrôle non destructif par courants de Foucault caractérisation matériaux composites à fibre de carbone éléments finis 3D anisotropie ondulation des fibres Eddy currents non-destructive testing characterization carbon fiber reinforced polymer 3D finite element anisotropy fiber waviness إختبار غير مدمر بالتيارات الدوامة توصيف المواد المركبة المقواة بالألياف الكربونية العناصر المنتهية تباين تموج الألياف Index. décimale : 622 Electro-Technique Résumé : Non Destructive Testing plays an essential role in safety, quality and the reliability of industrial systems. In this thesis, two eddy current sensors designed form several coils that are placed in array form to characterize fiber orientation and for detecting in-plane fiber waviness in unidirectional CFRP.
The principles of the proposed sensors are based on those of conventional rotating sensors. Our proposals allow the elimination of mechanical rotation, which offers advantages of speed of inspection, precision and miniaturization. The first sensor is based on the absolute mode; however the second uses the transmission-reception mode. To benefit at the same time from the advantages of the interactive arrayed sensor and the receiving arrayed sensor, we have proposed a synthesis of these two sensors in a single device. This gives a possibility to use a single sensor that functions both as an interactive arrayed sensor and as a receiving arrayed sensor. We are used the 3D finite elements method in 'Comsol multiphysics' environment to study the electromagnetic phenomena. To validate the
results obtained by simulation, experimental measurements were carried-out in the case of two coils sensor.
Diplôme : Doctorat En ligne : ../theses/electrotec/BOU7289.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10904 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7289 BOU/7289 Thèse Bibliothèque principale Thèses Disponible
Titre : Purification et caractérisation d’un antigène somatique et d’une protéase à cystéine excrétée-sécrétée de Fasciola hepatica à intérêt immunodiagnostic. Type de document : texte imprimé Auteurs : Ahmed Hemici, Auteur ; Dalila Bendjeddou, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 206 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Biologie Animale: Immunologie Fasciola hepatica antigènes somatiques antigènes excrétés-sécrétés protéase typecystéine purification caractérisation ELISA Western blot somatic antigens excreted-secreted antigens cystéine like- protease characterization المستضدات الجسدية المستضدات الافرازية بروتيياز السستيين تنقية توصيف Index. décimale : 570 Sciences de la vie. Biologie Résumé :
The present study describes in its first experimental part, the isolation of an antigenic molecule from the total homogenate of Fasciola hepatica adult flukes, then purified to homogeneity using gel filtration chromatography followed by a specific affinity chromatography. Among the five antigenic fractions obtained by fractionation of the crude somatic extract on Sephadex G-200 gel, only the first fraction (F.1) gave a highly significant recipitation reaction with the Concanavalin A lectin. It was then purified to homogeneity through a ConA-Sepharose 4B affinity column and characterized by SDS-PAGE electrophoresis as a single-band with apparent MW of about 40 kDa. This pure molecule, whose immunoreactivity was very positive in the presence of rabbit specific antiserum, is therefore endowed with a significant antigenic activity. In addition, the immunodiagnostic reliability of this molecule was verified by Elisa; the assay using the purified fraction as antigen (ELISAPf) proved more sensitive than the Elisa using the excreted-secreted product (ELISAESP) (92.3% of sensitivity for Elisa(Pf) against 72% for Elisa(ESP)). However, the ELISA specificity using the purified fraction was slightly lower compared to that corresponding to excreted-secreted product (93.3% of specificity for ELISA(Pf) against 95.5% for ELISA(ESP)). In the second practical part, a proteolytic activity cysteine-like produced in the supernatant of adult fluke culture medium was purified and characterized by combination of acetone precipitation and two chromatographic methods. Through this three-step purification, the enzyme was purified 11-fold with a specific activity of 1893.9 U/mg and 31.5% recovery. Ultrafiltration was required to increase the purification fold to 13.1 with an overall specific activity of 2268.8 U/mg. The MW of the purified protease was estimated by SDSŔPAGE to be 22 kDa, while the proteolytic activity detection was carried out by zymography on non-denaturing SDSŔPAGE containing the casein as substrate. The enzyme has relative stability over a wide range of pH and temperature with optimal activity at pH 5.5 and 40 °C. Its activity was completely inhibited by specific inhibitors of cysteine proteases, namely 5 mM E-64 and 10 mM iodoacetamide. The practical interest of this purified molecule as an antigen was evaluated by Western blot using sera from sheep experimentally infected with metacercariae of F. hepatica. The pool of sera recognized a single band corresponding to this protease just after the 2nd week of infestation. The early detection of specific antibodies in the sera of infested animals suggests the application of this molecule to the immunological screening of fasciolosis by this technique.
Note de contenu :
Annexes.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/HEM7449.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11235 Purification et caractérisation d’un antigène somatique et d’une protéase à cystéine excrétée-sécrétée de Fasciola hepatica à intérêt immunodiagnostic. [texte imprimé] / Ahmed Hemici, Auteur ; Dalila Bendjeddou, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 206 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Biologie Animale: Immunologie Fasciola hepatica antigènes somatiques antigènes excrétés-sécrétés protéase typecystéine purification caractérisation ELISA Western blot somatic antigens excreted-secreted antigens cystéine like- protease characterization المستضدات الجسدية المستضدات الافرازية بروتيياز السستيين تنقية توصيف Index. décimale : 570 Sciences de la vie. Biologie Résumé :
The present study describes in its first experimental part, the isolation of an antigenic molecule from the total homogenate of Fasciola hepatica adult flukes, then purified to homogeneity using gel filtration chromatography followed by a specific affinity chromatography. Among the five antigenic fractions obtained by fractionation of the crude somatic extract on Sephadex G-200 gel, only the first fraction (F.1) gave a highly significant recipitation reaction with the Concanavalin A lectin. It was then purified to homogeneity through a ConA-Sepharose 4B affinity column and characterized by SDS-PAGE electrophoresis as a single-band with apparent MW of about 40 kDa. This pure molecule, whose immunoreactivity was very positive in the presence of rabbit specific antiserum, is therefore endowed with a significant antigenic activity. In addition, the immunodiagnostic reliability of this molecule was verified by Elisa; the assay using the purified fraction as antigen (ELISAPf) proved more sensitive than the Elisa using the excreted-secreted product (ELISAESP) (92.3% of sensitivity for Elisa(Pf) against 72% for Elisa(ESP)). However, the ELISA specificity using the purified fraction was slightly lower compared to that corresponding to excreted-secreted product (93.3% of specificity for ELISA(Pf) against 95.5% for ELISA(ESP)). In the second practical part, a proteolytic activity cysteine-like produced in the supernatant of adult fluke culture medium was purified and characterized by combination of acetone precipitation and two chromatographic methods. Through this three-step purification, the enzyme was purified 11-fold with a specific activity of 1893.9 U/mg and 31.5% recovery. Ultrafiltration was required to increase the purification fold to 13.1 with an overall specific activity of 2268.8 U/mg. The MW of the purified protease was estimated by SDSŔPAGE to be 22 kDa, while the proteolytic activity detection was carried out by zymography on non-denaturing SDSŔPAGE containing the casein as substrate. The enzyme has relative stability over a wide range of pH and temperature with optimal activity at pH 5.5 and 40 °C. Its activity was completely inhibited by specific inhibitors of cysteine proteases, namely 5 mM E-64 and 10 mM iodoacetamide. The practical interest of this purified molecule as an antigen was evaluated by Western blot using sera from sheep experimentally infected with metacercariae of F. hepatica. The pool of sera recognized a single band corresponding to this protease just after the 2nd week of infestation. The early detection of specific antibodies in the sera of infested animals suggests the application of this molecule to the immunological screening of fasciolosis by this technique.
Note de contenu :
Annexes.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/HEM7449.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11235 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité HEM/7449 HEM/7449 Thèse Bibliothèque principale Thèses Disponible
Titre : Purification, caractérisation et essais d’inhibition de la polyphénol-oxydase de l’abricot par des combinaisons : préparations de protéases végétales- acide ascorbique. Type de document : texte imprimé Auteurs : Ala eddine Derardja, Auteur ; Malika Barkat, Directeur de thèse ; Annette Rompel, Directeur de thèse Mention d'édition : 28/06/2020 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 150 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : technologie Alimentaire: Sciences Alimentaires Brunissement enzymatique abricot polyphénol oxydase purification caractérisation inhibition protéases végétales acide ascorbique Enzymatic browning apricot polyphenol oxidase characterization plant proteases ascorbic acid إسمرار إنزيمي مشمش بوليفينول أكسيداز تصفية توصيف تثبيط بروتيازات نباتية حمص الاسكوربيك Index. décimale : 640 Industrie Alimentaire Résumé :
Enzymatic browning generally is an undesirable phenomenon in the food industry. It is considered to be one of the biggest problems during apricot handling, storage, preservation and transformation. Browning reactions in fruits and vegetables are mainly initiated by polyphenol oxidase (PPO). Therefore, the objective of this thesis is extract, purify, characterize and then inhibit apricot PPO (PaPPO). Thus, herein describes a new method to inhibit as well as inactivate PaPPO by combinations of plant proteases (papain, calotropain, ficin and bromelain) and ascorbic acid. Our results show that PaPPO is present in the fruit in its latent form (L-PaPPO). The purified PaPPO was characterized with a molecular weight of 63 kDa on SDS-PAGE, a pH and a temperature optimum at pH and 45 °C for catechol as substrate. The activity was enhanced by low concentrations (≤ 2 mM) of SDS. It showed diphenolase activity and highest affinity toward 4-methylcatechol (Km = 2.0 mM) and chlorogenic acid (Km = 2.7 mM). L-PaPPO was found to be spontaneously activated during storage at 4 °C, creating a new band at 38 kDa representing the activated form (A-PaPPO). Surprisingly the active form showed a weak monophenolase activity. The mass of A-PaPPO was determined by mass spectrometry as 37 455.6 Da (Asp102 → Leu429). Both L-PaPPO and A-PaPPO were identified as PPO corresponding to the known PaPPO sequence (UniProt O81103) by means of peptide mass fingerprinting. The inactivation of PaPPO with proteases showed that the selected proteases were able to inactivate PaPPO at pH 4.5, with the degree of inactivation proportional to incubation time and protease concentration. Papain was the most effective protease, with 50 μg completely inactivating PaPPO in less than one hour. AA prevented
browning reactions that occur before or during PaPPO inactivation by protease. The combinations of ascorbic acid/proteases (AA/P) were highly effective in vitro, where 2 mM AA/500 μg P inhibited PaPPO activity completely over 24 h. The combination of AA/P was also effective in vivo, as treated apricot purees preserved their color (p < 0.0001, compared to untreated samples after 10 days of storage). The results demonstrate that AA/P combinations constitute a promising practical anti-browning method with feasible application in the food industry that can help control enzymatic browning in fruits and vegetables.
Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/DER7652.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11486 Purification, caractérisation et essais d’inhibition de la polyphénol-oxydase de l’abricot par des combinaisons : préparations de protéases végétales- acide ascorbique. [texte imprimé] / Ala eddine Derardja, Auteur ; Malika Barkat, Directeur de thèse ; Annette Rompel, Directeur de thèse . - 28/06/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 150 f. ; 30 cm.
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Nutrition, Alimentation et Technologies Agro-AlimentairesTags : technologie Alimentaire: Sciences Alimentaires Brunissement enzymatique abricot polyphénol oxydase purification caractérisation inhibition protéases végétales acide ascorbique Enzymatic browning apricot polyphenol oxidase characterization plant proteases ascorbic acid إسمرار إنزيمي مشمش بوليفينول أكسيداز تصفية توصيف تثبيط بروتيازات نباتية حمص الاسكوربيك Index. décimale : 640 Industrie Alimentaire Résumé :
Enzymatic browning generally is an undesirable phenomenon in the food industry. It is considered to be one of the biggest problems during apricot handling, storage, preservation and transformation. Browning reactions in fruits and vegetables are mainly initiated by polyphenol oxidase (PPO). Therefore, the objective of this thesis is extract, purify, characterize and then inhibit apricot PPO (PaPPO). Thus, herein describes a new method to inhibit as well as inactivate PaPPO by combinations of plant proteases (papain, calotropain, ficin and bromelain) and ascorbic acid. Our results show that PaPPO is present in the fruit in its latent form (L-PaPPO). The purified PaPPO was characterized with a molecular weight of 63 kDa on SDS-PAGE, a pH and a temperature optimum at pH and 45 °C for catechol as substrate. The activity was enhanced by low concentrations (≤ 2 mM) of SDS. It showed diphenolase activity and highest affinity toward 4-methylcatechol (Km = 2.0 mM) and chlorogenic acid (Km = 2.7 mM). L-PaPPO was found to be spontaneously activated during storage at 4 °C, creating a new band at 38 kDa representing the activated form (A-PaPPO). Surprisingly the active form showed a weak monophenolase activity. The mass of A-PaPPO was determined by mass spectrometry as 37 455.6 Da (Asp102 → Leu429). Both L-PaPPO and A-PaPPO were identified as PPO corresponding to the known PaPPO sequence (UniProt O81103) by means of peptide mass fingerprinting. The inactivation of PaPPO with proteases showed that the selected proteases were able to inactivate PaPPO at pH 4.5, with the degree of inactivation proportional to incubation time and protease concentration. Papain was the most effective protease, with 50 μg completely inactivating PaPPO in less than one hour. AA prevented
browning reactions that occur before or during PaPPO inactivation by protease. The combinations of ascorbic acid/proteases (AA/P) were highly effective in vitro, where 2 mM AA/500 μg P inhibited PaPPO activity completely over 24 h. The combination of AA/P was also effective in vivo, as treated apricot purees preserved their color (p < 0.0001, compared to untreated samples after 10 days of storage). The results demonstrate that AA/P combinations constitute a promising practical anti-browning method with feasible application in the food industry that can help control enzymatic browning in fruits and vegetables.
Note de contenu :
Annexes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/DER7652.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11486 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité DER/7652 DER/7652 Thèse Bibliothèque principale Thèses Disponible
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