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Partager le résultat de cette recherche Interroger des sources externesCaractérisation microbiologique et de la protéolyse du fromage traditionnel Algérien'Bouhezza' de ferme / Zineddine Saoudi
Titre : Caractérisation microbiologique et de la protéolyse du fromage traditionnel Algérien'Bouhezza' de ferme Type de document : texte imprimé Auteurs : Zineddine Saoudi, Auteur ; Mohamed-Nasreddine Zidoune, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2012 Importance : 94 f. Format : 31 cm. Note générale : Magister
2 copies imprimées disponiblesLangues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Fromage traditionnel Bouhezze affinage microbiologie protéolyse PCR-TTGE RP-HPLC PAGE-Urée Index. décimale : 640 Industrie Alimentaire Diplôme : Magistère En ligne : ../theses/agronomie/SAO6147.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6044 Caractérisation microbiologique et de la protéolyse du fromage traditionnel Algérien'Bouhezza' de ferme [texte imprimé] / Zineddine Saoudi, Auteur ; Mohamed-Nasreddine Zidoune, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2012 . - 94 f. ; 31 cm.
Magister
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Fromage traditionnel Bouhezze affinage microbiologie protéolyse PCR-TTGE RP-HPLC PAGE-Urée Index. décimale : 640 Industrie Alimentaire Diplôme : Magistère En ligne : ../theses/agronomie/SAO6147.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6044 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SAO/6147 SAO/6147 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l’étude pour la caractérisation du fromage traditionnel « Bouhezza » au lait de chèvre. Type de document : texte imprimé Auteurs : Hacene Medjoudj, Auteur ; Mohammed Nasreddine Zidoune, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 225 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Chaouia Chekoua (Djeld) lait cru de chèvre Fromage traditionnel Bouhezza physico-chimie et
microbiologie Qualité Hygiénique classification bactéries lactiques affinage protéolyse lipolyse profil aromatique profil de texture raw goat's milk traditional Bouhezza cheese physico-chemistry and
microbiology hygienic quality lactic acid bacteria ripening proteolysis lipolysis aromatic profile texture profile "الشاوية الشكوة أوجلد بوهزة حليب الماعز الخام جبن بوهزة التقليدي الكيميا الفيزيائية وعلم الأحيا الدقيقة و الجودة الحية والتني وبكتيريا حمض ال كتيك والتكرير والملمس الشخ ي"Index. décimale : 640 Industrie Alimentaire Résumé : Bouhezza is a traditional Algerian cheese, from Chaouia terroir produced from different types of milk (goat, sheep and cow). Its manufacture refining is carried out in a skin bag prepared traditionally from goatskin or sheepskin, called Djeld or Chekoua of Bouhezza.
The objective of the study was to contribute to the characterization of traditional cheese Bouhezza through a survey in different regions of Chaouia, in northeastern Algeria. A physicochemical, biochemical and microbiological characterization of Bouhezza prepared with goat’ raw milk.
The survey was conducted among 617 families in urban areas and 225 in rural areas, in order to establish the production diagram of Bouhezza and delineate the geographical area of his practice. Thirteen cheese making of Bouhezza with raw goat milk were made; 2 experimental in laboratory (LNTA-I.N.A.T.A-A) - University of Constantine 1) and 11 in farms (4 in Tébessa and 7 in Oum El-Bouaghi). During ripening, physicochemical and microbiological analyzes were carried out. Determination of proteolysis during maturation, isolation and identification of proteolytic lactic acid bacteria found in the cheese were performed by SDS-PAGE electrophoresis and PCR. Peptide profile was analyzed by RP-HPLC. The evaluation of the proteolysis rate, highlighting profiles lipid by GC, and aromatic by GC-MS, with a sensory analysis and texture profile of Bouhezza cheese. The microbiological characterization of cheese with identification of lactic acid bacteria by sequencing of 16S rDNA
using PCR-TTGE.
The investigation confirmed the practice of Bouhezza in different regions of Chaouia in 5 wilayas; Khenchela, Batna, Tebessa, Souk Ahras and Oum El Bouaghi. Of 498 respondents, 49.76% (247) know and manufacture Bouhezza. He is also called ""Milh Dhouaba"" at Tébessa.
The microbiological analysis revealed a high number of lactic acid bacteria, of the order of 7.7 to 8.9 log cfu / g of cheese, the absence of pathogenic bacteria, while the flora of contamination was present at the beginning of manufacturing, but decreased with time. Therefore, the cheese has an acceptable hygienic quality. The lactic flora showed fluctuations during manufacture with a heavy load of lactic Streptococci consisting essentially of strains of:
Lc. lactis subsp. cremoris and S. gallolyticus subsp. macedonicus. Lactobacilli are present with a low charge, composed of Lb. plantarum, Lb. johnsonni, Lb. gasseri; Lb. fermentum, Lb. helveticus, Lb. acidophilus and Lb. crispatus.
Bouhezza is an acidic fermented product with an average pH of 3.88 and an average acidity of 1.85 g / 100 g of lactic acid. The protein / DM level was 22.20% and the fat / DM content 41.18%. The results showed that the dry matter averaged 35.65%. The moisture content in the defatted cheese is 68.55% and 79.05%, the fat-in-dry matter of 47.65% and 34.77%.
Nitrogen fractions soluble in water and in 12% TCA decreased at the beginning of the ripening process and then increased at the end of ripening. SDS-PAGE analysis on Bouhezza samples showed moderate proteolysis, from 30 days of maturation. Urea PAGE of caseins showed rapid proteolysis. Six proteolytic lactic acid bacteria (LABs), four of which have been identified by 16S rDNA sequencing, were two strains of Enterococcus faecalis, one Enterococcus faecium and one Lactobacillus paracasei ssp. paracasei.
RP-HPLC analysis of the soluble fraction at pH 4.4 showed the changes that occurred during the refining process where the peptide profile confirmed proteolysis during cheese maturation.
A total of more than 100 volatile compounds have been identified in goat cheese Bouhezza, the main classes of which are carboxylic acids, esters and alcohols, followed by aldehydes, ketones, terpenes and various compounds.
Goat's milk cheese has been classified as ripened cheeses semi-soft to soft and semi-fat to all fat according to the codex alimentarius. Bouhezza has a good microbial diversity, which would contribute to its ripening and provide it with its organoleptic characteristics. The sensory evaluation showed that Bouhezza is salty, spicy and intense in smell and aroma. The study showed that Bouhezza cheese was rich in volatiles with a variety of odorous components that give the cheese its particularities reflecting the identity of this local cheese.
Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/MED7235.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10820 Contribution à l’étude pour la caractérisation du fromage traditionnel « Bouhezza » au lait de chèvre. [texte imprimé] / Hacene Medjoudj, Auteur ; Mohammed Nasreddine Zidoune, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 225 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Chaouia Chekoua (Djeld) lait cru de chèvre Fromage traditionnel Bouhezza physico-chimie et
microbiologie Qualité Hygiénique classification bactéries lactiques affinage protéolyse lipolyse profil aromatique profil de texture raw goat's milk traditional Bouhezza cheese physico-chemistry and
microbiology hygienic quality lactic acid bacteria ripening proteolysis lipolysis aromatic profile texture profile "الشاوية الشكوة أوجلد بوهزة حليب الماعز الخام جبن بوهزة التقليدي الكيميا الفيزيائية وعلم الأحيا الدقيقة و الجودة الحية والتني وبكتيريا حمض ال كتيك والتكرير والملمس الشخ ي"Index. décimale : 640 Industrie Alimentaire Résumé : Bouhezza is a traditional Algerian cheese, from Chaouia terroir produced from different types of milk (goat, sheep and cow). Its manufacture refining is carried out in a skin bag prepared traditionally from goatskin or sheepskin, called Djeld or Chekoua of Bouhezza.
The objective of the study was to contribute to the characterization of traditional cheese Bouhezza through a survey in different regions of Chaouia, in northeastern Algeria. A physicochemical, biochemical and microbiological characterization of Bouhezza prepared with goat’ raw milk.
The survey was conducted among 617 families in urban areas and 225 in rural areas, in order to establish the production diagram of Bouhezza and delineate the geographical area of his practice. Thirteen cheese making of Bouhezza with raw goat milk were made; 2 experimental in laboratory (LNTA-I.N.A.T.A-A) - University of Constantine 1) and 11 in farms (4 in Tébessa and 7 in Oum El-Bouaghi). During ripening, physicochemical and microbiological analyzes were carried out. Determination of proteolysis during maturation, isolation and identification of proteolytic lactic acid bacteria found in the cheese were performed by SDS-PAGE electrophoresis and PCR. Peptide profile was analyzed by RP-HPLC. The evaluation of the proteolysis rate, highlighting profiles lipid by GC, and aromatic by GC-MS, with a sensory analysis and texture profile of Bouhezza cheese. The microbiological characterization of cheese with identification of lactic acid bacteria by sequencing of 16S rDNA
using PCR-TTGE.
The investigation confirmed the practice of Bouhezza in different regions of Chaouia in 5 wilayas; Khenchela, Batna, Tebessa, Souk Ahras and Oum El Bouaghi. Of 498 respondents, 49.76% (247) know and manufacture Bouhezza. He is also called ""Milh Dhouaba"" at Tébessa.
The microbiological analysis revealed a high number of lactic acid bacteria, of the order of 7.7 to 8.9 log cfu / g of cheese, the absence of pathogenic bacteria, while the flora of contamination was present at the beginning of manufacturing, but decreased with time. Therefore, the cheese has an acceptable hygienic quality. The lactic flora showed fluctuations during manufacture with a heavy load of lactic Streptococci consisting essentially of strains of:
Lc. lactis subsp. cremoris and S. gallolyticus subsp. macedonicus. Lactobacilli are present with a low charge, composed of Lb. plantarum, Lb. johnsonni, Lb. gasseri; Lb. fermentum, Lb. helveticus, Lb. acidophilus and Lb. crispatus.
Bouhezza is an acidic fermented product with an average pH of 3.88 and an average acidity of 1.85 g / 100 g of lactic acid. The protein / DM level was 22.20% and the fat / DM content 41.18%. The results showed that the dry matter averaged 35.65%. The moisture content in the defatted cheese is 68.55% and 79.05%, the fat-in-dry matter of 47.65% and 34.77%.
Nitrogen fractions soluble in water and in 12% TCA decreased at the beginning of the ripening process and then increased at the end of ripening. SDS-PAGE analysis on Bouhezza samples showed moderate proteolysis, from 30 days of maturation. Urea PAGE of caseins showed rapid proteolysis. Six proteolytic lactic acid bacteria (LABs), four of which have been identified by 16S rDNA sequencing, were two strains of Enterococcus faecalis, one Enterococcus faecium and one Lactobacillus paracasei ssp. paracasei.
RP-HPLC analysis of the soluble fraction at pH 4.4 showed the changes that occurred during the refining process where the peptide profile confirmed proteolysis during cheese maturation.
A total of more than 100 volatile compounds have been identified in goat cheese Bouhezza, the main classes of which are carboxylic acids, esters and alcohols, followed by aldehydes, ketones, terpenes and various compounds.
Goat's milk cheese has been classified as ripened cheeses semi-soft to soft and semi-fat to all fat according to the codex alimentarius. Bouhezza has a good microbial diversity, which would contribute to its ripening and provide it with its organoleptic characteristics. The sensory evaluation showed that Bouhezza is salty, spicy and intense in smell and aroma. The study showed that Bouhezza cheese was rich in volatiles with a variety of odorous components that give the cheese its particularities reflecting the identity of this local cheese.
Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/MED7235.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10820 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire 
Titre : Etude de parametres physico-chimiques et biochimiques en cinetique au cours de la maturation de la viande de dromadaire Type de document : texte imprimé Auteurs : Hanane Smili, Auteur ; Abdelghani Boudjellal, Directeur de thèse ; Abdelatif Adamou, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2014 Importance : 134 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : dromedary meat age tenderization pH drip loss proteolysis viande de dromadaire âge maturation exsudation protéolyse لحم الإبل العمر نضج الحموضة قدرة تخزین الماء تفكك البروتینات Index. décimale : 640 Industrie Alimentaire Résumé : The aim of this study is to contribute to the determination of the age at slaughter effect’s on dromedary (Camelus dromedarius) meat caractestic during tenderization by the studying physico-chemical, biochemical and technological parameters.
Twelve Sahraoui’s population dromedaries reared on extensive system and destined to commercialization are used. Three groups of age are investigated 1-4, 6-8 and 10-19 years. The Longissimus lumborum muscle excised within the first hour post-slaughter is used to characterize its contractile fiber type by the myosine heavy chains isoform separation on SDS PAGE. The evolution of pH and water holding capacity of myofibrillar proteins are characterized. The proteolysis of myofibrillar proteins during tenderization is estimated by SDS PAGE. And actin fragments are revealed by western blot analysis.
Finally, the drip loss of the muscle during conservation at 5°C, is estimated.
The carcass yield is the highest with 68% for 6-8 years dromedaries. The Longissimus lumborum muscle is characterized by the presence of MyHC IIa, with no effect of age at slaughter. However, significant effect of age on pH drop is noted. In average, it falls from 6.68 to 5.71; with highest value for 1-4 years dromedaries. The rate
and the extent of pH fall are greater with increased age. One or two stability steps are observed. Water holding capacity of myofibrillar proteins increased with tenderization, with highest value observed for the youngest animals.
Important post mortem proteolysis is seen after 10h post-slaughter for 6-8 years animals. The actin is degraded since 1h post mortem and the fragments revealed are of about 36, 33 and 31 kDa. Small fragments of about 14 kDa are generated earlier with increased age, contrary to the 26 kDa fragments.
Drip loss of the muscle during conservation at 5°C is on average 7% during the 72h post mortem. The percentage of exudation is greater for the group of 10-19 years. Drip loss of the muscle generates financial losses for 10 kg of muscle varying between 300 to 600 DA.Diplôme : Magistère En ligne : ../theses/agronomie/SMI6448.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9483 Etude de parametres physico-chimiques et biochimiques en cinetique au cours de la maturation de la viande de dromadaire [texte imprimé] / Hanane Smili, Auteur ; Abdelghani Boudjellal, Directeur de thèse ; Abdelatif Adamou, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2014 . - 134 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : dromedary meat age tenderization pH drip loss proteolysis viande de dromadaire âge maturation exsudation protéolyse لحم الإبل العمر نضج الحموضة قدرة تخزین الماء تفكك البروتینات Index. décimale : 640 Industrie Alimentaire Résumé : The aim of this study is to contribute to the determination of the age at slaughter effect’s on dromedary (Camelus dromedarius) meat caractestic during tenderization by the studying physico-chemical, biochemical and technological parameters.
Twelve Sahraoui’s population dromedaries reared on extensive system and destined to commercialization are used. Three groups of age are investigated 1-4, 6-8 and 10-19 years. The Longissimus lumborum muscle excised within the first hour post-slaughter is used to characterize its contractile fiber type by the myosine heavy chains isoform separation on SDS PAGE. The evolution of pH and water holding capacity of myofibrillar proteins are characterized. The proteolysis of myofibrillar proteins during tenderization is estimated by SDS PAGE. And actin fragments are revealed by western blot analysis.
Finally, the drip loss of the muscle during conservation at 5°C, is estimated.
The carcass yield is the highest with 68% for 6-8 years dromedaries. The Longissimus lumborum muscle is characterized by the presence of MyHC IIa, with no effect of age at slaughter. However, significant effect of age on pH drop is noted. In average, it falls from 6.68 to 5.71; with highest value for 1-4 years dromedaries. The rate
and the extent of pH fall are greater with increased age. One or two stability steps are observed. Water holding capacity of myofibrillar proteins increased with tenderization, with highest value observed for the youngest animals.
Important post mortem proteolysis is seen after 10h post-slaughter for 6-8 years animals. The actin is degraded since 1h post mortem and the fragments revealed are of about 36, 33 and 31 kDa. Small fragments of about 14 kDa are generated earlier with increased age, contrary to the 26 kDa fragments.
Drip loss of the muscle during conservation at 5°C is on average 7% during the 72h post mortem. The percentage of exudation is greater for the group of 10-19 years. Drip loss of the muscle generates financial losses for 10 kg of muscle varying between 300 to 600 DA.Diplôme : Magistère En ligne : ../theses/agronomie/SMI6448.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9483 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SMI/6448 SMI/6448 Thèse Bibliothèque principale Thèses Disponible Documents numériques
texte intégraleAdobe Acrobat PDF
Titre : Extraction de la pepsine et utilisation dans la coagulation du lait en vue d’une valorisation des proventricules de volailles au profit de la filière lait en Algérie Type de document : texte imprimé Auteurs : Férial Azziza Krid (Née Benyahia), Auteur ; M.N. Zidoune, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2013 Importance : 152 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : pepsine de poulet coagulation protéolyse rhéologie microstructure conservation chicken pepsin proteolysis rheology بيبسين الدجاج تخثير الحليب هدم البروتينات ريولوجيا حفظ البيبسين البنية المجهرية الدقيقة Index. décimale : 640 Industrie Alimentaire Résumé :
This study aimed the extraction of the pepsin from chicken proventriculus and characterization in order to ensure its use as a rennet substitute in the milk coagulation. For this purpose, we approached the study of its coagulant, proteolytic activities and biochemical, rheological and microstructural pepsin gel aspects with comparison to the rennet gel.
The chicken pepsin crude extract presented a strength coagulation of 13142. The partial purification by FPLC gave 45 fractions. The 18 fraction presented maximum coagulant activity (AC) and proteolytic activity (PA). The ration AC/AP of the pepsin crude extract increased from 7.15 to 34.25 after its partial purification. This increase is widely appreciated in cheese making.
The coagulant activity for chicken pepsin and rennet have been defined for temperature intervals included between 50 ° C and 55 ° C, pH 5.0 and 5.6 and 0.04 M CaCl2 respectively.
The coagulation was further estimated by the turbidimetry and the conductimetry. The turbidimetry showed similarity (p>0.05) between the micelles fusion evolution in the formation of the pepsin or rennet gel. However, the conductimetry has shown a difference (p< 0.05) between the minerals conductivity distributed between the aqueous and the micellar phase during gelation.
Rheological approach allowed to study the pepsin and rennet gel behavior by application of different shear rates. The apparent viscosity in non-destructive mode showed a similar viscous character evolution after, it tended to its maximum to indicate the formation of the two gels. Flow curves showed a plastic character for the two gels (Bingham liquid). On the other hand, the rennet gel seems to be viscoelastic ( = 0.55) relatively notable than gel pepsin ( = 0.60). The rennet and pepsin gels breaking points are reached respectively to 0.34 N and 0.38 N. Syneresis of the two gels showed at the beginning of coagulation rapid expulsion of whey. This expulsion tends to increase for gel pepsin but for rennet gel a stabilisation is shown for the same time of coagulation.
Proteolysis study was evaluated by the estimation of NPN/TN and NCN/TN fractions.
NPN fractions have not shown a significant difference (p> 0.05) ; 11.4% versus 11% for pepsin and rennet respectively. Nevertheless, the NCN fractions have presented differences (p<0.05) of 58.4 % for the pepsin gel and 49.8 % for the rennet gel.
In urea-PAGE, pepsin degradation products αs1I-CN and β I-CN of αs1-CN and et β-CN caseins respectively were observed in the early stages of incubation. Those of rennet appeared late from 6 hours of incubation. In SDS-PAGE, only para κ-CN was obtained as a κ-CN degradation product after pepsin or rennet hydrolysis.
The interactions study revealed the bonds type involved in the formation of two gels. The rate of their proteins dissociation showed an abundance in hydrophobic interactions, followed by
hydrogen and calcium bonds. The difference between the rate of dissociated proteins of two gels is
not significant (p>0.05).
The microscopic study of gels showed the evolution of the micelles fusion and the sol - gel system transition. Similarity of pepsin and rennet gels protein structure networks is visualized. This resemblance is characterized by compactness and the appearance of many cavities of heterogeneous size and amorphous zones. The spatial structure of two gels seems to be homogeneous.
To ensure stability of the chicken pepsin crude extract during a 135-day storage, two modes of drying were studied and compared, freeze-drying (lyophilization) and drying under
reduced vacuum. While the partial vacuum drying generated residual activity of 45.8% which decreased to 26.2% after 135 days of storage, freeze-drying ensured better results with 48.5% at the
end of drying operation and more than 41% for the same conservation period. The residual activity
seems to be better if the pepsinogen is activated after lyophilization. Furthermore, the addition of
lactose to the pepsin extract provides more interesting residual coagulant activity.
Theses results tend and converge towards the rennet substitution possibility by chicken pepsin in the milk coagulation. Also, it would be possible to use it in other areas for biological interest or industrial technology purposes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/BEN6636.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9770 Extraction de la pepsine et utilisation dans la coagulation du lait en vue d’une valorisation des proventricules de volailles au profit de la filière lait en Algérie [texte imprimé] / Férial Azziza Krid (Née Benyahia), Auteur ; M.N. Zidoune, Directeur de thèse . - constantine [Algérie] : Université Constantine 1, 2013 . - 152 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : pepsine de poulet coagulation protéolyse rhéologie microstructure conservation chicken pepsin proteolysis rheology بيبسين الدجاج تخثير الحليب هدم البروتينات ريولوجيا حفظ البيبسين البنية المجهرية الدقيقة Index. décimale : 640 Industrie Alimentaire Résumé :
This study aimed the extraction of the pepsin from chicken proventriculus and characterization in order to ensure its use as a rennet substitute in the milk coagulation. For this purpose, we approached the study of its coagulant, proteolytic activities and biochemical, rheological and microstructural pepsin gel aspects with comparison to the rennet gel.
The chicken pepsin crude extract presented a strength coagulation of 13142. The partial purification by FPLC gave 45 fractions. The 18 fraction presented maximum coagulant activity (AC) and proteolytic activity (PA). The ration AC/AP of the pepsin crude extract increased from 7.15 to 34.25 after its partial purification. This increase is widely appreciated in cheese making.
The coagulant activity for chicken pepsin and rennet have been defined for temperature intervals included between 50 ° C and 55 ° C, pH 5.0 and 5.6 and 0.04 M CaCl2 respectively.
The coagulation was further estimated by the turbidimetry and the conductimetry. The turbidimetry showed similarity (p>0.05) between the micelles fusion evolution in the formation of the pepsin or rennet gel. However, the conductimetry has shown a difference (p< 0.05) between the minerals conductivity distributed between the aqueous and the micellar phase during gelation.
Rheological approach allowed to study the pepsin and rennet gel behavior by application of different shear rates. The apparent viscosity in non-destructive mode showed a similar viscous character evolution after, it tended to its maximum to indicate the formation of the two gels. Flow curves showed a plastic character for the two gels (Bingham liquid). On the other hand, the rennet gel seems to be viscoelastic ( = 0.55) relatively notable than gel pepsin ( = 0.60). The rennet and pepsin gels breaking points are reached respectively to 0.34 N and 0.38 N. Syneresis of the two gels showed at the beginning of coagulation rapid expulsion of whey. This expulsion tends to increase for gel pepsin but for rennet gel a stabilisation is shown for the same time of coagulation.
Proteolysis study was evaluated by the estimation of NPN/TN and NCN/TN fractions.
NPN fractions have not shown a significant difference (p> 0.05) ; 11.4% versus 11% for pepsin and rennet respectively. Nevertheless, the NCN fractions have presented differences (p<0.05) of 58.4 % for the pepsin gel and 49.8 % for the rennet gel.
In urea-PAGE, pepsin degradation products αs1I-CN and β I-CN of αs1-CN and et β-CN caseins respectively were observed in the early stages of incubation. Those of rennet appeared late from 6 hours of incubation. In SDS-PAGE, only para κ-CN was obtained as a κ-CN degradation product after pepsin or rennet hydrolysis.
The interactions study revealed the bonds type involved in the formation of two gels. The rate of their proteins dissociation showed an abundance in hydrophobic interactions, followed by
hydrogen and calcium bonds. The difference between the rate of dissociated proteins of two gels is
not significant (p>0.05).
The microscopic study of gels showed the evolution of the micelles fusion and the sol - gel system transition. Similarity of pepsin and rennet gels protein structure networks is visualized. This resemblance is characterized by compactness and the appearance of many cavities of heterogeneous size and amorphous zones. The spatial structure of two gels seems to be homogeneous.
To ensure stability of the chicken pepsin crude extract during a 135-day storage, two modes of drying were studied and compared, freeze-drying (lyophilization) and drying under
reduced vacuum. While the partial vacuum drying generated residual activity of 45.8% which decreased to 26.2% after 135 days of storage, freeze-drying ensured better results with 48.5% at the
end of drying operation and more than 41% for the same conservation period. The residual activity
seems to be better if the pepsinogen is activated after lyophilization. Furthermore, the addition of
lactose to the pepsin extract provides more interesting residual coagulant activity.
Theses results tend and converge towards the rennet substitution possibility by chicken pepsin in the milk coagulation. Also, it would be possible to use it in other areas for biological interest or industrial technology purposes.Diplôme : Doctorat en sciences En ligne : ../theses/agronomie/BEN6636.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=9770 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/6636 BEN/6636 Thèse Bibliothèque principale Thèses Disponible Documents numériques
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Titre : Qualité de fromage à pâte molle type camembert fabriqué à la laiterie de Draa Ben Khedda : nature de la matière première et évaluation de l'activité protéolytique au cours de l'affinage et de l'entreposage réfrigéré du fromage. Type de document : texte imprimé Auteurs : Samia Abdoune (Née Ouali), Auteur ; M. Mati, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2003 Importance : 89 f. Note générale : 1 Disponible à la salle de recherche
02 Disponibles au magasin de la bibliothèque centrale
01 CDLangues : Français (fre) Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Sciences Alimentaires: Nutrition Appliquée Electrophorèse Lait Camembert Fromage Valeur nutritionnelle Protéolyse TNBS Pasteurisation milk cheese proteolysis electrophoresis refinement pasteurization nutritionnelle worth quality Index. décimale : 640 Industrie Alimentaire Résumé :
In the goal to appreciate faculties to the transformation produces some derivative of the mixture (cool milk / recombinated milk) used in our country as palliative to the deficit of the production in raw milk, we achieved tests of cheese manufacture to dough soft Camembert type in the Dairy of Draa Ben Khedda while especially interesting us to the assessment of proteolytic activity taking place during the phase of refinement and the storage refrigerated of this cheese. This activity is measured by the free amino grouping dosage (method using a specific reactif: the TNBS) and by the follow-up of casein behaviour electrophoretic in Page - Urea. The impact of the pasteurization treatment (85°C during 20 dry) on the milk of departure and the nature of this last have been examined also. The achieved analyses showed that the mixed milk (mixture to equal parts between
the cool milk and milk recombiné) permits, while correcting the rate weak proteic of the raw milk collected locally, to improve its value nutritional and its technological faculties. Nevertheless, electrophoretic pattern’s of seriqueses proteins in Page - Native as well as the soluble protein dosage after the treatment of pasteurization revealed a strong induced denaturation rate by this last and valued to about 30% in the case of milk recombiné used only. Concerning tea appreciation of tea refinement phase, however tea assessment of proteolytic activity is combinated to tea development of microorganisms, so much at tea level of tea superficial crust that in depth of tea derivative product tea gotten results showed that for tea two types of cheese considered (milk-based expenses solely however of tea mixed milk), tea proteolysis is pronounced more in surface that inside tea Camembert and this some either tea length of refinement considered. This activity, that is major after the sixth day of refinement, incomplete home after 12 days (time of maturation exercised to the unit. The extension of the refinement length at 15 and 210 days put besides in relief this insufficiency. Besides, the refrigerated storage doesn't seem to be a way appropriated for the characteristic organoleptiques expression searched for of the Camembert.Note de contenu :
Annexes.Diplôme : Magistère En ligne : ../theses/agronomie/ABD3880.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=4442 Qualité de fromage à pâte molle type camembert fabriqué à la laiterie de Draa Ben Khedda : nature de la matière première et évaluation de l'activité protéolytique au cours de l'affinage et de l'entreposage réfrigéré du fromage. [texte imprimé] / Samia Abdoune (Née Ouali), Auteur ; M. Mati, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2003 . - 89 f.
1 Disponible à la salle de recherche
02 Disponibles au magasin de la bibliothèque centrale
01 CD
Langues : Français (fre)
Catégories : Français - Anglais
Nutrition, Alimentation et Technologies Agro-AlimentairesTags : Sciences Alimentaires: Nutrition Appliquée Electrophorèse Lait Camembert Fromage Valeur nutritionnelle Protéolyse TNBS Pasteurisation milk cheese proteolysis electrophoresis refinement pasteurization nutritionnelle worth quality Index. décimale : 640 Industrie Alimentaire Résumé :
In the goal to appreciate faculties to the transformation produces some derivative of the mixture (cool milk / recombinated milk) used in our country as palliative to the deficit of the production in raw milk, we achieved tests of cheese manufacture to dough soft Camembert type in the Dairy of Draa Ben Khedda while especially interesting us to the assessment of proteolytic activity taking place during the phase of refinement and the storage refrigerated of this cheese. This activity is measured by the free amino grouping dosage (method using a specific reactif: the TNBS) and by the follow-up of casein behaviour electrophoretic in Page - Urea. The impact of the pasteurization treatment (85°C during 20 dry) on the milk of departure and the nature of this last have been examined also. The achieved analyses showed that the mixed milk (mixture to equal parts between
the cool milk and milk recombiné) permits, while correcting the rate weak proteic of the raw milk collected locally, to improve its value nutritional and its technological faculties. Nevertheless, electrophoretic pattern’s of seriqueses proteins in Page - Native as well as the soluble protein dosage after the treatment of pasteurization revealed a strong induced denaturation rate by this last and valued to about 30% in the case of milk recombiné used only. Concerning tea appreciation of tea refinement phase, however tea assessment of proteolytic activity is combinated to tea development of microorganisms, so much at tea level of tea superficial crust that in depth of tea derivative product tea gotten results showed that for tea two types of cheese considered (milk-based expenses solely however of tea mixed milk), tea proteolysis is pronounced more in surface that inside tea Camembert and this some either tea length of refinement considered. This activity, that is major after the sixth day of refinement, incomplete home after 12 days (time of maturation exercised to the unit. The extension of the refinement length at 15 and 210 days put besides in relief this insufficiency. Besides, the refrigerated storage doesn't seem to be a way appropriated for the characteristic organoleptiques expression searched for of the Camembert.Note de contenu :
Annexes.Diplôme : Magistère En ligne : ../theses/agronomie/ABD3880.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=4442 Exemplaires (1)
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