Etude des propriétés physico-chimiques et fonctionnelles du sirop de caroube

Le caroubier présente plusieurs intérêts pour toutes ses composantes, surtout pour ses fruits (gousses de caroube ou caroube). Plusieurs recherches scientifiques ont démontré que le fruit de caroube est riche en éléments nutritifs et composés phytochimiques. Ce qui explique son utilisation comme matière première pour la fabrication de divers produits, notamment le sirop de caroube. Certaines études ont été menées sur les caractéristiques physico-chimiques de ce produit, mais à notre connaissance, il n’y a pas encore des études scientifiques concernant ses propriétés fonctionnelles et son utilisation potentielle en industrie alimentaire. Donc, ce travail montre bien que le sirop de caroube possède des propriétés fonctionnelles intéressantes. Il présente une capacité émulsifiante (~80-87 %) comparable à celle de la lécithine de soja (~100 %), un émulsifiant largement utilisé dans les formulations alimentaires. Ce résultat révèle que le sirop de caroube peut être utilisé comme un émulsifiant alimentaire naturel pour la formation et la stabilité des émulsions

Biodrying process: a sustainable technology for treatment of municipal solid wastes organic fraction

[EN] The Municipal Solid Waste of Agareb (Sfax –Tunisia), characterized by high organic fraction and moisture contents is the most worrying pollution source that must be managed by innovative treatment and recycling technologies. Bio-drying, as a waste to energy conversion technology, aims at reducing moisture content of this organic matter. This concept, similar to composting, is accomplished by using the heat generated from the microbial degradation of the waste matrix, while forced aeration is used. The purpose of this work was to reduce the moisture content of the waste, by maximizing drying and minimizing organic matter biodegradation, in order to produce a solid recovered fuel with high calorific value.Kechaou, N.; Ammar, E. (2018). Biodrying process: a sustainable technology for treatment of municipal solid wastes organic fraction. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1953-1960. https://doi.org/10.4995/IDS2018.2018.7842OCS1953196

Comparative study between carob and date syrups

Date and carob syrups are traditional foods produced and consumed in several countries, including Tunisia. Each syrup is characterized by its interesting nutritional and bioactive composition. Several studies have been carried out on the production and characterization of each syrup separately, but this study tends to compare the aromatic, physico-chemical, nutritional and functional properties of commercial carob and date syrups. The results showed a comparable aromatic composition whose major compounds are terpenes (carvone and menthol), a difference in color since carob syrup was characterized by a darker brown color, a nutritional composition rich in sugars and a difference in functional properties since carob syrup had greater emulsifying capacity and antioxidant activity. Thus, the characteristics of carob and date syrups encourage their use in the food industry according to the appropriate product

Strawberries hybrid drying combining airflow, dic technology and intermittent microwaves

[EN] 1-cm strawberry slices were partially airflow-dried at 50 °C, to reach 0.25 g H2O/g db. Optimized DIC treatment was performed at 350 kPa for 10 s. The final drying stage of these DIC-expanded slices was achieved from 0.25 to 0.1 g H2O/g db (dry basis) using intermittent Pulsed Micro-Wave Drying PMWD to prevent from the paradoxical step of coupled conduction heat transfer with deep generation and transfer of vapor. PMWD was defined at constant 100 W for 3.25±0.05 g with constant active time ton maintained at 2 s, and tempering time toff ranged between 2 and 10 s, or with a continuous way. By decreasing both energy consumption and total drying time of DIC-expanded slices using intermittent microwave, the whole cost significantly decreased to be much lower than the conventional MWD drying, with a great increasing of the quality.Amami, E.; Besombes, C.; Kechaou, N.; Allaf, K. (2018). Strawberries hybrid drying combining airflow, dic technology and intermittent microwaves. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1639-1646. https://doi.org/10.4995/IDS2018.2018.7556OCS1639164

Evaluation of bioactive compounds and biological activities of Tunisian propolis

The aim of this study was to investigate the phytochemical composition and biological properties of Tunisian propolis from four different regions: Kasserine, Béja, Kèf and Monastir. Ethanolic extracts of propolis were prepared using two extraction methods; solvent and ultrasonic extraction. Total phenolics, flavonoids, ABTS free radical and hydroxyl radicals scavenging abilities, anti-inflammatory, anti-hypertensive, as well as antimicrobial activities of propolis extracts were determined. Identification and quantification of phenolic and flavonoid compounds were performed by using both HPLC-UV and HPLC-ESI-MS. The results revealed high contents of total phenolics and flavonoids and polyphenols extraction was more efficient by sonication. Caffeic acid phenethyl ester (CAPE), galangin, and genistein were the major identified compounds. Antihypertensive activity, evaluated in propolis extracts for first time by HPLC-UV, was higher than 90% for all extracts. Tunisian propolis is an important natural source of polyphenols and flavonoids. The best extraction method was ultrasonic for antioxidants and most of biological activities; conventional method seems to be more suitable for anti-inflammatory activity. Propolis from Béja contains the highest amount of antioxidants and have a stronger potential biological activities. Tunisian propolis could be, therefore, a promising raw material for food and pharmaceutical industry

Modeling and Thermodynamic Study of Water Vapor Desorption Isotherms of Orange Peel and Leaves using Statistical Physics Treatment

The shelf life and safety of food products is related to the water content, in particular to the water activity (aw). This is important to predict the physical, chemical and biological processes that take place during food storage. Analytical expression for modeling water desorption isotherms of food is developed using the grand canonical ensemble in statistical physics. The model is further applied to fit and interpret the desorption isotherms of water vapor on the orange peel and leaves at three different temperatures. In the developed model we introduce essentially six parameters such as the number of adsorbed water molecules per site, the number of adsorbed layers, the energy of desorption and receptor sites density. We interpret the results of fitting then we apply the model to calculate thermodynamic functions which govern the desorption mechanism such as internal energy and entropy

Purification and biochemical characterization of a novel thermostable protease from the oyster mushroom Pleurotus sajor-caju strain CTM10057 with industrial interest

Background Proteases are hydrolytic enzymes that catalyze peptide linkage cleavage reactions at the level of proteins and peptides with different degrees of specificity. This group draws the attention of industry. More than one protease in three is a serine protease. Classically, they are active at neutral to alkaline pH. The serine proteases are researched for industrial uses, especially detergents. They are the most commercially available enzyme group in the world market. Overall, fungi produced extracellular proteases, easily separated from mycelium by filtration. Results A new basidiomycete fungus CTM10057, a hyperproducer of a novel protease (10,500U/mL), was identified as Pleurotus sajor-caju (oyster mushroom). The enzyme, called SPPS, was purified to homogeneity by heat-treatment (80 C for 20min) followed by ammonium sulfate precipitation (35-55%)-dialysis, then UNO Q-6 FPLC ion-exchange chromatography and finally HPLC-ZORBAX PSM 300 HPSEC gel filtration chromatography, and submitted to biochemical characterization assays. The molecular mass was estimated to be 65 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Native-PAGE, casein-zymography, and size exclusion by HPLC. A high homology with mushroom proteases was displayed by the first 26 amino-acid residues of the NH2-terminal aminoacid sequence. Phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP) strongly inhibit SPPS, revealing that it is a member of the serine-proteases family. The pH and temperature optima were 9.5 and 70 C, respectively. Interestingly, SPPS possesses the most elevated hydrolysis level and catalytic efficiency in comparison with SPTC, Flavourzyme 500 L, and Thermolysin type X proteases. More remarkably, a high tolerance towards organic solvent tolerance was exhibited by SPPS, together with considerable detergent stability compared to the commercial proteases Thermolysin type X and Flavourzyme 500 L, respectively. Conclusions This proves the excellent proprieties characterizing SPPS, making it a potential candidate for industrial applications especially detergent formulations

Etude des propriétés physico-chimiques et fonctionnelles du sirop de caroube

Le caroubier présente plusieurs intérêts pour toutes ses composantes, surtout pour ses fruits (gousses de caroube ou caroube). Plusieurs recherches scientifiques ont démontré que le fruit de caroube est riche en éléments nutritifs et composés phytochimiques. Ce qui explique son utilisation comme matière première pour la fabrication de divers produits, notamment le sirop de caroube. Certaines études ont été menées sur les caractéristiques physico-chimiques de ce produit, mais à notre connaissance, il n’y a pas encore des études scientifiques concernant ses propriétés fonctionnelles et son utilisation potentielle en industrie alimentaire. Donc, ce travail montre bien que le sirop de caroube possède des propriétés fonctionnelles intéressantes. Il présente une capacité émulsifiante (~80-87 %) comparable à celle de la lécithine de soja (~100 %), un émulsifiant largement utilisé dans les formulations alimentaires. Ce résultat révèle que le sirop de caroube peut être utilisé comme un émulsifiant alimentaire naturel pour la formation et la stabilité des émulsions

Comparative study between carob and date syrups

Date and carob syrups are traditional foods produced and consumed in several countries, including Tunisia. Each syrup is characterized by its interesting nutritional and bioactive composition. Several studies have been carried out on the production and characterization of each syrup separately, but this study tends to compare the aromatic, physico-chemical, nutritional and functional properties of commercial carob and date syrups. The results showed a comparable aromatic composition whose major compounds are terpenes (carvone and menthol), a difference in color since carob syrup was characterized by a darker brown color, a nutritional composition rich in sugars and a difference in functional properties since carob syrup had greater emulsifying capacity and antioxidant activity. Thus, the characteristics of carob and date syrups encourage their use in the food industry according to the appropriate product

Valorisation des écarts de triage de dattes par séchage pour l'obtention d'une poudre pour alimentation animale

The interest of this study is to recover the date's by-products the most common in Tunisia by applying the drying process. The product is getting to be a powder for animal feed. The physicochemical analysis of raw materials showed that dates have a high content of soluble sugars and polysaccharides. The study of dates drying at 50, 60 and 70°C showed that the temperature rises more drying time is reduced. Indeed, dates have initial moisture content of around 0.38kg/kg DM and become stable at the end of drying to moisture content of about 0.15kg/kg DM. The physico-chemical composition of the dates powders at different temperatures show that they are rich in soluble sugars and polysaccharides, high levels of potassium and magnesium and law protein, crude fiber and fat content.L'intérêt de cette étude consiste à valoriser les écarts de triage des dattes (noyau+pulpe) les plus répandus en Tunisie par application du procédé de séchage. Le produit visé est l'obtention d'une farine qui sera destinée à l'alimentation animale. L’analyse physicochimique de la matière première a montré que les écarts de triage des dattes présentent une teneur élevée en sucres solubles et en polysaccharides. L'étude de séchage des dattes à 50, 60 et 70°C a montré que plus la température augmente plus la durée de séchage est réduite. En effet ; les écarts de triage de dattes ont une teneur en eau initiale aux alentours de 0,38 kg/kg MS et deviennent stables à la fin du séchage à une teneur d'humidité de l'ordre de 0,15 kg/kg MS. La composition physico-chimique des poudres de dattes séchées à différentes températures montrent que ces dernières sontriches en sucres solubles et en polysaccharides et ont des teneurs élevés en potassium et en magnésium et présentent des faibles teneurs en protéines, en cellulose brute et en matières grasses