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关键词： Polyimides   k(app)   R6G dye   Catalysis   Cr(VI)  

摘要： Synthesis of Polyimides (PIs) between pyromellitic dianhydride (PMDAH) and oxydianiline (ODA) or p-phenylenediamine (PPDA) in the presence and absence of V2O5 and Ag nanoparticles (NPs) were carried out under N-2 atmosphere at 160 degrees C for 5 h with vigorous stirring in N-methylpyrrolidone (NMP) solvent. The prepared PI and its nanocomposites were analyzed by FT-IR spectroscopy, H-1 NMR spectroscopy, FE-SEM, SEM, DSC and TGA like analytical instruments. The FE-SEM showed various surface morphologies for different PI nanocomposites. The particle size of the prepared nanoparticles was calculated as less than 60 nm for Ag and 15 nm for V2O5 nanoparticles by HR-TEM. The PI nanocomposites embedded with Ag nanoparticles (P2 and P5) showed a higher thermal stability than the pristine PIs (P1 and P4) and PI/V2O5 nanocomposites (P3 and P6). Further, the possible application of metal (Ag) and metal oxide (V2O5) NPs embedded PI nanocomposites was assessed on the catalytic reduction of highly toxic Cr(VI), Rhodamine 6G (R6G) dye and p-nitrophenol (NiP) pollutants with the help of a reducing agent (NaBH4). The apparent rate constant (k(app)) values were calculated to assess the catalytic efficiency of the prepared PI and its nanocomposites. The PI/Ag nanocomposite (P2) system showed an efficient catalytic reduction than the other systems. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Soybean   Cotyledons   Flour   Cellular integrity   Boiling   Protein physicochemical properties   Protein digestion  

摘要： Previous studies showed that in vitro digestibility of proteins in cooked beans is modulated by heat treatment and that the effect may be different whether proteins are heated in intact cotyledon or in a bean flour. In this study, germinated and non-germinated soybean cotyledons and flour were boiled at 100 degrees C for varying times (30, 90, or 180 min). After grinding, the level of trypsin inhibitors, protein aggregation, surface hydrophobicity, the secondary structure, and in vitro digestibility were studied. The presence of an intact cell wall during cooking increased protein denaturation temperature by about 10% and reduced the denaturation of trypsin inhibitors, and induced distinct changes in protein surface hydrophobicity and secondary structure. These physicochemical properties translated into an increment in protein degree of hydrolysis (DH, 72%) of protein cooked for 30 min as flour compared to proteins cooked in intact soybean tissues (64%). Increase in cooking times (90 and 180 min) resulted in limited improvement in the protein digestibility and changes in protein physicochemical properties for both boiled cotyledons and flour. Soybean germination resulted in distinct changes in protein physicochemical properties and higher protein DH% of raw soybean (61%) compared to non-germinated raw soybean (36%). An increase in protein digestibility of germinated soybean was also observed after boiling for both cotyledon and flour. However, significant differences in DH% were not observed between proteins boiled in intact cotyledon and in a flour. This work provides extra knowledge of the role of cellular integrity on protein properties in plant foods and suggests that germination or grinding before cooking may increase protein digestibility.

关键词： Alkali‐   soaking   limewater   physicochemical property   rice flour   washing treatment  

摘要： Effects of alkaline [NaOH, saturated Ca(OH)(2) and/or limewater] soaking and subsequent washing (with water vs. without washing) treatments on physicochemical properties of rice flour were investigated. Alkaline soaking treatment generally caused a loss of granule angularity but some birefringence was observed for unwashed alkali-soaked flour granules. After soaking, protein content of the flours significantly (P < 0.05) decreased but swelling power significantly (P < 0.05) increased compared to the control (soaked in water). The washed flours had lower protein content than unwashed flours (3.77-6.87% vs. 5.26-7.87%). The NaOH-soaking treatment yielded higher swelling power and solubility, respectively, for unwashed and washed flours. Alkaline soaking increased breakdown but decreased pasting temperature, trough viscosity, final viscosity and setback of the paste compared to the control. Compared to the control, hardness of soaked flour paste was lower due to lower final viscosity and setback. Overall, physicochemical properties of rice flour could be modified by alkali-soaking and washing treatments.

关键词： Fatty acids  

摘要： The use of starter cultures in the industrial manufacture of meat products has become common practice. We have investigated the use of Lactobacillus sakei F, isolated from a commercial starter culture, and Lactobacillus sakei 23K, from a French sausage, alone or together with Staphyloccus xylosus, as starter cultures, during the industrial manufacture of Tunisian dry-fermented sausages. Samples from the same raw matter were collected after up to 45 days of maturation and were subjected to microbiological, physicochemical, nutritional, and sensory analyses. Furthermore, we demonstrated that the use of L. sakei F or L. sakei 23K as starter strains produced a fermented sausage with similar or even better quality than sausages fermented with L. sakei 23K + S. xylosus or the commercial starter. Our study found that L. sakei 23K could have a great potential for use as a starter culture during the commercial production of dry-fermented sausage. Novelty impact statement Lactobacillus sakei F and 23K strains can be used alone or in association with Staphylococcus xylosus as starter cultures for the manufacture of Tunisian dry-fermented sausages. Sausages produced with L. sakei F and 23K strains display better nutritional and sensory profiles, compared with the non-inoculated controls, as well as sausages inoculated with the commercial starter culture.

关键词： Activated carbon   Ball milling   Adsorption kinetics   Isotherm model   Thermodynamics  

摘要： This study investigates the short time ball milling effect on surface properties of activated carbon. (AC) produced from mangosteen peels (MP) waste and its subsequent effects on adsorption of cationic methylene blue (MB) from aqueous solution. AC was synthesized from MP waste under mild experimental conditions and was ball milled for a short time (30 min-120 min) at 350 rpm. The physicochemical properties of ball milled AC (BMAC) were investigated using BET, FTIR, TGA, FESEM, XRD and particle size distribution analysis. Various experimental results revealed that MB adsorption on BMAC was greatly influenced by basic pH, contact time and high temperature. The adsorption capability of BMAC was found to increase with decreasing particle size with ball milling. Kinetics study revealed that the adsorption capability of BMAC was best represented by pseudo second order kinetic model and adsorption equilibrium was well described by Langmuir isotherm. The adsorption process was endothermic and spontaneous as revealed by thermodynamic study. Overall, this work demonstrated that ball milling decreases the particle size of AC, increased its efficiency for adsorption of dye, and opened new ways for activation of AC using the ball-milling technique. (c) 2020 Elsevier Ltd. All rights reserved.

关键词： Bifidobacteria   free‐   lactose milk   gastrointestinal simulation   inulin   microencapsulation   oligofructose  

摘要： Bifidobacterium BB-12 was microencapsulated by spray drying using lactose-free milk, lactose-free milk and inulin, and lactose-free milk and oligofructose, resulting in powders 1, 2 and 3, respectively. The highest encapsulation yield (88.01%) and the highest bifidobacteria viability during 120 days of storage were noted for spray-dried powder 2. Spray-dried powders 1 and 3 show a higher tendency to yellow colour. After being submitted to in vitro-simulated gastrointestinal conditions, the best probiotic survival rate result was found for spray-dried powder 3 (87.59%). Therefore, spray-dried powders containing prebiotics were the most appropriate combinations for microencapsulation of Bifidobacterium BB-12 and maintenance of cell viability during storage and gastrointestinal system, showing great potential to be used in lactose-free dairy products.

关键词： potassium forms   calcareous soils   K release   clay minerals  

摘要： Experiments were conducted for thirty representative surface and subsurface soils collected from different physiographic units and moisture regimes in southern Iran to assess factors affecting K pools distribution and potassium release rate, using two organic and inorganic extractants and their association to mineralogy and some physical and chemical properties in calcareous soils. Mineralogical analysis indicated that illite, smectite, chlorite and palygorskite were the main clay minerals in the studied soils. The highest content of illite and smectite was observed in the piedmont plain (P.P) units, whereas that of smectite in Lowland (L.L) unit was higher than in soils of alluvial fans (A.F). It seems that the P.P unit which is in more stable landform position contains larger amounts of all K compounds due to higher clay and illite contents. The exchangeable, non-exchangeable (NEK), structural, and total potassium were found to be significantly and positively correlated to the clay content, cation exchange capacity, and the contents of illite, smectite, and vermiculite minerals, while a negative correlation as observed between the mentioned K forms and the calcium carbonate (CaCO3) content. The cumulative rate of K release to 0.01 M CaCl2 and oxalic acid was examined for a period of 1200 h, ranging within 104-286 and 87-233 mg kg(-1) for the surface soil and 98-241 and 82-211 mg kg(-1) for the subsurface soil samples, respectively. The percentage of non-exchangeable K released varied greatly between the different units and moisture regimes. Higher values of NEK release were observed for P.P followed by A.F, and L.L units. Considering the obtained values of the highest amount of potassium compounds as well as the release values in the piedmont plain physiographic unit and the xeric moisture regime as well as the Alfisols, the results confirm that in addition to physicochemical and mineralogical properties, physiographic units and soil moisture regimes also play a k

关键词： cisplatin   lymph node metastasis   lymphatic drug delivery system   osmotic pressure   viscosity  

摘要： Lymph node (LN) metastasis is thought to account for 20-30% of deaths from head and neck cancer. The lymphatic drug delivery system (LDDS) is a new technology that enables the injection of drugs into a sentinel LN (SLN) during the early stage of tumor metastasis to treat the SLN and secondary metastatic LNs. However, the optimal physicochemical properties of the solvent used to carry the drug have not been determined. Here, we show that the osmotic pressure and viscosity of the solvent influenced the antitumor effect of cisplatin (CDDP) in a mouse model of LN metastasis. Tumor cells were inoculated into the proper axillary LN (PALN), and the LDDS was used to inject CDDP solution into the subiliac LN (SiLN) to treat the tumor cells in the downstream PALN. CDDP dissolved in saline had no therapeutic effects in the PALN after it was injected into the SiLN using the LDDS or into the tail vein (as a control). However, CDDP solution with an osmotic pressure of similar to 1,900 kPa and a viscosity of similar to 12 mPa.s suppressed tumor growth in the PALN after it was injected into the SiLN using the LDDS. The high osmotic pressure dilated the lymphatic vessels and sinuses to enhance drug flow in the PALN, and the high viscosity increased the retention of CDDP in the PALN. Our results demonstrate that optimizing the osmotic pressure and viscosity of the solvent can enhance the effects of CDDP, and possibly other anticancer drugs, after administration using the LDDS.

关键词： Whey powder   Edible film   Demineralisation ratio   Tensile strength  

摘要： The effects of using whey powders with different demineralisation rates on the physicochemical, thermal, mechanical, and microstructural properties of gelatine-based edible films were investigated. Films were produced from film-forming solutions (FFS) containing whey powder (WP) and 50, 70 and 90% demineralised whey powder (50DWP, 70DWP, 90DWP). The addition of whey powders increased the pH and particle size values of FFS. The zeta potential decreased significantly in the WP sample and gradually reduced depending on the demineralisation rate in the DWP samples. The addition of whey powders partially increased the density of the films. WP addition reduced the hydrophobicity of the film, while the addition of DWPs did not cause any change. The addition of whey powders decreased the L* and a* values of the films while increasing the b* values. Control was the most transparent, while 70DWP and 90DWP films had higher opacity. WP films had the most uniform and smooth surface. The highest degradation temperature (269.64 degrees C) was observed in the control sample. The weight loss of the control was 95%, whereas those of WP and DWP samples were 88-89%. WP addition reduced the tensile strength and increased the elasticity of the films.

关键词： Ambroxol hydrochloride   Bromhexine hydrochloride   Solubility   Local composition model   Acid dissociation constant   Thermophysical properties  

摘要： Two widely used active pharmaceutical ingredients (API), ambroxol hydrochloride (AMB center dot HCl) and bromhexine hydrochloride (BMH center dot HCl), belong to the expectorant and mucokinetic group of drugs. Their applications are found in the treatment of the upper respiratory tract and bronchopulmonary diseases. The compounds have similar chemical structures, but are different enough to distinguish their physicochemical properties. To understand better the bioavailability of the drugs a series of experiments was performed to establish significant parameters. With differential scanning calorimetry (DSC) the temperature and the enthalpy of fusion were determined with no observed polymorphic transformations. The phase diagrams for binary systems {active agent (1) + solvent (2)} were determined with three solvents: 1-octanol, water and ethanol, to describe phase equilibria by correlation with the local composition models: Wilson, UNIQUAC and NRTL. Finally, the Bates-Schwarzenbach method was used to establish the ionization constants of AMB center dot HCl and BMH center dot HCl at two temperatures: room temperature 298.2 K and human body temperature 310.2 K. Our study can give an insight into further drug delivery system design and help to create more effective drug application forms.