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关键词： Protein gel   Gadus morhua   Homogenize   Protein cross-linking   Intermolecular forces  

摘要： Cod cut offs, as a by-product of cod processing, is often discarded and wasted. A cod protein gel (CP-gel) was produced from homogenized steamed cod cut offs to turn the otherwise "waste" into treasure. The effects of homogenizing conditions on the physicochemical properties of the CP-gel were investigated by assessing the gel strength, water holding capacity (WHC), rheological properties and microstructure, combined with the visual appearance. After homogenization at 80 MPa with 15 passes, the particle size was reduced to 4 mu m and resulted in a gel strength of 0.63 N. The WHC of cod protein gel increased by 41% as compared to the un-homogenized sample. The secondary structures of the microfibrillar proteins changed as evidenced by the increased alpha-helix content by 3% via homogenization. The reduced particle size allowed particle-particle interactions and promoted protein cross-linking via both hydrophobic interaction and hydrogen bond formation. A relatively smooth and honeycombed network structure was formed with improved gel quality and physical properties. CP-gel provides a potential to utilize cod cut offs to produce value-added products.

关键词： Coconut inflorescence sap   Neera   Kalparasa   Fermentation   Palm sap   Reaction kinetics  

摘要： The study on fermentation kinetics of the coconut inflorescence sap is important to understand its shelf life at different storage conditions and to develop suitable value added products. The coconut inflorescence sap collected by using in-house developed coco-sap chiller device is called Kalparasa. The fermentation characteristics of Kalparasa were investigated at every 1-h interval under ambient (31 +/- 2 degrees C) and refrigerated (5 +/- 1 degrees C) storage conditions. The results reveal that pH of the sap and total sugar content decline rapidly under ambient conditions than under refrigerated conditions. Acidity, turbidity, and reducing sugar content significantly (p < 0.001) increases for the sap stored under ambient conditions. The reaction rate constant (k) of the vitamin C and total sugar degradation increases with the atmospheric fermentation. The degradation kinetics of vitamin C and total sugar in Kalparasa during natural fermentation (ambient condition) follow second-order equation whereas the reducing sugar follows the first-order equation.

关键词： bismuth titanates   solid-state synthesis   crystal structure   luminescence   high-temperature heat capacity   phase transition  

摘要： Bi4-xPrxTi3O12 (x = 0.4, 0.8, 1.2, 1.6) solid solutions have been prepared by solid-state reactions, via multistep firing of stoichiometric mixtures of their constituent oxides in air at temperatures from 1003 to 1323 K. Their crystal structure has been determined using X-ray diffraction, and their luminescence spectra have been measured at room temperature. High-temperature heat capacity of polycrystalline substituted bismuth titanate samples has been determined by differential scanning calorimetry. The C-p(T) curves of the solid solutions with x = 0.4 and 0.8 have extrema related to phase transitions. Experimental data have been used to calculate the main thermodynamic functions of the solid solutions.

关键词： Reservoirs   Physicochemistry   Rotifers   Trophic state   Biotic index   Water quality  

摘要： The aim of this study is to examine the trophic state of three reservoirs located in the northwest of Algeria based on the physicochemistry of water and the community of rotifers. The measurements of the physicochemical variables were carried out monthly over a 2-year period from December 2015 to November 2017. The rotifers were sampled simultaneously. Abiotic and biotic indices such as the Carlson index,Q(B/T), and TSI(ROT)were determined in order to classify the three reservoirs according to their trophic state. Thus, the diversity indices of Shannon-Wiener (H '), Margalef richness index (D), Pielou evenness (J '), and the density were calculated in order to study the structure of the rotifers. The Kruskal-Wallis test confirmed the heterogeneity of the physicochemical quality (Pvalue < 0.05) among the three reservoirs. A total of 71 species were identified during this study. The result of the various indices affirms this heterogeneity and indicates a trophic state hypereutrophic for the Hammam Boughrara reservoir, eutrophic for the Bakhadda reservoir and meso-oligotrophic for Sidi Yacoub. The use of canonical correspondence analysis (CCA) has shown that the structure of rotifers is influenced by local environmental factors. Some species such as the genusBrachionusspecies have shown their preference for extreme conditions. The use of biotic indices is highly recommended for the trophic state evaluation of reservoirs for a better water resources management.

关键词： Fish  

摘要： The present study aims at developing fish flour from two small indigenous fish species, that is, Puntius sophore and Amblypharyngodon mola. Fish flour developed from fresh fish species were analyzed for their nutritional compositions following standard protocols. Results indicated the protein, ash, calcium, phosphorus, potassium, magnesium, and iron content to be 55.15 +/- 0.71 g/100 g, 18.14 +/- 0.69 g/100 g, 1,850.34 +/- 2.40 mg/100 g, 799.17 +/- 1.50 mg/100 g, 653.26 +/- 0.64 mg/100 g, 331.02 +/- 2.11 mg/100 g, and 16.00 +/- 1.29 mg/100 g, respectively, for fish flour developed from Puntius sophore and 61.32 +/- 0.31 g/100 g, 15.43 +/- 0.45 g/100 g, 2098.40 +/- 2.37 mg/100 g, 1,012.81 +/- 3.86 mg/100 g, 413.78 +/- 1.47 mg/100 g, 256.82 +/- 1.65 mg/100 g, and 12.53 +/- 0.52 mg/100 g, respectively, for fish flour developed from Amblypharyngodon mola. The developed flours also had good functional properties with bulk density, water absorption capacity and fat absorption capacity of 0.52 +/- 0.001 g/ml, 121.67 +/- 2.89 ml/100 g, and 81.67 +/- 2.89 ml/100 g, respectively, for Puntius sophore and 0.57 +/- 0.01 g/ml, 119.67 +/- 4.51 ml/100 g, and 65.00 +/- 5.00 ml/100 g, respectively, for Amblypharyngodon mola. Practical applications The edible fish flour developed from small indigenous fish species can serve as a good source of protein and minerals for children, adolescence, and individuals of other age groups. Due to its high protein content, it could be used commercially as protein supplement. It can also serve as a potential ingredient by various food processing industries for value addition of low protein snacks. In addition, it would also improve the utilization of small fish species thereby generating a source of livelihood for people living close to water bodies.

关键词： Polishing   Milling characteristics   Proximate composition   Mineral composition   Component loss rates   Colorimetric analysis  

摘要： The milling characteristics, physico-chemical properties, nutrient, and functional characteristics of sorghum were evaluated following field-level abrasive decortication to ascertain the impact of polishing parameters. Both grain moisture content and polishing time were found to significantly influence the degree of polish, endosperm yield, percentage broken, grain hardness, and thousand-grain weight. Both the proximate composition and mineral content of the flour decreased owing to decortication, indicating their dominant presence in the bran fractions. A more significant reduction in tannins was observed as compared to phytates meaning that phytates might be more localized in the inner layers, and tannins are majorly concentrated in the outer grain portions. Whole grain flour possessed better water and oil absorption capacities and lower bulk density value compared to polished fractions. There was also an increase in L* (lightness) and decrease in a* (red to green) and b* (yellow to blue) values in the polished flour samples indicating that decortication results in an overall improvement of the color of refined fractions. Results of PCA suggested a significant correlation between certain components namely fibre contents and tannin, ash content and mineral contents, and fibre and water absorption capacity, signifying that they co-vary with respect to one another. The cluster analysis suggested the importance of selected variables and their impact on the responses, as a clear demarcation was seen in the samples obtained from raw and polished grains.

关键词： tetracycline   adsorption   grand canonical formalism   physicochemical parameters   pore size distribution  

摘要： The isotherms of adsorption of tetracycline on activated carbon obtained from Agave Americana fibers were analyzed using the method of statistical physics. It was shown that the adsorption of tetracycline molecules on such coal was a multimolecular process. The share of tetracycline molecules that filled the sites of the first type was 2-5 times higher than the second, because the adsorption energy in the sites of the first type was 0.6-2 kJ/mol lower (at temperatures of 298-323 K, respectively). Using the dispersion equation, it was shown that the tetracycline molecules were adsorbed in the micropores and mesopores of activated carbon with a pore size lower than 2 nm.

关键词： Electrolyte   Hydrodynamic radius   Lonicity   NCA   Li-ion battery  

摘要： Herein we present a comparative study of the physicochemical and thermal properties of four electrolytes formulated with LiTFSI, LiFSI in binary (3EC/7EMC) and ternary (EC/PC/3DMC) mixture of solvents, as a function of salt concentration and temperature. By modeling the change on viscosity, ionic conductivity, with Arrhenius, Eyring and Jones-Dole-Kaminsky equations, we established the determinants parameters which influence the organization of solutions, in order to understand their consequences on electrochemical performances of LiNi0.8Co0.15Al0.05 (NCA) as cathode in Li-ion battery. Results shown that (3EC/7EMC + LiTFSI) present a double solvation sphere of Li+ and weak ionic association consequently it is poorly suited to the activation and cycling of NCA. While (EC/PC/3DMC + LiFSI) benefits from both a single sphere of solvation and strong ion-ion and ion-solvent interactions, making the polarization of the interfaces in this electrolyte suitable to the Li+ diffusion and to low interface resistances. These results demonstrate that the electrolyte properties such as viscosity, conductivity and thermal stability depend on several factors. Those related to species in solutions (solvents and salt ions), and those related to operating conditions such as temperature and concentration. All these parameters impact the ionic dissociation and solvation. This study shows the close-link between the organization of species in solutions, the physicochemical and thermal properties, and their impact on electrochemical performances in a Li-ion battery. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Degree of conversion   Mechanical properties   Polymerisation   Amine  

摘要： Objective. To assess the mechanical properties of two different dimethacrylate resin blends containing the photosensitizer camphorquinone (CQ) alone or in combination with one or more synergists including an amine and/or an iodonium. Methods. Two co-monomer resin blends were formulated using Bis-GMA/TEGDMA and UDMA/TEGDMA, both at 1:1 mass ratio. Each resin blend was divided into four groups, comprising the following four photoinitiation systems: (1) CQ + 2-(dimethylamino)ethyl methacrylate (DMAEMA);(2) CQ + DMAEMA + bis(4-methyl phenyl)iodonium hexafluorophosphate (BPI);(3) CQ;and (4) CQ + BPI. Materials were evaluated for polymerisation kinetics, water sorption, solubility, flexural strength and modulus. Results. BisGMA/TEGDMA with CQ showed minimal and insignificant degree of conversion and was not tested for water sorption/solubility and mechanical properties. The ternary system (i.e., CQ + DMAEMA + BPI), promoted the highest degree of conversion for each monomer blend. The resins containing amine had higher mechanical properties than the amine free. However, the UDMA amine free resins exhibited greater flexural strength and modulus than the corresponding amine free BisGMA resins. BisGMA/TEGDMA containing CQ + DMAEMA or CQ + BPI had significantly higher water sorption and solubility than the other groups. Significance. Resins containing amine presented better properties than the amine-free systems. The addition of iodonium salt (BPI) improved the degree of conversion of the resins, even without an amine co-initiator. The amine-free initiator system (CQ + BPI) was more effective when used with UDMA versus BisGMA based-resins respectively. (c) 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

关键词： Bacillus tequilensis   Surfactin   Iturin   Emulsifying properties   Surfactant properties   Antifungal properties  

摘要： A new biosurfactant was obtained from a moderately halophilic bacterium identified as Bacillus tequilensis ZSB10 that was isolated from a saline water pond located in Tehuacan-Cuicatlan valley, Mexico. A kinetic analysis of the bacterial growth of the ZSB10 strain showed a maximum growth at 24 h regardless of the initial pH (5, 7.4, and 9). The best results were found at pH = 7.4 in terms of bacterial growth, besides which the produced biosurfactant showed emulsifying and surfactant properties with an emulsification index (E-24) and surface tension change (Delta ST) of 54 +/- 0% and 26 mN m(-1), respectively. Extracted ZSB10 crude biosurfactant had a yield of 106 +/- 6 mg L-1, an E-24 = 58.4 +/- 0.2%, and a Delta ST = 26 mN m(-1) with a critical micelle concentration (CMC) of 44.82 mg L-1. Also, its structure was characterized by MALDI-TOF mass spectrometry as a surfactin, iturin A, and fengycin mixture whose main isoform was leu/ile-7 C-15 surfactin [M + Na](+). Finally, the ZSB10 crude biosurfactant showed antifungal activity against Helminthosporium sp., with a 79.3% growth inhibition and an IC50 of 1.37 mg per disc. Therefore, this biosurfactant could be used as biopesticide.