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关键词： g-ZnS@GO@CS ternary hybrid   green synthesis   optical properties   thermal stability   antibacterial activity  

摘要： In this study, green-ZnS nanoparticles (g-ZnS NPs) were synthesized via chemical precipitation using aqueous solutions of ZnCl(2)and Na2S at the presence of green tea solution. The ternary hybrid nanocomposite of green-ZnS@ Graphen oxide@Chitosan (g-ZnS@GO@CS) was also prepared throughin situchemical deposition of g-ZnS nanoparticles on GO@CS composite. The obtained nanostructures were characterized by FTIR, SEM, XRD, EDX, X-map, photoluminescence (PL), TGA, and UV-DRS analyses. Based on the results, the g-ZnS@GO@CS composite possessed cauliflower morphology in which ZnS NPs were homogeneously distributed on the composite matrix. Crystallographic investigations revealed the fcc phase of ZnS NPs. Moreover, the crystallite sizes of ZnS, g-ZnS, and g-ZnS@GO@CS samples were estimated as 28.8, 17.9, and 14.8 nm, respectively. Using UV-vis spectroscopy, the bandgap energy of g-ZnS@GO@CS composite, pure ZnS, and g-ZnS were determined 3.02, 3.37, and 4.42 eV, respectively;suggesting a significant reduction in the bandgap of the composite sample due to the synergic effect of GO@CS. Among various g-ZnS@GO@CS composites with different GO@CS contents (4, 8, and 12 wt%) the sample containing 4 wt% GO@CS exhibited the highest photoluminescence intensity. The g-ZnS@GO@CS nanocomposite displayed higher antibacterial activity (growth inhibition zone of 27.6 mm) on Gram-positiveStaphylococcus aureusbacteria compared to g-ZnS NPs (growth inhibition zone of 23.5 mm). No significant bioactivity was, however, observed against Gram-negative bacteria (Escherichia coli). According to the results, g-ZnS@GO@CS composite with reduced bandgap, enhanced PL intensity, and smaller ZnS NPs can offer better antibacterial activity as compared to pristine g-ZnS NPs.

关键词： Reconstituted micellar casein   High hydrostatic pressure   Quality follow up  

摘要： The aim of this work was to evaluate the effect of high hydrostatic pressure (HHP) treatments (300 MPa, 450 MPa, and 600 MPa for a holding time of 5 min) on the physicochemical, microbiological and rheological properties of a reconstituted micellar casein concentrate (R-MCC) at two different concentrations (4 and 8% w/w). Quality changes after 7 days at 10 degrees C of treated products were compared to untreated ones. From a microbiological point of view, increased pressures led to a significant reduction of spoilage population. Besides, MCCs treated at either 450 or 600 MPa showed an increase of acidity. Color was also affected by HHP treatments with a loss of lightness and increase of blue/grey tonalities. Reduction of particle size was observed and an aggregation phenomenon was confirmed at 450 MPa and 600 MPa. These results suggest destabilization and disintegration of casein micelles. However, no changes were detected in rheological and multiple light scattering measurements.

关键词： Functional food   Response surface methodology   Overall acceptance   Cape gooseberry  

摘要： The aim of this research was to develop and characterize an innovative nectar formulation of Physalis peruviana fruits from the Argentinean Northern Andean region with optimized proportions of pulp and sucrose that maximizes the antioxidant activity and with good sensorial acceptance, using the response surface methodology as optimization strategy. Physicochemical characteristics (total soluble solids, titratable acidity and pH), antioxidant activity (measured as the free radical scavenging activity against DPPH center dot) and sensorial attributes (color, acidity, sweetness, texture, aroma and overall acceptance) were evaluated in a series of nectar formulations. A significant correlation between overall acceptance and antioxidant activity contributed to achieve the objective outlined. The mathematical modelling defined a nectar with 65% fruit juice and pulp and 8% sucrose;this nectar presented absence of indicator microorganisms (aerobic mesophilic microorganisms, molds and yeasts, Salmonella spp., total coliforms, and Staphylococcus aureus coagulase positive) despite having no added preservatives. beta-carotene and vitamin C contents (1.13 +/- 0.02 and 16.56 +/- 0.52 mg/100 mL respectively) and antioxidant activity towards DPPH center dot (EC50: 2.43 +/- 0.07 mg/mL), ABTS(center dot+) (3.48 +/- 0.07 mu mol Trolox/mL) and FRAP (10.16 +/- 0.10 mu mol Trolox/mL), make this nectar a functional food with potential for the food industry.

关键词： cosmeceuticals   lipid   liquid crystal   retinoids   spectrophotometry   viscosity  

摘要： Introduction Three original cosmetic formulations containing retinol as an active component with liquid crystal, lamellar, and lipid bases were prepared. The formulas contain different concentrations of retinol, that is, 0.5%, 0.3%, and 0.15%. Objectives The aim of the study was to evaluate a spectrophotometric method for assessing the quantity of retinol in the nine cosmetic products and to determine the viscosity of each formula. Materials and Methods The formulations were tested for stability;final product testing was preceded by sample weighing and pH measurement as well as exposure to the light source from xenon lamp that maps solar radiation in the range of 310-800 nm. Microbiological purity test was performed according to the PN-EN ISO 29621:2011 method and viscosity carried out using a cone-plate digital rheometer (DV-III Brookfield, version 3.0) on 0.5 cm(3) emulsion samples at 32 degrees C. The retinol content in preparations was assayed by UV spectrophotometry. Results Each of prepared cosmetic products with retinol storing in a room temperature occurred to be stable. The liquid crystal emulsion has the higher viscosity than lamellar and lipid emulsions. Although the retinol concentration in lipid serum was determined with high accuracy, the method has some limitations associated with differences between the lipid cosmetic base and the lamellar and liquid crystal sera. Nevertheless, the UV spectrophotometric method described herein is a simple and highly accurate approach for determining the retinol content in lipid cosmetics: Its coefficient of correlation was R-2 = 0.9982 with a relative standard deviation (n = 3) in the range of 0.5%-1.5%. Conclusion The presented UV spectrophotometric method represents an effective tool for fast and accurate determination of retinol content in lipid formulations. Probably, the method could be used in studies of other retinol-based preparations, for example, medications, and for determining the effective life of retino

关键词： Gaseous ozone   Buckwheat-wheat-gluten composite flour   Microbial and physicochemical properties   Shelf-life extension of fresh buckwheat noodle  

摘要： In recent years, the application of gaseous or aqueous ozone in the processing of flour and noodles has been reported. However, little information is available about buckwheat-based (buckwheat-wheat-gluten) composite flour treated with gaseous ozone and fresh noodles made from the flour. This study investigated the microbial count, and physicochemical properties of buckwheat-based composite flour treated with gaseous ozone at 2.4 g h(-1) for 0, 2.5, 7.5 and 15 min and the shelf-life of fresh buckwheat noodles made from ozone-treated buckwheat-based composite flour (OTBF). Gaseous ozone significantly (p < 0.05) reduced the microbial total plate count and increased the CIE L* value, water absorption, development time, and stability time of the OTBF. The peak viscosity, final viscosity, setback, swelling capacity and solubility of the flour were also enhanced by ozone treatment. Scanning electron microscopy showed that ozone treatment facilitated the formation of more clumps and exposure of starch granules in the composite flour. In addition, gaseous ozone treatment at 2.4 g h(-1) for 15 min significantly suppressed microbial growth and reduction of L* value, maintained the overall sensory acceptability during the whole storage period, and the shelf-life of fresh noodles prepared from ozone-treated flour was extended to 96 h.

关键词： polyaniline   catalysis   metal phthalocyanines   physical properties  

摘要： The polymerization of aniline in the presence of metal phthalocyanines was accomplished and the effect of the metal complexes on the physicochemical properties of polyaniline was examined based on UV-visible spectra, cyclic voltammograms, morphology and conductivity of the polymers. The formation of polyaniline in the presence of metal phthalocyanines led to an increase in polymer particle sizes and to a slightly higher conductivity of the samples, as compared to those of the initial polyaniline.

关键词： Physicochemical properties  

摘要： Generally, heat-moisture treatment (HMT) modified starch is prepared at atmospheric pressure without stirring, which is time-consuming (8 similar to 24 hr) and uneven heating. The wheat flour (WF) and starch (WS) were modified by HMT in a high pressure reactor with a stirrer. Physicochemical properties of WF and WS after HMT for 30 min with different moisture and temperature conditions were investigated. Compared to native samples, decrease in peak viscosity, and increase in gelatinization temperature were found in both WF and WS after HMT treated at moisture of 25% and 30%. A decrease in rapidly digestible starch and slowly digestible starch content while an increase in resistant starch content was found for all moisture levels. By studying the effect of heat treatment on the digestibility of starch and flour, and the application of heat treatment in noodles, it provides a theoretical basis for the development of staple food products suitable for diabetic patients. Practical applications Resistant starch (RS) within a calorie-controlled diet is thought to be beneficial in protecting against metabolic syndrome and colon cancer. With the acceleration of the pace of life, a diet high in sugar and fat and a sedentary lifestyle, which can led to a rapid rise in the global incidence of diabetes. Therefore, reasonable diet is significant to stabilize and improve the condition of diabetic patients. Wheat flour provides the basis for breads and other baked products including noodles. Noodles are one of China's traditional staple foods. It is of great importance to explore and develop the noodle recipe suitable for the diabetic diet. Heat moisture treatment is an important physical treatment method used to improve the poor functional properties of native starch and is specially favorable for food applications. In this study, RS of wheat flour and starch was significantly increased during heat-moisture treatment. By studying the effect of heat treatment on the digestibility o

关键词： Bio-oil   Heavy fraction   Pyrolysis   Heating rates   Evolution  

摘要： The effects of heating rate on the evolution of tar obtained from heavy fraction of bio-oil (HB) were revealed by the change of elements, functional groups and chemical compounds. The results showed that slow heating rate had a negligible effect on the physicochemical properties of HB from 400 to 800 degrees C. By contrast, decomposition, radical recombination and polymerization reactions could occur at fast heating rate. A clear trend of increasing tar yields was monitored from 300 - 500 degrees C. However, a significant decrease was observed at high temperature (600 - 800 degrees C). Through elemental analyzer, C content in tar expanded with the temperature increasing, whereas N content remained unchanged. Nuclear magnetic resonance (NMR) spectroscopy results indicated that the carboxyl functional groups would be destroyed at high temperature. Furthermore, the concentrations of aromatics showed a trend to increase accompanied by a simultaneous decrease in phenols with the temperature rising according to gas chromatography/mass spectrometer (GC/MS) analysis.

关键词： Bi2WO6   CeO2   Iron doping   Nanocomposite   Photocatalytic activity   Wastewater treatment  

摘要： Fe-doped Bi2WO6/CeO(2)nanocomposite materials were prepared by co-precipitation and hydrothermal methods. The physicochemical properties and photocatalytic activities of Bi2WO6/CeO(2)nanocomposites after doping with Fe(3+)ions were systematically investigated. The 0.2Fe-doped Bi2WO6/CeO(2)nanocomposites exhibited the optimal photocatalytic activity in the degradation of rhodamine B (RhB), reaching to 62% degradation after 120 min irradiation, which was 10.3 and 2.7 times higher than CeO(2)and Bi2WO6, respectively. The improved photocatalytic activity was mainly ascribed to the enhanced charge carrier separation efficiency of the direct Z-scheme heterojunction system. Moreover, the effective trapping of photogenerated electrons and holes by iron ions inhibits the electron-hole recombination. By a trapping experiment, the main radicals (O-2(center dot-)) in the photocatalysis experiment were further ascertained. Finally, we proposed the photocatalytic mechanism of Fe-doped Bi2WO6/CeO(2)nanocomposite for RhB degradation.

关键词： chromite rocks   chromium oxide   enrichment   filler   refractory material  

摘要： The mineral and chemical compositions of the chromite raw materials of the Karelia-Kola region are studied, and physical and chemical processes for producing refractory materials from chromite concentrate are established. The phases and structure formed during drying, firing, and service are determined. The dependence of some refractory properties on their material, grain, and phase compositions is established.