教学课程资源库 更多>>

关键词： dietary fiber   potato starch   viscosity   retrogradation   thermal analysis   fruit mousse  

摘要： BACKGROUND Fruit mousses are products with a relatively low amount of dietary fiber in a single portion, but with additional portions of soluble fiber they may be good alternative to fiber-rich snacks as take-away food. In the present study, the properties of new soluble dextrin fiber (SDexF) from potato starch were assessed to establish whether it could be used to enrich fruit mousses. The properties of SDexF that can affect processing and storage stability of enriched mousses were studied and compared with those of native potato starch and semiproducts (resulting from various drying temperatures). The effect of the addition of SDexF on the pasting properties of mousse was also analyzed. RESULTS The application of food-grade hydrochloric and citric acids as catalysts in the dextrinization of food-grade potato starch allowed to SDexF to be obtained. Despite the differences in characteristics of the semiproducts, the final SDexF preparations were very similar in the meaning of solubility, dextrose equivalent (DE), retrogradation, and pasting properties. SDexF preparations were characterized by a significantly lower retrogradation tendency, peak viscosity, final viscosity, and gelatinization enthalpy in comparison with both native starch and semiproducts. Soluble dextrin fiber was successfully added to banana-apple mousse. The addition of SDexF to mousse did not cause any undesirable changes to the viscosity of the product, and surprisingly even resulted in mousse with lower viscosity. Turbidity and RVA studies revealed that SDexF was stable and retrogradation processes can be negligible during storage. CONCLUSION The SDexF obtained from potato starch can be a novel functional substance to increase the dietary fiber content of fruit or fruit and vegetable mousses. (c) 2020 Society of Chemical Industry

关键词： Metabolic profiles   Amino acid secretion   Soil cadmium availability   Paddy soil   Soil pe plus pH variation  

摘要： Periodic flooding in paddy soils impacts redox behavior and induces variations in pe+pH levels. Manganese (Mn) is capable of reducing cadmium (Cd) uptake by rice. However, the processes involved in how Mn alters Cd mobilization under different pe+pH environments remain poorly understood. To investigate the mechanisms of Mn-mediated soil Cd-stabilization and subsequent inhibition of Cd uptake from flooded soils, we examined Cd immobilization in soil pot incubations, transcriptional changes in Cd-transport genes, and metabolomic analyses of roots and rhizosphere soils with or without Mn application. We found a decrease in extractable Cd concentration largely depended on irrigation-associated low pe+pH, exogenous Mn enhancement of Fe-Mn (oxyhydro) oxide-mediated Cd transformation, and Cd deposition in rice Fe/Mn plaques. Mn application led to striking effects on the expression of Cd-related genes eg. IRT, HMA, and NRAMP in rice root tissue. Exposure to Mn under variable pe+pH levels resulted in metabolic reprogramming of soil and rice roots. Mn induced amino acid synthesis in rice roots, leading to rhizosphere accumulation of free L-lysine, glycine, and glutamine, which can reportedly bind metal ions, forming complexes with Cd. Thus, secreted amino acids, low pe+pH, and free Mn can together comprise a multi-faceted approach to managing Cd toxicity in rice.

关键词： Nutrition   Organic compounds   Solution chemistry   Electrical conductivity   Surfactants  

摘要： Studies on the interactions of surfactant molecules with water-soluble vitamins have significance in pharmaceutical, biological, and industrial processes. Their mixed micelles can be used as a model for understanding the complex behavior encountered in food and biological assemblies. In this context, self-assembling properties of hexadecyltrimethylammonium bromide, HTAB, and sodium cholate, NaC, and their mixtures at molar fractions, alpha(HTAB) = (0.02, 0.04, and 0.13), have been investigated in water as well as in (1, 2, and 3) x 10(-4) ***(-1) pyridoxine HCl(aq) (vitamin B-6) solutions by employing various techniques. Critical micelle concentration, degree of ionization (g), and standard thermodynamic entities (Delta G(m)(0), Delta H-m(0), and Delta S-m(0)) of micellization which state the physicochemical properties of the studied system have been determined from the conductivity measurements at 298.15, 308.15, and 318.15 K. The partial specific volume (phi(v)), isentropic compressibility (kappa(s)), and partial specific isentropic compressibility (phi(kappa)) were evaluated using the density and sound velocity data. UV-visible absorption and fluorescence emission spectra were recorded for pyridoxine HCl( aq) solutions in the presence of HTAB and NaC and mixed (HTAB + NaC) surfactants at alpha(HTAB) = (0.02, 0.04, and 0.13) and at T = 298.15 K. Through dynamic light scattering studies, the hydrodynamic diameters (D-h) of aggregates have been examined.

关键词： X-ray absorption near edge spectroscopy   Oxidation state   Extended X-ray absorption fine structure   Oxygen   Perovskites  

摘要： A novel combined chemical procedure was employed to synthesize a homogeneous SrMo0.9Co0.1O3-delta (SMC) perovskite at lower temperatures (900 degrees C). The physicochemical properties of SMC were analyzed by means of in situ X-ray diffraction and X-ray absorption spectroscopy experiments under reducing and oxidizing conditions from 20 to 700 degrees C. The study revealed a strong interaction between Mo and Co cations in the SMC perovskite, which led to their unexpected oxidation number speciation and a critical modification of their first coordination shell. Perovskite-like unit cells containing Co in their center can drastically increase the occupation number of oxygen anions, enhancing SMC oxygen storage capability. Under reducing conditions, these loosely bonded anions were easily released from the material to chemically react with H-2 in the gas phase. These findings bring novel insights into the physicochemical processes that take place in SMC materials and give rise to the catalytic and electrochemical activity that makes this material a candidate for intermediate temperature-SOFC anode application.

关键词： solid oxide fuel cell (SOFC)   physical vapor deposition (PVD)   Gd-doped ceria (CGO)   ESC   zirconate   residual stress  

摘要： To minimize alteration of the La0.6Sr0.4Co0.2Fe0.8O3-delta(LSCF)/Gd0.2Ce0.8O2-delta(CGO20)/Y0.06Zr0.94O2-delta(3YSZ) interface via strontium zirconate formation in solid oxide cells, electron beam physical vapor deposition was employed to manufacture dense, thin gadolinium-doped ceria (CGO) interlayers. CGO layers with thicknesses of 0.15, 0.3, and 0.5 mu m were integrated in state-of-the-art 5 x 5 cm(2)-large electrolyte-supported cells, and their performance characteristics and degradation behavior were investigated. Electrochemical impedance spectroscopy measurements are correlated with a postmortem scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis to show that 0.15 mu m thick layers lead to the formation of a continuous Sr-containing secondary phase at the CGO/YSZ interface, likely related to the formation of a SrO-ZrO2 phase. Major performance losses were confirmed by an increase in both Ohmic and polarization resistance with an increase in the frequency region similar to 10(3) Hz. Cells with 0.3 mu m- and 0.5 mu m-thick CGO layers showed similar high performance and low degradation rates over a testing period of similar to 800 h. The YSZ/CGO interface of the cells with a 0.3 mu m-thick CGO layer showed the formation of a discontinuous Sr-containing secondary phase;however, performance losses were still successfully prevented. Furthermore, it is observed that 0.5 mu m-thick CGO layers were sufficient to suppress the formation of the Sr-containing secondary phase.

关键词： Tramadol   Abuse-deterrent index   Abuse deterring agents   Particle size   Swellability   Dissolution rate   Solvent extraction  

摘要： In the design of abuse-deterrent formulations (ADFs), pharmaceutical strategies that do not modify the physical and chemical properties of opioid dosage forms should be investigated. Among these, four major drug abusing factors, including particle size by physical modification, swellability, dissolution rate, and solvent extraction, were mainly characterized for evaluating abuse deterrence of narcotics. Tramadol hydrochloride (TMD) was chosen as a model drug. In this study, the frequently used eight generally recognized as safe (GRAS)-listed pharmaceutical excipients, including polyvinyl alcohol (PVA), hydroxypropyl methylcellulose (HPMC 4,000, HPMC 100,000), xanthan gum (XG), cellulose acetate (CA), polyethylene oxide (PEO), carbomer 940 NF, and Compritol (R) 888 ATO, were selected as abuse deterring agents and used to prepare TMD-loaded tablet. A new abuse-deterrent index (ADI) for compressed TMD-loaded tablets was originally defined and considered as an index of drug abuse deterrence, based on the assumption that it was proportional to particle size and swellability but inversely proportional to dissolution and solvent extraction rates after assigning the categorized five scale scores (one to five) to the four experimental data. The resulting ADI of the selected eight abuse deterring agents in deionized water was given in decreasing order: HPMC 4000 > carbomer 940 > Compritol (R) 888 ATO > XG > PVA > HPMC 100,000 > PEO, and CA while in 40% hydro-alcoholic solution in the decreasing order: carbomer 940 > HPMC 4,000 approximately equal to or the image of XG > PVA > HPMC 100,000 > PEO > Compritol (R) 888 ATO > CA. Interestingly, the HPMC 4,000 and carbomer 940 showed the highest ADI and gave drug abuse deterrent potential. This study could provide a pharmaceutical strategy that utilizes a variety of abuse-deterring agents and resist to extraction solvents in designing drug abuse-deterrent formulations and establishing their standard guidelines for regulatory authori

关键词： Fermentation  

摘要： The aim of this study was to evaluate the physicochemical properties and aroma differences of yellow pea flours fermented by five lactic acid bacteria (LAB) strains including two Lactiplantibacillus, two Lactobacillus, and one Lacticaseibacillus with different fermentation time. The cell population and the pH of pea flour slurry, as well as the proximate chemical composition, amino acids, thermal and pasting properties, surface morphology, and aromatic differences of fermented flours were characterized. The cell population of all strains except for Lactobacillus helveticus was observed to reach above 10(7) CFU mL(-1) after 24 h of fermentation. The fermentation with Lactobacilli resulted in the increase of amino acids and ash contents, and the reduction of fat content. Rapid viscosity analysis indicated that short time (18 h) fermentation with L. helveticus drastically improved the pasting properties of the flours by facilitating starch granule expansion. The aromatic compounds of the fermented yellow pea flours were highly reliant on the strains and fermentation time. The untargeted metabolomics analysis with the aid of multivariate data analysis can discriminate the aroma differences among the fermented yellow pea flours. L. acidophilus fermentation led to the production of three aromatic compounds which may contribute to an improved aromatic profile.

关键词： DFT   Mixed-valence complex   Vibrational frequencies   HOMO-LUMO   NLO   Thermodynamic functions   Magnetic properties  

摘要： The bidentate amine, 2-picolylamine [2-(aminomethyl) pyridine: AMP], and concentrated hydrobromic acid have been used to synthesize a Co-II/Co-III mixed-valence complex. Single crystals of the new compound were grown by the slow evaporation solution process at room temperature. The title compound crystallizes in the monoclinic system, space group P2(1)/n, with a = 14.624 (5) angstrom, b = 10.302 (5) angstrom c = 23.743(5) angstrom, beta = 95.280(5)degrees and Z = 4. The crystal structure consists of three crystallographically independent bromide ions, one diprotonated AMP, one half water molecule and two crystallographically independent Cobalt(II) an d Cobalt(III) ions: one has an octahedral geometry while the other is tetrahedrally coordinated. The crystal packing diagram reveals interesting non-covalent interactions involving N-H center dot center dot center dot Br, O-H center dot center dot center dot O and O-H center dot center dot center dot Br hydrogen bonds, leading to the generation of 3D supramolecular architecture. The structural data, the BVS (Bond Valence Sum) calculations, the magnetic and the spectroscopic measurements are in agreement with a six-coordinate Cobalt(III) and four-coordinate Cobalt(II) mixed-valence complex. In this work, the experimental and theoretical study on molecular structure and vibrational spectral analysis of the new product has been reported. Theoretical calculations were performed by using density functional theory (DFT) at the B3LYP/LAN2DZ basis set levels. The electronic parameters such as frontier molecular orbitals, electrostatic potential and HOMO-LUMO energy were calculated. NLO and thermodynamic properties were studied. The theoretical values show good agreement with experimental values. Finally, thermal analysis and temperature dependent magnetic susceptibility measurements have been performed. (C) 2021ElsevierB.V. All rights reserved.

关键词： Adsorption   Dissolution   Coal   Functional groups   Minerals  

摘要： Regarding CO2 geologic sequestration in the coal seam, injected CO2 in the coal reservoir at an optimum depth often presents as supercritical fluid (scCO(2)), which is capable of changing the physicochemical properties of coal and further affecting its CO2 storage capacity. Aiming to better explore the aforementioned influences, we conducted a long-term scCO(2)-H2O-coal static interaction in the laboratory. The influences of scCO(2) exposure on the pore structure characteristics, the main oxygenic functional groups, and the high-pressure CO2 adsorption and desorption capabilities of four rank coals were explored. The results show that long-term scCO(2)-H2O exposure has minor effects on the coal micropore surface area and volume. On the contrary, it remarkably decreases the mesopore of all of the coals. The alterations in the coal pore structure parameters are mainly relevant to coal matrix swelling and mineral dissolution due to long-term scCO(2)-H2O exposure. In general, long-term scCO(2)-H2O exposure increases the Neimark fractal dimension of coals, further implying an elevated pore surface roughness and a more complex pore structure. Moreover, the main oxygenic functional groups, including C-O, C=O, and -COOH, of coals after long-term scCO(2) exposure are reduced. The aforementioned changes in the physicochemical properties of coals further affect their CO2 adsorption and desorption capabilities. In particular, the maximum CO2 adsorption capacity of high-rank coals decreases after exposure, whereas that of low-rank coals increases. Furthermore, the CO2 adsorption and desorption hystereses of coals become pronounced after long-term scCO(2)-H2O exposure, implying more stable CO2 sequestration in the coal seam. In conclusion, the implementation of CO2 sequestration in the coal seam should focus on the long-term scCO(2)-H2O-coal interaction.

关键词： Crystal structure   Oligomers   Molecules   Noncovalent interactions   Solubility  

摘要： Five cocrystals of antiviral drug favipiravir (Fav) with respiratory drug theophylline (Theo) and GRAS coformers, viz., p-aminobenzoic acid (PABA), 4-hydroxybenzoic acid (4HBA), gallic acid (GA), and ferulic acid (FRA), were successfully synthesized using mechanochemistry as well as solution crystallization. All the synthesized cocrystals were characterized using PXRD, SCXRD, and thermal analysis. A physicochemical property investigation showed an excellent correlation of coformer solubility with cocrystal solubility. Moreover, cocrystal solubility can be tuned based on the selection of coformers during cocrystallization as well as the pH of the medium. Crystal structure analysis depicts amide-amide homosynthon formation in the *** cocrystal and an acidamide heterosynthon in the case of cocrystals with GRAS coformers. Incorporation of nutraceuticals (GA and FRA) provides an additional health benefit, whereas *** cocrystal may be a potential formulation to treat patients suffering from chronic obstructive pulmonary disease (COPD) or asthma along with viral infections.