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关键词： Wheat starch   WS-LA complexes   Moist-heat   Dry-heat   Microstructure   In vitro digestibility  

摘要： Herein, we investigated the impact of moist (steaming and boiling) and dry (baking and microwaving)-heat treatment processes on the structure and physicochemical properties of wheat starch (WS) supplemented with lauric acid (LA). Elemental composition analysis revealed the interplay between WS and LA. Scanning electron microscopy (SEM) and iodine staining revealed that lamellar crystalline structure of WS-LA complexes was improved after moist-heat treatment (relative to samples without any heat treatments);the finding which is at variance to dry-heat treatment process. Additionally, high resistance to thermal decomposition and a lower 1022/995 cm-1 absorbance ratio were observed in moist-heat treated WS-LA compared with dry-heat samples. Moreover, the V-type diffraction peak intensity and resistance to in vitro enzymatic hydrolysis of samples treated with moist-heat were increased to a greater extent than the dry-heat treated counterparts. In sum, this study would facilitate the application of functional starch-lipid complexes in food necessitated heat treatments.

关键词： Shrimp   Myofibrillar protein gel   Oxidation   Microstructure   Water distribution   Mechanical properties  

摘要： Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but beta-sheet increased after oxidation. The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51-and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.

关键词： alternatives to animal testing   in silico predictions   QSAR   QSARINS   virtual screening  

摘要： The new software QSARINS-Chem standalone version is a multiplatform tool, freely downloadable, for the in silico profiling of multiple properties and activities of organic chemicals. This software, which is based on the concept of the QSARINS-chem module embedded in the QSARINS software, has been fully redesigned and redeveloped in the Java (TM) language. In addition to a selection of models included in the old module, the new software predicts biotransformation rates and aquatic toxicities of pharmaceuticals and personal care products in multiple organisms, and offers a suite of tools for the analysis of predictions. Furthermore, a comprehensive and transparent database of molecular structures is provided. The new QSARINS-Chem standalone version is an informative and solid tool, which is useful to support the assessment of the potential hazard and risks related to organic chemicals and is dedicated to users which are interested in the application of QSARs to generate reliable predictions.

关键词： Doubanjiang   Flavor   Microbial dynamics   Physicochemical parameter   Salt concentration  

摘要： This study aimed to elaborate the roles of salt concentration on doubanjiang (broad bean paste) fermentation. Three sets of doubanjiang samples which had lower salt concentration than commercial doubanjiang were prepared and the physicochemical parameters, biogenic amines, flavor, microbial dynamics were analyzed during fermentation. The salt reduction showed significant effect on the dynamics of bacteria and fungi, thus leading to doubanjiang samples with different properties. Salt reduction during fermentation relieved the osmotic pressure towards microbes, which favored the accumulation of amino acid nitrogen, amino acids, and volatile flavor compounds. However, higher concentrations of total acids and biogenic amines and the existence of conditional pathogens, such as Klebsiella, Cronobacter and Acinetobacter genera, were observed in salt reduced doubanjiang samples, which was undesirable for doubanjiang quality. This study would deep our understanding of the roles of salt on doubanjiang fermentation.

关键词： cerium dioxide nanoparticles   synthesis   chemical state   morphology   catalase   peroxidase activity   zeta-potential  

摘要： A set of cerium dioxide nanoparticles (CeO(2 )NPs) was synthesized by precipitation in water-alcohol solutions under conditions when the physical-chemical parameters of synthesized NPs were controlled by changing the ratio of the reaction components. The size of CeO2 NPs is controlled largely by the dielectric constant of the reaction solution. An increase of the percentage of Ce3+ ions at the surface was observed with a concomitant reduction of the NP sizes. All synthesized CeO2 NPs possess relatively high positive values of zeta-potential (zeta > 40 mV) suggesting good stability in aqueous suspensions. Analysis of the valence- and size-dependent rate of hydrogen peroxide decomposition revealed that catalase/peroxidase-like activity of CeO2 NPs is higher at a low percentage of Ce3+ at the NP surface. In contrast, smaller CeO2 NPs with a higher percentage of Ce3+ at the NP surface display a higher oxidase-like activity.

关键词： Activation energy  

摘要： In this study, Na4SnS4 and Na4SnSe4 compounds were successfully synthesized and their physicochemical performances were systematically investigated via experimental and theoretical methods. Research results show that they display excellent properties as potential infrared nonlinear optical (IR NLO) crystals and sodium ion conductors, including large NLO effects (0.7 vs. 1.8 x benchmark AgGaS2), high laser-damage resistance (9.0 vs. 3.5 x AgGaS2), moderate ion conductivities and small activation energies. Moreover, their structure-performance relationship was also studied via first principles calculations.

关键词： Antioxidant   Colour   Harvest stage   Jackfruit   Sugars   Pollination  

摘要： Pollination techniques could affect fruit size, whereas optimal maturity stage during harvest could affect postharvest life and the eating quality of fruit. Therefore, the right pollination technique and timing to harvest fruit is an important factor in reducing postharvest losses. The objective of this study was to determine the physicochemical changes of jackfruit harvested at four different maturity stages and produced from natural and assisted pollination. This study was conducted at a jackfruit commercial farm in Bukit Beruntung, Selangor, Malaysisa. For assisted pollination, the selected female inflorescences were covered with bags before anthesis. Hand pollination was performed by gently rubbing mature male inflorescences over the surface of receptive female inflorescences. For natural pollination, female inflorescences were left to develop into syncarps by themselves. Syncarps at the age of 12, 13, 14 and 15 weeks after anthesis (WAA) were used in this study. For each maturity stage, four syncarps were harvested and allowed to ripen naturally at 27 +/- 2 degrees C and 70-80% relative humidity until a sweet aroma was detected. Physico-chemical characteristics such as colour, firmness, pH, titratable acidity, beta-carotene, lycopene content, sugars, organic acid content and antioxidant activity were evaluated. In this study, the pollination technique did not affect the eating quality of jackfruit flesh. However, the physico-chemical quality of jackfruit flesh was affected by ripening level and WAA. The initial stages of syncarp maturity, the L*, C* and h(o) values, remained unaffected. However, the L*, C* and h(o) decreased significantly from 14 WAA onwards when the syncarp rind turned fully yellow. This indicated that the rind and bulb colour became lighter and less intense with a green colour changing to yellow during ripening. Rind and flesh firmness decreased as ripening progressed due to cell wall modification and starch hydrolysis when ripening occurred.

关键词： physicochemical property   in situ gastric perfusion   in situ single-pass intestinal perfusion   pharmacokinetics  

摘要： The orally available novel small molecule drug ZWF is under preclinical development for an anticancer purpose. The present study aimed to assess the viability of developing ZWF as a form of oral formulation for clinical application based on the principles of biopharmaceutics and pharmacokinetics. The crucial physicochemical properties of ZWF were determined by in vitro assays. The in situ gastrointestinal absorption characteristics and in vivo pharmacokinetic behaviors of ZWF in rats were characterized. The solubility of ZWF showed a highly pH-dependent profile, decreasing from 25,392.89 to 20.48 mu g/mL as the solution pH increased from 1.0 to 5.8. In PBS with a pH of 1.0 to 5.8, the LogP value of ZWF ranged from -2.35 to 2.20 and was gradually increased as the pH value increased. ZWF was partially absorbed in the stomach, and the favorable absorption sites were the duodenum, jejunum, and ileum. Pharmacokinetic studies showed that the AUC((0-t)) and C-max values of ZWF after its oral administration as a suspension prepared with 0.5% CMC-Na were increased by 18.97% and 40% than that with normal saline, providing a model oral formulation of ZWF with ideal bioavailability and system exposure in rats. From the perspective of oral absorption, ZWF possessed appealing qualities as a drug candidate and could be prepared as an oral preparation for clinical application. The present study has established a fundamental foundation for the development and quality evaluation of the ZWF oral formulations.

关键词： Thin films  

摘要： Due to their outstanding physical and mechanical features, ZrN thin films are increasingly used as coatings to protect materials intended for nuclear applications such as Zirconium. To our knowledge, there is no report of pulsed laser deposition (PLD) of ZrN thin films on a Zr substrate. In this work, we have successfully prepared ZrN thin films on Zr substrates using the PLD technique with a KrF excimer laser, in a N-2 environment at 2 Pa pressure and a fixed substrate temperature of 500 degrees C. The deposited 200 nm ZrN thin films exhibited a homogeneous surface and showed a face-centered cubic polycrystalline structure. The surface roughness was 3.69 nm. X-ray diffraction, Raman and X-ray photoelectron spectroscopy measurements confirmed the presence of ZrN. The coated sample's mean value of hardness (11.6 GP) doubled that of the uncoated sample.

关键词： Magnetic moments  

摘要： We have studied, using DFT calculations, some geometrical and electronic properties of delaminated pyrophyllite (D-P) and the corresponding layers that result from three isomorphic substitutions on octahedral sheets (Mg2+, Fe2+ and Fe3+). Bond lengths, layer thickness (d(L)), band gap (E-g), work function (WF), magnetic moment (mu), density of states and charge distributions are reported. These properties are important to control the behaviour of electronic devices. The results show that the layer thickness increases according to the ionic radius of the considered substituent. In the case of the three substitutions a reduction of the forbidden band is observed. Mg2+ induces a decrease in the E-g value of about 16.5% with respect to D-P, whereas for Fe this reduction is more significant due to the presence of trap states in the forbidden zone. For Fe2+ (Fe3+) the reduction in the E-g is around 62% (51%). Regarding the WF, our results showed that there is a decrease in its value after substitution. D-P has the highest WF value (8.15 eV), whereas the delaminated clay with Fe2+ has the lowest value (2.22 eV). Finally, D-P and D-P substituted with Mg2+ have a diamagnetic behaviour (mu = 0), whereas the presence of Fe2+ and Fe3+ induces a paramagnetic behaviour. The computed magnetic moment is 4 mu(B) and 1 mu(B) for D-P substituted with Fe2+ and Fe3+, respectively.