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关键词： Physicochemical properties  

摘要： Fettuccine-type pasta was made from wheat semolina mixed with 5%, 10%, 15%, 20%, and 25% of huitlacoche mushroom powder (HMUP), and the effect on quality, physicochemical, antioxidant capacity, and color properties was studied. Proximate analysis studies on the pasta showed that a higher content of HMUP in the mixture increases lipids, fiber, and ash levels, without affecting protein content. Cooking time in the pasta decreased with increasing HMUP. Quality parameters as cooking loss, cooking weight gained, solubility index, and swelling were influenced by increased HMUP in the pasta. Luminosity (L*) values decreased drastically as HMUP increased. Cooking also influenced color parameters (Delta L* and Delta C*), Antioxidant capacity (DPPH, ABTS, FRAP) and total phenols increased with higher HMUP concentrations in raw and cooked pasta. These results suggest that HMUP could be incorporated into semolina flour to prepare fettuccine-type pasta, conferring healthy characteristics due to the preservation of antioxidant capacity after cooking. Novelty impact statement Huitlacoche powder concentration (5% to 25%) does not affect the quality properties of the pasta. Furthermore, increase of this concentration, caused a higher antioxidant activity, and a preservation of this activity by up to 40% even after the cooking process.

关键词： Chalcone derivatives   Molecular hyperpolarizability   Thermal analysis   Z - Scan study  

摘要： Optically highly versatile novel third-order organic nonlinear single crystals of (2E)-1-(3,4-dimethoxyphenyl)-3-(4propoxyphenyl)prop-2-en-1-one (DMPP) which adapts to orthorhombic Pbca space group is crystallized by slow evaporation growth technique. Fourier transform infrared analysis affirms the presence of various functional groups in DMPP. Transparency and lower cut-off wavelength of the crystal were obtained using linear optical properties. The thermal stability without any weight loss is up to 220 degrees C. The molecular structure of DMPP was confirmed by H-1 NMR and C-13 NMR analysis. From the electrical conductivity studies, the suitability of DMPP chalcone for device fabrication with a very low activation energy value of 0.04 at 1 MHz and conductivity value of 10(-4) S/m was observed for the first time. Further B3LYP/6-31G++ level has been used to obtain static first-order and second order hyperpolarizability parameters. The calculated value of first-order hyperpolarizability was calculated to be 96 times better than that of standard urea and several orders better compared to other 3,4 dimethoxy derivatives. The experimental third order nonlinear measurements were done by continuous-wave (cw) 632.8 nm laser. From the Z-scan measurements, the calculated imaginary and real third-order nonlinear optical susceptibility are of the order of 10(-5) e.s.u. The experimental and computational results disclose that DMPP is a novel third-order optically active single crystal and a noteworthy material for nonlinear optical applications.

关键词： Adsorption of spike protein   Charge distribution over spike protein   Receptor attachment of spike protein   SARS-CoV-2 virion   Spike protein   Structure of SARS-CoV-2 virion  

摘要： The structure, size, and main physicochemical characteristics of the SARS-CoV-2 virion with the spike transmembrane protein corona were discussed. Using these data, diffusion coefficients of the virion in aqueous media and in air were calculated. The structure and dimensions of the spike protein derived from molecular dynamic modeling and thorough cryoelectron microscopy measurements were also analyzed. The charge distribution over the molecule was calculated and shown to be largely heterogeneous. Although the stalk part is negatively charged, the top part of the spike molecule, especially the receptor binding domain, remains positively charged for a broad range of pH. It is underlined that such a charge distribution promotes the spike corona stability and enhances the virion attachment to receptors and surfaces, mostly negatively charged. The review is completed by the analysis of experimental data pertinent to the spike protein adsorption at abiotic surfaces comprising nanoparticle carrier particles. It is argued that these theoretical and experimental data can be used for developing quantitative models of virus attachment to surfaces, facilitating adequate analysis of future experimental results.

关键词： Therapeutic cell encapsulation   droplet formation   electrostatic generator   modeling   high-speed camera  

摘要： Cell-encapsulation is used for preventing therapeutic cells from being rejected by the host. The technology to encapsulate cells in immunoprotective biomaterials, such as alginate, commonly involves application of an electrostatic droplet generator for reproducible manufacturing droplets of similar size and with similar surface properties. As many factors influencing droplet formation are still unknown, we investigated the impact of several parameters and fitted them to equations to make procedures more reproducible and allow optimal control of capsule size and properties. We demonstrate that droplet size is dependent on an interplay between the critical electric potential (U-c,), the needle size, and the distance between the needle and the gelation bath, and that it can be predicted with the equations proposed. The droplet formation was meticulously studied and followed by a high-speed camera. The X-ray photoelectron analysis demonstrated optimal gelation and substitution of sodium with calcium on alginate surfaces while the atomic force microscopy analysis demonstrated a low but considerable variation in surface roughness and low surface stiffness. Our study shows the importance of documenting critical parameters to guarantee reproducible manufacturing of beads with constant and adequate size and preventing batch-to-batch variations.

关键词： Achira   Starch characterization   Structural properties   Thermal properties   Pasting properties   Canna edulis  

摘要： Four Colombian achira (Canna edulis sp.) starch ecotypes were characterised, and their physicochemical, thermal, microstructural and paste properties were compared. Proximate composition, pH, total starch, amylose content, amylopectin content, colour, paste clarity, water retention properties, granule size, crystal structure, and thermal and pasting properties were evaluated. Moisture content, protein content, water absorption and swelling power were greatest (P < 0.05) for "Negra" and "Morada" but "Negra"had more lipid and higher solubility (P 0.05). The brightest (L* 92) ecotypes ("Nativa" and "Morada"), in addition to ecotype "Negra", had superior paste clarity compared with ecotype "Verde". All four ecotypes presented a B-type X-ray pattern and large grain size (>30 mu m);only "Morada" presented 40.30% medium-sized-grains. Ecotypes "Nativa" and "Negra" showed the greatest thermal transition temperature, whereas, ecotypes "Verde" and "Morada" had the highest peak viscosity. Each ecotype showed unique properties and specific behaviour that are worth exploring in various applications.

关键词： Mercury   Tibetan Plateau   Glacier   Snow   Laohugou Glacier No   12   Qilian Mountain  

摘要： In this work, samples of surface snow, surface ice, snow pit and meltwater from the Laohugou Glacier No. 12 on the northern edge of Tibetan Plateau (TP) were collected during the summer of 2015. The average concentration of Hg in surface snow/ice was 22.41 ng L-1, while the percentage of dissolved mercury (Hg-D) was observed to be around 26%. An altitudinal magnification of Hg was not observed for surface snow;however, in contrast, a significant positive magnification of Hg with altitude was observed in the surface ice. A higher concentration of Hg corresponded with the dust layer of the snow pit. It was observed that about 42% of Hg was lost from the surface snow when the glacier was exposed to sunlight within the first 24 h indicating some Hg was emitted back to the atmosphere while some were percolated downwards. The result from the principal component analysis (PCA) showed that the sources of Hg in Laohugou Glacier No. 12 were from crustal and biomass burning. Finally, it was estimated that total export of Hg from the outlet river of Laohugou glacier No. 12 in the year 2015 was about 1439.46 g yr(-1) with yield of 22.77 mu g m(2) yr(-1). This study provides valuable insights for understanding the behavior of Hg in the glacier of the northern Tibetan Plateau.

关键词： dietary fibre   digesta   doughballs   lactic acid   pigs   rye   stomach  

摘要： Despite quite similar contents of starch and crude fibre of wheat and rye, the unique non-starch-polysaccharide fraction of rye (e.g. high levels of arabinoxylans and fructans) might have an impact on physicochemical properties of the digesta in pigs. Forty pigs (age: 46.8 +/- 5.28 days;bodyweight: 16.1 +/- 4.13 kg) were divided into four treatment groups. During four weeks, the pigs received diets consisting of wheat and/or rye, barley, soy, potato protein and a mineral supplement. The sum of wheat and rye was 69% in all diets, whereby the compound feed of each group was characterized by a different ratio (%) of wheat/rye (69/0;46/23;23/46;0/69, respectively). In the stomach, 'doughballs' occurred more frequently with increasing dietary rye levels (9/10;69% rye). With higher DM content and extract-viscosity of gastric digesta, the stomach emptying tended to be retarded in rye groups. Compared to the control group (69% wheat), maximum dietary rye levels (69%) resulted in significantly higher concentrations of lactic acid in digesta of the stomach and small intestine. With increasing lactic acid concentrations, the pH tended to be lower in small intestinal digesta. With an intensified formation of lactic acid, effects against Gram-negative bacteria, for example Salmonella, can be expected. Moreover, because of higher viscosity and the retarded stomach emptying, there could be advantages of including rye in compound feeds when a longer lasting satiety is intended, for example when feeding pregnant sows (regularly fed restrictively).

关键词： Geochemistry   Holocene   Mineralogy   Organic Matter   South-Eastern Tunisia  

摘要： The characterization of organic matter (OM) composition, physico-chemical, geochemical, and mineralogical studies of sedimentary core can help to better understand the paleoclimates and the depositional environments. The purpose of this work is to identify the factors monitoring the mineralogical composition and the sedimentation of sebkha Mhabeul sediments (southeastern Tunisia), during the Holocene. A 100.5 cm core (Mh 1) collected from this sebkha was analyzed for the determination of chemical composition by X-ray fluorescence (XRF), carbonate content by Bernard calcimetry, grain-sized sediments by AFNOR sieves, OM content by Rock-Eval 6 Pyrolysis, and mineralogical composition by X-ray diffraction (XRD), scanning electronic microscope (SEM), and infrared spectroscopy (IR). The sedimentary fillings of this sebkha, constituted by fine fractions, are characterized by the dominance of the detrital minerals (72–96 %) with high quartz percentages (42.2–91.5 %). The mineralogical composition of the studied sediments included detrital minerals (clay minerals, quartz, and feldspars), carbonate minerals (ankerite, dolomite, and calcite), and evaporitic minerals (halite, bassanite). The clay minerals (11–14%) are composed of a mixture of kaolinite, illite and palygorskite. Fourier transform infrared (FTIR) absorption spectra of all sediment samples confirm the mineralogical composition obtained by XRD and the existence of OM, by defining the band assignments for OM and different minerals as quartz, feldspar, clay, and carbonate minerals. The Rock Eval pyrolysis shows that the OM is immature and has a mixed origin (terrestrial and aquatic). The statistical analyses prove the results of geochemical and mineralogical studies. Indeed, the principal component analysis (PCA) of geochemical and mineralogical data and the depth help to prove the relationships between minerals and chemical elements. Moreover, the negative correlation between the Rock Eval Pyrolysis parameters and t

关键词： Antioxidant capacity   Avocado   fatty acids   phenolic compounds   phytosterols   tocopherols  

摘要： This work aimed evaluating some physicochemical compounds, hydrophilic (H-AC) and lipophilic (L-AC) antioxidant capacity of eleven avocado genotypes grown in the Andes. The results show great variability in physical and chemical properties, dry matter (DM) and lipid contents with ranges of 18.4-39.3% and 10.1-23.2%, respectively. All genotypes had high oleic acid content (50.4-69.9%) and a high unsaturated fatty acid/saturated fatty acid ratio (UFA/SFA, from 3.05 to 6.05), while the unsaponifiable fraction contained mainly beta-sitosterol (140.83-235.51 mg/100 g DM) and alpha-tocopherol (17.44-71.29 mu g/g DM). Total phenolic compounds (TPC), H-AC and L-AC ranged from 0.48 to 0.88 mg EAG/g DM, 5.37 to 14.00 and 1.87 to 6.71 mu mol ET/g DM, respectively. Although the genotype influences avocado characteristics, climatic conditions in the Andean region seem to be important for the biosynthesis of metabolites of interest and should be considered in future studies.

关键词： CAPE   Casein   Nanoparticles   In vitro release   Binding mechanism  

摘要： Caffeic acid phenethyl ester (CAPE) is a phenolic substance with beneficial biological activities. However, low water solubility and bioavailability limit its applications. In this study, a nanoscaled targeted delivery system for CAPE was constructed using casein, sodium alginate (NaAlg), and Ca2+. The physicochemical properties, encapsulation efficiency, and morphology of the nanoparticles were characterized. The pH and storage stability, in vitro release rate, and the binding mechanisms between CAPE and casein were investigated. The results showed that Ca-casein-CAPE-NaAlg nanoparticles had a uniform particle size (211 +/- 5.1 nm), high encapsulation efficiency (96 +/- 3.98%) and loading capacity (7.01%). Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism (CD) analysis confirmed the combination of CAPE and casein via hydrophobic interaction. The nanoparticles remained stable in pH 5.5-7.0 and storage at room temperature for 4 weeks. The nanoparticles effectively prevented digestion of CAPE by pepsin in vitro. Hydrophobic interactions were the main force that maintained the binding of CAPE and casein. The molar ratio of CAPE to casein in the nanoparticles was approximately 7.72-8.36:1. Therefore, the newly developed nanoparticles are expected to form delivery systems that could effectively improve the stability and bioavailability of low water-soluble bioactive compounds for applications in the functional foods and dietary supplements.