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关键词： Chemical composition   Physicochemical properties   Structural properties   Antioxdiant   Grape skins   High hydrostatic pressure  

摘要： Chemical compositions, physicochemical properties, microstructure, and antioxidant capacity of skins from pomaces of five Virginia-grown grape varieties and their response to high hydrostatic pressure processing (HPP) were investigated. Dietary fiber was the predominant carbohydrate, and red grape skins had higher total and insoluble dietary fibers than their white grape counterparts. The skins from variety Traminette had the highest water swelling capacity but the lowest oil retention capacity which might be associated with their large particle size. Variety Petit Verdot skins presented the highest total phenolic/anthocyanins contents along with the highest DPPH. and ABTS. + scavenging capacities. Although HPP treatment did not significantly (P > 0.05) alter chemical composition of the grape skins, it led to decreased particle size and morphological change from flat and compact to loose and porous appearance. These microstructural changes favored water and oil retention capacities of the HPP-treated samples. HPP treatment also enhanced the aqueous acetone extraction yield in Traminette and the total phenolic and anthoyanins contents in Petit Verdot. These results indicates the potential applicability of HPP-treated grape skins as an antioxidant dietary fiber source to augment and enhance fiber-rich functional foods.

关键词： MTES based aerogel   Ambient pressure drying   Hydrophobicity   Thermal properties   Mechanical properties  

摘要： This work presents a facile synthesis approach of methyltriethoxysilane (MTES) based aerogels using pure water as the only solvent, and the effects of precursor concentration on the physicochemical properties are investigated in detail. Therein, the precursor concentration has no effect on the chemical composition but causes the denser and slenderer skeletons at the lower precursor concentration and vice versa. At the 14.4 vol% precursor concentration, the MTES based aerogels are made up of slender skeletons, having the minimum density (0.057 g/cm(3)), the maximum porosity (97.5%), and the low thermal conductivity (29.4 mW/m/K). It further finds the denser and slenderer silica skeletons cause higher compressive strength and higher Young's modulus. The TG-DSC results indicate the nice thermal stability of MTES based aerogels. In short, this research demonstrates the great competitive advantages of MTES based aerogels in the field of thermal insulation from the view of preparation method, thermal conductivity, and thermal stability. [GRAPHICS] .

关键词： Ciprofloxacin   Quaternary ammonium Salts   Dual antibacterial   antifungal agents   DNA gyrase   Antibiofilm   Metal chelation  

摘要： New ciprofloxacin/ quaternary ammonium salts 3a-e were designed and synthesized as potential antimicrobial agents. Most of the prepared derivatives showed promising dual antibacterial/antifungal activities. Compound 3e was the most potent and afforded vast spectrum antibacterial activity against S. aureus and most of the tested Gram-negative bacterial strains with MIC values ranging from 1.53-9.54 mu g/mL. Moreover, ciprofloxacin and compound 3e induced DNA cleavage in S. aureus DNA gyrase and S. aureus TOPO IV DNA by 1 and 10 mu M, respectively. In addition, docking study results agreed with results of DNA cleavage assays where all the tested compounds showed no additional significant interactions over the parent ciprofloxacin. On the other side, compounds 3e and 3f exhibited outstanding antifungal activity better than the reference itraconazole with MICs of 1.87, 4.67, and 11.22 mu g/mL, respectively, against Candida. albicans. These data suggest the prevalence of another mechanism in addition to DNA gyrase circumvention, like metal chelation, antibiofilm, and/or improvement of lipophilicity and subsequent penetration.

关键词： high‐   speed homogenization   ultrasonic treatment   soybean protein isolate   soy lecithin   emulsion stability  

摘要： BACKGROUND The properties and stability of emulsion rely greatly on the emulsification method and emulsifier. In this study, different emulsification methods (high-speed homogenization, ultrasonic treatment and their combination) were employed for the preparation of emulsions stabilized by soybean protein isolate (SPI) and soy lecithin (SLT) at three ratios. The microstructure, hydrodynamic average diameter, zeta-potential, creaming stability and low-field nuclear magnetic resonance relaxation behaviors of emulsions were investigated. RESULTS The results indicated that the influence of emulsification method was closely related to the ratio of SPI/SLT. Overall, the SPI-SLT-stabilized emulsion treated by ultrasound showed better stability and uniformity, while the combined treatment of high-speed homogenization and ultrasound was helpful in improving the uniformity and stability of SPI-stabilized Pickering emulsion. However, the SLT-stabilized emulsions all exhibited worse uniformity in terms of particle size distribution and polydispersity index. CONCLUSION These results will be helpful for selecting an appropriate emulsification method and emulsifier to improve the stability of emulsions. (c) 2021 Society of Chemical Industry.

关键词： Annual effective dose   Groundwater   Radon activity   Total dissolve solids  

摘要： This study evaluates the quality of drinking water samples (sample size = 52) taken from various locations of Pithoragarh district, Uttarakhand. The parameters include physiochemical properties viz. total dissolved solids (TDS in mg/L), electrical conductivity/salinity (mu S/cm), pH and radiological dose attributable to radon in water (mu Sv/y). TDS values for the tested samples varied within the range of 18-434 mg/L with average value of 148 mg/L. Electrical conductivity and pH for these samples was measured as 36-868 mu S/cm (average: 296 mu S/cm) and 6.8-8.2 (average: 7.2), respectively. Radon activity concentration for these water samples was measured using scintillation-based radon monitor, immediately after sampling at the location site. Radon activity concentration was measured as 0.6-81.9 Bq/L with an average value of 17.8 Bq/L. The paper also estimates the annual effective ingestion dose (mu Sv/y), annual effective inhalation dose (mu Sv/y) and total effective dose (mu Sv/y) attributable to radon in drinking water samples.

关键词： Atrato Delta   Gulf of Uraba   Sedimentation   Provenance  

摘要： The Atrato River Delta (ARD) is a unique landform of the Colombian Caribbean shaped by the hydrologic and geological framework of the Colombian Pacific. This study analyses modern sedimentation in the ARD through grain size, mineral abundances, chemical weathering and concentrations of major and trace elements in 60 surface sediment samples surveyed over fluvial, lacustrine, estuarine and marine depositional settings within six geographic sectors. Sediment size patterns decrease towards the bays into the Gulf of Uraba, varying from very fine silt to fine sand and from moderately well to very poorly sorted, implying moderate energy flows in the delta. Transport regimes vary from traction inland to suspension in the north sector, with the predominance of saltation in central and east sectors. Mineralogy shows a dominant mineral phase of quartz, followed by feldspars and plagioclase, clay minerals, pyroxenes, micas and Fe-Mg and Ti oxides, indicative of heterogeneous bedrock sources. The distribution of these minerals responds to the effects derived from sorting, degree of weathering and mineral density. The tectonic setting and provenance designate the Oceanic Island Arc as the main source of sediments. Compared to Upper Continental Crust values and regional geochemistry, samples show a depletion of SiO2, Na2O, CaO and K2O, representing high dilution processes along the delta. High abundances of other oxides (Al2O3, Fe2O3, MgO, TiO2, P2O5 and MnO), by contrast, imply oxidation processes with moderate to high weathering. High concentrations of Organic Carbon, Cl, Na, P and S, mainly at bays, indicate a saline wedge as a signature of organic matter degradation, oxidation processes, marine productivity and sediment reworking towards the Gulf of Uraba. Zn, Ni, Cu, Co and Cr remain high along the delta and indicate both natural and anthropogenic contributions. The study contributes to recent efforts to understand the sedimentary dynamics of this active tropical delta.

关键词： Aspergillus oryzae   1,4-alpha-D-glucan glucohydrolase   Fractional precipitation   Kinetics   Thermodynamics  

摘要： The aim of the study was to produce Ca2+ and Mg2+ independent raw starch hydrolyzing 1,4-alpha-d-glucan glucohydrolase (GGH) for glucose and fructose syrup production. A thermophilic GGH was produced from Aspergillus oryzae NRRL 1560. Two iso-forms of the enzyme, i.e., GGH1 and GGH2, were purified to homogeneity up to 4.93- and 8.82-fold that showed broad bands of 40 and 48 kDa on SDS-PAGE, respectively. K-m and V-max values of GGH2 were 1.315 mg mL(-1) and 70.864 mu mol mL(-1) min(-1), respectively. Enzyme showed optimum activity at 60 degrees C, pH 5.0. It displayed a broad range of pH (3.0-9.0) and temperature (30-60 degrees C) stability. Inactivation kinetics parameters were calculated as K-d = 0.014 min(-1), t(1/2) = 49.5 min, D = 164.5 min, z = 22.23 degrees C, T-m = 77 degrees C, and E-a(d) = 337.481 kJ/mol. Thermodynamics parameters for thermal unfolding were Delta G*((d)) = 264.323, Delta H*((d)) = 334.713 kJ/mol, and Delta S*((d)) = 0.211 kJ/mol K. GGH2 was activated by 1 mM Na+(18%), K+(15%), Mg2+(6%), Ca2+(1%) and inhibited by Cu2+(21%), Zn2+(10%), Mn2+(6%) at the same concentrations. The enzyme was also inhibited by 5 mM SDS (95%), DTT (8%), beta-mercaptoethanol (4%), and EDTA (2%). GGH2-hydrolyzed raw starches were in the following order rice > wheat > corn > sweet potato > potato. This is the first report on raw starch digesting enzyme from A. oryzae. All these features make this enzyme a potential candidate for industrial production of glucose/fructose syrups and ethanol from raw starch via biological conversion.

关键词： Dairy technology   Fermented dairy beverages   Goaty flavor   Volatile profile   Principal component analysis  

摘要： It has been generally proven that the goaty flavor negatively affects consumer acceptance of goat milk (GM) products. In this study, the co-fermentation of isolated new yeasts with lactic acid bacteria (LAB) was applied to improve the aromatic properties of new fermented GM beverages. Microbial count, acidity, syneresis, water holding capacity, rheology characteristics, volatile compounds (VCs), and sensory characteristics were determined. Moreover, the obtained results of VCs were visualized using a heatmap with hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results revealed that co-fermentation with Kluyveromyces marxianus strain K and SP-1 significantly increased the growth (9.74 +/- 0.07 and 9.67 +/- 0.11 log CFU/mL) and acid production (1.07 +/- 0.05 and 1.06 +/- 0.02%) of total LAB strains, respectively while enhancing the rheological properties. Results from SPME-GC-MS analysis showed that the relative content of hexanoic (4.62%), octanoic (3.08%), and decanoic (1.18%) acids which were associated with the goaty flavor decreased more in GYK (0.96, 1.09, and 0.38%) and GYS (1.30, 1.03, and 0.41%) beverages, respectively. HCA dendrogram showed that Candidaethanolica strain ATW-1 used to prepare GYA drinks was not adapting well in GM and was more similar to GY drinks. PCA bioplot showed that high content of acids, alcohols, and esters was generated throughout the fermentation. The inoculation of K. marxianus strain SP-1 into GM significantly improved FGM beverages aroma by reducing the goaty flavor and increasing the contents of total acids and alcohols thus, improving the FGM beverages by giving the balsamic, buttery, cheesy, and rosy flavors, with a little sweet taste. The study has positive prospects for the development of fermented GM with enhanced flavor for the beverage industry and other practical applications.

关键词： norovirus   adhesion   contact angle   ready-to-eat foods  

摘要： The adhesion of noroviruses to strawberry, turkey slices, ham, and cheddar cheese was studied using murine norovirus 1 (MNV-1) as a surrogate for human norovirus (NoV). Based on plaque assay, the recovery and adhesion of MNV-1 depended on the food type (turkey versus strawberry), pH of the initial suspension buffer (pH 4 versus pH 7), and food fat composition (C-8 versus C-18). Recovery of infectious particles from turkey was 68% compared to 9.4% from strawberry. On turkey, adhesion of MNV-1 was lower at pH 7 (pH of fecal matter), and virus particles adhered to this pH were recovered more easily (33,875 PFU) than at pH 4 (pH of vomitus). The presence of fat and the composition of fatty acids seemed to increase MNV-1 recovery and adherent viral particles recovered but did not affect adhesion (68% on fat-free turkey and regular turkey). Adherent MNV-1 particles recovered from stainless steel coated with saturated fatty acid (C-8, C-14, C-18) increased significantly with chain length (P < 0.05), but adhesion did not seem to change. Using liquid droplet contact angle to measure surface energy, it was deduced that hydrophobic interactions contribute considerably to the adhesion of MNV-1 to stainless steel, polyvinyl chloride, and high-density polyethylene. IMPORTANCE Ready-to-eat (RTE) foods are major vehicles of transmission of foodborne viral pathogens, including NoV. The high incidence of gastroenteritis caused by viruses is due largely to their persistence in the environment and adhesion to different kinds of surfaces in the food industry, including the foods themselves. Compared with bacteria, adhesion of viruses to surfaces is poorly understood. Better knowledge of the physicochemical parameters involved in the adhesion of NoV to ready-to-eat foods is essential to devising effective strategies for reducing the persistence and, thus, the transmission of this virus.

关键词： Biopolymers   Food pigment   PH freshness indicator   Synthetic layered silicate  

摘要： Colorimetric films containing anthocyanins can be used as intelligent food packaging materials. The present research aims to develop, characterize, and apply chitosan films containing a biohybrid based on anthocyanins from eggplant (Solanum melongena L.) peel and laponite (R). Anthocyanins were adsorbed on the laponite surface to produce biohybrids (BH) and then used to manufacture edible films by casting method. The BH increased the thickness and reduced the solubility in water of chitosan films. Furthermore, the residual mass and opacity of films increased with the presence of BH. Chitosan films containing BH showed change color properties from grey (initial film color) to red or yellow colors when exposed to buffer solutions with acid and basic pH, respectively. Finally, chitosan films containing BH were used to monitor meat freshness at different temperatures (- 20, 4, and 20 degrees C) by means of film color alterations which was correlated with total volatile basic nitrogen produced in meats during the storage. Based on physicochemical and colorimetric results, the BH based on anthocyanins and laponite (R) is an interesting material to manufacture intelligent films for the food packaging sector.