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关键词： Physicochemical properties  

摘要： The effects RG-І pectin (0.5, 1, 2, 5 and 10%, w/w) on the gelatinization behaviour, gel structure and digestibility of potato starch were characterized by means of rapid viscosity analysis (RVA), rheometry, scanning electron microscopy (SEM) and in vitro digestion. Results indicated that the addition of RG-I pectin significantly decreased the peak and breakdown viscosity and prolonged the pasting temperature of potato starch, but increased the setback viscosity. Meanwhile, the swelling power and amylose leaching of starch granules were restrained because of RG-I pectin adsorption on the starch granules surface. The presence of RG-I pectin also decreased the G’ values of potato starch gel but increased the tan δ values (especially for 1%), indicating that RG-І pectin decreased the 3D network formation of potato starch gel. The microstructure analysis indicated that RG-I pectin decreased the formation of the gel structure, which might place constraints on the relative amylose concentration in the continuous phase. The addition of RG-I pectin also reduced the rapidly digestible starch (RDS) content and increased the slowly digestible starch (SDS) content, while no significant differences of resistant starch (RS) content was observed. Those results indicated that RG-I pectin could affect the physicochemical properties of potato starch and modulate its digestibility and might be a potential option for producing starchy food with lower digestibility. © 2021 Elsevier Ltd

关键词： Microwave sintering   Cation distribution   Magnetocrystalline anisotropy   Dielectric dispersion   Gas sensor  

摘要： A series of Ni0.5Zn0.5AlxFe2-xO4 (0.0 <= x <= 0.25) nanoferrites have been prepared by sol-gel auto combustion and followed by sintering in a microwave oven at 1100 degrees C for 30 min. Pure cubic spinel phase was confirmed from the indexed planes in XRD patterns. The experimental lattice parameter (a) was found to be in the range of 8.3908-8.3509 angstrom in the decreasing order with the doping level of Al3+ ions. The sharp diffraction peaks indicate the crystalline nature of the samples. The microwave sintering is promoting the crystallinity with the substitution of Al3+ ions (42.8-54.4 nm). The saturation magnetization (M-s) gradually decreased with the substitution of Al3+ ions, and highest value of 61.2 emu/g was reported. The dilution of A-B superexchange interaction can be expected from the variation of bond angles. The coercivity is predominantly dependent on the magnetocrystalline anisotropy. Normal dielectric dispersion was observed in the present series of ferrite samples, and the dielectric constant is found to be composition dependent. The low value of dielectric constant was observed for the compositions x = 0.15 and x = 0.25. The present ferrite systems are showing good sensor response to NH3 and least response to H-2. In the tested ferrite systems, the composition x = 0.25 is an appropriate selective for sensor fabrication to test NH3 gas.

关键词： Blanching pretreatment   Drying kinetics   Microwave-vacuum drying   Power level   Quality  

摘要： In this study, drying kinetics and quality of purple-fleshed sweet potato (PFSP) subjected to microwave-vacuum drying were investigated. The effects of hot water and steam blanching pretreatment on physicochemical characteristics of the dried products were also considered. The samples were dehydrated in a custom-made microwave-vacuum system at different power levels including 450, 600 and 850 W. Hot air drying at 70 degrees C was also conducted for comparison. The results showed that drying time of PFSP under microwave-vacuum conditions ranged from 6 to 12 min, significantly reduced as compared to that of hot air drying (600 min). The improvement of drying rate was also evidenced by increased effective moisture diffusivity (2.22 x 10(-7)-4.05 x 10(-7) m(2)/s) of the samples. Drying kinetics of PFSP was best fitted by Page and logarithmic model with R(2)ranging from 0.991 to 0.998, and RMSE from 0.016 to 0.030. PFSP dried under microwave-vacuum condition had lower water absorption index and swelling capacity than hot air drying. Color, antioxidant activity and total phenolic content of dried PFSP were also improved under microwave-vacuum drying. The effects of blanching pretreatment on quality of dried PFSP were more dominant in hot air than microwave-vacuum dried samples.

关键词： Physicochemical properties   Land use system   Toposequence Position   Lake Victoria basin  

摘要： Patterns of soil properties in highland environments remain poorly understood and limited knowledge exists on soil quality with respect to land use systems and topographic configurations. In this study, patterns of 12 surface soil physicochemical properties were assessed over a period of three years with respect to land use systems and toposequence positions in the Rwizi catchment of the Lake Victoria Basin. Four land use systems constituting mulched banana, unmulched banana, grassland and tree plantation, and three toposequence positions stratified as footslope, midslope and summit were considered and three replications were applied resulting in a total of 36 sites for soil properties measurements over a three-year period. Topographic attributes (elevation, slope gradient, slope aspect, and location) were collected at each site and correlated with surface soil properties. With the exception of pH and Ca, surface soil physicochemical properties are revealed to be optimal in the catchment. Greater spatial variation was found with soil chemical properties (8-57%) compared to physical properties (7-19%). Land use system registered significant effects (p < 0.05) for all soil chemical properties, as well as bulk density. Toposequence position is shown to have significant (p < 0.05) effects on soil pH, Soil Organic Matter, available P, N and soil texture. The effect of toposequence position revealed better soil quality along the catenary sequence summit > footslope > midslope. Strong and significant regression coefficients (r(2) > 0.6, p < 0.05) for topographic attributes were found with soil pH, available P, K, Ca, Mg and sand. Overall, the land use system effect supersedes toposequence position in accounting for variations in surface soil physicochemical properties. Although environments of the Lake Victoria Basin are subject to intense agricultural activity and are usually assumed to be degraded, surface soil physicochemical properties in this part of the catchment ref

关键词： N-methyl-N-nitroguanidine   MeNQ   physicochemical properties   photolysis   hydrolysis   environmental fate  

摘要： 1-methyl-3-nitroguandine (MeNQ) is being pursued as an insensitive munition to replace legacy munitions such as TNT and RDX. This study was intended to determine the basic physicochemical properties of MeNQ as well as potential environmental fate pathways. The solubility of MeNQ was determined to be 12.92 +/- 0.52 g/L and aqueous photolysis was found to efficiently degrade the munition, where its quantum yield and half-life were found to be 0.009 and 0.59 days, respectively. Hydrolysis was an insignificant degradation pathway resulting in 8.1 % degradation at pH 4, 2.6 % at pH 7, and 6.2 % at pH 9 after five days at an elevated temperature. Volatilization at environmentally relevant conditions was found to be insignificant as the molecule thermally degrades, leading to an inability to calculate Henry's Constant for volatilization from water. Spectroscopic (UV-vis, FTIR, NMR) and analytical (HPLC) studies were undertaken and are shown alongside the parent molecule, NQ, for comparison to characterize the emerging munition.

关键词： Cholesterol  

摘要： Traditional Algerian Bouhezza cheese is produced inside animal skin-bags with a fermented, buttermilklike product, Lben. Two Bouhezza cheeses were simultaneously made in two skin-bags in each of two sequential years. Bags had a defined filling sequence (first or second) with Lben for the same batch. Samples from each bag were collected at days 7, 30 and 60 to obtain 6 samples per year and a total of 12 samples. The effects of number of days and filling sequence on gross composition, alpha-tocopherol, cholesterol content and stability were evaluated. With more days, dry matter, protein, fat, cholesterol and alpha-tocopherol contents increased and pH decreased (P < 0.01). At 60 d 100 g of Bouhezza contained 39.2 +/- 7.04 mg of cholesterol. Cholesterol was never protected and oxidation was evident. Oxidation was highest in cheeses from the second-filled bags during the first 30 d of production (P < 0.05). (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Physicochemical properties  

摘要： Aqueous solutions of lactoferrin (LF) were subjected to thermal processing (72, 80, 85, 95 degrees C for 15 s) using a rheometer. Despite the low protein concentration and low ionic strength of the LF solutions, analyses post-processing revealed the presence of heat-induced, covalently-linked, protein aggregates. Aggregation was accompanied by increased surface hydrophobicity and zeta-potential and changes to the secondary structure of the protein, including reduction in the proportion of alpha helix domains coupled with increased intermolecular beta sheet structures. The native red colour of the protein was lost upon thermal processing, not attributable to the release of LF-bound iron. Micro-differential scanning calorimetry showed LF to be irreversibly denatured on heating with endotherms observed at 58.7 degrees C (apo-LF) and 89.6 degrees C (holo-LF). Thermal processing at 72-95 degrees C resulted in irreversible changes to the structural and physicochemical properties of bovine LF, whereby the lowest heating intensity had the least impact on LF structure. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Diastase   DPPH   FRAP   HMF   Plateau honey   Proline  

摘要： The aim of this study is to investigate the physicochemical properties, antioxidant activities, and total phenolic contents of the plateau (multifloral), chestnut, rhododendron, and acacia honey collected from Ordu province in Turkey. The rhododendron honey had the highest acidity (p < 0.05) while the chestnut honey showed the highest conductivity (1.13 +/- 0.25 mS/cm) among all (p < 0.05). The highest diastase activities and the lowest HMF contents were determined in the multifloral and chestnut honey. Considering the DPPH and FRAP assays, the multifloral honey showed the highest antioxidant activity. Accordingly, the highest total phenolic content was determined in the multifloral honey followed by rhododendron, chestnut, and acacia honey. A moderate correlation was determined between the total phenolic content and antioxidant activities (r = 0.575 for FRAP and r = 0.697 for DPPH). Consequently, the plateau honey could be recommended for nutritional and health purposes due to its relatively higher antioxidant activity and total phenolic content together with relatively lower HMF content and higher diastase activity. Considering that Ordu is the largest honey producer city in Turkey, the second top honey producer country, this work could shed light for future studies and be taken as a reference providing insights on the characteristics of different types of honey for both local and worldwide producers.

关键词： Condensed milk   Maltodextrin   Rheological properties   Microstructure  

摘要： In this study, the effect of replacing sucrose with fructose as well as carrageenan gum with maltodextrin and using lactose to produce sweetened condensed milk as a high-consumption dairy dessert was investigated. Physicochemical, microstructural, microbial, and sensory parameters including acidity, pH, viscosity, particle size, color, total viable count (TVC), mold and yeast, odor, taste, color, texture, and overall acceptability were evaluated during the 30-day storage period. The results demonstrated that with increasing the level of maltodextrin and fructose replacement, the acidity, particle size, organoleptic scores, redness and yellowness increased, and the pH, viscosity, and lightness in the product decreased (p < 0.05). The images obtained from scanning electron microscopy revealed that the number of cavities decreased and the size of the cavities increased with increasing the percentage of maltodextrin replacement. Although the number of cavities increased with increasing the fructose level, the size of the cavities decreased (p < 0.05). The highest general acceptance score was related to T5 samples which had 50% and 100% replacement of fructose and maltodextrin, and contained 0.03% lactose.

关键词： Wheat gluten   Nano-silica   Natural absorbent   Bioactive   Red grape pomace  

摘要： In this study, a biodegradable wheat gluten (WG) film containing calcium chloride and nano silica (WG/CaCl2/SiO2) was prepared and the physicochemical properties of the film were investigated. Finally, the WG/CaCl2/SiO2 film was used as a polymeric adsorbent for extraction of bioactive compounds from red grape pomace. The properties of the composite film, including thickness, water vapor permeability (WVP), solubility, antioxidant activity and mechanical property were investigated. FT-IR, SEM, XRD and DSC tests were performed to investigate the physical, morphology and thermal properties of film. The results showed that the addition of SiO2 decreased the WVP because these nanoparticles can fill the porous cavities of the film matrix. Furthermore, SiO2 caused to improve the water resistance of the film. With the addition of SiO2, the antioxidant content of the films increased compared to the control film. The addition of SiO2 to the film decreased the crystal property and addition of CaCl2 increased the crystal property of the film. In the second step, the optimum film as adsorbent was used to extract of the bioactive compounds from the red grape pomace. For this purpose, total phenol, flavonoid and anthocyanin content were measured before and after the extraction by film, and the optimum extraction conditions were obtained by the desirability function method. At optimum extraction condition, the phenolic compounds were extracted with 76.9% efficiency and optimum extraction temperature and time were 20.5 degrees C and 27.1 h, respectively. Due to the low solubility of WG/CaCl2/SiO2 film in water and its appropriate thermal and mechanical stability, the WG/CaCl2/SiO2 film in different aquatic environments can be used to extract bioactive compounds of fruit pomace.