The present investigation aims to examine the influence of textural, structural and chemical properties of biomass chars on the CO2 gasification rate. Various lignocellulosic biomass chars were ...prepared under the same conditions. Different analytical techniques were used to determine the char properties such as Scanning Electronic Microscopy, nitrogen adsorption manometry, Raman spectroscopy and X Ray Fluorescence. Gasification tests were carried out in a thermobalance under 20% CO2 in nitrogen at 800 °C.
Significant differences of the total average reactivity were observed with a factor of 2 between the prepared chars. Moreover, different behaviors of gasification rate profiles versus conversion were obtained. This difference of behavior appeared to be correlated with the biomass char properties. Hence, up to 70% of conversion, the gasification rate was shown to depend on the char external surface and the potassium content. At higher conversion ratio, a satisfactory correlation between the Catalytic Index and the average gasification rate was identified. The results highlight the importance of knowing both textural and structural properties and mineral contents of biomass chars to predict fuel reactivity during CO2 gasification processes. Such behavior prediction is highly important in the gasifiers design for char conversion.
•CO2 gasification reactivity of various lignocellulosic chars were examined.•Chars properties affect strongly samples gasification behavior.•Initial gasification rate is affected by external surface, K content and D3/G ratio.•Gasification rate behavior depends on the Alkali index at high conversion.
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•NiFe-LDH/Hal composites with tunable morphology were developed for CO2 uptake.•Optimum calcination temperature of halloysite for best CO2 adsorption performance was detected to be ...600℃.•NiFe-LDH/Hal600 displayed highest CO2 adsorption capacity of 60.7 mg g−1.•Open mesoporous structure and high pore volume favor the CO2 adsorption.
The cost- and use-effects for solid CO2 adsorbents have accelerated development of the clay-based adsorbents. Herein, a series of NiFe-layered double hydroxides/halloysite (NiFe-LDH/Hal) composites were fabricated via facile hydrothermal strategy using calcined halloysites (Hal) as supports. Depending on treatment temperatures of halloysite, the supported NiFe-LDH exhibited different morphologies in form of nanoparticle or intertwined nanosheets. Based on the distinct morphology, these NiFe-LDH/halloysite composites displayed different textural properties and CO2 adsorption performance. Particularly, the sample NiFe-LDH/Hal600 using halloysite calcined at 600 °C as support possessed 3D hierarchical structure, and displayed superior CO2 adsorption capacity of 60.7 mg g−1 and 40.3 mg g−1 at 273 K and 298 K, respectively, much higher than those of NiFe-LDH/Hal composites supporting LDH nanoparticles. The high isosteric heat of adsorption calculated from Clausius-Clapeyron equation (21.7 kJ mol−1) indicated the strong interaction between basic NiFe-LDH surface and CO2 molecules. It was validated that the dehydroxylation and forming of silanols groups during calcination process changed the activity of internal and external surface, resulting in distinct morphology and distribution difference of the supported NiFe-LDH. The prepared clay-based composites displayed satisfying recyclability of CO2 adsorption at a high retention level after 25 cycles of adsorption–desorption.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With advantages of long shelf life and high convenience, frozen steamed bread (FSB) is suitable for commercialization and industrialization. However, FSB has to be reheated before consumption. Since ...steam reheating is the most commonly used method for steamed bread reheating, the quality variation of FSB during the steam reheating process was evaluated in this research. Because of the simultaneous energy and moisture transfer, both the temperature and moisture content of reheated FSB gradually increased during steaming process. Starch gelatinization and crystallinity results showed that the retrograded starch was gelatinized again during steaming process. With the increase of steam reheating time, the increase of springiness and resilience as well as the decline of hardness and chewiness indicated the improved textural properties of steamed bread. Considering the sensory evaluation, the optimal steaming time was about 12 min with a maximum sensory evaluation score of 93.3. However, the springiness, resilience and sensory evaluation results of reheated FSB were still lower than those of the fresh steamed bread. The microstructure results showed that the damaged gluten network of FSB could not be recovered by steam reheating.
•The retrograded starch was gelatinized again by steam reheating.•The mechanically damaged gluten network cannot be recovered by steam reheating.•Textural properties improved continuously during the steam reheating process.•The textural and sensory evaluation properties were still below the fresh samples.
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•The results of fracture toughness KIIc of fly ash concrete were validated through DIC method.•There is a correlation between KIIc parameter obtained by using two measuring ...devices.•Fracture processes based on the images of major strain and displacement X were analyzed.•An original solution for measuring the actual length of a crack propagating in the material were presented.•A new sophisticated crack tip tracking (CTT) method was introduced.
This article focuses on the analysis of fracture processes in fly ash (FA) concrete considering the second model of cracking. The basic parameter of fracture mechanics in concrete elements according to Mode II fracture, i.e. KIIc, was determined. Two measuring devices were used in the studies. One of them was the Digital Image Correlation (DIC), which is now a popular and extensively used metrology technique. During the experiments, an attempt was made to validate the results of fracture toughness obtained in strength press tests. The main goal of the studies was to confirm the convergence and determine the discrepancy ranges, between the KIIc results obtained on the MTS 810 press and using the DIC technique. During the investigations a new concept was proposed in the analysis of concrete fracture processes under Mode II using the DIC method, i.e. evaluation the fracture toughness of the composite by the direct testing of the material with an initial defect – in the crack propagation area (Fig. 7b). In addition, it was attempted to determine the usefulness of the DIC system for the analysis of initial cracks development in concrete elements subjected to shear. For this purpose, basing on the images of major strains and displacements in the X direction, an in-depth assessment of the initial cracks growth was made. The article also presents an original, sophisticated solution for measuring the actual length of a propagating crack in the material with the use of the crack tip tracking (CTT) method. Principal strains ε11 were used to visualise the cracks, while their length was determined as the sum of the relative crack increments (generated at successive stages of the loading of the specimen) measured on the XY plane (rel XY).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Corn starch citrate (CSC) is a type IV resistant starch (RS) and its inclusion in bakery products has several health benefits. Therefore, in this study, 0, 10, 20, 30 and 40% of wheat starch (as the ...main constituent of wheat flour) was replaced by CSC and its influences on solubility, water absorption, scanning electron micrographs (SEM), pasting properties, texture profile analysis (TPA) and stress-relaxation behavior of wheat starch gels were determined. By the increase in CSC level, solubility and water absorption were decreased. The CSC addition led to an increase in the pasting temperature but decreased other pasting parameters. The control wheat starch gel had the highest firmness, cohesiveness, springiness, gumminess and chewiness. However, inclusion of CSC decreased these parameters. Stress-relaxation data showed that the Ee, E1 and τ1 parameters were decreased by the increase of CSC level and the electron micrographs revealed that the control starch gel had a denser structure and addition of CSC formed gels with larger cells and thinner cell walls. To summarize, increasing the SCS substitution level provided a remarkable decrease in resistance of wheat starch gel as revealed by the experiments.
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•Solubility and water absorption were decreased with the increase in CSC level.•CSC increased pasting temperature but decreased other pasting parameters.•By the increase of CSC level, the textural parameters of gels were decreased.•CSC containing gels had larger cells and thinner call walls.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This research aimed to reduce the loss of juiciness and textural properties of prepared beef steak during freezing by applying low voltage electric field (LVEF). Results showed that LVEF assisted ...freezing (LVEFF) speeded up the freezing process by 29.8% of the steak at the layer spacing of 30 cm (LVEFF-30). And LVEFF-30 efficiently reduced the press loss and thawing loss of the prepared steak by 21.2% and 47.4%, respectively. Textural analysis showed that LVEFF could enhance the hardness and tenderness of the thawed steak comparing with AF (air-blast freezing). Analysis of the size and distribution of ice crystals in muscle revealed that LVEFF could promote more uniform crystal nuclei and more rapid ice nucleation than AF. Low field nuclear magnetic resonance showed that LVEFF reduced the migration of immobilized water to free water, where LVEFF-30 was the most efficient manner. In conclusion, LVEFF could efficiently reduce the juiciness and textural loss of prepared beef steak during freezing comparing with AF.
The juiciness and textural properties may seriously lose in traditional freezing method (AF), which reduces the quality of the prepared meat products and are unfavorable to consumers. LVEF represents a safe and energy-efficient physical processing technique based on electrostatic field, which has never been utilized in freezing meat products. Herein, the effect of LVEF on the juiciness and textural loss of prepared beef steak during freezing and the underlying mechanism will be discussed. The results will provide guidance for utilizing LVEF in the freezing storage and transport of prepared beef steak.
•Low voltage electrostatic field was applied to the freezing process of prepared meat products.•The juiciness, hardness and tenderness of the frozen prepared beef steak were enhanced by low voltage electrostatic field.•The underlying mechanism was elucidated by migration of water molecules.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The aim of the study was to investigate the effect on physical and sensory quality of cookies on supplementation with partially hydrolyzed guar gum (PHGG) as soluble fiber at level of 1–5%. The ...effect of PHGG level, water level and baking time were studied on cookie spread factor, cookie hardness and overall sensory acceptability. The second order model obtained for spread factor, hardness and overall sensory acceptability of cookies revealed coefficient of determination of 0.9392, 0.9502 and 0.7582 respectively. Physical and sensory properties of cookie revealed significant changes with variation in PHGG level, water level and baking time. The optimized values for all the three independent variables i.e. PHGG level, water level and baking time were 2.21%, 4.81% and 8.81 min, respectively. This study revealed that partially hydrolyzed guar gum can be successfully incorporated in cookies for the enrichment of soluble dietary fiber.
•Partially hydrolyzed guar gum was used as novel and rich soluble fiber source.•Soluble fiber fortified cookies were prepared.•PHGG addition improved textural characteristic of cookies.•Soluble fiber fortification reduced the spread ratio of cookies.
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The effects of different mixing parameters (vacuum mixing and mixing time) on oat (70% oat flour) and wheat noodle dough were investigated on the basis of textural properties and gluten formation. ...The results showed that at a vacuum degree of −0.06 MPa and mixing time of 10 min, oat and wheat dough sheets exhibited the highest resistance to extension and glutenin macropolymer (GMP) content, and had the most compact and uniform gluten network. Compared with wheat noodle dough, oat dough had lower resistance to extension, lower tightly bound water content, and higher GMP content. Microstructural examination showed that oat noodle dough had a more aggregated distribution of gluten protein compared with wheat noodle dough under the optimum mixing parameters. Furthermore, the poor binding ability of vital wheat gluten with water molecules caused the indexes of oat noodle dough to be more strongly affected by the changes in mixing parameters than wheat noodle dough.
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•Noodle dough containing 70% oat flour was more affected by the change of mixing parameters.•The binding ability of exogenous vital wheat gluten with water molecules was poor.•Remarkable gluten protein aggregates were observed in oat noodle dough.•Optimizing mixing parameters could improve the processing quality of oat noodles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As meat is deficient in dietary fiber, it is combined with different dietary fibers from cereals, fruits, and vegetables. Interactions of pectin and cellulose with actin, myosin, and collagen were ...studied. It was found that the total number of hydrogen bonds between pectin-actin, cellulose-actin, pectin-myosin, cellulose-myosin, pectin-collagen and cellulose-collagen is 8, 7, 12, 14, 6 and 6 respectively. The free energy of binding for these complexes was found to be −18.41, −13.22, −18.41, −9.54, −12.89 and −4.02 KJmol-1, respectively. van der Waals bond, hydrogen bond, and desolvation energy components for pectin and cellulose with actin, myosin, and collagen were −20.54 and −27.36 KJmol-1, -24.27 and −22.84 KJmol-1, and -20.13 and −18.03 KJmol-1, respectively. A higher negative free energy (ΔG) of binding was found, which indicates an efficient interaction between dietary fiber and animal protein.
•The H bonds formed between dietary fiber and the meat protein was estimated.•The free energy of binding for dietary fiber and meat protein was calculated.•Van der Waals and desolvation energy of fiber and meat protein were estimated.•In-Silico study can help to understand textural changes in meat products.
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