Gelatinous State Research Articles

Impact of Salinity on the Erosion Threshold, Yield Stress, and Gelatinous State of a Cohesive Clay

AbstractClay is the main component that contributes to sediment cohesiveness. Salinity impacts its transport, which controls the electrochemical force among the sediment grains. Here, we quantify the impacts of salinity on the erosion threshold, yield stress, and the microstructures of a fluorescently labeled smectite clay, laponite, by combining flume experiments, rheometer measurements, and macro‐ and microscopic imaging. We show that the critical shear stress for clay erosion, τb,crit, increases by one order of magnitude with increasing salinity when salinity <1.5 ppt and slightly decreases when salinity >1.5 ppt showing a weaker dependency upon salinity. We further show that the yield stress, τy, of the clay remains roughly a constant at salinity less than 1.5 ppt and decreases by over one order of magnitude at salinity larger than 1.5 ppt. This change in the dependency of τb,crit and yield stress on salinity corresponds to a change in the gelatinous state of clay, from gel‐like structures to phase‐separated structures as salinity increases. Our results provide a quantitative characterization of the dependency of clay erosion threshold and yield stress on salinity and highlight the importance of the clay gelatinous state in controlling clay transport.

Pasting and rheological properties of [formula omitted]- amylase treated proso millet starch as affected by hydroxypropylation and cross-linking in its granular and gelatinized state

The effect of hydroxypropylation and cross-linking on the pasting and rheological properties of α- amylase treated proso millet starch in granular as well as gelatinized state was investigated. The chemical modification of enzyme pre-treated starch showed significant changes (p < 0.05) in the swelling and solubility behavior. Amylose content and water binding capacity of the starches ranged from 16.72 to 21.26% and 1.23–1.53 g/g, respectively. The pasting profile of the modified starch gel (at 6% concentration) revealed a significant decline (p< 0.05) in peak viscosity. The Herschel-Bulkley model used to characterize the steady shear properties revealed that the flow behavior was non-Newtonian pseudoplastic. The flow behavior index (n) and consistency index (K) for starch pastes at 4% concentration ranged from 0.69 to 0.91 and 0.26 to 0.77 Pa.sn, respectively, whereas at 6% concentration, the values ranged from 0.45 to 0.71, and 0.46 to 11.35 Pa.sn, respectively. Dynamic rheological characteristics demonstrated that starch pastes exhibited dominant elastic behavior. The presence of hydroxypropyl groups was confirmed by FT-IR spectroscopy, with the noticeable band stretching at OH, CH, and CO. This modification approach can be exploited to prepare proso millet starch with tailored functional characteristics for desirable food applications.

Design and Evaluation of Paeonol-Loaded Liposomes in Thermoreversible Gels for Atopic Dermatitis.

Paeonol (PAE) is a hydrophobic drug. In this study, we encapsulated paeonol in a lipid bilayer of liposomes (PAE-L), which delayed drug release and increased drug solubility. When PAE-L was dispersed in gels (PAE-L-G) based on a poloxamer matrix material for local transdermal delivery, we observed amphiphilicity, reversible thermal responsiveness, and micellar self-assembly behavior. These gels can be used for atopic dermatitis (AD), an inflammatory skin disease, to change the surface temperature of the skin. In this study, we prepared PAE-L-G at an appropriate temperature for the treatment of AD. We then assessed the gel's relevant physicochemical properties, in vitro cumulative drug release, and antioxidant properties. We found that PAE-loaded liposomes could be designed to increase the drug effect of thermoreversible gels. At 32 °C, PAE-L-G could change from solution state to gelatinous state at 31.70 ± 0.42 s, while the viscosity was 136.98 ± 0.78 MPa.S and the free radical scavenging rates on DPPH and H2O2 were 92.24 ± 5.57% and 92.12 ± 2.71%, respectively. Drug release across the extracorporeal dialysis membrane reached 41.76 ± 3.78%. In AD-like mice, PAE-L-G could also relieve skin damage by the 12th day. In summary, PAE-L-G could play an antioxidant role and relieve inflammation caused by oxidative stress in AD.

Use of pullulanase as a biocatalyst for starch hydrolysis: Part 1. Study of the effect of pullulanase on maize amylopectin starch

The use of debranching enzymes in starch hydrolysis is a topical direction for obtaining new types of starch products with controlled properties and a potential for the further use. The aim of the work was to study an effect of pullulanase (EC3.2.1.41) on maize amylopectin starch in the native and gelatinized state. The objects of the research were maize amylopectin starch and enzyme preparation Promozyme D6 (Novozymes, Denmark). High-performance liquid chromatography (HPLC) was used to determine the carbohydrate composition of hydrolysates. The mass fraction of reducing substances (RS) was determined by the Lane and Eynon method. A rotational viscometer was used to measure dynamic viscosity of the starch hydrolysis products. It was found that analyzed starch in the native state showed low enzymatic sensitivity to the action of pullulanase with insignificant changes in viscosity, solubility and iodine binding capacity of the samples. Pullulanase showed the highest effect on gelatinized starch during the first eight hours of incubation. After eight hours, the maximum degree of starch hydrolysis by pullulanase at a dose of 10 units/g dry matter (DM) was 4.7% on DM basis, iodine binding capacity of the hydrolysate was D600 = 0.343 (in the control experiment D600 = 0.154), and the viscosity of the hydrolysate decreased from 7887 mPa · s to 4.3 mPa · s. Hydrolysates cooled to 8 °C and held for 20 hours along with hydrolysates that were not cooled showed high susceptibility to attack by glucoamilase (97–98%) at 60 °C and 24 hours of saccharification, which suggested the absence of their resistance to the action of glucoamilase in the conditions of the experiment. The use of pullulanase in dextrinization of the analyzed starch, which was gelatinized and partly hydrolyzed by α-amylase (RS6.1%), enabled obtaining hydrolysates with the mass fraction of reducing substances in a range of 10–24% on DM basis with the process duration of 2 to 24 hours and the enzyme dose of 2–10 units, which contained mainly maltotriose, maltohexose and maltoheptose with their total amount of 45–60% on DM basis. The results indicate a need for further research of the biocatalytic action of pullulanase to develop new methods for enzymatic modification of starch.

INTRODUCING EXHALED HUMAN BREATH WATER VAPOR AS PROPOSED MECHANISM INFLUENCING SUPERFICIAL CUTANEOUS WOUND HEALING

The concept that moist wounds heal faster than dry wounds was introduced in 1962. Most recently, in 1990 the concept was revisited with the introduction of a highly permeable wound dressing exposed to water vapors. The latter allows for water as a humidifying agent. Ideally, acceleration of superficial wound healing had been accomplished by the introduction of a highly water vapor permeable wound dressing. The breathable property allows for water vapor to interact with already present fibrin(ogen) material in blood clots. This manuscript adds a mechanism for the ultimate undisturbed success in cutaneous wound healing, being the dependency on a continuos supply of water vapor. In vitro experiments are introduced showing the cessation of exhaled human breath vapor onto a dry human blood smear as the end point of said interaction. Additionally the experiments were reproduced by exposing the blood smears to steam (water vapor) generated by machinery. In conclusion, exhaled human breath water vapor blown onto a blood clot has the same effect as water vapor emitted by machinery boiling water. Both causing a disappearance of the clot organized fibrin strands into a semisolid gelatinous state. Additionally, discontinuation of the water vapor infusion is also documented triggering a return of organized fibrin strands, albeit of greater intensity.

Instant quinoa prepared by different cooking methods and infrared-assisted freeze drying: Effects of variables on the physicochemical properties

The effects of cooking methods (pressure cooking, microwave cooking, and atmospheric pressure cooking) and infrared-assisted freeze drying (IRFD) on drying characteristic, crystalline structure, pasting property, rehydration behavior, microstructure, texture, and flavor of instant quinoa samples were investigated. Results showed that IRFD significantly reduced the drying time needed for freeze drying (FD). The crystalline structure of starch in raw quinoa was destroyed in cooking process, IRFD process well maintained the gelatinized state of quinoa samples. The pressure cooked samples owned the highest porosity and best rehydration ability. Pressure cooking and microwave cooking caused the softer and thicker texture of rehydrated instant quinoa samples. As for the flavor of quinoa sample, IRFD possessed the stronger retention ability compared with FD. In summary, pressure cooking and IRFD could be the applicable processing methods for the production of instant quinoa product or other dehydrated instant product with high quality.

Endoscopic application of novel, infection-free, advanced hemostatic material: Its usefulness to upper gastrointestinal oozing.

BackgroundSelf‐assembling peptides (TDMs) comprise synthetic amphipathic peptides that immediately react to changes in pH and/or inorganic salts to transform into a gelatinous state. The first generation of these peptides (TDM‐621) is currently used as a hemostatic agent in Europe. However, TDM‐621 exhibits slow gel‐formation and low retention capabilities on tissue surfaces. The second generation (TDM‐623) was therefore developed to encourage faster gel‐formation and better tissue‐sealing capabilities.AimThe aim of this study was to verify the efficacy of TDM‐623 in terms of its hemostatic effect in endoscopic surgery.Materials and methodsEvaluation of the hemostatic effect in endoscopic surgery (animal study) was performed using eight porcine in spine position. Following systemic heparinization, we established a “bleeding model” by endoscopic grasping forceps on the anterior walls of the stomach and duodenum. In the hemostasis method, an endoscope with a distal hood was brought into contact with the bleeding point, and 1 ml TDM‐623 was applied to the wound. After TDM‐623 gelation, the endoscope was removed, and the acute hemostatic effect (after 2 min) was confirmed.ResultIn the endoscopic bleeding model, 17 of the 23 cases (74%) showed complete hemostatic effects on the anterior wall of the stomach, and 18 of the 20 cases (80%) on the anterior wall of the duodenum, respectively. None of the applied gels were displaced from the anterior walls of the stomach and duodenum.ConclusionThe new self‐assembling peptide (TDM‐623) showed high hemostatic effects. TDM‐623 had potential usefulness for upper gastrointestinal endoscopic surgery.

Supervariate ceramics: biomineralization mechanism

Ceramics are key components of life, forming elaborate and diverse structures found in coccolith, shells, skeletons, and teeth. In materials research, however, one generally finds ceramics difficult to process because of their high hardness and melting points. How organisms effortlessly build stunning ceramic architectures, in water and at mild temperature, remains a long-standing mystery to scientists. This study discloses that biomineralization likely operates through a supervariate mechanism based on multi-ionic solutions, a mechanism that enables convenient phase and kinetic regulation through stress control. Specifically, from solutions of multiple ionic components, bioceramics with highly variable (supervariate) compositions are first produced in a gelatinous state of exceptional stability, which offers convenience in material storage, transportation, molding, and processing. Counter-intuitively, the supervariate wet gels can be solidified by simply compacting them under a mild force, whereas the formulas (e.g. carbonates or phosphates), hydration levels, and phases (amorphous or crystalline) of the resultant bioceramics can be tailored. Furthermore, we propose that the biogenic amorphous minerals (e.g. amorphous calcium carbonate) are very likely stabilized by constricting their volume at the microscale, so that they are prohibited from undergoing the prerequisite dehydration step (which requires extra volume) preceding crystallization. The new biomineralization mechanism described here answers a pivotal question on bioceramics of life.

Effect of multi-mode dual-frequency ultrasound irradiation on the degradation of waxy corn starch in a gelatinized state

Ultrasound as “green chemistry and technology” can considerably modify the component, structure, and properties of starches derived from diverse plants. In the current study, the effect of ultrasound frequency modes on the degradation of gelatinized waxy corn starch (GWCS) was investigated. The frequency modes include single-frequency modes of 20, 40 kHz (SM-20 and SM-40), and dual-frequency of 20 and 40 kHz in sequential mode (SeDM) and simultaneous mode (SiDM). Results showed that ultrasound irradiation significantly decreased (p < 0.05) the Mw of GWCS under all the frequency modes compared to the native starch. Besides, reductions in Mw enhanced by dual-frequency ultrasound were higher than those enhanced by single-frequency ultrasound. For dual-frequency modes, the reductions in Mw of SiDM were higher than those of SeDM, indicating that the degradation of SiDM was the most serious. The significant decreases in the proportion of B3 chains, and increases in the proportion of A chains of GWCS irradiated by ultrasound indicated that the larger molecules were preferentially degraded. The results of 1H NMR spectroscopy showed that both α-1,4- and α-1,6-glycosidic bonds of starch were damaged by ultrasound irradiation, and the degree of branching (DB) of GWCS irradiated by SiDM was the lowest. In conclusion, the dual-frequency ultrasound can be used as an efficient and low-cost method to facilitate the degradation of amylopectin.

Seed development and oil body dynamics of tree peony

This study aims to reveal the developmental process and structure of seeds and oil bodies of tree peony, to provide a scientific basis for the development and utilization of such woody oil plants. In this study, the fruits of P. ostii were selected as the research material to examine the changes during the development of fruits and seeds, the structural changes of the endosperm, embryo, and the seed coat along with the accumulation process of the oil bodies. Besides, using transmission electron microscopy the process of the oil body synthesis was closely observed. The resultant karyotype of the endosperm indicated that the seed changes from liquid to gel and finally becomes solid, filling the entire interior section of the seed at maturity. When the endosperm was in the liquid state, the intracellular oil body was closely attached to the cell membrane. In the gelatinous state, the oil body was concentrated around many small vacuoles, in the matured stage, the endosperm cells were filled with oil bodies, and the number of oil bodies reached the highest number. The oil bodies in the endosperm cells were synthesized in the endoplasmic reticulum. During the gelatinous period of the endosperm cells, the smaller oil bodies had lower electron density when observed under the electron microscope, while the larger ones had a ring-shaped structure with lower electron density, and there were multiple lipid droplets with high electron density aggregated in the central part. In the solid state of the endosperm, the oil body matured into a spheroid with uniform size and electron density. During the shrinkage period of the seed, the number of oil bodies in the endosperm cells decreased along with a decrease in the electron density.

Fabrication and characterization of Pickering High Internal Phase Emulsions (HIPEs) stabilized by chitosan-caseinophosphopeptides nanocomplexes as oral delivery vehicles

Pickering High Internal Phase Emulsions (HIPEs) stabilized by food-grade particles have received considerable attention. In this work, we first demonstrated the use of chitosan-caseinophosphopeptides (CS-CPP) nanocomplexes as particulate emulsifiers to stabilize the interface of natural oils and water. For this purpose, we developed the CS-CPP nanocomplexes through electrostatic interactions and demonstrated their application in the formation of stable Pickering HIPEs. The microstructures, e.g., interfacial frameworks, of the CS-CPP nanocomplexes partition between the continuous phase and interfacial region, and the states of the droplets of Pickering HIPEs were visualized by confocal laser scanning microscopy (CLSM) and an optical microscope. The compressed droplets in Pickering HIPEs formed a percolating 3D-network framework that endowed emulsions with viscoelastic, self-supporting, and ideal thixotropic features. In addition, the gelatinous state of Pickering HIPEs combined with robust and compact CS-CPP nanocomplexes formed an interfacial layer around the droplets, thus depressing the oxidation of linseed oil. The contents of primary and secondary oxidation products in HIPEs were lower than that in bulk oil and emulsions stabilized by surfactants. An in vitro gastrointestinal (GI) model was constructed to characterize the lipid oxidation, lipid digestion and curcumin bioaccessibility of Pickering HIPEs. Interestingly, this route enhanced the bioaccessibility of curcumin from 20.49% (bulk oil) to 49.21% (Pickering HIPEs). This work offers a facile method to develop Pickering HIPEs by food-grade particles, which help to fill the gap between the performance of CS-CPP nanocomplexes-stabilized Pickering HIPEs and potential applications as oral delivery systems of nutraceuticals.

The mechanism of salt effects on starch gelatinization from a statistical thermodynamic perspective

Understanding the gelatinization of starch requires a theoretical framework that can extract microscopic information from the literature's abundant experimental data in a quantitative manner. Recent developments in statistical thermodynamics have been adapted here to extract the starch-water and starch-salt affinity changes that occur during gelatinization, in a manner beyond the capabilities of traditional polymer theory. We have clarified the mechanism that leads to the increases of salt binding upon gelatinization at high concentrations. Contrary to previous assumptions, salt-starch affinity has been shown to be predominant in the salt effect on gelatinization over water structure contributions. How the temperature of gelatinization depends on salt concentration can be rationalized by the exclusion of salts at low salt concentrations from the gelatinized state and salt anion accessibility to the inside of the starch granule at increased concentration. Finally, the salt anion accessibility informs whether gelatinization progresses from the hilum or the periphery of the starch granule.

Fermentation of Corn Starch Powder for the Production of “Ogi”

Ogi was produced by fermenting corn starch powder for 24h and 48h using a seed culture (omidium) as a starter culture. Physicochemical properties such as pH, titratable acidity, viscosity, swelling power solubility, and proximate composition were determined. The sensory properties of the ogi produced was also determined and compared with ogi produced from the traditional method. The results of the proximate analysis showed that the carbohydrate content of sample B(fermented corn starch for 24h) is 78.47% and sample C(fermented corn starch for 48h) is 77.43% were significantly higher (p&amp;lt;0.05) when compared to the traditional method-sample A(73.43%).Protein content (10.63%) and fat content (5.10%) of sample A were significantly higher (p£0.05) than sample B (9.5%) (1.0%) and sample C (9.86%) (1.70%) respectively. The pH of ogi decreased from 5.18 at the beginning of the fermentation to 3.60 at the end of 48h. Whereas the titratable acidity increased from 0.27% to 0.63% after 48h of fermentation. The viscosity of the ogi in the gelatinized state increased as the fermentation period increased from 24h to 48h. There was ignificant (p³0.05) difference in color, flavor, aroma, taste, sourness, mouth feel and overall acceptability between sample A, C and B. The pH, titratable acidity, textural and sensory properties of ogi produced from corn starch powder that was fermented for 48h were more acceptable than ogi produced through the traditional method and from corn starch powder that was fermented for 24h.

Effect of Acid Methanol Treatment and Heat Moisture Treatment on In Vitro Digestibility and Estimated Glycemic Index of Raw and Gelatinized Sago (Metroxylon Sagu) Starch

This study aims to elucidate the effect of dual modification of acid methanol treatment (AMT) and heat moisture treatment (HMT) on digestibility and glycemic index (eGI) of sago starch in the raw and gelatinized state. AMT is conducted (1 and 2 mL of hydrochloric acid) prior to HMT (15 and 20% moisture content). Thermal behavior, pasting properties, morphology, and relative crystallinity of raw starches are investigated. Dual modification is found to significantly increase the resistant starch (RS) content in sago starch. Part of the RS is also found to be heat stable and able to survive the gelatinization. Starch with a higher RS fraction in raw form displays lower eGI. However, such a trend is not observed after gelatinization. Starch fractions and eGI are correlated in raw starch but not in gelatinized starch. Dual modification increases gelatinization temperatures but severely reduces pasting viscosities and causes granular surface erosion.

Effects of vacuum and ageing on Zr4/Cr3 based conversion coatings on aluminium alloys

In this study, we investigate the impact of ageing and high vacuum on existing environmentally friendly Zr4/Cr3-based conversion coatings. The freshly formed coating undergoes several changes during ageing and exposure to high vacuum. Based on the present data, we propose that the coating formed over AA6082 and AA7075 alloys is sol-gel in nature, confirmed by secondary neutral mass spectroscopy (SNMS) using the depth profiling technique. Our findings reveal that there are elemental level changes that result in shrinkage of the coating. Most Zr ions in the coating are in the solute form, with lesser number of Cr and Al ions that disappear under high vacuum over a certain period of time. The remaining Cr, Zr and O atoms exist in a gelatinous state. During ageing, there is a continuous transition of ions from solute to gelatinous state. In addition, the deposition of coating ions is directly influenced by the substrates and their constituents. The extent of dissolution of aluminium in the conversion bath determines both Zr and Cr ion deposition. For a highly alloyed metal like AA7075, the dissolution rate is disturbed by copper and zinc.

Communication—Gelatinization of Guar Gum and Its Effects on the Dispersion and Electrochemistry of Lithium-Sulfur Batteries

The effect of gelatinization and retrogradation of the popular binder, guar gum, on the dispersion of electrode constituents and the cell performance of the lithium-sulfur battery is studied. When guar gum is added in a gelatinized state, the fabricated electrode slurry adopts a gel-like structure, leading to the poor dispersion of constituents and poor electrochemistry of constructed cells. With the addition of retrograded guar gum, the prepared slurry is not gelled, and the dispersion of constituents and the cell performance are both greatly improved.

A simply enzymatic hydrolysis pretreatment for β-mannanase production from konjac powder

Currently, the traditional fermentation using konjac powder for β-mannanase production presents operational difficulties and high energy consumption, because of the individual hot air sterilization for konjac powder. A simply enzymatic hydrolysis pretreatment for konjac powder was developed to solve the problems of the traditional process in a 7-L fermenter. In the new process, when hydrolysis yield of konjac powder was above 50%, the media became liquid state from gelatinous state and could be sterilized immediately, avoiding the hot air sterilization and solving the operational difficulties. Interestingly, the new process didn’t have negative influence on β-mannanase production. Additionally, it could save close to 23% of power consumption during the whole fermentation. For another example, it did work well using locust bean gum for β-mannanase production in a 7-L fermenter. Therefore, the new process might be scaled up for industrial production using mannan-based bioresource as substrate.

Superparamagnetic IPN gels of carrageenan/PHEMA excelling in shape retention

Iron oxide nanoparticles-incorporated carrageenan (CAR)/PHEMA composites of interpenetrating network (IPN) type were successfully prepared by in situ ferrite synthesis in the polymer network. The IPN structure was constructed at CAR/PHEMA compositions of 15/85 and 40/60 (wt/wt) by polymerization and cross-linking of 2-hydroxyethylmethacrylate as an impregnating solvent of CAR gels. As a result of this IPN construction, the composites were firm and showed a good shape-retentivity in their gelatinous state. SQUID magnetometry and X-ray diffractometry were conducted for evaluation of the magnetic property of the inorganic-hybridized IPN composites. Magnetite particles with 10–30nm sizes were distributed inside the IPNs treated with the repeatable ferrite synthesis; thereby, the hybrids displayed a superparamagnetic character at ambient temperature. Specifically, the 40/60 CAR/PHEMA IPN imparted a practically passable value (10–15emu (g sample)−1) of saturation magnetization. The present IPN system offers a potential for application as a biocompatible magnetic material used in hydro-surroundings.

Changes in color and texture of wheat noodles during chilled storage.

Wheat noodles cooked for different periods of time were stored at 5°C, and color changes in their cross sections were quantitatively assessed by digital image analysis. The color of noodles with flattened moisture distributions whitened greatly during the early stages of chilled storage due to the retrogradation of starch, with the color change showing a significant correlation with the changes in noodle fragility. Color changes were also measured for wheat noodles and noodles containing modified starch with internal moisture distributions, and local changes within the noodles were kinetically analyzed. The addition of modified starch significantly reduced the color change in the noodle interior, where the moisture content was relatively low. Scanning calorimetric measurements indicated differences in the gelatinized state of modified starch and original wheat starch at low moisture contents, which affected the rate of color change in the interior of noodles containing modified starch.

High‐pressure homogenization induced degradation of amylopectin in a gelatinized state

An investigation of the degradation mechanism of a highly branched polymer during a high‐pressure homogenization (HPH) process was performed using gelatinized waxy maize starch as a substrate. The degradation mechanism was studied using high‐performance size‐exclusion chromatography equipped with multi‐angle laser‐light scattering and refractive index detectors. The HPH induced an exponential molecular degradation trend that was a function of HPH pressure/cycles. The results revealed that HPH preferentially disrupted larger molecules and caused their size distribution (or molecular weight) to a narrow range, resulting in a maximum stable size (or molecular weight). A final z‐average radius of gyration of about 20 nm for amylopectin was observed after HPH for eight cycles at 100 MPa or two cycles at 150 MPa, which was due to the midpoint scission mechanism during the HPH treatment. The increase in molecular density after HPH verified the breakdown of the α‐1,4‐glycosidic bonds among the clusters of (midpoint scission) amylopectin.