Stable Network Structure Research Articles

Effects of Transglutaminase Concentration and Drying Method on Encapsulation of Lactobacillus plantarum in Gelatin-Based Hydrogel.

Lactobacillus plantarum is a kind of probiotic that benefits the host by regulating the gut microbiota, but it is easily damaged when passing through the gastrointestinal tract, hindering its ability to reach the destination and reducing its utilization value. Encapsulation is a promising strategy for solving this problem. In this study, transglutaminase (TGase)-crosslinked gelatin (GE)/sodium hexametaphosphate (SHMP) hydrogels were used to encapsulate L. plantarum. The effects of TGase concentration and drying method on the physiochemical properties of the hydrogels were determined. The results showed that at a TGase concentration of 9 U/gGE, the hardness, chewiness, energy storage modulus, and apparent viscosity of the hydrogel encapsulation system were maximized. This concentration produced more high-energy isopeptide bonds, strengthening the interactions between molecules, forming a more stable three-dimensional network structure. The survival rate under the simulated gastrointestinal conditions and storage stability of L. plantarum were improved at this concentration. The thermal stability of the encapsulation system dried via microwave vacuum freeze drying (MFD) was slightly higher than that when dried via freeze drying (FD). The gel structure was more stable, and the activity of L. plantarum decreased more slowly during the storage period when dried using MFD. This research provides a theoretical basis for the development of encapsulation technology of probiotics.

Molecularly designed nonionic hydrophobic association polymers with anti-salt capacity: Enhancing drag reduction at high mineralization levels

The development of advanced anti-salt drag reduction (DR) agents is crucial for enhancing oil recovery rates, particularly in highly mineralized saline water where the network structure of polymers is prone to disruption, resulting in decreased DR. To address this problem, by carefully designing the structure of the hydrophobic association polymer, a new hydrophobic monomer called APO-10 was introduced, which successfully integrated water-soluble groups, and greatly enhanced the polymer's association properties in an aqueous solution. This ingenious approach produced a stable and robust network structure that can effectively resist the harmful effects of salt ions. PAPO-10 was synthesized through free radical polymerization and has hydrophilic EO chains that enhance its water solubility, enabling better extension of the hydrophobic long chain on the tail in solution. This facilitates the association between molecular chains, leading to the formation of a stable network structure even at low concentrations. PAPO-10 demonstrates remarkable properties, including rapid dissolution and exceptional resistance to salt. It delivers a remarkable DR of up to 78.2466 % at a concentration of 500 mg/L, dissolving within a mere 2 min in aqueous solutions. Molecular dynamics simulations confirmed that PAPO-10 exhibits strong polymer chain binding in solution, consistent with experimental results. Overall, this study provides valuable insights into the development of anti-salt polymers in slick fracturing.

Wettability, adhesive performance and structural evolution of an environment-friendly modified silicate binder for foundry moulding and coremaking

For the manufacturing of sand cores, silicate inorganic binders have emerged as promising green casting binder materials; however, their adhesive performance requires further improvement. In this study, to evaluate the impact of using water-soluble polyols, i.e. polyethylene glycol (PEG) and xylitol, to modify silicate adhesives, the effect of the content and type of water-soluble polyol on the colloidal stability, wettability and adhesive performance of a silicate binder were investigated. The structural evolution of the modified silicate binder and the polysilicate bondswere studied using characterisation techniques including infrared spectroscopy and 29Si nuclear magnetic resonance (NMR) spectroscopy. Results revealed that PEG 400 and PEG 600 increased the size of polysilicate particles in the solution, resulting in flocculation of the silicate binders and easy precipitation or separation in a short period of time. However, PEG 200 and xylitol exerted little effect on the stability of the silicate solution. Moreover, 0.25 wt% PEG 200 reduced the surface tension of the solution from 78.93 to 54.15 mN/m and the equilibrium contact angle from 45.0° to 34.6°. The polyol promoted the dehydration and condensation of silicic acid gel to form a more stable three-dimensional network structure, improving the bonding strength of casting sand cores prepared using the silicate binder and silica sand from 2.42 to 3.02 MPa. This study not only unveils the role of PEG in improving the wettability and bonding behaviour but also provides an example of the rational use of environment-friendly water-soluble polyols to enhance the performance of green inorganic adhesive materials.

Construction of soybean oil bodies–xanthan gum composite oleogels by emulsion-templated method: Preparation, characterization, and stability analysis

Oil bodies (OBs), a special tissue that stores oil in plant cells, are rich in polyunsaturated fatty acid, vitamin E, phytosterols, and other functional components. In this study, different concentrations of xanthan gum (XG)-stabilized OBs were prepared using the electrostatic deposition technique, and oleogels were prepared via freeze-drying and shearing effects. The relationships between the properties of OB emulsions (OBEs), intermediate products (freeze-dried samples), and end products (oleogels) were explored. The XG addition significantly enhanced the stability of OBs. Particularly, when it achieved 1.5%, the average particle size of OBEs was the least at 892.03 nm, the ζ-potential absolute value was greater than 30 mV, and the porosity was a minimum of approximately 3.68%. Freeze-dried samples with XG had less oil on their surfaces, and their hardness and springiness were significantly and positively correlated with XG addition. The excellent stability of the OBEs and freeze-dried samples resulted in the formation of a dense and stable three-dimensional network structure to hold the oil. The oil holding capacity, rheological properties (including higher yield stress, stronger elastic, and thixotropy behavior), and thermal stability of the oleogels improved with increasing XG addition. Moreover, the compact networks and excellent oil holding capacity of the OB-based oleogels with XG effectively hindered high-temperature destruction and oil oxidation. The correlation analysis and the scheme model indicated that the oleogel properties could be traced back to the interaction effects among the OB components. These results provide guidance for the design and quality control of OB-based oleogels.

Effect of konjac glucomannan with different degrees of deacetylation on the gel behavior of transglutaminase induced soybean protein isolate emulsion gels

In this study, the effect of konjac glucomannan (KGM) with different degrees of deacetylation (DD) on the gel properties of transglutaminase induced soybean protein isolate (SPI) emulsion gel was investigated. It was found that the three kinds of KGM increased the breaking force and water holding capacity, enhanced the freeze-thaw stability of the SPI emulsion gel, while KGM with DD of 59% (DKGM1) improved these properties to the largest extent. This was because SPI-DKGM1 had the lowest oil water interfacial tension, resulting in the formation of the most uniform and the smallest oil droplets, which then led to the formation of much denser gel network. Moreover, the hydrophobic interaction and hydrogen bonding between DKGM1 and SPI were the strongest compared with that of other KGM. Besides, FTIR results showed that SPI-DKGM1 emulsion gel had higher β-sheet content, which was conductive to the formation of a stable three-dimensional network structure. However, the combination of SPI and KGM with high DD (DKGM2, DD = 92%) destroyed the gel structure to some extent and resulted in emulsion gel with weakened gel properties compared with that of DKGM1. Therefore, KGM with proper DD was conducive to the formation of more ordered and much denser gel network structure, which then resulted in SPI emulsion gel with the best gel properties.

Temperature and pH-dependent nanogel for smart pesticide delivery with enhanced foliar dispersion and washout resistance can effectively control multiple plant diseases

The utilization of nanomaterials to develop a system capable of regulating pesticide release in response to environmental cues, enhancing the deposition efficacy on plant leaves, and increasing resistance against rainwater erosion holds immense significance in improving the efficiency of pesticide usage while minimizing residual pollution. Cellulose-based green nanocomposites have emerged as a promising candidate for intelligent drug delivery systems. In this study, we had successfully developed a novel biocompatible interpenetrating polymer network (IPN) gel, named SPCs, by incorporating sodium alginate (SA), polydopamine (PDA), and cellulose nanocrystal (CNC), and a stable gel-like network structure emulsion (MJ@SPCs) was achieved by coating the pesticide azoxystrobin (MJ). The resulting MJ@SPCs exhibited excellent pH responsiveness and temperature sensitivity. Compared to free MJ, MJ@SPCs exhibited improved foliar wettability, rain erosion resistance, deposition rate, and controlled release performance. The results of the bacteriostatic performance test indicated that MJ@SPCs exhibited a higher inhibitory efficiency against Gibperella zeae (GZ) than MJ at equivalent concentrations. Moreover, the in vivo biosafety evaluation of MJ@SPCs had confirmed its relative safety for aquatic zebrafish. This study offers insights into the potential applications of nanopesticides for sustainable plant protection.

Li2O–V2O5–MoO3–Fe2O3 amorphous cathode material for lithium-ion batteries based on coordinated multi-electron effect and stable network structure

The amorphous cathode materials Li2O–V2O5–MoO3 and Li2O–V2O5–MoO3–Fe2O3 were produced via melt quenching. By analyzing the structure, elemental valence, and electrochemical characteristics of Li2O–V2O5–MoO3 at different ratios, the effects of MoO3 addition on vanadium-based amorphous cathode materials were explored. 20Li2O–60V2O5–20MoO3 has a high initial capacity (268.0 mAh/g for the first reversible discharge at a current density of 50 mA/g), which is based on the properties that MoO3 supplies additional oxidation reductions and has [MoO6] structural units to widen the diffusion channels for lithium ions in the network structure. Unfortunately, the network of the structural elements [MoO6] and [VO4] is unstable, which causes the material to have poor cycle stability and exhibit an unsatisfactory current response. The network structure stability of Li2O–V2O5–MoO3–Fe2O3 is increased by adding Fe2O3 to provide [FeO4], which strengthens the link between each structural unit. Vanadium oxidation reductions are promoted, and iron oxidation reductions replace the role of molybdenum in the charge/discharge. The discharge product transforms from LiVMoO5 to Li2FeV3O8 with increased de-embedding Li efficiency. The 20Li2O–60V2O5–10MoO3–10Fe2O3 achieves an initial reversible specific capacity of 255.2 mAh/g at 50 mA/g, 139.7 mAh/g additional specific capacity after 100 cycles, and 110.5 mAh/g specific capacity at a high current density of 400 mA/g. The test findings show that 20Li2O–60V2O5–10MoO3–10Fe2O3 efficiently increases high-current responsiveness and cycle stability while retaining a high capacity. In this study, we propose a compositional design strategy, which is based on the coordinated multi-electronic effect of multiple transition metal elements and the design of a stable disordered network structure, to incorporate MoO3 and Fe2O3 into vanadium-based amorphous to create a novel cathode material. This work offers a fresh perspective on investigating innovative lithium-ion battery cathode materials.

Bacterial diversity of herbal rhizospheric soils in Ordos desert steppes under different degradation gradients

Objectives This study explored the effects of different degradation gradients on bacterial diversity in the rhizospheric soils of herb plants. Methods The alpha diversity, species composition and correlations of bacterial communities in the rhizospheric soils of herb plants were studied using metagenomics 16SrDNA gene high-throughput sequencing. Results The diversity of bacterial communities in the rhizospheric soils of herb plants differed during the degradation of desert steppes. An analysis of bacterial community alpha diversity indices showed the bacterial diversity and species evenness of rhizospheric soils were best in moderately degraded desert steppes. Among all samples, a total of 43 phyla, 133 classes, 261 orders, 421 families, 802 genera and 1,129 species were detected. At the phylum level, the predominant bacterial phyla were: Actinobacteria, Proteobacteria, Acidobacteria, Gemmatimonadetes, Chloroflexi, Planctomycetes and Bacteroidetes. At the genus level, the predominant bacterial genera were: RB41, Sphingomonas, WD2101_soil_group_unclassified, Pseudomonas and Actinomyces. The relative abundance of unknown genera was very large, which deserves further research. At the phylum and genus levels, the species abundance levels under slight and moderate degradation were significantly higher than those under extreme degradation. Correlation network diagrams showed there were many nodes in both slightly deteriorated and moderately deteriorated soils, and the node proportions were large and mostly positively correlated. These results indicate the bacterial communities in rhizospheric soils under slight or moderate deterioration are relatively stable. The rhizospheric soil microbes of desert steppes can form a stable network structure, allowing them to adequately respond to environmental conditions. Conclusions The bacterial communities in the rhizospheric soils of herb plants differ between different degradation gradients. The species number, abundance and diversity of bacterial communities in rhizospheric soils are not directly correlated with degree of degradation. The abundance, species diversity and species abundance of bacterial communities in the rhizospheric soils of moderately degraded desert steppes are the highest and most stable. The soil bacterial diversity is lowest in severely degraded desert steppes.

Curing properties study on sucrose-melamine-formaldehyde resin

Melamine formaldehyde resin (MF) has a long history of about 90 years since its birth. Its industrial application, however, has been limited by the high cost of raw materials, high content of free formaldehyde and easy cracking of adhesive layer after curing. These problems can be solved by making use of biomass resources to modify MF in theory. Sucrose, melamine and formaldehyde were noted as the main raw materials for synthesizing sucrose-melamine-formaldehyde copolymer resin (SMF) under alkaline conditions. The effect of sucrose content and curing agent on the curing properties have been carried out through Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance spectrum (NMR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The findings show that the SMF curing behavior was an exothermic process, which was achieved by the dehydration synthesis between hydroxymethyl groups. The sucrose content had a large effect on the thermal stability and the curing behavior of SMF, and the addition of curing agent promoted the resin curing. Not only was the thermal stability decreased, but also the curing reaction was more difficult to occur with the sucrose addition. The sucrose molecules participated in the curing process through chemical bonding, and then formed a stable network structure for the resin system.

Analysis of nanoscale evolution features of microstructure of asphalt based on atomic force microscopy

To reveal the microstructural evolution of asphalt at the nanoscale, this study utilizes an atomic force microscope (AFM) to observe the surface morphology of asphalt and employs roughness theory for its quantitative assessment. The effects of asphalt type, aging state, immersion time, chloride salt concentration, and modifiers on beelike structures and roughness were comprehensively considered. The results demonstrated that the area and number of beelike structures, as well as the roughness, varied with different asphalt types. After aging, the surface morphology of the asphalt became rougher, leading to an increase in surface roughness, while both the number and area of the beelike structures in the asphalt showed a decreasing trend. With increasing immersion time, water penetrated into the asphalt and interacted with its components, disrupting the colloidal structure under dry conditions and causing microstructural damage and peeling. Consequently, distinct nanoscale protrusions and white spots appeared on the asphalt surface. Moreover, the total area of beelike structures decreased, and the roughness parameters increased with an increase in chloride salt concentration. Compared to matrix asphalt, the beelike structures in crumb rubber (CR) modified asphalt disperse into finer, speckled black-and-white patterns. The styrene–butadiene–styrene (SBS) modifier forms a stable three-dimensional spatial network structure within the asphalt, diminishing the difference between beelike and non-beelike structures. In the original state, the average roughness (Ra) and root mean square roughness (Rq) of PJ90/CR are 63.0% and 74.0% lower than those of PJ90, respectively. Meanwhile, the Ra and Rq of PJ90/SBS are 42.7% and 46.9% lower than those of PJ90, respectively.

Mechanism on the Synergistic Gelation of the Myofibrillar Protein Composite Gel Enhanced by "Clean-Label" Skin Functional Protein Powders.

The concept of healthiness and sustainability has promoted the innovation and development of "clean-label" products. Herein, this study aims to explore the influence mechanism of "clean label" skin protein powder (FPP) on the gelation properties of myofibrillar proteins (MPs). Specifically, the addition of FPP (0.2-4.0%) can improve the water holding capability and texture properties of MP composite gels. When the FPP concentration is over 1.0%, the composite gels exhibit no significant water loss during centrifugation. Dynamic rheology and sodium-dodecyl sulfate-polyacrylamide gel electrophoresis results revealed that FPP can slow the aggregation and denaturation of myosin and promote the formation of disulfide bonds between myofibril proteins, thus forming a stable network structure. Structural observation revealed that FPP can fill into the MP gel and lead to the formation of compact gel structures. Besides, with the increase of FPP concentration, the chemical forces involved in structural stabilization change significantly. Specifically, hydrophobic interaction and hydrogen bonding are the dominant forces at a lower FPP concentration (0.2 and 0.4%), while the ionic bond and disulfide bond are the dominant forces at a higher concentration. Overall, this work demonstrated that FPP can significantly improve the gel functionality of MP by altering the gel structure and strengthening the molecular forces.

The role of lipids in determining the gas cell structure of gluten-free steamed oat cake

The stabilization of gas cells is crucial to obtain cake or bread products with a homogeneous crumb and is mainly depends on the proteins, starches, and lipids. Oats, in particular, are known for their high lipid content compared to other grains. However, the specific contribution of oat lipids to the gas chamber structure in gluten-free steamed oat cake is still unclear. Hence, to elucidate the potential mechanism involved, this study aimed to investigate the steaming characteristics of oat dough, as well as the protein-starch network matrix (including protein aggregation and structural properties), and the air/water interfacial characteristics (including foaming and surface tension properties) of oat dough liquor subjected to different defatting treatments. Results showed that by moderately removing lipids from samples (particularly ROF-D3 with 2.91% lipid content), gas retention ability, cell area fraction, and specific volume of the steamed oat cake were enhanced, which were 93.30 mL/100 mL, 36.27%, and 2.72 mL/g, respectively. Weak protein aggregation and an ordered protein secondary structure corresponding to a more open and stable protein network structure were observed in the ROF-D3 sample caused by moderate lipid removal. In addition, moderate removal of lipids obviously increased the extraction yield of oat dough liquor, in which lipid was evidently the dominant component. Compared to the ROF-D1 sample, the enhanced quality of the ROF-D3 sample can be attributed to the strongest foam stability and the increased air-water interface surface tension.

Engineering pH responsive carboxyethyl chitosan and oxidized pectin -based hydrogels with self-healing, biodegradable and antibacterial properties for wound healing

As an important organ of the human body, effective protection of the skin during trauma is crucial. An ideal wound dressing should have adhesion, adsorption of wound secretions, and good antibacterial properties. Two kinds of natural polysaccharide-based hydrogels, carboxyethyl chitosan/oxidized pectin hydrogel (CEC/OP) and carboxyethyl chitosan/oxidized pectin/polyethyleneimine hydrogel (CEC/OP/PEI), were reported by using carboxyethyl chitosan as the matrix, and oxidized pectin and branched polyethyleneimine as the crosslinking agents. Both hydrogels could be formed in a short time and exhibited the pH responsively due to the presence of imine bond. Compared with carboxyethyl chitosan/oxidized pectin hydrogel, polyethyleneimine containing hydrogel can form gel quickly, a more compact and stable three-dimensional space network structure was formed, which exhibited better swelling performance, the swelling ration, rheology property, self-repair ability, and antibacterial performance. When the mass fractions of carboxyethyl chitosan and oxidized pectin solutions are 4 wt% and 9 wt%, respectively, the hydrogel exhibited an antibacterial efficiency of >96 % against both Staphylococcus aureus and Escherichia coli. After adding 0.75 wt% polyethyleneimine, the antibacterial efficiency of hydrogel could reach up to >98 %. More importantly, the polyethyleneimine containing hydrogel has a significant effect in the treatment of bacterially infected wounds.

Characterization of the physiochemical properties, microstructure, and molecular interactions of a novel rice-pea protein gel.

The application of rice and pea proteins in food production is limited due to their undesirable processing performance. The objective of this research was to develop a novel rice-pea protein gel using alkali-heat treatment. This gel had a higher solubility, stronger gel strength, better water retention capacity, and denser bilayer network. This is due to the alkali-heat induced modifications for the secondary structures of proteins (i.e., a decrease in the α-helix, and an increase in the β-sheets) and the interactions between protein molecules. The network structure of gel was more compact by adding 2% and 4% alkali-heat rice protein (AH-RP). This resulted in a stable double-layer network structure of gel. Adding 4% AH-RP significantly improved the hardness and elasticity of gel. This gel will have a good potential use for being the ingredient to produce the functional foods and meat analogs.

Zinc Hydroxystannate/Carbon Nanotube Hybrids as Flame Retardant and Smoke Suppressant for Epoxy Resins.

Novel hybrid flame retardants containing zinc hydroxystannate and carbon nanotubes (ZHS-CNTs) were synthesized using the coprecipitation method, and the structure and morphology of ZHS-CNTs were investigate using an X-ray powder diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and thermogravimetric analyzer (TGA). Then, the ZHS, CNTs and ZHS-CNTs were incorporated into EP, respectively, and the flame-retardant and smoke inhibition performance of the composites were compared and studied. Among the three composites, the EP/ZHS-CNT composites have the highest improvements on the fire resistance and smoke inhibition properties. With only 2.0 wt.% ZHS-CNT hybrids, the pHRR of EP/ZHS-CNT composite materials is reduced by 34.2% compared with EP. Moreover, the release of toxic gases including CO, CO2 and SPR from the composites was also effectively inhibited. The mechanisms of flame retardant and smoke inhibition were investigated and the improved properties were generally ascribed to the synergistic flame-retardant effects between ZHS and CNTs, the catalyzing effect of ZHS and the stable network structure of CNTs.

Improving the Anti-washout Property of Acrylate Grouting Material by Bentonite: Its Characterization, Improving Mechanism, and Practical Application.

Acrylate is a popular polymer grouting material that has been widely used to control groundwater seepage. However, the vulnerability of acrylate slurry to dynamic water washout restricts its application in groundwater environments characterized by high flow velocity and water pressures. In this paper, lithium bentonite (Li-B) was used to modify the traditional magnesium acrylate (AC) grouting material. The influence of Li-B to AC ratios on the modified materials' washout resistance was explored, and the modification mechanism was analyzed using X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). Finally, the anti-washout ability of the modified slurry was verified through engineering applications. Results revealed that LiB-AC grout had adjustable setting times (10.5 to 395.6 s), minimal bleeding (0.1%), higher viscosity (65 mPa·s) and expansibility (350%), stronger anti-water dispersibility (24 times that of pure AC slurry), higher mechanical strength (compressive strength is 0.386 MPa, tensile strength is 0.088 MPa), and better impermeability (2.23 × 10-8 m/s). The lithium bentonite was beneficial to the setting time, bleeding, viscosity, slurry retention rate, impermeability, and mechanical strength of the acrylate grout. However, it diminished the expansibility of the acrylate grout. At the optimal acrylate content (20%), the mechanical strength and impermeability of the LiB-AC grout were the highest. The better performance of LiB-AC grout was attributed to the formation of a more stable and dense interlaced spatial network structure after the modification by Li-B. The LiB-AC grout was used in the dynamic water grouting project of a metro shield tunnel segment and achieved better anti-washout performance than cement-water glass and pure AC slurry.

Research on 3D network in-situ grown NiCo2O4 nanowire arrays construction and its energy storage performance

In this paper, NiCo2O4 nanowire arrays are synthesized on 3D NF skeleton by a one-step hydrothermal method and used as anode materials for lithium-ion batteries (LIBs). Dense nanowire arrays are grown in situ on NF skeleton, cross-linked and constructed into 3D network structure. As an anode, it exhibits excellent electrochemical properties. The initial discharge capacity of NiCo2O4/NF is as high as 1316 mAh g−1 at a current density of 0.2 A g−1, and the specific capacity of 790 mAh g−1 can be maintained after 200 cycles. And NiCo2O4/NF can also maintain a specific capacity of 580.37 mAh g−1 at a current density of 1 A g−1 in the rating performance. And transfer resistance after 200 cycles reduced by 53.5%,which shows a tendency to decrease during the reaction process and accelerates the rate of Li+ transfer, improved battery cycling performance. The excellent lithium storage performance is attributed to the high aspect ratio of the nanowires themselves and the stable 3D network structure, which not only facilitates the rapid transfer of substances and diffusion of Li+, but also alleviates the volume change during the charge/discharge cycle. The band gap of NiCo2O4 can be obtained as 0.671 eV by first nature principle calculation, the electrons readily jump from the valence band to the conduction band and have good conductivity. And the diffusion potential barrier is 0.4 eV, which is easily overcome in the experiment and facilitates the transport of lithium ions.

Study on the mechanism of soy protein isolate to improve quality of reduced-salt Hypophthalmichthys molitrix surimi gel: Focus on gel quality, protein structure, and in vitro digestibility

Excessive intake of sodium chloride may bring a series of diseases; as a result, reduced-salt surimi gels have gained growing popularity for sodium reduction. This paper studied soy protein isolate (SPI, 2.0%, 4.0%, and 6.0%, w/w) as a gel enhancer for reduced-salt silver carp surimi. Compared with the control (2.0% NaCl), the addition of SPI significantly increased (P < 0.05) the total SH content, hydrophobic interaction force, disulfide bond, hardness, gel strength, and water-holding capacity of the gels. During the thermal denaturation process, SPI and myofibrillar protein jointly participated in the formation of the gel network, resulting in a G′ value increase at 90 °C, forming a denser/more stable gel network structure. In vitro pepsin digestion results showed the digestibility of the reduced-salt gel with SPI was higher than that of the control. Therefore, appropriate SPI addition can improve the gel performance of reduced-salt surimi gel without affecting digestion and absorption.

Regulation mechanism of ionic strength on the ultra-high freeze-thaw stability of myofibrillar protein microgel emulsions.

The regulation mechanism of ionic strength (0-1000mM) on the freeze-thaw (FT) stability of emulsions stabilized by myofibrillar protein microgel particles (MMP) was systematically investigated. High ionic strength emulsions (300-1000mM) exhibited stability after five FT cycles. With ionic strength increasing, the repulsive force between particles gradually reduced, the flocculation degree (20.72∼75.60%) and apparent viscosity of emulsions gradually rose (69∼170mPa·s), promoting the formation of protein network structures in the continuous phase. Concurrently, the interfacial proteins rearranged (18.8∼104.2s-1) and aggregated rapidly, facilitating the formation of a stable interface network structure, ultimately improving its stability. Besides, scanning electron microscopy (SEM) images revealed that the interfacial proteins gradually aggregated, further forming a network with the MMP in the continuous phase, allowing MMP emulsions with enhanced FT stability at high ionic strength (300-1000mM). This study was beneficial to produce emulsion-based sauces with ultra-high FT stability.

Improved gelling and emulsifying properties of chicken wooden breast myofibrillar protein by high-intensity ultrasound combination with pH-shifting

The functional properties of chicken wooden breast myofibrillar protein (WBMP) are impaired. The protein structure and functional properties of WBMP are investigated using high-intensity ultrasound (HIU, 20 kHz, 200, 400, 600, and 800 W) combined with pH-shifting. HIU promoted the unfolding of WBMP, reduced the particle size of WBMP, and enhanced electrostatic repulsion. Medium-power (200 and 400 W) HIU promoted the α-helix to β-sheet transformation, while high-power (600 and 800 W) HIU significantly (P < 0.05) increased the content of the random coil. The microstructure and images after storage further showed that 400 W HIU in combination with pH-shifting made the WBMP emulsion more uniform. In addition, gel performance analysis showed that the gel strength and water-holding capacity of the protein gel increased gradually after 400 W. Scanning electron microscope images also showed the formation of a stable network structure in the protein gel. This work could help promote the utilization of inferior proteins similar to WBMP, but the utilization rate still needs to be further improved.