Gel-forming Ability Research Articles

Polysaccharide-Based Fat Replacers in the Functional Food Products

The functional properties of food products, in addition to enrichment with functional components, can also be achieved by reducing the content of certain components such as sugars and fats, that is, by reducing the energy content of the product. Thus, the development of functional food products is aimed at various low-energy products, especially products with a reduced fat content, which normally represent the most concentrated source of energy. Fat replacers should simulate the functional properties of the fat. Polysaccharide-based fat replacers include a variety of native starches, modified starches, maltodextrins, cellulose and cellulose derivatives, polydextrose, inulin, pectin, other dietary fibers, and hydrocolloids. Technological properties required for the application of carbohydrate-based fat replacers are water-holding capacity, a certain level of viscosity, required form and particle size, three-dimensional networking and gel-forming ability, sensory abilities such as spreadability, softness, greasiness feeling in the mouth, and other fat-like properties. These fat replacers are usually applied in combinations with the aim of achieving all desired properties normally provided by fats in foods. In the contemporary literature, there are many examples of their application in different food products, including baked goods, meats, dairy products, and emulsion food systems, successfully reducing the fat content with or without minor alterations in the rheology or sensory features of food products. In summary, polysaccharides-based fat replacers offer an effective method for fat reduction in different food products along with enhancing the health benefits of reduced-fat foods.

Effect of Fiber Drink Consumption Containing Glucomannan and Isomaltooligosaccharide on Digesta Profile and Gut Microbiota

Dietary fibers have long been recognized for their numerous health benefits, including supporting gut health, aiding in weight management, and reducing the risk of cardiovascular disease. Glucomannan, derived from konjac and porang tubers, has gained attention for its diverse health-promoting properties. However, its application in beverages is limited due to its high viscosity. Combining glucomannan with isomaltooligosaccharide (IMO) is suggested to synergistically enhance functionality, particularly improving gastrointestinal health. This study investigates the functional effects of porang glucomannan and isomaltooligosaccharide-containing fiber drinks (GIFD) on body weight, feed intake, digesta profiles (digesta weight, moisture content, pH) and gut microbiota using in vivo method. Twenty-four male Sprague Dawley rats were divided into 4 groups, including control, inulin, and 2 doses of glucomannan and isomaltooligosaccharide fiber drink (GIFD). Rats were fed with AIN-93M. Adaptation was carried out for 5 days followed by 28 days of intervention. Results indicate that GIFD consumption led to reduced feed intake, likely due to increased satiety effects and glucomannan’s gel-forming ability, resulting in lower body weight gain compared to other groups. While GIFD did not significantly alter digesta weight and moisture contents, it significantly decreased pH values. Analysis of short-chain fatty acids (SCFAs) showed a shift in propionic acid levels, suggesting a beneficial effect on weight control. Moreover, GIFD treatment reduced abundance percentages of enteric bacteria like E. coli and Clostridium, possibly due to increased SCFA production. However, GIFD consumption did not significantly alter sIgA concentration, although there was a trend towards increased levels in GIFD-2, suggesting potential immunomodulatory effects. Overall, it was indicated that porang glucomannan and IMO-containing fiber drinks has the potential to be used as beverages to support body weight regulation and to help maintaining digestive tract health. HIGHLIGHTS Glucomannan and isomaltooligosaccharide-containing fiber drinks (GIFD) reduced feed intake. Consumption of GIFD induced the shift of molar proportion of SCFAs suggesting beneficial health effect. GIFD treated groups showed lower abundance percentages of coli and Clostridium compared to control. GIFD is potential to be developed as weight management product. GRAPHICAL ABSTRACT

Effect and mechanism of different exogenous biomolecules on the thermal-induced gel properties of surimi: A review.

Surimi products are favored by domestic and foreign consumers due to their distinctive gelatinous texture, rich nutrition, and convenient consumption. Gel properties are key evaluation indicators for the quality of surimi products, which was mainly determined by the gel-forming ability of the myofibrillar protein (MP). In recent years, the surimi processing industry has faced challenges in product quality that limits the further development, and how to effectively improve the gel properties of surimi products has become one of the key scientific problems to be solved in surimi processing industry. A viable strategy for improving the product quality involves combining surimi with exogenous additives, such as proteins, polysaccharides, and lipids, to enhance the gel-forming ability of MP. At present, there is limited literature review to systematically investigate the role of these exogenous additives in interacting with MPs in surimi gel system and their effect on the gel properties of heat-induced surimi. Therefore, in this review, we systematically discussed the formation mechanism and influencing factors of surimi gel, the interactions of exogenous biomolecules (proteins, polysaccharides, and lipids) with surimi protein, as well as their effects on the gel properties of surimi product. The aim of this review was to help us with a better understanding for the intrinsic action mechanisms of complex surimi system and provide some theoretical guidance for the improvement of gel quality and development of surimi products.

Chitosan-Clay Mineral Nanocomposites with Antibacterial Activity for Biomedical Application: Advantages and Future Perspectives.

Polymers of natural origin, such as representatives of various polysaccharides (e.g., cellulose, dextran, hyaluronic acid, gellan gum, etc.), and their derivatives, have a long tradition in biomedical applications. Among them, the use of chitosan as a safe, biocompatible, and environmentally friendly heteropolysaccharide has been particularly intensively researched over the last two decades. The potential of using chitosan for medical purposes is reflected in its unique cationic nature, viscosity-increasing and gel-forming ability, non-toxicity in living cells, antimicrobial activity, mucoadhesiveness, biodegradability, as well as the possibility of chemical modification. The intuitive use of clay minerals in the treatment of superficial wounds has been known in traditional medicine for thousands of years. To improve efficacy and overcome the ubiquitous bacterial resistance, the beneficial properties of chitosan have been utilized for the preparation of chitosan-clay mineral bionanocomposites. The focus of this review is on composites containing chitosan with montmorillonite and halloysite as representatives of clay minerals. This review highlights the antibacterial efficacy of chitosan-clay mineral bionanocomposites in drug delivery and in the treatment of topical skin infections and wound healing. Finally, an overview of the preparation, characterization, and possible future perspectives related to the use of these advancing composites for biomedical applications is presented.

Tailoring highland barley bran arabinoxylans: Insights into composition, structure, and functional properties

Highland barley bran (HBB) stands as an underutilized source of arabinoxylans (AXs), presenting promising prospects for various applications. This study focuses on the isolation of four different AXs (S20, S40, S60, S80) from HBB using alkali extraction and gradient alcohol precipitation. These AXs exhibited diverse purity (56.47%–80.92%), monosaccharide compositions (A/X:0.47–0.96), and molecular weights (Mw) (173.5–498.2 kDa) of different AXs, along with different microstructural variations, amorphous qualities, and thermal stability. Rheological analyses demonstrated their shear-thinning behavior and distinctive gel-forming capacities, with S20 exhibiting superior viscosity and gel-forming ability. Notably, all four AXs demonstrate notable DPPH and ABTS radical scavenging capacities, with S80 demonstrating the highest antioxidant potency. Correlation analyses highlighted connections between molecular weight, branching degree, and rheological and antioxidant properties of AXs. Among different AXs, S20, with its low branching degree (0.47) and high molecular weight (390.4 kDa), exhibited significant viscosity, suggesting its suitability as a natural thickener in food processing. Conversely, S80, characterized by its low molecular weight (173.5 kDa), high branching degree (0.96), and potent antioxidant activity, holds promise as a natural antioxidant in functional foods. This study provides crucial insights for tailoring AX applications, unlocking the potential for the valorization of HBB in diverse scenarios.

Exploring marine-based compounds as cross-linkers to improve the biocompatibility and sustainability of chitosan-based hydrogels

Chitosan is one of the most promising natural polymers, its fundamental scientific research is growing uninterruptedly and has been applied in a wide and varied range of domains, including biomedical and water treatment applications. Therefore, the search and implementation of non-synthetic and non-toxic cross-linkers for chitosan-based hydrogels is crucial for the development of more sustainable and biocompatible materials. Herein, an alternative approach has been developed to explore and exploit methanolic and aqueous extracts from five red seaweed species as covalent cross-linkers for chitosan-based hydrogels. The formation of a gel could be denoted for all extracts, whereas the protein-rich methanolic extractions afforded instantaneous gel-forming ability and greater stiffness and stability. The obtained hydrogels present large porous system with high degrees of swelling up to ca. 3000 %, and were successfully applied as dye adsorbent to remove industrial dye methyl orange withing a circular process with adsorption capacities of 728.46 ± 66.17 mg/g. Furthermore, cytotoxicity and cell-adhesion studies revealed the biocompatibility of the hydrogels and their potential applicability for tissue-engineering. This work demonstrated that methanolic and aqueous extracts from different red seaweed species could replace toxic cross-linkers. Furthermore, the unexpected ability of some extracts could pave the way for the development of new formulations for additive manufacturing, in particular for 3D printing approaches.

Emulsions, dipsticks and membranes based on oxalic acid-treated nanocellulose for the detection of aqueous and gaseous HgCl2

Although cellulosic materials have been used as stabilizing agents for oil-in-water emulsions since the 1980s, their properties and the underlying mechanism are not universal regardless of the dispersed phase or of the treatments on cellulose. One case of unconventional organic phase is acetic acid-containing chloroform, which is known to be a good solvent system for the preservation of dithizone. In turn, dithizone is a long-known chromogenic reagent for the colorimetric detection of HgCl2. However, its usefulness is limited by its fast degradation in polar solvents. For instance, its dissolution in ethanol and the subsequent impregnation of paper strips allowed to quantify aqueous HgCl2 reliably and quickly (5.4 – 27 mg L–1), but only if they were used along the first 24 h after dip coating. Furthermore, those strips could not be used for sublimated HgCl2. The dithizone/chloroform-in-water emulsions presented in this work overcame these limitations. We opted for oxalic acid-treated cellulose nanofibers (ox-CNFs) as stabilizer, aiming at a proper balance between amphiphilic character and electrostatic repulsion. In this sense, ox-CNFs attained good gel-forming ability with a low content of carboxylate groups. The minimum ox-CNF concentration required was 0.35 wt%, regardless of the proportion of chloroform. This consistency implied yield stress values above 0.7 Pa. Nanocellulose also provided film-forming capabilities, which were exploited to produce visually responsive dipsticks and membranes. While quantification and reproducibility were hampered by the increase in the complexity of the system, dithizone/ox-CNF films were still a valid option for HgCl2 detection, outperforming solution coating in terms of stability, blank signal, and selectivity.

Arabinoxylan-based psyllium seed hydrocolloid: Single-step aqueous extraction and use in tissue engineering

Biomacromolecules derived from natural sources offer superior biocompatibility, biodegradability, and water-holding capacity, which make them promising scaffolds for tissue engineering. Psyllium seed has gained attention in biomedical applications recently due to its gel-forming ability, which is provided by its polysaccharide-rich content consisting mostly of arabinoxylan. This study focuses on the extraction and gelation of Psyllium seed hydrocolloid (PSH) in a single-step water-based protocol, and scaffold fabrication using freeze-drying method. After characterization of the scaffold, including morphological, mechanical, swelling, and protein adsorption analyses, 3D cell culture studies were done using NIH-3 T3 fibroblast cells on PSH scaffold, and cell viability was assessed using Live/Dead and Alamar Blue assays. Starting from day 1, high cell viability was obtained, and it reached 90 % at the end of 15-day culture period. Cellular morphology on PSH scaffold was monitored via SEM analysis; cellular aggregates then spheroid formation were observed throughout the study. Collagen Type-I and F-actin expressions were followed by immunostaining revealing a 9- and 10-fold increase during long-term culture. Overall, a single-step and non-toxic protocol was developed for extraction and gelation of PSH. Obtained results unveiled that PSH scaffold provided a favorable 3D microenvironment for cells, holding promise for further tissue engineering applications.

Physicochemical and antioxidant properties of pectin fractions extracted from lemon (Citrus Eureka) peels

Pectin, a natural polysaccharide, holds versatile applications in food and pharmaceuticals. However, there is a need for further exploration into extracting novel functional fractions and characterizing them thoroughly. In this study, a sequential extraction approach was used to obtain three distinct lemon pectin (LP) fractions from lemon peels (Citrus Eureka): LP extracted with sodium acetate (LP-SA), LP extracted with ethylenediaminetetraacetic acid (LP-EDTA), and LP extracted with sodium carbonate and sodium borohydride (LP-SS). Comprehensive analysis revealed low methyl-esterification in all fractions. LP-SA and LP-SS displayed characteristics of rhamnogalacturonan-I type pectin, while LP-EDTA mainly consisted of homogalacturonan pectin. Notably, LP-SA formed self-aggregated particles with rough surfaces, LP-EDTA showed interlocking linear structures with smooth planes, and LP-SS exhibited branch chain structures with smooth surfaces. Bioactivity analysis indicated that LP-SA had significant apparent viscosity and ABTS radical scavenging activity, while both LP-EDTA and LP-SS showed excellent thermal stability according to thermogravimetric analysis (TGA). Furthermore, LP-SS exhibited remarkable gel-forming ability and significant hydroxyl free radicals scavenging activity. In conclusion, this study presents a novel method for extracting various lemon pectin fractions with unique structural and bioactive properties, contributing insights for advanced applications in the food and pharmaceutical sectors.

Fermentation-inspired macroporous and tough gelatin/sodium alginate hydrogel for accelerated infected wound healing

Gelatin and sodium alginate (SA) are two important biological macromolecules, exhibiting excellent biocompatibility and gel-forming ability. However, traditional SA and gelatin hydrogel displays limited mass transport, low porosity, instability, and poor mechanical properties extremely restricted their therapeutic effect and application scenarios. Herein, microbial fermentation and synergistic toughening strategies were used for preparing macroporous and tough hydrogel. The study investigated the fermentation and toughening conditions of hydrogel. The hydrogel composed of CaCl2 cross-linked physically network and EDC/NHS cross-linked covalently network, exhibiting significantly improved mechanical properties, and excellent recovery efficiency. In addition, the hydrogel has a hierarchical macroporous structure of 100–500 μm, demonstrating high porosity of 10 times, swelling rate of 1541.0 %, and high mass infiltration capability. Further, after Ag+ treatment, the macroporous hydrogel dressing showed outstanding biocompatibility. Compared with non-porous hydrogel, the resulting macroporous hydrogel dressing displayed high antibacterial and antioxidant properties. It could effectively alleviate intracellular ROS formation induced by H2O2.In vivo experiments indicated that it has significantly better effect than non-porous hydrogel in accelerating wound healing. The overall results suggest that the gelatin/SA-based macroporous and tough hydrogel proposed in this study holds excellent prospects for application in wound dressings.

Inhibitive effect of trehalose and sodium pyrophosphate on oxidation and structural changes of myofibrillar proteins in silver carp surimi during frozen storage

This work investigated the cryoprotective effect of trehalose (TH) and sodium pyrophosphate (SPP) alone and in combination on myofibrillar protein (MP) oxidation and structural changes in silver carp surimi during 90 days of frozen storage (-20 °C). TH combined with SPP was significantly more effective than single TH or SPP in preventing MP oxidation (P < 0.05), showing a higher SH content (6.05 nmol/mg protein), and a lower carbonyl (4.24 nmol/mg protein) and dityrosine content (1280 A.U.). SDS-PAGE results indicated that TH combined with SPP did not differ significantly from TH and SPP in inhibiting protein degradation but was more effective in inhibiting protein crosslinking. Moreover, all cryoprotectants could stabilise the secondary and tertiary structures and inhibit unfolded and aggregation of MP, with the combination of TH and SPP being the best. It's worth noting that TH combined with SPP had a synergistic effect on inhibiting the decrease in α-helix content and gel-forming ability, and the increase in surface hydrophobicity. Overall, TH combined with SPP could significantly inhibited MP oxidation and structural changes in surimi during frozen storage and improve the gel-forming ability, which was significantly better than single TH or SPP.

The crosslinking sites and molecular conformation of gelatin hydrogel modified by transglutaminase

This work aimed to investigate the covalent crosslinking sites induced by transglutaminase (TGase, EC 2.3.2.13) in gelatin hydrogel and their impact on the gelatin molecular conformation. LC-MS/MS results demonstrated that Lys644 and Gln1351 of α1 chain and Gln19 of α2 chain were the main sites. The results of molecular dynamic (MD) simulation indicated that at the moderate degree of covalent crosslinking (13.55%), Radius of gyration (Rg) values decreased from 11.5 to 10.0 nm at 4 °C and led to a more compact structure, therefore enhancing structural tightness and gel strength. As the degree of crosslinking rose, the number of crosslinking sites gradually increased, with a predominant distribution in the C-terminal pro-peptide of gelatin chain. At the high crosslinking degree (37.48%), Rg value decreased at 100 °C and gelatin chains were connected through a “head to tail” linkage configuration, resulting in a significant reduction in the triple helix-like structure. The structure maintained the gel-forming ability at high temperature while lowering the aggregation energy of water molecules from −2.359 × 105 to −2.455 × 105 kJ/mol, leading to thermal irreversibility of gelatin hydrogel.

Utilization of Chia Seeds Powder in Wet Noodle Substituted with Modified Cassava Flour

The Indonesian food industry needs to utilize local food commodities as an alternative to wheat, supporting local farmers as part of sustainable agriculture. Modified cassava flour (MOCAF) has similar characteristics to wheat flour yet it lacks gluten and has low protein content. Chia seeds have the potential to improve the textural characteristics of gluten-free products due to their gel-forming ability and are a good source of plant-based protein. This study aims to utilize chia seed powder in the formulation of wet noodles substituted with MOCAF to possibly obtain wet noodles with equal textural characteristics and protein content to 100% wheat flour noodles. In this study, different ratios of wheat flour to MOCAF (100:0, 90:10, 80:20, 70:30, 60:40) and different amounts of chia seed powder (0%, 5%, 10%, 15%) are studied in terms of cooking quality (cooking loss and water absorption), textural properties (hardness, cohesiveness, and chewiness), color (brightness and hue angle). Higher MOCAF substitution resulted in higher water absorption and cooking loss, as well as undesirable (harder) textural properties. Incorporation of chia seeds powder successfully lowers the cooking loss and higher water absorption of the MOCAF-substituted noodles and noodles with 100% wheat flour without chia seeds powder. Chia seed powder can reduce the hardness while maintaining and increasing the chewiness of the MOCAF-substituted noodles. In the MOCAF-substituted noodles, comparable protein content to that of 100% wheat flour noodles can be achieved with the use of 10 to 15% chia seeds powder at a maximum 80:20 substitution ratio.

Based on hydrogen and disulfide-mediated bonds, l-lysine and l-arginine enhanced the gel properties of low-salt mixed shrimp surimi (Antarctic krill and Pacific white shrimp)

This study delved into the effects of l-lysine (Lys) and l-arginine (Arg) on the gel properties and intermolecular interactions of low-salt (NaCl, 1 g/100 g) mixed shrimp surimi (Antarctic krill and Pacific white shrimp). The addition of Lys and Arg improved the gel strength and water holding capacity of low-salt gels, which were superior to the properties of STPP and high-salt (NaCl, 2.25 g/100 g) gels. These results can be attributed to the role of Lys and Arg in enhancing hydrogen and disulfide bonds within the low-salt gel system, promoting the solubilization of myofibrillar proteins (MP) and consequently increasing the number of MP molecules participating in gel formation. Antarctic krill MP did not show gel-forming ability and exerted a diluting effect on low-salt mixed shrimp surimi gels. Molecular docking analysis indicated the stable binding of Lys and Arg to myosin.

Relatively Low Lecithin Inclusion Improved Gelling Characteristics and Oxidative Stability of Single-Washed Mackerel (Auxis thazard) Surimi.

The effect of lecithin addition on the gelling characteristics and oxidative stability of single-washed mackerel (Auxis thazard) surimi was investigated in this study. Surimi was chopped in the presence of 2.5% (w/w) NaCl with different concentrations of lecithin (0, 0.1, 0.5, 1, and 1.5 g/100 g surimi). The rheological behavior, gel-forming ability, microstructure, and lipid oxidation of lecithin-added surimi varied significantly depending on lecithin content. When compared to the control, lecithin at 0.1, 0.5, and 1 g/100 g improved the breaking force of the gel (p < 0.05). The breaking force of the gel decreased significantly as lecithin concentration increased (up to 1.5 g/100 g) (p < 0.05). Deformation, on the other hand, reacted differently to the lecithin than it did to the breaking force. At a lecithin level of 0.1 g/100 g, the surimi gel displayed improved deformation (p < 0.05). Nonetheless, at higher doses (0.5-1.5 g/100 g), lecithin considerably reduced surimi gel deformation (p < 0.05), and the gel containing lecithin at 1.5 g/100 g showed significantly decreased deformation. Surimi with 0.1 g/100 g lecithin had the lowest expressible drip (p < 0.05). In general, lecithin at concentrations ranging from 0.1 to 1 g/100 g reduced expressible drip (p < 0.05), but not at 1.5 g/100 g, which was equivalent to the control (p > 0.05). Adding lecithin to mackerel surimi improved its whiteness slightly, regardless of concentration. Lecithin impacted the microstructures of surimi gel in a concentration-dependent manner. Lecithin at a concentration of 0.1 g/100 g produced a densely packed network with small, jointed clusters and minimal holes within the gel. Joined clusters in the gel were reduced by 0.5-1.5 g/100 g lecithin, and continuous aggregates predominated. Surprisingly, at higher doses of lecithin, notably 1.5 g/100 g, porous structures with continuous voids were perceived. Surimi gels treated with various lecithin doses had lower thiobarbituric acid reactive substances (TBARS) levels than the control (p < 0.05). Overall, lecithin at a low concentration of 0.1 g/100 g was most effective at improving the texture, increasing water-holding capacity, lightening the color, and delaying lipid oxidation of single-washed mackerel surimi.

Development of an integrated device utilizing exosome-hyaluronic acid-based hydrogel and investigation of its osteogenic and angiogenic characteristics

Tissue engineering (TE) has been widely proposed as a potential solution to the global shortage of donor organs for transplantation. Organic and biocompatible materials have been explored as potential candidates to mimic natural extracellular matrices for regenerative applications. Biomimetic environments have been created using these materials, and hydrogels have shown promise in tissue regeneration due to their rapid gel-forming ability and excellent biocompatibility. Therefore, achieving comparisons between studies utilizing identical materials can prove arduous, as variations in material concentrations, sample preparation techniques, and laboratory conditions significantly influence the physicochemical characteristics of hydrogel systems. To ensure their promotion for clinical purposes, stable variables are crucial. In this regard, we have created an amalgamated and simplified device to assist in hydrogel-based systems using hyaluronic acid and alginate-loaded exosomes for regenerative medicine. The objective of this study is to examine the porosity, injectability, release of loaded exosomes, mechanical properties, and the rate of dissolution and degradation of well-known biomaterials, including alginate and hyaluronic acid, at different concentrations in a stable and controlled setting provided by a simplified integrated device. Furthermore, it aims to comprehensively assess their ex vivo and in vivo osteogenesis and vascularity-related metrics.

Gelling characteristics of fish surimi gel added with calcium hydroxyapatite (HAp)

Surimi is widely used as the main ingredient for various innovative seafood products (ISP), e.g., imitation crab meat, fish balls, fish sausage, kamaboko, fish sticks, and paupiette. Sodium chloride (NaCl), a primary ingredient of surimi, plays an important role in gelling and flavor. A reduced-NaCl product is preferred by consumers due to health-related reasons. This study focuses on evaluating the gelling characteristics of fish surimi gel formulated with different levels (0.5, 1, and 1.5%) of calcium hydroxyapatite (HAp). Surimi gel added with HAp showed a good gel-forming ability (p<0.05). The texture profile analysis indicated an acceptable value. As for the water-holding capacity (76.88%), the highest value (p<0.05) was recorded for 1% of HAp addition. On the contrary, the cooking loss (21.09%), expressible moisture content (23.48%), and whiteness index (70.20) for samples with 1% HAp were the lowest compared to other samples. This preliminary finding suggests that the addition of calcium HAp at 0.5 to 1% could be an alternative ingredient to NaCl for maintaining gelling characteristics of surimi. It also adds nutritional value to the product. This finding could be a reference to the industry in improving the processing of surimi-based products.

Sludge-derived hierarchically porous carbon electrode prepared via CaCO3-assisted dual crosslinking for enhanced phosphate electrosorption

Electrosorption is considered a promising technology to remove charged pollutants in an efficient and green way, wherein the electrode materials are crucial for achieving its high performance. In this study, a Zr-containing hierarchically porous carbon electrode (ZHPC-1-Ca) tailored for phosphate removal was synthesized based on alginate-like exopolysaccharides (ALE), a biomass extract of excess sludge. The gel-forming ability of ALE provided a basis for obtaining a conductive carbon matrix with well-dispersed metal active sites, and the pore structure of ALE-derived electrodes was simply regulated via a dual-crosslinking strategy. In the synthesis, CaCO3 acted as both the hard template and the crosslinker, while Zr facilitated pore formation during the secondary crosslinking process. ZHPC-1-Ca exhibited a maximum electrosorption capacity of 12.40 mg g−1 at 1.2 V, with a low energy consumption of 3.166 kWh kg−1-P. The electrosorption behavior was well fitted with the pseudo-first-order kinetics and the Langmuir isotherm model. Moreover, ZHPC-1-Ca maintained stable electrosorption performance under pH 4–10 and during twenty capture-release cycles (85.2%). The electrosorption mechanisms were primarily elucidated as electrostatic attraction, ligand exchange, and Lewis acid-base interaction, contributing to the enhanced and selective phosphate removal. This study achieves a simple and controllable synthesis of hierarchically porous carbon electrodes using sludge biopolymers, which extends the application of sludge-derived carbon in phosphate electrosorption.

The Effect of Multistage Refinement on the Bio-Physico-Chemical Properties and Gel-Forming Ability of Fish Protein Isolates from Mackerel (Rastrelliger kanagurta).

The objective of this research was to improve the protein extraction processes of Rastrelliger kanagurta (Indian mackerel) to generate protein isolate with enhanced bio-physico-chemical properties and gel-forming ability. To achieve this, two novel approaches were designed that utilized an additional alkaline separation step and were compared to a conventional process: acid solubilization → alkaline solubilization → pI and acid solubilization → pI → alkaline solubilization. The novel extraction designs resulted in a lower lipid content, lipid oxidation, and TCA-soluble peptides, as well as improving the color and sensory features of the refined proteins, which corresponded to the lowest total heme pigments (p < 0.05). Furthermore, the protein isolate recovered with the modified processes showed significant changes in biochemical properties (decreases in Ca2+-ATPase activity/reactive sulfhydryl content and an increase in surface hydrophobicity) and dynamic rheological behavior. As a result, by altering the extraction procedure it was possible to obtain improved gel characteristics such as gel strength, color, expelled moisture, and improved gel microstructure. Moreover, this study demonstrated that the gel network was partly stabilized by disulfide bonds, according to SDS-PAGE. Overall, this study demonstrates that by optimizing protein extraction procedures a considerable improvement in quality can be achieved and that an additional alkaline extraction after isoelectric point precipitation results in the optimized gel-forming ability of mackerel proteins.

Creation of Molecular Gel Materials Using Polyrotaxane-Derived Polymeric Organogelator.

Molecular gels, which are soft and flexible materials, are candidates for healthcare, cosmetic base, and electronic applications as new materials. In this study, a new polymeric organogelator bearing a polyrotaxane (PR) structure was developed and could induce the gelation of N',N″-dimethylformamide (DMF), a known solvent for dissolving polymeric materials and salts. Furthermore, the resulting DMF molecular gels exhibited thixotropic properties, observed by the inversion method using vials, which are essential for gel spreading. The scanning electron microscopy of the xerogels suggested that the gel-forming ability and thixotropic property of gels were imparted by the network of the laminated aggregates of thin layer material similar to those of other gels made of clay materials. This thin layer material would be formed by the aggregation of polymeric organogelators. The dynamic viscoelasticity measurements of the obtained gels revealed the stability and pseudo-thixotropic behaviors of the obtained gels, as well as a specific concentration effect on the mechanical behavior of the gels attributed to the introduction of the PR structure. Additionally, the preparation of the polymer organogelator/polymer composites was investigated to improve the mechanical properties via the filler effect induced by the agglomerates of organogelator. Moreover, the tensile tests confirmed that the introduction of the gelator enhanced the mechanical properties of the composites.