Search Results (348)

Polysaccharide-based hydrogels represent promising platforms for the development of bioactive wound dressings due to their biocompatibility, bioadhesive properties, and ability to maintain a moist environment at the wound interface. In this study, polymeric films were developed from natural polysaccharides incorporating olive mill wastewater (OMW) as a natural antibacterial agent. Chitosan (medium molecular weight), sodium alginate, sodium hyaluronate, and xanthan gum were selected to prepare hydrogel formulations either as single polymers or binary mixtures. Hydrogels were prepared by aqueous dispersion under magnetic stirring and subsequently converted into films using a solvent casting method. The resulting films were characterized in terms of rheological behavior, pH, morphology, thickness and water content. The obtained hydrogel films showed good casting ability, producing smooth and homogeneous matrices with adequate deformability and skin adhesion. Furthermore, they demonstrated a suitable capacity to absorb and retain water, mimicking the management of wound exudate. OMW was incorporated into the hydrogel formulations as a source of phenolic compounds with well-known antioxidant and antimicrobial properties. The presence of these bioactive compounds provides the films with potential antibacterial and antibiofilm activity against clinically relevant multidrug-resistant staphylococcal strains. These findings suggest that OMW-loaded polysaccharide hydrogels represent a promising and sustainable strategy for the development of antibacterial films for wound healing applications. Full article

Calcium-induced polysaccharide hydrogels have attracted growing interest in food science because of their mild gelation conditions, tunable structures, and compatibility with food-grade formulation. This review focuses on edible Ca²⁺-mediated polysaccharide hydrogels and related composite networks, focusing on alginate, low-methoxyl pectin, gellan gum, and carrageenan. Rather than treating all calcium-containing polysaccharide materials as well-defined complexes, we distinguish direct coordination, ionic bridging, charge screening, helix stabilization, and composite-assisted network regulation. Current evidence indicates that Ca²⁺-mediated assembly is governed by polysaccharide fine structure, calcium-release behavior, pH, ionic strength, and processing conditions, thereby determining crosslinking density, digestibility gel strength, water distribution, rheological properties, release behavior, and texture-related functionality. For texture-modified foods for older adults, these hydrogels may provide a useful material basis for designing swallowing-friendly matrices, sustained nutrient-delivery systems, and soft composite foods. However, available evidence is still largely derived from model gels, in vitro characterization, and static digestion models, while validation in real food matrices, dynamic gastrointestinal conditions, oral processing, sensory acceptance, and older-adult populations remains limited. Future studies should establish structure–function–population evidence chains linking molecular assembly to reliable geriatric food performance. Full article

Visual freshness monitoring is challenging in intelligent seafood packaging. This study developed low-acyl gellan gum (LGG)-based intelligent films incorporating anthocyanin (BRE), carboxymethyl chitosan (CMCh), and black rice starch (BRS) and evaluated their effects on film structure, physical–mechanical properties, and shrimp freshness-monitoring performance. Films prepared via solution casting were evaluated using structural, mechanical, and barrier analyses, alongside shrimp spoilage trials at 25 °C. Structural analyses revealed an integrated polysaccharide network. CMCh reinforced the matrix and increased tensile strength, whereas partially retained BRS granules introduced microstructural heterogeneity, reducing strength and increasing water vapor permeability, highlighting a trade-off between mechanical performance and moisture transport. Consequently, BRS-containing films reduced BRE release, improved pigment retention, and resulted in less intense color changes associated with total volatile basic nitrogen (TVB-N) accumulation during shrimp spoilage. Overall, these results suggest that CMCh and BRS composition-dependently modulate the structure, water vapor transport, pigment retention, and colorimetric response of LGG-based films for visual monitoring of shrimp freshness under accelerated spoilage conditions. Full article

Extensive efforts have been undertaken by numerous researchers to control respiratory viruses across the domains of diagnosis, prevention, and treatment. In this study, we developed a niclosamide–polysaccharide nasal spray (NPNS) formulation based on xanthan gum (XG), a naturally derived polysaccharide, and niclosamide, a conventional anthelmintic agent. We then evaluated its therapeutic efficacy following intranasal administration under influenza virus-infected conditions. NPNS was assessed for cytotoxicity under Good Laboratory Practice (GLP) conditions in accordance with ISO 10993-5, and no cytotoxic effects were observed. In influenza virus-infected human nasal epithelial cells (HNEc), NPNS treatment resulted in at least 92.5% suppression of viral gene expression. Furthermore, NPNS demonstrated significantly greater antiviral activity compared to Placebo 1 and Placebo 2, which were formulated by excluding niclosamide and XG, respectively. Owing to the physicochemical properties conferred by XG, NPNS exhibited prolonged retention on the nasal mucosa in a mouse model. Consistently, NPNS showed potent antiviral efficacy in influenza-infected mice. In addition, NPNS treatment was associated with the downregulation of S-phase kinase-associated protein 2 (SKP2), a host factor known to facilitate intracellular viral replication. Collectively, these findings suggest that NPNS may serve as a first-line protective barrier during the early stage of influenza infection by simultaneously blocking viral entry and suppressing viral replication through its dual physicochemical and molecular mechanisms. Full article

This study examined Kefiran, an exopolysaccharide derived from milk kefir grains, as a novel biopolymer for encapsulating phenolic extracts from sunflower cake and its antimicrobial properties in the development of natural and functional food ingredients. Kefiran was obtained from kefir grains using three extraction protocols: hot water (M1), hot water with 30% trichloroacetic acid (M2), and mild heat combined with ultrasound at 60 °C (M3). The ultrasound-assisted method produced the highest carbohydrate concentration. Spectrophotometric assays (phenol–sulfuric and Bradford), Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and water-holding capacity were employed to characterize the composition, structure, and morphology of the extracts, revealing well-preserved polysaccharide fingerprints and a highly porous microstructure, consistent with their potential application in food systems. Kefiran was then evaluated as an encapsulating agent in complex coacervation at pH 3.75, using three Kefiran-based wall formulations (M1, M2, and M3) with gum arabic and whey protein isolate (WPI) as co-wall materials, and their performance was compared with gum arabic and WPI controls. Across formulations, coacervate microcapsules achieved high encapsulation efficiencies (83–93%), tunable particle sizes, and predominantly negative zeta potentials, indicative of good colloidal stability. The Kefiran extract and coacervate microcapsules demonstrated significant antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, with minimum inhibitory concentrations ranging from 250 to 1000 µg/mL. The findings support ultrasound-extracted Kefiran as a multifunctional biopolymer suitable for bioactive delivery and as a natural antimicrobial component in advanced functional food formulations. Full article

Sodium caseinate (SC)-stabilized emulsions are highly susceptible to flocculation and phase separation near the protein isoelectric point (pI), limiting their application in acidified food systems. In this study, high acyl gellan gum (HA) was introduced to construct pH-responsive protein–polysaccharide complexes to modulate the interfacial assembly and stability of SC emulsions. Results demonstrated that HA interacts with SC primarily through electrostatic attraction and multi-site hydrogen bonding. This interaction induces protein conformational rearrangement and, as evidenced by combined structural and computational analyses, facilitates the assembly of a denser, interconnected composite network. The formation of HA–SC complexes significantly enhanced interfacial adsorption, reduced oil–water interfacial tension. Rheological and microrheological analyses revealed the composite system formed an elasticity-dominated weak gel network, restricting droplet mobility and suppressing aggregation. Consequently, HA–SC emulsions exhibited markedly improved pH tolerance and physical stability compared to SC-only emulsions, particularly near the pI, evidenced by reduced droplet size, lower Turbiscan stability indices, and more homogeneous microstructures. Crucially, utilizing a well-defined mechanistic model of fixed HA and SC concentrations, this study quantitatively links molecular interactions, interfacial network reconstruction, and macroscopic emulsion stability across a broad pH continuum. Rank-correlation analysis of pH-resolved descriptors shows the molecular charge state co-varies monotonically with the interfacial network and macroscopic stability, and is inversely coupled to droplet mobility. These findings provide new insights into protein–polysaccharide interfacial engineering, establishing the essential physical-stability foundation for the future rational design of acid-tolerant food emulsions and functional delivery systems. Full article

The Senegal tree (Sengalia senegal) is the primary plant source of Gum Arabic (GA), a natural secretion rich in soluble fiber and bioactive polysaccharides. It has longstanding uses in traditional medicine, nutrition, and pharmaceuticals. The present study aimed to evaluate the phytochemical profile, antimicrobial, anti-inflammatory, and anticancer activities of GA methanolic extract (GAME), supported by molecular docking analysis of its key compounds. The gas chromatography–mass spectrometry (GCMS) analysis of the GAME identified many compounds, such as 9-octadecenoic acid (38.29%), methyl ester (15.52), 1,2-benzenedicarboxylic acid, 3-nitro (9.8%), hexadecadienoic acid, methyl ester (8.5), and á-d-mannofuranoside, methyl (7.38). The molecular docking analysis showed that 9-octadecenoic acid had strong binding affinity with target proteins, which included xanthine oxidase (XO), lipoxygenase (LOX), and cyclooxygenase-2 (COX-2), with the highest affinity to XO (−137.03 kcal/mol) and lipoxygenase (−135.09 kcal/mol). GAME possessed broad-spectrum antibacterial activity against Salmonella typhimurium (S. typhimurium), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus), with a zone of inhibition from 16.28 to 16.93 mm. B. subtilis was resistant to the tested extract. The extract also showed good membrane stability and potent inhibition of albumin, XO, LOX, and COX-2, with IC₅₀ values of 31.62, 13.02, 27.6, and 28.99 μg/mL, respectively. The cytotoxic assessment demonstrated moderate, dose-dependent effects on the Caco-2 (colorectal adenocarcinoma) and HeLa (cervical carcinoma) cell lines. These findings highlight the therapeutic potential of GA as a natural plant source of antibacterial, anti-inflammatory and anticancer agents. The combination of molecular docking with in vitro assays provides strong evidence supporting its application in the development of plant-based pharmaceuticals. This research suggests that GA could be a useful ingredient in the creation of anti-inflammatory and antibacterial drugs derived from plants. Full article

Myocardial infarction (MI) triggers excessive oxidative stress, a detrimental immune response, and insufficient angiogenesis, which collectively impede effective cardiac repair. This study developed a multifunctional composite polysaccharide hydrogel, termed KgXd^gel, based on konjac glucomannan (KGM) and xanthan gum (XG) functionalized with gallic acid (GA) and dopamine (DA), respectively, to integrate reactive oxygen species (ROS) scavenging, macrophage polarization, and pro-angiogenic activities. In vitro assays demonstrated that the KgXd^gel hydrogel exhibited excellent cytocompatibility, effectively scavenged ROS, promoted the polarization of macrophages towards the reparative M2 phenotype, and enhanced the migration and tube formation of human umbilical vein endothelial cells. In a rat MI model, treatment with KgXd^gel significantly improved cardiac function (e.g., left ventricular ejection fraction, LVEF; left ventricular fractional shortening, LVFS), attenuated left ventricular dilation (LVIDs), and favorably modulated the post-infarction microenvironment. This was evidenced by the upregulation of the M2 marker CD163 and the angiogenic factor VEGF, alongside the downregulation of pro-inflammatory cytokines (e.g., IL-1β, TNF-α) and the M1 marker iNOS. These findings conclusively demonstrate that the KgXd^gel hydrogel synergistically promotes cardiac repair post-MI through its integrated antioxidant, immunomodulatory, and pro-angiogenic functions, presenting a promising multi-targeted therapeutic strategy. Full article

Background/Objectives: Tuberculosis treatment remains challenging due to the limited stability and side effects of conventional rifampicin formulations. This study aimed to synthesize and optimize mucoadhesive chitosan–gellan gum nanoparticles for improved rifampicin delivery. The novelty of this work was the introduction of ethanol into the synthesis process, which improved the solubility of rifampicin and contributed to the formation of nanoparticles with the desired physicochemical characteristics. Methods: Rifampicin-loaded chitosan–gellan gum nanoparticles were produced using the polyelectrolyte complex coacervation method. The polymer ratios, drug-to-polymer ratio, temperature and ethanol volume were the main factors that were optimized using the Taguchi method. The physicochemical properties, such as TGA, DSC and FTIR spectroscopy, were investigated. In addition, drug release, mucoadhesive properties and mycobacterial activity against the H37Rv strain of Mycobacterium tuberculosis were examined. Results: Optimization using the Taguchi method produced nanoparticles with a narrow particle distribution (PDI: 0.212 ± 0.021), a satisfactory average size (153 ± 3 nm) and stability against aggregation (zeta potential: 22.94 ± 1.30 mV). A study of the degree of rifampicin release from nanoparticles showed that the drug release is influenced by pH and has a prolonged effect. Drug-loaded nanoparticles exhibited increased mucoadhesion compared with the pure drug. The minimum inhibitory concentration of rifampicin in chitosan–gellan gum nanoparticles for the suppression of the H37RV strain of Mycobacterium tuberculosis was determined. Spectroscopic and thermal analyses confirmed the incorporation of rifampicin in the polymer matrix. Conclusions: The developed chitosan–gellan gum nanoparticles represent a promising mucoadhesive delivery system for rifampicin. The incorporation of ethanol and the use of Taguchi optimization provide an effective strategy for controlling nanoparticle properties and improving drug delivery performance. Full article

Proton exchange membrane fuel cells (PEMFCs) are among the most promising clean energy conversion technologies, offering high efficiency and zero emissions. However, their large-scale commercialisation is limited by the high cost and environmental impact of conventional perfluorosulfonic acid membranes such as Nafion. In recent years, increasing attention has been directed toward biopolymer-based membranes as sustainable, low-cost, and biodegradable alternatives. This review provides a comprehensive overview of recent advances in the development and modification of biopolymer membranes, including polysaccharide-based materials such as chitosan, cellulose, gellan gum, sodium alginate, and starch, as well as protein-based materials such as keratin and collagen. Various modification strategies, including sulfonation, phosphorylation, cross-linking, and incorporation of inorganic or hybrid fillers, are analysed for their impact on key parameters, including proton conductivity, methanol permeability, and power density. Comparative data indicate that several modified biopolymer membranes achieve proton conductivities of 50 mS/cm or higher. However, higher conductivity values are generally reported for membranes primarily composed of synthetic polymers, where the biopolymer is incorporated only as an additive. In addition, some biopolymer-based membranes exhibit significantly lower methanol permeability than Nafion. The lowest reported value among the membranes discussed in this article is 0.98 × 10⁻¹⁶, representing the best-performing biopolymer membrane in terms of methanol permeability alone. Although many biopolymer membranes demonstrate relatively poor performance in single PEMFC tests, several have achieved power densities comparable to Nafion, while simultaneously offering improved environmental compatibility and sustainability. Finally, current challenges and future directions are discussed, emphasising the potential of these renewable materials to advance PEMFC technology toward more sustainable and economically viable energy systems. Full article

Starch (native and modified) is a major polymer in baked goods, affecting dough rheology, crumb structure, and shelf life. This review covers recent advances in starch functionalization for baking, including chemical, physical, and enzymatic modifications. It further examines how other polysaccharides (e.g., gums and fibres) modulate starch-based systems, and finally addresses strategies to reduce fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) in bakery products. Emphasis is placed on novel technologies, trade-offs (prebiotic fiber vs. FODMAPs), and gaps needing future research. Full article

This study comparatively investigates the efficacy of two natural, plant- and microbe-derived polysaccharides—xanthan gum (XG) and guar gum (GG)—in enhancing the water stability and shear strength of granite residual soil (GRS). GRS specimens treated with varying dosages of XG and GG were cured for 14 days and subsequently evaluated through direct shear and static-water disintegration tests. Concurrently, scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR) were employed to elucidate the underlying microstructural and pore-scale mechanisms. Direct shear test results indicate that the peak shear strength reached 295.9 kPa (2.0% GG) and 221.0 kPa (1.5% XG), representing increases of 58.2% and 35.7%, respectively. Quantitatively, GG and XG treatments yielded maximum internal friction angle improvements of 52.96% and 39.37%, with peak cohesion increases of 55.27% and 35.7%, respectively. During static-water immersion, the untreated GRS suffered complete disintegration within 200 s. In contrast, the 2.0% GG- and XG-treated specimens preserved overall structural integrity for 24 h. SEM observations revealed that XG and GG reconstruct the soil fabric by forming encapsulating films and interparticle bridging structures. Finally, LF-NMR analysis provided definitive quantitative proof of a “pore refinement” effect, where biopolymer treatment shifted the primary $T_2$ peaks from 4.64 ms to 3.51 ms. Notably, at a 2.0% dosage, dramatic NMR signal surges (up to 747.5 a.u. for XG and 704.3 a.u. for GG) revealed that excessive biopolymers tend to form localized ‘gel lumps’ rather than uniform films. These blobs weaken the biting force between soil particles, thereby accounting for the observed degradation in shear strength. Full article

Blueberry anthocyanins (BAs) exhibit strong antioxidant and lipid-regulating activities; however, their chemical instability and low oral bioavailability limit their practical application. In this study, two plant-based bilayer nanocarriers were developed using soybean lecithin as the lipid core and gum arabic (GA) or carrageenan (CGN) as the shell polysaccharide. The optimized systems achieved encapsulation efficiencies of 79.7% and 81.9%, respectively. Structural analyses showed that anthocyanins were stably incorporated into the carriers through multiple non-covalent interactions and transformed from a crystalline to an amorphous state. The two shell polysaccharides exhibited distinct conformation-dependent protective behaviors: GA provided better thermal protection, whereas CGN showed superior resistance to light, metal ions, ascorbic acid, and simulated intestinal digestion. After INFOGEST digestion, anthocyanin retention in the intestinal phase was 47% and 51% for the GA- and CGN-coated systems, respectively, and antioxidant activity was better preserved than in the free anthocyanin group. In an oleic-acid-induced HepG2 lipid accumulation model, the CGN carrier showed good biocompatibility and significantly enhanced the lipid-lowering effect of anthocyanins, with the most pronounced reduction in intracellular triglycerides. These results indicate that the CGN carrier has considerable potential for maintaining anthocyanin stability, modulating digestive behavior, and enhancing biological efficacy, and provide a reference for the design of plant-based delivery systems for bioactive ingredients. Full article

The synergistic gelation between xanthan gum (XG) and locust bean gum (LBG) is a classic phenomenon widely adopted for quality control of XG functionality; yet the regulatory roles of XG’s side chain groups—particularly glucuronic acid, whose function remains unexplored—have not been systematically elucidated. In this study, three complementary modification strategies including enzymatic hydrolysis, oxalic acid treatment, and dilute alkali treatment were for the first time combined to precisely modulate the contents of pyruvate, acetyl, and glucuronic acid in XG side chains, constructing a series of XG samples with well-defined gradient structures. Enzymatic hydrolysis and oxalic acid treatment reduced the pyruvate content from 5.80% to 1.05% and 1.42%, respectively, while dilute alkali treatment selectively decreased the acetyl content from 3.97% to 2.58%. The effects were systematically investigated through multi-scale characterization including rheology, texture analysis, scanning electron microscopy and thermogravimetric analysis, combined with correlation analysis. The results revealed that glucuronic acid, together with pyruvate, synergistically enhanced gel network stability through electrostatic interactions and hydrogen bonding. In contrast, acetyl groups acted as negative regulators via steric hindrance, inhibiting hydrogen-bond crosslinking. This study clarifies the distinct functional roles of key XG side chain groups, with the first systematic demonstration of glucuronic acid’s contribution, and provides a theoretical basis for the structure-oriented precise design of XG-based functional gels. Full article

Electrostatic protein–polysaccharide hydrogels are attractive materials formed without thermal denaturation or chemical crosslinkers and at low biopolymer contents. Their broader application in foods, however, has been limited by slow gelation, with network development often requiring many hours (~18 h). In this study, millimeter-scale hydrogel beads were fabricated from amaranth proteins and xanthan gum by extrusion into glucono-δ-lactone (GDL) solutions (1–5 mg/mL) using hardening times of 10 or 30 min. Beads were successfully formed under all conditions (3.07–3.95 mm diameter), and their physicochemical properties, intermolecular interactions, microstructure, and gel strength were evaluated. Electrostatic attraction remained the dominant force driving gelation. Furthermore, 10 min hardening favored interpolymeric electrostatic interactions, whereas longer exposure reduced them and promoted hydrogen bonding and hydrophobic interactions. These molecular rearrangements were accompanied by a decreased size, lower water retention capacity (WRC), and higher mechanical strength. The mildest treatment (1 mg/mL GDL, 10 min) was post-loaded with a coffee pulp phenolic extract and showed reduced gel strength and electrostatic interactions, suggesting competition for binding sites within the macromolecular network. The extrusion of amaranth protein–xanthan gum mixtures into a GDL bath markedly shortens electrostatic gelation time, supporting this approach as a potential alternative to ionic gelation for the production of millimeter-scale hydrogel beads for food applications. Full article