Search Results (251)

Oral administration of narrow therapeutic index anticoagulants like phenprocoumon (PHP) necessitates careful control of the kinetic release of the drug to avoid dose dumping and severe haemorrhagic effects. This study was carried out to prepare and characterize novel PHP delivery systems based on κ-carrageenan hydrogels, exploring the importance of potassium ion (K⁺) stabilization in controlling the release process. FT-IR, TG/DTG, and in vitro release studies were employed in combination with a new validated RP-HPLC assay. FT-IR and thermal analysis results showed that PHP is physically encapsulated into the polysaccharide matrix, where there are no chemical incompatibilities between them. Furthermore, potassium ions increase the stability and heat resistance of the polymer network. However, when K⁺ was considered for modelling the kinetic release using the Korsmeyer–Peppas equation, it was observed that PHP is released from the K⁺ stabilized matrix in a relaxation dominated diffusion-controlled transport. Ionic cross-linking effectively reduces the initial burst effect, demonstrating that these matrices are promising vehicles for the sustained delivery of phenprocoumon. Full article

Three-dimensional (3D) food printing enables personalized fabrication but requires materials with suitable printing properties. This study developed high internal phase Pickering emulsions (HIPPEs) stabilized by co-assembled whey protein isolate (WPI) with κ-carrageenan (κ-CA) in a binary system and with both κ-CA and curdlan gum (CG) in a ternary system. The aim was to clarify the distinct roles of anionic and neutral polysaccharides in regulating emulsion printability. Incorporation of 1.2% κ-CA and 1.6% CG optimized the three-phase contact angles of the binary and ternary particles to 78.84 ± 0.87° and 86.22 ± 0.74°, respectively. The ternary system exhibited significantly greater oil-phase wettability (p < 0.05). Rheological and textural analyses showed that κ-CA concentration primarily governed yield stress and self-supporting capacity in the ternary system, with an optimum at 1.2%. In contrast, CG incorporation was essential for improving thixotropic recovery and printing accuracy, with an optimum at 1.6%. The optimized ternary HIPPEs exhibited excellent 3D printing accuracy with a food-grade oil phase and surpassed the binary system in structural integrity and shape fidelity. These findings clarify the distinct yet complementary roles of anionic and neutral polysaccharides in modulating HIPPEs printability and provide a rational material-design strategy for developing high-performance food 3D-printing system. Full article

Rice (Oryza sativa L.) is one of the world’s major staple foods. However, its production is severely constrained by rice blast disease, caused by Magnaporthe oryzae, which leads to substantial yield losses. Conventional management relies on fungicides and chemical treatments; however, these methods raise concerns regarding the development of pathogen resistance and potential environmental impacts. This study evaluated carrageenan from Hypnea musciformis, collected from the coast of Saint Martin (92°19′21.28″ E and 20°37′38.12″ N), located in the Bay of Bengal, Bangladesh, as a natural plant growth promoter as well as a biocontrol agent. Carrageenan was characterized by high sulfate (19–35%) and galactose (12–18%) contents, with FT-IR confirming characteristic κ-carrageenan functional groups. Application of 15% carrageenan significantly increased the germination of seed (27%), seedling vigor (93%), shoot and root lengths (54% and 47%), and biomass compared with untreated controls. Carrageenan markedly suppressed M. oryzae, inhibiting mycelial growth (83%), reducing conidiogenesis and conidial germination, and decreasing lesion length in detached leaves and potted plants. Treated rice seedlings exhibited improved soluble sugars, photosynthetic pigments, proline, phenolic and flavonoid contents, and enhanced antioxidant enzyme activities such as CAT (catalase) and POD (peroxidase), while lowering oxidative stress markers such as H₂O₂ and MDA (malondialdehyde). These results demonstrate that carrageenan from H. musciformis enhances rice growth and elicits defense responses against rice blast, offering a sustainable and environmentally friendly alternative to chemical-based fungicides for integrated M. oryzae management. Full article

The present study evaluated the feasibility of replacing soy protein isolate with collagen and plasma proteins, either individually or in combination with κ-carrageenan, xanthan gum, and sodium tripolyphosphate, in an emulsion-type pork sausage, based on selected physicochemical, compositional, and textural quality parameters. Six formulations were produced, including a control and five reformulated variants in which soy protein was fully replaced by a mixture of collagen (1.88%) and plasma proteins (3.4%), used alone or supplemented with κ-carrageenan (1.0%), xanthan gum (0.2%), and sodium tripolyphosphate (0.2%). Moisture, protein, fat and collagen contents, color, pH, and sensory properties were analyzed after processing, while TBARS values and textural properties were assessed initially and after 30 days of storage. As a result of the reformulation, collagen content increased by 32.35–40.33%, while the collagen-to-protein ratio remained within legal limits (<20%). Soy protein replacement increased textural parameters, including hardness, cohesiveness, gumminess, chewiness, and shear force. Carrageenan and sodium tripolyphosphate enhanced texture and oxidative stability, whereas xanthan gum negatively affected texture quality and sensory acceptance. The formulation containing collagen, plasma proteins, carrageenan (1%) and sodium tripolyphosphate (0.2%) achieved the highest sensory scores, comparable to those of the control. The results show that replacing soy protein in an emulsion-type pork sausage is feasible when using optimized combinations of collagen, plasma proteins, and κ-carrageenan systems. Full article

This work aimed to develop bioactive films based on alginate and κ-carrageenan that were incorporated with different concentrations 0, 0.2, 0.4, 0.8, 1 and 2% (w/v) of cinnamon essential oil (CEO). The films were crosslinked with a solution of calcium chloride obtained from limestone sludge through acid dissolution. The films were characterised according to their physical, mechanical, optical, antioxidant and antimicrobial properties. The best film formulation consisted of 1.5% total carbohydrate concentration, 0.45% glycerol and 0.4% (w/v) of Tween 20. The Fourier transform infrared Spectroscopy analysis confirmed the crosslinking between the polysaccharides and the incorporation of the CEO into the polymer matrix. The addition of the CEO increased the film thickness, reduced moisture content and water vapour permeability, yet it increased solubility, due to matrix disruption invoked by the oil droplets. SEM analysis showed that CEO affected film microstructure, with moderate concentrations leading to more homogeneous structures. In terms of the mechanical properties, CEO incorporation reduced stiffness and yield strength whilst increasing film flexibility, showcasing a plasticising effect. The films were colourless and transparent; moreover, none of the samples exhibited absorbance in the visible region (400–800 nm); however, all films showed absorption in the UV region. The incorporation of the CEO into the films provided antioxidant activity. Particularly, the sample containing 2% CEO had the highest activity, with values of 97.5 ± 0.77% and 75.9 ± 1.82% in the ABTS and DPPH, respectively. Overall, these results suggest that the developed films have promising potential as sustainable food packaging materials with enhanced antioxidant functionality, although further optimisation is needed to improve antimicrobial performance and validate their effectiveness in real food packaging systems. Full article

Extrusion-based three-dimensional food printing requires inks that can be smoothly extruded while maintaining sufficient structural stability after deposition. In this study, gelatin and κ-carrageenan were first mixed and then subjected to post-mixing pH regulation before spray drying, producing composite powders with different structural states. These powders were incorporated into yellow peach pulp gels to prepare fruit-based printing inks, and their printing performance, extrusion behavior, mechanical properties, particle-size distribution, and microstructure were systematically evaluated. The results showed that the structural state formed during gelatin–κ-carrageenan powder preparation was closely associated with the extrusion stability and shape retention of the final inks. Among the tested formulations, the ink prepared with gelatin–κ-carrageenan powder pre-regulated to pH 4.0 exhibited the best overall printability. Although its pore-area fidelity was slightly lower than that of the sample pre-regulated to pH 3.5, it produced more stable multilayer cylinders and better-defined lattice structures. In addition, the pH 4.0 sample showed the lowest and most stable extrusion force and the highest Young’s modulus, indicating a favorable balance between extrusion flowability and post-deposition support. Microstructural observations and particle-size analysis suggested that pH regulation altered the aggregation state and local morphology of the gelatin–κ-carrageenan system. Samples prepared at higher pH values tended to form larger and less uniform aggregates, which was unfavorable for stable extrusion and shape retention. Overall, post-mixing pH regulation of gelatin–κ-carrageenan provides a practical strategy for improving the printing-related properties of fruit-based gel inks. Full article

Colletotrichum species are among the most destructive phytopathogens worldwide, with appressorium-mediated penetration representing a critical stage in host infection. Targeting this morphogenetic transition offers a promising strategy for sustainable disease control by interfering with the infection process rather than solely inhibiting fungal growth. In this study, chitosan–κ-carrageenan nanoparticles (CS–κ-CRG) without and with lysozyme (CS–κ-CRG/Lz) were synthesized, characterized, and evaluated for their ability to inhibit appressorium formation in Colletotrichum siamense, a strain exhibiting low sensitivity to chitosan. The nanoparticles showed monodisperse size distributions, with hydrodynamic diameters of 503 and 333 nm for CS–κ-CRG and CS–κ-CRG/Lz, respectively, positive surface charges of approximately +26 mV, spherical morphology, and a lysozyme encapsulation efficiency of 63%. Both formulations significantly reduced conidial viability and delayed germination, inducing morphological alterations such as conidial swelling, hyphal deformation, and vacuolization. Fluorescence microscopy using calcofluor white and propidium iodide revealed disturbances in cell wall organization and loss of membrane integrity. Both nanomaterials markedly affected appressorium development in a concentration- and formulation-dependent manner. Notably, CS–κ-CRG/Lz showed stronger suppression of appressorium formation, whereas at 200 µg·mL⁻¹, CS–κ-CRG nanoparticles stimulated appressorium formation, suggesting that sublethal nanoparticle stress may trigger compensatory or hyper-pathogenic responses. These findings highlight the potential and complexity of utilizing chitosan-based nanomaterials for phytopathogen management and emphasize the importance of mechanistic and dose–response evaluations before field application. Full article

Antarctic krill protein (AKP) was conjugated with three reducing monosaccharides (ribose, glucose, fructose) and five polysaccharides (xanthan gum, konjac glucomannan, inulin, κ-carrageenan, and pectin) via a controlled Maillard-type glycation process (pH 7.0, 90 °C, 24 h). We comparatively evaluated glycation reactivity (color change and degree of glycation), structural responses (particle size, FTIR, intrinsic fluorescence, surface hydrophobicity, and microstructure), and key techno-functional properties (solubility, water- and oil-holding capacities, and emulsifying performance). Monosaccharide-conjugated AKP exhibited stronger browning and higher apparent glycation activity, consistent with the higher reactivity of small-molecule sugars. In contrast, polysaccharide-conjugated AKP showed more pronounced improvements in dispersion-related and interfacial functions, reflecting enhanced steric stabilization and hydration after polysaccharide grafting. Notably, κ-carrageenan conjugation delivered the strongest overall functional enhancement (water-holding capacity ≈ 22.1 g/g; oil-holding capacity ≈ 10 g/g) and the most stable emulsions. These findings clarify how glycosylating-agent size and architecture steer AKP glycation outcomes, providing a practical basis for tailoring AKP ingredients for aqueous and emulsion-based foods. Full article

To address the environmental sensitivity and low bioavailability of riboflavin, this study constructed a soybean protein isolate fibril (SPF)/κ-carrageenan (κC) composite gel delivery system. This study systematically investigated the effects of two independent variables (protein type: SPI/SPF; κC concentration: 2, 4, 6, 8 mg/mL) on the gel structural stability, riboflavin encapsulation performance, and in vitro digestive delivery characteristics of the system. Thioflavin T (ThT) fluorescence and ultraviolet (UV) absorption spectroscopy confirmed the successful preparation of SPF and verified specific intermolecular interactions between SPF and κC. Intermolecular forces, protein leaching rates, and differential scanning calorimetry (DSC) results indicated that compared with SPI-κC composite gels, κC regulates SPF molecular conformation via hydrogen bonding and hydrophobic interactions to exert a synergistic effect. This conformational regulation significantly reduced the protein leaching rates in SPF-κC composite gels, elevated the thermal denaturation temperatures (up to 79.82 °C), and enhanced the gel structural stability. As the κC concentration increased, the environmental stability of SPF-κC riboflavin-loaded composite gels were markedly enhanced, which effectively delayed the gel degradation during simulated gastrointestinal digestion. This was manifested as a reduced protein loss rate (reduced to 22.23%). At a κC concentration of 8 mg/mL, the in vitro release mechanism of riboflavin shifted from Fickian to non-Fickian diffusion. Full article

Hydrogels derived from biopolymers have attracted considerable interest in biomedical applications because of their biocompatibility and structural similarity to the extracellular matrix (ECM). Bacterial Cellulose (BC), despite being a promising biopolymer for hydrogel preparation, lacks antimicrobial properties itself. To address this drawback, we prepared Probiotic Bacterial Cellulose (PBC) in our laboratory, which has intrinsic antibacterial properties. No research was found on the preparation of a hydrogel using PBC and κ-carrageenan, which motivated us to develop a PBC/κ-carrageenan-based hydrogel. In the study, a novel biocomposite hydrogel system has been developed by integrating PBC with κ-carrageenan, yielding a multifunctional hydrogel with enhanced antibacterial properties and biocompatibility. The novel hydrogel has been evaluated for its structural, physicochemical, antibacterial, and biocompatible properties. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the formation of intermolecular interactions between PBC and κ-carrageenan. Scanning electron microscopy (SEM) images revealed a porous internal morphology and the presence of probiotic bacteria within the hydrogel networks. Porosity analysis and swelling behaviour indicated an elevated water uptake capacity and structural stability. The composite hydrogel demonstrated promising antibacterial properties against pathogenic bacteria Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) and exhibited favourable in vitro biocompatibility. The developed PBC/κ-carrageenan hydrogel exhibits a synergistic combination of porosity, swelling capacity, biocompatibility, and antibacterial activity, making it a potential candidate for healthcare applications viz. wound healing and other tissue engineering applications. Full article

Kappa-carrageenan (κ-CRG) forms thermo-reversible physical hydrogels via a coil–helix transition and helix bundling, but its sulfate-driven electrostatic repulsion limits mechanical robustness and control over aqueous disintegration. Here, we show that plant-derived polyphenols reprogram κ-CRG gel through sulfate-directed binding in a structure-dependent manner. Tannic acid (TA) selectively engages κ-CRG sulfate groups, yielding transparent gels and a >5-fold increase in storage modulus, whereas the same TA triggers turbidity and precipitation in sulfate-free agarose, supporting sulfate-mediated specificity. Using monomeric pyrogallol as a galloyl analogue, we demonstrate that monovalent interactions partially reinforce κ-CRG but lack cooperative stabilization. Intervention timing further separates mechanism. Pyrogallol produces pathway-dependent mechanics and gelation temperature, while TA is stage-insensitive, consistent with multivalent network annealing. In simulated gastric/intestinal fluids, pyrogallol/κ-CRG gels retain morphology longer, whereas TA/κ-CRG ones disintegrate rapidly yet exhibit strong adhesion to rough substrates and human skin. These findings provide a fully food-grade route to tune κ-CRG mechanics, thermal behavior, adhesion and programmed disintegration. Full article

This study examined the structural, rheological, and digestive properties of plant-based emulsion-filled gels (EFGs) formulated for dysphagia-friendly nutrition. EFGs were created using a pea protein–κ-carrageenan (PP–κ-CAR) matrix that incorporated oil droplets stabilized by pea protein (EFG-PP), soy lecithin (EFG-PP/LEC), or mono-/diglycerides (EFG-PP/MDG). All formulations met the International Dysphagia Diet Standardisation Initiative Level 6 requirements and showed improved viscoelastic properties compared to the hydrogel control. The interfacial composition determined how the oil droplets influenced the gel network, with droplets in EFG-PP and EFG-PP/MDG contributing to greater reinforcement, whereas those in EFG-PP/LEC resulted in a weaker and more deformable structure. Among the formulations, EFG-PP/LEC demonstrated the most suitable properties for dysphagia management, including the lowest yield stress, softest texture, and highest protein hydrolysis (54%) and free fatty acid release (7.35 µmol/mL). These effects were associated with weaker oil–matrix interactions and greater enzymatic accessibility. The findings highlight the importance of interfacial design in tailoring EFG structure and digestibility for safe, energy-dense diets for individuals with dysphagia. Full article

In the current study, bioactive-loaded hydrogels were developed with k-carrageenan (1%), and water was replaced with infusions of Urtica dioica L., which modulated the polymer chains to create more robust networks. Urtica dioica L. infusions were obtained with different infusion durations (5 or 10 min) or plant-to-water ratios (0.4, 1, or 2 g/100 mL). The hydrogels were characterized for stability by assessing the syneresis rate and textural and rheological attributes. To elucidate the influence of the infusion on the mechanisms of k-carragenan, temperature ramp tests were applied and FTIR spectra were acquired. Replacing water with Urtica dioica L. infusions for obtaining k-carrageenan hydrogels led to lower syneresis rates (3.34 ± 0.03% and 6.67 ± 0.33%), while the hydrogels showed increased hardness, but lower resilience and cohesiveness. The rheological parameters confirmed the reinforcement; higher G′ and gelling temperatures were registered compared to the reference. While FTIR spectra showed that the primary chemical backbone remained intact, the physicochemical changes indicate a strong physical synergy between nettle polyphenols and the κ-carrageenan chains. Of all samples, the highest antioxidant potential value of 94.66% was exhibited by the infusion obtained in 15 min with a ratio of plant material of 2/100 g. These findings demonstrate that plant-to-water ratios and infusion times are critical parameters for tuning the physical properties and biological efficacy of hydrogels for medical or food applications. Full article

Curcumin exhibits potent anti-obesity and anti-inflammatory activities; however, its therapeutic application is limited by poor aqueous solubility and low oral bioavailability. A curcumin-loaded chewable gel was developed to transform into an in situ gastric gel upon contact with gastric fluid after mastication. Curcumin solid dispersions (CUR-SDs) were prepared with Eudragit^® EPO (1:1–1:7, w/w) using the solvent evaporation method. The optimized formulation (1:3) markedly enhanced solubility and dissolution in acidic medium (0.1 N HCl, pH 1.2) compared with crystalline curcumin and physical mixtures. The optimized CUR-SD was subsequently incorporated into chewable gels composed of sodium alginate and κ-carrageenan, with calcium carbonate as a gas-forming agent. The formulations formed buoyant matrices under acidic conditions, exhibiting floating lag times of 21–215 s and sustaining drug release for up to 8 h. Increasing polymer content improved mechanical strength and modulated release kinetics. Among the tested formulations, F7 achieved the optimal balance between texture properties, floating behavior, and controlled-release performance. In LPS-stimulated RAW264.7 macrophages, curcumin, CUR-SD, and F7 showed comparable and potent anti-inflammatory activity (IC₅₀ = 4.12–4.84 µg/mL), outperforming indomethacin. In 3T3-L1 adipocytes, F7 significantly reduced lipid accumulation (~47%) in a concentration-dependent manner. These findings demonstrate that this transformable chewable in situ gelling platform is a promising gastroretentive strategy for improving the oral therapeutic efficacy of poorly soluble bioactive compounds for anti-obesity applications. Full article

In this study, a multicomponent composite film system based on alginate, chitosan, κ-carrageenan, agar, and Rapana venosa protein hydrolysate (RVPH) was developed, and the effect of RVPH incorporation (0–1.5%) on molecular interactions, microstructure, and functional performance was evaluated using FTIR, SEM, mechanical testing, optical analysis, and water-related measurements. FTIR results indicated that RVPH interacted with the polysaccharide matrix mainly through hydrogen bonding and ionic interactions without causing chemical degradation. SEM analysis revealed concentration-dependent microstructural changes, with smoother morphologies at low RVPH levels and increased roughness and heterogeneity at higher concentrations. These structural differences were reflected in the functional properties. All films exhibited high swelling and water solubility. Optical properties were significantly affected by RVPH. Mechanical properties exhibited a non-linear response, with numerical variations observed but no statistically significant differences (p > 0.05). The EDAS and SWARA methods were employed to determine the optimal incorporation level of RVPH in the film formulations. Among the RVPH-containing films, the formulation incorporating 1% RVPH was identified as the most suitable alternative. Full article