Polysaccharides

Chondroitin sulfate is a glycosaminoglycan polysaccharide, playing key roles in a plethora of physiopathological processes typical of higher animals. The position of sulfate groups within CS disaccharide subunits composing the polysaccharide chain is able to encode specific functional information. In order to expand such a “sulfation code”, access to non-natural CS variants and mimics thereof can be pursued. In this context, an interesting topic concerns phosphorylated analogs of CS polysaccharides, as the replacement of sulfate groups with phosphates can lead to unreported activities of phosphorylated CS. In light of this, the phosphorylation reaction of a microbial-sourced, unsulfated chondroitin polysaccharide with phosphoric acid is reported in the present study, testing different microwave irradiation conditions and comparing them with conventional heating procedures. The obtained products were subjected to a detailed characterization, in terms of chemical structure and hydrodynamic properties, by 1D- and 2D-NMR spectroscopy and HP-SEC-TDA analysis, respectively. The characterization study showed how different reaction conditions can not only influence the regioselectivity and degree of phosphorylation but also trigger the formation of phosphate diester functionalities acting as cross-linkers between polysaccharide chains. The results from the screening presented in this work could be interesting for any research devoted to the regioselective phosphorylation of a polysaccharide. Full article

Brown seaweeds are marine bioresources rich in bioactive compounds such as carbohydrates, proteins, pigments, fatty acids, polyphenols, vitamins, and minerals. Among these substances, brown algae-derived polysaccharides (alginate, fucoidan, and laminarin) have promising industrial prospects owing to their distinctive structural features and diverse biological activities. Consequently, processing technologies have advanced substantially to address industrial requirements for biopolymer quality, cost-effectiveness, and sustainability. Over the years, significant progress has been made in developing various advanced methods for the sake of extracting, purifying, and structurally characterizing polysaccharides. Aside from that, numerous studies reported their broad spectrum of biological activities, such as antioxidant, anti-inflammatory, anticoagulant, and antimicrobial properties. Furthermore, these substances have various industrial, pharmaceutical, bioenergy, food, and other biotechnology applications. The present review systematically outlines the brown algae-derived polysaccharides treatment process, covering the entire value chain from seaweed harvesting to advanced extraction methods, while highlighting their biological activities and industrial potential as well. Full article

A series of biocomposites were elaborated by incorporating cellulose fibers, obtained from raw alfa plant, into a new polyurethane (PU) matrix synthesized from jojoba oil. The cellulose content was adjusted between 0% and 50%. To examine their properties, several characterization methods were employed. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses confirmed that the extracted cellulose and the polyurethane matrix have high interfacial adhesion. Thermal stability was assessed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). They indicate that the composites remained thermally stable in air up to 265 °C and exhibited glass transition temperatures (Tg) in the range of −38 to −7 °C, depending on the fiber percentage inside the polyurethane-based biocomposite. The corresponding mechanical properties increased with the addition of cellulose, reaching optimal improvement at 40% fiber content. Full article

The agro-industrial valorization of citrus waste represents a promising avenue to employ underutilized bioresources. This research investigated the potential of the peels of BARI malta 1 (sweet orange), a widely grown variety in Bangladesh, as a viable and new source for pectin extraction. Pectin is a polysaccharide, having extensive applications in the pharmaceuticals, cosmetics, and food business as a thickening, texturizer, emulsifier, gelling agent, and stabilizer. This study investigated the optimum extraction conditions for maximum yield, characterization, and physicochemical properties of the obtained pectin and compared the results with the pectin obtained from other sources. Comprehensive characterization through Fourier-Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), and Field Emission Scanning Electron Microscopy (FESEM) confirmed the structural identity, crystallinity, thermal stability, and morphological features of the extracted pectin. Physicochemical properties, including moisture content, ash content, equivalent weight, methoxyl content, and degree of esterification, indicate the suitability and superiority of the extracted pectin for industrial applications. This research approach not only supports eco-friendly processing of citrus waste but also opens avenue for circular economy initiatives in Bangladesh. Full article

Microbial polysaccharides are promising components for wound-care products. This study reports the development of wound-healing antimicrobial hydrogels, based on pullulan from Aureobasidium pullulans, combined with mesenchymal cell-derived conditioned medium. Structural characterization of pullulan was confirmed by FTIR and NMR. Twenty-three formulations containing pullulan, chitosan, gelatin, citric acid, and antimicrobial agents were prepared. Physicochemical screening identified optimal hydrogels: No. 22 (1.2% pullulan, 1.2% chitosan, 0.2% citric acid, 2.4% gelatin, 0.1% conditioned medium, 0.4% glutaraldehyde) and No. 23 (2.4% pullulan, no chitosan, the remaining components identical to those in No. 22). Both exhibited pH values of 5.34 and 5.49, moisture content of 92%, swelling capacities of 175% and 213%, and dynamic viscosity between 58–120 mPa·s. Cytotoxicity testing with human mesenchymal stem cells showed no significant toxicity, with both hydrogels supporting cell adhesion and proliferation. Antimicrobial assays demonstrated inhibitory activity against Staphylococcus aureus and Escherichia coli for both formulations; only hydrogel No. 23 inhibited Pseudomonas aeruginosa. In vitro scratch assays revealed that hydrogel No. 23 significantly promoted fibroblast migration, achieving 30.25% scratch closure after 24 h. The developed formulations combine favorable physicochemical properties with antimicrobial efficacy and regenerative potential, supporting further evaluation as advanced wound-healing and anti-burn dressings. Full article

The demand for clean-label functional foods has increased interest in natural polysaccharides with health benefits. Acemannan, an O-acetylated glucomannan from Aloe vera, possesses antioxidant, immunomodulatory, and prebiotic activities, but its performance in fat-based systems is not well understood. This study examined the incorporation of acemannan into dark chocolate at 1% and 5% (w/w) and its effects on physicochemical, rheological, antioxidant, and sensory properties. Particle size distribution remained within acceptable limits, though the 5% sample showed a larger mean size and broader span. Rheological tests confirmed shear-thinning behavior, with the higher concentration increasing viscosity at low shear and reducing it at high shear. Antioxidant activity measured by the DPPH assay showed modest improvement in enriched samples. Consumer tests with 30 panelists indicated a strong preference (89%) for the 1% formulation, which maintained a smooth mouthfeel and balanced sensory characteristics, while the 5% sample displayed more fruity and earthy notes with lower acceptance. GC–MS analysis revealed altered volatile profiles, and FTIR spectroscopy confirmed acemannan stability in the chocolate matrix. These findings demonstrate that acemannan can be incorporated into dark chocolate up to 1% as a multifunctional, structurally stable polysaccharide ingredient without compromising product quality. Full article

Smart packaging is an alternative that may not only replace plastic containers, but also enable food quality monitoring. In this study, an innovative packaging system was developed using a starch-chitosan polymer matrix, infused with rosemary essential oil (REO) as an antimicrobial agent, and betalain extract as a food quality indicator. Betalain extract, derived from beet waste, can change color with pH, making it a useful natural indicator for monitoring food freshness. This packaging system is beneficial for foods that produce metabolites related to degradation, which alter pH and allow for the visual detection of changes in product quality. The objective of this work was to develop a smart packaging system with betalains and rosemary essential oil (REO) to extend food shelf life and monitor quality during storage. REO demonstrated antimicrobial activity, but its effect did not differ significantly among the microorganisms tested. On the other hand, the betalain extract (35.75% BE v/v) completely inhibited the growth of Listeria innocua and Salmonella spp. at concentrations of 50% (v/v; 0.82 ± 0.04 mg betalain/g), showing its potential as an antimicrobial agent. The interactions between chitosan and betalains were primarily associated with electrostatic interactions between the positively charged amino groups of chitosan and the negatively charged carboxyl groups of betalains. In contrast to starch, these interactions could result from interactions between the C=O groups of betalain carboxyls and water, which, in turn, interact with the hydroxyl groups of starch through hydrogen bonding. Despite the results obtained in this study, certain limitations need to be addressed in future research, such as the variability in antimicrobial activity among different bacterial strains, which could reveal differences in the efficacy of betalains and essential oils against other pathogens. Full article

This study explores a multi-resource approach for extracting and characterizing l-rhamnose-rich polysaccharides from nine natural biomasses, including green macroalgae (Ulva spp.), sumac species (Rhus spp.), and agro-industrial by-products such as sea buckthorn and sesame cakes. Hot-water and alkaline extractions were performed by biomass type, and the resulting fractions were analyzed using biochemical assays, monosaccharide profiling (HPAEC/PAD and GC/MS-EI), FTIR, and antioxidant activity tests. Extraction yields ranged from <1% in sea buckthorn residues to 15.48% in Ulva spp., which showed the highest recovery. l-rhamnose enrichment varied across biomasses: the highest proportions were found in Ulva extracts and Rhus semialata galls (PRS), reaching up to 44% of total sugars by HPAEC/PAD and 58% by GC/MS-EI. Antioxidant activities also differed markedly. In DPPH assays, the most active extracts were those from sea buckthorn berry cake (PTBA), Rhus coriaria seeds (PRC), and commercial sea buckthorn powder (PPA), with IC₅₀ values of 32, 43, and 42 µg/mL, respectively. Hydroxyl-radical inhibition was also substantial, reaching 83.0% for PTBA, 79.4% for PRC, and 79.9% for Ulva lactuca at 1 g/L, compared with 97.5% for ascorbic acid. These results highlight specific biomasses as promising dual sources of l-rhamnose and natural antioxidants for valorization within a circular bioeconomy. Full article

Arabinoxylans (AX) are polysaccharides capable of forming covalent gels stable under variations in pH and temperature. They are fermentable by the colonic microbiota, making them appropriate carriers for colon-targeted oral drug delivery, including insulin. This study aimed to fabricate covalent AX nanoparticles loaded with insulin (NPAXI) using a 0.25 (AX/insulin) mass ratio and to evaluate their colon-targeted capacity to improve glycemic control in diabetic rats. In parallel, we assessed gut microbiota modulation as a secondary outcome, derived from the prebiotic fermentation of AX, considered an additional benefit. NPAXI, produced by coaxial electro spraying, displayed a mean diameter of 661 nm, a zeta potential of −31 mV, and high insulin encapsulation efficiency. Bioassay demonstrated that a single oral NPAXI dose restored normoglycemia for 9 h, starting 15 h post-administration. Gut microbiota analysis revealed that while insulin alone increased Lactobacillaceae, it failed to suppress Enterobacteriaceae. NPAXI treatment, however, promoted beneficial taxa such as Muribaculaceae and Prevotellaceae and reduced proinflammatory families like Desulfovibrionaceae and Helicobacteraceae. These microbial shifts paralleled the improved glycemic profile, suggesting a synergistic interaction between AX and insulin in reestablishing gut microbial homeostasis and metabolic regulation. Overall, NPAXI represents a promising strategy for colon-targeted oral insulin delivery, offering additional microbiota-modulating benefits. Full article

This study investigates the emulsifying capacity (EC), emulsion stability (ES), and oleogel-forming potential of galactomannan (GM) esters modified with decanoic (GD) and palmitic (GP) fatty acids at low (L) and high (H) degrees of esterification (DE) (GDL, DE 0.37; GDH, DE 0.71; GPL, DE 0.47; GPH, DE 0.57). Oil-in-water (O/W) emulsions (6, 8, and 10% w/v) of native GM and GM esters were prepared and characterized for droplet size, ζ-potential, and rheological behavior. Esterified GMs demonstrated improved EC compared to native GM, especially at higher concentrations and lower DE. All emulsions exhibited non-Newtonian and pseudoplastic behavior, with the GDH and GPL samples showing gel-like viscoelastic profiles (G′ > G″). Emulsions were freeze-dried to form oleogels, which were then analyzed for oil-binding capacity (OBC), hardness, chemical interactions (FTIR-ATR), and microstructure (SEM). The GDH and GPL oleogels exhibited higher OBC (59–73%) and lower hardness, which can be attributed to denser polymer–oil networks and enhanced hydrophobic interactions. SEM analysis further confirmed that esterification improved the microstructural integrity of emulsion-templated oleogels. These findings support the potential of mesquite GM esters as amphiphilic oleogelators for the formulation of structured lipid systems, offering valuable applications in food and pharmaceutical industries seeking solid fat alternatives. Full article

Current resource and processing constraints on conventional chitin production call for novel sources and more sustainable methods for its production. Herein, domestic cricket (Acheta domesticus L.) meal obtained from supercritical CO₂ oil extraction was investigated as a viable source of chitin via a one-pot approach using acidic (choline chloride: glycerol, CCG) and alkaline (potassium carbonate: glycerol, KG) deep eutectic solvents (DESs). The chitin samples obtained were compared with those obtained using conventional acid-alkaline extraction (CE) and commercial crab shell chitin (CS chitin) by robust characterization of their composition and physicochemical properties employing color, FTIR, XRD, XPS, and SEM analysis. The results showed that KG DES and recovered KG DES exhibited high demineralization and deproteinization capacity, producing chitin with high purity, α-chitin form, high acetylation degree (>77%), crystallinity (crystallinity index > 81%), and micro-fibrous morphology closely similar to those of CE chitin and CS chitin. Whereas CCG DES demonstrated excellent demineralization, it was less effective at deproteinization, leading to chitin with lower purity and crystalline properties. Together, the results demonstrated that cricket meal could be an alternative source of chitin, while KG DES one-pot extraction holds strong potential as a sustainable and eco-friendly approach for obtaining commercial-grade chitin. Full article

In recent years, the sustained and even increasing interest in the development and application of novel composite materials based on the polysaccharide bacterial cellulose (BC) has been driven by the accumulation of experimental data and the emergence of analytical reviews that narratively summarize these findings. This review presents a comparative and critical analysis of various approaches to the fabrication of BC-based composites. Among them, in situ biosynthesis is highlighted as the most promising strategy. In this approach, different additives are introduced directly into the culture medium of BC-producing microorganisms, enabling the formation of materials with different mechanical and physicochemical properties. Such a method also allows imparting to the composites a range of properties that BC itself does not possess, including antibacterial and enzymatic activity, as well as electrical conductivity. During the so-called “cell weaving” stage, performed by BC-producing microorganisms, diverse substances and microorganisms can be incorporated into the cultivation medium. By varying the concentrations of the introduced compounds, their ratios to the synthesized BC, and by employing different BC-producing strains and substrates, it becomes possible to regulate the characteristics of the resulting composites. Special attention is given to the role of various polysaccharides that are either introduced into the medium during BC biosynthesis or co-synthesized alongside BC within the same environment. Depending on the mode of incorporation of these additional polysaccharides, the resulting materials demonstrate variations in Young’s modulus and tensile strength. Nevertheless, they almost invariably exhibit a decreased degree of BC crystallinity within the composite structure and an enhanced water absorption capacity compared to the pure polymer. Full article

The use of biodegradable polymers in slow-release NPK fertilizers is gaining prominence for reducing overdosing, minimizing nutrient loss, and enhancing efficiency. This study prepared modified and unmodified thermoplastic starch (TPS) systems via extrusion, incorporating collagen and potassium phosphate. Controlled-release nutrient systems utilizing nitrogen from an organic source were developed and characterized. The materials were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measurements, and biodegradability in the soil. The biodegradability of the polymeric matrix was evaluated through mass loss, with up to 78.9% degradation observed after 60 days for TPS-based systems containing collagen. Structural modifications in the TPS matrix led to changes in crystallinity and hydrophilicity, which directly influenced degradation rates. The nutrient release effect was assessed by monitoring the growth of chili pepper seedlings over 15 days. Seedlings grown in soil containing polymeric systems with 20% collagen or 6.2% urea reached average heights between 5.2 and 7.8 cm, compared to 5.0 cm for the unmodified TPS and 0 cm in treatments with pure urea, which caused seedling mortality. The polymeric systems containing collagen exhibited superior performance as a sustainable nitrogen source, ensuring a slower and more controlled release while yielding positive outcomes for early plant development. Full article

The mechanical, thermal, physicochemical and structural properties of a thermoplastic cassava starch obtained by a twin-screw extrusion process were evaluated, using glycerol and isosorbide as plasticizers at different concentrations (30, 35 and 40% by weight) and storage times (1, 15 and 30 days) under controlled conditions of relative humidity of 47 ± 2% and temperature of 25 ± 2 °C. The results obtained show a decrease in tensile strength and modulus of elasticity and an increase in elongation in the initial measurements, suggesting that, in both cases, a plasticization phenomenon via absorption of humidity predominated in short times, while at prolonged times, a rigidification of the material occurred due to the generation of a retrogradation process. Likewise, a higher tensile strength and lower elongation were found in the materials plasticized with isosorbide. Finally, it was observed that the retrogradation phenomenon was more evident in the thermoplastic starch samples made with glycerol, and that the starches plasticized with isosorbide had lower moisture absorption, higher crystallinity and a predominantly Eh-type crystalline pattern, related to greater stability over time. Full article

The global aquaculture industry faces a number of challenges, including the risk of infection spreading in closed aquatic ecosystems. Since 1942, vaccination has become a mainstream approach in fish cultivation. However, the immune system of cold-blooded organisms differs significantly from that of mammals, which must be taken into account when developing vaccines for aquaculture. Modern technology employs delivery systems for antigens to protect them from degradation in the water and the digestive tract. Packaging the antigen into a biodegradable structure protects the protein or target gene from degradation and enhances antigen delivery to immune cells. The combination of chitosan and alginate is widely used for the development of various types of nano- and microcarriers. New vaccines based on these polysaccharides are more effective, increasing survival rates in some fish species by up to 100% compared to 20% in the control group. However, the correlation between the observed effects and the physicochemical characteristics of the polysaccharides/carriers, and the mechanisms of their action, remains unclear. This review summarizes and analyzes the data on the use of chitosan and alginate in aquaculture vaccines. Particular focus is given to the physicochemical properties and sources of the polysaccharides, and their potential implementation in aquaculture vaccination practices. Full article

Hydrogels based on gelatin–chitosan mixtures have great potential for practical application in the development of new materials in food technology and biomedicine. This study examines the effect of chitosan on the gelling properties, rheological, and structural characteristics of fish gelatin type A hydrogels in the acidic pH range of 3.2–3.9. It was shown that an increase in the chitosan-to-gelatin mass ratio up to 0.15 resulted in a growth in the hydrogel thermal stability and an increase in the elastic modulus, hardness, and yield stress. The structural strength of the fish gelatin–chitosan hydrogel increased due to the strengthening of the binding zones in the fish gelatin gel network in the presence of chitosan. According to scanning electron microscopy, the supramolecular microstructure of the gels demonstrated a significant compaction upon the addition of chitosan to fish gelatin. UV and IR spectroscopy data, as well as changes in zeta potential, showed the formation of supramolecular complexes of fish gelatin with chitosan as a result of hydrophobic interactions between biomacromolecules and the establishment of hydrogen bonds; in this case, electrostatic interactions between macromolecules of fish gelatin and chitosan are practically absent in the acidic pH region. The ability to form supramolecular complexes of different compositions at different mass ratios of polysaccharide-to-fish gelatin makes it possible to obtain hydrogels with high gelling properties, strength, elasticity, and thermal stability comparable to hydrogels of mammalian gelatin. Full article

This study developed a sustainable super-disintegrant derived from Dioscorea hispida Dennst. var. hispida starch for use in immediate-release pharmaceutical tablets. Native starch (NS) was extracted and chemically modified via carboxymethylation to obtain carboxymethyl starch (CMS), followed by phosphate cross-linked to yield modified starch (MS). Physicochemical properties demonstrated that MS exhibited superior water uptake, swelling, and viscosity compared to NS and CMS. Scanning Electron Microscopy (SEM) revealed smaller and more uniform granules in MS, confirming enhanced structural modification. Preliminary tablet trials with dicalcium phosphate showed that 4% w/w MS achieved the fastest disintegration (16.5 s). In paracetamol tablets prepared by wet granulation, MS significantly improved hydration and disintegration performance relative to NS and CMS. Although commercial sodium starch glycolate (SSG) provided slightly faster disintegration, dissolution profiles of tablets containing MS and SSG were statistically equivalent (f₁ = 7, f₂ = 63), confirming comparable efficacy. Porosity analysis using synchrotron radiation X-ray tomography (SR-XTM) indicated that wet-granulated tablets possessed higher intra- and inter-granular porosity than direct compression tablets, facilitating rapid water penetration and disintegration. In contrast, denser direct compression tablets exhibited greater friability and lower mechanical integrity. Modified Dioscorea hispida starch demonstrated excellent disintegration efficiency, eco-friendliness, and local availability, presenting a promising natural alternative to synthetic super-disintegrants in immediate-release tablet formulations. Full article

Pediatric drug delivery presents unique challenges due to physiological and pharmacological differences across age groups, requiring specialized formulation approaches beyond simple dose adjustments of adult medications. This review synthesizes recent advances in polysaccharide-based pediatric drug delivery and highlights novel findings that may accelerate clinical translation. It summarizes how chitosan, alginate, hyaluronic acid, dextran, modified starches, and other polysaccharides are engineered into nanoparticles, hydrogels, films, and orodispersible/mini-tablet formulations to improve stability, bioavailability, taste masking, and controlled release across neonates to adolescents. These systems can accommodate developmental variations in absorption, distribution, metabolism, and excretion processes across pediatric subpopulations, with particular emphasis on oral and alternative administration routes. Evidence supporting unexpectedly high acceptability of mini-tablets, successful integration of modified polysaccharides in 3D-printed personalized low-dose therapies, and the emergence of blood–brain barrier-penetrating and RGD-functionalized polysaccharide nanocarriers for pediatric oncology are emphasized as novel, clinically relevant trends. This review also addresses regulatory considerations, safety profiles, and future perspectives. By integrating developmental insights with innovative formulation strategies, polysaccharide polymers offer promising solutions to improve medication adherence, safety, and efficacy across the pediatric age spectrum. Full article