Polysaccharides

This study evaluated the effects of chitosan composite edible coatings with frankincense essential oil on microbial growth and strawberry quality. Four coatings were prepared using 1% and 3% chitosan aqueous solutions, with or without 1% (v/v) frankincense essential oil derived from Boswellia sacra. Fresh strawberries were coated with chitosan and chitosan–frankincense solutions and stored under controlled conditions for eight days. The physical properties of strawberries, such as color, texture, moisture content, pH, and total soluble solids, were evaluated throughout the storage period. Results indicated that neither chitosan nor chitosan–frankincense oil coatings significantly altered the physical properties of the strawberries, such as the color, pH, moisture content, total soluble solids, and hardness at each time point. However, a significant effect of time (2-way ANOVA, p < 0.05) was observed on pH, TSS, color and hardness characteristics of strawberries. All tested coatings effectively inhibited bacterial growth. The strawberries covered with 3% chitosan–frankincense oil coating had the lowest bacterial count (74 CFU/mL). The addition of frankincense to 1% of chitosan significantly reduced the number of bacteria by 1.6-fold. Additionally, chitosan–frankincense oil films significantly reduced the growth of E.coli compared to both the chitosan film and the control. These findings suggest that chitosan combined with frankincense oil can serve as an effective natural alternative for edible coating in food preservation, offering both antimicrobial benefits and quality retention during storage. Full article

Background: Liver fibrosis drives mortality in chronic liver disease, with effective and approved targeted therapies being an urgent unmet medical need. Natural polysaccharides are promising multitarget candidates, but a critical appraisal of the preclinical evidence for their translatability is lacking. Objective: This review systematically synthesizes the evidence on the efficacy, mechanisms, and methodological quality of preclinical studies investigating the antifibrotic potential of natural polysaccharides. Methods: Six databases were searched (inception to February 2025) for studies in experimental liver fibrosis models. The review followed PRISMA guidelines. Risk of bias and reporting quality were assessed using the SYRCLE (Systematic Review Centre for Laboratory Animal Experimentation) and ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines, respectively. Results: Eighty-eight studies on 44 polysaccharides were included. A major limitation was the predominant use of the carbon tetrachloride (CCl₄) rat model (54.5%). Despite this, polysaccharides showed consistent efficacy: collagen deposition was suppressed in 92.0% of studies, and serum alanine/aspartate aminotransferase (ALT/AST) were reduced in 100%. Mechanistically, inhibition of the transforming growth factor-beta (TGF-β)/Smad pathway (implicated in 60.2% of studies) and modulation of the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) pathway (15.9%) were the most common findings. However, methodological quality was low, with unclear allocation concealment (92.0%) and absent blinding (86.4%) being pervasive issues. Conclusions: This review confirms that natural polysaccharides consistently attenuate experimental fibrosis by modulating key pathways like TGF-β/Smad. Our key contribution is highlighting a critical disconnect: demonstrated efficacy is undermined by poor methodological rigor and the use of simplistic models. This gap represents a major barrier to clinical translation. Advancing these promising agents requires prioritizing chemical standardization, employing more relevant disease models, and adhering to rigorous reporting standards. Full article

This study focused on the incorporation of Piper betle L. essential oil (EO) into β-cyclodextrin (β-CD) and the subsequent incorporation of this complex into chitosan-based films with a beeswax coating. The objective of this study was to develop a hydrophobic, antibacterial bio-based film suitable for preservation applications. A total of four formulations were prepared: (1) chitosan film with no EO or β-CD, (2) chitosan film with β-CD only, (3) chitosan film with EO only, and (4) chitosan film with both EO and β-CD. The EO concentration was varied between 0, 0.5 and 1% (v/v) in the formulation, while β-CD was used at a concentration of 5% (w/v). The films were characterized using FTIR to analyze functional groups, SEM for surface morphology, contact angle to assess hydrophobicity, and tensile tests for mechanical properties. The results indicated significant changes in functional group characteristics and surface morphology across the different formulations. Beeswax coating enhanced the water impermeability and increased the hydrophobicity of the films, improving the contact angle from 59.93 ± 1.79° to 97.84 ± 0.77° and the mechanical strength from 0.28 ± 0.07 MPa to 24.49 ± 0.04 MPa. The antibacterial activity, assessed using the Kirby–Bauer method, showed that the EO concentration significantly inhibited the growth of Escherichia coli, with a maximum inhibition zone of 7.43 ± 0.60 mm observed at the highest EO concentration. These findings demonstrate that chitosan-based film modifications, incorporating both EO and β-CD, significantly improve the material properties and antibacterial activity, indicating its potential for food preservation applications. Full article

Conventional polycarboxylate superplasticizers (PCEs) suffer from uncontrollable adsorption, characterized by rapid initial uptake and limited subsequent release, which causes pronounced slump loss, particularly at elevated temperatures where hydration accelerates and dispersion efficiency declines. To overcome these limitations, we developed a series of chitosan-based upper critical solution temperature (UCST) responsive superplasticizers (Thermo-PCE_x, UCST = 40–42 °C) capable of temperature -adaptive dispersion during cement hydration. A vinyl-functionalized chitosan macromonomer (uCS-g-T₈) was synthesized by reacting cetyl polyoxyethylene glycidyl ether with chitosan, followed by methacrylate modification, and then copolymerized with acrylic acid and isopentenol polyoxyethylene ether to yield Thermo-PCE_x with tunable sugar-to-acid ratios. The polymers exhibited clear UCST-type phase-transition behavior in aqueous solution. When incorporated into cement paste, Thermo-PCE_x enabled continuous fluidity enhancement at 25 °C (<UCST), with increases of 43.6%, 52.9%, 62.3% and 63.6%, after 180 min for x = 0.5, 1, 1.5 and 2, respectively. Adjusting dosage and composition further regulated setting time, improved rheological stability, and enhanced mechanical strength. These findings demonstrate a viable pathway for designing bio-based, temperature-responsive superplasticizers with self-adaptive dispersibility for sustainable cement technologies. Full article

The present work investigates the effect of powdered lignocellulose from alfalfa straw obtained by a chemo-extrusion method, as well as its carboxymethylated derivative, on the physicomechanical properties and swelling behavior of vulcanizates based on nitrile butadiene rubber (NBR, BNKS-28 AMN grade). Carboxymethylation of lignocellulose was performed using microwave activation. The functional group composition of the modified lignocellulose was characterized by Fourier-transform infrared (FTIR) spectroscopy, which confirmed successful carboxymethylation and revealed a reduction in crystallinity. Thermogravimetric analysis (TGA) was used to determine the thermal stability of the swelling carboxymethylated fillers. The degree of crystallinity of the carboxymethylated swelling fillers was evaluated by X-ray diffraction (XRD). It was shown that the introduction of powdered lignocellulose and its carboxymethylated derivative into the rubber compounds lead to an increase in compound viscosity and prolong the optimum cure time, while having no effect on the scorch time, in a manner similar to that observed for the commercial product sodium carboxymethylcellulose (NaCMC). It has been shown that the introduction of powdered lignocellulose and its carboxymethylated derivative increases the tensile strength of the rubber and improves its resistance to the action of mineralized water compared with the samples containing NaCMC. It was also demonstrated that carboxymethylated lignocellulose exhibits enhanced sorption capacity comparable to that of NaCMC. Overall, carboxymethylation of lignocellulose derived from alfalfa straw significantly improves the stability and sorption characteristics of nitrile butadiene rubber composites. These findings indicate that carboxymethylated lignocellulose is a sustainable and effective alternative to industrial NaCMC for use as a functional filler in elastomeric materials. Full article

Pineapple processing generates substantial waste, which has the potential to be valorized according to circular economy principles. This study aimed to estimate the amount of waste generation from the pineapple industry and demonstrate its valorization by producing pectin-based hydrogels for fat replacement in reduced-fat sausages, in addition to cellulose-derived edible films for sausage casings. An analysis of the pineapple sector in Thailand, covering 2015–2024, revealed an average annual pineapple waste generation of 670,698 tons. The crude fiber content in pineapple waste was found to be 15–33%. In this study, pectin was successfully extracted using citric acid under microwave digestion for 10 min. Through the combination of extracted and commercial pectins, a hydrogel (fat replacer) could be formed following the incorporation of calcium residue in fish bone powder. Substituting this hydrogel for 25% fat in sausage recipes reduced fat content while improving textural properties and water-holding capacities. The reduced-fat sausage, wrapped with edible film made from gelatin and carboxymethyl cellulose (CMC) derived from pineapple waste, exhibited physicochemical stability, as evidenced by its unchanged color and pH during cold storage for 5 days. Storing this type of sausage within films containing CMC from pineapple waste exhibited superior antioxidative properties compared to those wrapped with commercial films. Our results indicated that polysaccharide residues in pineapple waste can be valorized to produce reduced-fat sausages and casings, supporting upcycling policies and waste management strategies. Full article

Paper-based analytical devices (PADs) were developed as low-cost tools for detecting chemical and biological compounds, commonly fabricated from cellulose derived from plant biomass. Bamboo, a fast-growing and abundant plant with high cellulose content (40–50%), was investigated as a substrate source. In this study, the selection of bamboo was based on its rapid growth cycle and the abundance of parenchyma cells that facilitated nanofibrillation compared to cellulose fibers from softwood or hardwood. Cellulose fibers were extracted from black bamboo (30 and 60 mesh) using mechanical and acid hydrolysis methods. The mechanical method employed ultrasonication to obtain nanocellulose, while the acid hydrolysis method used strong acids, i.e., H₂SO₄. The resulting nanocellulose papers exhibited variations in contact angle, porosity, and transmittance that directly affected their permeability and fluid flow behavior. The results indicated that the mechanical method, which extracted nanocellulose from parenchyma cells, yielded more consistent thermophysical and mechanical properties suitable for paper-based biosensors. The fabricated nanocellulose papers were tested as PADs for colorimetric detection of dopamine and hydrogen peroxide. Based on the literature comparison, their sensing performance, including sensitivity, linearity, limit of detection (LOD), and limit of quantification (LOQ), was comparable to other nanocellulose-based papers, indicating the potential of bamboo-derived nanocellulose as a sustainable substrate for PADs. Full article

Agricultural leftovers from oilseed crops represent an underutilized lignocellulosic resource for integrated biorefinery. In this work, rapeseed straw (RS) and sunflower stalk (SS) were evaluated as raw materials for the simultaneous recovery of hemicelluloses, lignin, and cellulose-rich fibers. Direct soda pulping (20% NaOH, 160 °C, 45 min) or a combination of soda pulping with water pretreatment or alkaline extraction (water or 2% NaOH, 110 °C, 40 min) were the methods used in the process. Acid precipitation was used to remove lignin from the process fluids, whereas ethanol was used to separate hemicelluloses. FTIR spectroscopy, HPLC of acidic hydrolysates, and chemical composition analysis were used to analyze solid fractions and recovered biopolymers. The combination alkaline extraction–soda pulping produced the greatest material removal: 55% for RS and 70% for SS. Xylan was the main component of the isolated hemicellulose fraction: 44.86% for RS and 40.09% for SS. Paper sheets produced from the resulting pulps exhibited tensile strength indices of 35–55 N·m/g and burst indices of 1.1–2.4 kPa·m²/g, meeting requirements for hygiene and fluting packaging papers. These results prove that RS and SS are suitable feedstocks for integrated, multi-stream biorefinery, enabling the concurrent production of paper-making fibers and value-added biopolymers. Full article

The growing demand for fresh fruit, coupled with high postharvest losses, highlights the need for sustainable and effective preservation technologies. In this context, polymeric biocoatings are emerging as a promising alternative to conventional synthetic packaging, thanks to their biodegradability, film-forming capacity, and potential to incorporate bioactive compounds. This review article summarizes recent advances in the development of coatings based on polysaccharides, proteins, and nanomaterials, analyzing their physicochemical, functional, and sensory properties, and the main conventional and emerging application methods used in fresh fruit. It also highlights the role of phenolic compounds and essential oils as antioxidant and antimicrobial agents, along with the valorization of agro-industrial by-products under circular economy schemes. Finally, it discusses the challenges associated with standardization, industrial scaling, and consumer acceptance, proposing future perspectives aimed at designing multifunctional systems that extend the shelf life and improve the quality of fresh products, in line with environmental sustainability objectives. Unlike recent reviews, this work unifies structure–function relationships with quantitative comparisons of coating performance across fruits. It further contributes a critical evaluation of emerging application technologies and their technological and regulatory readiness, offering a distinctly more integrated perspective. Full article

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