Polysaccharides

In agriculture, the use of fructans has gained relevance due to their ability to improve plant immunity and resistance to pathogens. However, many studies use high-purity fructans, which makes their application more expensive. In this work, the efficacy of two agave fructans, one food grade from Agave tequilana Weber var. Azul (FT) and the other obtained by semi-craft extraction from A. cupreata (FC) were evaluated in comparison with reagent-grade inulin from dahlia tubers. The effectiveness of their defense response against Phytophthora capsici infection in tomato (Solanum lycopersicum L.) was analyzed by evaluating defense mechanisms, including lignin deposition, hydrogen peroxide (H₂O₂) accumulation, and β-1,3-glucanase and peroxidase activity. The results indicated that foliar application of both fructans showed protection against infection, reducing disease incidence and severity. FT fructans at lower concentration (0.5 g/L) showed the highest protection, followed by FC, while dahlia inulin showed lower effectiveness. An early and progressive accumulation of H₂O₂ was observed in fructan-treated plants, in contrast to the late increase in untreated infected plants. Also, peroxidase activity was higher in the fructan treatments, suggesting a more efficient defense response. Although lignin deposition was not directly correlated with protection against P. capsici, fructans showed potential as resistance inducers. Given their low cost, easy extraction, and zero environmental impact, agave fructans represent a viable alternative for crop protection in sustainable agricultural systems. This study opens the door to their validation in the field and their application in other economically important crops, contributing to biological control strategies with less dependence on agrochemicals. Full article

This study explored the functional and pharmaceutical properties of native and modified starches derived from rice bean (Vigna umbellata) using physical (pregelatinization) and chemical (phosphorylation, carboxymethylation) modifications. Native starch (NRBS) exhibited a 27.5% amylose content. Modifications significantly influenced physicochemical characteristics. Swelling power increased from 12.25 g/g in NRBS to 16.34 g/g (pregelatinized, PGRBS) and 18.91 g/g (carboxymethylated, CMRBS), while solubility reached 53.12% in CMRBS. X-ray diffraction study estimated degrees of crystallinity of 26.5%, 19.4%, 22.8%, and 14.5% for NRBS, PGRBS, phosphate crosslinked (CLRBS), and CMRBS, respectively. Oil absorption capacity was highest in CMRBS (1.67 g/g), while its free swelling capacity reached 6.12 g/g at 37 °C. In vitro digestibility showed resistant starch (RS) contents of 11.31%, 5.49%, 17.38%, and 21.65% for NRBS, PGRBS, CLRBS, and CMRBS, respectively. Flowability and compressibility analysis demonstrated that CLRBS had the best flow (Carr’s Index: 12.16%, Hausner ratio: 1.14), while CMRBS exhibited superior tablet hardness across compression forces. These findings highlight rice bean starch, particularly in its modified forms, as a sustainable and multifunctional excipient and ingredient for food and pharmaceutical applications. Full article

Nowadays, the use of materials from renewable resources, such as agricultural waste and forest residues, has increased. In this work, industrial waste recovered from a recycled paper/cardboard company was mechanically refined to obtain ligno-cellulosic microfibers (LCMFs). The obtained LCMFs were well characterized and chemically modified in situ together with natural rubber through silanization. The effect of in situ silanizated LCMFs, by using (3-triethoxysilylpropyl) tetrasulfide (Si69) as a silane coupling agent, on natural rubber (NR) compound properties was studied. The NR compound with silanizated LCMFs at 2.5 phr of Si69 (NR MF Si2) increased NR stiffness significantly. For example, the 300% modulus of NR MF Si2 was around 9 units higher than that of NR. The physical–mechanical properties, crosslink density, curing behavior, infrared spectroscopy, and microscopy of the compounds were studied to confirm the in situ silanization of the microfibers and its reinforcement effect on the NR matrix. The storage modulus (E′) obtained from Dynamic Mechanical Analysis suggested that the silanizated samples presented an uneven crosslinking, but it was enough to stiffen the NR chains. Full article

Starch particles (SPs) were extracted from underutilized wild yam (Dioscorea remotiflora) tubers using two methods: (1) acid hydrolysis (AH) alone and (2) acid hydrolysis assisted by ultrasound (AH-US). The SPs were chemically modified through esterification (using acetic anhydride [AA] and lauroyl chloride [LC]) and crosslinking (with citric acid [CA] and sodium hexametaphosphate [SHMP]). They were subsequently characterized by their yield, amylose content, and structural and physical properties. The yield of particles was 17.5–19.7%, and the residual amylose content was 2.8–3.2%. Particle sizes ranged from 0.46 to 0.55 µm, which exhibited mono-modal and bi-modal distributions for AH and AH-US treatments, respectively. Following chemical modification, yield notably increased, especially with substitution by LC (33.6–36.5%) and CA (32.6–38.7%). Modified SPs exhibited bi-modal particle distributions with micro- and nanoparticles and variable peak intensities depending on the chemical compound used. Unmodified SPs displayed irregular morphologies, showing disruptions (AH) or aggregation (AH-US). Chemical substitutions altered morphologies, leading to amorphous surfaces (CA: AH), clustering (LC), or fragmentation into smaller particles (SHMP) under AH-US treatment. FT-IR analysis indicated a decrease in hydroxyl groups’ peak area (A(-OH)), confirming the substitution of these groups in the starch structure. Crosslinking with CA resulted in the highest degree of substitution (AH: 0.43; AH-US: 0.44) and melting enthalpy (ΔH_f: 343.0 J/g for AH-US), revealing stronger interactions between SPs from both methods. These findings demonstrate that the extraction treatment of D. remotiflora SPs and the type of chemical modifier significantly influence the properties of SPs, underscoring their potential applications as natural biocarriers. Full article

This study aims to investigate the differences in the effects of spraying and immersing methods on edible coatings for halved and pitted plums. Earlier studies have shown that these biodegradable packaging materials can preserve the quality and safety of fruits for an extended shelf life. Halved and pitted plums (variety Stanley) were treated with chitosan and rosehip oil edible coating emulsions by spraying and immersing methods. The treated series were analyzed by physical, physicochemical, microbiological, and sensorial methods during refrigerated storage for nine days, until the onset of microbiological spoilage. At the beginning of the storage, there was a visible difference between the differently treated samples. The untreated series showed the fastest browning. The emulsion-sprayed samples presented the least changes in color, shape, and volume. A weaker effect of the immersion technique can be explained by a deep standing of the fruits in a treating solution or emulsion. Some of the immersed samples have an aqueous texture and received a smaller sensory rating. The advantages and disadvantages of the methods need further investigation, but on a production scale, spraying can guarantee uniform batches. In laboratory circumstances, immersion is an easier method that does not need expensive and difficult-to-use equipment and gives good results. Full article

The search for sustainable, economically viable, and effective plant protection strategies against pathogenic bacteria, fungi, and viruses is a major challenge in modern agricultural practices. Chitosan (CS) is an abundant cationic natural biopolymer known for its biocompatibility, low toxicity, and antimicrobial properties. Its potential use in agriculture for pathogen control is a promising alternative to traditional chemical fertilisers and pesticides, which raise concerns regarding public health, environmental protection, and pesticide resistance. This study focused on the preparation of chitosan nanoparticles (CS-NPs) through cross-linking with organic molecules, such as tannic acid (TA). Various formulations were explored for the development of stable nanoscale particles having encapsulation capabilities towards low compounds of varying polarity and with potential agricultural applications relevant to plant health and growth. The solution properties of the NPs were assessed using dynamic and electrophoretic light scattering (DLS and ELS); their morphology was observed through atomic force microscopy (AFM), while analytical ultracentrifugation (AUC) measurements provided insights into their molar mass. Their properties proved to be primarily influenced by the concentration of CS, which significantly affected its intrinsic conformation. Additional structural insights were obtained via infrared and UV–Vis spectroscopic measurements, while detailed fluorescence analysis with the use of three different probes, as model cargo molecules, provided information regarding the hydrophobic and hydrophilic microdomains within the particles. Full article

This study systematically investigated the oxidation of chitosan using the TEMPO/NaClO/NaBr catalytic system under varying experimental conditions, namely temperature, reaction time, and pH, in order to optimize the oxidation process. Response surface methodology (RSM) was employed to determine the optimal parameters for maximizing the efficiency of the reaction. The structural modifications to the chitosan following oxidation were confirmed using Fourier-transform infrared spectroscopy (FTIR), alongside additional analytical techniques, which validated the successful introduction of carbonyl and carboxyl functional groups. Solvent-cast films were prepared from both native and oxidized chitosan in order to evaluate their functional performance. The antibacterial activity of these films was assessed against Gram-negative (Salmonella) and Gram-positive (Streptococcus faecalis) bacterial strains. The oxidized chitosan films exhibited significantly enhanced antibacterial effects, particularly at shorter incubation periods. In addition, antioxidant activity was evaluated using DPPH radical scavenging and ferrous ion chelation assays, which both revealed a marked improvement in radical scavenging ability and metal ion binding capacity in oxidized chitosan. These findings confirm that TEMPO-mediated oxidation effectively enhances the physicochemical and bioactive properties of chitosan, highlighting its potential for biomedical and environmental applications. Full article

The present study aimed to develop biodegradable films formulated with pectin/carboxymethyl cellulose (CMC) and cinnamon essential oil, investigating the effects of CP treatment time on the properties of the films. The developed films were used as packaging to evaluate the shelf life of chicken meat. Biodegradable films were produced from a film-forming solution containing pectin/CMC, glycerol (30%), and cinnamon essential oil (2%). All formulations included the essential oil, and the control group corresponded to the film that was not subjected to CP treatment. The CP treatments were applied at 22.5 L/min, 20 kV, and 80 kHz for 10, 20, and 30 min. The results showed that increasing CP treatment time led to a progressive reduction in apparent viscosity, indicating improved homogeneity of the polymer system. Hydrophobicity increased with treatment time, as shown by a higher contact angle (from 51.15° to 62.38°), resulting in lower water solubility. Mechanical properties were also enhanced, with tensile strength rising from 3.29 MPa to 6.74 MPa after 30 min of CP. Biodegradability improved with treatment time, reaching 99.51% mass loss after 15 days for the longest exposure. Films produced from the solution treated for 30 min (FCP30) were most effective in extending the shelf life of chicken breast fillets, reducing lipid oxidation (TBARS: 61.9%), peroxide content (58.7%), and microbial spoilage (TVB-N: 59.2%) compared to the untreated film. Overall, the results highlight the importance of CP treatment time as a key factor in enhancing film performance, supporting its application in sustainable active packaging. Full article

The development of materials based on chitosan and polyesters that possess thermoplastic, biocompatible, and biodegradable properties is a perspective for additive technologies in biomedicine. Research on obtaining such compositions is constrained because the polysaccharide content does not exceed 5 wt.%, which cannot ensure effective tissue regeneration. Herein, we propose a method for obtaining thermoplastic block copolymers based on chitosan and poly(ε-caprolactone) by ultrasonic irradiation of a homogeneous solution of a homopolymer mixture in dimethyl sulfoxide as a common solvent, achieving a yield of 99%. The distinctive feature of the method is the interaction between the components at the molecular level and provides obtaining copolymers at any component ratio. SEM images revealed a homogeneous structure without structural defects in both solvent-cast films and extruded filaments. The block copolymers were characterized by high mechanical property tensile strength of up to 60–70 MPa and elasticity of up to 35% for films and 25–40 MPa and elasticity of up to 50% for filaments. Cell adhesion of composition investigated on fibroblast cells (hTERT BJ-5TA) is at the level of chitosan and demonstrated the absence of cytotoxicity. Full article

This study chemically characterized three Pleurotus ostreatus fruiting bodies cultivated in the Iberian Peninsula under different conditions (biological and industrial), with emphasis on polysaccharide analysis. Comprehensive comparative data on cultivation-dependent nutritional variations will potentially improve their nutritional and therapeutic applications. Industrial mushrooms (POC and POA) contained significantly higher carbohydrate content (74%), while the biologically cultivated mushroom (POL) exhibited more protein (22.6%), fat (4.2%), and ashes (8.0%). Monosaccharide analysis showed glucose dominance (28.7–45.5%), with mannose, galactose, xylose, and arabinose also present. Trehalose was the primary free sugar (4.8–14.9%). The (1→3)(1→6)-β-glucans varied significantly across samples (POL: 20.5%; POC: 29.3%; POA: 34.3%). Nuclear magnetic resonance analysis suggested complex polysaccharide arrangements. Water-soluble carbohydrates and proteins showed molecular weight distributions of 0.18–21 kDa and 0.20–75 kDa, respectively. All mushrooms were rich in essential amino acids, phosphorus (2.79–3.07%), potassium (0.56–0.68%), linoleic acid (0.82–1.14%), and oleic acid (0.22–0.31%). Fourier transform infrared confirmed a mushroom-specific biochemical profile. These findings corroborate the high nutritional value of POL, POC, and POA, with a significant contribution to the daily requirements of fiber, protein, and minerals (phosphorus, potassium, magnesium, iron, zinc, copper, and selenium), making them suitable for functional foods and nutraceuticals with cultivation-dependent nutritional profiles. Full article

Here, we demonstrated a direct method to produce cellulose nanocrystals (CNCs) with a rod-like shape from microcrystalline cellulose by a ZnCl₂-based deep eutectic solvent (DES) with a high yield (~80.1%). We obtained CNCs, crystalline index (68.9%), with a width of ~30–50 nm and a length of 200–400 nm. Importantly, we were able to functionalize the CNCs with an acetyl, -(CO)CH₃, group, which could potentially modulate the hydrophobic property of the CNCs. We attributed the formation of the CNCs to the Lewis acid effect of ZnCl₂, which can hydrolyze the amorphous cellulose regime. Our study opens a new path to directly isolate cellulose nanocrystals with several functional groups on the surface of CNCs. Full article

The synthesis of novel biodegradable polymers as non-viral vectors remains one of the challenging tasks in the field of gene delivery. In this study, the synthesis of the polysaccharide-g-polypeptide copolymers, namely, hyaluronic acid-g-polylysine (HA-g-PLys), using a copper-free strain-promoted azide-alkyne cycloaddition reaction was proposed. For this purpose, hyaluronic acid was modified with dibenzocyclooctyne moieties, and poly-L-lysine with a terminal azido group was obtained using ring-opening polymerization of N-carboxyanhydride of the corresponding protected amino acid, initiated with the amino group azido-PEG₃-amine. Two HA-g-PLys samples with different degrees of grafting were synthesized, and the structures of all modified and synthesized polymers were confirmed using ¹H NMR and FTIR spectroscopy. The HA-g-PLys samples obtained were able to form nanoparticles in aqueous media due to self-assembly driven by electrostatic interactions. The binding of DNA and model siRNA by copolymers to form polyplexes was analyzed using ethidium bromide, agarose gel electrophoresis, and SybrGreen I assays. The hydrodynamic diameter of polyplexes was ˂300 nm (polydispersity index, PDI ˂ 0.3). The release of a model fluorescently-labeled oligonucleotide in the complex biological medium was significantly higher in the case of HA-g-PLys as compared to that in the case of PLys-based polyplexes. In addition, the cytotoxicity in normal and cancer cells, as well as the ability of HA-g-PLys to facilitate intracellular delivery of anti-GFP siRNA to NIH-3T3/GFP+ cells, were evaluated. Full article

In this study, feruloylated arabinoxylans (FAXs) extracted from nixtamalized maize bran were assessed as a functional ingredient in white bread. FAXs were added at percentages of 0.15% and 0.30% to bread, and a control sample without FAXs was prepared. Regarding texture profile analysis, hardness values in bread treated with FAXs ranged from 34.32 N (T5) to 51.03 N (T3), with all values for FAXs-added bread being lower than 64.43 N obtained for the control sample (TC). With respect to color, most of the FAX-treated samples had higher overall values than the control sample, with L* values ranging from 50.49 (T4) to 59.40 (T6). The total color difference (ΔE) values ranged from 2.07 (T2) to 6.32 (T6), indicating differences between the control sample and the FAX-treated samples. In the analysis of proximate composition, all FAX-treated bread had higher levels of crude fiber content than the control sample, and water activity (aw) values were lower in the control sample than in bread treated with FAXs. Regarding total phenols, FAX-treated bread ranged from 1.57 (T6) to 1.98 (T1) mgFAE/g, being higher than the 1.24 mgFAE/g found in the control sample (TC). The antioxidant capacity levels, namely, DPPH, ABTS, and FRAP, were 9.36–17.01, 8.86–17.64, and 3.05–5.07 µmolTE/g, respectively. Thus, it is possible to conclude that adding FAXs to bread formulations improves the hardness, crude fiber content, and functional properties of bread. Full article

Microalgae-based bioremediation is increasingly recognized as a sustainable, efficient, and straightforward technology. Despite this growing interest, the potential of Parachlorella hussii for metal biosorption remains underexplored. This study is the first report evaluating the metal biosorption activity in Parachlorella hussii ACOI 1508 (N9), highlighting the impact of the culture age on the monosaccharide composition and its correlation to the metal binding capacity. The capsular strain (N9) was isolated from the hypersaline ecosystem—Lake Chott Aïn El-Beida—in southeastern Algeria. Cultivated in Bold’s Basal medium, the strain produced 0.807 ± 0.059 g L⁻¹ of RPSs and 1.975 ± 0.120 g L⁻¹ of CPSs. Biochemical analysis of the extracts revealed a high total sugar content (% w/w) that ranged from 62.98 ± 4.87% to 95.60 ± 87% and a low protein content (% w/w) that ranged from 0.49 ± 0.08% to 1.35 ± 0.69%, with RPS-D7 and RPS-D14 having high molecular weight (≥2 MDa). HPLC-based monosaccharide characterization demonstrated compositional differences between the exponential and stationary phases, with rhamnose dominating (~55%) in RPS-D14 and with the presence of uronic acids comprising 7–11.3%. Metal removal efficiency was evaluated using the whole biomass in two growth phases. Copper uptake exhibited the highest capacity, reaching 18.55 ± 0.61 mg Cu g⁻¹ DW at D14, followed by zinc removal with 6.52 ± 0.61 mg Zn g⁻¹ DW. Interestingly, removal efficiencies increased to about twofold during the stationary phase, reaching 51.15 ± 1.14% for Cu, 51.08 ± 3.35% for Zn, and 36.55 ± 3.09% for Ni. The positive results obtained for copper/zinc removal highlight the biosorption potential of P. hussii, and notably, we found that the metal removal capacity significantly improved with culture age—a parameter that has been poorly investigated in prior studies. Furthermore, we observed a growth phase-dependent modulation in monosaccharide composition, which correlated with enhanced functional properties of the excreted biomolecules involved in biosorption. This metabolic adjustment suggests an adaptive response that may contribute to the species’ effectiveness in heavy metal uptake, underscoring its novelty and biotechnological relevance. Full article

To enhance interaction with the host tissue and protect the metal surface, various surface treatments can be applied to dental implants. This study aimed to produce layer-by-layer (LbL) films by alternated immersion of the titanium sample into polyacrylic acid (PAA) and chitosan solutions, obtaining a PAA/chitosan bilayer architecture, seeking to improve the corrosion resistance. For this purpose, 03 experimental groups (n = 05) were performed: Ti-Cp (as control), Ti-Cp+8 bilayers PAA/chitosan, and Ti-Cp+12 bilayers PAA/chitosan. The corrosion behavior was assessed by using open-circuit potential (OCP), potentiodynamic polarization curves (PPcs) and electrochemical impedance spectroscopy (EIS) techniques, conducted in 0.9 wt% NaCl solution at a controlled temperature of 25 ± 1 °C. The samples were characterized morphologically and structurally by atomic force microscope (AFM), scanning electron microscopy/energy-dispersive X-ray (SEM/EDX), and X-ray diffraction (XRD) techniques before and after the corrosion tests. The electrochemical results significantly highlight the beneficial influence of coatings based on PAA/chitosan in enhancing the corrosion resistance of titanium. These findings not only corroborate the feasibility of using alternative materials for the protection of titanium but also open new possibilities for the development of innovative coatings that can be applied within the biomedical sector, serving as mediators for medicinal purposes, particularly in osteoconductive interventions. Full article

The growing demand for sustainable materials has led to innovation in the development of natural compound-based solutions for industrial applications. This study introduces composite nanoparticles (NP-CsYBE) synthesized from chitosan (Cs) and saponin-rich yucca extract (YBE), highlighting their application in Pickering emulsions (PE). Characterization via DLS and AFM revealed NP-CsYBE as spherical particles with a hydrodynamic diameter of 230 nm and a ζ-potential of +36.9 mV, showing a non-aggregated morphology. Comparative analyses of emulsions formulated with Cs nanoparticles (Cs-NP) and YBE were conducted to assess the individual contributions of each component. Functional evaluations revealed that PE based on NP-CsYBE exhibited superior stability over time compared to those with Cs-NP or YBE alone. Additionally, the rheological properties of NP-CsYBE PE were influenced by pH: liquid-viscous behavior dominated at pH 4, while at pH 6.5, solid-elastic properties prevailed. Notably, increased temperature enhanced its mechanical properties. This innovative approach provides a framework for applying natural nanoparticles in PE formation, offering potential applications in the pharmaceutical, food, medical, and cosmetic industries, as well as biomaterials for protecting lipophilic substances. By leveraging natural resources, this work advances the understanding of natural nanoparticle-based systems and their role in developing sustainable and functional materials for industrial use. Full article

Pectin–tomato paste edible films with potential antioxidant activity were studied. Initially, the films were formed by drying at 40 °C in the presence and absence of glycerol. The effect of drying temperature on several physicochemical, mechanical, and optical properties of glycerol films formed after drying at 40, 50, and 60 °C was investigated. Finally, films formed at different drying conditions (namely F40, F50, and F60) sharing the same antioxidant activity (44.28–45.53%) were studied in terms of their surface pH; solubility; folding endurance; antimicrobial, dynamic mechanical, and barrier properties; contact angle; and FT-IR. Their thickness, weight, opacity, strength, stiffness, and antioxidant activity (AA) [a*] increased with increasing tomato paste content, whereas [L*] decreased. The moisture content was statistically affected by both the presence of glycerol and the drying temperature. AA decreased as drying temperature increased. Overall, the thickness varied from 45 to 182.31 μm, weight from 0.27 to 1.24 g, moisture content from 20.74 to 56.66%, stress from 189 to 959 kPa, Young’s modulus from 86 to 382 kPa, and AA from 16.9 to 53%. In the last step, F60 was less hydrophilic, had a greater density, and better barrier properties, whereas F50 was stiffer and the least strong. Our findings provide information regarding the selection of an optimum drying temperature for pectin-based films with antioxidant properties. Full article

Heparin, a widely used polysaccharidic anticoagulant of animal origin, is associated with risks of contamination and adverse effects, notably bleeding and thrombocytopenia. These limitations have prompted interest in alternative sulfated polysaccharides with anticoagulant properties and improved safety profiles. This study explored the anticoagulant potential of two marine bacterial exopolysaccharides (EPS), infernan and diabolican. It assessed whether chemical modifications (depolymerization, oversulfation) could enhance their anticoagulant properties compared to unfractionated and low molecular weight heparins. Native EPS were depolymerized to generate different molecular weights and then chemically oversulfated to increase negative charge density. Anticoagulant activities were evaluated using clotting and thrombin generation assays (TGA). Molecular docking was performed to model interactions with antithrombin and heparin cofactor II. Only highly sulfated derivatives significantly prolonged activated partial thromboplastin time while showing negligible effect on thrombin time and anti-factor Xa activity. They present different structures, and their binding to antithrombin is not achieved via the classic pentasaccharide motif. In TGA, these derivatives inhibited thrombin formation at higher doses than heparin but induced a marked delay in clot generation. Docking analyses supported their ability to bind serpins, albeit with lower specificity than heparin. Their limited anti-Xa activity and non-animal origin position them as promising anticoagulant candidates. Full article