Search Results (164)

Microbial degumming offers an eco-friendly alternative to chemical methods for ramie fiber production, but industrial application is constrained by low efficiency stemming from limited mechanistic insight. This study systematically investigates the process using Pectobacterium carotovorum HG-49. Strain HG-49 showed a lag phase of 0–4 h, a logarithmic phase of 6–10 h, and peak biomass at 12 h. Pectin (97.05%) and water-soluble substances (98.45%) were nearly fully removed, whereas hemicellulose removal was only 73.54%, rendering it the primary residual gum component. Pectinase activity peaked at 120.75 U/mL, while mannanase (35.85 U/mL) and xylanase (30.20 U/mL) reached roughly one-quarter of that level; cellulase activity remained minimal. Scanning electron microscopy (SEM) indicated that 6–12 h constituted the main gum degradation phase. Fourier transform infrared spectroscopy (FTIR) and micro-FTIR showed progressive decreases in pectin, hemicellulose, and lignin absorption peaks with degumming. X-ray diffraction (XRD) revealed increased crystallinity from 72.07% to 80.02%, and thermogravimetric analysis (TGA) showed elevated degradation temperature from 417 °C to 435 °C. Collectively, these data confirm progressive removal of gummy substances and enhanced cellulose purity. Transcriptomic profiling further revealed that low abundance and reduced expression of hemicellulases significantly limited degumming performance. Therefore, enhancing efficiency should focus on: supplementing pectin-rich substrates to accelerate bacterial proliferation and enzyme production, broadening the hemicellulase spectrum and enhancing catalytic activities and establishing effective pretreatment protocols for ramie bast. These findings provide a theoretical foundation for improving microbial degumming efficiency and advancing industrial feasibility. Full article

Hydrocolloid-based and hydrocolloid-dominant hybrid matrices have developed from conventional rheology modifiers into functional platforms for pharmaceutical and cosmetic delivery. This review focuses on systems in which hydrocolloid chemistry, hydration, ionisation, bioadhesion, and network architecture determine swelling, mechanical behaviour, biocompatibility, and controlled release. The discussion covers alginate, chitosan, hyaluronic acid, pectin, carrageenan, dextran, gellan gum, collagen, cellulose derivatives, and selected hybrid architectures in which synthetic or semi-synthetic components provide a defined responsive function. Rather than treating all smart polymers as a single class, the review compares how pH, enzymatic, redox/ROS, thermo-responsive, magnetic, optical, ultrasound-mediated, and multi-trigger mechanisms operate within hydrocolloid-rich matrices. Pharmaceutical examples are considered across oral, transdermal, injectable depot, wound-healing, and regenerative applications, while cosmetic and cosmeceutical systems are discussed in relation to active stabilisation, dermal residence, barrier support, and personalised skincare. By linking material class, trigger mechanism, route of administration, and translational constraints, the review identifies the main advantages of hydrocolloids as delivery matrices as well as their current limitations, including burst release, modest mechanical strength, hydrophobic-drug loading challenges, sterilisation sensitivity, source variability, and regulatory complexity. Full article

Developing a Pueraria lobata compound beverage is of great significance for enhancing the utilization value of Pueraria lobata resources. However, its flavor balance, physical stability, and quality changes during storage require further investigation. This study aimed to develop a high-quality Pueraria lobata compound beverage and establish a reliable shelf-life prediction model. The optimal formulation was determined using orthogonal design and multi-index evaluation, including extract stock solution, mogroside, citric acid, and a composite stabilizer consisting of xanthan gum (XG) and sodium carboxymethyl cellulose (CMC-Na). GC-MS analysis identified multiple volatile compounds collectively forming the characteristic flavor profile. During storage, physicochemical properties, sensory quality, and active component contents changed to varying extents, with deterioration significantly accelerated at higher temperatures. Among the quality indicators, Zeta potential was selected as the most suitable predictor because it showed a strong correlation with sensory scores and fitted the first-order kinetic model well. Based on the established Arrhenius-based prediction model, the predicted shelf-lives of the Pueraria lobata compound beverage at 4 °C, 27 °C, and 37 °C were 193, 104, and 82 days, respectively. These findings provide a solid theoretical basis for formulation design, stability improvement, and shelf-life evaluation of functional Pueraria lobata beverages. Full article

Hydrocolloids comprise a diverse class of high-molecular-weight polymeric carbohydrates associated with a wide range of physicochemical and functional properties. This review provides an integrated analysis of natural hydrocolloids derived from algal (agar, alginate, carrageenan, fucoidan, laminarin, and ulvan), animal (chitin, chitosan, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, glycogen, and hyaluronan), and plant (pectin, starch, and locust bean gum) sources, together with semisynthetic cellulose-based derivatives. Emphasis is placed on the relationship between molecular structure, charge density, sulfation patter, and branching degree, and how these parameters modulate hydration, gelation, and rheological behavior. Comparative analyses are presented, establishing structure–function interactions that link molecular characteristics to functional properties, including thickening, gelling, emulsifying, stabilizing, film-forming, and controlled-release capacities. The review also discusses the biological activities and application potential of these hydrocolloids in pharmaceutical, biomedical, and advanced material systems. In addition, emerging modification strategies, including chemical functionalization, crosslinking, and nanostructuring are discussed as tools to adjust their action and diversify their application range. Special attention is given to structure–rheology–gelation relationships and to the influence of molecular organization on mechanical strength, stability, and delivery performance. Current challenges associated with scalability, processability, reproducibility, and long-term functional stability are also critically discussed. Overall, this review provides a comprehensive structure–function perspective on hydrocolloids as sustainable and multifunctional polymeric materials, supporting their rational design and continued development in pharmaceutical sciences, biomedical engineering, and advanced material applications. Full article

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

Acidified milk drinks (AMDs) are susceptible to protein aggregation and phase separation during production and storage, and xanthan gum (XG) is limited in application due to poor compatibility with milk proteins under acidic conditions. This study sought to improve the stabilizing performance of XG in AMDs through TEMPO-mediated oxidation. A series of oxidized xanthan gum (OXG) with different oxidation degrees were prepared by the TEMPO/NaClO/NaBr system, whose physicochemical properties were characterized, and the stabilizing effect and mechanism in AMDs were investigated. The results showed that high-degree OXG significantly improved the stability of AMDs, with the centrifugal sedimentation rate reduced from 8.93% to 2.22% and the zeta potential decreased from −32.6 mV to −37.9 mV, achieving a stabilizing effect comparable to that of sodium carboxymethyl cellulose (CMC). OXG could form uniform protein–polysaccharide aggregates with milk proteins, which may help inhibit phase separation. This study confirms that TEMPO oxidation can directionally regulate the structure and physicochemical properties of XG, enhancing its stabilizing effect in AMDs, which provides a new technical approach and theoretical basis for polysaccharide modification and the stabilization of acidic protein drinks. Full article

Wearable electrodes have attracted attention for their ability to monitor human electrophysiological signals, such as those generated by the heart and captured via electrocardiography (ECG). In this study, an easy and scalable drop-coating method was used to develop flexible, dry, and sustainable ECG electrodes composed of a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/polyvinyl alcohol/xanthan gum (PXP) composite. The electrodes were fabricated on different cellulosic substrates, such as Xuan paper, Kraft paper, and wheat bagasse, and further modified through the incorporation of MoO₃ (PXPM composite). PXP exhibits a broad absorption band of 350–550 nm, while PXPM shows a shifted band of 400–750 nm, due to the interaction of MoO₃ with PEDOT:PSS. The fluorescence emission of PXP appears at 443 nm, while the emission for PXPM is broader and centered at 437 nm. Electrically, both composites exhibit continuity and ohmic behavior. Microstructural analysis revealed that the interaction between the composite film and the substrate strongly influences pore formation, film uniformity, and the distribution of Mo species, highlighting the role of MoO₃ as an interfacial modifier that promotes smoother and more homogeneous coatings on selected cellulosic substrates. All fabricated electrodes demonstrated the capability to detect ECG signals with sufficient quality to be clinically valid. Full article

The structure collapse and performance degradation caused by traditional air-drying technology often hinder the practical application of bio-based xerogels as absorbent pads. In this study, chitosan (CS) and different types of polyanions (carboxymethyl cellulose (CMC), sodium alginate (SA), hyaluronic acid (HA), pectin (PT) and xanthan gum (XG)) in different proportions were used to prepare an xerogel resistant to atmospheric pressure air drying collapse, and its potential as an absorption pad was systematically evaluated. The results showed that among all the treatments, CS/CMC xerogel at an optimal mass ratio of 1:3 demonstrated superior comprehensive properties. It exhibited minimal shrinkage (p < 0.05) and high porosity, coupled with an exceptional water absorption capacity (140% higher than CS/PT) and hardness (96% higher than CS/SA and CS/HA). FTIR and XRD revealed that strong electrostatic interactions and potential amide bond formation between CS and CMC resulted in a dense yet homogeneous network with low crystallinity. SEM imaging further corroborated a uniform thin-walled porous structure. This stable network contributed to high toughness, of CS/CMC significantly surpassing the brittle CS/XG and CS/PT xerogels (p < 0.05). CS/CMC xerogel is an ideal absorbent material with high absorption, stability, and controllable structure. Full article

Biopolymers are increasingly explored as safer and more sustainable food packaging materials. This study evaluated the migration behavior of intentionally and non-intentionally added substances (IAS and NIAS), as well as the safety of gelatin and xanthan gum blends reinforced with microcrystalline cellulose, with and without oxygen plasma treatment, incorporating glycerol and limonene as plasticizers. Migration tests were conducted according to European Union (EU) Regulation No. 10/2011 using simulants of different polarities, and IAS/NIAS were analyzed by gas chromatography–mass spectrometry and ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometry (GC–MS and UPLC-QTOF-MS). Films containing limonene were also evaluated for antioxidant activity. Results showed that plasticizer migration is strongly influenced by simulant polarity, glycerol predominantly migrated into hydrophilic media, whereas limonene and its derivatives exhibited higher migration in fatty simulants. Ethanol 95% acted as a conservative worst-case simulant, promoting extensive migration, while substantially lower migration levels were observed in isooctane and tenax plasma treatment resulted in modest changes in volatile compound migration, while significantly enhancing the antioxidant activity of limonene-containing films. Although overall migration levels were low under most of the tested conditions, NIAS formation, particularly from limonene degradation, highlights the need to account for chemical stability and simulant type when assessing bio-based films. Overall, the study demonstrates that film composition, surface modification, and simulant characteristics jointly influence migration behavior and functional performance under the evaluated conditions reinforcing the need to adapt current regulatory frameworks to the specific behavior of biopolymeric packaging materials. Full article

Polysaccharides extracted from Japanese pumpkin (Cucurbita maxima Duchesne) possess antioxidant activity and moisturizing effects. To meet the demand for natural skincare, this study aims to develop ultra-micro liquid crystal (ULC) emulsions containing pumpkin seed oil (PO) and Japanese pumpkin polysaccharide (PP). The novelty lies in the synergistic triple-action mechanism of the lipid lamellar structure, emollients and humectants, which together achieve superior moisturization. The formulation is varied by different emulsifiers (Emulgade^® PL 68/50 and Olivem^® 1000), thickening agents (0.3–0.5% w/w of hydroxyethyl cellulose, xanthan gum, or guar gum), and active concentrations of 2.0–4.0% w/w PO and 0.1% w/w PP. Physicochemical characterization was conducted via polarized light microscopy, particle size analysis, and wide-angle X-ray diffraction (WAXD). Stability was assessed through centrifugation and six heating–cooling cycles, while clinical safety and moisturizing efficacy were evaluated in human volunteers using the Corneometer^® and Tewameter^®. Polarized light microscopy revealed distinct Maltese cross structures, while WAXD confirmed the presence of α-gel and lamellar (Lα) phases. The ULC emulsion containing PO and PP (F9), comprising 4.5% Emulgade^® PL 68/50, 0.3% xanthan gum, 2.0% PO, and 0.1% PP, demonstrated excellent physical stability and a particle size of 4.02 ± 0.02 µm. Clinical results demonstrated that F9 was non-irritating and significantly enhanced skin hydration, while reducing transepidermal water loss compared to the baseline (p < 0.05). Although F9 showed the greatest numerical improvement in barrier function, its efficacy was comparable to placebo cream and ULC emulsion containing PO (F6) (p > 0.05). In conclusion, the successful integration of pumpkin-derived actives into a stable ULC system provides a safe and effective approach for advanced moisturizing skincare applications. Full article

Wound-related inflammatory pain is a major contributor to wound healing success and requires wound-specific therapeutic platforms with minimal systemic adverse effects. This study builds a dual-crosslinked polyvinyl alcohol (PVOH)/carboxymethyl cellulose (CMC)/gellan gum hydrogel system with optimized mechanical strength and sustained anti-inflammatory drug delivery by developing predictive mathematical models using response surface methodology with central composite design. The effects of citric acid (5–15% w/w) and dialdehyde carboxymethyl cellulose (DCMC, 0.0125–0.0375% w/w) on mechanical properties were systematically evaluated. The optimal formulation (2.23 g low-acyl gellan gum, 1.00 g high-acyl gellan gum, 0.02% DCMC, 10.21% citric acid) achieved firmness of 1.27 ± 0.06 N, rupture strength of 24.24 ± 0.52 N, and compressive strength of 41.91 ± 0.62 kPa. Curcumin oil incorporation yielded 82% cumulative release over 360 min following Korsmeyer–Peppas kinetics (R² = 0.9887, n = 0.8773). Cell viability exceeded 70% throughout the release period, confirming biocompatibility. The hydrogel strongly inhibited reactive oxygen species (ROS) and nitric oxide (NO) production in lipopolysaccharide-stimulated macrophages (p < 0.001) and enhanced macrophage migration, increasing wound closure from 40–80% (p < 0.001). This dual-crosslinked hydrogel shows great potential for localized inflammatory pain relief. Full article

Meat products are prone to spoilage during storage and transportation due to the decomposition of amino acids and proteins, which generates volatile amines and elevates pH levels. In recent years, research on pH indicator labels for food has significantly increased. This study investigates a functional film with a bilayer structure for real-time freshness monitoring of meat. Utilizing Tara gum (TG) and Gellan gum (GG) as the base material and nanocellulose composite GG/blueberry anthocyanins as the sensing layer, titanium dioxide was incorporated to effectively block ultraviolet radiation. Through response surface methodology, the cellulose nanocrystals (CNCs) preparation process was optimized to address issues such as insufficient mechanical properties, hydrophobicity, and thermal stability of the composite film. Results showed that the composite film achieved optimal performance when CNC content was 6%. This research provides a simple and effective solution for real-time freshness monitoring of meat products, offering advantages such as low cost, environmental friendliness, and user-friendly operation. Full article

Climate change and the impacts related to nonbiodegradable synthetic materials highlight the need for sustainable alternatives. Biopolymers from renewable sources show great potential for producing hydrogels, which are three-dimensionally crosslinked materials with high water absorption. In this work, super-absorbent biodegradable hydrogels were produced via single-step reactive extrusion using mixtures of starch, gelatin, cellulose, and xanthan gum, with glycerol as a plasticizer, and citric acid as a crosslinking agent. Pelleted hydrogels were obtained with water absorption between 290% and 363%. Reactive extrusion promoted the formation of new ester and amide bonds, confirmed by FT-IR. Citric acid was effective as a crosslinker, and higher citric acid content (3%) produced samples with greater swelling, supported by the porous internal structure observed. Preliminary agricultural tests showed that the formulation with the highest citric acid content, when added to soil at 5%, significantly increased water-holding capacity and resulted in the highest germination rate of maize seeds. Overall, the extrusion process proved efficient, scalable, and environmentally friendly for producing biodegradable hydrogels for agricultural applications. Full article

The design of sustainable hydrogel materials with tunable mechanical and thermal properties is essential for emerging applications in flexible and wearable electronics. In this study, hydrogels based on natural gums such as Guar, Tara, and Xanthan and their composites with Cellulose Citrate were developed through a mild physical crosslinking process, ensuring environmental compatibility and structural integrity. The effect of cellulose citrate pretreatment under different alkaline conditions (0.04%, 5%, and 10% NaOH) was systematically investigated using Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and dynamic rheology. Overall, the results show that the composites exhibit different properties of the hydrogel networks compared to the pure hydrogel gums, strongly depending on the alkaline treatment. In all composite hydrogels, a significant increase in the number of interacting rheological units occurs, though the strength of the interactions decreases in Guar and Tara composites, which exhibit partial structural destabilization. In contrast, Xanthan–Cellulose Citrate hydrogels display enhanced strong gel character, and crosslinking density. These improvements reflect stronger intermolecular associations and a more compact polymer network, due to the favorable H-bonding and ionic interactions among Xanthan, Cellulose and Citrate mediated by water and sodium ions. Overall, the results demonstrate that Xanthan–Cellulose Citrate systems represent a new class of eco-friendly, mechanically robust hydrogels with controllable viscoelastic and thermal responses, features highly relevant for the next generation of flexible, self-supporting, and responsive soft materials suitable for wearable and stretchable electronic devices. Full article

In this study, we prepared guar gum (GG) films using a compression molding technique for the first time, incorporating glycerol as a plasticizer and microcrystalline cellulose (MCC) as a reinforcing filler. The chemical structures, thermal properties, crystalline structures, phase morphology, mechanical properties, moisture content, and film opacity of thermo-compressed GG films were investigated. The results show that using glycerol as a plasticizer enhanced the flexibility of the thermo-compressed GG film and promoted its crystallization. The incorporation of glycerol enhanced the thermal stability of the GG film matrix. The addition of MCC enhanced the tensile strength of the plasticized GG film; however, it resulted in a decrease in elongation at break. The incorporation of MCC in plasticized GG films resulted in enhanced opacity and a decrease in moisture content. Thermo-compressed GG films can be customized to exhibit various properties by adjusting the glycerol and MCC contents, making them suitable for a range of eco-friendly and sustainable packaging applications. Full article