Search Results (358)

The development of active food packaging has evolved rapidly in recent years, offering innovative solutions to enhance food preservation and safety while addressing sustainability challenges. This review compiles and analyzes recent advancements (2019–2024) in release-type active packaging, focusing on essential oils, natural extracts, and phenolic compounds as active agents. Primarily plant-derived, these compounds exhibit significant antioxidant and antimicrobial activities, extending shelf life and enhancing food quality. Technological strategies such as encapsulation and polymer blending have been increasingly adopted to overcome challenges related to volatility, solubility, and sensory impact. Integrating bio-based polymers, including chitosan, starch, and polylactic acid, further supports the development of environmentally friendly packaging systems. This review also highlights trends in compound-specific research, release mechanisms, and commercial applications, including a detailed analysis of patents and case studies across various food matrices. These developments have already been translated into practical applications, such as antimicrobial sachets for meat and essential oil-based pads for fresh produce. Moreover, by promoting the valorization of agro-industrial by-products and the use of biodegradable materials, emission-type active packaging contributes to the principles of the circular economy. This comprehensive overview underscores the potential of natural bioactive compounds in advancing sustainable and functional food packaging technologies. Full article

The demand for anion exchange membranes (AEMs) is growing due to their applications in water electrolysis, CO₂ reduction conversion and fuel cells, as well as water treatment, driven by the increasing energy demand and the need for a sustainable future. However, current AEMs still face challenges, such as insufficient permeability and stability in strongly acidic or alkaline media, which limit their durability and the sustainability of membrane fabrication. In this study, polyvinyl alcohol (PVA) and chitosan (CS) biopolymers are selected for membrane preparation. Zinc oxide (ZnO) and porous organic polymer (POP) nanoparticles are also introduced within the PVA-CS polymer blends to make mixed-matrix membranes (MMMs) with increased OH⁻ transport sites. The membranes are characterized based on typical properties for AEM applications, such as thickness, water uptake, KOH uptake, Cl⁻ and OH⁻ permeability and ion exchange capacity (IEC). The OH⁻ transport of the PVA-CS blend is increased by at least 94.2% compared with commercial membranes. The incorporation of non-porous ZnO and porous POP nanoparticles into the polymer blend does not compromise the OH⁻ transport properties. On the contrary, ZnO nanoparticles enhance the membrane’s water retention capacity, provide basic surface sites that facilitate hydroxide ion conduction and reinforce the mechanical and thermal stability. In parallel, POPs introduce a highly porous architecture that increases the internal surface area and promotes the formation of continuous hydrated pathways, essential to efficient OH⁻ mobility. Furthermore, the presence of POPs also contributes to reinforcing the mechanical integrity of the membrane. Thus, PVA-CS bio-based membranes are a promising alternative to conventional ion exchange membranes for various applications. Full article

Honey, propolis or royal jelly are considered natural remedies with therapeutic properties since antiquity. Many papers explore the development of antimicrobial biomaterials based on individual bee products, but there is a lack of studies on their synergistic effects. Combining honey, propolis and royal jelly with silver nanoparticles in a biopolymer matrix offers a synergistic strategy to combat antibiotic-resistant bacterial infections. This approach supports progress in wound healing, soft tissue engineering and other domains where elimination of the microorganisms is needed like food packaging. In this study we have obtained antimicrobial films based on bee products and silver nanoparticles (AgNPs) incorporated in an alginate–chitosan blend. The novel biomaterials were analyzed by UV-Vis, fluorescence and FTIR spectroscopy or microscopy, SEM and thermal analysis. Antibacterial tests were conducted against both Gram-positive and Gram-negative bacteria, while the antifungal properties were tested against Candida albicans. The diameters for growth inhibition zones were up to 10 mm for bacterial strains and 8 mm for the fungal strain. Additionally, cytotoxicity assays were performed to evaluate the biocompatibility of the materials, the results indicating that the combination of honey, propolis, royal jelly and AgNPs does not produce synergistic toxicity. Full article

Despite its broad application due to its affordability, biodegradability, and natural antimicrobial and antioxidant activities, chitosan (CS) still exhibits limitations in mechanical strength and barrier effectiveness. Owing to its unique chemical characteristics, itaconic acid (IT) presents potential as a compatibilizing agent in polymeric blend formulations. Biodegradable polymers composed of chitosan (CS), itaconic acid (IT), and starch (S) were synthesized using two polymerization methods. The first method involved grafting IT onto CS at varying ratios of IT (4%, 6%, and 8% wt.), using 1% v/v acetic acid/water as the solvent and potassium persulfate as the initiator. In the second approach, starch (S) was blended with the copolymer P(CS-g-IT) at concentrations of 1%, 3%, and 5%, utilizing water as the solvent and glacial acetic acid as a catalyst. The resulting biodegradable films underwent characterization through FTIR, TGA, SEM, and mechanical property analysis. To further explore the effects of combining IT, starch, and carbon black, the blends, referred to as P[(CS-g-IT)-b-S], were also loaded with carbon black. This allowed for the evaluation of the materials’ physicomechanical properties, such as viscosity, tensile strength, elongation, and contact angle. The findings demonstrated that the presence of IT, starch, and carbon black collectively improved the films’ mechanical performance, physical traits, and biodegradability. Among the samples, the blended copolymer with 1% starch exhibited the highest mechanical properties, followed by the grafted copolymer with 8% IT and the blended copolymer mixed with carbon black at 7%. In contrast, the blended copolymer with 5% starch showed the highest hydrophilicity and the shortest degradation time compared to the grafted copolymer with 8% IT and the blended copolymer mixed with 7% carbon black. Full article

With the increasing demand for food quality and the need for green and sustainable development of food packaging materials in the environment, the preparation and optimization of multifunctional natural and renewable antibacterial packaging materials have become an important trend. This article aims to explore the development of chitosan–cellulose composite materials with good antibacterial properties and promote the widespread application of chitosan and cellulose in food packaging materials. Combining various natural polysaccharide polymers, we discuss the application of chitosan cellulose in meat, dairy products, fruits and vegetables, and fishery products. Meanwhile, we explore their antibacterial and antioxidant behaviors during their use as food packaging materials. This provides a reference for effectively improving the performance of modified chitosan and cellulose food packaging materials in the future. Based on the above explanation, we analyzed the advantages and disadvantages of modified chitosan and cellulose and looked forward to the future development trends of chitosan and cellulose blend films in food preservation. Chitosan–cellulose blends not only have important prospects in food packaging and preservation applications, but can also be combined with intelligent manufacturing to enhance their food preservation performance. The aim of this review is to provide valuable references for basic research on the antimicrobial properties of these composites and their practical application in smart food packaging. Full article

In recent years, coffee waste by-products have been incorporated into polymer blends to reduce environmental pollution. In this study, coffee parchment (CP) was incorporated into biodegradable polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) polymer blends to prepare ribbons through the extrusion process. Extracted green coffee bean oil (CO) was used as a plasticizer, and CP was used as a filler with and without functionalization. A solution of chitosan nanoparticles (ChNp) as a coating was applied to the ribbons. For the raw material, proximal analysis of the CP showed cellulose and lignin contents of 53.09 ± 3.42% and 23.60 ± 1.74%, respectively. The morphology of the blends was observed via scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) showed an increase in the ribbons’ thermal stability with the functionalization. The results of differential scanning calorimetry (DSC) revealed better miscibility for the functionalized samples. The mechanical properties showed that with CP incorporation into the blends and with the ChNp coating, the Young’s modulus and the tensile strength decreased with no significant changes in the elongation at break. This work highlights the potential of reusing different by-products from the coffee industry, such as coffee oil from green beans and coffee parchment as a filler, and incorporating them into PLA PBAT biodegradable polymer blend ribbons with a nanostructured antimicrobial coating based on chitosan for future applications in food packaging. Full article

Current hydrogels used for cartilage tissue engineering often lack the mechanical strength and structural integrity required to mimic native human cartilage. This study addresses this limitation by developing reinforced hydrogels based on a ternary polymer blend of poly(vinyl) alcohol (PVA), gelatin (GL), and chitosan (CH), with gentamicin sulfate (GS) as an antimicrobial agent and a crosslinker. The hydrogels were produced using two crosslinking methods, the freeze/thaw and heated cycles, and reinforced with forcespun polycaprolactone (PCL) nanofiber to improve mechanical performance. Chemical characterization revealed that GS forms weak hydrogen bonds with the ternary polymers, leading to esterification with PVA, and covalent bonds are formed as the result of the free amino group (-NH₂) of chitosan that reacts with the carboxylic acid group (-COOH) of gelatin. SEM images help us to see how the hydrogels are reinforced with polycaprolactone (PCL) fibers produced via force spinning technology, while mechanical properties were evaluated via uniaxial tensile and compressive tests. Water retention measurements were performed to examine the crosslinking process’s influence on the hydrogel’s water retention, while the hydrogel surface roughness was obtained via confocal microscopy images. A constitutive model based on non-Gaussian strain energy density was introduced to predict experimental mechanical behavior data of the hydrogel, considering a non-monotonous softening function. Loading and unloading tests demonstrated that GS enhanced crosslinking without compromising water retention or biocompatibility because of the reaction between the free amino group of CH and the carboxylic group of gelatin. The PCL-reinforced PVA/GL/CH hydrogel shows strong potential for cartilage repair and tissue engineering applications. Full article

Polyphenols exert anti-inflammatory and antioxidant effects by modulating cell signalling pathways and transcription factors involved in inflammatory bowel disease (IBD). However, their stability during digestion can be compromised. Polymer coatings like chitosan (-C) help preserve their stability. Maqui (Aristotelia chilensis) and murta (Ugni molinae) are rich in antioxidant and anti-inflammatory compounds. This work aims to obtain extracts (E) and blends (B) enriched in delphinidin and quercetin glucosides from maqui (Ma) and murta (Mu) crude extracts using preparative chromatography methodology (Prep-HPLC) and to evaluate their effectiveness through in vitro and cellular assays. HPLC-DAD analysis revealed a marked increase in phenolic compound concentration in the BEMaMu and BCMaMu extract blends. Total quercetin glycosides (TQG) increased by 11-fold, and total anthocyanins increased by approximately 8-fold compared to the fruit blend (BMaMu). BCMaMu exhibited a significantly higher ORAC value compared to the estimated additive mixture, suggesting a synergistic effect. No cytotoxicity was observed for BEMaMu, BCMaMu, and their chitosan-coated versions (BEMaMu-C and BCMaMu-C) in Caco-2 and HT29-MTX-E12 cells at concentrations of 0.1–50 mg/mL. Notably, only chitosan-coated BCMaMu inhibited NF-κB expression and activated Nrf2 in TNF-α-challenged Caco-2 cells at 0.1 and 0.5 mg/mL. Full article

One of the most pressing issues confronting modern society is carbon dioxide pollution (CO₂). The reliance of social progress on CO₂-producing technologies such as power generation, automobiles, and specialized industrial processes exacerbates the problem. Due to this reliance, it is critical to develop solutions to reduce CO₂ emissions from these sources. One such solution is carbon capture and sequestration (CCS), which employs chemical methods to prevent CO₂ emissions. The irreversibility of current CCS technology is its primary problem. Chitin, chitosan, and their derivatives, which were recovered from local seafood waste, are studied as reversible CO₂ capture materials in this study in an effort to lessen this issue. Polysulfone (PSF) blends were employed to lessen chitosan edema, as chitosan’s hydrophilicity reduces its active sorption surface. Blends with only 20% chitosan have the same high sorption capacity as pure chitosan due to decreased swelling. Hydrolysis was used to boost the chitin sorption abilities. The CO₂ sorption data were analyzed using an Intelligent Gravimetric Analyzer (IGA), Fourier-Transform Infrared (FTIR) spectroscopy, and Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) spectroscopy. This study reveals that shrimp shells were the best source of chitin. This research led to the creation of eco-friendly, reversible, and reusable carbon sequestration sorbents. Full article

Carbohydrate-based biodegradable films offer an eco-friendly alternative to conventional petroleum-derived packaging for agricultural commodities. Derived from renewable polysaccharides such as starch, cellulose, chitosan, pectin, alginate, pullulan, and xanthan gum, these films exhibit favorable biodegradability, film-forming ability, and compatibility with food systems. This review presents a comprehensive analysis of recent developments in the preparation, functionalization, and application of these polysaccharide-based films for agricultural packaging. Emphasis is placed on emerging fabrication techniques, including electrospinning, extrusion, and layer-by-layer assembly, which have significantly enhanced the mechanical, barrier, and antimicrobial properties of these materials. Furthermore, the incorporation of active compounds such as antioxidants and antimicrobials has improved the performance and shelf-life of packaged goods. Despite notable advancements, key limitations such as moisture sensitivity, poor mechanical durability, and high production costs persist. Strategies including polymer blending, nanofiller incorporation, and surface modification are explored as potential solutions. The applicability of these films in packaging fruits, vegetables, dairy, grains, and meat products is also discussed. By assessing current progress and future prospects, this review underscores the importance of carbohydrate-based films in promoting sustainable agricultural packaging systems, reducing environmental impact through the advancement of circular bioeconomy principles and sustainable development. Full article

The integration of biopolymers with antimicrobial inorganic materials has emerged as a promising strategy for developing eco-friendly and biocompatible functional materials for food packaging and biomedical applications. However, the impact of biopolymer matrix composition on the antimicrobial efficacy of inorganic fillers remains underexplored. This study addresses this critical gap by investigating the effects of chitin or chitosan oligosaccharides (NACOS or COS) on the antimicrobial properties of sodium alginate (SA)/cuprous oxide (Cu₂O) composite gels. The composite gels were synthesized through a physical blending of the components, followed by calcium-induced crosslinking of SA. Characterization using UV-vis, FTIR, and EDX confirmed the successful incorporation of Cu₂O, while a SEM analysis revealed its uniform dispersion. Antibacterial assays demonstrated that SA-Cu₂O exhibited the highest inhibition rates, with a 67.4 ± 11.9% growth suppression of Staphylococcus aureus (MRSA), 33.7 ± 5.1% against Escherichia coli, and 39.1 ± 14.8% against Pseudomonas aeruginosa. However, incorporating NACOS and COS reduced inhibition, as oligosaccharides served as bacterial carbon sources. Swelling and contact angle measurements indicate that antimicrobial effectiveness was independent of surface hydrophilicity. These findings underscore the importance of rational composite design to balance bioactivity and material stability for antimicrobial applications. Full article

The highly efficient removal of mercury metal ions at a higher pH (basic media) is barely reported in the literature. In this study, we developed a novel adsorbent by blending chitosan with guar gum, designed to effectively remove mercury ions from basic media by stabilizing them with a gold (Au³⁺) solution. The FTIR confirmed the compatibility of chitosan and guar gum through hydrogen bonding. The morphology of the blend exhibited an amorphous and porous structure. A mesoporous structure with a surface area, volume, and diameter of 11.843 (m²/g), 0.184 (cm²/g), and 17.072 nm, respectively, was confirmed by BET. The adsorption behavior was analyzed using isotherms and kinetics models, which best fitted with the pseudo-second-order kinetic model and Freundlich adsorption isotherm model, respectively. The adsorbent was shown to be an excellent candidate for the removal of mercury ions in water, with an adsorption efficiency of 92% at pH 12 in 60 min and a maximum adsorption capacity of 370.37 (mg/g). Full article

New sustainable materials have been developed to replace conventional plastics obtained from non-renewable sources. In this study, cellulose fibres from Posidonia oceanica (PO) were obtained by applying subcritical water extraction and bleaching with hydrogen peroxide or sodium chlorite. The PO fibres were used to obtain cellulose films, chitosan–cellulose composites, and PLA–cellulose laminates. These films were characterised as to their optical properties, mechanical performance, oxygen and water vapour permeability, thermal stability, and microstructure. The cellulose films exhibited low mechanical resistance, with different colouration depending on the degree of delignification. The composites had lower mechanical strength than pure chitosan films. The PO cellulose fibres had a similar, but attenuated, effect when laminated with PLA layers. The fibres improved the oxygen barrier capacity of chitosan films, although this effect only occurred in PLA laminates for cellulose purified with sodium chlorite. In no case did cellulose improve the water vapour barrier of the films compared to pure polymers. The thermal stability was not notably altered by the blending effect, thus reflecting the absence of significant interactions between the fibres and polymer. However, there is a need to improve the functionality of cellulose fibres from PO waste for their incorporation as fillers or laminates in biodegradable food packaging materials. Full article

Growing concerns over the environmental impact of plastic packaging have driven interest in sustainable alternatives, particularly biopolymer-based films. This study developed ternary-blended polysaccharide gel films composed of carboxymethyl starch (CMS), chitosan (CS), and pectin (PT), with dialdehyde carboxymethyl cellulose (DCMC) as a crosslinker, and investigated the effects of honey bee brood protein (BBP) (0–0.4% w/v) on their mechanical, barrier, and thermal properties. A completely randomized design (CRD) was employed to evaluate the impact of BBP concentration on film characteristics. Results demonstrated that adding 0.4% BBP enhanced water vapor barrier properties and thermal stability while reducing hydrophilicity. The optimal formulation was observed at 0.1% BBP, providing the highest tensile strength (7.73 MPa), elongation at break (32.23%), and water-absorption capacity (369.01%). The improvements in thermal stability and hydrophilicity were attributed to BBP’s hydrophobic amino acids, which interacted with DCMC to form a denser polymer network, enhancing structural integrity and moisture resistance. Additionally, BBP incorporation contributed to the biodegradability of polysaccharide gel films, improving their environmental sustainability compared to conventional biopolymers. The findings suggest that BBP can serve as a functional additive in polysaccharide-based films, balancing performance and eco-friendliness for applications in biodegradable food and medical packaging. Full article

Hydrogels are promising materials for biomedical applications due to their tunable properties. Despite significant research on optimizing the mechanical and rheological properties of chitosan hydrogels, a comprehensive analysis incorporating pH and molarity of the neutralizing solution is still lacking. This study addresses this gap by evaluating how these factors influence the rheological characteristics of chitosan hydrogels. The hydrogels were prepared using an acidic blend and were neutralized with sodium hydroxide solutions. Rheological characterization demonstrated that all samples exhibited pseudoplastic behavior, with viscosity decreasing under shear stress. Hydrogels with higher pH values exhibited lower viscosity, which is attributed to the reduced protonation and weaker electrostatic repulsion between chitosan chains. In contrast, more acidic conditions resulted in increased viscosity and greater chain entanglements. NaOH concentration impacted gel stability; lower concentrations resulted in more stable gels, whereas higher concentrations increased crosslinking but compromised integrity at elevated pH. These findings provide essential insights for optimizing chitosan hydrogels with customized properties, making them highly suitable for specific biomedical applications, such as advanced 3D-printed wound dressings. Full article