Ethyl cellulose matrixed poly(sulfur-co-sorbic acid) composite films: Regulation of properties and application for food preservation.

Developing non-toxic and sustainable materials with versatile and diverse functions has always been a crucial issue in food preservation packaging. Recently, inverse vulcanization has emerged as a precise and eco-friendly solution, attributed to the versatility of resulting polysulfides. In this study, a polysulfide crosslinked with sorbic acid was prepared by inverse vulcanization, and further combined with bio-macromolecular ethyl cellulose to form composite films via a casting method. Thanks to the ethanol-solubility and good compatibility of ethyl cellulose towards the polysulfide, morphology of the films can be tailored by adjusting the component ratio, thereby achieving favorable water vapor permeability (2.20 × 10-12 gs-1m-1Pa-1), oxygen permeability (4.01 × 10-4 gs-1 m-2), elasticity modulus (~400 MPa), elongation at break (~16 %), etc. Some films demonstrate remarkable antibacterial activity against a broad spectrum of bacteria and fungi, demonstrating their effectiveness in food preservation. The browning and spoilage of preserved Agaricus bisporus were inhibited, with 79.2 % of the initial firmness retained and a 5.6 % weight loss recorded on the 6th day. For the 15-day preservation of grapes, minimal changes in appearance, firmness, or TSS were observed, underscoring the promising potential of this composite for food preservation applications.

Stability of Dexamethasone during Hot-Melt Extrusion of Filaments based on Eudragit® RS, Ethyl Cellulose and Polyethylene Oxide.

Hot-melt extrusion (HME) potentially coupled with 3D printing is a promising technique for the manufacturing of dosage forms such as drug-eluting implants which might even be individually adapted to patient-specific anatomy. However, these manufacturing methods involve the risk of thermal degradation of incorporated drugs during processing. In this work, the stability of the anti-inflammatory drug dexamethasone (DEX) was studied during HME using the polymers Eudragit® RS, ethyl cellulose and polyethylene oxide. The extrusion process was performed at different temperatures. Furthermore, the influence of accelerated screw speed, the addition of the plasticizers triethyl citrate and polyethylene glycol 6000 or the addition of the antioxidants butylated hydroxytoluene and tocopherol in two concentrations were studied. The DEX recovery was analyzed by a high performance liquid chromatography method suitable for the detection of thermal degradation products. The strongest impact on the drug stability was found for the processing temperature, which was found to reduce the DEX recovery to <20% for certain processing conditions. In addition, differences between tested polymers were observed, whereas the use of additives did not result in remarkable changes in drug stability. In conclusion, suitable extrusion parameters were identified for the processing of DEX with high drug recovery rates for the tested polymers. Moreover, the importance of a suitable analysis method for drug stability during HME that is influenced by several parameters was highlighted.

Inside-out templating: A strategy to decorate helical carbon nanotubes and 2D MoS2 on ethyl cellulose sponge for enhanced oil adsorption and oil/water separation.

Ethyl cellulose (EC)-based composite sponges were developed for oil spillage treatment. The EC sponge surface was decorated with helical carbon nanotubes (HCNTs) and molybdenum disulfide (MoS2) (1 phr) using the inside-out sugar templating method. The inside surface of a sugar cube was coated with HCNTs and MoS2. After filling the sugar cube pores with EC and the subsequent sugar leaching, the decorating materials presented on the sponge surface. The EC/HCNT/MoS2 sponge had a high level of oil removal based on its adsorption capacity (41.68 g/g), cycled adsorption (∼75-79 %), separation flux efficiency (∼85-95 %), and efficiency in oil/water emulsion separation (92-94 %). The sponge maintained adsorption capacity in acidic, basic, and salty conditions, adsorbed oil under water, and functioned as an oil/water separator in a continuous pump-assisted system. The compressive stress and Young's modulus of the EC sponge increased following its decoration using HCNTs and MoS2. The composite sponge was robust based on cycled compression and was thermally stable up to ∼120 οC. Based on the eco-friendliness of EC, the low loading of HCNTs and MoS2, and sponge versatility, the developed EC/HCNT/MoS2 sponge should be good candidate for use in sustainable oil adsorption and separation applications.

Fluffy-like amphiphilic graphene oxide and its effects on improving the antibacterial activity and thermal outstanding of ethyl cellulose /polyvinyl alcohol hydrogel film.

The antibacterial characteristics of graphene oxide (GO-SB) nano-sheets generated by charring sugarcane bagasse (SB) are described in this study. The antibacterial capability of GO-SB was improved when it was grafted with ethyl cellulose (EC) and polyvinyl alcohol (PVA) to form GO-SB/EC/PVA hydrogels. Characterization of GO-SB nanosheets and GO-SB/EC/PVA hydrogels was accomplished by using FTIR, SEM, XRD, and thermal studies. The antimicrobial activity was carried out against Gram positive bacteria [Micrococcus leutus & Staphylococcus aureus], Gram negative bacteria [Escherichia coli, Pseudomonas aeruginosa] and pathogenic fungal yeast [Candida albicans] applying the disc diffusion method. The disc diffusion method results showed that the improved GO-SB/EC/PVA exhibited a reasonable level of antimicrobial capability against Micrococcus leutus, demonstrating that the antimicrobial improvement of GO-SB was more effective in the GO-SB/EC/PVA hydrogels by increasing the inhibition zone of Gram-positive bacteria, Micrococcus leutus from (13.0 to 16.0 mm).

Hybrid Ethylcellulose Polymeric Films: Ag(I)-Based Components and Curcumin as Reinforcing Ingredients for Enhanced Food Packaging Properties.

Bio-active ethylcellulose (EC) polymeric films have been obtained by incorporating curcumin (curc) and Ag(I)-based compounds, known for their antioxidant and antimicrobial activity, respectively, within the polymeric matrix. The recently reported Ag(I) coordination polymer, in both its structural forms (α-[(bpy)Ag(OTf)]∞ and ß-{[(bpy)Ag][OTf]}∞), and the [(bpy)Ag(OTf)]∞-curc polymeric co-crystal (bpy=2,2'-bipyridine; OTf=trifluoromethanesulfonate) have been selected as Ag(I) species. The hybrid composite films have been prepared through the simple solvent casting method and characterized through Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM), UV-vis spectroscopy. The deep investigation of the film samples highlighted the non-inert behaviour of EC towards these specific active ingredients. Antimicrobial tests showed that EC films embedding the Ag(I)-based compounds present good antimicrobial performance, in particular against Staphylococcus aureus, used as a model of Gram-positive bacteria. In addition, Silver migration tests, performed on the Ag(I)-incorporating EC films, evidenced low values of silver release particularly in the case of the EC films incorporating [(bpy)Ag(OTf)]∞-curc.

Nanofabrication of Losartan Potassium Sustained Release Floating Microspheres Using Different Grades of Ethyl Cellulose and Its Insight on Release Profiles.

INTRODUCTION: A sustained release system for losartan potassium designed to delay its residence time in the stomach through the preparation of solvent evaporation technique-based floating microspheres. The influence of the different grades of Ethocel™ such as 4 cps, 10 cps, and 22 cps as well as the drug: polymer ratio on various properties of microspheres were tested. METHODS: Thermal and functional analysis revealed no interaction between the encapsulated drug and polymer. The results indicated that the mean diameter of microspheres increased with a change in grades of ethyl cellulose relating to viscosity. However, the drug incorporation efficiency within ethyl cellulose microspheres decreased with increasing viscosity of ethyl cellulose. RESULTS: The bulk density of the formulations was proportionally dependent on concentration and the viscosity of the polymer, which resulted in a decrease in floating capacity from 90.02% to 73.58%. Moreover, the drug release was indirectly proportional to the viscosity of ethyl cellulose tested. The in vitro release profile exhibited a burst effect with a biphasic release pattern following Fickian diffusion, indicating a diffusioncontrolled release mechanism. CONCLUSION: The results demonstrated that the viscosity of ethyl cellulose significantly affects the floating capacity and drug release pattern from microspheres.

A Novel Intrauterine Device for the Spatio-Temporal Release of Norethindrone Acetate as a Counter-Estrogenic Intervention in the Genitourinary Syndrome of Menopause.

The genitourinary syndrome of menopause (GSM) is a widely occurring condition affecting millions of women worldwide. The current treatment of GSM involves the use of orally or vaginally administered estrogens, often with the risk of endometrial hyperplasia. The utilization of progestogens offers a means to counteract the effects of estrogen on the endometrial tissue, decreasing unwanted side effects and improving therapeutic outcomes. In this study, a norethindrone acetate (NETA)-loaded, hollow, cylindrical, and sustained release platform has been designed, fabricated, and optimized for implantation in the uterine cavity as a counter-estrogenic intervention in the treatment of GSM. The developed system, which comprises ethyl cellulose (EC) and polycaprolactone (PCL), has been statistically optimized using a two-factor, two-level factorial design, with the mechanical properties, degradation, swelling, and in vitro drug release of NETA from the device evaluated. The morphological characteristics of the platform were further investigated through scanning electron microscopy in addition to cytocompatibility studies using NIH/3T3 cells. Results from the statistical design highlighted the platform with the highest NETA load and the EC-to-PCL ratio that exhibited favorable release and weight loss profiles. The drug release data for the optimal formulation were best fitted with the Peppas-Sahlin model, implicating both diffusion and polymer relaxation in the release mechanism, with cell viability results noting that the prepared platform demonstrated favorable cytocompatibility. The significant findings of this study firmly establish the developed platform as a promising candidate for the sustained release of NETA within the uterine cavity. This functionality serves as a counter-estrogenic intervention in the treatment of GSM, with the platform holding potential for further advanced biomedical applications.

A new strategy for the treatment of middle ear infection using ciprofloxacin/amoxicillin-loaded ethyl cellulose/polyhydroxybutyrate nanofibers.

A middle ear infection occurs due to the presence of several microorganisms behind the eardrum (tympanic membrane) and is very challenging to treat due to its unique location and requires a well-designed treatment. If not treated properly, the infection can result in severe symptoms and unavoidable side effects. In this study, excellent biocompatible ethyl cellulose (EC) and biodegradable polyhydroxybutyrate (PHB) biopolymer were used to fabricate drug-loaded nanofiber scaffolds using an electrospinning technique to overcome antibiotic overdose and insufficient efficacy of drug release during treatment. PHB polymer was produced from Halomonas sp., and the purity of PHB was found to around be 90 %. Additionally, ciprofloxacin (CIP) and amoxicillin (AMX) are highly preferable since both drugs are highly effective against gram-negative and gram-positive bacteria to treat several infections. Obtained smooth nanofibers were between 116.24 and 171.82 nm in diameter and the addition of PHB polymer and antibiotics improved the morphology of the nanofiber scaffolds. Thermal properties of the nanofiber scaffolds were tested and the highest Tg temperature resulted at 229 °C. The mechanical properties of the scaffolds were tested, and the highest tensile strength resulted in 4.65 ± 6.33 MPa. Also, drug-loaded scaffolds were treated against the most common microorganisms that cause the infection, such as S.aureus, E.coli, and P.aeruginosa, and resulted in inhibition zones between 10 and 21 mm. MTT assay was performed by culturing human adipose-derived mesenchymal stem cells (hAD MSCs) on the scaffolds. The morphology of the hAD MSCs' attachment was tested with SEM analysis and hAD MSCs were able to attach, spread, and live on each scaffold even on the day of 7. The cumulative drug release kinetics of CIP and AMX from drug-loaded scaffolds were analysed in phosphate-buffered saline (pH: 7.4) within different time intervals of up to 14 days using a UV spectrophotometer. Furthermore, the drug release showed that the First-Order and Korsmeyer-Peppas models were the most suitable kinetic models. Animal testing was performed on SD rats, matrix and collagen deposition occurred on days 5 and 10, which were observed using Hematoxylin-eosin and Masson's trichrome staining. At the highest drug concentration, a better repair effect was observed. Results were promising and showed potential for novel treatment.

A novel colormetric and light-up fluorescent sensor from flavonol derivative grafted cellulose for rapid and sensitive detection of Hg2+ and its applications in biological and environmental system.

Mercury ion (Hg2+) is one of harmful heavy metal ions that can accumulate inside the human organism and cause some health problems. In the article, a highly effective fluorescent probe named EC-T-PCBM was prepared by grafting flavonol derivatives onto ethyl cellulose for the specific recognition of Hg2+. EC-T-PCBM exhibited a remarkable fluorescence light-up response toward Hg2+ with excellent sensitivity. EC-T-PCBM possessed several prominent sensing properties for Hg2+, such as low detection limit (43.9 nM), short response time (5 min), and wide detection pH range (6-9). The response mechanism of EC-T-PCBM to Hg2+ has been verified through 1H NMR titration and DFT computation. Additionally, EC-T-PCBM not only can be used for accurately determining trace amount of Hg2+ in actual environmental water samples, but also can serve as a portable and rapid device by loading it on test strips for sensitive and selective visualization of Hg2+. More importantly, the confocal fluorescence imaging of onion cells suggested the favorable cell membrane permeability of EC-T-PCBM and its prominent ability to continuously monitor the enrichment from Hg2+ within fresh plant tissues.

Determining the Relationship between Delivery Parameters and Ablation Distribution for Novel Gel Ethanol Percutaneous Therapy in Ex Vivo Swine Liver.

Ethyl cellulose-ethanol (ECE) is emerging as a promising formulation for ablative injections, with more controllable injection distributions than those from traditional liquid ethanol. This study evaluates the influence of salient injection parameters on forces needed for infusion, depot volume, retention, and shape in a large animal model relevant to human applications. Experiments were conducted to investigate how infusion volume (0.5 mL to 2.5 mL), ECE concentration (6% or 12%), needle gauge (22 G or 27 G), and infusion rate (10 mL/h) impacted the force of infusion into air using a load cell. These parameters, with the addition of manual infusion, were investigated to elucidate their influence on depot volume, retention, and shape (aspect ratio), measured using CT imaging, in an ex vivo swine liver model. Force during injection increased significantly for 12% compared to 6% ECE and for 27 G needles compared to 22 G. Force variability increased with higher ECE concentration and smaller needle diameter. As infusion volume increased, 12% ECE achieved superior depot volume compared to 6% ECE. For all infusion volumes, 12% ECE achieved superior retention compared to 6% ECE. Needle gauge and infusion rate had little influence on the observed depot volume or retention; however, the smaller needles resulted in higher variability in depot shape for 12% ECE. These results help us understand the multivariate nature of injection performance, informing injection protocol designs for ablations using gel ethanol and infusion, with volumes relevant to human applications.

Exploring temperature-responsive drug delivery with biocompatible fatty acids as phase change materials in ethyl cellulose nanofibers.

This study introduces a novel temperature-responsive drug delivery system using ethyl cellulose (EC) nanofibers encapsulating a eutectic mixture of lauric acid/stearic acid (LA/SA) as phase change materials (PCMs) and Rhodamine B (RhB) as a model drug. Employing blend electrospinning, the nanofibers achieved controlled drug release responsive to temperature changes. The peak shift of the carbonyl group in FTIR analysis confirmed drug-polymer compatibility, while the absence of RhB peaks in the XRD and DSC assessments revealed RhB's amorphous distribution within the fibers. Our findings demonstrate that RhB release is dependent on its loading, with a slow initial release (<2 %) for 1 % and 5 % RhB loadings and a burst release (~12 %) for 10 % loading. Notably, the release rate was tunable at 37 °C by adjusting LA/SA concentration. The optimal LA/SA loading for temperature-responsive release is identified as 10 %. Over 240 h, there is a 32 % increase in RhB release at 37 °C, and an additional 8 % increase at 40 °C, compared to 25 °C. This research illustrates the potential of PCM-integrated nanofibers in smart drug delivery, particularly for chemotherapy, antibiotics, and anti-inflammatory drugs, showcasing an innovative approach to improving therapeutic efficiency while reducing side effects.

Safety of a feed additive consisting of ethyl cellulose for all animal species (Association Management & Regulatory Services Ltd).

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of ethyl cellulose as a technological feed additive for all animal species. In its previous opinions on the safety and efficacy of the product, the FEEDAP Panel could not conclude on proper identification and characterisation as required for a feed additive. The occurrence of potential toxic impurities could also not be assessed. Based on the new data provided, the feed additive ethyl cellulose was properly identified and characterised and was shown to meet the specifications set for the food additive. Therefore, the conclusions of the safety assessment reached in the previous opinions for ethyl cellulose meeting the food additive specifications, apply to the ethyl cellulose under assessment as a feed additive. The feed additive is considered safe for all animal species, the consumer and the environment. In the absence of data, the FEEDAP Panel is not in the position to conclude on the safety for the user.

Ethyl Cellulose-Core, OSA Starch-Shell Electrosprayed Microcapsules Enhance the Oxidative Stability of Loaded Fish Oil.

The encapsulation and the oxidative stability of cod liver fish oil (CLO) within coaxial electrosprayed (ethyl cellulose/CLO) core-(octenyl succinic anhydride, OSA-modified starch) shell, and monoaxial electrosprayed ethyl cellulose/CLO microcapsules were investigated. Core-shell (H-ECLO) and monoaxial (ECLO) electrosprayed microcapsules with an average diameter of 2.8 ± 1.8 µm, and 2.2 ± 1.4 µm, respectively, were produced. Confocal microscopy confirmed not only the core-shell structure of the H-ECLO microcapsules, but also the location of the CLO in the core. However, for the ECLO microcapsules, the CLO was distributed on the microcapsules' surface, as also confirmed by Raman spectroscopy. Atomic force microscopy showed that the average surface adhesion of the H-ECLO microcapsules was significantly lower (5.41 ± 0.31 nN) than ECLO microcapsules (18.18 ± 1.07 nN), while the H-ECLO microcapsules showed a remarkably higher Young's modulus (33.84 ± 4.36 MPa) than the ECLO microcapsules (6.64 ± 0.84 MPa). Differential scanning calorimetry results confirmed that the H-ECLO microcapsules enhanced the oxidative stability of encapsulated CLO by about 15 times, in comparison to non-encapsulated oil, mainly by preventing the presence of the fish oil at the surface of the microcapsules, while ECLO microcapsules enhanced the oxidative stability of CLO about 2.9 times due to the hydrophobic interactions of the oil and ethyl cellulose. Furthermore, the finite element method was also used to evaluate the electric field strength distribution, which was substantially higher in the vicinity of the collector and lower in the proximity of the nozzle when the coaxial electrospray process was employed in comparison to the monoaxial process.

Electrical Conduction Mechanisms in Ethyl Cellulose Films under DC and AC Electric Fields.

This work reports the dielectric behavior of the biopolymer ethyl cellulose (EC) observed from transient currents experiments under the action of a direct current (DC) electric field (~107 V/m) under vacuum conditions. The viscoelastic response of the EC was evaluated using dynamic mechanical analysis (DMA), observing a mechanical relaxation related to glass transition of around ~402 K. Furthermore, we propose a mathematical framework that describes the transient current in EC using a fractional differential equation, whose solution involves the Mittag-Leffler function. The fractional order, between 0 and 1, is related to the energy dissipation rate and the molecular mobility of the polymer. Subsequently, the conduction mechanisms are considered, on the one hand, the phenomena that occur through the polymer-electrode interface and, on the other hand, those which manifest themselves in the bulk material. Finally, alternating current (AC) conductivity measurements above the glass transition temperature (~402 K) and in a frequency domain from 20 Hz to 2 MHz were carried out, observing electrical conduction described by the segmental movements of the polymeric chains. Its electrical properties also position EC as a potential candidate for electrical, electronics, and mechatronics applications.

Carbon-Based Composites with Biodegradable Matrix for Flexible Paper Electronics.

The authors explore the development of paper-based electronics using carbon-based composites with a biodegradable matrix based on ethyl cellulose and dibasic ester solvent. The main focus is on screen-printing techniques for creating flexible, eco-friendly electronic devices. This research evaluates the printability with the rheological measurements, electrical properties, flexibility, and adhesion of these composites, considering various compositions, including graphene, graphite, and carbon black. The study finds that certain compositions offer sheet resistance below 1 kΩ/sq and good adhesion to paper substrates with just one layer of screen printing, demonstrating the potential for commercial applications, such as single-use electronics, flexible heaters, etc. The study also shows the impact of cyclic bending on the electrical parameters of the prepared layers. This research emphasizes the importance of the biodegradability of the matrix, contributing to the field of sustainable electronics. Overall, this study provides insights into developing environmentally friendly, flexible electronic components, highlighting the role of biodegradable materials in this evolving industry.

Application of 32 factorial design for loratadine-loaded nanosponge in topical gel formulation: comprehensive in-vitro and ex vivo evaluations.

Loratadine (LoR) is a highly lipophilic and practically insoluble in water, hence having a low oral bioavailability. As it is formulated as topical gel, it competitively binds with the receptors, thus reducing the side-effects. The objective of this study was to prepare LoR loaded nanosponge (LoR-NS) in gel for topical delivery. Nine different formulations of emulsion were prepared by solvent evaporation method with polyvinyl alcohol (PVA), ethyl cellulose (EC), and dichloromethane (DCM). Based on 32 Full Factorial Design (FFD), optimization was carried out by varying the concentration of LOR:EC ratio and stirring rate. The preparations were subjected for the evaluation of particle size (PS), in vitro release, zeta potential (ZP) and entrapment efficiency (EE). The results revealed that the NS dispersion was nanosized with sustained release profiles and significant PS. The optimised formulation was formulated and incorporated into carbopol 934P hydrogel. The formulation was then examined to surface morphological characterizations using scanning electron microscopy (SEM) which depicted spherical NS. Stability studies, undertaken for 2 months at 40 ± 2 °C/75 ± 5% RH, concluded to the stability of the formulation. The formulation did not cause skin irritation. Therefore, the prepared NS hydrogel proved to be a promising applicant for LoR as a novel drug delivery system (NDDS) for safe, sustained and controlled topical application.

Cholesteric Liquid Crystals with Thermally Stable Reflection Color from Mixtures of Completely Etherified Ethyl Cellulose Derivative and Methacrylic Acid.

Cellulose derivatives have attracted attention as environmentally friendly materials that can exhibit a cholesteric liquid crystal (CLC) phase with visible light reflection. Previous reports have shown that the chemical structures and the degrees of substitution of cellulose derivatives have significant influence on their reflection properties. Although many studies have been reported on CLC using ethyl cellulose (EC) derivatives in which the hydroxy groups are esterified, there have been no studies on EC derivatives with etherified side chains. In this article, we optimized the Williamson ether synthesis to introduce pentyl ether groups in the EC side chain. The degree of substitution with pentyl ether group (DSPe), confirmed via 1H-NMR spectroscopic measurements, was controlled using the solvent and the base concentration in this synthesis. All the etherified EC derivatives were soluble in methacrylic acid (MAA), allowing for the preparation of lyotropic CLCs with visible reflection. Although the reflection peak of lyotropic CLCs generally varies with temperature, the reflection peak of lyotropic CLCs of completely etherified EC derivatives with MAA could almost be preserved in the temperature range from 30 to 110 °C even without the aid of any crosslinking. Such thermal stability of the reflection peak of CLCs may be greatly advantageous for fabricating new photonic devices with eco-friendliness.

An ultrasensitive cellulose-based fluorescent sensor for Al3+ detection and its applications in plant tissue and food samples.

Fluorescent sensors available for metal ions detection have been extensively developed in recent years. However, developing an ultrasensitive fluorescent sensor for highly selectively detecting Al3+ based on cellulose remains a challenge. In this study, an ethylcellulose-based flavonol fluorescent sensor named EC-BHA was synthesized by the esterification of ethylcellulose (EC) with a new flavonol derivative 4-(2-(2,3-bis(ethoxymeothy)phenyl)-3-hydroxy-4-oxo-4-H-chromen-7-yl) benzoic acid (BHA). The fluorescence intensity of EC-BHA exhibited a 180-fold increase at 490 nm after binding with Al3+ and provided an ultralow detection limit of 13.0 nM. The sensor showed some exceptional sensing properties including a broad pH range (4-10), large Stokes shifts (190 nm), and a short response time (3 min). This sensor was successfully applied for determining trace Al3+ in food samples as well as in plant tissue. Moreover, the electrostatic spun film EBP was fabricated by blending EC-BHA with PS (polystyrene) via electrostatic spinning technique and utilized for selective detection of Al3+ as soon as possible.

Ethyl cellulose/gelatin-carboxymethyl chitosan bilayer films doped with Euryale ferox seed shell polyphenol for cooked meat preservation.

This study evaluated the effects of an edible bilayer containing polyphenols from the Euryale ferox seed shell on ready-to-eat cooked beef products, including the physical, mechanical, antioxidant, and antibacterial capabilities. Here, the bilayer films were prepared by layer-by-layer solution pouring using hydrophobic ethyl cellulose (EC) as the outer layer, and hydrophilic gelatin/carboxymethyl chitosan (GC) as the inner layer. By adjusting the proportion of gelatin to carboxymethyl chitosan, the optical, mechanical, and barrier characteristics of bilayer films were markedly enhanced. Extracted polyphenol (EP) from shell of the Euryale ferox seed performed potent antibacterial property against Listeria monocytogenes (L. monocytogenes). The addition of EP to the inner layer of the optimized bilayer film further improved the mechanical and barrier properties of films, and as expected, the film exhibited antioxidant and antibacterial abilities. Additionally, cooked beef and cooked chicken preservation tests indicated that the active bilayer film showed good inhibition of L. monocytogenes and delayed lipid oxidation in ready-to-eat meat products, and significantly delayed the pH, moisture loss, color and texture changes. This study developed multifunctional bilayer active edible films, which has a great potential in the preservation ready-to-eat cooked meat products.

Humidity-adjustable functional gelatin hydrogel/ethyl cellulose bilayer films for active food packaging application.

A sustainable functional bilayer film composed of gelatin hydrogel/ethyl cellulose was fabricated using a simple LBL casting method. The outer layer was hydrophobic ethyl cellulose (EC), while the inner layer was hydrophilic gelatin (GEL) hydrogel. Tannic acid (TA) served as a green cross-linker for GEL hydrogel preparation and as a reductant for AgNPs synthesis in-situ within the hydrogel network. Physicochemical and functional properties of the bilayer films containing different TA content were studied. When 3 wt% TA was added, the AgNPs@GT-3/EC bilayer film exhibited superior UV-light barrier, possessed desirable humidity-adjustable capability and oxygen barrier due to denser hydrogel network structure, and effectively inactivated foodborne pathogens S. aureus and E. coli with bacteriostatic rates of 99 %. The application results indicated that this bilayer film effectively maintained the postharvest quality of white button mushrooms and prolonged their shelf-life to 7 days under ambient storage, demonstrating its promising potential for fresh food packaging.