Oxygen Permeability Research Articles

Room-temperature rapid oxygen monitoring system in high humidity hydrogen gas environment towards water electrolysis application

Water electrolysis is one of the key processes for carbon-free hydrogen (H2) generation, yet it inherently presents the risk of oxygen (O2) permeation, a significant concern that must be addressed. Contrary to external atmospheric conditions, the environment within a water electrolysis system is characterized exclusively by high-purity H2, little O2, and moisture (H2O). However, there has been limited research on sensors capable of detecting O2 crossover in such a pure H2 atmosphere under high humidity conditions. In this study, we developed an electrolysis O2 monitoring (E-OM) sensor based on a semiconducting metal oxide (SMO) that can operate at a room-temperature with such high humidity through photoactivation with 365 nm LED light. A porous In2O3 nanofilm, prepared by glancing angle deposition (GLAD), was used as the gas sensing material, and copper nanoparticles (Cu NPs) were decorated on the In2O3 surface through electron beam evaporation to accelerate the O2 adsorption. Remarkably, the E-OM sensor showed a humidity-independent response to O2 gas in the H2 atmosphere. Meanwhile, since the response of the E-OM sensor itself was not fast enough for water electrolysis system application, convolutional neural network (CNN)-based signal processing in the time domain was applied. As a result, our E-OM sensor system could predict O2 concentrations from 0 to 2 vol% in an H2 environment with a relative humidity (RH) of 30–90 %, and the detection time was under 5 s. This development could enable safe, rapid, and cost-effective monitoring of O2 crossover in H2 production infrastructure.

A Study on Overcoming Post-TACE Drug Resistance in HCC Based on Controllable Oxygen Release-Magnetic Hyperthermia Therapy.

Drug-eluting bead transcatheter arterial chemoembolization (D-TACE) is one of the first-line treatment for intermediate hepatocellular carcinoma (HCC). However, the dual hypoxia microenvironment, due to inherent tumor hypoxia and TACE-induced hypoxia, triggers drug resistance in HCC. To address this challenge, the study develops multicavitary microspheres capable of encapsulating oxygen and harnessing magnetic hyperthermia to enhance oxygen permeability. The novel multicavitary oxygen-encapsulated magnetothermal drug-eluting microspheres (OTD-Ms) effectively reduce hypoxia-related proteins (HIF-1α, VEGF-A) and drug resistance (P-gp) both in vitro and in vivo. Moreover, these microspheres demonstrate improved TACE efficacy and enhance survival rates in a rabbit VX-2 tumor model, suggesting their potential for HCC treatment.

Controlled localization of graphene oxide to improve barrier, biodegradation and mechanical properties of PBAT/EVOH

AbstractIncorporating graphene oxide (GO) with controlled localization into poly(butylene adipate‐co‐terephthalate) (PBAT) blends with poly(ethylene vinyl alcohol) (EVOH) aimed to improve barrier properties, biodegradability, and mechanical strength of PBAT. The PBAT/EVOH/GO nanocomposites containing 0 to 1 wt% of GO were prepared by a reactive mixing process in internal mixer. Microscopic images confirmed that the GO nanoplatelets are mainly localized in PBAT phase and then at the interface, contrary to the thermodynamic affinity of GO toward EVOH. The reactive nature of PBAT/EVOH/GO nanocomposites was confirmed via time‐sweep rheological studies where specific changes were observed in melt viscosity over time. The results of microscopic studies, rheometry, tensile test, and dynamic mechanical thermal analysis (DMTA) confirmed that localizing GO at the interface establishes strong interactions between PBAT and EVOH. By the addition of 0.75 wt% GO, tensile and yield strength were improved by 19% and 45%, respectively. Increasing GO significantly increased the hydrolysis degradation rate of the nanocomposites. Furthermore, the addition of GO considerably decreased the oxygen and water vapor permeability of the blends by up to 40% at 1 wt% GO.

Design of CO2-Resistant High-Entropy Perovskites Based on Ba0.5Sr0.5Co0.8Fe0.2O3-δ Materials.

High-entropy perovskite materials (HEPMs), characterized by their multi-element composition and highly disordered structure, can incorporate multiple rare earth elements at the A-site, producing perovskites with enhanced CO2 resistance, making them stay high performance and structurally stable in the CO2 atmosphere. However, this modification may result in reduced oxygen permeability. In this study, we investigated La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.8Fe0.2O3-δ (L0.2M1.8) high-entropy perovskite materials, focusing on enhancing their oxygen permeability in both air and CO2 atmospheres through strategic design modifications at the B-sites and A/B-sites. We prepared Ni-substituted La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.2M1.7N0.1) HEPMs by introducing Ni elements at the B-site, and further innovatively introduced A-site defects to prepare La0.2Pr0.2Nd0.2Ba0.2Sr0.2Co0.7Fe0.2Ni0.1O3-δ (L0.1M1.7N0.1) materials. In a pure CO2 atmosphere, the oxygen permeation flux of the L0.1M1.7N0.1 membrane can reach 0.29 mL·cm-2·min-1. Notably, the L0.1M1.7N0.1 membrane maintained a good perovskite structure after stability tests extending up to 120 h under 20% CO2/80% He atmosphere. These findings suggest that A-site-defect high-entropy perovskites hold great promise for applications in CO2 capture, storage, and utilization.

Fabrication and characterization of novel biodegradable films based on tomato seed mucilage and gelatin plasticized with polyol mixtures

This research evaluates the potential of tomato seed mucilage (TSM) –gelatin (Ge) in producing edible films. Edible films were made using various ratios of TSM to Ge (1:0, 0.33:0.66, 0.66:0.33, and 0:1). Moreover, the effects of including three types of plasticizers, namely, glycerol (Gly), sorbitol (Sor), and polyethylene glycol (PEG) were investigated. The findings indicated that adding Ge did not affect the thickness of the films (p>0.05). However, it significantly increased the tensile strength (TS) and Young's modulus while reducing the elongation at break (EB) (p˂0.05). A higher TSM ratio significantly increased total color difference (ΔE) and yellowness index while decreasing film lightness and whiteness index (WI) (p˂0.05). The contact angle significantly decreased with the TSM ratio increases and Ge decreases (p˂0.05). Moreover, this led to higher opacity, solubility, moisture content, oxygen permeability, water vapor permeability (WVP), swelling, and moisture absorption (p˂0.05). Adding a plasticizer had no effect on the films' opacity, contact angle, and thickness. The Gly-containing film featured the highest EB, solubility, moisture content, swelling, WVP, oxygen permeability, and moisture absorption. The Sor-containing film had the highest TS. TSM concentration was directly correlated with increased film heterogeneity and surface roughness. X-ray diffraction peaks became sharper by increasing TSM concentration and including PEG, while Gly inclusion produced ordered broad peaks.

Effect of chlorine dioxide (ClO2) combined with different oxygen permeability package treatments on postharvest antioxidant activity and storage life of ‘Liaofeng’ grapes

To enhance the storage quality of ‘Liaofeng’ grapes, this research employed chlorine dioxide in collaboration with different package of preservative bags to explore its preservative effect on ‘Liaofeng’ grapes. After fumigating the grapes with 300 mg L−1 ClO2 solution, the control group was packaged in unpacked and PE bags, while the treatment group was packaged in three kinds of bags with different oxygen permeability, and stored in 4 °C and relative humidity controlled at 90%–95% for 90 days. The results showed that ClO2-GB package treatment significantly delayed the decline of grape hardness (P < 0.05), and decreased the weight loss, threshing, decay and peduncle browning index after storage for 90 days. ClO2-GB package treatment not only diminishes the levels of soluble solids content, titrable acidity, ascorbic acid and glutathione but also effectively suppresses the respiration rate in fruits. The contents of total phenols, flavonoids, anthocyanins and reduced glutathione after ClO2-GB treatment were significantly higher than those in unpackaged group (P < 0.05), and curbed the increase in relative electrical conductivity and malondialdehyde concentration. In comparison to ClO2-YTB and ClO2-YB treatments, ClO2-GB treatment demonstrated superior efficacy in modulating the antioxidant metabolism of grapes. It notably elevated the enzymatic activities of catalase, superoxide dismutase, ascorbate peroxidase, and glutathione reductase, while inhibiting the activities of peroxidase and polyphenol oxidase. The quality assessment of ‘Liaofeng’ grapes after 90 d storage period, conducted through principal component analysis (PCA), yielded the following ranking: ClO2-GB > ClO2-YB > ClO2-YTB > ClO2-PE > ClO2. This suggests that 300 mg L−1 ClO2 fumigation combined with different package treatments was more beneficial to the storage of ‘Liaofeng’ grape. ClO2-GB package treatment emerged as the most advantageous.

Dual cross-linked network of the active starch film by incorporating palmitic acid and geraniol: A comprehensive evaluation of the hydrophobic mechanism and antimicrobial activity

In this study, (3-Aminopropyl) triethoxysilane (APTES) was employed as a bridging agent to enhance the compatibility between the hydrophilic starch/pectin film and the hydrophobic palmitic acid (PA) coating through hydrogen bonding and chemical reactions. To address the insufficient antibacterial activity of starch films, geraniol was also incorporated. The intermolecular interactions among APTES, PA, and starch were confirmed using x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and hydrogen nuclear magnetic resonance spectroscopy (1H NMR). Notably, the inclusion of APTES and PA significantly increased the film's hydrophobicity, resulting in a water contact angle (WCA) of 95.12°, a water vapor permeability (WVP) of 2.08 × 10−10 g/(mm·s·Pa), and an oxygen permeability (OP) of 2.61 × 10−9 g·mm·mm−2·s−1. Molecular dynamics (MD) simulations revealed strong non-covalent interactions and exceptional compatibility between starch and PA. Furthermore, the integration of pectin and geraniol improved the mechanical strength and antimicrobial properties of the modified films compared to unmodified starch films. These environmentally friendly and biodegradable starch-based films present a promising option for sustainable packaging materials in food preservation.

Glucose-responsive carboxymethyl chitosan/ sodium alginate film protects against mechanical wound on postharvest blueberry

Fresh fruits and vegetables, particularly berries, are highly susceptible to mechanical damage, which results in nutrient loss, reduced quality, and increased decay from microbial infections, ultimately leading to significant losses. Here, a biodegradable polysaccharide film was employed to encapsulate glucose oxidase (Gox), thereby creating a glucose/wounding-responsive active package that reduced fruit respiration, promoted healing and protected blueberry wounds from mold infection. The combination of carboxymethyl chitosan and sodium alginate resulted in the formation of the polysaccharides film CSF that effectively restricted the permeation of oxygen, water, and carbon dioxide around the surface of the fruit. The encapsulation of Gox in the CSF film (CSFG) reduced glucose levels through enzymatic reaction in surface wounds of the fruit, thereby competing for glucose to establish a starvation-like microenvironment for the pathogenic fungus Botrytis cinerea. The enzymatic reaction also facilitated the production of hydrogen peroxide, which functioned as a fungicide that inhibits the growth of B. cinerea and served as a secondary messenger in fruit immunity. The CSFG film increased beta-glucanase activity, and decreased lipid peroxidation in wounds of blueberries. Therefore, this glucose-responsive CSFG barrier significantly reduced the decay rates of gray mold, caused by B. cinerea in wounded blueberries, by 66.7% compared to the control at 6 d of storage. Taken together, the glucose-responsive active packaging film provides an alternative package for safeguarding blueberries against mechanical damage.

Effects of copper doping on microstructural evolution and oxygen permeability of Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe1-xCuxO3-δ dual-phase oxygen permeable membranes

Ce0.8Sm0.2O2-δ(wt.70 %)-Sm0.6Sr0.4Fe1-xCuxO3-δ(wt.30 %) (SDC-SSFC) dual-phase oxygen permeable membranes were prepared by one-pot EDTA-citric acid combined complexing method. Effects of copper doping content on crystallographic phase, microstructure and oxygen permeability were deeply investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDXS). Systematic studies reveal that SDC as oxygen ion conductors and SSFC as electron conductor display an excellent synergistic effect only if a suitable doping content of copper was adopted. It can be found that Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ exhibits the highest oxygen permeation flux of up to about 0.61 ml cm−2 at 950 °C and lower oxygen permeation activation energy, which displays nearly a two-fold increase in oxygen permeability compared with the sample without any copper doping. If the copper doping content in B-site of SSFC perovskite exceeds about 30 %, a third phase, i.e., CuO, would appear in the bulk of SDC-SSFC dual-phase membrane and the grain size of CuO tend to gradually increase which would degrade the oxygen permeability of SDC-SSFC dual-phase membrane. Kinetical analysis showed that the critical membrane thickness (Lc) of Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ membrane is close to approximately 0.6 mm, i.e., if the membrane thickness is larger than 0.6 mm, its rate-determining step would transform into the bulk-diffusion exchange from surface exchange. Meanwhile, Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ membrane exhibits a stable oxygen permeation flux of up to 0.32 ml cm−2·min−1 in pure CO2 atmosphere for more than 120 h without any degradation.

Application of testicular organ culture system for the evaluation of spermatogenesis impairment

Recently, it was reported that a testicular organ culture system (TOCS) using polydimethylsiloxane (PDMS) chips with excellent oxygen permeability and biocompatibility, called the PDMS-chip ceiling (PC) method, enables improved spermatogenesis efficiency. We investigated whether this PC method is useful for detecting impaired spermatogenesis caused by busulfan (Bu), a typical testicular toxicant. In this study, testicular tissue fragments from Acro3-EGFP mice, which express the green fluorescent protein (GFP) and reflect the progression of spermatogenesis, were subjected to the PC method. When treated with Bu, cultured tissues shrank in volume, and their GFP-expressing area decreased or disappeared. Histological examination confirmed the regression of spermatogenesis. In addition, immunohistochemical examination revealed that spermatogonia, including spermatogonial stem cells (SSCs), were the primary targets of Bu toxicity. Time-course analysis demonstrated that the recovery of spermatogenesis, dependent on Bu concentration, correlated closely with the severity of damage to these target cells. These results suggest that the PC method is a useful approach for detecting spermatogenesis impairment accurately through faithful recapitulation of spermatogenesis in vivo.

Characterizations of the pullulan/sodium alginate coatings incorporated with sodium silicate and EDTA-2Na and the antifungal effect on citrus green mold

Citrus has suffered great losses from postharvest fungal diseases. The strategy of polysaccharide-based coating combined with antimicrobial salts was introduced to preserve citrus and control green mold. Sodium silicate and ethylene diamine tetraacetic acid-2Na (EDTA-2Na) (SE) were incorporated with pullulan (PUL)/sodium alginate (SA) solutions to fabricate PSA-SE systems. The results indicated that the PSA-SE films had good biocompatibility based on hydrogen bonds and showed uniform and dense. The molecular of PUL and SA were assembled through entanglement to form a network structure and the surface roughness of the PSA-SE films increased with the addition of SA. The P3SA2-SE film indicated appropriate tensile strength and elongation at break, as well as the lowest water vapor permeability. The carbon dioxide and oxygen permeability and dissolution of P3SA2-SE film were at low values. The P3SA2-SE film had the highest water contact angle (66°). With the addition of SA, the absorbance of the PSA-SE films increased, which was conducive to light blocking. The antifungal experiments revealed that the P3SA2-SE coating showed a significant effect on controlling citrus green mold, especially in Citrus sinensis Osbeck ‘Lane Late’ almost completely inhibited Penicillium digitatum (P44). This study will promote the development of citrus postharvest disease control.

Dual effect of pH and X-ray irradiation on properties of gelatin/trans-cinnamaldehyde-based composite films for sustainable packaging

Gelatin (Gel) based water-insoluble films with antimicrobial properties were developed by the green method using trans-cinnamaldehyde (TCA) and low-energy X-ray irradiation as dual crosslinkers. The Gel/TCA composite films (GTCF) were prepared at different pH (4, 6, 8, and 10) and crosslinked by incorporating 5 % (w/w, based on Gel) TCA and X-ray irradiation (350 kV and 11.4 mA) with doses of 0, 5, 10 and 15 kGy. The presence of TCA in GTCF forms dense, flexible, and strong films when exposed to X-ray irradiation. The GTCF at pH 6, incorporated with 5 wt% TCA and irradiated with 10 kGy X-ray, displayed the highest degree of crosslinking (DOC) (93.4 ± 3.4 %), tensile strength, excellent UV-barrier (> 99.9 %), antimicrobial (inhibitory capacity of >50 %), and water vapor permeability (4.1 ± 0.6 g.mm/m2.day. kPa), and low solubility in water (0.5 ± 0.3 %), and oxygen permeability. The GTCF, crosslinked with X-ray irradiation, has multifunctional properties and strong potential in the sustainable packaging industry to augment the shelf life of food and reduce food waste. To the best of our information, this is the first and novel report investigating the effects of pH on the properties of GTCF crosslinked with X-ray.

Delaying walnut oxidation using a compostable film comprising poly(ε-caprolactone), thermoplastic gliadins, and green tea extract

A new active packaging composed of poly(e-caprolactone) (PCL) and thermoplastic gliadin proteins incorporating green tea extract (GTE) was developed through compounding and film-extrusion process. Firstly, commercial green tea extract was analyzed, revealing that GTE primarily comprised epigallocatechin gallate (EGCG), which conferred potent antioxidant activity determined by the DPPH assay, along with moderate antibacterial activity. The incorporation of 5 wt% of GTE in the extruded films increased thermal stability and Young’s Modulus, and reduced oxygen and water vapor permeability with respect to control PCL/TPG film. Migration studies showed that the release of GTE depended on the type of food simulant, with higher levels observed in an oil-in-water emulsion simulant compared to a non-acidic aqueous food simulant, while no migration of GTE components was detected in dry foodstuffs simulant. Consequently, the antioxidant capacity derived from migrated GTE components were considerably higher in 50 % ethanol than in 10 % ethanol. Furthermore, PCL/TPG-GTE film exhibited antibacterial activity against Gram negative E. coli and Gram positive S. aureus in vitro when tested following the JIS Z2801 standard. The GTE addition also improved walnuts stability, resulting in a reduction and delay of fat peroxidation. Hence, the novel active system developed in this work can constitute a sustainable alternative to improve quality and safety of packaged products.

Recovery and characterization of cellulose microfibers from fallen leaves and evaluation of their potential as reinforcement agents for production of new biodegradable packaging materials.

In the present work, cellulose microfibers (CMFs) isolated from fallen autumn leaves of cherry plum (Prunus cerasifera pissardii nigra), white mulberry (Morus alba) and plane (Platanus orientalis) trees were characterized and used as reinforcement agents in sodium alginate-based biodegradable films. Fourier transform infrared spectroscopy (FT-IR) characterization showed that the CMFs were successfully isolated from the leaves with high purity. The extracted CMFs had a particle size ranging from 321.20 nm to 632.26 nm and negative zeta potential values (-27.33 to -21.40). The extraction yield of CMFs ranged from 19.53% to 26.00%. Incorporation of the leaf-derived CMFs into sodium alginate based films (1%, w:w) increased their tensile strength (from 153.73 to 187.78 MPa) and elongation at break values (from 105.97% to 89.90%) and significantly decreased oxygen (from 121.46 to 75.56 meq kg-1) and water vapor permeabilities (from 2.36 to 1.60 g mm h-1 m-2 kPa-1)(p < 0.05). Furthermore, the supplementation of CMFs into the biopolymer matrix had no significant effect on the color (L*: 85.35-85.67; a*: -0.75-0.71; b*: 4.23-4.94) and moisture content (44.64-48.42%) of the film samples, although the thickness increased (40.33-94.66 μm). Scanning electron microscopy (SEM) images showed that CMFs were homogeneously dispersed in the film matrix. Overall, this study confirms that fallen cherry plum, white mulberry, and plane leaves are valuable sources of CMFs which could be used in the manufacturing of biodegradable nanocomposite films as reinforcement agents.

Regenerated cellulose films with controllable microporous structure for enhanced seed germination

In this work, the preparation of high-performance and porous regenerated cellulose (RCNH) films for seed germination application were investigated. The films were prepared from bamboo-based cellulose carbamate-NaOH/ZnO/urea and coagulated using environmentally friendly aqueous solution of (NH4)2SO4. The results showed that the pore size of the films could be efficiently controlled by changing the concentration and temperature of the coagulation bath. In a mild environment, the system remains undisturbed, resulting in slow diffusion between the solvent and coagulation bath. This allows for the cellulose molecular chains to align in parallel and self-aggregate, forming a three-dimensional network structure. Therefore, the best mechanical properties were demonstrated by a film coagulated using 5 wt% (NH4)2SO4 solution at 10 °C. This film showed excellent tensile strength of 108 MPa and high elongation at break (35 %). As compared to a plastic wrap, the film demonstrated higher permeability for oxygen, and a moisture retaining ability. Due to these properties, it could be used as an agricultural film to encase and promote the growth of mung bean seeds. Moreover, the film was biodegradable with a short decomposition time, losing 90.75 % of its original mass after 63 days. In a summary, this work provides a route for robust, biodegradable, and permeable regenerated cellulose films with potential applications as biodegradable agricultural mulches.

Pomegranate peel extract incorporated soy protein isolate/Artemisia sphaerocephala Krasch. gum composite films for fresh-cut apples preservation

The objective of this study was to prepare an active packaging film using phosphorylated soy protein isolate (PPS) and Artemisia sphaerocephala Krasch. gum (ASKG) as film matrices, with the incorporation of pomegranate peel extract (PPE) to preserve fresh-cut apples. The results showed that PA-PPE (PPS/ASKG-PPE) films significantly increased thickness by 24.47 %, tensile strength by 58.76 %, and elongation at break by 30.48 %. Additionally, water vapor permeability and oxygen permeability decreased significantly to 6.17 × 10−13 and 0.62 × 10−13 Kg•m•m−2•s−1•Pa−1, respectively. FTIR, XRD, and SEM analyses confirmed the formation of intermolecular hydrogen bonds between PPS, ASKG, and polyphenols extracted from pomegranate peel, indicating excellent compatibility. Furthermore, radical scavenging activity experiments demonstrated that these films exhibited a remarkable ability to scavenge DPPH and ABTS+ radicals up to 70.44 % and 74.28 %, respectively, when the PPE content was at 3 wt%. Moreover, PPS could achieve a sustained release effect on polyphenols with a relatively low release rate (63.83 %) even after seven days' time elapsed. Finally, the PA-PPE film displayed superior performance in reducing the weight loss and browning index of fresh-cut apples within 24 h of storage. The development of PA-PPE film could promote sustainable resource protection and demonstrate promising prospects in the field of fresh-cut fruit packaging.

Enhancing oxygen permeability and water content in silicone hydrogels through carboxylic acid and surfactant incorporation

BackgroundSilicone hydrogels are vital materials in fields like contact lenses, biomedicine, and electronic devices, prized for their unique properties including oxygen permeability and equilibrium water content (EWC). These features make them ideal for applications that require both breathability and moisture retention, enhancing their performance and comfort in various uses. Typically, enhancing the silicone content increases oxygen permeability but reduces EWC, creating a significant trade-off. MethodsThis study introduces an innovative approach using carboxylic acid and surfactant to address this challenge. The addition of carboxylic acid markedly boosts the EWC by increasing both freezable free water and bound water. Simultaneously, the surfactant enhances the connectivity within the silicone structure, mitigating the reduction in oxygen permeability and improving the material's ductility, which is often compromised by water absorption that restricts the motion of the silicone chains. Significant findingsWith these modifications, the silicone hydrogel achieves approximately 97 % transmittance at 550 nm, with oxygen permeability reaching 100.4 barrer and EWC at 58.4 %, representing improvements of 11.3 % and 61.3 %, respectively, compared to the original material. These results exceed many of the enhancements in silicone hydrogels previously reported in the literature.

Enhanced water and oxygen barrier properties of deacetylated konjac glucomannan/high acyl gellan gum water gradient film for improved frozen fish fillet preservation

The use of konjac glucomannan (KGM)/high acyl gellan gum (HAGG) edible film with single-sided unsaturated water swelling, designated as a water gradient film (WGF), has been shown to effectively enhance the preservation quality of frozen fish fillets. This study investigates the potential of using partially deacetylated konjac glucomannan (DKGM)/HAGG WGFs to enhance the preservation of frozen fish fillets. The partial deacetylation of KGM improved the water vapour and oxygen barrier properties of the frozen KGM/HAGG WGF, which exhibited a combination of film and ice structural characteristics. This improvement is attributed to strengthened interactions between DKGM and HAGG, resulting in a more structured film matrix that exhibited reduced permeability to both water vapour and oxygen. Furthermore, the improved interactions between DKGM and HAGG led to the formation of smaller polysaccharide ice crystals, which in turn increased the oxygen diffusion path along the intercrystalline boundaries, further decreasing oxygen permeability. Over a 90-day freezing period, the DKGM/HAGG WGF significantly outperformed traditional KGM/HAGG WGF, ice glazing, and polyethylene film packaging in preserving the quality of frozen fish fillets. This study provides a promising strategy for the design and development of DKGM-based WGFs for frozen fish fillet preservation applications.

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.

Effects of ethyl maltol on properties of starch-based active packaging: Morphology, volatile release and mold inhibition

Ethyl maltol, known for its caramel-like flavor and antimicrobial properties, blends compatibly with baked goods. In this study, ethyl maltol-incorporated starch films were developed as potential active food packaging materials. Films containing 0–10% ethyl maltol were prepared and characterized for their physicochemical, antimicrobial, and barrier properties. Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy confirmed interactions between ethyl maltol and starch, leading to modified thermal properties and enhanced film smoothness. Dynamic mechanical analysis revealed a shift in the relaxation temperature with increasing ethyl maltol content, indicating changes in polymer chain mobility. Water vapor permeability decreased with ethyl maltol incorporation, likely due to reduced hydrophilicity, while oxygen permeability increased, suggesting increased hydrophobicity. Ethyl maltol exhibited antifungal activity against Aspergillus niger, with a maximum inhibition zone of 1.53 mm at 10% loading. When incorporated into starch films, ethyl maltol effectively inhibited fungal growth in butter cake, extending its shelf life by up to three-fold. The controlled release kinetics of ethyl maltol from the films was analyzed using gas chromatography-mass spectrometry (GC-MS), revealing a linear release profile. These results demonstrate the potential of ethyl maltol-incorporated starch films as active, biodegradable food packaging materials with antimicrobial properties and significant shelf-life extension benefits.