Water Vapor Transmission Rate Research Articles

Hydrogen Role on the Properties of Silicon Nitride for Flexible Thin Film Encapsulation

High transmittance, high density, and good mechanical properties of silicon nitride (SiNx) make it a potential candidate for barrier layers of flexible organic light emission diodes (FOLEDs). However, the overall characteristics and water oxygen barrier properties of the films are easily affected by the dangling bonds in the films. After adding hydrogen flow rate to the deposition conditions of SiNx films, the hydrogen content interacts with the dangling bonds in amorphous SiNx, which could reduce the number of dangling bonds and improve the density of the hydrogenated amorphous silicon nitride (SiNxHy) films. The high‐density film layer could effectively prevent the invasion of water vapor due to its smaller pinhole density. Therefore, the water oxygen barrier performance of SiNxHy is significantly improved, the maximum decrease in water vapor transmittance rate (WVTR) value is approximately 22.4%. In addition, the increase of hydrogen content also changed the overall properties of the films, including transmittance, elastic modulus, hardness, residual stress, and fracture strain. Therefore, compared with SiNx films, SiNxHy films have more excellent mechanical and optical properties. The SiNxHy films featuring a simplified preparation process with high efficiency, low cost, and superior barrier performance is of great potential for the commercial applications.

Optimization of the Thickness, Water Vapour Transmission Rate and Morphology of Protein-Based Films Incorporating Glycerol and Polyethylene Glycol Plasticizers

Edible film is a thin layer that can coat food products and protect them from physical, chemical, and microbiological disturbances. This study aimed to determine the effect of the concentration ratio and different plasticizers on the thickness, water vapour transmission rate, and morphology of protein-based edible films. The study used a completely randomized design with a factorial pattern. The experiment involved two factors: Factor A, which was the whey-gelatine concentration ratio, at three levels (A1 = 1:0.5; A2 = 1:0.75; A3 = 1:1); and Factor B, which was the plasticizer, at two levels (B1 = glycerol; B2 = polyethylene glycol (PEG)). The study revealed that the water vapour transmission rate was significantly affected (P<0.01) by the interaction between whey-gelatin and different types of plasticizers. Additionally, the film thickness was significantly affected (P<0.01) by the whey-gelatine ratio, and the water vapour transmission rate was significantly affected (P<0.01) by the different types of plasticizers used. The film made from protein had a thickness of 0.282-0.357 mm, a water vapour transmission rate of 4.27-5.55 g/mm2.h, and a homogeneous surface structure resulting from the good mixing of whey and gelatin. The concentration of whey-gelatine and the use of different plasticizers can affect the thickness, WVTR, and morphology of the film. The use of glycerol as a plasticizer resulted in a greater thickness, water vapour transmission rate (WVTR), and morphology compared to those of the PEG plasticizer when the whey-gelatin concentration was 1:1.

Packaging Material Use Efficiency of Commercial PET and Glass Bottles for Mineral Water

The influence of the bottle material (glass, PET), the reusability (reusable and disposable bottles), and the carbonization (still, medium, classic mineral water) on the filling ratio, packaging material use efficiency, cost, and shelf life were evaluated. Two hundred different bottles were purchased and characterized regarding their filling volume, the weight of the bottle, the weight of the closure, the weight of the label, and the maximum full-rim volume of the bottle. The packaging material use efficiency was calculated. The shelf life was evaluated by calculating the water vapor and carbon dioxide transmission rates. The ratio of filling volume to the packaging weight of disposable PET bottles was, on average, two times higher compared to returnable PET bottles and 20 times higher compared to glass bottles. Shelf life was, on average, higher than factor two for glass bottles compared to PET bottles. On average, but not in all cases, mineral water packaged in disposable PET bottles was cheaper compared to reusable PET and glass bottles. This paper provides a benchmark for the packaging community, especially when data for life cycle assessment are required, and the different advantages and disadvantages of different bottle materials for mineral water are shown.

Modification of polyvinyl alcohol with 2-hydroxypropionic acid and cross-linking with glutaraldehyde for the preparation of biodegradable mulch paper and its properties

Abstract The preparation of biodegradable mulch film with paper-based materials has become a significant focus in mulch film development due to the serious pollution caused by plastic mulch film. This study utilized the esterification cross-linking reaction of LA, PVA, and GA to coat the surface of paper as the substrate. FTIR, TGA, XRD, SEM, tensile testing, and oxygen, water vapor barrier performance tests were performed. The optimal conditions for film preparation were determined to be a 10 % PVA aqueous solution, 5 % GA content, and a PVA/LA/GA ratio of 1:2:1. The resulting film paper exhibited a dry strength of 6.52 kN/m, a wet strength of 0.23 kN/m, a tearing degree of 969.35 mN, a Cobb value of 12.04 g/m2, a water vapor transmission rate of 573.27 g m−2 24 h−1, and an oxygen transmission rate of 7.373 cm3 m−2 24 h−1. After a 6-week landfill degradation test, the film showed a degradation rate of 25.3 %, while still maintaining a tensile strength of 1.89 kN/m. Field application tests in greenhouses confirmed that the film paper facilitated the growth of strawberry, its mechanical and barrier properties suitable for a biodegradable paper mulch.

Antibacterial and wound healing performance of a novel electrospun nanofibers based on polymethyl-methacrylate/gelatin impregnated with different content of propolis

Wound management and care mainly relies on the production of new and effective wound dressing materials. Chronic wounds require protection against pathogens and bacterial infection. Therefore, it is very important to design wound dressings with antibacterial and restorative capabilities. In this research, polymethyl-methacrylate (PMMA) and gelatin (Gel) nanofibers (NFs) were produced in different ratios by electrospinning method. Propolis (Pro) as a wound healing drug was added to the optimal PMMA70/Gel30 parent scaffold at different concentrations (10, 30 and 50 %w/v). Physical and chemical characterization, porosity, degradation, water vapor transmission rate (WVTR), swelling, mechanical properties and contact angle of the mats were analyzed. The NFs presented a homogeneous and defect-free morphology. The PMMA70/Gel30 mats showed the lowest average diameter (362.1 ± 132.3 nm) among the scaffolds. In addition, the highest wettability (∼70°) and WVTR (∼250 g/m2 × 24h) are related to PMMA70/Gel30. The addition of Pro extract (up to 50%) increased the mean diameter of NF (571.1 ± 171.8 nm). None of the scaffolds showed toxicity in the environment. The optimal PMMA/Gel/Pro50% NF showed more adhesion and higher cell viability than other samples. The antioxidant activity of PMMA/Gel/Pro50% is more about 10 times compared to PMMA70/Gel30. Pro extract showed significant antibacterial activity in the scaffolds, so that the release of Pro (∼70% in 24hrs) in the PMMA/Gel/Pro50% caused the inhibition of S. aureus (9 mm) and E. coli (11 mm) bacteria in Mueller's culture medium. All these findings confirm that the produced NF mats, especially those loaded with Pro, have a high potential to be used as an effective wound dressing.

Citric acid crosslinked carboxymethyl cellulose edible films: A case study on preserving freshness in bananas

The study involves the preparation and characterization of crosslinked-carboxymethyl cellulose (CMC) films using varying amounts of citric acid (CA) within the range 5 %–20 %, w/w, relative to the dry weight of CMC. Through techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, carbonyl content analysis, and gel fraction measurements, the successful crosslinking between CMC and CA is confirmed. The investigation includes an analysis of chemical structure, physical and optical characteristics, swelling behavior, water vapor transmission rate, moisture content, and surface morphologies. The water resistance of the cross-linked CMC films exhibited a significant improvement when compared to the non-crosslinked CMC film. The findings indicated that films crosslinked with 10 % CA demonstrated favorable properties for application as edible coatings. These transparent films, ideal for packaging, prove effective in preserving the quality and sensory attributes of fresh bananas, including color retention, minimized weight loss, slowed ripening through inhibiting amyloplast degradation, and enhanced firmness during storage.

Bioinspired fabrication of transparent poly(vinyl alcohol)-based films with excellent strength, ultraviolet blocking performance, and water vapor barrier properties

The development of biodegradable plastics with advanced mechanical performance and multifunctionality using renewable materials is highly important for their industrial applications. In this work, a novel eco-friendly and high-performance film was constructed by incorporating lignin–Cu nanoparticles (LNP@Cu) to poly(vinyl alcohol) (PVA) to mimic the granular nanostructure in mussel byssus cuticle. LNP@Cu with abundant o-quinone and o-phenol groups was prepared by the reduction of Cu(NO3)2 using alkaline lignin. The nanoparticles were found to have a spherical morphology with a diameter of approximately 500 nm and the LNP@Cu formed dense hydrogen bonds with the PVA matrix. The mechanical properties of the bioinspired films were dramatically improved and far superior to previously reported PVA films and the majority of engineering plastics. With 5 wt% of LNP@Cu loading, the films showed the optimal tensile strength of 106.9 MPa and toughness of 76.6 MJ m−3, which are 2.27 and 4.04 times as high as those of the neat PVA film, respectively. In addition, the fabricated PVA films exhibited excellent ultraviolet (UV)-shielding property and high transparency. Compared with the pristine PVA film, reinforced films showed decreased hydrophilicity and water vapor transmission rates. Overall, these excellent properties make the fabricated films a great potential for applications in packaging and UV shielding fields, giving inspirations for the design of robust green polymeric materials that meet industrial requirements.

Smart carrageenan/carboxymethyl cellulose films combined with zein/gellan gum microcapsules encapsulated by composite anthocyanins for chilled beef freshness monitoring

The demand for smart packaging to monitor food spoilage is increasing. In the present study, composite anthocyanin microcapsules (CAM) were prepared by using zein and gellan gum as wall materials and protecting composite anthocyanin (CA). Carrageenan (Car)/sodium carboxymethylcellulose (CMC)-based indicator films (CC) containing CAM microcapsules were developed for monitoring the freshness of beef. The results demonstrated that the composite anthocyanins could be well dispersed in the CC matrix. CAM significantly reduced the effects of light and temperature on the stability of anthocyanins. CAM significantly improved the thermal stability, barrier properties and tensile strength of the films. The infrared spectra showed that the components of the indicator films were structurally similar and well-compatible. Among them, the indicator film CC/CAM-3 had the highest tensile strength (17.76 MPa), the lowest water vapor transmission rate (1.35 × 10−11 g/m·s·Pa) and a tight and neat cross-section. The color of the indicator film changed significantly in the ammonia environment: pink→blue-green→yellow. Applying different concentrations of indicator films to beef freshness monitoring, we found that beef reached sub-freshness and spoilage on days 4 and 7, respectively, and accordingly the indicator film CC/CAM-3 changed from pink to purple and green. To examine its capability as a colorimetric indicator film, we related the change in beef quality to the ΔE value of the indicator film, which proved to be the most sensitive when used to monitor the freshness grade of beef, as demonstrated by the indicator film CC/CAM-3.

Structure and functional properties of aluminum hydroxide reinforced bamboo‐derived cellulose acetate composite film for biodegradable packaging

AbstractBiodegradable plastics are gaining popularity as environmentally friendly functional materials. This study focuses on the preparation of aluminum hydroxide (Al(OH)3) reinforced cellulose acetate composite films using a cost‐effective approach. The process involves synthesizing bamboo‐derived cellulose acetate (BDCA), dissolving it in tetrahydrofuran with glycerol as a plasticizer, and incorporating Al(OH)3 particles into the casting solution to reinforce the cellulose acetate film. Analyses on microstructure and characteristics of the films were conducted through various techniques, including scanning electron microscopy (SEM), Fourier transform infrared (FT‐IR) spectroscopy, x‐ray diffraction (XRD), water contact angle measurement, and tensile testing. The results indicate that the Al(OH)3 particles were well‐dispersed in the composite films, leading to a strong interaction with the cellulose acetate matrix. As a result, the prepared composite films exhibited significantly higher tensile strength compared to pure bamboo‐derived cellulose film. Additionally, they demonstrated improved anti‐ultraviolet properties and a lower water vapor transmission rate, despite being more hydrophilic. This method holds significant potential for commercial applications in producing high‐performance cellulose acetate‐based composite films.Highlights Bamboo‐derived cellulose acetate was synthesized through chemical processes. BDCA based composite film reinforced with Al(OH)3 was prepared by casting method. The Al(OH)3 significantly enhance the functional properties of the composite film. Composite films showed good performances for packaging according to the results.

Physicochemical and repellent properties of chitosan films loaded with essential oils for producing an active packaging effective against the food pest Sitophilus oryzae

Sitophilus oryzae (L.) (Coleoptera: Dryophtoridae) represents one of the most important pests of stored products. The adults are considered very effective packaging penetrators, causing serious economic losses. Hence, the development of new food packaging technologies is crucial to prevent its infestations. In this study, Citrus × aurantium L., Elettaria cardamomum (L.) Maton, Ocimum basilicum L., and Piper nigrum L. essential oils (EOs) were analyzed by GC-EIMS and then used to produce aromatized chitosan (CHT)-based films. The spontaneous volatile emissions of these films were evaluated by headspace solid phase micro-extraction (HS-SPME) to assess the chemical composition of the vapors released from the CHT matrix after 2, 5, 7, 9, 12, and 14 days. The thickness, moisture content, swelling properties, total soluble matter, water vapor transmission rate, color, and transmission and transparency of light of all the CHT films after 1, 7, 14, 21, 28, and 35 days were also assessed. Furthermore, the repellency of the EO-loaded CHT films was tested daily against S. oryzae adults for 28 days.Overall, adding the different EOs to the CHT films had a good impact on their physical and chemical properties. In particular, the C. × aurantium EO-loaded CHT film was characterized by the lowest swelling ratio, solubility, and water vapor transmission rate, besides having the lowest impact on the film transparency and opacity among the four EOs involved and a pleasant, lemon-like odor. The same C. × aurantium EO-loaded film was also the most effective as a repellent against S. oryzae, with a long-lasting effect for up to 28 days on the pest and a median repellency time (RT50) of 7.184 days.

Pengembangan smart edible film packaging berbahan konjac dengan ekstrak bunga rosella dan cangkang telur ayam sebagai bahan aktif

Edible film is a thin sheet plastic-like biodegradable film that can be used for food packaging material. Edible film can be developed into smart edible film packaging by combining it with smart packaging principles by adding active ingredients. This research aimed to determine the effect of different concentrations of rosella flower extract and chicken eggshell powder on the physicochemical characteristics of smart edible film and its capability to act as smart packaging in a model system. The research design used was a Randomized Block Design with two factors, namely three levels of rosella flower extract concentration and three levels of eggshell powder concentration, all with three replications. The concentration of rosella flower extract used as a treatment in this study was 0 (without rosella flower extract) as a control, 1:15 (w/v of water as solvent), and 1:30 (w/v), while the concentration of eggshell powder used as a treatment in this study was 0 (without eggshell powder) as control; 0.15% (w/v); and 0.30% (w/v). The results showed that the higher the extract concentration added to the formulation, the more the total phenols, anthocyanins, and antioxidant activity would increase. In contrast, the difference in eggshell concentration did not have a significant effect. The tensile strength will increase as the eggshell concentration increases, while the percent elongation will decrease. The water vapor transmission rate (WVTR) decreased with increasing eggshell concentration. There is an increase in color intensity in smart edible packaging used to store steamed chicken meat. Meanwhile, smart edible packaging can prevent damage to steamed chicken meat in terms of color, aroma, and taste.

Film dressings from Thai mango seed kernel extracts versus nanocrystalline silver dressings in antibacterial properties.

Introduction: The extract from the Mango Seed Kernel (MSK) has been documented to exhibit antibacterial activity against Gram-positive and Gram-negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa. This suggests that biomaterials containing MSK extract could be a viable alternative to conventional wound treatments, such as nanocrystalline silver dressings. Despite this potential, there is a notable gap in the literature regarding comparing the antibacterial effectiveness of MSK film dressings with nanocrystalline silver dressings. This study aimed to develop film dressings containing MSK extract and evaluate their antibacterial properties compared to nanocrystalline silver dressings. Additionally, the study aimed to assess other vital physical properties of these dressings critical for effective wound care. Materials and methods: We prepared MSK film dressings from two cultivars of mango from Thailand, 'Chokanan' and 'Namdokmai'. The inhibition-zone method was employed to determine the antibacterial property. The morphology and chemical characterization of the prepared MSK film dressings were examined with scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR), respectively. The absorption of pseudo-wound exudate and water vapor transmission rate (WVTR) of film dressings were evaluated. Results: The results showed that 40% of MSKC film dressing had the highest inhibition zone (20.00 ± 0.00mm against S. aureus and 17.00 ± 1.00mm against P. aeruginosa) and 20%, 30%, and 40% of MSKC and MSKN film dressings had inhibition zones similar to nanocrystalline silver dressing for both S. aureus and P. aeruginosa (p > 0.05). In addition, all concentrations of the MSK film dressings had low absorption capacity, and Chokanan MSK (MSKC) film dressings had a higher WVTR than Namdokmai MSK (MSKN) film dressings. Conclusion: 20%, 30%, and 40% of MSK film dressing is nearly as effective as nanocrystalline silver dressing. Therefore, it has the potential to be an alternative antibacterial dressing and is suitable for wounds with low exudate levels.

Preparation, Characterization, and Evaluation of Enzyme Co-Modified Fish Gelatin-Based Antibacterial Derivatives.

Fish gelatin (FG)-based wound dressings exhibit superior water absorption capacity, thermal stability, and gelation properties, which enhance the performance of these dressings. In this study, our objective was to investigate the conditions underlying the enzymatic hydrolysis of FG and subsequent cross-linking to prepare high-performance gels. A two-step enzymatic method of protease-catalyzed hydrolysis followed by glutamine transglutaminase (TGase)-catalyzed cross-linking was used to prepare novel high-performance fish gelatin derivatives with more stable dispersion characteristics than those of natural gelatin derivatives. Compared with conventional TGase cross-linked derivatives, the novel derivatives were characterized by an average pore size of 150 μm and increased water solubility (423.06% to 915.55%), water retention (by 3.6-fold to 43.89%), thermal stability (from 313 °C to 323 °C), and water vapor transmission rate, which reached 486.72 g·m-2·24 h-1. In addition, loading glucose oxidase onto the fish gelatin derivatives increased their antibacterial efficacy to >99% against Escherichia coli and Staphylococcus aureus.

Functionalization of wool fabric by rice stubble extract dyeing and bio-mordanting

In this research, rice stubble, an air-polluting agricultural waste after burning the current years, was considered to explore a sustainable application in rice-growing countries. The rice stubble extract was used to dye and functionalize the wool fabric. The dyed woollen fabrics were thoroughly characterized concerning their physical, chemical and comfort properties by scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, water vapor transmission rate (WVTR), and ultraviolet protection factor (UPF). The color characteristics, color fastness against the woollen fabrics, and flame retardancy were also assessed. The results revealed that the rice stubble extract has a coloring chromophore to offer bright shades with considerable fastness abilities. The rice stubble-dyed woollen fabrics showed considerable water vapor permeability, efficient UV shielding, and adequate flame Retardancy. The dyed woollen fabrics showed a maximum water vapor permeability of 2500 g/m2/24h, ultraviolet shielding of 350, and a limiting oxygen index of 30.

Encapsulation of flexible organic solar cells via parylene and alumina dyads

Robust encapsulation is indispensable for flexible organic solar cells (OSCs) moving into practical applications because the materials and interfaces of the cells are susceptible to water vapor and oxygen under illumination. Fleixble barrier films are one of the key parts of the encapsulation. In this work, we report the fabrication of flexible barrier films comprising of alternating parylene C and alumina dyads, and the application of these barrier films to encapsulate flexible OSCs. Parylene C layers are deposited by chemical vapor deposition (CVD) and dense alumina layers are grown by atomic layer deposition (ALD). The fabricated film comprising of three dyads of parylene C and alumina shows a low water vapor transmission rate (WVTR) of 8.7 × 10−4 g m−2 day−1 (25 °C, 100% RH) devrived by calcium conductance test. Encapsulated OSCs could retain 80% of their initial efficiency after immersed into water for 624 h, and could retain 81% of their initial efficiency under continuous illumination for 1156 h in ambient atmosphere.

Determination of Biogenic Amine Level Variations upon Storage, in Chicken Breast Coated with Edible Protective Film.

A new chitosan-based protective film containing rosemarinic acid (0.282% w/w) has been elaborated. The film was formed from a water-oil emulsion system and applied to poultry meat samples using a dip-coating technique. Various physicochemical parameters of the coatings, such as thickness, Young's modulus, elongation at break, water vapor transmission rates, and antioxidant activity, were tested with free-standing film samples peeled from a Petri dish. Compared to neat chitosan films obtained similarly, new films cast from the emulsion showed significantly better elasticity (Young's modulus was diminished from 1458 MPa to about 29 MPa). Additionally, barrier properties for moisture transition decreased from 7.3 to 5.8 g mm m-2 day-1 kPa-1. The coated poultry samples were subsequently evaluated in juxtaposition with uncoated ones in a storage test. Levels of selected biogenic amines (histamine, tyramine, tryptamine, phenylethylamine, putrescine, cadaverine, spermine, and spermidine), total bacterial count, and lipid oxidation levels in the meat samples were analyzed during storage at 4 °C (up to 96 h). The results obtained for the biogenic amines, total bacterial content, calculated biogenic amine index, and the ratio of spermidine to spermine in meat samples suggest the advantage of the proposed coatings with rosmarinic acid in protecting poultry meat against environmental factors and rapid spoilage.

Thermostable, water-repellent, moisture-permeable Nomex nanofibrous membranes with a connected PTFE network for personal protective fabrics

Water-repellent and moisture-permeable membranes are highly desirable for improving wearing comfort and protection; however, constructing thermostable fabrics with excellent moisture permeability and high resistance to water penetration in high-temperature personal protection remains a great challenge. Therefore, we fabricate Nomex nanofibrous membranes via electrospinning, and further perform dip-coating with polytetrafluoroethylene (PTFE) emulsion and hot-pressing for constructing connected PTFE network. The Nomex membranes possess hydrophobic PTFE networks and retain porous structures, improving their water repellent without influencing water vapor transmission. Furthermore, the membranes demonstrate prominent thermostability due to the synergistic effect of the high-temperature-resistant Nomex substrate and PTFE hydrophobic agent. Consequently, the Nomex/PTFE membranes exhibit prominent water-repellent and moisture-permeability with high hydrostatic pressure of 58 kPa and satisfactory water vapor transmission rate of 6008 g m−2 d−1, as well as remarkable thermostability to maintain structural stability under 300 °C, suggesting great promise as exceptional candidates for high-temperature personal protection and comfort management.

Effects of different biopolymers and additives on mechanical and barrier properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) blend films

Bio-based materials could offer solutions to the problems of petroleum-derived material usage and waste management. By taking into consideration this fact, the aim of this study was to create alternative product recipes for flexible packaging with the use of biodegradable polymers in line with sustainable packaging targets. In this study, the exit point was to prepare polybutylene adipate terephthalate (PBAT) and polyhydroxyalkanoate (PHA)-based bioblends with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by solution casting method in order to create biocomposite combination for flexible packaging with improved properties. Hydroxypropyl methylcellulose (HPMC) additive was used to enhance barrier properties. Thermal, mechanical, optical properties, oxygen permeability, water vapor transmission rate, and morphological features of the resultant biocomposites were characterized. First of all, it was seen that the elongation at break and tensile strength properties of single biopolymers can be combined in binary structures. Then, by establishing triple blend structures, biocomposite films with improved properties were obtained. In addition, the effects of alternative polybutylene succinate (PBS) and polylactic acid (PLA) biopolymers to PBAT biopolymer in triple bioblends were examined. As a result of the studies it was found that the PHBV/PBAT/PHA structure could be developed with functional additives in order to reach the best flexible packaging formula. It was found that the oxygene transmission rate (OTR) value was improved compared to PE with PHA, PHBV and HPMC additives, decreased to 29 cc/m2.day with PBS and 14 cc/m2.day with PLA added to the structure.

Preparation and Characterization of Pullulan-Based Packaging Paper for Fruit Preservation.

Improving the shelf lives of fruits is challenging. The biodegradable polysaccharide pullulan exhibits excellent film-forming ability, gas barrier performance, and natural decomposability, making it an optimal material for fruit preservation. To overcome problems of high cost and film porosity of existing packaging technologies, we aimed to develop pullulan-based packaging paper to enhance the shelf lives of fruits. A thin paper coating comprising a mixture of 15 wt.% pullulan solution at various standard viscosities (75.6, 77.8, and 108.5 mPa·s) with tea polyphenols (15:2) and/or vitamin C (150:1) improved the oxygen transmission rate (120-160 cm3 m-2·24 h·0.1 MPa), water vapor transmission rate (<5.44 g·mm-1 m-2·h·kPa), maximum free radical clearance rate (>87%), and antibacterial properties of base packaging paper. Grapes wrapped with these pullulan-based papers exhibited less weight loss (>4.41%) and improved hardness (>16.4%) after 10 days of storage compared to those of control grapes (wrapped in untreated/base paper). Grapes wrapped with pullulan-based paper had >12.6 wt.% total soluble solids, >1.5 mg/g soluble protein, >0.44 wt.% titratable acidity, and ≥4.5 mg 100 g-1 ascorbic acid. Thus, pullulan-based paper may prolong the shelf life of grapes with operational convenience, offering immense value for fruit preservation.

Evaluating a promising methylcellulose hydrogel for enhanced diabetic foot ulcer therapy through comprehensive preclinical studies

The present research focuses on formulating and evaluating hydrogels modified with crosslinking agents using methylcellulose to treat diabetic foot ulcers (DFU). Methylcellulose hydrogels are prepared and characterized for their crosslinking capacity through FTIR and degradation studies. The optimized hydrogel is further assessed for viscosity, gel strength, contact angle, in-vitro biodegradation, water-vapor transmission rate, anti-bacterial activity, and in-vivo efficacy. The results demonstrate that the developed hydrogel exhibits promising properties for DFU treatment, including increased wound healing percentage, improved ulcer morphology, reduced levels of proinflammatory cytokines, and enhanced tissue characteristics. These findings suggest that the novel hydrogel composition could serve as a viable alternative to existing dressings for DFU management.