Water Vapor Transmission Rate Research Articles

Sorption Isotherm and Effect of Packaging Materials on Proximate, Organoleptic and Lipid Oxidation Quality of Chicken Nuggets Stored at Two Different Temperatures

The study Investigated sorption isotherm features and the effects of packaging materials of both high-density and low-density polyethylene on sensory properties, proximate composition and lipid oxidation of chicken nuggets in storage. Boneless chicken breast was procured from a reputable source and cut into sizeable weight of 50g each to produce the chicken nuggets used for the studies. The experimental setup for sorption isotherm analysis in this study involved using a gravimetric method to equilibrate the product at various relative humidity levels. Five (5g) grams of oven-dried chicken nugget samples of known moisture content were placed in a controlled humidity chamber, and the weight changes of the samples were monitored until equilibrium was reached. GAB equation was used to evaluate the product ware activity and monolayer moisture. Sensory assessment was evaluated using a 9- point hedonic scale while proximate composition of the chicken nuggets samples was determined according to the methods of the Association of Official Analytical Chemists. Thiobarbituric acid reactive substances (TBARS) assay was used to measure malondialdehyde (MDA) levels as a marker of lipid oxidation. The investigation showed that sensory qualities, proximate composition and lipid oxidation of chicken nuggets were markedly affected by the variance in temperature settings, with distinct disparities seen among different materials for packaging. Chicken nuggets stored at 25 0C caused a significant loss in organoleptic properties and some nutritional composition such as protein and fat. Storage of chicken nugget at 25 0C and 40 C showed a varied values in malondialdehyde as content ranged from 0.52 to 0.81 for chicken nugget stored at 250 C and 0.17 to 0.43 for the product stored at 40 C across the packaging materials investigated. The water activity and monolayer moisture results of sorption analysis revealed that good packaging materials of very low water vapour transmission rate should be used for storage of chicken nuggets as high-density polyethylene offered a promising alternative than low density polyethylene.

Antifungal activity of alginate coatings with essential oil of Mexican oregano incorporated in the stem of tomatoes

SummaryAdding natural antimicrobials such as essential oils (EOs) to alginate coatings on fruits provides an antifungal effect and a semipermeable water vapour barrier. This work aims to evaluate the antifungal effect of Lippia berlandieri S. (Mexican oregano) EO incorporated into alginate to coat tomato stems inoculated with Penicillium commune, Fusarium spp., or Cladosporium herbarum. Alginate films and coatings with EO concentrations (0%, 0.25%, 0.75%, 1%, 2%, or 4% v/v) were prepared to evaluate their properties (physical, mechanical, and water vapour transmission rates) as well as their effect on mould growth on tomato stems for 28 days during refrigerated storage. Mould growth was described with probabilistic and time‐to‐growth predictive models. Two treatment types were assessed (tomato inoculated and coated, TIC, and tomato coated and inoculated, TCI) to provide information about the moment of mould contamination (before or after coating). EO concentration influenced the alginate films' physical, mechanical, and barrier properties. Testing the coatings against moulds revealed varying inhibitory effects. Fusarium spp. exhibited the highest resistance, while C. herbarum was the most susceptible. The predictive models appropriately described the probability of growth or the time‐to‐growth of the studied moulds, identifying critical concentrations of oregano EO needed to inhibit mould growth effectively. The findings suggest that alginate coatings with oregano EO can serve as a natural and effective antifungal treatment for tomatoes, offering insights into optimal concentrations and application methods for extended shelf life.

Simple Encapsulation Method for Flexible Perovskite Solar Cells with Transparent Electrode‐Integrated Barrier Films

Flexible perovskite solar cells (PSCs) have been rapidly developed for realistic applications such as windows and auxiliary power supplies of electronics. However, the moisture penetration through the flexible substrate films still poses a major obstacle because it can destroy the perovskite films under outdoor conditions. Unlike conventional PSCs with glass‐based encapsulation, flexible PSCs face challenges in finding suitable materials and structures that maintain flexibility while providing effective encapsulation. Simple encapsulation methods for flexible PSCs are proposed using a transparent electrode‐integrated flexible barrier (TIFB) substrate comprising silicon nitride (SiNx)/polyethylene terephthalate (PET)/indium tin oxide (ITO). A dense SiNx layer with chemical vapor deposition on ITO–PET films is deposited and a more flexible TIFB than the conventional laminated substrate owing to its thinness is achieved. TIFB shows a low water vapor transmission rate of 4.3 × 10−3 g m−2 day. Consequently, the efficiency of TIFB‐based PSCs under harsh conditions (60 °C and 90RH%) exhibits an acceptable decrease within 10% of its highest efficiency after 400 h, which is the most stable data under high temperature and humidity among existing flexible encapsulated PSCs. TIFB, as a flexible substrate, is a major candidate to protect flexible electronics and PSCs against external factors.

Evaluating bag storage technologies for physical characteristics, loss reduction and economic viability in pulses

Meticulous selection of storage bags is vital to optimize grain preservation, mitigate losses, and improve rural income. A comprehensive comparative evaluation of four different commercial pulse storage bag technologies (Jute bag, Woven polypropylene bag (WPP), Purdue Improved crop storage bag (PICS), and Grainpro bag) was conducted alongside novel polypropylene reinforced Jute storage bag (PPRJ). The storage bags were examined for their physical properties (unit weight, coefficient of friction, breaking strength), water vapour transmission rate (WVTR), and effectiveness in preserving pulse (Bengal gram (Cicer arietinum, Var. Swetha ICCV -2)) quality and quantity during storage. Unit weight was highest for jute bags (0.14 ± 0.080 g/cm2), which reduced by 35.9 % after reinforcement with polypropylene, and lowest for Grainpro bags (0.03 ± 0.002 g/cm2). Jute bag exhibited the highest breaking strength (181.0 ± 1.06 kgf), which decreased by 23.7 % after reinforcement. Synthetic fiber bags had lower breaking strength and coefficient of friction, limiting their stacking ability. WVTR of the jute bag reduced by 39.2 % after reinforcement. The PICS bag offered the highest protection to stored Bengal gram. Weight loss was more than 25% and 10% of the initial grain weight in Jute and WPP, respectively, due to inefficient barrier properties, whereas the PPRJ bag was similarly effective as hermetic bags. The benefit-cost ratio ranged between 0.219 and 0.297 for the three profit-yielding bags (PICS, Grainpro, and PPRJ). Polypropylene-reinforced jute bags represent a promising advancement in sustainable grain storage practices. The significance of establishing hermetic conditions to suppress insect populations and safeguard grain quality was reaffirmed in the study.

PEG-crosslinked O-carboxymethyl chitosan films with degradability and antibacterial activity for food packaging

This study developed a kind of PEG-crosslinked O-carboxymethyl chitosan (O-CMC–PEG) with various PEG content for food packaging. The crosslinking agent of isocyanate-terminated PEG was firstly synthesized by a simple condensation reaction between PEG and excess diisocyanate, then the crosslink between O-carboxymethyl chitosan (O-CMC) and crosslinking agent occurred under mild conditions to produce O-CMC–PEG with a crosslinked structure linked by urea bonds. FT-IR and 1H NMR techniques were utilized to confirm the chemical structures of the crosslinking agent and O-CMC–PEGs. Extensive research was conducted to investigate the impact of the PEG content (or crosslinking degree) on the physicochemical characteristics of the casted O-CMC–PEG films. The results illuminated that crosslinking and components compatibility could improve their tensile features and water vapor barrier performance, while high PEG content played the inverse effects due to the microphase separation between PEG and O-CMC segments. The in vitro degradation rate and water sensitivity primarily depended on the crosslinking degree in comparison with the PEG content. Furthermore, caused by the remaining –NH2 groups of O-CMC, the films demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus. When the PEG content was 6% (medium crosslinking degree), the prepared O-CMC–PEG−6% film possessed optimal tensile features, high water resistance, appropriate degradation rate, low water vapor transmission rate and fine broad-spectrum antibacterial capacity, manifesting a great potential for application in food packaging to extend the shelf life.

Preparation and Characterization of Amoxicillin-Loaded Polyvinyl Alcohol/Sodium Alginate Nanofibrous Mat: Drug Release Properties, Antibacterial Activity, and Cytotoxicity

AbstractThis study aimed to prepare a polyvinyl alcohol/sodium alginate (PVSA) nanofibrous mat as an amoxicillin (AMOX) delivery system. AMOX was loaded to the PVSA nanofibers during electrospinning, and the AMOX-loaded PVSA (PVSA/AMOX) nanofibrous mat was cross-linked by glutaraldehyde (GA). The PVSA/AMOX nanofibrous mat was characterized by Fourier Transform infrared spectroscopy, scanning electron microscopy, Brunauer–Emmett–Teller, and mercury porosimetry analyses. The thickness, air permeability, and water vapor transmission rate of the PVSA/AMOX nanofibrous mat were 0.43 ± 0.08 mm, 17.2 ± 4.91 L/m2/s, and 1485 ± 13.6 g/m2/d, respectively, which were suitable for wound dressing applications. The tensile strength was 6.73 ± 0.48 MPa and elongation at a maximum load was 81.9 ± 17.0%, within the ranges of human skin’s values. The total porosity was 59.4%, enabling cell adhesion, migration, and proliferation. The PVSA/AMOX nanofibrous mat has high swelling (319 ± 4.2%) and low degradation (2.2 ± 0.1% in 10 days) ratios. The nanofibrous mat cross-linked with 0.25% GA solution for 20 min had a 73.07% cumulative release for 90 min. The drug release kinetics were obeyed to the Korsmeyer-Peppas model. The nanofibrous mat presented antibacterial activity on S. aureus ATCC 29213 and E. coli ATCC 25922, and there was no cytotoxic effect on the human normal keratinocyte cells, demonstrating the potential for use in wound dressing applications.

Enriched oil-in-water emulsions as bioactive agents for locust bean gum films: A comparative investigation

In this study, pracaxi oil (PO) and olive oil (OO) emulsions, enriched with turmeric powder (Cur) and stabilized by nanofribrillated cellulose (NFC), were developed and incorporated to glycerol-plasticized locust bean gum (LBG) dispersions. Films were obtained by solution casting, and their properties were compared, aiming to expand PO application as a potential constituent of active food packaging. The films were characterized for their morphological, structural, transparency, gas permeability, wettability, thermal, mechanical, and antioxidant properties. In relation with the plasticized LBG film, both emulsion films showed improved humidity content, surface wettability, oxygen barrier capacity, thermal stability, and mechanical properties. As for wettability, while the initial water contact angle for the LBG film was θ0 = 93.4°, values of θ0 = 105.5° and θ0 = 99.2° were determined for the LBG films incorporated with PO- and OO-based emulsions, respectively. In comparison with the LBG film, the incorporation of PO-based droplets led to an approximately 8.0% reduction in the water vapor transmission rate values. Also, in comparison with the LBG film, the LBG/NFC/PO-Cur and LBG/NFC/OO-Cur films were capable of reducing the peroxidation value of sunflower oil by 16% and 11%, respectively. Enhancements in tensile strength values of 44% and 49% were determined for the PO- and OO-based emulsion films. The emulsion films presented similar antioxidant properties and better preservation of strawberry model food than LBG and polyethylene films. The results of the comparative experiments suggested that the use of PO may be expanded as a component of active food packaging.

Fabrication of chitosan-based smart film by the O/W emulsion containing curcumin for monitoring pork freshness

In this research, curcumin (Cur) was encapsulated in succinylated soy protein isolate (SSPI) emulsion and combined with chitosan (CS) to prepare a smart film. The good adsorption ability of SSPI at the oil-water interface provides good physical stability for preparing Cur-loaded emulsion. These CS smart films containing SSPI emulsions with different curcumin content were evaluated on the structure, mechanical, barrier, antioxidant, antibacterial properties, and controlled release behavior. SEM and FT-IR results showed that the Cur-loaded emulsion was compatible with the CS matrix. By adding the emulsion, the film blocked 97.11% of ultraviolet radiation, reduced the water vapor transmission rate by 42%, and improved the swelling degree (32.26%), water solubility (12%), thermal stability and elongation at break (70.79 %) (p < 0.05). In addition, the film has a high antibacterial effect on Staphylococcus aureus and Escherichia coli (Bacterial inhibition zone diameter: 19.59 mm and 18.66 mm) and the release rate of curcumin in the film reaches 82.60%, mainly following the Fickian diffusion. The film gradually turns red under alkaline conditions, a property that makes the films successful in monitoring the deterioration of pork during storage. Adding SSPI emulsions and curcumin to films has great potential for food freshness monitoring and packaging.

Synergistic effects of nucleating agent, chain extender and nanocrystalline cellulose on PLA and PHB blend films: Evaluation of morphological, mechanical and functional attributes

The current study focuses on reactive extrusion of poly (lactic acid) (PLA) and polyhydroxybutyrate (PHB) based blend films using epoxide styrene–acrylic (ESA) chain extender, pentaerythritol (PEOL) as a nucleating agent and cellulose nanocrystal (CNC). The blown films were subjected to various mechanical, thermal, barrier, and microstructural analyses to determine their suitability for packaging. Test results indicated that the incorporation of 0.5 wt% of chain extender significantly improved the elastic modulus and yield strength of PLA/PHB blend films. Further addition of 1 wt% of PEOL improved the crystallinity as well as mechanical strength in the films. FTIR analysis suggested chain conformations in different crystalline regions of PLA/PHB blend films whereas nucleation density and arrangement in crystal growth have been analysed by POM and SEM micro graphical studies. Additionally, the presence of CNCs within the PLA/PHB blend films showed an improved water vapour transmission rate (WVTR) of 90.53 g/m2.day revealing the creation of a tortuous path. Evaluation of optimum glossiness and haze of the films were done and the co-efficient of friction analysis depicted more anti-slip properties of the films.

Physicochemical and biological characterization of propolis-loaded composite polyamide-6/soybean protein nanofibers for wound healing applications

Dressings are pivotal in aiding wound recovery, yet they are burdened by significant constraints. In addition to possessing antibacterial properties, the effectiveness of a wound dressing must be rigorously assessed for its potential utility across diverse medical applications. Propolis (Pro) is widely acknowledged for its antioxidant, antibacterial, and anti-inflammatory properties, positioning it as a promising candidate for wound healing and tissue engineering applications. This study presents a novel composite nanofiber (NF) material comprising polyamide-6 (PA6) and soybean protein as matrix components, incorporating Pro as a payload. We aimed to mimic the extracellular matrix, thus promotion the proliferation and adhesion of mouse embryonic fibroblast cells (NIH3T3) on the scaffold's surface. The morphology and composition of the NFs, examined through scanning electron microscopy (SEM) imaging and Fourier-transform infrared (FTIR) spectroscopy. The Pro-loaded fibers exhibited diameters ranging from 102 to 270 nm. Notably, the NFs demonstrated a dose-dependent increase in porosity, water vapor transmission rate, and fluid uptake capacity. However, the hydrophilic categorized nanofibers (NFs) did not exhibit a concentration-dependent effect on contact angle measurements. After a 15-day period, the Pro-loaded fibers experienced degradation within the range of 39–53 %. Using UV–visible spectrophotometry, the amount of pro released was measured. The rates of release were found to be 29.93 %, 41.02 %, and 60.06 % within 24 h for PA6/Soy/Pro5 %, PA6/Soy/Pro10 %, and PA6/Soy/Pro20 % NFs, respectively. Importantly, our study showcased the significant inhibitory effects of Pro-loaded fibers on the growth of E. coli and S. aureus, with inhibition increasing proportionally with higher Pro concentrations. This observation underscores the potential of Pro-based composite NFs as effective antimicrobial agents for wound dressings and tissue scaffolds. Furthermore, the biocompatibility of the fabricated nanofibrous mats was confirmed through the MTT test, affirming the non-toxic nature of all formulations. SEM imaging further demonstrated the optimal adhesion of cells on the NFs, confirming the findings of the MTT test and highlighting the suitability of Pro-loaded NFs for cell attachment and proliferation.

Eco-Friendly Poly (Butylene Adipate-co-Terephthalate) Coated Bi-Layered Films: An Approach to Enhance Mechanical and Barrier Properties.

In this research work, a coated paper was prepared with poly (butylene adipate-co-terephthalate) (PBAT) film to explore its use in eco-friendly food packaging. The paper was coated with PBAT film for packaging using hot pressing, a production method currently employed in the packaging industry. The coated papers were evaluated for their structural, mechanical, thermal, and barrier properties. The structural morphology and chemical analysis of the coated paper confirmed the consistent formation of PBAT bi-layered on paper surfaces. Surface coating with PBAT film increased the water resistance of the paper samples, as demonstrated by tests of barrier characteristics, including the water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and water contact angle (WCA) of water drops. The transmission rate of the clean paper was 2010.40 cc m-2 per 24 h for OTR and 110.24 g m-2 per 24 h for WVTR. If the PBAT-film was coated, the value decreased to 91.79 g m-2 per 24 h and 992.86 cc m-2 per 24 h. The hydrophobic nature of PBAT, confirmed by WCA measurements, contributed to the enhanced water resistance of PBAT-coated paper. This result presents an improved PBAT-coated paper material, eliminating the need for adhesives and allowing for the fabrication of bi-layered packaging.

Enrichment of creatine-gelatin cryogel with Zataria multiflora essential oil and titanium dioxide nanoparticles as a potential wound dressing

The prevalence of microbial infections in wounds, particularly burn wounds, presents a significant medical concern due to the inherent vulnerability of compromised skin to pathogen colonization and invasion. This study focused on the synthesis and evaluation of a creatine-gelatin cryogel, enriched with Zataria multiflora essential oil and titanium dioxide nanoparticles for potential wound dressing applications. The chemical and physical characteristics of the formulation were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and mechanical tests. Further studies such as wound fluid absorptivity, water vapor transmission rate, solubility, moisture content, porosity, and release properties were investigated. The release test demonstrated an encapsulation efficiency of 98.8 % and a loading capacity of 16.45 %, signifying a suitable cryogel matrix. The disk diffusion assay demonstrated that the synthesized cryogel had excellent antimicrobial efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida species. Additionally, the cryogel exhibited great cytocompatibility and hemocompatibility (∼100 %). Our findings suggest that the creatine-gelatin cryogel blend enriched with Zataria multiflora essential oil and titanium dioxide nanoparticles possesses structural integrity, a cell-friendly nature, moisture-retaining capabilities, and biocompatible characteristics. These properties collectively render it an exceptionally suitable material for advanced wound dressings. Moreover, the demonstrated functional properties of the cryogel, including its ability to prevent infection, exhibit antioxidant activity, and retain moisture, underscore its potential for effective burn wound management.

Green Electrospun Poly(vinyl alcohol)/Gelatin-Based Nanofibrous Membrane by Incorporating 45S5 Bioglass Nanoparticles and Urea for Wound Dressing Applications: Characterization and In Vitro and In Vivo Evaluations.

This study reports the fabrication and characterization of poly(vinyl alcohol) (PVA) and gelatin (Gel)-based nanofiber membranes cross-linked with citric acid (CA) by a green electrospinning method in which nano 45S5 bioglass (BG) and urea were incorporated. Various combinations of PVA, gelatin, and BG were prepared, and nanofiber membranes with average fiber diameters between 238 and 595 nm were fabricated. Morphological, chemical, and mechanical properties, porosity, swelling, water retention, and water vapor transmission rate of the fabricated membranes were evaluated. PVA:Gel (90:10), 15% CA, and 3% BG were determined as the optimum blend for nanofiber membrane fabrication via electrospinning. The membrane obtained using this blend was further functionalized with 10% w/w polymer urea coating by the electrospray method following the cross-linking. In vitro biocompatibility tests revealed that the fabricated membranes were all biocompatible except for the one that functionalized with urea. In vivo macroscopic and histopathological analysis results of PVA/Gel/BG and PVA/Gel/BG/Urea treated wounds indicated increased collagenization and vascularization and had an anti-inflammatory effect. Furthermore, careful examination of the in vivo macroscopic results of the PVA/Gel/BG/Urea membrane indicated its potential to decrease uneven scar formation. In conclusion, developed PVA/Gel/BG and PVA/Gel/BG/Urea electrospun membranes with multifunctional and biomimetic features may have the potential to be used as beneficial wound dressings.

Fluorine Free Surface Modification of Microfibrillated Cellulose-Clay Composite Films: Effect of Hydrophobicity on Gas Barrier Performance

Diffusion barrier composite films based on microfibrillated cellulose (MFC) and clay were developed with attention paid to the influence of thermal annealing and a fluorine-free surface silylation on their microstructure, water contact angle (WCA), mechanical properties, oxygen transmission rate (OTR), and water vapor transmission rate (WVTR). The OTR of MFC at 23 °C increased from 1.2 to 25.3 cm3/m2/day/bar as relative humidity increased from 50% to 80%. Annealing increased the film’s crystallinity, surface roughness, and hydrophobicity, while decreasing its OTR by 20% at 80%RH. The addition of clay led to a 30% decrease of OTR at 80%RH due to partial exfoliation and to a 50% decrease when combined with annealing. Silylation increased the hydrophobicity of surface of the film and its combination with clay and annealing led to a WCA of 146.5°. The combination of clay, annealing, and silylation considerably reduced the OTR at 80%RH to a value of 8 cm3/m2/day/bar, and the WVTR at 23 °C and 50%RH from 49 g/m2/day for MFC to 22 g/m2/day. The reduction of OTR and WVTR was found to correlate with the increase in surface hydrophobicity of the film, which was attributed to the reduced access of water molecules within the MFC network.

The synergistic effect of body modification and surface coating for the moisture barrier of hydrophilic PU film

Polyurethane (PU) films have established a distinctive position among various protective materials due to their outstanding chemical and physical properties. However, their limited moisture barrier performance hinders their broader applications. To solve this difficult problem, PU film is first modified by adding reactive fillers (MgO) and physical barrier fillers (Modified graphene oxide, M-GO), and then Si-DLC coating is deposited on the surface of the film by hollow cathode plasma immersion ion implantation (HCPIII) method at near room temperature. MgO can react with the water molecules diffused into the film, while the addition of M-GO extends the diffusion path of water molecules. It is revealed that the addition of 5% MgO and 0.5% M-GO, along with the deposition of a 2.56 μm Si-doped DLC coating, leads to a remarkable 14.67-fold reduction in the water vapor transmittance rate (WVTR). The result of molecular dynamics simulations shows that the reactive sheet filler captures the water molecules and reduces the WVTR. In addition, the combination method of PU body modification and surface coating is suitable for polyurethane foam (PUF) to reduce the WVTR as a double coating. It’s amazing that the WVTR of PUF significantly reduces by 15.29 times after double-coating. The combination of body modification and surface coating provides an effective route for significantly improving the moisture barrier property of hydrophilic polymer film and polymer foam.

Scalable fabrication of multifunctional polylactic acid fibrous membranes with enhanced superhydrophobicity and radiative cooling performance

The disadvantages of traditional bio-based materials melt centrifugal spinning, such as low efficiency, long cycle and poor performance, limit its industrialization process. Herein, a scalable strategy was proposed for the fast and scale fabrication of bio-based melt centrifugal spinning fiber. The polymer melt was continuously transported to the high-speed rotating centrifugal disk, where it was rapidly conveyed and separated. The separated melt was then drawn and cooled by the synergistic supergravity and high-pressure cyclone field, resulting in formatting a nonwoven fabric by self-bonding alone with a diameter of ∼3 μm. Compared to conventional white CVC fabrics, the fabricated polylactic acid fibrous membranes demonstrated exceptional biocompatibility (cell viability of 98.7%), radiative cooling properties and favorable emissivity (94.1%), which can reduce the covered object temperature by 4.6 °C during hot summer. Furthermore, the water vapor transmission rate, moisture regain, water absorption, and boiling water shrinkage rate of PP20/8-F are 39.98 g m-2 h-1, 2.31%, 2.09%, and 8.11%, respectively, meeting the comfort requirements of wearable fabrics. The robust superhydrophobicity with a water contact angle of 153±1° provides excellent antifouling and self-cleaning properties. This novel bio-based material melt centrifugal spinning method provides a viable strategy for the industrial preparation of high-performance and functionalized fibrous.

Effects of montmorillonite on the loading and release of Piper betle L. extract applied for wound dressing based on chitosan/polyvinyl alcohol

In this study, we investigate the influence of montmorillonite (MMT) on the loading and release of Piper betle L. extract (PLE)–a medicinal herb containing active secondary metabolites with antibacterial, antioxidant, and anti–inflammatory effects. MMT (1 %, 3 %, 5 %) was blended into the chitosan/polyvinyl alcohol (CS/PVA) biocomposite film by the solution evaporation method, and then PLE was loaded onto this biocomposite using the immersion method. The tensile strength and the ability to absorb exudates of the CS/PVA film improved with the increase in MMT content. The MMT 3 % film was considered to have the best properties: good mechanical properties with a tensile strength of 27.44 ± 0.27 MPa and elongation at break of 14.57 ± 0.30 %, potential for wound dressing due to its ability to absorb wound exudate (swelling degree 61.70 ± 0.30 %) and a suitable water vapor transmission rate (1999 ± 47 g/m2·d). The presence of MMT (1 %, 3 %, 5 %) in the CS/PVA film led to an increase in the PLE loading efficiency of the films compared to the film without MMT, up to 1.65, 1.73, and 1.87 times, respectively. The MMT 3 % and 5 % films also exhibited a sustained PLE release effect for up to 24 h. MMT increased PLE bioavailability through bioactivity tests: antibacterial activity against both E. coli and S. aureus, antioxidant activity, effective healing of 2nd–degree burn wounds, and biocompatibility with the L929 fibroblasts cell line. The combination of physicochemical properties and biological activities proved that the MMT/PLE drug delivery system based on the CS/PVA biocomposite is promising for wound dressing.

Maleic acid crosslinked starch/polyvinyl alcohol blend films with improved barrier properties for packaging applications

Incorporating starch, which is a potential biodegradable substitute for petroleum-based polymers, into conventional polymers is challenging owing to limitations in processability and weak-performing resulting materials. Herein, corn starch/polyvinyl alcohol (PVA) blend films (starch: PVA ratio of 50:50) were prepared via the solvent casting method using glycerol as a plasticizer and with varying concentrations of maleic acid as the crosslinking agent. Fourier transform infrared spectroscopy revealed the molecular interactions of the maleic acid crosslinker with the polymeric network of starch and PVA through an ester linkage. The properties of the films were strongly dependent on the maleic acid concentration. An increasing maleic acid concentration imparted hydrophobicity to the film; therefore, water swelling was significantly reduced, and water resistance was enhanced. The film containing 20 wt% maleic acid exhibited excellent barrier properties, with the lowest oxygen and water vapor transmission rates of 0.5 ± 0.2 cc/m2⋅day and 232.3 ± 5.4 g/m2⋅day, respectively. Moreover, the mechanical properties of the film improved with increasing crosslinking. This study demonstrates that the addition of maleic acid leads to an improvement in the overall performance of starch/PVA blend films. Therefore, maleic acid-crosslinked films can be used as barrier materials in food packaging applications.

Karakteristik Arang Kulit Buah Kakao dan Arang Batang Bambu Terhadap Mutu Briket

The purpose of this research is to determine the optimum properties of biodegradable plastic made from banana weevil starch with the addition of straw cellulose as reinforcement. This research was conducted using Completely Randomized Method (CRD) with four treatments and four replications. In this study were the addition of straw cellulose with a ratio of starch and cellulose 1:0; 1:0,5 ; 1:1 and 1:1,5. Tests were carried out on strong tensile strength, elongation at break, biodegradation, swelling and water vapor transmission rate. The data obtained were analyzed statistically using analysis of variance (ANOVA). The addition of straw cellulose had a significant effect on the manufacture of biodegradable plastics. The result were biodegradable plastic increase tensile strength, decreases elongation at break, increase biodegradation and air resistance, reduces the rate of water vapor transmission. Biodegradable plastic with the best treatment is the ratio of starch starch ratio of 1 : 1.5 cellulose. The best result biodegrabable plastic has for tensile strength value of 9.56 MPa, elongation 6.8%, complete biodegradation on day 6, swelling 41.51% and WVTR 0.0156%.

Comparison of the Film Properties of Lemon and Sour Cherry Seed Essential Oil-Added Glycerol and/or Sorbitol-Plasticized Corn, Potato, Rice, Tapioca, and Wheat Starch-Based Edible Films

In this study, lemon, and sour cherry seed essential oil-added glycerol and/or sorbitol-plasticized corn, potato, rice, tapioca, and wheat starch-based edible films were produced using the casting method. Starch, essential oil type and glycerol and/or sorbitol effects on the thickness, moisture content, water solubility, swelling index, and water vapor transmission rate of the films have been studied. The interaction of the film components was evaluated by Fourier transform infrared spectroscopy. It was seen that wheat starch-based control films give the lowest thickness value (0.010 mm). Wheat starch-based control films (15.50%), sour cherry seed essential oil-added corn starch (17.80%), and lemon essential oil-added rice starch-based composite films (17.70%) have high moisture content. The lowest solubility values were obtained from wheat starch control (22%) and sour cherry seed essential oil-added corn starch composite (16.40%) films. The highest swelling index values were obtained from wheat starch-based control (210.90-289.0%), sour cherry seed essential oil-added tapioca starch (388.80%), and lemon essential oil-added potato starch-based (433.20%) composite films. Rice starch-based control films have the lowest water vapor transmission rate (3.30×10−8−5.70×10−8). FTIR spectra of edible composite films proved that there is no chemical interaction between the film component and that they kept their structure. The main difference of this study from previous studies was the use of sour cherry seed essential oil for the first time in edible film production and the comparison of the film properties of corn, potato, rice, tapioca, and wheat starch-based edible films plasticized with glycerol or sorbitol.