Film production with flaxseed mucilage and polyvinyl alcohol mixtures and evaluation of their properties

Potential use of extracted flax seed mucilage in the construction of macroporous cryo-scaffolds

Mucilage is a natural source of polysaccharides that has recently attracted attention for use in biomaterial production. It attracts attention with its easy and fast extraction, biocompatibility, high water retention capacity, and biodegradability. Although there are studies on the characterization of mucilage obtained from different plant sources, the interaction of this polymer with other polymers and its potential to form new biomaterials have not yet been sufficiently investigated. Based on this, in this study, the potential of mucilage extracted from flaxseed for the production of cryogels for tissue engineering applications was demonstrated. Firstly, yield, basic physicochemical properties, morphology, and surface charge-dependent isoelectric point determination studies were carried out for the characterization of the extracted mucilage. The successful preparation of mucilage was evaluated for the construction of cryo-scaffolds and 3D, spongy, and porous structures were obtained in the presence of chitosan and polyvinyl alcohol polymers. A heterogeneous morphology with interconnected macro and micro porosity in the range of approximately 85-115 m pore diameter was exhibited. Due to the high hydrophilic structure of the mucilage, which is attached to the structure with weak hydrogen bonds, the contact angle values of the scaffolds were obtained below 80° and they showed the ability to absorb 1000 times their dry weight in approximately 30 min. As a preliminary optimization study for the evaluation of mucilage in cryogel formation, this work introduced a new construct to be developed as wound dressing scaffold for deep and chronic wounds.

Postbiotics-enriched flaxseed mucilage coating: A solution to improving postharvest quality and shelf life of strawberry

This research aimed to assess the effects of flaxseed mucilage (Mu) coatings supplemented with postbiotics (P) obtained from Lactobacillus acidophilus LA-5 on various physical, biochemical, and microbial characteristics of strawberry fruits. Strawberry fruits were immersed for 2 min in Mu2.5 (2.5 % mucilage in distilled water), Mu5 (5 % mucilage in distilled water), P-Mu2.5 (2.5 % mucilage in undiluted postbiotics) and P-Mu5 (5 % mucilage in undiluted postbiotics) solutions and were stored at 4 °C and 85 RH for 12 days. All coatings were effective in reducing fungal count compared to the uncoated control fruits. Mu5 coating exhibited the highest efficacy, reducing fungal count by 2.85 log10 CFU/g, followed by Mu2.5 (1.47 log10 CFU/g reduction) and P-Mu2.5 groups (0.90 log10 CFU/g reduction). The fruits coated with edible coatings showed significant delays in the change of weight loss, pH, and total soluble solids as compared to the uncoated fruits. The coating containing postbiotics i.e., P-Mu5 also showed a significant increase in the total phenolic contents, total flavonoid content, antioxidant capacity, and total anthocyanin content at the end of storage relative to the uncoated fruits. Thus, Mu and P-Mu coatings may be a useful approach to maintaining the postharvest quality of strawberry fruits during cold storage.

Linden-based mucilage biodegradable films: A green perspective on functional and sustainable food packaging

This study focuses on the utilization of linden mucilage, extracted from the linden tree, as a potential natural polymer source for the production of composite films. The films, which incorporating linden water extract, essential oil, and oil, exhibited improved thermal stability, surface morphology, and water resistance. Biodegradability assessments, particularly for films using essential oil and oil, showed promising outcomes by maintaining structural integrity. Antimicrobial assays demonstrated significant resistance against pathogens, indicating potential applications requiring microbial resistance. Mechanical analyses revealed a trade-off between tensile strength and elongation at break with addition of components. Composite films exhibited reduced water vapor permeability which correlate with water solubility and contact angle measurements. Soil biodegradation studies highlighted the films' potential to mitigate environmental impact. Cytotoxicity tests confirmed the safety of these films for potential food applications. Additionally, antioxidant assays showed increased radical scavenging activity in films with added components. In conclusion, linden-based composite films exhibit promising characteristics, suggesting their potential as sustainable and functional materials, particularly for use in food packaging.

Furoic acid-mediated konjac glucomannan/flaxseed gum based green biodegradable antibacterial film for Shine-Muscat grape preservation

Considering the growing threats to the environment and human health, such as plastic pollution and food spoilage, the development of naturally antibacterial food packaging materials with biodegradable capabilities has recently attracted considerable attention. This work applies the concept of green environmental protection to packaging technology, and a new type of green edible antibacterial packaging film was developed. The basic idea is to incorporate furoic acid (FA), which possesses excellent antibacterial activity, into the flaxseed gum and konjac glucomannan matrix (FK) as a filler to obtain a series of FK-FA bioactive films. This incorporation simultaneously improves the hydrophobicity and UV-barrier ability by 12.28 % and 42.87 %, respectively. Meanwhile, the diameters of the antibacterial zone of the FK-FA0.4% films (composite FK films containing 0.4 % FA) against E. coli and S. aureus increased to 38.98 mm and 36.29 mm from 24.00 mm of pure FK film, respectively. As a consequence, the grape sample sealed with FK-FA0.4% film remained edible on the 18th day of storage, while those packaged with commercial PE film and pure FK were seriously rotted and lost edible value on the 12th day, further confirming the enhanced preservation capacity. Finally, the as-prepared films were established to be biodegradable and were almost completely degraded within 25 days under simulated environmental conditions. Overall, these promising results show the potential of FK-FA films for replacing plastic packaging materials as eco-friendly edible films with prolonged shelf life for active packaging.

Biodegradable composite films based on mucilage from Opuntia ficus-indica (Cactaceae): Microstructural, functional and thermal properties

This study evaluated the feasibility of using cactus mucilage (CM) to elaborate biobased composite films blended with styrene-butadiene rubber latex (SBL). The CM was extracted and precipitated with ethanol (CMET) and isopropanol (CMIS). Mucilage-based films were formulated using three levels of mucilage (4, 6, and 8 wt%). The microstructure, thickness, moisture content, density, water contact angle, water vapor permeability, film solubility, thermal stability, and toughness of mucilage films blended with SBL (SBL/CMET and SBL/CMIS) were measured. The properties of mucilage-based films varied systematically, depending on the concentration of mucilage. The addition of SBL to CM film produces compatible, hydrophobic, flexible, and stiffer films with low moisture contents and good barrier properties. The mucilage film incorporated with 6 wt% CMET and CMIS reached the highest Young's modulus of 1512 ± 21 and 1988 ± 55 MPa, respectively. The DSC of produced films reveals that the Tg of SBL/CMIS is lower than that of SBL/CMIS. The synthesized films were structurally stable at high temperatures. The biodegradability of the composite films buried in the ground shows that the produced films are 100 % biodegradable after 40 days. Thus, CM blended with SBL can benefit specific applications, especially food packaging.

UV-blocking biodegradable film based on flaxseed mucilage/pectin impregnated with titanium dioxide and calcium chloride for food packaging applications

A UV blocking and potentially biodegradable composite films are fabricated from flax seed mucilage and pectin with different concentrations of titanium dioxide (TiO₂) and crosslinked with calcium chloride (CaCl₂). This study aimed to evaluate the physical, surface, and optical properties including color, potential biodegradability, and absorption kinetics of the developed film. From the observations made, addition of 5 wt% TiO₂ enhanced UV barrier property with a total color change (ΔE) of 23.441 ± 0.54 and increased its crystallinity to 54.1 % from 43.6 %. Crosslinking agent and TiO₂ resulted in a prolonged period of biodegradation of >21 days when compared to neat film. Also, swelling index of crosslinked film was reduced by 3 times of non-crosslinked films. Surface of the developed films has no cracks and agglomerates as observed from scanning electron microscope. Moisture absorption kinetic study reveals that all the films have best-fit data following a pseudo-second-order kinetic model with a correlation coefficient ≥0.99 and the rate was controlled by inter-particle diffusion. The film with 1 wt% TiO₂ and 5 wt% CaCl₂ showed the lowest rate constants (k₁) of 0.27 and (k₂) of 0.029. The results suggest that this film can be potentially used in food packaging as a UV-blocking layer with potential biodegradability and good moisture resistance as compared to pure flax seed mucilage or pectin films.

Ixiolirion tataricum mucilage/chitosan based antioxidant films activated by free and nanoliposomal fennel essential oil

Ixiolirion tataricum mucilage (ITM) was characterized and applied in fabrication of ITM/chitosan (CH) blend films activated by Foeniculum vulgare essential oil (FEO) in free and nanoliposomal forms. Uniform smooth surface structure, viscoelastic solid-like behavior and Newtonian nature of ITM were confirmed by morphological and rheological analyses. The prepared FEO nanoliposomes (FEO-NLPs) showed desirable properties in terms of particle size (57.2 nm), polydispersity index (0.243), zeta-potential (-17.6 mV), and encapsulation efficiency (85.2 %). The enhancing effects of FEO-NLPs and the adverse effects of free FEO on the crystalline, morphological and structural properties of films were confirmed by XRD, FE-SEM and ATR-FTIR tests. FEO-NLPs loaded films had better mechanical, thermal, water and gas barrier and antioxidant properties than neat film. Analysis also indicated the high controlled release of FEO from the films containing the nanoliposomal form of FEO. The films containing free FEO showed higher antibacterial activity against E. coli and S. aureus in comparison with FEO-NLPs loaded ones. The results showed the potential of FEO-NLPs loaded ITM/CH films for antioxidant food packaging applications.

Wound healing promotion by flaxseed extract-loaded polyvinyl alcohol/chitosan nanofibrous scaffolds

Impaired wound healing is a severe complication of sufferers, related to prolonged wound closure, a high infection rate, and eventually disabilities of organs. To aid resolve this issue, we developed the electrospun polyvinyl alcohol and chitosan (PVA/CS) nanofibrous scaffold-loaded flaxseed extract. The scaffold containing 10 wt% of the extract indicated a three-dimensional cross-network with a nano-scale diameter (257 ± 37 nm) and smooth surface. Also, the relevant analyses confirmed high water absorption, porosity, and wettability of the scaffold. Fourier-transform infrared (FTIR), degradation, and mechanical studies revealed the intact presence and loading of the extract into the scaffold, the complete degradation over 48 h, and a high tensile elastic modulus. Besides, the advanced scaffold displayed remarkable anti-oxidant and could inhibit the growth of both Gram-positive and negative bacteria compared to the free PVA/CS scaffold. Desired fibroblast viability and blood compatibility of flaxseed-loaded scaffold endorsed the biocompatibility for wound zones. The in vitro studies showed that the flaxseed-loaded scaffold resulted in an accelerated wound healing process and 100 % closure of the scratched area within 48 h. The results obtained reveal that the flaxseed-loaded PVA/CS electrospun scaffold could be effectively applied for wound healing promotion.

Flaxseed mucilage/calcium phosphate composites as bioactive material for bone tissue regeneration

Biocompatible polymers are attractive material for the manufacturing of surgical implants which break down in vivo without the necessity for a consequent operation for removal. Elaboration of composite biomaterials scaffolds as artificial bone graft materials remains a major task in bioengineering. Flaxseed mucilage was used as bioactive polysaccharide for preparing composite scaffolds made of calcium phosphate embedded in mucilage matrix. Calcium chloride was mixed with mucilage followed by the addition of phosphate precursor to stimulate the in situ formation of calcium phosphate. The obtained scaffolds mucilage/calcium phosphate at different pHs (5 and 8) were characterized using FTIR, XRD, TGA, SEM/EDX and TEM. The results showed the formation of two phases: mucilage/dicalcium phosphate dihydrate (MU/brushite) and mucilage/hydroxyapatite (MU/HA). MTT test was applied to evaluate viability of MC3T3-E1 osteoblasts cells, and the formed hybrids at various pH conditions were classified as non-cytotoxic. These findings establish the potential of developed composite to be used as bone graft substitute materials.

Eco-friendly flaxseed mucilage biofilms fabricated by gamma irradiation

With looming the global energy crisis and environmental problems Biodegradable green blends based on natural resources and biodegradable polymers have increasingly attracted many researches interest due to their advantages of low cost, use of renewable resource, and biodegradability. In this study, flaxseed mucilage (FM) was extracted with distilled water and utilised to make films with varying ratios of polyvinyl alcohol (PVA) and chitosan (Cs). Gamma irradiation was used as green method to improve the performance of the produced films. Then the films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–vis spectrophotometry and XRD analysis. The tensile measurements, moisture content were used to evaluate the films’ qualities. When flaxseed mucilage is mixed with PVA/Cs blend, it forms films that are less resistive, less rigid, and more flexible, improves mechanical properties and thermal stability. Films containing mucilage and PVA/Cs blend exhibited a compact and homogeneous structure under SEM, confirming the FTIR spectra that suggested a chemical interaction between these three biopolymers. Based on all above properties of the developed films, it can be envisaged to use these films for packaging applications.

Designing Deferoxamine-Loaded Flaxseed Gum and Carrageenan-Based Controlled Release Biocomposite Hydrogel Films for Wound Healing

In this study, biocomposite hydrogel films made from flaxseed gum (FSG)/kappa carrageenan (CGN) were fabricated, using potassium chloride as a crosslinker and glycerol as a plasticizer. The composite films were loaded with deferoxamine (DFX), an iron chelator that promotes neovascularization and angiogenesis for the healing of wounds. The properties of the biocomposite hydrogel films, including swelling, solubility, water vapor transmission rate, tensile strength, elongation at break, and Young’s modulus studies, were tested. The films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). In addition, drug release studies in PBS at pH 7.2 were investigated. In vivo analysis was performed by assessing the wound contraction in a full-thickness excisional wound rat model. Hematoxylin & eosin (H & E) and Masson’s trichome staining were performed to evaluate the effect of the films on wound healing progress. The visual and micro-morphological analysis revealed the homogenous structure of the films; however, the elongation at break property decreased within the crosslinked film but increased for the drug-loaded film. The FTIR analysis confirmed the crosslinking due to potassium chloride. A superior resistance towards thermal degradation was confirmed by TGA for the crosslinked and drug-loaded films. Drug release from the optimum film was sustained for up to 24 h. In vivo testing demonstrated 100% wound contraction for the drug-loaded film group compared to 72% for the pure drug solution group. In light of the obtained results, the higher potential of the optimized biocomposite hydrogel film for wound healing applications was corroborated.

A Review of Extraction Techniques and Food Applications of Flaxseed Mucilage

Flaxseed contains significant concentration of mucilage or gum (a type of hydrocolloid). Flaxseed mucilage (FM) predominantly occurs in the outermost layer of the seed’s hull and is known to possess numerous health benefits such as delayed gastric emptying, reduced serum cholesterol, and improved glycemic control. FM is typically composed of an arabinoxylan (neutral in nature) and a pectic-like material (acidic in nature). Similar to gum arabic, FM exhibits good water-binding capacity and rheological properties (similar functionality); therefore, FM can be used as its replacement in foods. In this review, an overview of methods used for FM extraction and factors influencing the extraction yield were discussed initially. Thereafter, food applications of FM as gelling agent/gel-strengthening agent, structure-forming agent, stabilizing agent, fat replacer, anti-retrogradation agent, prebiotic, encapsulating agent, edible coatings and films/food packaging material, and emulsifier/emulsion stabilizer were included. At the end, some limitations to its wide application and potential solutions were added.

Design of polysaccharidicAloe veragel incorporated PVA/tetracycline electrospun cell culture scaffolds for biomedical applications

In this study, hybrid nanofibrous 3D scaffolds containingAloe vera(AV), polyvinyl alcohol (PVA) and tetracycline hydrochloride (TCH) are fabricated by electrospinning for cell culture applications. The role of polysaccharides present in AV gel is found to enhance the biocompatibility of the nanofibrous scaffolds. Different combinations of the polymers were selected to produce homogenous nanofibers with favorable mean fiber diameter and tensile strength. The surface morphology of the products was studied by SEM and it is found that the mean fiber diameter is decreased to about 188 nm upon addition of the AV component. The electrospun scaffolds were investigated by FT-IR spectroscopy to reveal the chemical structure of the samples and their crystallinity was studied by XRD. The hydrophilicity of the scaffolds was tested by optical contact angle measurements and their mechanical strength was examined by tensile strength tests. It is found that PVA is the main component contributing the mechanical stability of the scaffold structure. The fabricated scaffolds presented a more pronounced inhibitory effect against Gram-positive bacterial strains ofS. aureusandB. cereus. Cell culture experiments using fibroblast L929 murine cells reveals that the AV/PVA/TCH scaffolds are promising for cell growth and the cells are capable of achieving a proper cell adhesion and proliferation. The cell viability experiment by MTT assay exhibits the contributing role of AV gel to L929 cell viability on the AV/PVA/TCH scaffolds.

Preparation of three-layer flaxseed gum/chitosan/flaxseed gum composite coatings with sustained-release properties and their excellent protective effect on myofibril protein of rainbow trout

Plant essential oils lose their activity due to unstable chemical properties and volatility, and the coating can improve their stability by encapsulating. The three-layer coatings were prepared by tape casting method with flaxseed gum (FG) and chitosan (CS) as film-forming materials, eugenol (EG) and laurel essential oil (LEO) as preservatives. The composite coatings were characterized, and their physicochemical properties, release properties, antibacterial and antioxidant properties were determined. Meanwhile, the protective effect of the composite coatings on rainbow trout fillets myofibril protein was studied. The mechanical properties of the FG/CS/FG coatings are better than FG coating. The release of EG and LEO from the coatings are followed simple diffusion mechanism. After added essential oils, the antibacterial and antioxidant properties of the composite coatings are significantly enhanced. In the preservation process of the rainbow trout fillets, the composite coatings can reduce the carbonyl content, increase the sulfhydryl content and Ca²⁺-ATPase activity. The β-sheet content is 6.09%-15.63% higher than that of control, indicating the coatings are helpful to maintain the order of myofibril protein. The composite coatings slowed down the decrease of antioxidant enzyme activity, thus delay the protein oxidation. Because of long-term antibacterial and antioxidant properties, the composite coatings have potential value in food preservation or food packaging materials.

The Renaissance of Plant Mucilage in Health Promotion and Industrial Applications: A Review

Plant mucilage is a renewable and cost-effective source of plant-based compounds that are biologically active, biodegradable, biocompatible, nontoxic, and environmentally friendly. Until recently, plant mucilage has been of interest mostly for technological purposes. This review examined both its traditional uses and potential modern applications in a new generation of health-promoting foods, as well as in cosmetics and biomaterials. We explored the nutritional, phytochemical, and pharmacological richness of plant mucilage, with a particular focus on its biological activity. We also highlighted areas where more research is needed in order to understand the full commercial potential of plant mucilage.