Sodium Alginate Films Research Articles

Bio-composite Films Based on Alginate and Rice Husk Tar Microparticles Loaded with Eugenol for Active Packaging

This work focused on the valorization of tar derived from rice husk pyrolysis as a precursor of matrices for the encapsulation of active principles. In this regard, the development of novel films based on alginate and eugenol-loaded tar microparticles with suitable mechanical properties and antibacterial activity was studied. Tar microparticles loaded with eugenol were incorporated into sodium alginate films and the effect on the mechanical, thermal and humidity resistance properties were determined, as well as the antimicrobial activity. Films with different crosslinking degrees were also prepared using CaCl2, and the eugenol controlled release profiles were evaluated. Crosslinked films exhibited improved mechanical and humidity resistance properties, as well as a lower release rate of eugenol in water. The antimicrobial studies showed that eugenol-loaded films present a higher antimicrobial activity against Staphylococcus aureus. Alginate/eugenol-loaded tar microparticles composites showed an enhancement of antibacterial properties and suitable physical characteristics to be used in active packaging applications.

Coating Fe3O4 quantum dots with sodium alginate showing enhanced catalysis for capillary array-based rapid analysis of H2O2 in milk

A simple and high-throughput colorimetric analysis array has been constructed for quantifying H2O2 in milk using Fe3O4 quantum dots (QDs), which were coated with sodium alginate (SA) and chromogenic substrate onto the arrayed capillary tubes. It was discovered that the Fe3O4 QDs could present larger peroxidase-like catalysis than Fe3O4 nanoparticles (NPs). Particularly, dramatically enhanced catalysis activity could be achieved for Fe3O4 QDs if coated with SA films. Moreover, the use of SA could protect Fe3O4 QDs to expect the improved environmental stability. A capillary arrays-based high-throughput colorimetric platform was thereby developed for the detection of H2O2 in milk, with levels linearly ranging from 10 to 400 μM. Importantly, the developed colorimetric platform with the capillarity power for automatic fetching of multiple samples may promise the practical applications for extensive monitoring of multiple H2O2 samples for food safety.

Effect of gamma irradiation on the physicochemical properties of sodium alginate solution and internally crosslinked film made thereof

Research on using natural origin polymers as substitutes for petroleum-based plastics has been around for years owning to their renewable and sustainable characteristics. The use of ionizing radiation such as gamma (γ) rays for structural modification of natural polymers could broaden its application while protecting the environment. This study investigated the effect of γ-irradiation on the physicochemical properties of sodium alginate solution (SAS) and sodium alginate film (SAF) made thereof. The SAS was irradiated at 0 (control), 5, 10, 20, and 40 kGy before SAF was synthesized. Thermogravimetric analysis (TGA) revealed that the thermal stability of SAS decreased following the first-order degradation kinetics with every two-fold increment in γ-irradiation dose. Fourier transform infrared spectroscopy (FTIR) showed a decrease in the carbonyl group peak intensity for both SAS and SAF as the γ-irradiation dose increased. The critical dose to cause a significant decrease in the molecular weight of SA was determined to be 5 kGy. The water vapor permeability of SAF made using SAS irradiated up to 10 kGy improved by approximately 17% as compared with the control. Overall, this study contributed fundamental knowledge on sodium alginate chain modification induced by γ-irradiation and proposed that irradiated sodium alginate is a promising starting material for the synthesis of biopolymer film.

Oromucosal Alginate Films with Zein Nanoparticles as a Novel Delivery System for Digoxin.

Digoxin is a hydrophobic drug used for the treatment of heart failure that possesses a narrow therapeutic index, which raises safety concerns for toxicity. This is of utmost relevance in specific populations, such as the elderly. This study aimed to demonstrate the potential of the sodium alginate films as buccal drug delivery system containing zein nanoparticles incorporated with digoxin to reduce the number of doses, facilitating the administration with a quick onset of action. The film was prepared using the solvent casting method, whereas nanoparticles by the nanoprecipitation method. The nanoparticles incorporated with digoxin (0.25 mg/mL) exhibited a mean size of 87.20 ± 0.88 nm, a polydispersity index of 0.23 ± 0.00, and a zeta potential of 21.23 ± 0.07 mV. Digoxin was successfully encapsulated into zein nanoparticles with an encapsulation efficiency of 91% (±0.00). Films with/without glycerol and with different concentrations of ethanol were produced. The sodium alginate (SA) films with 10% ethanol demonstrated good performance for swelling (maximum of 1474%) and mechanical properties, with a mean tensile strength of 0.40 ± 0.04 MPa and an elongation at break of 27.85% (±0.58), compatible with drug delivery application into the buccal mucosa. The current study suggests that SA films with digoxin-loaded zein nanoparticles can be an effective alternative to the dosage forms available on the market for digoxin administration.

Molecular Interactions between Methylene Blue and Sodium Alginate Studied by Molecular Orbital Calculations.

A methylene blue (MB) indicator embedded in sodium alginate (SA) film was previously examined for detecting active oxygen species. In a previous study, spectrometry was used to identify and characterize the MB/SA complex. However, the decolorization mechanism was not fully assessed. In this study, our aim is to conduct computational calculations at the B3LYP/6-31G(d) level to clarify the exact types and positions of the interaction that cause the decolorization in MB. The results demonstrate that MB/SA interacts with carboxylates (-COO(superscript)-(superscript)) of SA and the N, C, and S atoms of MB, confirming previous experimental observations.

3D Cross-linked Ti3C2Tx-Ca-SA films with expanded Ti3C2Tx interlayer spacing as freestanding electrode for all-solid-state flexible pseudocapacitor

Ti3C2Tx, a member of the MXene, has attracted extensive interest because of its high conductivity, unique two-dimensional (2D) structure and intrinsic pseudocapacitance for supercapacitors. Flexible and freestanding Ti3C2Tx films are promising electrodes for functioned supercapacitors used in wearable and portable electronic devices. However, the severe self-restacking of 2D Ti3C2Tx nanosheets restraints their practical application. Herein, freestanding and flexible three-dimensional (3D) cross-linked Ti3C2Tx-Ca-SA (sodium alginate) films with expanded Ti3C2Tx interlayer spacing are reported. The expanded interlayer spacing allows more electrolyte ions to quickly intercalate providing more intercalation pseudocapacitance, while the 3D cross-linked microstructure ensures a continuous conductive network facilitating charges transport. Attributing to the unique structure, the Ti3C2Tx-Ca-SA film delivers an outstanding areal capacitance (633 mF cm−2 at 5 mV s−1). Meanwhile, the assembled all-solid-state pseudocapacitor shows good flexibility and capacity stability under various bending conditions. The device exhibits a high energy density up to 12.6 µWh cm−2 at the power density of 375 µW cm−2 and excellent cycling stability, which are much better than prior reported state-of-the-art supercapacitors. This research exploits a simple method to optimize the structure of MXene as state-of-the-art electrodes for high-performance flexible energy-storage devices.

Synthesis of Sodium Alginate-Silver Nanocomposites Using Plasma Activated Water and Cold Atmospheric Plasma Treatment.

In this study, sodium alginate (SA)-based, eco-friendly nanocomposites films were synthesized for potential food packaging applications using silver nitrate (AgNO3) as the metal precursor, reactive nitrogen and oxygen species (RNOS) created within plasma activated water (PAW), or through cold plasma treatment (CP) as reducing agent and SA as stabilizing agent. The formation of silver nanoparticles (AgNPs) was confirmed via the absorption peaks observed between 440 and 450 nm in UV-vis spectroscopy. The tensile strength (TS) and tensile modulus (TM) of the nanocomposite films were significantly higher than those of the SA films. An increase in the TS was also observed as the AgNP concentration was increased from 1 to 5 mM. The storage modulus (G’) of the nanocomposite solution was higher than that of the SA solution. The synthesis of AgNPs resulted both in a higher solution viscosity and a more marked shear-thinning effect. The synthesized AgNPs showed antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The AgNPs were spherical in shape with an average size of 22 nm.

Characterization of sodium alginate coatings with Meyerozyma caribbica and impact on quality properties of avocado fruit

This study was aimed to evaluate the physical, physicochemical, and thermal properties of sodium alginate (SA) films added with Meyerozyma caribbica (SAY) and their effect on quality properties of avocado after their storage (12 days/25 °C, or 10 days/6 °C and ripened at 25 °C/7 days). SAY films were highly soluble (>87%). During their storage, water vapor permeability decreased (1.93 g/(m.s.Pa) x 10−9) and a slight color change (2.11) was found. The thermal analysis allowed us to infer the protective effect of SA on M. caribbica. The yeast addition improved the puncture force of SA films. Besides, SAY coatings reduced the weight loss in avocados (22.8 and 29.8% at 25 °C and combined storage, respectively), delayed the increment of pH and total soluble solids, and the firmness of the whole fruit and flesh were higher than in uncoated fruits. Moreover, the application of SAY coatings allowed to inhibit the development of grey flesh in avocados under both storage conditions. This research demonstrated that SA coatings with M. caribbica are an alternative to maintain the quality properties of avocados for up to 12 and 17 days depending on storage conditions.

Microwave Enabled Physically Cross Linked Sodium Alginate and Pectin Film and Their Application in Combination with Modified Chitosan-Curcumin Nanoparticles. A Novel Strategy for 2nd Degree Burns Wound Healing in Animals.

This study reports microwave assisted physically cross-linked sodium alginate and pectin film and their testing in combination with modified chitosan-curcumin nanoparticles for skin tissue regeneration following 2nd degree burn wound. Film was formulated by solution casting method and physically cross-linked using microwave irradiation at frequency of 2450 MHz, power 750 Watt for different time intervals for optimization. The optimized formulation was analyzed for various physiochemical attributes. Afterwards, the optimized film and optimized modified chitosan-curcumin nanoparticles were tested in combination for skin regeneration potential following burn wound in vivo and skin samples extracted and tested for different attributes. The results indicated that the optimized film formulation (5 min microwave treatment) physicochemical attributes significantly enhanced addressing the properties required of a wound healing platform. The vibrational analysis indicated that the optimized film experienced significant rigidification of hydrophilic domains while the hydrophobic domains underwent significant fluidization which also resulted in significant increase in the transition temperatures and system enthalpies of both polymer moieties with microwave treatment. The combined film and nanoparticles application significantly increased protein content in the wounds which were evident from higher absorbance ratios of amide-I and amide-II (2.15 ± 0.001), significantly higher melting transition temperature and enthalpy (∆T = 167.2 ± 15.4 °C, ∆H = 510.7 ± 20.1 J/g) and higher tensile strength (14.65 ± 0.8 MPa) with significantly enhanced percent re-epithelization (99.9934 ± 2.56) in comparison to other treatments. The combined application of film and nanoparticles may prove to be a new novel treatment strategy for 2nd degree burn wound healing.

Sodium alginate-based nanocomposite films with strong antioxidant and antibacterial properties enhanced by polyphenol-rich kiwi peel extracts bio-reduced silver nanoparticles

Sodium alginate (SA)-based films with excellent antioxidant and antibacterial activities were prepared, which was modified by polyphenol-rich kiwi peel extracts (PE) bio-reduced silver nanoparticles. In detail, PE was employed as reducing and capping agents to self-assemble silver@PE nanoparticles (Ag@PE NPs), which was further used to modify SA film in its functionality. In addition, the effects of the Ag@PE NPs amount on the physicochemical and biological performances were investigated. Results showed that SA-based films had strong tensile strength, water vapor resistance and good UV barrier properties. The incorporation of Ag@PE NPs drove a color change of SA-based films to redness and yellowness, while still showing good transparencies. Besides, Ag@PE NPs modified SA-based films showed a significant enhancement of antioxidant property, as well as an obvious improvement of antibacterial activity against Staphylococcus aureus and Escherichia coli. Therefore, this study provided a new insight for the reutilization of kiwi peels and a green, cheap and easy approach to prepare multifunctional SA-based food packaging films.

Hydrogen-Bonding-Induced H-Aggregation of Charge-Transfer Complexes for Ultra-Efficient Second Near-Infrared Region Photothermal Conversion

Hydrogen-Bonding-Induced H-Aggregation of Charge-Transfer Complexes for Ultra-Efficient Second Near-Infrared Region Photothermal Conversion

A novel sodium alginate active films functionalized with purple onion peel extract (Allium cepa)

The purple onion peel extracts (POPE) have a high content of phenolic compounds and can be used as a promising strategy in the development of active packaging. Biodegradable sodium alginate films have good characteristics of gel formation, flexibility, transparency, brightness, and low oil permeability. The incorporation of bioactive compounds from plant residues can be a low-cost technique to functionalize alginate-based materials. The aim of this work was to evaluate the effects of POPE incorporation on the physical, mechanical, barriers, antioxidants, and antimicrobial properties of alginate-based films. Filmogenic solutions were prepared with a concentration of 0, 10, 20, and 30% of POPE and glycerol was used as plasticizer. The addition of POPE in the sodium alginate matrix promoted the development of opaque red films, with a content of phenolic compounds 43 times greater than the film without extract. As expected, the incorporation of POPE increased the antioxidant activity and the thickness of the alginate-based films. In addition, the incorporation of phenolic compounds promoted better interaction between the polymeric networks, reducing the water solubility of the alginate films. The results indicated that the sodium alginate films incorporated with several concentration of POPE have been shown to be an interesting material for the production of active packaging, being possible to apply them in foods with high water activity or susceptible to lipid oxidation, to preserve and extend the shelf life of these products. • Phenolic extracts from the purple onion peel were obtained and incorporated on alginate-based films. • Changes in the mechanical, physical and barrier properties of the alginate-based films were observed. • Alginate films functionalized with purple onion peel extract showed lower solubility. • High antioxidant activity was obtained by adding the phenolics extracts in alginate films. • Films can be used to reduce oxidation and increase the shelf life of food products.

Antimicrobial and antioxidant activity of impregnated pectin and alginate based bio composite packaging material for fresh produce safety

The objective of the presented work was to develop, characterize and evaluate the biodegradable, proactive, protective, novel active packaging blend films of low methoxy pectin and sodium alginate and identify their antimicrobial and antioxidant ability with plant-based natural phytochemicals like cinnamaldehyde. Different blend films were prepared in different ratio like (75% pectin ± 25% sodium alginate) (100% pure pectin), (100% pure sodium alginate), (100% Pectin+200µL cinnamaldehyde), 75% pectin+25 sodium alginate+700µL cinnamaldehyde), The antimicrobial activity was tested against foodborne pathogens E. coliO157:H7 (MTCC 90), and Salmonella Typhi (MTCC 733) and zone of inhibition were recorded. On the basis of linear correlation analysis (R2), the free radical scavenging activity of 10% bio-composite incorporated with 0.30% cinnamaldehyde blends was 0.9235 for DPPH scavengers where citric acid were used as a positive control. The film was characterized by TGA, DSC, FTIR, and XRD analysis result was shown a significant effect on thermal behavior.

Effect of citric acid and plasma activated water on the functional properties of sodium alginate for potential food packaging applications

In this study, cold plasma activated water (PAW) was used in the preparation of sodium alginate (SA) solution and the effect of reactive oxygen and nitrogen species (RONS), low pH and high oxidation-reduction potential on the functional properties of SA films was evaluated. Citric acid (CA) was added to SA, and the combined effect of PAW and CA on the functional properties of SA films was assessed. With 0.5, 1 and 2 w/v% addition of CA, tensile strength (TS) of the SA films decreased by 32, 58 and 66 %, while the elongation at break (EB) increased by 150, 275 and 475 %. The, TS and EB of SA films increased by 43 and 66 % when PAW was used to prepare SA solutions. Addition of glycerol reduced the TS and tensile modulus, while the EB was increased. The linear viscoelastic region (LVE) of SA decreased with the addition of CA and glycerol. However, addition of PAW increased the LVE region. The 1 and 2 % CA and PAW containing samples showed higher storage modulus as compared to the control samples and no intersection was observed between storage and loss modulus. The CA and/or PAW containing solutions showed shear thinning properties. The water vapour transmission rate (WVTR) of SA decreased by 34 % with the addition of 1 % CA, while only 12 % reduction was observed for 0.5 and 2 % CA containing samples. A further reduction in WVTR to 44 % was observed as PAW was added to 1 % CA containing SA samples.

Elucidation of Mechanical, Physical, Chemical and Thermal Properties of Microbial Composite Films by Integrating Sodium Alginate with Bacillus subtilis sp.

Materials are the foundation in human development for improving human standards of life. This research aimed to develop microbial composite films by integrating sodium alginate with Bacillus subtilis. Sodium alginate film was fabricated as control. The microbial composite films were fabricated by integrating 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 g of Bacillus subtilis into the sodium alginate. Evaluations were performed on the mechanical, physical, chemical and thermal properties of the films. It was found that films reinforced with Bacillus subtilis significantly improved all the mentioned properties. Results show that 0.5 g microbial composite films had the highest tensile strength, breaking strain and toughness, which were 0.858 MPa, 87.406% and 0.045 MJ/m3, respectively. The thickness of the film was 1.057 mm. White light opacity, black light opacity and brightness values were 13.65%, 40.55% and 8.19%, respectively. It also had the highest conductivity, which was 37 mV, while its water absorption ability was 300.93%. Furthermore, it had a higher melting point of 218.94 °C and higher decomposition temperature of 252.69 °C. SEM also showed that it had filled cross-sectional structure and smoother surface compared to the sodium alginate film. Additionally, FTIR showed that 0.5 g microbial composite films possessed more functional groups at 800 and 662 cm−1 wavenumbers that referred to C–C, C–OH, C–H ring and side group vibrations and C–OH out-of-plane bending, respectively, which contributed to the stronger bonds in the microbial composite film. Initial conclusions depict the potential of Bacillus subtilis to be used as reinforcing material in the development of microbial composite films, which also have the prospect to be used in electronic applications. This is due to the conductivity of the films increasing as Bacillus subtilis cell mass increases.

Controlled Drug Release from Sodium Alginate Film Dosage Forms

Controlled Drug Release from Sodium Alginate Film Dosage Forms

Physical, mechanical, optical, barrier, and antioxidant properties of sodium alginate–aloe vera biocomposite film

Composite films of sodium alginate and aloe vera gel were prepared using sorbitol as a plasticizer. These films were studied for their physical, mechanical, barrier, optical, and antioxidant properties. The results of the study showed a direct relationship between aloe vera gel concentrations and total phenolic contents of the composite films. The phenolic compounds present in aloe vera contribute to the antioxidant properties of the composite films. The results also indicated that the antioxidant activity of the composite films increased with the increasing concentration of aloe vera reaching a maximum value at the maximum (50%) concentration of aloe vera gel. The influence of aloe vera in enhancing tensile strength was found to be more prominent, giving a maximum value of tensile strength at only 10% concentration of aloe vera gel. The results also showed that the incorporation of aloe vera gel into sodium alginate up to a concentration of 50% did not significantly alter the transparency of the composite films. The water vapor permeability of the films decreased with the increasing concentration of aloe vera in the films. The solubility of the films increased with the increasing concentration of aloe vera due to the presence of highly water-soluble compounds in aloe vera gel. Novelty impact statement Novel food packaging films based on two natural resources, that is, alginate and aloe vera have been developed. Owing to their excellent transparency and colorlessness these films visually resemble synthetic plastic films but have a distinct advantage over synthetic packaging materials, of being biodegradable and edible. By the virtue of their good mechanical strength, barrier properties, and antioxidant activity these biodegradable active packaging films are a strong candidate to replace the synthetic plastic materials presently being used in the food packaging industry which contribute to environmental pollution.

Disintegration Properties and Drug Release Profiles of Sodium Alginate Films Containing Rebamipide

Disintegration Properties and Drug Release Profiles of Sodium Alginate Films Containing Rebamipide

Characterization of sodium alginate-based films incorporated with thymol for fresh-cut apple packaging

The non-antibacterial and relatively poor mechanical properties of sodium alginate film limit its application for fresh-cut fruit packaging. The phenolic compound thymol has prominent antioxidant and antibacterial activities. The physical and functional properties of thymol/sodium alginate composite films and their ability to preserve fresh-cut apples were investigated. Thymol/sodium alginate composite films were observed to have high tensile strength, elongation at break and UV–vis light blocking capability, but low water vapor permeability, water solubility, and swelling ratio compared with standard sodium alginate film without thymol. The composite films also showed notable scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals. In addition, the composite films exhibited remarkable inhibition of the growth of Staphylococcus aureus and Escherichia coli. Furthermore, thymol/sodium alginate films could effectively reduce weight loss, retain nutrition and surface color of fresh-cut apple slices. Therefore, sodium alginate films with thymol have strong potential as a cling wrap material used in the packaging of fresh-cut fruits.

Structural studies and bioactivity of sodium alginate edible films fabricated through ferulic acid crosslinking mechanism

Abstract Sodium alginate (SA) is a well-known naturally occurring seaweed biopolymer and the attracted interest of SA is proficient to develop a characteristic edible film which extended the shelf-life of fruits, vegetables, poultry, and seafood. The objective of the current study focuses on the fabrication and characterization of sodium alginate edible films crosslinked with ferulic acid (FA) at 25, 35, 45 mg/gm of SA and classified as FA150, FA210, FA270. These FA allied SA films are found to be transparent, homogeneous, stable, and more rigid due to the crosslinking of ferulic acid. Further, the experimental films were evaluated to understand the effect of ferulic acid on their characteristic changes i.e., thickness, opacity, water-solubility, solid mass, and moisture content. Likewise, the Tensile strength (TS) and elongation at break percent (E%) are also tested to estimate the film's barrier and physical strength. The intermolecular interactions, microstructure, and surface morphology profiles of developed films were studied using standard Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) experimental parameters. Moreover, the FA linked SA edible films were shown potential antioxidant activity profiles with increased concentration of crosslinking agent (ferulic acid) through reducing both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric ions. Whereas, the developed FA linked SA composite films did not show a potential zone of inhibition against the most common food spoiling bacteria i.e., Klebsiella pneumonia and Salmonella enterica. Thus, the current study endorsed that the FA allied sodium alginate edible films are beneficial for the manufacturing and food processing applications with a key antioxidant function.