Development and characterization of food-grade electrospun fibers from amaranth protein and pullulan blends

Mapping deterioration in electrospun zein nonwoven nanostructures encapsulating corn oil

Electrospun nonwovens of biopolymers are gaining popularity in filtration, coatings, encapsulation, and packaging materials. However, their applications are hindered by limited stability, particularly when loaded with lipids. This research aimed to apply a multiscale approach to gain insights into deteriorative processes, e.g., oxidation, limiting the shelf life of these complex materials, using corn oil-loaded electrospun zein nonwovens as a model system. Oil-doped zein electrospun nonwovens were stored in the dark at 23 °C and 33% relative humidity for 28 days and tested at selected intervals to monitor their morphology and mechanical properties. Lipid oxidation was assessed using the thiobarbituric acid reactive species (TBARS) assay. The photophysical properties of intrinsic, i.e., tyrosine (Tyr), and extrinsic, i.e., boron-dipyrromethene undecanoic acid 581/591 (BODIPY C11), lumiphores were also monitored to evaluate changes in local molecular rigidity, and oxidation, respectively. The protein secondary structure was determined with Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) analysis of the oil-loaded electrospun nonwovens revealed that the diameter of the ribbon-like fiber significantly decreased during storage from 701 ± 23 nm to 620 ± 44 nm. Breakage of the electrospun fibers was observed and correlated with increased brittleness and molecular rigidity of the nonwoven material, reflected by an increase in Tyr emission intensity and phosphorescence lifetime. Changes in tensile strength, brittleness and matrix rigidity also correlated with a zein secondary structure transition from unordered to ordered β-sheets. Raman and luminescence micrographs showed oil migration during storage, thereby increasing lipid oxidation. The correlation between local rigidity and lipid distribution/oxidation suggests that reorganizing protein structures increased material brittleness and displaced encapsulated oils within the electrospun fiber. Understanding deteriorative mechanisms aids in developing innovative strategies to improve the stability of these novel food-grade materials.

Optimization of pullulan production by Aureobasidium pullulans using semi-solid-state fermentation and artificial neural networks: Characterization and antibacterial activity of pullulan impregnated with Ag-TiO2 nanocomposite

This study presents a novel and efficient approach for pullulan production using artificial neural networks (ANNs) to optimize semi-solid-state fermentation (S-SSF) on faba bean biomass (FBB). This method achieved a record-breaking pullulan yield of 36.81 mg/g within 10.82 days, significantly exceeding previous results. Furthermore, the study goes beyond yield optimization by characterizing the purified pullulan, revealing its unique properties including thermal stability, amorphous structure, and antioxidant activity. Energy-dispersive X-ray spectroscopy and scanning electron microscopy confirmed its chemical composition and distinct morphology. This research introduces a groundbreaking combination of ANNs and comprehensive characterization, paving the way for sustainable and cost-effective pullulan production on FBB under S-SSF conditions. Additionally, the study demonstrates the successful integration of pullulan with Ag@TiO2 nanoparticles during synthesis using Fusarium oxysporum. This novel approach significantly enhances the stability and efficacy of the nanoparticles by modifying their surface properties, leading to remarkably improved antibacterial activity against various human pathogens. These findings showcase the low-cost production medium, and extensive potential of pullulan not only for its intrinsic properties but also for its ability to significantly improve the performance of nanomaterials. This breakthrough opens doors to diverse applications in various fields.

Fabrication and characterisation of collagen/pullulan ultra-thin fibers by electrospinning

Collagen electrospun fibers are promising materials for food packaging and tissue engineering. The conventional electrospinning of collagen, however, is usually carried out by dissolving it in organic reagents, which are toxic. In this study, collagen/pullulan (COL/PUL) ultra-thin fibers were prepared by electrospinning using acetic acid as a solvent. Compared to the conventional preparation method, the proposed method is safe and does not produce toxic solvent residues. The introduction of PUL increased the degree of molecular entanglement in the solution, so the viscosity of the COL/PUL electrospun solution increased from 0.50 ± 0.01 Pa∙s to 4.40 ± 0.08 Pa∙s, and the electrical conductivity decreased from 1954.00 ± 1.00 mS/cm to 1372.33 ± 0.58 mS/cm. Scanning electron microscopy analysis confirmed that PUL improved the spinnability of COL, and smooth, defect-free COL/PUL ultra-thin fibers with diameters of 215.32 ± 40.56 nm and 240.97 ± 53.93 nm were successfully prepared at a viscosity of greater than 1.18 Pa∙s. As the proportion of PUL increased, intramolecular hydrogen bonds became the dominant interaction between COL and PUL. The intermolecular hydrogen bonding content decreased from 52.05 % to 36.45 %, and the intramolecular hydrogen bonding content increased from 46.11 % to 62.95 %. The COL was gradually unfolded, the content of α-helices decreased from 33.57 % to 25.91 % and the random coils increased from 34.22 % to 40.09 %. More than 36 % of the triple helix fraction of COL was retained by the COL/PUL ultra-thin fibers, whereas only 16 % of the triple helix fraction of COL was retained by the COL nanofibers prepared with 2.2.2-trifluoroethanol. These results could serve as a reference for the development of green food COL-based fibers.

Agro-Industrial Plant Proteins in Electrospun Materials for Biomedical Application

Plant proteins are receiving a lot of attention due to their abundance in nature, customizable properties, biodegradability, biocompatibility, and bioactivity. As a result of global sustainability concerns, the availability of novel plant protein sources is rapidly growing, while the extensively studied ones are derived from byproducts of major agro-industrial crops. Owing to their beneficial properties, a significant effort is being made to investigate plant proteins' application in biomedicine, such as making fibrous materials for wound healing, controlled drug release, and tissue regeneration. Electrospinning technology is a versatile platform for creating nanofibrous materials fabricated from biopolymers that can be modified and functionalized for various purposes. This review focuses on recent advancements and promising directions for further research of an electrospun plant protein-based system. The article highlights examples of zein, soy, and wheat proteins to illustrate their electrospinning feasibility and biomedical potential. Similar assessments with proteins from less-represented plant sources, such as canola, pea, taro, and amaranth, are also described.

Fabrication and characterization of octenyl succinic anhydride modified pullulan micelles for encapsulating curcumin

BACKGROUND

Curcumin has become increasingly popular in functional foods and beverages field as a result of its high biological activity. Nevertheless, the application of curcumin is usually limited by its poor water solubility, low absorption, rapid metabolism and instability. Accordingly, the development of an appropriate wall material is crucial for its effective use. In the present study, curcumin-octenyl succinic anhydride modified pullulan (Cur-OSAP) micelles were successfully prepared by an anti-solvent co-precipitation method.

RESULTS

Octenyl succinic anhydride modified pullulan (OSAP) micelles exhibited the highest encapsulation efficiency (57.31%) and loading capacity (5.73%) of curcumin when the mass ratio of OSAP to curcumin was 10:1 and the degree of substitution of OSAP was 0.0469, at which point Cur-OSAP micelles formed via hydrogen binding and hydrophobic interactions, as confirmed by Fourier transform infrared and fluorescence techniques. The transmission electron microscopy results showed that the Cur-OSAP micelles were roughly spherical in shape with diameters in the approximate range 30-60 nm.

CONCLUSION

The encapsulation of OSAP greatly improved photostability and sustained release properties of curcumin in Cur-OSAP micelles. These findings suggest that OSAP can be used as a carrier to encapsulate and protect hydrophobic food ingredients. © 2021 Society of Chemical Industry.

Nanoencapsulation of casein-derived peptides within electrospun nanofibres

BACKGROUND

Bioactive peptides derived from milk proteins are recognized as functional foods, but their consumption is limited by undesirable or bitter flavour, poor stability, and low bioavailability. Electrospinning is a versatile process for encapsulation of various bioactive compounds in the form of nanosized fibres, which can circumvent these disadvantages. This study was aimed at the preparation of casein-derived peptides-loaded nanofibres through electrospinning and characterizing them for fortification of milk.

RESULTS

Pullulan at 100, 120, and 140 g kg^-1 concentrations was used for electrospinning of peptides. Scanning electron and atomic force micrographs revealed the formation of clean bead-free peptides-loaded pullulan nanofibres at 120 and 140 g kg^-1 concentrations with mean diameter of 60.45-133.05 nm and encapsulation efficiency of 72.95-86.04%. Fourier transform infrared spectra and X-ray diffractograms revealed the absence of interactions between the functional groups of pullulan and peptides during electrospinning. The zeta potential of the peptides-loaded nanofibres ranged from -15.6 to -24.6 mV, and the hydrodynamic diameter varied from 118.7 to 256.2 nm. The peptides from electrospun nanofibres showed sustained release to the extent of 75.3% after 8 h in gastrointestinal pH conditions. The release kinetics of peptides from nanofibres was best fitted to a Peppas-Sahlin model (R²  = 0.987), and through diffusion and erosion mechanisms. The antioxidant activity of pure peptides and those from nanofibres was comparable. The physico-chemical qualities of milk fortified with encapsulated peptides did not show noticeable difference either.

CONCLUSIONS

From the morphological, ultrastructural, particle size, encapsulation efficiency, release kinetics, and antioxidant activity data, it was inferred that electrospinning could be an effective technique for nanoencapsulation of casein-derived bioactive peptides. These peptides-loaded nanofibres could be used for fortification of milk and milk products. © 2021 Society of Chemical Industry.

Evaluation of Freeze Drying and Electrospinning Techniques for Saffron Encapsulation and Storage Stability of Encapsulated Bioactives

Saffron extract was encapsulated into a gelatin matrix by means of electrospinning and freeze drying techniques and the degradation kinetics of bioactive compounds were evaluated during their storage at 4, 24, and 35 °C as compared to non-encapsulated control. The encapsulation efficiency, thermal properties, storage stability, morphology, and diameter distribution of the encapsulated saffron extract were evaluated as output parameters. In general, both encapsulation techniques demonstrated superior retention of bioactive compounds compared to samples without encapsulation during the entire storage period. Electrospinning and freeze drying techniques were able to retain at least 96.2 and 93.7% of crocin, respectively, after 42 days of storage at 35 °C with the 15% saffron extract. The half-life (t1/2) time parameter for the control sample (with 15% saffron extract without encapsulation) was 22 days at 4 °C temperature, while that encapsulated by electrospinning was 138 days and that obtained for freeze drying was 77 days, The half-lives were longer at lower temperatures. The encapsulation efficiency of crocin, picrocrocin, and safranal associated with the electro-spun gelatin fibers were 76.3, 86.0, and 74.2%, respectively, and in comparison, the freeze drying encapsulation efficiencies were relatively lower, at 69.0, 74.7, and 65.8%, respectively. Electro-spun gelatin fibers also had higher melting and denaturation temperatures of 78.3 °C and 108.1 °C, respectively, as compared to 65.4 °C and 93.2 °C, respectively, for freeze-dried samples. Thus, from all respects, it was concluded that electrospinning was a better and more effective technique than freeze drying in terms of preserving saffron bioactive compounds.

Plant protein-based fibers: Fabrication, characterization, and potential food applications

Proteins from plants have been considered as safer, healthier, and more sustainable resources than their animal counterparts. However, incomplete amino acid composition and relatively poor functionality limit their applications in foods. Structuring plant proteins to fibrous architectures enhances their physicochemical properties, which can favor various food applications. This review primarily focuses on fabrication of fibers from plant proteins via self-assembly, electrospinning, solution blow spinning, wet spinning, and high-temperature shear, as well as on several applications where such fibrous proteins assemble in quality foods. The changes of protein structure and protein-protein interactions during fiber production are discussed in detail, along with the effects of fabrication conditions and protein sources on the morphology and function of the fibers. Self-assembly requires proteolysis and subsequent peptide aggregation under specific conditions, which can be influenced by pH, salt and protein type. The spinning strategy is more scalable and produces uniformed fibers with larger length scales suitable for encapsulation, food packaging and sensor substrates. Significant progress has been made on high-temperature shear (including extrusion)-induced fibers responsible for desirable texture in meat analogues. Structuring plant proteins adds values for broadened food applications, but it remains challenging to keep processes cost-effective and environmentally friendly using food grade solvents.

Antimicrobial and physicochemical characterization of 2,3-dialdehyde cellulose-based wound dressings systems

Biobased and biodegradable films were prepared by physically mixing 2,3-dialdehyde cellulose (DAC) with two other biopolymers, zein and gelatin, in three different proportions. The antimicrobial activities of the composite blends against Gram-positive and Gram-negative bacteria increase with the increase of DAC content. Cell viability tests on mammalian cells showed that the materials were not cytotoxic. In addition, DAC and gelatin were able to promote thermal degradation of the blends. However, DAC increased the stiffness and decreased the glass transition temperature of the blends, while gelatin was able to decrease the stiffness of the film. Morphological analysis showed the effect of DAC on the surface smoothness of the blends. The contact angle confirmed that all blends were within the range of hydrophilic materials. Although all the blends showed impressive performance for wound dressing application, the blend with gelatin might be more suitable for this purpose due to its better mechanical performance and antibacterial activity.

Electrospinning of glutelin-hordein incorporated with Oliveria decumbens essential oil: Characterization of nanofibers

In this study, electrospinning of hordein and glutelin extracted from barley was carried out. Different ratios of the glutelin-hordein blends (25:75, 30:70, 35:65) were tested and the operation parameters including voltage, ejection flow rate and needle-to-collector distance were optimized. According to the scanning electron microscope images, the glutelin-hordein 25:75 blend generated at the voltage of 15 kV, the needle-to-collector distance of 150 mm and the ejection rate of 1 mL/h was selected for the fabrication of uniform nanofibers. The apparent viscosity at the ejection point was decreased with increasing the glutelin concentration from 25 to 35 %. Moreover, the Oliveria decumbens essential oil (ODEO) with different loading concentrations (2-4 % (v/v)) was incorporated into the protein blend. Fourier-transform infrared spectra demonstrated the occurrence of the interactions of proteins the ODEO. The encapsulation efficiency of ODEO in the nanofibers was 79.30 %. The presence of ODEO led to inhibition the growth of Staphylococcus aureus, Escherichia coli and Bacillus cereus in a synthetic medium. The optimal nanofibers showed high antioxidnat activity. The results herein showed the possibility of the production of electrospun nanofibers using barley proteins with promising (bio)functionalities for the active food packaging applications.

Encapsulation of sea buckthorn (Hippophae rhamnoides L.) leaf extract via an electrohydrodynamic method

Polyphenols from the leaves of sea buckthorn (Hippophae rhamnoides L.) are nutritious and bioactive substances that can be used as nutritional supplements. To improve their stability and bioaccessibility in vivo, chemical extracts of sea buckthorn leaves were, for the first time, encapsulated using electrohydrodynamic technology. The microcapsules were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The extract and microcapsules were evaluated for total phenols and flavonoids, total antioxidant activity, and their inhibitory effects on metabolic syndrome-related enzymes (α-glucosidase, α-amylase, and pancreatic lipase) under in vitro simulated digestion. The results indicated that the extract was successfully encapsulated; encapsulation protected polyphenols and flavonoids from degradation and increase their bioaccessibility in the intestine. The antioxidant activity and the inhibition of metabolic syndrome-related enzymes were better reserved after encapsulation. Our findings will help in promoting the potential of sea buckthorn as a nutritional supplement and expanding its commercial use.

Effect of pullulan concentration and pH on the interactions between whey protein concentrate and pullulan during gelation

BACKGROUND

Whey protein concentrate (WPC)/pullulan (PUL) hydrogel is applied as a microencapsulation wall material to protect probiotics. However, the interactions between WPC and PUL during gelation have not been clarified. In the present study, the effects of PUL concentration and pH on the interactions between WPC and PUL during gelation were evaluated with respect to appearance, zeta-potential, sulfhydryl group amount, surface hydrophobicity and infrared spectroscopy measurements. The rheological properties of WPC/PUL gels were also determined.

RESULTS

The results obtained showed that a proper concentration (0.40 g mL^-1 ) of PUL could improve the gel by enhancing the strength of hydrogen bonding, electrostatic interactions and exposure of hydrophobic groups, whereas too much PUL inhibited the formation of disulfide bonds. Furthermore, hydrophobic interactions, disulfide bonds and hydrogen bonds were destroyed in varying degrees under an alkaline environment. The rheological results also demonstrated a similar effect of PUL concentration and pH on the storage modulus (G') of WPC/PUL gels.

CONCLUSION

When the WPC/PUL gel was formed at PUL concentration of 0.40 g mL^-1 and pH 7.0, the interaction between WPC and PUL could be enhanced, which is beneficial for the future application of WPC/PUL gels in the food industry. © 2020 Society of Chemical Industry.

Alternatives to Meat and Dairy

The increasing size and affluence of the global population have led to a rising demand for high-protein foods such as dairy and meat. Because it will be impossible to supply sufficient protein to everyone solely with dairy and meat, we need to transition at least part of our diets toward protein foods that are more sustainable to produce. The best way to convince consumers to make this transition is to offer products that easily fit into their current habits and diets by mimicking the original foods. This review focuses on methods of creating an internal microstructure close to that of the animal-based originals. One can directly employ plant products, use intermediates such as cell factories, or grow cultured meat by using nutrients of plant origin. We discuss methods of creating high-quality alternatives to meat and dairy foods, describe their relative merits, and provide an outlook toward the future.

Strategies to Improve the Properties of Amaranth Protein Isolate-Based Thin Films for Food Packaging Applications: Nano-Layering through Spin-Coating and Incorporation of Cellulose Nanocrystals

In this work, two different strategies for the development of amaranth protein isolate (API)-based films were evaluated. In the first strategy, ultrathin films were produced through spin-coating nanolayering, and the effects of protein concentration in the spin coating solution, rotational speed, and number of layers deposited on the properties of the films were evaluated. In the second strategy, cellulose nanocrystals (CNCs) were incorporated through a casting methodology. The morphology, optical properties, and moisture affinity of the films (water contact angle, solubility, water content) were characterized. Both strategies resulted in homogeneous films with good optical properties, decreased hydrophilic character (as deduced from the contact angle measurements and solubility), and improved mechanical properties when compared with the neat API-films. However, both the processing method and film thickness influenced the final properties of the films, being the ones processed through spin coating more transparent, less hydrophilic, and less water-soluble. Incorporation of CNCs above 10% increased hydrophobicity, decreasing the water solubility of the API films and significantly enhancing material toughness.

Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties

Fibers produced by electrospinning from biocompatible, biodegradable and naturally occurring polymers have potential advantages in drug delivery and biomedical applications because of their unique functionalities. Here, electrospun submicron fibers were produced from mixtures containing an exopolysaccharide (pullulan) and a small molecule with hosting abilities, hydroxypropyl-β-cyclodextrin (HP-β-CD), thus serving as multi-functional blend. The procedure used water as sole solvent and excluded synthetic polymers. Rheological characterization was performed to evaluate the impact of HP-β-CD on pullulan entanglement concentration (CE); the relationship with electrospinnability and fiber morphology was investigated. Neat pullulan solutions required three times CE (~20% w/v pullulan) for effective electrospinning and formation of bead-free nanofibers. HP-β-CD (30% w/v) facilitated electrospinning, leading to the production of continuous, beadless fibers (average diameters: 853-1019 nm) at lower polymer concentrations than those required in neat pullulan systems, without significantly shifting the polymer CE. Rheological, Differential Scanning Calorimetry (DSC) and Dynamic Light Scattering (DLS) measurements suggested that electrospinnability improvement was due to HP-β-CD assisting in pullulan entanglement, probably acting as a crosslinker. Yet, the type of association was not clearly identified. This study shows that blending pullulan with HP-β-CD offers a platform to exploit the inherent properties and advantages of both components in encapsulation applications.

Introducing nano/microencapsulated bioactive ingredients for extending the shelf-life of food products

The shelf-life of foods is affected by several aspects, mainly chemical and microbial events, resulting in a considerable decline in consumer's acceptance. There is an increasing interest to substitute synthetic preservatives with the plant-based bioactive ingredients which are safe and natural. However, full implementation of this replacement is postponed by some challenges associated with bioactive ingredients, including their low chemical stability, off-flavor, low solubility, and short-term effectiveness. Encapsulation could overcome these limitations. The present review explains current trends in applying natural encapsulated ingredients for food preservation based on a classified description including essential oils, plant extracts, phenolics, carotenoids, etc. and their application for extending food shelf-life mostly dealing with antimicrobial, ant-browning and antioxidant properties. Encapsulation techniques, especially nanoencapsulation, is a promising strategy to overcome their limitations. Moreover, better results are obtained using a combination of proteins and polysaccharides as wall materials than single polymers. The encapsulation method and type of encapsulants highly influences the releasing mechanism and physicochemical properties of bioactive ingredients. These factors together with optimizing the conditions of encapsulation process leads to a cost-effective and well encapsulated ingredient which is more efficient than its free form in shelf-life improvement. It has been shown that the well-designed encapsulation systems, finally, boost the shelf-life-promoting functions of the bioactive ingredients, mostly due to enhancing their solubility, homogeneity in food matrices and contact surface with deteriorative agents, and providing their prolonged presence over food storage and processing via increasing the thermal and processing stability of bioactive compounds, as well as controlling their release on food surfaces, or/and within food packages. To this end and given the numerous wall and bioactive core substances available, further studies are needed to evaluate the efficiency of many encapsulated forms of both conventional and novel bioactive ingredients in food shelf-life extending since the interactions and anti-spoiling behaviors of the ingredients in various encapsulation systems and foodstuffs are highly variable that should be optimized and characterized before any industrial application.

Fabrication and Characterization of Gelatin Electrospun Fiber Containing Cardamom Essential Oil

Background:

Gelatin electrospun fibers incorporated with extracted cardamom Essential Oil (EO) were developed and characterized.

Materials & Methods:

The gelatin solutions were evaluated in terms of conductivity, morphology, fourier transform infrared spectroscopy, and the effect of cardamom EO on the gelatin fibers. Cardamom EO showed significant antioxidant activity with IC50 value of 5 μg/mL. The extract contained several active components including Cyclohexene, 1-methyl-4-(1-methylethylidene) and Eucalyptol (1.8-cineol) as the most abundant components.

Results:

The images of the scanning electron microscopy revealed formation of nanofibers from gelatin solution with significant entanglement. Furthermore, discrete beads were appeared by increasing the concentrations of cardamom EO in the gelatin fibers. Reduction in conductivity parameter of EO solutions could explain the observed defects. The fourier transform infrared spectra showed the formation of hydrogen bonds in gelatin fibers. The infrared as well as spectrophotometric spectra confirmed that EO was effectively involved in electrospun fibers.

Conclusion:

In conclusion, gelatin –a natural biopolymer, incorporated with cardamom EO forms smooth fabricated electrospun nanofibers.

Development of a scalable procedure by a discontinuous crossflow DF/UF to obtain a concentrate of chenopodin from a dead-end centrifugal UF at bench scale

The aim of this study was to develop a scalable crossflow diafiltration/ultrafiltration procedure for quinoa 11S globulin purification starting at the bench scale using Ultra15 centrifugal filter devices. The electrophoretic profiles of centrifugal ultrafiltration fractions showed a high heterogeneity in the bands, while crossflow ultrafiltration reduced the phenomena of protein sticking to the membrane, avoiding aggregate formation. In the crossflow protein concentration, flux decline curves were studied according to Hermia's fouling mechanisms and the resistance in a series model. High reversible resistance was related to external mechanisms due to complete blockage of the membrane surface followed by cake formation. The crossflow ultrafiltration was the most efficient technique for obtaining 57 kDa chenopodin isolate with higher processing capacity, purity and protein yield. The diafiltration/ultrafiltration process proved to be adequate and easy to handle to scale up the production of the 11S quinoa globulin.

Fabrication and characterization of a novel polysaccharide based composite nanofiber films with tunable physical properties

In this study, the pullulan/ethyl cellulose composite nanofiber films with tunable physical properties were fabricated by blend electrospinning process. The solution properties of polysaccharide polymers were investigated and related with the morphology of the nanofiber films, and the results showed that the addition of ethyl cellulose caused decreasing viscosity and conductivity of solutions, which gave rise to the smaller fiber diameter. The Fourier transform infrared spectroscopy indicated that pullulan and ethyl cellulose chains interacted with each other through hydrogen bonding. X-ray diffraction analysis showed that electrospinning process retarded the crystallization of polysaccharide molecules. Thermal analysis showed that the composite nanofiber films possessed higher melting temperature and degradation temperature than the pure pullulan nanofiber film. Water contact angle and water stability test proved that the composite nanofiber films possessed tunable surface wettability (94.6°-120.1°) and improved water stability. The mechanical test showed that the composite nanofiber films had enhanced mechanical strength.

Protein-Polysaccharide Composite Materials: Fabrication and Applications

Protein-polysaccharide composites have been known to show a wide range of applications in biomedical and green chemical fields. These composites have been fabricated into a variety of forms, such as films, fibers, particles, and gels, dependent upon their specific applications. Post treatments of these composites, such as enhancing chemical and physical changes, have been shown to favorably alter their structure and properties, allowing for specificity of medical treatments. Protein-polysaccharide composite materials introduce many opportunities to improve biological functions and contemporary technological functions. Current applications involving the replication of artificial tissues in tissue regeneration, wound therapy, effective drug delivery systems, and food colloids have benefited from protein-polysaccharide composite materials. Although there is limited research on the development of protein-polysaccharide composites, studies have proven their effectiveness and advantages amongst multiple fields. This review aims to provide insight on the elements of protein-polysaccharide complexes, how they are formed, and how they can be applied in modern material science and engineering.

Derivatization approaches and applications of pullulan

Pullulan (PUL), a linear exo-polysaccharide, is useful in industries as diverse as food, cosmetics and pharmaceuticals. PUL presents many favorable characteristics, such as renewable origin, biocompatibility, stability, hydrophilic nature, and availability of reactive sites for chemical modification. With an inherent affinity to asialoglycoprotein receptors, PUL can be used for targeted drug delivery to the liver. Besides, these primary properties have been combined with modern synthetic approaches for developing multifunctional biomaterials. This is evident from numerous studies on approaches, such as hydrophobic modification, cross-linking, grafting and transformation as a polyelectrolyte. In this review, we have discussed up-to-date advances on chemical modifications and emerging applications of PUL in targeted theranostics and tissue engineering. Besides, we offer an overview of its applications in food, cosmetics and environment remediation.

Fast dissolving oral films for drug delivery prepared from chitosan/pullulan electrospinning nanofibers

In this study, Chitosan/pullulan composite nanofiber fast dissolving oral films (FDOFs) were prepared via electrospinning technology. The ratio of chitosan/pullulan (C/P) had an influence on solution property and nanofiber morphology, with the increase of chitosan, viscosity and conductivity of solutions increased, the morphology obtained by scanning electron microscopy indicated that the diameter of nanofibers decreased initially then increased. The Fourier transform infrared spectra indicated hydrogen bond interactions between chitosan and pullulan molecules. X-ray diffraction analysis proved that electrospinning process decreased the crystallinity of materials. Thermal analysis showed that melting point, degradation temperature and glass transition temperature increased with the addition of chitosan content in the FDOF. Water solubility test proved that the FDOF can dissolve in water completely within 60 s. Finally, in order to prove its practicability in future, a model drug of aspirin was encapsulated in the FDOF successfully.

Electrospinning and electrospraying technologies for food applications

Electrospinning and electrospraying are versatile techniques for the production of nano- to micro-scale fibers and particles. Over the past 2 decades, significant progresses have been made to advance the fundamental understandings of these electrohydrodynamic processes. Researchers have investigated different polymeric and non-polymeric substrates for producing submicron electrospun/electrosprayed materials of unique morphologies and physicochemical properties. This chapter provides an overview on the basic principles of electrospinning and electrospraying, highlighting the effects of key processing and solution parameters. Electrohydrodynamic phenomena of edible substrates, including polysaccharides (xanthan, alginate, starch, cyclodextrin, pullulan, dextran, modified celluloses, and chitosan), proteins (zein, what gluten, whey protein, soy protein, gelatin, etc.), and phospholipids are reviewed. Selected examples are presented on how ultrafine fibers and particles derived from these substrates are being exploited for food and nutraceutical applications. Finally, the challenges and opportunities of the electrostatic methods are discussed.