Nanostructured poly(lactic acid)/soy protein/HPMC films by electrospinning for potential applications in food industry

The potential of nanofibrillated cellulose from Hevea brasiliensis to produce films for bio-based packaging

Cellulose micro/nanofibril (MNFC) films are an interesting alternative to plastic-based films for application in biodegradable packaging. In this study, we aimed to produce and characterize MNFC films obtained from alkaline-pretreated rubberwood (Hevea brasiliensis) waste and Eucalyptus sp. commercial pulp. MNFC and films were evaluated regarding microstructure; crystallinity; stability; and physical, optical, mechanical, and barrier properties. A combined quality index (QI) was also calculated. Eucalyptus MNFC suspensions were more stable than H. brasiliensis. Both films had a hydrophobic surface (>90°) and high grease resistance (oil kit 12). H. brasiliensis films had lower transparency (26.4 %) and high crystallinity (∼89 %), while Eucalyptus films had lower permeability and higher mechanical strength. The QI of MNFC was 51 ± 5 for H. brasiliensis and 55 ± 4 for Eucalyptus, showing that both types of raw material have potential for application in the packaging industry and in the reinforcement of composites, as well as for high value-added applications in products made from special materials.

Lignin-containing cellulose nanocrystals enhanced electrospun polylactic acid-based nanofibrous mats: Strengthen and toughen

Biodegradable polylactic acid (PLA) nanofibrous mats prepared by electrospinning serve as suitable packaging materials. However, their practical applications are limited by their weak mechanical properties, poor thermal stability, and high cost. In this study, green and low-cost lignin-containing cellulose nanocrystals (LCNCs) with different lignin contents were developed and employed as reinforced materials to synergistically enhance the thermal, mechanical, and hydrophobic properties of PLA electrospun nanofibrous mats. The presence of moderate lignin improved the interfacial compatibility between the LCNCs and PLA, resulting in excellent mechanical properties of the nanofibrous mats. Compared to pure PLA mats, the tensile strength of the composites reached up to 21.0 MPa, representing a 6.6-fold increase. Its toughness was synchronously enhanced by 16 times, reaching a maximum of 3.6 MJ/m3. The maximum decomposition temperature of PLA/LCNCs electrospun nanofibrous mats increased from 339 °C to 365 °C. Furthermore, the increase in lignin in the LCNCs positively contributed to improving the hydrophobicity of the PLA/LCNCs electrospun nanofibrous mats. This bio-based strategy of LCNCs employed in the enhancement of fully bio-based PLA nanofibrous mats offers a viable approach for the advancement of packaging films.

Batch preparation and characterization of zein-based beaded nanofiber membranes for active food packaging

Active packaging can efficiently enhance the shelf life of food, realizing the encapsulation and effective release of antibacterial agents and antioxidants. Zein is a natural protein derived from corn, widely used in food packaging. In this work, zein-based nanofiber membranes (NFMs) with beaded structures for food packaging were fabricated in batch using a self-made free surface electrospinning. The characteristics of NFMs were investigated in terms of their morphologies, structures and properties. The results illustrated that the antioxidant activity of NFMs was significantly improved after adding licorice extracts. Moreover, after adding the eugenol to the zein/licorice extract NFMs, zein/licorice extract/eugenol (ZLE) NFM had outstanding antibacterial activities against Staphylococcus aureus and Escherichia coli, which effectively prolonged the shelf-life of the grapes when it was used to package grapes. It proved that ZLE NFM had great potential in food packaging applications.

Natural polysaccharides and proteins-based films for potential food packaging and mulch applications: A review

Conventional nondegradable packaging and mulch films, after reaching the end of their use, become a major source of waste and are primarily disposed of in landfills. Accumulation of non-degradable film residues in the soil leads to diminished soil fertility, reduced crop yield, and can potentially affect humans. Application of degradable films is still limited due to the high cost, poor mechanical, and gas barrier properties of current biobased synthetic polymers. In this respect, natural polysaccharides and proteins can offer potential solutions. Having versatile functional groups, three-dimensional network structures, biodegradability, ease of processing, and the potential for surface modifications make polysaccharides and proteins excellent candidates for quality films. Besides, their low-cost availability as industrial waste/byproducts makes them cost-effective alternatives. This review paper covers the performance properties, cost assessment, and in-depth analysis of macromolecular structures of some natural polysaccharides and proteins-based films that have great potential for packaging and mulch applications. Proper dissolution of biopolymers to improve molecular interactions and entanglement, and establishment of crosslinkages to form an ordered and cohesive polymeric structure can help to obtain films with good properties. Simple aqueous-based film formulation techniques and utilization of waste/byproducts can stimulate the adoption of affordable biobased films on a large-scale.

Electrospun plant protein-based nanofibers in food packaging

Electrospinning is a relatively simple technology capable to produce nano- and micron-scale fibers with different properties depending on the electrospinning conditions. This review critically investigates the fabrication of electrospun plant protein nanofibers (EPPNFs) that can be used in food and food packaging applications. Recent progress in the development and optimization of electrospinning techniques for production of EPPNFs is discussed. Finally, current challenges to the implementation of EPPNFs in food and food packaging applications are highlighted, including potential safety and scalability issues. The production of plant protein nanofibers and microfibers is likely to increase in the future as many industries wish to replace synthetic materials with more sustainable, renewable, and environmentally friendly biopolymers. It is therefore likely that EPPNFs will find increasing applications in various fields including active food packaging and drug delivery.

Electrospun Nanofibers for Functional Food Packaging Application

With the strengthening of the public awareness of food safety and environmental protection, functional food packaging materials have received widespread attention. Nanofibers are considered as promising packaging materials due to their unique one-dimensional structure (high aspect ratio, large specific surface area) and functional advantages. Electrospinning, as a commonly used simple and efficient method for preparing nanofibers, can obtain nanofibers with different structures such as aligned, core-shell, and porous structures by modifying the devices and adjusting the process parameters. The selection of raw materials and structural design of nanofibers can endow food packaging with different functions, including antimicrobial activity, antioxidation, ultraviolet protection, and response to pH. This paper aims to provide a comprehensive review of the application of electrospun nanofibers in functional food packaging. Advances in electrospinning technology and electrospun materials used for food packaging are introduced. Moreover, the progress and development prospects of electrospun nanofibers in functional food packaging are highlighted. Meanwhile, the application of functional packaging based on nanofibers in different foods is discussed in detail.

Synthesis and Characterization of a Novel Composite Edible Film Based on Hydroxypropyl Methyl Cellulose Grafted with Gelatin

A novel composite edible film was synthesized by grafting gelatin chain onto hydroxypropyl methyl cellulose (HPMC) in the presence of glycerol (used as a plasticizer) using a solution polymerization technique. The reaction was carried out in homogeneous aqueous medium. Thermal properties, chemical structure, crystallinity, surface morphology, and mechanical and hydrophilic performance changes of HPMC caused by the addition of gelatin were investigated by differential scanning calorimetry, thermogravimetric, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, universal testing machine and water contact angle. The results shows that HPMC and gelatin are miscible and the hydrophobic property of the blending film can be enhanced with the introduction of the gelatin. Moreover, the HPMC/gelatin blend films are flexible, and exhibit excellent compatibility, good mechanical properties and also thermal stability, and could be promising candidates for food packaging materials.

Bilayer Films of Poly(lactic acid) and Cottonseed Protein for Packaging Applications

Poly(lactic acid) (PLA) is a common biobased film-former made from renewable biomass, such as polysaccharides from sugarcane, corn, or cassava. It has good physical properties but is relatively expensive when compared to the plastics used for food packaging. In this work, bilayer films were designed, incorporating a PLA layer and a layer of washed cottonseed meal (CSM), an inexpensive agro-based raw material from cotton manufacturing, where the main component is cottonseed protein. These bilayer films were made through the solvent casting method. The combined thickness of the PLA/CSM bilayer film was between 47 and 83 μm. The thickness of the PLA layer in this film was 10%, 30%, or 50% of the total bilayer film’s thickness. Mechanical properties of the films, opacity, water vapor permeation, and thermal properties were evaluated. Since PLA and CSM are both agro-based, sustainable, and biodegradable, the bilayer film may be used as an eco-friendlier food packaging material, which helps reduce the environmental problems of plastic waste and microplastics. Moreover, the utilization of cottonseed meal may add value to this cotton byproduct and provide a potential economic benefit to cotton farmers.

Introduction of Curdlan Optimizes the Comprehensive Properties of Methyl Cellulose Films

The good oxygen barrier and hydrophobic properties of curdlan (CL) film might be suitable complements for MC film, and its similar glucose unit and thermal-gel character might endow the methyl cellulose (MC)/CL blended system with compatibility and good comprehensive properties. Thus, MC/CL blended films were developed. The effects of MC/CL blend ratios on the microstructures and physical properties of the blends were characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), oxygen and water vapor permeability testing, dynamic mechanical analysis (DMA), light transmittance testing, tensile testing, hydrophilic property testing, and water solubility testing. The introduction of CL affected the molecular aggregation and crystallization of the MC molecules, suggesting MC-CL molecular interactions. The cross-sectional roughness of the MC/CL film increased with an increase in CL content, while the surface of the MC/CL 5:5 film was smoother than those of the MC/CL 7:3 and 3:7 films. Only one glass transition temperature, which was between that of the MC and CL films, was observed for the MC/CL 7:3 and MC/CL 5:5 films, indicating the good compatibility of the MC and CL molecules at these two blend ratios. The hydrophobicity and water insolubility increased with the CL content, which was due to the combined effects of more hydrophobic cavities in the CL triple-helix and increased surface roughness. Increased oxygen barrier properties with increasing CL content might be a combined effect of the increased hydrogen bonds and hydrophilic ektexines of the CL triple-helix. The elongations of the blended films were higher than those of the MC film, which might be related to its increased water content. The MC/CL 7:3 and MC/CL 5:5 films retained the good light transmittance and tensile strength of the MC film, which corresponded well to their good compatibility and might be due to the effects of the MC-CL molecular interactions and the relative smooth morphologies. MC/CL 5:5 showed improved water vapor barrier properties, which might be due to its smooth surface morphologies. This research offers new MC based films with improved properties and good compatibility, providing great potential for use as edible coatings, capsules, and packaging materials.

Facile fabrication of transparent high-barrier poly(lactic acid)-based bilayer films with antioxidant/antimicrobial performances

Poly(lactic acid) (PLA) has been intended as an encouraging biopolymer for packaging purposes. Nevertheless, PLA-based films suffer from low gas barrier properties, which restrict their applications. Here, we report a facile fabrication of multi-component coating via layer deposition of cinnamaldehyde (CIN)-doped chitosan/poly(vinyl alcohol)/fish gelatin (CPF) on PLA surfaces. Different PLA/CPF ratios (100:0, 77.5:22.5, 55:45, 32.5:67.5, and 0:100) were tested, whereas the PLA55:CPF45 was selected for loading of CIN. The surface and morphology analyses of the bilayers verify that CPF layers are successfully coated on the PLA surfaces. This design improved the mechanical strength and water barrier of CPF films and simultaneously enhanced the ductility of PLA films. By deposition of CIN-doped CPF layer on a PLA substrate, the oxygen permeability decreased from 28.92 to 0.238 cm³ mm/m² day bar, approximately 122 times lower than that of bare PLA. CIN loadings in the CPF layer endowed bilayer films with antioxidant/antimicrobial activity.

Designing Double-Layer Multi-Material Composite Patch Scaffold with Adhesion Resistance for Hernia Repair

Hernia repair mesh is associated with a number of complications, including adhesions and limited mobility, due to insufficient mechanical strength and non-resorbability. Among them, visceral adhesions are one of the most serious complications of patch repair. In this study, a degradable patch with an anti-adhesive layer was prepared for hernia repair by 3D printing and electrospinning techniques using polycaprolactone (PCL), polyvinyl alcohol (PVA), and soybean peptide (SP). The study into the physicochemical properties of the patch was found that it had adequate mechanical strength requirements (16 N cm^-1 ) and large elongation at break, which were superior than commercial polypropylene (PP) patches. In vivo and in vitro experiments showed that human umbilical vein endothelial cells (HUVECs) proliferated well on composite patches, and showed excellent biocompatibility with the host and little adhesion through a rat abdominal wall defect model. In conclusion, the results of this study show that composite patch can effectively reduce the occurrence of adhesions, while the addition of SP in the patch further enhances its biocompatibility. We believe that a regenerative biological patch with great potential in hernia repair provides a new strategy for the development of new biomimetic biodegradable patches. This article is protected by copyright. All rights reserved.

Active Composite Packaging Reinforced with Nisin-Loaded Nano-Vesicles for Extended Shelf Life of Chicken Breast Filets and Cheese Slices

To meet the demands for more effective and ecofriendly food packaging strategies, the potential of nisin-loaded rhamnolipid functionalized nanofillers (rhamnosomes) has been explored after embedding in hydroxypropyl-methylcellulose (HPMC) and κ-carrageenan (κ-CR)-based packaging films. It was observed that intrinsically active rhamnosomes based nanofillers greatly improved the mechanical and optical properties of nano-active packaging (NAP) films. Incorporation of rhamnosomes resulted in higher tensile strength (5.16 ± 0.06 MPa), Young’s modulus (2777 ± 0.77 MPa), and elongation (2.58 ± 0.03%) for NAP than active packaging containing free nisin (2.96 ± 0.03 MPa, 1107 ± 0.67 MPa, 1.48 ± 0.06%, respectively). NAP demonstrated a homogenous distribution of nanofillers in the biopolymer matrix as elucidated by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) confirmed that NAP prepared with nisin-loaded rhamnosomes was thermally stable even above 200 °C. Differential scanning calorimetry (DSC) analyses revealed that addition of nisin in nanofillers resulted in a slight increase in Tg (108.40 °C), indicating thermal stability of NAP. Fourier transform infrared spectroscopy (FTIR) revealed slight shift in all characteristic bands of nano-active packaging, which indicated the embedding of rhamnosomes inside the polymer network without any chemical interaction. Finally, when tested on chicken breast filets and cheese slices under refrigerated storage conditions, NAP demonstrated broad-spectrum antimicrobial activity (up to 4.5 log unit reduction) and inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. These results suggest that HPMC and κ-CR-based NAP containing functionalized nanofillers can serve as an innovative packaging material for the food industry to improve the safety, quality, and shelf-life of dairy and meat products.

Optimization of Soybean Protein Extraction Using By-Products from NaCl Electrolysis as an Application of the Industrial Symbiosis Concept

Defatted soybean flour is generated during the oil extraction process of soybean, and it has a protein content of ~50%. On the other hand, an alkaline solution of NaOH is produced during the electrolysis process of NaCl in a novel method used to make a potent disinfectant/antiseptic (HOCl). In the present work, we suggest using these two products to produce soy protein isolate (SPI), aiming to create an industrial symbiosis. A Box–Behnken experimental design was executed, and a surface response analysis was performed to optimize temperature, alkaline solution, and time used for SPI extraction. The SPI produced at optimal conditions was then characterized. The experimental results fit well with a second-order polynomial equation that could predict 93.15% of the variability under a combination of 70 °C, alkaline solution 3 (pH 12.68), and 44.7 min of the process. The model predicts a 49.79% extraction yield, and when tested, we obtained 48.30% within the confidence interval (46.66–52.93%). The obtained SPI was comparable in content and structure with a commercial SPI by molecular weight and molecular spectroscopy characterization. Finally, the urease activity (UA) test was negative, indicating no activity for trypsin inhibitor. Based on the functional properties, the SPI is suitable for food applications.

Active PLA Packaging Films: Effect of Processing and the Addition of Natural Antimicrobials and Antioxidants on Physical Properties, Release Kinetics, and Compostability

The performance characteristics of polylactic acid (PLA) as an active food packaging film can be highly influenced by the incorporation of active agents (AAs) into PLA, and the type of processing technique. In this review, the effect of processing techniques and the addition of natural AAs on the properties related to PLA performance as a packaging material are summarized and described through a systematic analysis, giving new insights about the relation between processing techniques, types of AA, physical–mechanical properties, barriers, optical properties, compostability, controlled release, and functionalities in order to contribute to the progress made in designing antioxidant and antimicrobial PLA packaging films. The addition of AAs into PLA films affected their optical properties and influenced polymer chain reordering, modifying their thermal properties, functionality, and compostability in terms of the chemical nature of AAs. The mechanical and barrier performance of PLA was affected by the AA’s dispersion degree and crystallinity changes resulting from specific processing techniques. In addition, hydrophobicity and AA concentration also modified the barrier properties of PLA. The release kinetics of AAs from PLA were tuned, modifying diffusion coefficient of the AAs in terms of the different physical properties of the films that resulted from specific processing techniques. Several developments based on the incorporation of antimicrobial and antioxidant substances into PLA have displayed outstanding activities for food protection against microbial growth and oxidation.

Biocompatibility of electrospun cell culture scaffolds made from balangu seed mucilage/PVA composites

Synthesis of Balangu (Lallemantia royleana) seed mucilage (BSM) solutions combined with polyvinyl alcohol (PVA) was studied for the purpose of producing 3D electrospun cell culture scaffolds. Production of pure BSM nanofibers proved to be difficult, yet integration of PVA contributed to a facile and successful formation of BSM/PVA nanofibers. Different BSM/PVA ratios were fabricated to achieve the desired nanofibrous structure for cell proliferation. It is found that the optimal bead-free ratio of 50/50 with a mean fiber diameter of ≈180 nm presents the most desirable scaffold structure for cell growth. The positive effect of PVA incorporation was approved by analyzing BSM/PVA solutions through physiochemical assays such as electrical conductivity, viscosity and surface tension tests. According to the thermal analysis (TGA/DSC), incorporation of PVA enhanced thermal stability of the samples. Successful fabrication of the nanofibers is verified by FT-IR spectra, where no major chemical interaction between BSM and PVA is detected. The crystallinity of the electrospun nanofibers is investigated by XRD, revealing the nearly amorphous structure of BSM/PVA scaffolds. The MTT assay is employed to verify the biocompatibility of the scaffolds. The cell culture experiment using epithelial Vero cells shows the affinity of the cells to adhere to their nanofibrous substrate and grow to form continuous cell layers after 72 h of incubation.

Electrospun nanofiber based on Ethyl cellulose/Soy protein isolated integrated with bitter orange peel extract for antimicrobial and antioxidant active food packaging

The present work was aimed to produce a novel bioactive nanofiber (NFs) based on Ethyl cellulose (EC), Soy protein isolated (SPI), and containing Bitter orange peel extract (BOPE) by electrospinning technology. The EC/SPI NFs were formulated with different weight ratios of 1:1, 2:1, and 1:2 denoted as ES11, ES21, and ES12, respectively, and investigated by several analyses. Based on the obtained results, the maximum hydrogen interactions between these two polymers, ES11 NFs offered a uniform morphology without bead with the diameter of 185.33 nm as a result of the compatibility of the polymer solutions of EC and SPI. Moreover, appropriate thermal stability was presented along with more porosity (78%), maximum water vapor transmission rate (657 g/m2.24h), good tensile stress (6.12 MPa), and acceptable water contact angel (82.3°). Therefore, ES11 NFs were selected as the optimal sample for incorporation of the BOPE as the antibacterial and antioxidant agent. According to the antioxidant activity test, the highest concentration (20% wt) of this extract increased the antioxidant activity of NF around 64.7% and also inhibited the growth of pathogenic bacteria (S. areus, and E. coli). Therefore, the ES11 electrospun NFs containing 20% BOPE can be a beneficial system to increase the safety and quality of foods.

Bio-based multilayer films: A review of the principal methods of production and challenges

The development of biodegradable packaging materials has been drawing attention worldwide to minimize the environmental impact of traditional petroleum-based plastics. Nevertheless, it is challenging to obtain bio-based materials with suitable properties for packaging applications. Films produced from a single biopolymer often lack some important properties. An alternative to overcome this limitation is the multilayer assembly. Under this technology, two or more materials with specific and complementary properties are combined into a single-layered structure, thus improving the performance of bio-polymer plastics. This review presents the main aspects of bio-based multilayer film production technologies, discussing their advantages and disadvantages, which have to be considered to produce the most suitable film for each specific application. Most of the studies reported that such films resulted in increased mechanical performance and decreased water, oxygen, and dioxide carbon permeability. This approach allows the addition of compounds leading to antioxidant or antibacterial activity. Finally, a discussion about the future challenges is also presented.

Natural antimicrobials and antioxidants added to polylactic acid packaging films. Part I: Polymer processing techniques

Currently, reducing packaging plastic waste and food losses are concerning topics in the food packaging industry. As an alternative for these challenges, antimicrobial and antioxidant materials have been developed by incorporating active agents (AAs) into biodegradable polymers to extend the food shelf life. In this context, developing biodegradable active materials based on polylactic acid (PLA) and natural compounds are a great alternative to maintain food safety and non-toxicity of the packaging. AAs, such as essential oils and polyphenols, have been added mainly as antimicrobial and antioxidant natural compounds in PLA packaging. In this review, current techniques used to develop active PLA packaging films were described in order to critically compare their feasibility, advantages, limitations, and relevant processing aspects. The analysis was focused on the processing conditions, such as operation variables and stages, and factors related to the AAs, such as their concentrations, weight losses during processing, and incorporation technique, among others. Recent developments of active PLA-based monolayers and bi- or multilayer films were also considered. In addition, patents on inventions and technologies on active PLA-based films for food packaging were reviewed. This review highlights that the selection of the processing technique and conditions to obtain active PLA depends on the type of the AA regarding its volatility, solubility, and thermosensitivity.

The fabrication of a novel film based on polycaprolactone incorporated with chitosan and rutin: potential as an antibacterial carrier for rainbow trout packaging

ABSTRACT

Rutin and chitosan could be utilized in the food industry owing to their antioxidant and antibacterial properties. This study was carried out to fabricate novel films using polycaprolactone (PCL-sole), PCL and chitosan (PCL-CS), PCL and rutin (PCL-R), and PCL, chitosan, and rutin (PCL-CS-R) through electros pinning method. Physical properties, in vitro antibacterial and antioxidant properties of the films, and their antibacterial activity on rainbow trout were further investigated. The PCL-CS, PCL-R, and PCL-CS-R had smaller fiber diameter and film thickness and lower viscosity while they showed higher surface tension, water contact angle, and conductivity and better antibacterial and antioxidant properties compared with PCL-sole film (P < 0.05). The PCL-CS-R film respectively decreased 17.45%, 19.27%, and 18.39% more populations of L. monocytogenes, S. aureus, and E. coli compared to PCL-sole film in the fish samples. Therefore, the PCL-CS-R film can be potentially used in active packaging because of its antioxidant and antibacterial activities.

GRAPHIC ABSTRACT

Soy Protein: Molecular Structure Revisited and Recent Advances in Processing Technologies

Rising health concerns and increasing obesity levels in human society have led some consumers to cut back on animal protein consumption and switch to plant-based proteins as an alternative. Soy protein is a versatile protein supplement and contains well-balanced amino acids, making it comparable to animal protein. With sufficient processing and modification, the quality of soy protein can be improved above that of animal-derived proteins, if desired. The modern food industry is undergoing a dynamic change, with advanced processing technologies that can produce a multitude of foods and ingredients with functional properties from soy proteins, providing consumers with a wide variety of foods. This review highlights recent progress in soy protein processing technologies. Using the current literature, the processing-induced structural changes in soy protein are also explored. Furthermore, the molecular structure of soy protein, particularly the crystal structures of β-conglycinin and glycinin, is comprehensively revisited.

Effect of different ionic liquids acting as plasticizers on the multi-scale structures and physical properties of hydroxypropyl methylcellulose/monosodium phosphate photophobic film

Different ionic liquid (IL)s were added to hydroxypropyl methylcellulose /monosodium phosphate (HPMC/MSP) photophobic film to improve its ductility, and their effects on its multi-scale structures and physical properties were studied. After adding these ILs, smoothness of the fractal structure, tensile strength, modulus of the film did not change obviously, while the crystallinity, the number of holes, and elongation increased, the hole size and T_g decreased. Compared to films with other ILs, the film with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF₄) showed the largest elongation and crystallinity, the smallest hole size, the least holes, and highest whiteness. The film with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) showed the largest water content and the lowest T_g. The increased elongation proved that all these ILs could improve the ductility of the film, among which, [EMIM]BF₄ had the strongest plasticizing effect.

Development of a novel reinforced film based on gellan gum/cellulose nanofiber/soy protein for skin tissue engineering application

Recently, the importance of using biocompatible nanocomposite film with suitable properties has attracted interest for use in potential applications in the biomedical area.

Monitoring freshness of chicken breast by using natural halochromic curcumin loaded chitosan/PEO nanofibers as an intelligent package

Intelligent packaging is important to get information about real time quality of foods. The objective of this study was to develop an electrospun nanofiber halochromic pH sensor film using curcumin, chitosan (CS) and polyethylene oxide (PEO) to monitor chicken freshness. Conductivity and rheological behavior of CS/PEO/curcumin solutions were measured to understand the effect of solution properties on the morphology of the fibers. The morphological characteristics of nanofiber films were investigated by Field Emission Scanning Electron Microscopy (FESEM). Average diameter of the fibers was found to be between 283 ± 27 nm and 338 ± 35 nm. It was concluded that increasing CS amount in nanofibers decreased the diameter of the fibers. Thermal analysis and water vapor permeability features of the pH sensor were also examined. Color changes of curcumin loaded CS/PEO nanofiber film was evaluated on chicken breast package at 4 °C. The color of nanofiber film changed from bright yellow to reddish color which provided an opportunity to detect color changes by even the naked eyes of the untrained consumer. As a quality indicator, surface pH changes of the chicken breast and TVB-N (total volatile basic nitrogen) were measured. At the end of the day 5, pH value of 6.53 ±0.08 and TVB-N concentration of 23.45 ±3.35 mg/100 g indicated that food was at the edge of the acceptance level. As a result, curcumin loaded nanofiber satisfied the expectation and gave an opportunity to visualize real time monitoring of chicken spoilage.

Application of blocking and immobilization of electrospun fiber in the biomedical field

The fiber obtained by electrospinning technology is a kind of biomaterial with excellent properties, which not only has a unique micro-nanostructure that gives it a large specific surface area and porosity, but also has satisfactory biocompatibility and degradability (if the spinning material used is a degradable polymer). These biomaterials provide a suitable place for cell attachment and proliferation, and can also achieve immobilization. On the other hand, its large porosity and three-dimensional spatial structure show unique blocking properties in drug delivery applications in order to achieve the purpose of slow release or even controlled release. The immobilization effect or blocking effect of these materials is mainly reflected in the hollow or core-shell structure. The purpose of this paper is to understand the application of the electrospun fiber based on biodegradable polymers (aliphatic polyesters) in the biomedical field, especially the immobilization or blocking effect of the electrospun fiber membrane on cells, drugs or enzymes. This paper focuses on the performance of these materials in tissue engineering, wound dressing, drug delivery system, and enzyme immobilization technology. Finally, based on the existing research basis of the electrospun fiber in the biomedical field, a potential research direction in the future is put forward, and few suggestions are also given for the technical problems that urgently need to be solved.

Long-Term Antibacterial Effect of Electrospun Polyvinyl Alcohol/Polyacrylate Sodium Nanofiber Containing Nisin-Loaded Nanoparticles

Response Surface Methodology (RSM) was used to assess the optimal conditions for a Water/Oil/Water (W/O/W) emulsion for encapsulated nisin (EN). Nano-encapsulated nisin had high encapsulation efficiencies (EE) (86.66 ± 1.59%), small particle size (320 ± 20 nm), and low polydispersity index (0.27). Biodegradable polyvinyl alcohol (PVA) and polyacrylate sodium (PAAS) were blended with EN and prepared by electrospinning. Scanning electron microscopy (SEM) revealed PVA/PAAS/EN nanofibers with good morphology, and that their EN activity and mechanical properties were enhanced. When the ultrasonication time was 15 min and 15% EN was added, the nanofibers had optimal mechanical, light transmittance, and barrier properties. Besides, the release behavior of nisin from the nanofibers fit the Korsemeyer–Peppas (KP) model, a maximum nisin release rate of 85.28 ± 2.38% was achieved over 16 days. At 4 °C, the growth of Escherichia coli and Staphylococcus aureus was inhibited for 16 days in nanofibers under different ultrasonic times. The application of the fiber in food packaging can effectively inhibit the activity of food microorganisms and prolong the shelf life of strawberries, displaying a great potential application for food preservation.

Targeting Delivery System for Lactobacillus Plantarum Based on Functionalized Electrospun Nanofibers

With the increased interest in information on gut microbes, people are realizing the benefits of probiotics to health, and new technologies to improve the viability of probiotics are still explored. However, most probiotics have poor resistance to adverse environments. In order to improve the viability of lactic acid bacteria, polylactic acid (PLA) nanofibers were prepared by coaxial electrospinning. The electrospinning voltage was 16 kV, and the distance between spinneret and collector was 15 cm. The feed rates of the shell and core solutions were 1.0 and 0.25 mL/h, respectively. The lactic acid bacteria were encapsulated in the coaxial electrospun nanofibers with PLA and fructooligosaccharides (FOS) as the shell materials. Scanning electron microscopy, transmission electron microscopy, and laser scanning confocal microscopy showed that lactic acid bacteria were encapsulated in the coaxial electrospun nanofibers successfully. The water contact angle test indicated that coaxial electrospun nanofiber films had good hydrophobicity. An in vitro simulated digestion test exhibited that the survival rate of lactic acid bacteria encapsulated in coaxial electrospun nanofiber films was more than 72%. This study proved that the viability of probiotics can be improved through encapsulation within coaxial electrospun PLA nanofibers and provided a novel approach for encapsulating bioactive substances.

Characterization of curcumin incorporated guar gum/orange oil antimicrobial emulsion films

Edible films are manufactured from natural, renewable, nontoxic, and biodegradable polymers and are safe alternatives to plastic food packaging. Despite ongoing research, biopolymer-based edible films still are not at a quality to ensure total commercial replacement of synthetic packaging materials. The study aims to compare the effectiveness of some novel methods employed to improve edible film properties. These include dispersion of orange oil (1% & 2% v/v) and/or curcumin into guar gum (GG), glycerol and lecithin-based edible films that are further reinforced with Sodium trimetaphosphate (STMP) crosslinking with the aim enhancing films physical properties. The films were characterized by measurement of film thickness, density, moisture content, water dissolvability, FTIR Spectroscopy, opacity, water vapor permeability, tensile properties, and antimicrobial activity. Orange oil and curcumin preserved their antimicrobial activity inside the films, which bestowed the films with an active packaging function. Control GG films had acceptable tensile and barrier properties that were further improved. All other film properties, such as opacity, dissolvability, and moisture content, that should be designed for specific application, were successfully modified with the methods used. Our results confirm successful application of STMP crosslinking, emulsion film formation, and active agent addition to edible films in manufacturing GG films for packaging.

Preparation and characterization of arginine-modified chitosan/hydroxypropyl methylcellose antibacterial film

Chitosan and its derivatives are widely used in medical, cosmetic and food fields. In this study, chitosan-N-arginine (CSA) was synthesized and characterized by Fourier-transform infrared (FT-IR), ¹H NMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). A novel antibacterial composite film consisting of CSA, hydroxypropyl methylcellose (HPMC) and glycerol was then prepared. The transparent and homogeneous film presented good compatibility between CSA and HPMC, confirmed by SEM. The thickness of the film was about 44.8 μm and its moisture content was 23.0%. Antimicrobial evaluation of CSA/HPMC film showed 9.0 mm bacteriostatic diameter zone against E. coli and 10.5 mm one against S. aureus. The film exhibited cell biocompatibility and promoted proliferation with L929 cell cytotoxicity test. Both antibacterial and cytotoxic results showed that the CSA/HPMC film was a promising material for medication, cosmetics and food preservation applications.