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We describe colorimetric electrospun nanosensors designed to work at temperatures of 35–36°C. The mode of operations is based on a combination of the ability of dithizone to exhibit appropriate color and cholesteric liquid crystals presenting a wide range of melting points at various mixing ratios. To this end, different levels of dithizone (IUPAC name 1‐anilino‐3‐phenyliminothiourea), different ratios of cholesteric liquid crystals to cellulose acetate and cholesteryl oleyl carbonate to cholesteryl nanoate were defined as independent variables and the total color difference was considered as the response in the response surface methodology approach. The results showed that the range of color palette changes of the designed samples was diverse and could be applied to different products. As a case study, the applicability of the sensor was evaluated on the 4‐month shelf life of pistachio nuts at 35°C whilst the spoilage criteria were reconciled with the color changes in the designed sensor. [ABSTRACT FROM AUTHOR]

In this research, a dual encapsulation system was developed for loading niosomes into electrospun nanofibers of soy protein isolate (SPI)-polyvinyl alcohol (PVA); high hydrostatic pressure (HHP) was also applied to reinforce the nanofibers. For this purpose, different samples with various levels of HHP-treated SPI, PVA, and iron niosomes were prepared. Encapsulation efficiency as well as the bioavailability of iron increased in HHP-treated samples because HHP was able to disassemble the structure of the base polymers (SPI-PVA), allowing the iron to load into the skeleton of the base polymer and, consequently, encapsulated it in the structure strictly and suitably. HHP resulted in a higher transformation and bioavailability of SPI:PVA fibers, which is due to the destruction effect of this pretreatment on SPI and neutralizing its inhibitory effect. HHP eventuated lower Atomic Force Microscopy (AFM) indices in nanofibers because it can cause denaturation and aggregation of proteins, resulting in a more compact and homogeneous protein network. The results of this study are useful as a practical guide on how to prepare niosome-embedded SPI nanofibers (especially for the enrichment of plant-based nanofibers), what their properties are, and how to improve their characteristics through HHP pretreatment. [Display omitted] • A dual carrier for the iron encapsulation was developed for the first time. • Iron-loaded niosomes were encapsulated within electrospun nanofibers. • Dual encapsulation system resulted in the higher encapsulation efficiency of iron. • High hydrostatic pressure (HHP) improved electrical conductivity of feed solutions. • HHP enhanced iron bioavailability of niosome-embedded nanofibers. [ABSTRACT FROM AUTHOR]

In this research, the characteristics of the high hydrostatic pressure (HHP)-treated soy protein isolate (SPI) solutions as well as HHP-treated SPI (HSPI) electrospun fibers were comprehensively studied for the first time. For this purpose, surface tension, electrical conductivity, viscosity, zeta potential, and secondary structure of HSPI solutions at different ratios were investigated. Also, differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) of HHP-treated and non-treated SPI: PVA nanofibers were thoroughly compared. HHP denaturation reduced the size of nanofibers by 50–100 nm, diminished ordered structures and crystallinity of nanofibers, increased their melting point and induced hydrogen bonding between amino groups of denatured SPI and hydroxyl groups of PVA. These findings open a new horizon in the successful application of non-thermal energies in the electrospinning process to achieve appropriate fibers at nanoscale. [Display omitted] [ABSTRACT FROM AUTHOR]

There are difficulties with some traditional technologies for biopolymer coating of bioactive-loaded vesicular systems such as spray-drying and freeze-drying; high temperatures during spray drying can damage the loaded sensitive bioactives and freeze-drying is expensive. This is the driver for the adoption of emerging new technologies including electrohydrodynamic processing. In this review, the principles of electrospinning (ES) are briefly summarized and the characteristics of some important plant proteins used as electrospun fibers (EFs) are described with applications as meat analogues. Next, methods for encapsulation of different bioactives through ES techniques via meat analogue proteins are discussed: this is focused on the strength of encapsulation through vesicular systems. Finally, we examine how vesicular embedded EFs can be applied in different fields of antioxidant and antimicrobial food packaging as well as the enhancement of bioaccessibility and protection of loaded bioactives. Embedding liposomes into nanofibers causes better antioxidant and sensory properties as well as substantial reduction of bacterial load when applied as packaging layers; this technology also significantly enhances the photo-stability of bioactives. In addition, double encapsulation improves the long-term release of bioactives and can address the problem of burst release. Niosome-embedded EFs aid the sustained release of herbal bioactives and enhance their antimicrobial activity against Gram-positive/negative bacteria. The niosomes are distributed throughout the nanofibers evenly and are kept intact during ES process. [Display omitted] • Electro-encapsulation of fatty acids reduces their degradation rate. • Encapsulation of antioxidants via electrospinning preserves their antioxidant activity. • Embedding food-liposomes in electrospun fibers causes better sensory properties. • Niosomes immobilized in nanofibers aid the sustained release of herbal bioactives. [ABSTRACT FROM AUTHOR]

A common problem of electrospinning of plant proteins is that these kinds of proteins, including soy protein isolate (SPI), should be highly soluble and preferably in a random coil structure rather than the globular conformation. The current solution is to apply thermal treatment; however, it results in extensive organoleptic consequences (e.g. color degradation and off-flavor) and loss of nutrients. Thus, if a non-thermal technology such as high hydrostatic pressure (HHP) increases the disordered structure of the protein, it could facilitate the electrospinning of the protein and eliminate the barriers of thermal treatment, forming our hypothesis in this research. To this end, initially, extensive experiments including protein solubility, sulfhydryl content, turbidity, surface hydrophobicity, circular dichroism, and viscosity tests were carried out on HHP (200, 400 and 600 MPa) and thermally treated SPI samples (3.5% and 7% w/w). The results of sulfhydryl content revealed that disulfide bonds decreased at 400 MPa more intensely than other pressures while surface hydrophobic forces were promoted at this pressure. The circular dichroism test results showed that HHP treatment resulted in higher disordered structures and lower ordered ones, which is particularly helpful for the electrospinning process; besides, lower β-sheet content achieved by HHP treatment is especially useful for attaining defect-free fibers. For the first time, in this research, ideal electrospun fibers with average diameters of 300–400 nm were achieved through HHP processing, without using any thermal energy. [Display omitted] • Efficiency of HHP denaturation on SPI was compared with thermal denaturation. • Structural properties of SPI denatured by HHP were studied extensively. • HHP denaturation at 400 MPa resembled thermal denaturation of SPI sufficiently. • For the first time, HHP denaturation of SPI was followed by its electrospinning. [ABSTRACT FROM AUTHOR]

In this study, inclusion complexes (ICs) of menthol with various cyclodextrins (CDs) [α-CD, β-CD, γ-CD, (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), and methyl-β-cyclodextrin (M-β-CD)] were prepared, and the ICs with the highest encapsulation efficiency were applied in the electrospun gelatin mats to extend the release of menthol. Electrospinning feed solutions were evaluated based on surface tension, zeta potential, electrical conductivity, and rheological properties. The diameter and morphology of the pure gelatin and the CDs-loaded gelatin mats were analyzed using microscopy (FESEM and AFM). The results confirmed that CD loading leads to a decrease in the diameter of the nanofibers. The longest disintegration time belonged to the gelatin mat containing the β-CD complex. Comparison of the FTIR spectrum and XRD patterns of gelatin mats containing menthol-loaded CD complexes with the pure compounds confirmed the successful encapsulation of menthol inside the cavity of the CD, and the disappearance of the crystalline state of electrospun gelatin mats. Applying the electrospun gelatin mats as a fast-dissolving structure for the menthol-loaded inclusion complexes increased its thermal stability. In the bioadhesive test, the lowest force required to separate the gelatin mat from the skin model was obtained in the menthol-containing β-CD gelatin mat (6.21 ± 1.01 g). The menthol release from the pure gelatin mats was much faster than the electrospun mats containing CD complexes. Peppas-Sahlin and Fickian diffusion (Case-I) were the best-fitted model and menthol release mechanism, respectively. [Display omitted] • CDs were used to control the burst-release of menthol from electrospun gelatin mats. • Gelatin mat with β-CD showed the slowest release of menthol into the saliva. • The mat with β-CD required the lowest force to be separated from the skin model. • Electrospun mats showed higher thermal stability after including CD complexes. • Fickian diffusion (Case-I) was the release mechanism from the β-CD included mats. [ABSTRACT FROM AUTHOR]

A major limitation of gelatin feedstocks for industrial food and pharmaceutical applications is the lack of solubility at room temperature, necessitating use of drum/dry blending processes, combined with additives. Herein, electrospinning is investigated as an alternative route for producing cold water soluble 100% gelatin feedstock in place of powders. The physicochemical, rheological and functional properties of electrospun gelatin and an industrially available gelatin powder feedstocks were compared. Optimal conditions for producing gelatin nanofiber sheets were found to be 25% (w/v) polymer concentration in a binary solvent system of acetic acid: water (3:1 v/v), a spinning voltage of 25 kV, a flow rate of 0.5 ml/h and a tip-to-collector distance of 150 mm. The production of nanofibers from gelatin powder did not change the nature of the material. The glass transition temperature of gelatin nanofibers was lower than gelatin powder. Conversion of gelatin powder into nanofiber sheets also increased the dissolution rate in water at ambient temperature and promoted emulsion and foam forming ability, as well as increasing foam stability. Loss tangent measurements revealed that the gel formed by the gelatin nanofibers could be characterized as a weak gel. No difference was observed in the Young's modulus of samples made from gelatin nanofibers and powder, and the 0.2% (w/v) gelatin nanofiber sample yielded a higher viscosity than the 0.1% (w/v) concentration. Gelatin nanofibers have promising potential to be used as feedstock in food technology when cold water solubility and improved control of physical, functional and textural properties are required. Image 1 • The potential of gelatin nanofiber feedstocks in food technology is introduced. • Gelatin nanofibers dissolve in cold water in ~10 s. • The viscosity of gelatin solutions from nanofibres is higher than powders. • Compared to powders gelatin nanofibers provide greater foaming capability and stability. • The loss tangent for nanofiber produced gels is higher than for powders. [ABSTRACT FROM AUTHOR]

The aim of this study was to produce fast-dissolving fiber mats based on balangu seed gum (BSG) loaded with bergamot essential oil (BEO) using the electrospinning method. Stock solutions of BSG (0.5% w/v) and polyvinyl alcohol (PVA, 10% w/v) were mixed with different ratios (5:5, 4:6, 3:7, 2:8 and 1:9 v/v) and emulsified with 3% (w/w) essential oil and 1% (w/w) Tween-20. Increasing the BSG level in BSG-PVA mixtures resulted in higher electrical conductivity, surface tension and also consistency coefficient values. Based on the field emission scanning electron microscopy (FESEM) images, it was found that BSG to PVA ratios of 3:7 and 2:8 led to the production of fibers with appropriate morphological structure. The atomic force microscopy (AFM) images also confirmed the mat-like and bead-free structure of the fibers. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) proved that the BEO was physically entrapped in fiber mat structures without any adverse interaction with the encapsulant material. The fabricated mats could be dissolved in the aqueous medium within 5 s. The release kinetic of the loaded BEO was investigated in simulated aqueous tea medium. It was shown that the Fickian transfer phenomenon was the dominant mechanism involved in the release process. Giving a burst release to the flavoring agents, the designed system could be considered as a promising step in the food industry. Image 1 • Electrospun balangu nanofiber mat loaded with bergamot essential oil was produced. • Bergamot essential oil was physically entrapped in fiber mat structure. • The mats had a fast dissolving nature with a burst release of the flavoring agent. • The system could be considered as a strategy for enhancing the flavor in foods. [ABSTRACT FROM AUTHOR]

Although many papers have been published in recent years regarding the effects of electrospinning (ES) on the properties of legume proteins (LPs), there has been no comprehensive review summarizing these findings, which was the main aim of this paper. Thus, the main purpose of this article was to review the properties of LP fiber-forming solutions as well as LP fibers through different characterization methods. Furthermore, the effect of encapsulating/incorporating different components into the ES solution of various LPs was studied. Cross-linking significantly improves the thermal stability, barrier properties, and insolubility of LP nanofibers. Also, Maillard-induced glycation leads to higher surface tension at the interface of oil-water contact, smaller emulsion droplets, and monomodal distributions. The ES quality of LPs varies depending on the viscosity, electrical conductivity, and surface tension of the protein solution; Specifically, too low and too high viscosity are detrimental due to the formation of beads and delay in Taylor cone formation, respectively; too low or too high conductivity will also cause insufficient jet elongation and significantly reduced jet stability, respectively. Insertion of nanoparticles improves the mechanical and thermal stability of LP nanofibers; however, the extent to which the incorporation meets safety regulations for adoption in food destinations remains a major challenge. [Display omitted] • The properties of legume protein fiber-forming solutions were reviewed. • Recent innovations in the electrospinning of legume proteins were introduced. • The role of electrospun legume proteins fibers in food packaging was explained. • The challenges in the electrospinning of legume proteins were described. [ABSTRACT FROM AUTHOR]

This study aimed to develop a sandwich structure based on electrospun mats derived from gelatin (central layer) and Balangu seed gum (outer layers) and to compare its capability for prolonging the menthol release in the oral phase compared to the gelatin monolayer mat. The mesh-like structure and the smooth and uniform surface of the electrospun mats designed in this study were authenticated by Atomic Force Microscopy (AFM). By designing the sandwich structure, the dissolution time and contact angle of the mats were increased and their bioadhesive strength decreased. The swelling degree of the gelatin mat (453.25 ± 32.56%) was significantly higher than that of the sandwich mat (297.71 ± 22.68%) (p < 0.05). Successful entrapment and the thermal stability of the produced mats were proved by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR) tests. The release kinetics in the human simulated saliva showed that the burst release of menthol from the structure of electrospun gelatin mats, due to its fast-dissolving nature, was well prolonged by the designed sandwich system. The Fickian Case-I release was the main mechanism in the menthol release and the Peppas-Sahlin was the most suitable model governing the release of menthol from these structures. Unlabelled Image • Superhydrophilic multilayered nanofibers of balangu gum and gelatin was designed. • The designed multilayered structure prolonged the in vitro release of menthol. • Bioadhesion was decreased by sandwiching the gelatin mat between balangu gum layers. • The Fickian Case-I was the main mechanism for menthol release in saliva. • Sandwich structures control the burst release of fast-dissolving nanofibers. [ABSTRACT FROM AUTHOR]

In the present study, a protein-based halochromic nanosensor was designed to assess the quality of rainbow trout fillets. Zein nanofibers containing alizarin as the indicator dye were electrospun. The sensors were characterised using SEM, FT-IR, DSC, XRD, dye leaching, response time experiments and colorimetric analysis. TVB-N, TVC and pH of fish fillets were also measured over 12 days of storage at 4°C. FT-IR results showed that the alizarin was incorporated in the zein matrix by intermolecular hydrogen bonding. DSC graphs of zein based samples showed that the temperature of dehydration, glass transition and protein unfolding in the halochromic nanofibers were lower than in powdered zein. The amorphous structure of the zein samples was confirmed by XRD analysis. No color changes were occurred in the first 4 days of storage, but later, a light purple color could be observed in the sensor by the naked eye. The color of sensor became magenta by the 10th and 12th day of cold storage indicating spoilage. This fabricated halochromic nanosensor can monitor fish freshness in real time through color changes. The colorimetric results correlated well with microbial and chemical changes in the fish. Image 1 • A zein electrospun nanosensor successfully monitored trout fish freshness. • Trout fish spoilage induced alizarin color changes in zein nanofibers. • Colorimetric results agreed with the microbial level changes in the fish. • There is good correlation between TVBN levels and nanosensor color changes. • The nanosensor provides high sensitivity real-time alerts for trout at 4°C. [ABSTRACT FROM AUTHOR]