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Electrospinning is a simple, versatile method that employs an electrostatic force to produce fibers in the micro-to nanometer range using a wide variety of materials ranging from natural biopolymers to synthetics. Variations on the basic electrospinning set-up can be used to produce fibers demonstrating various morphological and functional properties advantageous for specific applications. Moreover, electrospun fibers created using naturally occurring polysaccharides have attracted much attention due to, but not limited to, their biological properties and sustainable sourcing. In this review, common variations on the basic electrospinning set-up are briefly discussed for their benefits in fiber morphology and upscaling capabilities. In depth, electrospun fibers made from polysaccharides; specifically alginate, cellulose, chitin and chitosan, starch, pullulan, hyaluronic acid, dextran, and levan; are discussed with an emphasis on the current research direction being taken for each of these materials. Moreover, current methods to increase electrospinnability for these polysaccharides are presented as well. Electrospun fibers can be specifically tailored for their function by the optimization of the electrospinning process and spinning dope. However, before the electrospinning process can be successfully upscaled on an industrial or commercial level, it is important to determine an effective method for increasing the rate of fiber production and, generally in the case of polysaccharides, increasing electrospinnability. Biopolymer fibers, specifically, demonstrate high potential in the biomedical field due to their biodegradability and compatibility properties. • Electrospinning technique is simple, versatile, and scalable. • Nanofibers successfully electrospun from various bio-based carbohydrate polymers. • Biopolymer nanofibers show many advantages for food and related applications. [ABSTRACT FROM AUTHOR]

• Starch-based nanofibers successfully electrospun from aqueous dispersions • Addition of pullulan aided in electrospinning of octenylsuccinylated (OS) starch • Electrospinnability of OS starches dictated mainly by rheological properties • Spinnability map of OS starch and pullulan established We aimed to develop a greener process for dry-electrospinning food-grade modified starch through the elimination of organic solvents. The rheological properties and electrospinnability of aqueous dispersions of commercial octenylsuccinylated (OS) starches with various molecular weight (Mw) were investigated, yet only nanofibers with beads or defects could be obtained from OS starch with the highest Mw, i.e., Purity Gum@ Ultra (PGU). Further improvement in the fiber morphology was achieved by adding pullulan (PUL) as a minor component in the spinning dope. Smooth, continuous, and bead-free nanofibers (147-250 nm) were obtained from the PGU-PUL dispersions. Shown on an electrospinnability map, the successful electrospinning of 12%, 15%, and 20% (w/v) aqueous PGU dispersions required a minimum addition of 6%, 5%, and 3% (w/v) of PUL, respectively. The addition of PUL contributed to establishing sufficient molecular entanglement for electrospinning. This study provides a promising green process to produce starch-based nanofibers for use in various applications, e.g., drug delivery, wound dressing, and tissue engineering. [ABSTRACT FROM AUTHOR]

The application of cinnamaldehyde essential oil (CEO), which is naturally antibacterial, has been limited due to its high volatility and insolubility in water. This issue may be addressed by nanoencapsulation through electrospinning. In this study, octenylsuccinylated starch (OSS) with different molecular structures blended with pullulan (PUL) was developed to load CEO for enhanced antibacterial potential. OSS with a smaller molecular size and a higher degree of substitution is beneficial for the electrospinning of OSS/PUL into high-quality nanofiber mats. The electrospinning process of OSS/PUL aqueous dopes is mainly influenced by moderate apparent viscosity, increased conductivity, and reduced surface tension. CEO loading through physical adsorption significantly changed the fiber microstructure and displayed antibacterial effects against Staphylococcus aureus , Escherichia coli , and Aspergillus flavus for electrospun OSS/PUL nanofiber mats. This study demonstrates that electrospun starch-based nanofiber mats with loading of essential oils could hold a potential application in active food packaging and wound dressing. [Display omitted] • Electrospinning of OSS with different molecular structure and PUL was explored. • Electrospinnability map of OSS/PUL aqueous dopes was studied systematically. • OSS with smaller R h and higher DS is beneficial for blending electrospinning. • CEO loading significantly improved the antibacterial activity of fiber mats. [ABSTRACT FROM AUTHOR]

The off-odor of seafood, which negatively affected its flavor and quality, was removed mainly by non-recyclable liquid-phase deodorization methods at present. In this work, octenylsuccinylated starch (OSS)-pullulan (PUL) nanofiber mats were regenerated after physical adsorption and thermal desorption of off-odor compounds in oyster peptides. The mat structure was characterized and the adsorption process was investigated. The regenerated nanofiber mats maintained a favorable appearance and microscopic morphology even after 25 adsorption-desorption cycles, with a reduction in average fiber diameter and average pore area, an increase in hydrophobicity and alterations in surface groups. Their adsorption rate first decreased and then stabilized as the number of cycles increased and was as high as 81.76% after 25 cycles. Correlation analysis revealed that the adsorption efficiency of regenerated nanofiber mats was related to their microstructure, surface groups and hydrophobicity. These findings could provide a theoretical basis for odor removal by electrospun nanofiber mats and their recycling. [Display omitted] • Nanofiber mat maintained a good morphology after thermal regeneration for 25 cycles. • Adsorption of fiber mat showed first decreased then stabilized as cycles increased. • Adsorption efficiency of mat was related to its microstructure and surface groups. • Adsorption of mat for alcohols was negatively correlated with its hydrophobicity. [ABSTRACT FROM AUTHOR]

The role of amylose content in electrospinning starch nanofibres is well understood, but that is not the case for the roles of the molecular structures of amylose and amylopectin. Here, correlations between starch molecular-structure parameters and electrospinnability evaluation indices (average droplet number, average bead number, and average fibre diameter) and dope properties (shear viscosity, conductivity, and surface tension) were examined. Starches with lower amounts of short amylopectin chains, higher amounts of either/or long amylopectin chains and/or lower degree of branching showed decreased viscosity of the electrospinning dopes, and resulted in a reduced average droplet number of electrospun fibre mats. The molecular sizes of amylose and whole starch, and the average degree of polymerization for amylose chains, all correlated with the shear viscosity and surface tension of dopes, and thus influenced the average fibre diameter. This expands the current understanding between amylopectin molecular structure and starch electrospinning, thereby assisting a better choice of starches for desired electrospinnability properties. [Display omitted] [ABSTRACT FROM AUTHOR]