About this Research Topic
With the advent of nanotechnology, nanofibers have assumed increasing importance in the scientific community and currently electrospinning is the easiest method to fabricate uniform nanofibers. Electrospinning is an electrohydrodynamic process that elongates polymers into fibers with different range of diameters using electrical power.
A typical laboratory scale electrospinning set up only consists of syringe with metal capillary as the spinneret, syringe pump, target electrode as the collector and high voltage power supply. Hence, electrospinning is a relatively simple and direct approach as compared to conventional drawing process for the fabrication of fibers. The common electrospinning techniques that have been reported up to now are blend, co-axial, melt, emulsion, multi-jet and needless electrospinning, where solution, processing and ambient parameters have effects on the output of the process.
In the food industry, electrospinning technology has the potential of evolving from its current narrow application to broader and more universal usage. Electrospinning can be used to produce polymer composite fibers by blending components such as active compounds, plant extracts, particles or enzymes to achieve desired properties. The fabricated electrospun fiber mats can also serve as a supporting structure for loading of active compounds through physical adsorption, chemical immobilization or layer-by-layer assembly. Through creative exploration of selective polymers and polymeric assemblages, this technique could offer a versatile multidimensional approach to improve food and agricultural product quality (sensorial characteristics, novel additive), nutrition (nutrient absorption and delivery), and food safety (food packaging and contact materials).
Its applications can be directed in food processing, as new food coating, food packaging materials and biosensor, filtration membrane, and smart encapsulation carrier or vehicle. For instance, the produced fiber mats generally display properties such as high porosity and permeability, large-surface-area to volume ratios, light weight, flexibility in fiber alignment, diameter, thickness as well as surface functionalities. Hence, the highly porous electrospun nanofiber mats meet perfectly the anticipated necessities for ultrasensitive sensor as they exhibit large surface area, which have offered potentials to construct efficient interfaces with molecular electronic properties.
Additionally, electrospun fibers are found to be capable of improving the dissolution rate of poorly water soluble components, through provision of huge surface area for the active compound to be in contact with the dissolution media and fast wetting properties. All of these structural and functional advantages enable the fabricated electrospun fiber mat promising tools to assist regulators for health or food safety controls and nutrient enhancement.
Nevertheless, the utilization of electrospinning for food application is still in its infancy despite electrospun fibers may offer many prospects and opportunities for innovative exciting properties. One of the possible causes that has impeded the progress is its low production rate that limited its usage for large production of nanofibers. The lack of knowledge of the selection of electrospinnable Generally Regarded as Safe (GRAS) polymers makes the assessment based on empirical ground, and most of the studies available have been conducted using organic solvents and non-food grade polymers that are less favorable in food. Polymeric nature of electrospun fibers also restricts this technology for low concentration solutions. There is limited number of commercially available electrospun products in the market that are largely developed by industries for food applications. This might be due to lack of awareness of the potential of electrospinning in food industry.
Electrospun nanofibers would be regulated as nanostructured material, for which a mature and well-established regulatory framework has not yet occurred. The results of a 2015 overview of nanomaterials regulatory measures suggested that EU and Switzerland were the only world region where nano-specific provisions have been incorporated in existing food legislation. Overall, primary concern about the safe use of nanotechnology in food applications is commonly on the knowledge gaps (lack of toxicological/ecotoxilogical data, toxicity thresholds, hazard identification), where the current testing schemes may not be adequate to address all matters arising with nanostructured materials.
To date, various aspects of electrospinning technology such as fabrication, properties and functioning of electrospun fibers have been reported, and the outcomes are generally favorable for intended food applications. Yet, public views on the application of electrospinning technologies in the food industry should also be highlighted to avoid future business pitfalls. Aiming to eliminate the limitations come upon by electrospinning technology, experts involving multidisciplinary (material science, chemist, engineer, nutritionist, food scientist etc.) are welcomed to explore and translate their expertise to practical applications of electrospinning in food. All scientists are invited to contribute either review or research articles that highlight the opportunities, challenges, regulatory aspects and possible strategies required to sustain electrospinning technology in food industry.
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