摘要
Spirulina is a microalga that is well-known for its high protein content and biological activities directly related to its antioxidant capacity.The objective of this study was to produce fast-dissolving antioxidant nanofibers based on Spirulina protein concentrate (SPC) and gelatin using needleless electrospinning technique.The effect of mixing ratios of SPC (10% w/w) and gelatin (20% w/w) on the viscosity,electrical conductivity and surface tension of electrospinning solutions as well as diameter and morphology of resulting nanofibers was investigated.Increasing the SPC level in the solution blends resulted in a decrease in apparent viscosity and electrical conductivity and an almost stable trend in surface tension (29.25–32.19 mN/m) that led to diminish of diameter of the nanofibers.Scanning electron microscopy images showed that SPC/gelatin ratio of 40:60 led to the production of uniform and bead-free nanofibers with a relatively smaller average diameter (208.7 ± 46.5 nm).Atomic force microscopy images indicated mesh-like,fibrillary,and bead-free structures.Fourier transform infrared spectroscopy verified the formation of composite nanofibers and intermolecular interactions between both proteins.X-ray diffraction and thermal analysis showed higher amorphous structure and stability of produced SPC/gelatin nanofibers in comparison to pure materials which was favorable for formation of stable fast-dissolving fibers.Results of DPPH and ABTS radical scavenging activities showed that the antioxidant activity of composite nanofibers significantly improved with increasing SPC mixing ratio (p < 0.05).The dissolution test demonstrated that SPC/gelatin nanofibers can be rapidly dissolved in aqueous medium within 2 s.Finally,the results indicated that the electrospun SPC/gelatin nanofibers could be potentially used for nutraceutical delivery in food and packaging applications under high humidity.
