Fabrication of alkali lignin-based emulsion electrospun nanofibers for the nanoencapsulation of beta-carotene and the enhanced antioxidant property

For the greater utilization of β -carotene in antioxidant material, β -carotene-loaded emulsion stabilized by alkali lignin (AL) was successfully electrospinning with poly (vinyl alcohol) (PVA) (PVA/AL/ β -carotene nanofiber). Transmission electron microscopy demonstrated the core-shell structure of nanofiber with the average diameter being 356.31 nm, and 85.7 % of β -carotene was effectively encapsulated into the core section. Fourier transform infrared spectra and differential scanning calorimetry revealed the good compatibility and decreased crystallinity of β -carotene, favoring its stability and solubility, respectively. As expected, the PVA/AL/ β -carotene nanofiber exhibited higher antioxidant activity than free β -carotene due to the protection of AL matrix and the special structure of nanofiber, as the DPPH free radical scavenging rate being 90.7 % at 7th day. The sustained release behavior of β -carotene and AL from fiber followed Fickian diffusion model, contributing to the greater protection for fish oil than that of emulsion. Thus, this study provides an approach to develop hydrophobic compounds-loaded emulsion electrospun antioxidant material with controlled release property and enhanced activity.