Development of electrospun whey protein isolate nanofiber mat for omega-3 nanoencapsulation: Microstructural and...

This study aimed to develop bead-free nanofibers for effective omega-3 encapsulation using optimal mixing ratios of whey protein isolate (WPI)/polyvinyl alcohol (PVA) blends via electrospinning method. Various WPI-PVA ratios (100:0, 90:10, 80:20, 70:30, 60:40, 50:50 v/v) were examined for surface tension, viscosity, and conductivity. SEM images revealed uneven nanofibers with bead at 90:10 and 80:20 ratios, while the 70:30 ratio produced uniform and bead-free nanofibers with an average diameter of 262.7 ± 49.5 nm. Other ratios exhibited uneven diameters. Therefore, the 70:30 ratio was chosen to encapsulate omega-3 at 6 %, 8 %, and 10 % v/v concentrations. SEM analysis showed that omega-3, at the optimal concentration of 8 %, was successfully loaded into the nanofibers, as shown by the highest encapsulation efficiency and the formation of beadless nanofibers in SEM images. FTIR spectra confirmed an interaction between polymers and revealed the effective inclusion of omega-3 within the nanofibers. XRD indicated a shift from semi-crystalline to an amorphous structure. In conclusion, the bead-free nanofibers demonstrate the highest encapsulation efficiency of omega-3. TGA results showed significant improvement in the thermal stability of omega-3 after nanoencapsulation in nanofibers. These new electrospun nanofibers have the potential to encapsulate bioactive compounds used in functional food products.