Fig. 4: Characterization of fiber composition using scanning electron microscopy (SEM).

a SEM images of cross-section and surface of alginate (A) and zein-coated alginate (ZA) fibers. Scale bars = 100 and 50 μm for cross-section and surface images, respectively. b SEM image of internal alginate fiber and zein-coated shell. Scale bars = 100 μm (cross-sections) and 50 μm (surface).