Structural Characteristics of Eleusine Corocana (Finger Millet) Using Scanning Electron and Fluorescence Microscopy

Abstract

The objective of this study was to document the microstructure of finger millet wlth scanning electron and fluorescence microscopies. Finger millet is an utricle which is spheri ca 1 and about 1 . 5 ITlT1 in diameter. The membranous peri carp of finger millet was loosely associated with the seed at maturity. Beneath the loose pericarp wa s a five-layered testa that varied from red to purple in color. The outer layer was the only testa layer that autofl uoresced, suggesting the presence of phenolic acids, i .e., ferulic acid. The aleurone layer was beneath the testa , and was one cell layer thick. The starchy endosperm had distinct peripheral, corneous and floury areas. The ce 11 wa 11 s of the endosperm strongly fl uoresced indicat ing phenolic compounds . Starch granules were primarily compound, with some simple granules in the corneous area . Starch granule size increased toward the center of the endosperm, while the protein content decreased. The small germ was inset into a shallow depression; a short ridge protruded from the utricle around the perimeter of t he germ. Finger milllet was higher in phenol and tannin content than pearl millet . Moderate levels of gentisic , cinnamic and coumaric acids , and high levels of ferulic acid we reextracted from finger millet.