Submicroscopic Structure of the Cereal Starch Grain

The submicroscopic structure of the starch grains of Zea maysand Triticum sativum was studied electron-optically from replicasmade of internal, fracture surfaces. In corn starch, long cylindricalmicrofibrils were found, arranged in a radial direction andimbedded in an amorphous matrix. Their diameter was uniformlyabout 200 Å. Microfibrils were also indicated in wheatstarch because of the prominence of their ends in surface view.Many microfibrils in corn starch appeared to be helically coiled.The more ordered starch substance was presumed to be localizedprincipally in the microfibrils.