Cereal Chem 51:173 - 179.  |  VIEW ARTICLE
Modified Opaque-2 Corn Endosperms. II. Structure Viewed with a Scanning Electron Microscope.

J. L. Robutti, R. C. Hoseney, and C. E. Wassom. Copyright 1974 by the American Association of Cereal Chemists, Inc. 

Scanning electron micrographs of soft endosperms from normal, opaque-2, or modified opaque-2 corn showed loosely packed, nearly round starch granules associated with thin sheets of protein and many intergranular air spaces. The hard endosperms had tightly packed, polygonal starch granules associated with a continuous protein matrix, and no intergranular air spaces. Normal hard endosperms had zein bodies embedded in the protein matrix; modified hard endosperms did not. Starch damage was greater in the hard endosperm than in soft because of a stronger adhesion between starch and protein. The low density and opaqueness of soft endosperm were attributed to the intergranular air spaces. Interaction between protein matrix and starch granules during drying explains the shape of starch granules.