Cereal Chem 49:324 - 335.  |  VIEW ARTICLE
Wheat-Grain Morphology and Its Relationship to Dough Structure.

D. H. Simmonds. Copyright 1972 by the American Association of Cereal Chemists, Inc. 

Mature wheat endosperm cells contain remnants of endoplasmic reticulum, amyloplast membranes, and other cell organelles which contribute extensively to flour lipids. During dough-mixing and gluten formation, these remnants form intensely osmiophilic inclusions which may be observed under the electron microscope. Such organelle residues are insoluble in urea solutions. On addition of water they also give rise to free lipid which interacts with protein to form an additional urea-insoluble lipoprotein fraction. Under the electron microscope, this fraction appears as osmiophilic vesicles of various types and sizes. It is postulated that these vesicles are derived from an extensive lipoprotein network originally present in fresh gluten and dough.