Wheat endosperm development has been studied in numerous laboratories. The genera 1 i zed scheme of protein body formation assembled from these data indicates that storage proteins are initially formed in the rough endoplasmic reticulum (RER). The storage proteins in RER may be processed via the Golgi apparatus into vesicles that enlarge by several mechanisms into membrane-bounded protein bodies. The prote in bodies are transported through the cytoplasm to the vacuole where they fuse with the tonoplast and deposit the protein granules into the vacuoles. The protein granules fuse with one another, lose water, and eventually become transformed into the matrix. The starchy endosperm is reduced to small particles of starch and protein during milling. These flour particles are dynamically rehydrated during dough formation. The protein forms the major structural network surrounding starch granules in doughs. The framework of bread crumb, however, is of dual composition; the protein network and a newly formed network of gelatinized starch.
Bechtel, D, B.
"The Microstructure of Wheat: Its Development and Conversion Into Bread,"
Food Structure: Vol. 4
, Article 15.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol4/iss1/15