Cereal Chem 47:236 - 243.  |  VIEW ARTICLE
Electron Microscopy of Endosperm Protein from Hard and Soft Wheats.

H. L. Seckinger and M. J. Wolf. Copyright 1970 by the American Association of Cereal Chemists, Inc. 

Protein either in flour particles or in thin sections spreads on water as a surface dispersion. These protein dispersions were transferred to plastic-covered specimen grids and examined by transmission electron microscopy. Examinations showed that wheat flour contained lipid which formed small droplets ranging from 0.01 to 0.35 micron in diameter. Protein bodies like those found in immature wheat were not observed in any of the preparations. A purified fraction of gliadin contained particles 20 and 80 A in diameter, representing molecular weights between 17,000 and 216,000; whereas a glutenin fraction did not form small particles. Protein dispersions from hard and soft wheat had particles 65 to 250 A in diameter; hard wheat had smaller particles than the soft wheat. Mild treatment with NaHSO3 increased the size of hard wheat protein particles; those in soft wheat did not change much. From these observations, hard wheat appears to have compact protein particles which swell in NaHSO3 whereas the structure of soft wheat particles is less dense and they swell in distilled water.