Cereal Chem 63:336-341   |  VIEW ARTICLE
Structure and Function of Gluten Proteins.

H.-D. Belitz, R. Kieffer, W. Seilmeier, and H. Wie ser. Copyright 1986 by the American Association of Cereal Chemists, Inc. 

Proteins contribute to the nutritional value of foodstuffs, as well as to their physical properties, by forming and stabilizing gels, foams, emulsions, fibers, and doughs. The relations between structural and functional properties are illustrated by examples taken from the cereal proteins. The special position of wheat among the cereals comes from its capability to form gluten by interaction between the less polar prolamins and the more polar glutelins. The rheological properties of gluten are influenced by the proportion of prolamins to glutelins and by the hydrophobicity of the prolamins. Within the glutelin fractions, the very high-molecular, glycine-rich components are of particular importance. High amounts of these proteins are typical of wheat varieties with good baking properties. These high-molecular components are built up of subunits, probably via disulfide bridges, during dough mixing in the presence of oxygen. In the course of a stepwise reduction of the glutelin disulfide bonds, prolamin-like components are liberated first, whereas the components rich in glycine and most most characteristic for glutelin remain in a highly aggregated state until the reduction is more complete. Besides disulfide bonds, ionic bonds seem to be of great importance to gluten structure, because rheological properties may be changed very strongly by addition of low-molecular-weight divalent ions. These facts are discussed in connection with different gluten models.