Explain Dough Formation
Gluten is the protein found in wheat. A unique property of gluten proteins of wheat grain endosperm (and to a lesser extent of rye and barley grains) is their ability to form a strongly cohesive and viscoelastic mass or dough, when mixed and kneaded in presence of water at ambient temperature. In addition to glutens (gliadin and glutenins), wheat flour contains starch granules, pentosans, polar and non polar lipids and soluble proteins, all of which contribute to the formation of dough network and/or the final texture of bread.
Composition and large size of gliadins and glutenins explain much of the behaviour of gluten. Due to their low content of ionizable amino acids, the gluten proteins are poorly soluble in neutral aqueous solutions. Rich in glutamine (>33% by wt.) and in hydroxy amino acids, they are prone to hydrogen bonding which accounts largely for water absorbing capacity and for the cohesion and adhesion properties of gluten. Latter properties also derive in part from the presence of many apolar amino acids and the resulting hydrophobic interactions that contribute to protein aggregation and binding of lipids and glycoproteins. Finally, the ability of forming numerous -S-S- cross linkages accounts for the ease with which these proteins interlink tenaciously in dough.