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.