How does wheat flour become malleable and elastic when mixed with water?

 Basically wheat flour does not contain any malleable or elastic characteristic materials. When water is added to wheat flour, a new product called Gluten is formed by hydration of wheat proteins. It causes the production of dough. Gluten contains water approximately 2/3rd of its weight. It forms about 90 per cent of the total protein of flour. It is stretchable product just like rubber. It also contains small quantity of fat, cellulose and minerals.

 Gluten in turn contains protein fragments called Glutenin and Gliadin. These two confer the dough the elastic and malleable properties. When mixed together, as they are in dough, these two proteins form a tangle of strands that trap the gas. While gliadin in gluten confers mellowness and elasticity, the glutenin provides the structure. Greater the amount of gliadin, softer will be the gluten. Gluten is responsible for the rheological properties of dough because it forms the skeleton of the dough. High structured products like bread and bun require stronger quality of gluten while low structured products like biscuits and cakes do not require strong gluten. Courtesy : The Hindu