Gluten is a protein that is present in the endosperm of cereal grains viz. Wheat, barley and rye and is not found in the young grasses that sprout from its seed.
It is composed of two different proteins: gliadin and glutenin. Gliadin is responsible for elasticity whereas glutenin gives toughness to the gluten. The two proteins (gliadin and glutenin) when combined in the presence of water along with mechanical action form a tough elastic complex known as Gluten.
True Gluten is sometimes referred to as being specific to Wheat, gluten is often considered to be a part of other cereal grains like rye, barley, triticale (hybrid cereal obtained from a cross breed between wheat and rye).
Gluten is present in a wide variety of processed foods that we consume daily like pizza, pasta, cakes, muffins, pastry, chips etc. Gluten helps with the rising of bread and other baked products while also adding to the texture and chewiness. The elastic nature of the gluten makes it possible for it to be easily rolled into chapatti. It can also be used as a thickener, binder, stabilizer, flavour enhancer and protein supplement.
It is often present as a hidden source in beer, soy sauce, ketchup, ice cream and many other food products.
It is also used in shampoos, cosmetics and other dermatological preparations.