Gluten is a set of proteins that are naturally found in certain grains (wheat, rye, barley, spelt). Gluten creates the elasticity and structure of derived grain products. For instance, in bread the gluten network will retain the fermentation gasses and give the volume to the bread. Wheat flour, the main ingredient in pasta, bread and pastry products, contains gluten. Gluten protein can also be added to all kinds of foods to affect the texture (texturing agent).