Wheat gluten as a protein ingredient

Wheat gluten is a unique cereal protein due to its property of high elasticity. This elasticity is only present in hydrated gluten, and it is destroyed by heating. The property permits the formation of gas cells in flour dough, and is the essential cause of the texture of our daily bread. Wheat gluten is produced industrially from flour rather than from wheat, although some progress has been made recently in the latter direct process. All the wet separation methods basically involve mixing flour and water and allowing the starch granules to leave the gluten matrix in a mixed aqueous phase. The various methods of wet separation give rise to essentially similar glutens, but the type and severity of the drying process can lead to major changes in degree of elasticity of the reconstituted gluten. In spite of a rather low level of lysine, methionine and tryptophane, the nutritive value of wheat gluten can be high, particularly when mixed with other proteins which supplement these particular amino acids. Although gluten can be used alose, as in some canned vegetarian dishes, generally it is used as an additive to cereal and meat or fish foods. In cereal applications the base material is usually flour or maize, rice or wheat. The market for gluten in the Western World is of the order of 90,000 tons per year, and it is expected that the industrial use of wheat gluten will continue to expand with our technical ability to make use of its unique properties.