A protein is a polymer of amino acids linked together by peptide bonds. There are approximately twenty amino acids that constitute the backbone of proteins. Commercial sources of protein include those derived from milk, eggs, oilseed (soy), pulses (pea), and grains (wheat, corn). In the case of wheat, protein contains high levels of glutamine followed by proline and leucine. Wheat (gluten) proteins are considered unique because of its ability to form a viscoelastic dough when mixed with water. The viscoelasticity is attributed to a proper balance of gliadin and glutenin, the two major fractions that make up wheat gluten. Gliadin is responsible for cohesiveness and extensibility of hydrated gluten and glutenin imparts elasticity. Wheat gluten is the only naturally-occurring protein that exhibits this unique property.