Gluten is a kind of protein found in wheat, barley and rye. It is elastic, so it can give pasta a chewy taste. Gluten is a complex of two storage proteins, gliadin and glutenin. These two kinds of protein combine with the starch in the endosperm. Gluten contains hundreds of protein, but its biological value (digestibility and availability of protein) is very low. The biological value of white flour is only 5 1, while eggs are 94, milk is 82, beef is 73 and white rice is 6 1. For some people, gluten can cause some adverse reactions. These adverse reactions are collectively referred to as gluten-related disorders.
Gluten mainly exists in wheat, rye and barley and their hybrid varieties. All kinds of foods produced and processed from these cereals, such as bread, cakes, biscuits and beer, generally contain gluten. Gluten is a mixture of a series of protein, which consists of about 50% prolamine and about 50% glutenin, among which prolamine is the chief culprit of human allergy. Glutenin is called gluten in wheat, rye essence in rye and barley gliadin in barley.