Gluten in wheat

Gluten is a storage protein found in several grains such as wheat, barley and rye.

Wheat gluten is the water insoluble complex protein fraction separated from wheat flours.

It is primarily a mixture of two types of protein from the wheat kernel glutenin and gliadin.

Gluten helps hold things together. It gives elasticity to dough and will help it rise and maintain its shape. It gives bread its structure and chewiness.

Wheat gluten is a protein-lipid-carbohydrate complex, formed when flour is hydrated: when the starch is washed away with more water, the gluten coheres as an elastic, insoluble, rubber like mass, which can be dried to give a cream colored powder.

Gliadin is the fragment of the gluten-chain that can’t be digested by those with celiac disease or non-celiac gluten-intolerance.

As a natural source of protein, gluten is commonly used as an additive on foodstuffs with a low protein value and it’s also used in a variety of hair and skin care product.
Gluten in wheat

Gliadin in wheat flour

Gliadin is a heterogeneous group of prolamines. They are rather hydrophobic, hence their insolubility in water or salt solutions. They are single chain proteins and such disulfide bonds that occur are all intra-molecular. 

Gliadin is the major storage protein in wheat. Wheat flour has a total protein content of about 10% and approximately 10% of these proteins are made up of alcohol soluble gliadin proteins.

Gliadin is practically as abundant in the wheat kernel. The proportion of gliadin in wheat flour has much to do with its quality for bread making purpose. It is said that gliadin gives tenacity and elasticity to the gluten, while glutenin gives strength; but the two proteins must be present in proper protein of the gluten is to have the properties desired in bread-making.

In order to make a large light loaf of bread, the flour should have a fairly high gluten content and its gluten should contain a high proportion of gliadin.
Gliadin in wheat flour