Flour, eggs, water, fat, and usually sugar are necessary in all baking and pastry goods. The ways in which these ingredients interact with one another and other ingredients during mixing and baking dictate the qualities of the end product. For the purposes of understanding how these ingredients influence a finished product, they can be divided into two categories: stabilizers and liquefiers.
Proteins in Flour
Gluten is formed by the proteins present in wheat flour (wheat is the only grain that forms measurable amounts of gluten, making it an indispensable grain in the kitchen or bakeshop). Flour gives strength to a batter or dough and acts to absorb the bulk of the moisture in most baked goods. As the flour takes up water, gluten strands begin to form. To further develop these strands, making them more cohesive and elastic, the mixture is agitated (mixed).
Gluten development is essential for certain baked goods such as breads, in which a somewhat chewy texture is desirable; in other baked goods such as cakes, which should be tender and moist, excessive gluten development is a flaw. The differences among desired outcomes for the textures of different types of baked goods led to the development of flours with varying gluten levels.
While the gluten level of the flour has a very significant role in the final texture of a product, the amount of mixing a dough or batter undergoes, particularly if the flour has a moderate to high percentage of gluten, will also have a marked impact.
Gluten is composed of two distinct proteins: glutenin and gliadin. When flour is mixed with water, the glutenin and gliadin begin to join together (with the water intermingled) to form strands or sheets of gluten. The glutenin provides the elasticity; the gliadin, the extensibility. The formation of these strands provides the structure for many baked goods. If a flour with too little (or no) gluten is used in bread making, the bread will not rise. Yeast is the catalyst for risen bread, but it is also necessary to have well-developed gluten to trap the gases produced by the fermenting yeast for bread to rise.
