Baking and Pastry: Formation of Dough

Physical Changes During Dough Formation

• Flour components, primarily starch and protein, are hydrated when they come into contact with water.
• There are two main types of starch: native starch, which absorbs water on the outside of the particle, and damaged starch, which absorbs close to its own weight in water.
• Both native and damaged starch act as filling agents in a dough system.
• The two primary proteins in wheat, glutenin and gliadin, are responsible for dough formation and can absorb 200-250% of their weight in water.
• Glutenin affects the elasticity of the dough, while gliadin affects its extensibility.
• When glutenin and gliadin proteins absorb water, they inflate and become attracted to each other, forming chains of proteins called gluten.

Gluten Development

• The mechanical operation of the dough hook works the gluten into an organized structure through two distinct movements: stretching and folding.
• This process creates a three-dimensional gluten structure, with longer, finer, and more overlapped chains of gluten.
• A longer mix generates a well-developed gluten structure, while a shorter mix generates an underdeveloped one.
• Overmixing can break the gluten chains, leading to a weaker gluten structure.

Chemical Changes During Dough Formation

• Two main natural chemical reactions occur during mixing: fermentation activity and enzyme activity.
• The rate of these reactions depends on the quantity of water used.
• Wet dough generates faster fermentation activity, which may require reducing the level of yeast needed in the formula.
• Oxidation occurs during mixing, incorporating oxygen into the dough and affecting gluten bonds and pigments.
• Too much oxygen can lead to a whiter crumb color and a blander flavor, while some oxygen is necessary for better gluten bonds and tolerance.

Oxidation and Its Effects

• Overmixing can lead to too much oxygen incorporation, negatively affecting carotenoid pigments and resulting in a whiter crumb color and a blander flavor.
• Salt can be used to slow down chemical reactions, including oxidation, and minimize its negative effects.
• Incorporating salt at the beginning of mixing can retard oxidation, while delaying salt incorporation can lead to a whiter crumb structure but at the expense of flavor.