Commercial Baking Processes

White bread still accounts for the majority of bread eaten in the whole world. Different methods are used for developing the dough, including yeast fermentation, mechanical development, and chemical development.

Yeast Fermentation

Yeast fermentation involves mixing flour, water, yeast, fat, and salt to produce the dough, which is then fermented at 27^oC prior to baking. The two common methods include the:

1. Sponge and dough system, which involves fermenting only a part of the flour with yeast and water to produce a spongelike dough. After mixing, the remainder of the flour, water, salt, fat, etc., is added to the dough for a short fermentation period before proofing and baking.

2. Straight dough system, in which all the ingredients are mixed prior to fermentation.

Bread produced by the sponge and dough system has good loaf volume, fine grain and texture, and fuller flavor. The major disadvantages of this method are the high costs of production and equipment involved in a process, which takes 7 to 8 hr to complete.

Although both amylolytic and proteolytic enzymes are naturally occurring in the flour, it is common practice in the bakery to supplement their activity by adding enzymes derived from fungi such as species of Aspergillus oryzae.

Amylase supplementation increases the availability of sugars that can be fermented by yeast, which in turn helps to sustain yeast growth and fermentation. It also lowers the dough viscosity, resulting in a bread with a softer crumb and with improved storage qualities.

Protease supplementation releases amino acids and peptides that are required for yeast growth, and also enhances the texture and elasticity of the gluten. Both the amylases and proteases enable the dough to be handled more easily by hand or machine, and also increase dough volume.

Biochemistry of Bread Baking

Bread Index