Flour bleaching agent

Flour bleaching agent is a food additive added to flour in order to make it appear whiter (freshly milled flour has a yellowish tint) and to oxidize the surfaces of the flour grains and help with developing of gluten.

Usual bleaching agents are:

• Organic peroxides, namely benzoyl peroxide
• Calcium peroxide
• Nitrogen dioxide
• Chlorine
• Chlorine dioxide
• Azodicarbonamide
• Atmospheric oxygen, used during natural aging of flour

Use of chlorine, bromates, and peroxides is not allowed in the European Union.

Flours treated with bleaches and improving agents generally show higher loaf volume and finer grain. However, people with very sensitive palates can detect a slight bitter aftertaste.

Chlorinated cake flour improves the structure forming capacity, allowing the use of dough formulas with lower proportions of flour and higher proportions of sugar. In biscuit manufacturing, chlorination of flour is used to control the spread – treated flour reduces the spread and provides a tighter surface. The changes of functional properties of the flour proteins are likely to be caused by their oxidation.

In countries where bleached flour is prohibited, plain flour can be treated in a domestic microwave oven to produce similar chemical changes to the bleaching process. This improves the final texture of baked goods made to recipes intended for bleached flours.

There is a misconception that alloxan, a destroyer of beta cells in the pancreas, is used to bleach flour. Though the process of bleaching flour can produce trace amounts of alloxan, it has never been proved to be a problem or to build up in the body.

See also

• Chorleywood bread process, another bread making process that increases volume
• Flour treatment agents
• Graham flour, an early unbleached and whole grain flour
• Maida flour, a commonly bleached flour in India