Flour bleaching agent

Flour bleaching agent is a food additive added to flour in order to make it appear whiter (freshly milled flour is yellowish) 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, which is reported to produce diabetes-causing contaminant alloxan when reacting with the proteins contained in flour
 * 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.