Flour treatment agents (also called improving agents, bread improvers, dough conditioners and dough improvers) are food additives combined with flour to improve baking functionality. Flour treatment agents are used to increase the speed of dough rising and to improve the strength and workability of the dough. They are an important component of modern plant baking, reducing the time needed to produce a loaf of bread to two hours from the 12 to 24 hours early bread-making required. There are wide ranges of these conditioners used in bakery processing, which fall into four main categories: bleaching agents, oxidizing and reducing agents, enzymes, and emulsifiers. These agents are often sold as mixtures in a soy flour base, as only small amounts are required.
Flour bleaching agents are added to flour to make it appear whiter (freshly milled flour is yellowish), to oxidize the surfaces of the flour grains, and help with developing of gluten.
Oxidizing agents are added to flour to help with gluten development. They may or may not also act as bleaching agents. Originally flour was naturally aged through exposure to the atmosphere. Oxidizing agents primarily affect sulphur containing amino acids that ultimately help form a disulphide bridge between gluten molecules. The addition of these agents to flour will create a stronger dough.
Common oxidizing agents are:
- various flour bleaching agents
- azodicarbonamide (E927)
- carbamide (E927b)
- potassium bromate (E924, the component which gives bromated flour its name, used mainly in the midwest and east of the US, acts as a bleaching agent, banned in some areas)
- ascorbic acid (used mainly in the western US, helps form gluten)
- malted barley
- potassium iodate
Reducing agents help to weaken the flour by breaking the protein network. This will help with various aspects of handling a strong dough. The benefits of adding these agents are reduced mixing time, reduced dough elasticity, reduced proofing time, and improved machinability.
Common reducing agents are:
- L-cysteine (E920, E921; quantities in the tens of ppm range help soften the dough and thus reduce processing time)
- fumeric acid
- sodium bisulphate
- non-leavened yeast
- ascorbic acid
Enzymes are also used to improve processing characteristics. Yeast naturally produces both amylases and proteinases, but additional quantities may be added to produce faster and more complete reactions.
- Amylases break down the starch in flours into simple sugars, thereby letting yeast ferment quickly. Malt is a natural source of amylase.
- Proteases improve extensibility of the dough by degrading some of the gluten.
- Lipoxygenases oxidize the flour.