Flour treatment agent
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. While they are an important component of modern factory baking, some small-scale bakers reject them in favour of longer fermentation periods that produce greater depth of flavour. There are wide ranges of these conditioners used in factory baking, 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.
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 sulfur-containing amino acids, ultimately helping to form disulfide bridges between the gluten molecules. The addition of these agents to flour will create a stronger dough.
Common oxidizing agents are:
- ascorbic acid (Ascorbic acid converts into its oxidizing form, dehydroascorbic acid (DHAA) during mixing.)
- azodicarbonamide (E927)
- potassium bromate (E924, the component which gives bromated flour its name, used mainly in the U.S. East and Midwest, acts as a bleaching agent, banned in some areas)
- 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)
- fumaric acid
- sodium bisulfite
- non-leavening yeast (ruptured cells)
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.
Other additives may be used as yeast nutrients or as a source of enzymes:
- Hui Y and Cork H (2006). Bakery products: science and technology. Blackwell Publishing.