A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to breaddough to strengthen its texture or otherwise improve it in some way. Dough conditioners may include enzymes, yeast nutrients, mineral salts, oxidants and reductants, bleaching agents and emulsifiers.[1] They 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.
Less processed dough conditioners include sprouted- or malted-grain flours, soy, milk, wheat germ, eggs, potatoes, gluten, yeast, and extra kneading. Malted, diastatic flours are not typically added by manufacturers to whole-wheat flours.
History
In the early 1900s it was discovered the use of calcium chloride, ammonium sulfate, and potassium bromate halved the amount of yeast needed to raise dough. These mixtures were generally known as mineral yeast foods or yeast nutrient salts. After they became popular among bakers, one patented yeast food was analyzed by Connecticut Agricultural Experiment Station chief chemist J.P. Street who published in 1917 that it contained, "calcium sulphate, 25; ammonium chlorid, 9.7; potassium bromate, 0.3; sodium chlorid, 25; patent wheat flour, 40."[8] They contain water conditioners, yeast conditioners, and dough conditioners.[9]
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.[19]Dehydroascorbic acid and potassium bromate are oxidants, acting on sulfhydryl groups and disulfide bonds in wheat dough, in particular oxidizing glutathione. Potassium bromate acts more directly or with fewer chemical conversion steps than ascorbic acid. Glutathione increases wheat dough's extensibility, or relaxes it, while oxidizing a dough's glutathione increases elasticity. Common oxidizing agents are:
ascorbic acid[20] (Ascorbic acid converts into its oxidizing form, dehydroascorbic acid (DHAA) during mixing.)
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)
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.[19]Cysteine and bisulfite[note 1] are reducing agents which relax wheat dough.[22][23] Adding minute amounts of oxidants or reducing agents alter the post-mix handling characteristics of dough.[24][25][26][27] Common reducing agents are:
L-cysteine (E920, E921; quantities in the tens of ppm range help soften the dough and thus reduce processing time)
Lecithin, monoglycerides, diglycerides, and DATEM are considered emulsifiers. They disperse fat more evenly throughout the dough, helping it to trap more of the CO2 produced by yeast.[29] Lecithin added at a rate of 0.25-to-0.6% of the flour weight acts as a dough conditioner.[30] Based on total weight, egg yolk contains about 9% lecithin.[31] Monoglycerides and diglycerides replace eggs in baked goods.[32] Emulsifiers tend to produce a finer grain, softer crumb, and with longer proof times, increased baked volume and have antistaling effects.[33][7]
Enzymes
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.
^Ravi, R.; Manohar, R.; Rao, P. (2000). "Influence of additives on the rheological characteristics and baking quality of wheat flours". European Food Research and Technology. 210 (3): 202–208. doi:10.1007/PL00005512. S2CID84732563.
^Clyde E. Stauffer (1990). Functional Additives for Bakery Foods. Van Nostrand Reinhold. p. 8. ISBN978-0442003531. LCCN90-37356. Azodicarbonamide is frequently added to bread flour at the mill [in one-third of the cases in the survey done by Kulp (1981) referred to earlier]. Potassium bromate was added to 19% of the flours, and ascorbic acid to one (out of 63). This is done as a convenience for the bakery customer, who specifies the level of addition to obtain the best performance on the production line without having to add more oxidant in the plant. In the United States the maximum level of addition to flour is 45 ppm for ADA, 75 ppm for potassium bromate, and 200 ppm for ascorbic acid, although more typical dosing levels are 10 ppm, 25 ppm, and 50 ppm, respectively. Certain other materials may be also added at the mill, notably a-amylase (as malted barley powder or fungal enzyme) and vitamin enrichment to meet FDA standards for enriched flour....
^Dennis E. Briggs; Chris A. Boulton; Peter A. Brookes; Roger Stevens (2004). "12.3". Brewing Science and practice. Cambridge, England: Woodhead Publishing Limited. ISBN978-1-85573-490-6.
^Pearce, E.N.; Pino, S.; He, X.; Bazrafshan, H.R.; Lee, S.L.; Braverman, L.E. (2004). "Sources of dietary iodine: bread, cows' milk, and infant formula in the Boston area". The Journal of Clinical Endocrinology & Metabolism. 89 (7): 3421–3424. doi:10.1210/jc.2003-032002. PMID15240625. Conditioners are added to store-bought bread to maintain freshness and prolong shelf life. In the 1960s, iodate bread conditioners were widely used. London et al. (13), in 1965, reported that bread was a source of large quantities of dietary iodine, with iodine content as high as 150 μg per slice. This was considered to be a contributing cause to the decreasing radioactive iodine uptake in the U.S. during the 1960s (14, 15). Because of the concerns about high bread iodine content, commercial bakeries now less commonly use iodate bread conditioners. The decreasing use of iodate bread conditioners is thought to have contributed to the reduction in dietary iodine levels between the 1970s and the early 1990s.
^Manley, Duncan (2000). Technology of Biscuits, Crackers, and Cookies (3rd ed.). Woodhead Publishing Limited and CRC Press LLC. p. 197. ISBN0-8493-0895-X.
^Chris Clarke (2004). The science of ice cream. Cambridge, Eng: Royal Society of Chemistry. p. 49. ISBN978-0-85404-629-4. Retrieved 2013-03-20. Egg yolk has the approximate composition (by weight) of 50% water, 16% protein, 9% lecithin, 23% other fat, 0.3% carbohydrate and 1.7% minerals.