|Main ingredients||Flour, water|
A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to bread dough 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. 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. 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.
These agents are often sold as mixtures in a soy flour base, as only small amounts are required.
Examples of dough conditioners include ascorbic acid, distilled monoglycerides, citrate ester of monoglycerides, diglycerides, ammonium chloride, enzymes, diacetyl tartaric acid ester of monoglycerides or DATEM, potassium bromate, calcium salts such as calcium iodate, L-cystine, L-cysteine HCl, glycerol monostearate, azodicarbonamide, sodium stearoyl lactylate, sucrose palmitate or sucrose ester, polyoxyethylene sorbitan monostearate or polysorbate, soybean lecithin, and soybean lecithin enriched with lysophospholipids.
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. Robertson et al. point out that some of the better information is found in baking books published back when bakers were still kneading by hand.
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." They contain water conditioners, yeast conditioners, and dough conditioners.
Yeast requires water, carbon sources such as starch and simple carbohydrates, nitrogen preferably as ammonium as it cannot assimilate nitrate, sulfur, phosphorus (often as inorganic phosphate), and minute quantities of vitamins and elemental mineral ions including B, Ca, Co, Cu, Fe, K, Mo, Mn, Mg, Ni, and Zn. Ammonium chloride, ammonium sulfate, or ammonium phosphate may be used as sources of nitrogen. Phosphoric acid, an acidulant, is used as a yeast stimulant. Calcium iodate, an oxidant, is a U.S. Food and Drug Administration generally recognized as safe or GRAS source of calcium.
Oxidants and reductants
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. 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 (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. Cysteine and bisulfite[note 1] are reducing agents which relax wheat dough. Adding minute amounts of oxidants or reducing agents alter the post-mix handling characteristics of dough. 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)
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. Lecithin added at a rate of 0.25-to-0.6% of the flour weight acts as a dough conditioner. Based on total weight, egg yolk contains about 9% lecithin. Monoglycerides and diglycerides replace eggs in baked goods. Emulsifiers tend to produce a finer grain, softer crumb, and with longer proof times, increased baked volume.
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:
- Lallemand Baking Update. "Dough conditioners" (PDF).
- Wolfgang Aehle, ed. (2007). Enzymes in Industry: Production and Applications. Weinheim: Wiley-VCH. ISBN 978-3-527-31689-2.
- Yamada, Y.; Preston, K.R. (1994). "Sponge-and-dough bread: Effects of oxidants on bread and oven rise properties of a Canadian red spring wheat patent flour" (PDF). Cereal Chemistry. 73 (3): 297–300.
- 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. S2CID 84732563.
- "Frequently Asked Questions on Azodicarbonamide (ADA)". FDA.
- Clyde E. Stauffer (1990). Functional Additives for Bakery Foods. Van Nostrand Reinhold. p. 8. ISBN 978-0442003531. LCCN 90-37356.
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....
- Gómez, M.; Del Real, S.; Rosell, C.M.; Ronda, F.; Blanco, C.A.; Caballero, P.A. (2004). "Functionality of different emulsifiers on the performance of breadmaking and wheat bread quality". European Food Research and Technology. 219 (2): 145–150. doi:10.1007/s00217-004-0937-y. S2CID 94414171.
- Laurel Robertson; Carol Flinders; Bronwen Godfrey (2003). The Laurel's kitchen bread book: a guide to whole-grain breadmaking (Random House trade paperback ed.). New York: Random House. ISBN 978-0-8129-6967-2. Retrieved May 14, 2011. See also article: Laurel's Kitchen.
- "The Journal of the American Medical Association". 71 (1). American Medical Association. 1918: 282. Cite journal requires
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- Fulmer, E.I.; Nelson, V.E.; Sherwood, F.F. (1921). "The Nutritional Requirements Of Yeast. II. The Effect Of The Composition Of The Medium On The Growth Of Yeast". Journal of the American Chemical Society. 43 (1): 191–199. doi:10.1021/ja01434a027.
- Di Carlo, F.J.; Schultz, A.S.; McManus, D.K. (1951). "The assimilation of nucleic acid derivatives and related compounds by yeasts" (PDF). Journal of Biological Chemistry. 189 (1): 151–157. PMID 14832226.
- Claudia Ruiz-Capillas; Leo M.L. Nollet, eds. (2016). Flow Injection Analysis of Food Additives (PDF). CRC Press. p. 262. ISBN 978-1-4822-1820-6.
- 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. PMID 15240625.
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.
- "CALCIUM IODATE".
- Fairweather-Tait, S.J.; Teucher, B. (2002). "Iron and calcium bioavailability of fortified foods and dietary supplements". Nutrition Reviews. 60 (11): 360–367. doi:10.1301/00296640260385801. PMID 12462518.
- Swoboda, F.K. (1922). "Nitrogen nutrition of yeast" (PDF). Journal of Biological Chemistry. 52 (1): 91–109.
- Hui and Corke 2006, p. 233.
- "Ascorbic acid". Sustain. Retrieved 8 July 2014.
- Manley, Duncan (2000). Technology of Biscuits, Crackers, and Cookies (3rd ed.). Woodhead Publishing Limited and CRC Press LLC. p. 197. ISBN 0-8493-0895-X.
- Lallemand Baking Update. "A Guide to Reducing Agents" (PDF).
- Baking Association of Canada. "L-Cysteine" (PDF).
- Dong, W.; Hoseney, R.C. (1995). "Effects of Certain Breadmaking Oxidants and Reducing Agents on Dough Rheological Properties" (PDF). Cereal Chemistry. 72 (1): 58–64.
- Elkassabany, M.; Hoseney, R.C.; Seib, P.A. (1980). "Ascorbic Acid as an Oxidant in Wheat Flour Dough. I. Conversion to Dehydroascorbic Acid" (PDF). Cereal Chemistry. 57 (2): 85–87.
- Elkassabany, M.; Hoseney, R.C. (1980). "Ascorbic Acid as an Oxidant in Wheat Flour Dough. II. Rheological Effects" (PDF). Cereal Chemistry. 57 (2): 88–91.
- Popper, Lutz. "18.3 Oxidation and Flour Maturation" (PDF).
- "Sodium Bisulfite". BAKER-pedia.
- Brown, Amy L. (2008). Understanding food: principles and preparation. Belmont, CA: Thomson/Wadsworth. p. 352. ISBN 978-0-495-10745-3. Retrieved 2013-03-20.
- O'Brien, Richard (2008). Fats and Oils Formulating and Processing for Applications, Third Edition: Formulating and Processing for Applications, Second Edition. Boca Raton: CRC. p. 319. ISBN 978-1-4200-6166-6. Retrieved 2013-03-20.
Protein complexing: The ability to complex with the protein in flour (gluten) provides the basis for a good dough conditioner. Lecithin can function as a natural bread-dough conditioner at addition levels generally between 0.25 and 0.6% based on the weight of the flour.
- Chris Clarke (2004). The science of ice cream. Cambridge, Eng: Royal Society of Chemistry. p. 49. ISBN 978-0-85404-629-4. 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.
- "Hostess Bankruptcy And Science Prove Twinkies Are Not Immortal.. (n.d.)". The Free Library. 2014. Retrieved Sep 28, 2014.
The cake also has emulsifying chemicals called monoglycerides and diglycerides, which replace most of the eggs that would normally be used in a baked good.
- Sun, Da-Wen (2011). Handbook of Frozen Food Processing and Packaging, Second Edition (Contemporary Food Engineering). Boca Raton: CRC Press. p. 518. ISBN 978-1-4398-3604-0. Retrieved 2013-03-20.
- Tenbergen, Klaus. "Dough and Bread Conditioners". Food and Product Design Magazine. Retrieved 31 July 2012.
- Hui Y and Cork H (2006). Bakery products: science and technology. Blackwell Publishing.
- Is ADA our friend or foe? at Bakerpedia