Bread is a staple food prepared from a dough of flour (usually wheat) and water, usually by baking. Throughout recorded history and around the world, it has been an important part of many cultures' diet. It is one of the oldest human-made foods, having been of significance since the dawn of agriculture, and plays an essential role in both religious rituals and secular culture.
Bread may be Leavening agent by naturally occurring microbes (e.g. sourdough), chemicals (e.g. baking soda), industrially produced yeast, or high-pressure aeration, which creates the gas bubbles that fluff up bread. In many countries, commercial bread often contains additives to improve flavor, texture, color, shelf life, nutrition, and ease of production.
An early leavened bread was baked as early as 6000 BC in southern Mesopotamia, cradle of the Sumerians civilization, who may have passed on the knowledge to the Egyptians around 3000 BC. The Egyptians refined the process and started adding yeast to the flour. The Sumerians were already using ash to supplement the dough as it was baked.Arzani A.: Emmer (Triticum turgidum spp. dicoccum) flour and breads. In Preedy V.R., Watson R.R., Patel V.B. (Eds. 2011), Flour and Breads and their Fortification in Health and Disease Prevention, Academic Press, California, pp. 69-78.
There were multiple sources of leavening available for early bread. Airborne yeasts could be harnessed by leaving uncooked dough exposed to air for some time before cooking. Pliny the Elder reported that the Gauls and Iberians used the foam skimmed from beer, called barm, to produce "a lighter kind of bread than other peoples" such as barm cake. Parts of the ancient world that drank wine instead of beer used a paste composed of grape juice and flour that was allowed to begin fermenting, or wheat bran steeped in wine, as a source for yeast. The most common source of leavening was to retain a piece of dough from the previous day to use as a form of sourdough Bread starter, as Pliny also reported.
The ancient Egyptians, Greeks, and Romans all considered the degree of refinement in the bakery arts as a sign of civilization.
The Chorleywood bread process was developed in 1961; it uses the intense mechanical working of dough to dramatically reduce the fermentation period and the time taken to produce a loaf. The process, whose high-energy mixing allows for the use of grain with a lower protein content, is now widely used around the world in large factories. As a result, bread can be produced very quickly and at low costs to the manufacturer and the consumer. However, there has been some criticism of the effect on nutritional value. Chorleywood Industrial Bread Making Process. allotment.org.uk bbc.com: "Chorleywood: The bread that changed Britain" , 7 June 2011
Gluten-free breads are made using flours from a variety of ingredients such as almonds, rice, sorghum, corn, legumes such as beans, and tubers such as cassava. Since these foods lack gluten, dough made from them may not hold its shape as the loaves rise, and their crumb may be dense with little aeration. Additives such as xanthan gum, guar gum, hydroxypropyl methylcellulose (HPMC), corn starch, or eggs are used to compensate for the lack of gluten.
Rye bread contains and ferulic acid dehydrodimers.
Three glucosides, secoisolariciresinol diglucoside, p-coumaric acid glucoside and ferulic acid glucoside, can be found in commercial breads containing flaxseed.
Glutenin and gliadin are functional proteins found in wheat bread that contribute to the structure of bread. Glutenin forms interconnected gluten networks within bread through interchain disulfide bonds. Gliadin binds weakly to the gluten network established by glutenin via intrachain disulfide bonds. Structurally, bread can be defined as an elastic-plastic foam (same as styrofoam). The glutenin protein contributes to its elastic nature, as it is able to regain its initial shape after deformation. The gliadin protein contributes to its plastic nature, because it demonstrates non-reversible structural change after a certain amount of applied force. Because air pockets within this gluten network result from carbon dioxide production during leavening, bread can be defined as a foam, or a gas-in-solid solution.
Acrylamide, like in other starchy foods that have been heated higher than 120 °C (248 °F), has been found in recent years to occur in bread. Acrylamide is Neurotoxicity, has adverse effects on male reproduction and developmental toxicity and is . A study has found that more than 99 percent of the acrylamide in bread is found in the crust.
A study by the University of Hohenheim found that industrially produced bread typically has a high proportion of FODMAP carbohydrates due to a short rising time (often only one hour). The high proportion of FODMAP carbohydrates in such bread then causes flatulence. This is particularly problematic in intestinal diseases such as irritable bowel syndrome. While in traditional bread making the dough rises for several hours, industrial breads rise for a much shorter time, usually only one hour. However, a sufficiently long rising time is important to break down the indigestible FODMAP carbohydrates. Some flours (for example, spelt, emmer and Einkorn wheat) contain fewer FODMAPs, but the difference between grain types is relatively small (between 1 and 2 Weight percent). Instead, 90% of the FODMAPs that cause discomfort can be broken down during a rising time of 4 hours. In the study, whole-grain yeast doughs were examined after different rising times; the highest level of FODMAPs was present after one hour in each case and decreased thereafter. The study thus shows that it is essentially the baking technique and not the type of grain that determines whether a bread is well tolerated or not. A better tolerance of bread made from original cereals can therefore not be explained by the original cereal itself, but rather by the fact that traditional, artisanal baking techniques are generally used when baking original cereals, which include a long dough process. The study also showed that a long rising time also breaks down undesirable phytates more effectively, flavors develop better, and the finished bread contains more biologically accessible .
Bread is used as an ingredient in other culinary preparations, such as the use of to provide crunchy crusts or thicken sauces; toasted cubes of bread, called croutons, are used as a salad topping; seasoned bread is used as stuffing inside roasted turkey; sweet or savoury are made with bread and various liquids; egg and milk-soaked bread is fried as French toast; and bread is used as a binding agent in , and other ground meat products.
Methods of processing dough into bread include the Straight dough, the Sourdough, the Chorleywood bread process and the sponge and dough process.
Calcium propionate is commonly added by commercial bakeries to retard the growth of molds.
Wheat flour, in addition to its starch, contains three water-soluble protein groups (albumin, globulin, and ) and two water-insoluble protein groups (glutenin and gliadin). When flour is mixed with water, the water-soluble proteins dissolve, leaving the glutenin and gliadin to form the structure of the resulting bread. When relatively dry dough is worked by kneading, or wet dough is allowed to rise for a long time (see no-knead bread), the glutenin forms strands of long, thin, chainlike molecules, while the shorter gliadin forms bridges between the strands of glutenin. The resulting networks of strands produced by these two proteins are known as gluten. Gluten development improves if the dough is allowed to autolyse.
Mixtures of salts are sometimes employed, such as employing potassium chloride to reduce the sodium level, and monosodium glutamate to give flavor (umami).
The baker's yeast and sourdough methods follow the same pattern. Water is mixed with flour, salt and the leavening agent. Other additions (spices, herbs, fats, seeds, fruit, etc.) are not needed to bake bread, but are often used. The mixed dough is then allowed to rise one or more times (a longer rising time results in more flavor, so bakers often "punch down" the dough and let it rise again), loaves are formed, and (after an optional final rising time) the bread is baked in an oven.
Many breads are made from a "straight dough", which means that all of the ingredients are combined in one step, and the dough is baked after the rising time; others are made from a "pre-ferment" in which the leavening agent is combined with some of the flour and water a day or so ahead of baking and allowed to ferment overnight. On the day of baking, the rest of the ingredients are added, and the process continues as with straight dough. This produces a more flavorful bread with better texture. Many bakers see the starter method as a compromise between the reliable results of baker's yeast and the flavor and complexity of a longer fermentation. It also allows the baker to use only a minimal amount of baker's yeast, which was scarce and expensive when it first became available. Most yeasted pre-ferments fall into one of three categories: "poolish" or "pouliche", a loose-textured mixture composed of roughly equal amounts of flour and water (by weight); "biga", a stiff mixture with a higher proportion of flour; and "pâte fermentée", which is a portion of dough reserved from a previous batch.
Sourdough breads are made with a sourdough starter. The starter cultivates yeast and lactobacilli in a mixture of flour and water, making use of the microorganisms already present on flour; it does not need any added yeast. A starter may be maintained indefinitely by regular additions of flour and water. Some bakers have starters many generations old, which are said to have a special taste or texture. At one time, all yeast-leavened breads were sourdoughs. Recently there has been a revival of sourdough bread in artisan bakeries.
Traditionally, peasant families throughout Europe baked on a fixed schedule, perhaps once a week. The starter was saved from the previous week's dough. The starter was mixed with the new ingredients, the dough was left to rise, and then a piece of it was saved to be the starter for next week's bread.
The Pressure-Vacuum mixer was later developed by the Flour Milling and Baking Research Association for the Chorleywood bread process. It manipulates the gas bubble size and optionally the composition of gases in the dough via the gas applied to the headspace.
In many , bread is a metaphor for basic necessities and living conditions in general. For example, a "bread-winner" is a household's main economic contributor and has little to do with actual bread-provision. This is also seen in the phrase "putting bread on the table". The Roman poet Juvenal satirized superficial politicians and the public as caring only for " panem et circenses" (bread and circuses). In Russia in 1917, the Bolsheviks promised "peace, land, and bread." The term "breadbasket" denotes an agriculturally productive region. In parts of Northern Europe, Central Europe, Southern Europe and Eastern Europe Europe bread and salt is offered as a welcome to guests. In India, life's basic necessities are often referred to as "roti, kapra aur makan" (bread, cloth, and house).
Words for bread, including "dough" and "bread" itself, are used in English language-speaking countries as for money. A remarkable or revolutionary innovation may be called the best thing since "sliced bread". The expression "to break bread with someone" means "to share a meal with someone". The English word "lord" comes from the Anglo-Saxon hlāfweard, meaning "bread keeper."
Bread is sometimes referred to as "the staff of life", although this term can refer to other staple foods in different cultures: the Oxford English Dictionary defines it as "bread (or similar staple food)". OED cites 1638 "Bread is worth all, being the Staffe of life" but also 1901 "Broad beans form one of the staves of life in Sicily". This is sometimes thought to be a biblical reference, but the nearest wording is in Leviticus 26 "when I have broken the staff of your bread". The term has been adopted in the names of bakery firms. An example
Types
Properties
Physical-chemical composition
Culinary uses
Nutritional significance
Crust
Preparation
Formulation
Flour
Liquids
Fats or shortenings
Bread improvers
Salt
Leavening
Chemicals
Yeast
Sourdough
Steam
Bacteria
Aeration
Culture
Etymology
Cultural significance
See also
Further reading
External links
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