Bread
Bread is a baked food product made from water, flour, and often yeast. It is a staple food across the world, particularly in Europe and the Middle East. Throughout recorded history and around the world, it has been an important part of many cultures' diets. 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 leavened by naturally occurring microbes, chemicals, industrially produced yeast, or high-pressure aeration, which creates the gas bubbles that fluff up bread. Bread may also be unleavened. In many countries, mass-produced bread often contains additives to improve flavor, texture, color, shelf life, nutrition, and ease of production.
Etymology
The same word as exists today is within Bald's Leechbook from either the 10th or 9th century. At some time the Old English was brēotan.The Middle and Modern English word bread appears in other Germanic languages, such as,,,, and Norwegian and ; perhaps with a Germanic base in brew or perhaps to break, originally meaning "broken piece", "morsel" - altogether though it is not possible to state the etymology with certainty.
History
Bread is one of the oldest prepared foods. Evidence from 30,000 years ago in Europe and Australia revealed starch residue on rocks used for pounding plants. It is possible that during this time, starch extract from the roots of plants, such as cattails and ferns, was spread on a flat rock, placed over a fire and cooked into a primitive form of flatbread. The oldest evidence of bread-making has been found in a 14,500-year-old Natufian site in Jordan's northeastern desert. Around 10,000 BC, with the dawn of the Neolithic age and the spread of agriculture, grains became the mainstay of making bread. Yeast spores are ubiquitous, including on the surface of cereal grains, so any dough left to rest leavens naturally.An early leavened bread was baked as early as 6000 BC in southern Mesopotamia, cradle of the Sumerian 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.
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 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.
Types
Bread is the staple food of the Middle East, Central Asia, North Africa, Europe, and in European-derived cultures such as those in the Americas, Australia, and Southern Africa. This is in contrast to parts of South and East Asia, where rice or noodles are the staple. Bread is usually made from a wheat-flour dough that is cultured with yeast, allowed to rise, and baked in an oven. Carbon dioxide and ethanol vapors produced during yeast fermentation result in bread's air pockets. Owing to its high levels of gluten, common or bread wheat is the most common grain used for the preparation of bread, which makes the largest single contribution to the world's food supply of any food.Bread is also made from the flour of other wheat species. Non-wheat cereals including rye, barley, maize, oats, sorghum, millet and rice have been used to make bread, but, with the exception of rye, usually in combination with wheat flour as they have less gluten.
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, corn starch, or eggs are used to compensate for the lack of gluten.
Properties
Physical-chemical composition
In wheat, phenolic compounds are mainly found in hulls in the form of insoluble bound ferulic acid, where it is relevant to wheat resistance to fungal diseases.Rye bread contains phenolic acids and ferulic acid dehydrodimers.
Three natural phenolic glucosides, secoisolariciresinol diglucoside, p-coumaric acid glucoside and ferulic acid glucoside, can be found in commercial breads containing flaxseed.
File:Small home made bread with pumpkin and sunflower seeds.jpg|thumb|upright|Small homemade bread with pumpkin and sunflower seeds
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. 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, has been found in recent years to occur in bread. Acrylamide is neurotoxic, has adverse effects on male reproduction and developmental toxicity and is carcinogenic. 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. 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 contain fewer FODMAPs, but the difference between grain types is relatively small. Instead, 90% of the FODMAPs that cause discomfort can be broken down during a rising time of four 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 trace elements.
Culinary uses
Bread can be served at many temperatures; once baked, it can subsequently be toasted. It is most commonly eaten with the hands, either by itself or as a carrier for other foods. Bread can be spread with butter, dipped into liquids such as gravy, olive oil, or soup; it can be topped with various sweet and savory spreads, or used to make sandwiches containing meats, cheeses, vegetables, and condiments.Bread is used as an ingredient in other culinary preparations, such as the use of breadcrumbs 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 bread puddings 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 sausages, meatballs and other ground meat products.
Nutritional significance
Bread is a good source of carbohydrates and micronutrients such as magnesium, iron, selenium, and B vitamins. Whole grain bread is a good source of dietary fiber and all breads are a common source of protein in the diet, though not a rich one.Crust and crumb
The mass of bread consists of two primary components: the crust and crumb.Bread crust is formed from surface dough during the cooking process. It is hardened and browned through the Maillard reaction using the sugars and amino acids due to the intense heat at the bread surface. The crust of most breads is harder, and more complexly and intensely flavored, than the rest. Old wives' tales suggest that eating the bread crust makes a person's hair curlier. Additionally, the crust is rumored to be healthier than the remainder of the bread. Some studies have shown that this is true as the crust has more dietary fiber and antioxidants such as pronyl-lysine.
Bread crumb is the internal porous material consisting of bubbles with elastic walls. As the bread ages, the crumb becomes more firm.