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The Roller Mill was created by Hungarian bakers in the late 1860s [1] and its popularity spread worldwide throughout the 1900s. Roller mills now produce almost all non-whole grain flour. Enriched flour is flour that meets an FDA standard in the United States. Roller milled white enriched flour makes up over 90% of the flour that comes out of the United States.
In 2017, well over 90% of the United States commercial flour production was not whole grain. [2] Virtually all of this non-whole grain flour was produced on flour roller mills. These unique mills were first developed in Europe in the 1860s, [1] soon after were patented and introduced into the United States [3] and quickly came to dominate the world's flour milling industry as they continue to do today.
Flour roller mills were specifically designed to efficiently separate the bran and germ elements of the wheat kernel. What remains is the endosperm, generally referred to as white flour. White flour is often artificially enriched to restore some of the nutrition lost by separating out the bran and the germ elements. In the U.S., white flour is nearly always artificially enriched to restore some of the nutrition lost by removing the bran and germ elements. Enrichment rules vary among countries. [4]
Wheat and other grains grow on a stalk and have an outer covering known as the husk, or the hull, which is not nutritional to humans. When the hull is removed, it is often referred to as chaff. The edible part of the wheat kernel is a wheat berry composed of the bran (about 14% of the kernel volume), the germ (about 3% of the kernel volume), and the endosperm (about 83% of the kernel volume).
The wheat berries' outer protective shell is the bran. The bran is rich in dietary fiber and fatty acids, and contains significant quantities of starch, protein, vitamins, and minerals. The germ is a source of several nutrients, [5] including vitamin E, folate, phosphorus, thiamin, zinc, and magnesium, as well as fatty acids and fatty alcohols. The germ is also a source of fiber. The endosperm's natural purpose (like all fruits) is to give nutrition to the germ in the form of starch when the seed is planted in the soil and sprouts into a plant. It also contains some oils and protein.
In early America, flour mills used mill stones that were set close together and turned at high speed, crushing all the components of the wheat kernel into an indiscriminate flour. [6] This was generally referred to as low milling. [7] At the time, without refrigeration or sealed storage, the heightened water absorption properties of the crushed bran fiber and the oil-rich germ shortened the shelf life of this flour. It was also more attractive to insects and vermin. Sifting or bolting could separate some of the elements because the thicker bran seed coat of the soft winter wheat varieties would crack into relatively large fragments.[ citation needed ] In this era, the limited amount of endosperm that could be sifted into a whiter flour was understandably preferred by consumers. [8]
Stone milled soft white wheat, which is lower in protein, dominated United States production before the introduction of Red Fife hard red spring wheat in the 1860s and Turkey hard red winter wheat in the 1870s.[ citation needed ] The higher gluten and protein properties of these hard wheats offered better bread-making qualities than the soft wheat varieties. [9] U.S. commercial millers initially significantly discounted the hard wheats because the white endosperm that customers preferred could be more easily sifted from the soft wheats. [10]
However, millers worldwide began to experiment with high grinding, [11] or placing the mill stones further apart and turning them at slower speeds. [12] The process was to first crack the wheat kernel and then to extract the flour by a succession of grindings and siftings. The white endosperm flour yield was enhanced by the addition of device known as the middlings purifier, which sent a blast of air into the mixture of partially-ground kernels as they were being sifted, lifting the bran particles upward into a separate holding area. A patent was granted to George Christian for this device, [13] and the consistent output of high quality flour thus became known as patent flour. [10] However, the use of mill stones in this high grinding process soon proved not to be optimum.
The improved functionality of baked products made with a finer flour mixture first got international attention at the 1867 Paris International Exposition. [1] The Hungarian baking exhibitors clearly out performed their French counterparts. They credited the finer flour that Hungarian millers were able to produce by using more uniform steel rollers instead of mill stones for their higher quality baked goods. The notoriety of their flour was the motivation for staging the 1873 Vienna International Exhibition held to promote the merits of this new technology. A US Patent number 225,770: Grain-Crushing Roll employing the use of grooved steel rollers geared to mill at different speeds was later granted in the U.S.in 1880 to John Steven . [14] The obvious efficiency of the roller mill prompted adoption over the next decade and came to dominate the commercial flour industry. No all-millstone mills of any significance were built in the U.S. after that with the commercial flour grindstone virtually disappearing from the flour milling scene in all developed countries by the early 1900s. [15]
To enhance output, millers experimented with flour tempering, [16] or hydrating the outer shell of the wheat berry, which facilitates the elimination of the bran and the germ. This is now a key step in the roller milling production of white endosperm flour. In contrast, whole grain milling systems that process the entire wheat kernel in one pass keep the grain as dry as possible. In 2017, these "single stream" systems actually produced a modest amount of the whole grain flour that was commercially milled. Most of the commercial whole grain flour produced is reconstituted or recombined after first being separated by roller mills. [17]
In the 1930s and 1940s, specific deficiency disease syndromes were first identified and documented in the United States. [18] In order to improve the nutritional status of the population, in 1941 the FDA established a standard of identity for any flour labeled as enriched. These standards have been amended over the years, but they continue as the basis for the addition of thiamine, niacin, riboflavin, folic acid, and iron, with the addition of calcium as optional. Under this regulation, fortification of flour and bread products is not mandatory, but if a product is labeled as enriched, it must meet the standards of identity described in the FDA regulations. The National Labeling Education Act of 1990 provided for federal preemption of standards of identity, nullifying any state laws that made enrichment of flour and bread products mandatory. [4]
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many cultures. Corn flour has been important in Mesoamerican cuisine since ancient times and remains a staple in the Americas. Rye flour is a constituent of bread in both Central Europe and Northern Europe.
Semolina is the name given to coarsely milled durum wheat mainly used in making pasta and sweet puddings. The term semolina is also used to designate coarse millings of other varieties of wheat, and sometimes other grains as well.
Bran, also known as miller's bran, is the component of a cereal grain consisting of the hard layers - the combined aleurone and pericarp - surrounding the endosperm. Corn (maize) bran also includes the pedicel. Along with the germ, it is an integral part of whole grains, and is often produced as a byproduct of milling in the production of refined grains. Bran is highly nutritious, but is difficult to digest due to its high fiber content; its high fat content also reduces its shelf life as the oils/fats are prone to becoming rancid. As such, it is typically removed from whole grain during the refining process - e.g. in processing wheat grain into white flour, or refining brown rice into white rice.
White bread typically refers to breads made from wheat flour from which the bran and the germ layers have been removed from the whole wheatberry as part of the flour grinding or milling process, producing a light-colored flour.
Wheat flour is a powder made from the grinding of common wheat used for human consumption. Wheat varieties are called "soft" or "weak" if gluten content is low, and are called "hard" or "strong" if they have high gluten content. Hard flour, or bread flour, is high in gluten, with 12% to 14% gluten content, and its dough has elastic toughness that holds its shape well once baked. Soft flour is comparatively low in gluten and thus results in a loaf with a finer, crumbly texture. Soft flour is usually divided into cake flour, which is the lowest in gluten, and pastry flour, which has slightly more gluten than cake flour.
Enriched flour is flour with specific nutrients added to it. These nutrients include iron and B vitamins. Calcium may also be supplemented. The purpose of enriching flour is to replenish the nutrients in the flour to match the nutritional status of the unrefined product. This differentiates enrichment from fortification, which is the process of introducing new nutrients to a food.
The germ of a cereal grain is the part that develops into a plant; it is the seed embryo. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ oil, rice bran oil, and maize bran, may be used as a source from which vegetable oil is extracted, or used directly as a food ingredient. The germ is retained as an integral part of whole-grain foods. Non-whole grain methods of milling are intended to isolate the endosperm, which is ground into flour, with removal of both the husk (bran) and the germ. Removal of bran produces a flour with a white rather than a brown color and eliminates fiber. The germ is rich in polyunsaturated fats and so germ removal improves the storage qualities of flour.
A whole grain is a grain of any cereal and pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm.
Brown bread is bread made with significant amounts of whole grain flours, usually wheat sometimes with corn and or rye flours. Brown breads often get their characteristic dark color from ingredients such as molasses or coffee. In Canada, Ireland and South Africa, it is whole wheat bread; in New England and the Maritimes, it is bread sweetened with molasses. In some regions of the US, brown bread is called wheat bread to complement white bread.
Refined grains have been significantly modified from their natural composition, in contrast to whole grains. The modification process generally involves the mechanical removal of bran and germ, either through grinding or selective sifting.
Wheat middlings are the product of the wheat milling process that is not flour. A good source of protein, fiber, phosphorus, and other nutrients, they are a useful fodder for livestock and pets. They are also being researched for use as a biofuel.
Sprouted bread is a type of bread made from whole grains that have been allowed to sprout. There are a few different types of sprouted grain bread. Some are made with additional added flour; some are made with added gluten; and some, such as Essene bread and Ezekiel bread are made with very few additional ingredients.
Maize miller is the processing of maize (corn) for safe and palatable consumption as food. Processing can be by machine-milling in either large- or small-scale mills, or by hand-milling in domestic or community settings.
Whole wheat bread or wholemeal bread is a type of bread made using flour that is partly or entirely milled from whole or almost-whole wheat grains, see whole-wheat flour and whole grain. It is one kind of brown bread. Synonyms or near-synonyms for whole-wheat bread outside the United States are whole grain bread or wholemeal bread. Some regions of the US simply called the bread wheat bread, a comparison to white bread. Some whole-wheat loaves are traditionally coated with whole or cracked grains of wheat, for cosmetic rather than nutritional reasons.
A Unifine mill is a single one-pass impact milling system which produces ultrafine-milled whole-grain wheat flour that requires no grain pre-treatment and no screening of the flour. Like the grist or stone mills that had dominated the flour industry for centuries, the bran, germ, and endosperm elements of grain are processed into a nutritious whole wheat flour in one step. Consumers had accepted whole wheat products produced by grist or stone mills. The flour produced by these mills was quite coarse as they included the bran and the germ elements of the grain.
In agriculture, grain quality depends on the use of the grain. In ethanol production, the chemical composition of grain such as starch content is important, in food and feed manufacturing, properties such as protein, oil and sugar are significant, in the milling industry, soundness is the most important factor to consider when it comes to the quality of grain. For grain farmers, high germination percentage and seed dormancy are the main features to consider. For consumers, properties such as color and flavor are most important.
John Stevens was a miller and inventor who lived in Neenah, Wisconsin. His inventions in flour milling revolutionized the process, leading to large-scale shifts in wheat-growing regions, and to the predominance of particular milling companies and mill-equipment manufacturers. Today Patent flour is still referred to due to Stevens' patents.
Whole-wheat flour or wholemeal flour is a powdery substance, a basic food ingredient, derived by grinding or mashing the whole grain of wheat, also known as the wheatberry. Whole-wheat flour is used in baking of breads and other baked goods, and also typically mixed with lighter "white" unbleached or bleached flours to restore nutrients, texture, and body to the white flours that can be lost in milling and other processing to the finished baked goods or other food(s).
Graham flour is a type of coarse-ground flour of whole wheat named after Sylvester Graham. It is similar to conventional whole-wheat flour in that both are made from the whole grain, but graham flour is ground more coarsely. It is not sifted ("bolted") with a flour dresser after milling. A report from 1913 claimed that bread made from graham flour had a protein content of 12.1%—only slightly less than white wheat flour and essentially the same as whole wheat flour.
Flour extraction is the common process of refining Whole Grain Flour first milled from grain or grist by running it through sifting devices, often called flour dressers.