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flour,finely ground, usually sifted, meal of graingrain,
in agriculture, term referring to the caryopsis, or dry fruit, of a cereal grass. The term is also applied to the seedlike fruits of buckwheat and of certain other plants and is used collectively for any plant that bears such fruits.
..... Click the link for more information. , such as wheat, rye, corn, rice, or buckwheat. Flour is also made from potatoes, peas, beans, peanuts, etc. Usually it refers to the finely ground and bolted (i.e., sifted through a fine sieve) flour of wheatwheat,
cereal plant of the genus Triticum of the family Poaceae (grass family), a major food and an important commodity on the world grain market. Wheat Varieties and Their Uses
..... Click the link for more information. , which forms the largest proportion of all flour milled in the United States, Canada, and W Europe. Milletmillet,
common name for several species of grasses cultivated mainly for cereals in the Eastern Hemisphere and for forage and hay in North America. The principal varieties are the foxtail, pearl, and barnyard millets and the proso millet, called also broomcorn millet and hog
..... Click the link for more information. is ground in India, Russia, and China. Rye is much used for bread in N Europe, buckwheat in the Netherlands and Russia, and corn in the United States. Rice may be used for bread in combination with other grains richer in glutengluten,
mixture of proteins present in the cereal grains. The long molecules of gluten, insoluble in water, are strong and flexible and form many cross linkages. This gives flour its characteristic chewiness and permits breads and cakes to rise during baking as the gases within
..... Click the link for more information. . Wheat and rye flour can be used in baking leavened bread, as they contain gluten in sufficient amount to retain the gas formed by the action of yeast. Corn flour, rich in fats and starches, is a favorite for making quick breads. Graham, or whole-wheat, flour contains the whole grain, unbolted. This flour will not keep long, as the germ contains fats and ferments that cause deterioration when exposed to the air. Wheat flour is separated into grades by milling. In the United States, patent flour, freed of the bran and most of the germ, is the highest grade; clear flour is the second grade; and red dog, a low-grade residue, is used mainly for animal feed. The composition of flour depends on the type of wheat and the milling processes; gluten is the chief protein, and starch the principal carbohydrate, although some sucrose, invert sugar, and dextrin may be present. On the market are prepared flours, such as the self-rising, which contains a leavening agent, and numerous cake, pancake, and pastry mixes requiring only the addition of water. Flour improves if stored from six to nine months under conditions permitting the enzyme action that gives better baking qualities. Good flour, rich in gluten, has a creamy color and adhesive quality. Bleaching, which is accomplished by the addition of chemicals to flour to improve its appearance and baking qualities, was begun about 1900. The bleaching of flour has been a controversial issue since its beginning, with charges that it destroys valuable nutrients or is injurious to health; some bleaching agents have been banned (e.g., nitrogen trichloride), but new ones have been introduced. Bleached flours must be so labeled.
a food product obtained by grinding the grain of various crops. Most often flour is made from wheat, but it may also be made from rye, barley, corn, oats, sorghum, buckwheat, soybeans, and peas. Flour is used for making bread and other baked goods, pastry, pasta products, and mixed feeds. In addition, it is mixed with other feeds and given to livestock.
The chemical composition, the nutritional value, and the technical qualities of flour depend on the type and quality of the grain, the particular type of milling, the yield (the percentage of flour in the total grain weight), and the grade of flour (see Table 1).
|Table 1. Chemical composition of wheat flour (in percentage of dry weight)|
|Patent flour ..........||14||73.6||10.8||0.2||0.9||0.5|
|First Clear ...........||14||72.9||11.0||0.3||1.1||0.7|
Whole wheat and low-grade flour contain vitamins B1, B2, PP, and E, while patent flour and first clear have virtually no vitamins. Flour also contains various enzymes (proteinase, beta-amylase, alpha-amylase, catalase, lipase), which greatly affect the process of bread-making and the quality of the bread. Rye flour is most often produced as a one-grade, or straight-grade, flour. Also produced are a straight-grade 96 percent wheat-rye flour (70 percent wheat and 30 percent rye) and a straight-grade 95 percent rye-wheat flour (60 percent rye and 40 percent wheat). The yield and the grade determine the flour’s color, particle size, and ash content; in wheat flour, they also determine the quality and quantity of the crude gluten. Good-quality flour has a slight floury aroma and a fresh taste.
When flour is stored, its quality can alter. During the first storage period (up to one month) and under conditions of increased temperature (20°-30°C), maturing occurs (an improvement in baking properties) as a result of fat hydrolysis and oxidation processes. With protracted storage, the quality of the flour deteriorates. The moisture content of flour should be no higher than 15 percent. Flour with higher moisture content turns sour, becomes moldy, and may self-heat; flour with lower moisture content (9–13 percent) rapidly turns bitter.
Flour must not be contaminated with granary pests. It should contain no more than 3 percent sprouted seed and 0.05 percent harmful impurities. Metal impurities (up to 3 mg/kg of flour) are permitted only in the form of round dustlike particles. The color, ash content, and particle size of the flour are also control indicators for the production process and for the correct extraction of the various grain parts. To obtain high-quality products, wheat flour, depending on its grade and yield, should contan at least 20–30 percent crude gluten of the first or second group. To determine the technical qualities of wheat flour, the elasticity of the dough during kneading and rising is recorded. The qualities of rye flour are determined on an amylograph, which indicates the viscosity of the flour paste and, thereby, the amylolytic activity of the flour and the degree of starch hydrolysis. The baking properties of a particular flour may be determined from experimental bakes using the same recipe. (See.)
L. A. TRISVIATSKII