Since childhood, we are familiar with such a grain crop as wheat. What is wheat, everyone knows, as well as the fact that without it it is difficult to imagine the diet of a modern person. Today we will deepen our knowledge about cereals, consider in detail its types, methods of cultivation, properties and much more.
general characteristics
Wheat, the photo of which is probably familiar to everyone, is a one- or two-year-old genus of cereal crops. Flour obtained from wheat grains is used for baking light grades of bread and the production of certain food products. Flour milling waste goes to livestock and poultry feed. In addition, in recent years they are increasingly used as industrial raw materials. The amazing wheat plant is the leading cereal in many countries of the world, and is a key food in northern China, parts of India and Japan, most countries in the Middle East and North Africa, and also in the plains of South America.
The main producer of wheat is China, and America is in second place. Following them are such large manufacturing countries: India, Russia, France, Canada, Ukraine, Turkey, Kazakhstan. Wheat grain is an important agricultural object of international trade, it accounts for almost 60% of grain exports. The main exporter of wheat is America. Followed by: Canada, France, Australia and Argentina. Major importers: Russia, China, Japan, Egypt, Brazil, Poland, Italy, Korea, Iraq and Morocco.
Wheat varieties number in the thousands and have a rather complicated classification, but there are two main types - hard and soft. Soft varieties are also divided into red and white. As a rule, they are grown in humid regions. Durum wheat is bred in a drier climate, for example, in areas where the steppe predominates. In Australia and Western Europe, mainly soft varieties are produced. And in regions such as America, Canada, North Africa, West Asia, Argentina and the countries of the former Soviet Union - mainly hard varieties.
Biology
We continue to get acquainted with such a plant as wheat. What is wheat from a biological point of view? This is the next question to answer. Like other cereals, wheat has a straw stem with nodes and hollow internodes. The leaves are simple, linear, two-row, alternate. Each of them departs from the node, and consists of a vagina, which covers the overlying internode like a split tube, and a narrow long plate. On the border between the plate and the vagina are three outgrowths: a membranous tongue, which is adjacent to the stem, and a pair of finger-shaped ears covering it.
The upper internode, which is also called the peduncle, carries an inflorescence - a complex spike. It includes a cranked central axis, and simple inflorescences branching from it - spikelets that face the axis with a wide side. On each spikelet, there are from two to five flowers extending to the sides, which are covered on the bottom side by a pair of spikelet scales. In addition, each flower is protected by a pair of bracts - a thick lower and relatively thin upper scales. In some varieties of wheat, the lower color scale ends with a long spine. Such varieties are called spinous.
Wheat flowers are usually bisexual. They have three stamens and a pestle bearing two cirrus stigmas. At the base of the eyeballs there are 2-3 small flower films (lodicles), which serve as the perianth. By the time of flowering, the lodicules swell and spread the scales surrounding the flower. Wheat is predominantly a self-pollinated plant, but there are species with cross-pollination. After fertilization, a small, solid fruit grows out of the ovary - a kernel, which is held in the spikelet thanks to flowering scales.
Grain, or as it is also called a grain, is a pericarp formed from the wall of the ovary, which is inextricably linked to the only seed containing the germ and endosperm. The embryo is located at the base of the grain, on the side, and includes the kidney, root, and a modified cotyledon adjacent to the endosperm - the scutellum. When the embryo sprouts, the root gives the primary root system, the bud - the "adult" roots of the plant and its aerial organs, and the scab secures enzymes for digesting the endosperm and carries its nutrients to the shoot, which had begun to develop by then. So young wheat begins its life. The photo below will help to more clearly understand the structure of its grain.
Grain sown in soil absorbs moisture, swells and sprouts. The germinal root and kidney go out and grow up and down, respectively. On the surface of the soil, from the first node of the straw, which is formed from the kidney, adventitious roots depart, which branch and form the urolithic root system. The place where the stem goes to the root is called the root neck. Just above the neck, the lower nodes of the stem are close to each other. From the axils of their leaves, lateral shoots develop. This process is called tillering of wheat.
During the described processes, the plant is called a shoot. Then comes the stage of exit into the tube - the rapid lengthening of the straw. Behind it comes the heading - the formation of inflorescences. During heading, the internode takes out an ear 8-10 centimeters above the top sheet.
The final grain size consists of a germ and a watery endosperm. First, the endosperm is transparent. As it increases in starch content, it turns white. This stage is called milk ripeness. The moisture content of the grain gradually decreases and its contents become like sticky dough. This stage is called wax ripeness. Ultimately, when the grain is fully ripe (technically ripe), it becomes hard.
The properties
So, we have already figured out what wheat is. What are hard and soft grades, we also know. Now let's talk about the properties due to which this culture has found such wide application. Soft and hard varieties, on the one hand, have much in common, and on the other hand, have a number of fundamental differences, which are definitely worth considering when using flour. According to historians, the difference between the two main types of wheat grains was known by the ancient Greeks and Romans, and maybe earlier civilizations.
The flour obtained from their common wheat has soft and rather large grains of starch, it has a thin and crumbly consistency, contains a little gluten and absorbs water less. This type of flour is used in baking confectionery. For bread, it is not suitable, since products from such flour quickly become stale and crumble heavily. In areas where soft flour is prevailing, bread is usually baked from a mixture of local soft varieties and imported solid.
Flour obtained from durum wheat has small and hard starch grains, a fine-grained texture, and is characterized by a high content of gluten. This flour is called “strong” because it absorbs a lot of water and is used in baking bread. Durum wheat pasta is also a popular product.
Application area
The importance of wheat in human life has always been significant. With the increase in the share of meat and other non-cereal products in the diet of people, the amount of wheat and other cereals they use is gradually decreasing. Wheat is also widely used as livestock feed. At the same time, its flour-grinding qualities practically do not affect the nutritional value. In America, for example, whole grains began to be used for feed, although grinding wastes were previously used.
Waste from flour milling was fed to livestock in ancient times. Waste with a high content of cellulose went to feed cattle and horses, and with a low content - to poultry and pigs. Wheat bran has always been valued as a nutritional supplement to the diet of ewes and pregnant cows. Previously, they were also given to horses, due to laxative properties. Small bran, which includes embryos and flour adhering to them, are best suited for pigs. It is most effective to use them together with fishmeal, dairy by-products and slaughterhouse waste, as an additive to grain feed. In poultry farming, especially broiler farming, the use of milling waste has been declining recently, due to the growing popularity of low fiber diets.
Sodium glutamate was first obtained from the protein contained in wheat grains. It is a substance that enhances the taste of foods. In Japan, monosodium glutamate is widely used in the manufacture of soy sauces. However, now they have learned to get it from the same soy.
Until recently, applied research on wheat was mainly aimed at improving its nutritional properties. Laboratory studies have shown that wheat gluten can become a raw material for the production of plastics, fibers and adhesives. The problem is that these products are brittle and well soluble in water, which means they do not represent commercial value.
In recent years, there has been a trend towards a decrease in bread consumption, which has revived interest in the study of non-traditional ways of using wheat. So, with the help of special processing, they learned how to make “soluble” dishes resembling semolina in appearance, make high-protein flakes for a quick breakfast from gluten, and use wheat starch to harden paper. And wheat seedlings, the beneficial properties of which were proved, began to be eaten raw.
The gluing and viscous properties of flour are used in industry. Flour is used as an additive to drilling fluids used in oil production. And when extracting gold from a solution, it serves as a flocculating agent. In addition, flour is used in the production of drywall for better bonding of the mineral and paper parts, and also serves as a filler of waterproof plywood adhesives. And these are just the most common ways to use wheat flour in industry.
Classification
From an economic point of view, far from all wheat matters. The value of the plant depends on the species. The most cost-effective, and therefore widespread, are three types of wheat: summer / soft / ordinary, durum, and dense / dwarf. The first species is grown around the world and is mainly used in baking. Grains of the second type are used for the production of pasta, as they are rich in gluten. This is a mixture of proteins that forms a sticky mass that binds the dough well and holds carbon dioxide bubbles in it. Thanks to gluten, the dough rises, and the bread becomes lush. As for dwarf wheat, the flour from it is used mainly for loose baking.
Summer wheat is bred in the largest volumes. Its spikelet scales have a comb structure only in the upper part. The lower floral scales are boneless. The straw of such wheat is usually hollow. From dwarf wheat, ordinary differs in elongated, loose or compact, dorsoventrally flattened ears. A distinctive feature of durum wheat is the sharp ridges located along the entire length of the spikelet scales. In addition, she usually has spinous lower floral scales. Durum wheat straw is usually not complete.
Wheat varieties are also divided into spring and winter. Spring wheat is usually grown in regions with too harsh winters. It is sown in the spring. Winter wheat is sown in autumn, and harvested next summer. This is the most common species, since it begins to develop earlier than spring wheat, ripens faster, and gives a higher yield.
Ecology
Wheat grows safely in a wide range of climatic conditions, and is bred in almost all agricultural areas, except perhaps the tropics. Therefore, the cultivation of wheat is developed almost all over the world. In resistance to cold, it loses only to barley, potatoes and some forage grasses. Heat for wheat is also not terrible, unless it is combined with high humidity. In the latter case, the grains suffer from various diseases, which reduces the profitability of their cultivation.
Despite the fact that this crop can grow almost everywhere, there are two main zones where wheat is grown especially productively. The first is between 30 and 55 degrees north latitude, and the second is between 25 and 40 degrees south latitude. The annual rainfall in these areas averages from 300 to 1100 mm. The optimal rainfall for a good crop is 250-1000 mm per year. Wheat growth occurs in the temperature range from 3 to 32 degrees. Due to too early sowing, seedlings can get sick, exactly as well as because of too late (if we are talking about winter wheat).
Spring wheat is usually sown from March to May, it all depends on local weather conditions. Crops begin to be harvested when the grain moisture drops to 13%. Spring wheat fully ripens in approximately 100 frost-free days. If you remove it earlier, you will have to resort to drying. And later harvesting is fraught with loss of volumes, as overripe grain begins to crumble to the ground.
Winter wheat is grown, among other things, for livestock feed. When the yields reach a length of 15-20 cm, grazing begins on the wheat field . If next year it is planned to collect grain from the same field, then grazing is stopped at the stage of transition of the plant to the tube. In some areas of America, wheat is sown with winter legumes, and mowed to silage and hay before flowering.
Recycling
Wheat grain has a brownish shell, which when grinded produces bran, rich in protein, vitamins and cellulose. Under the shell is an aleuron layer consisting of small granules. The germ at the base of the grain is rich in oils, proteins and minerals. Everything else is thin-layer endosperm cells, which are filled with starch grains and gluten, which gives the test viscosity.
During grinding - the operation to obtain flour from wheat grains, the problem arises of separating starch and gluten from other components of the grain. The fact is that due to the embryo the flour becomes sticky and quickly darkens, and due to the aleurone layer it acquires a brownish tint. As a result of the cleaning of flour, milling wastes are formed - bran and fine seeding (flour). They make up from 15 to 18% of the mass of refined grain.
Flour composition
Wheat, a photo of which is usually shown on packs of flour, is a very valuable grain. It contains a large amount of vitamins (group B, choline, PP, E and H), as well as macro- and microelements (calcium, potassium, magnesium, sodium, iron, phosphorus, aluminum, titanium, chlorine, nickel, tin, molybdenum, chrome, boron, zinc, selenium and others). Thus, wheat, the benefits and harms of which will be discussed a little below, contains almost all the minerals necessary for the life of the human body.
Varieties of flour
Flour is classified by grades. Let's consider each of them.
Top grade. It has a white color and is used for the preparation of flour products of the highest grade. The latter receive fine porosity and good volume. Flour is great for puff, yeast and shortcrust pastry.
First grade. It can be either white or yellowish. It is well suited for making pancakes, rolls, pies and other pastries. For high-quality confectionery and bakery products, such flour is not recommended.
Second grade. It has a yellowish or even grayish tint. From it turns out magnificent and porous pastries. Second-grade flour is used mainly for white bread and inedible pastries. The second grade of flour was most widely used in the baking of gingerbread and cookies.
Krupchatka. Light cream flour containing a large percentage of gluten. Used to make yeast dough that contains a lot of sugar and fat. Suitable for making muffin.
Wallpaper. It has relatively large, inhomogeneous particles. It has high moisture capacity and sugar-forming ability. It is used for baking mainly table varieties of bread.
Benefit and harm
We have already figured out what wheat is. What is flour, we also know. It remains only to deal with the useful and harmful properties of this very flour.
Flour helps speed up metabolism, stimulates brain function and the production of estrogen, protects the cardiovascular system, reduces the risk of gallstones, and helps treat osteoporosis and Alzheimer's disease. The substances contained in the flour soften the inflammatory processes in the human body, prevent the formation of free radicals in it, and protect it from certain diseases. Flour helps in the treatment of bronchitis and asthma.
Wheat, whose benefits are undeniable, has some disadvantages. The main disadvantage of wheat flour is its calorie content. In addition, it can increase pressure and cause allergic reactions.