The grain grain crops include water, organic and minerals, as well as enzymes and vitamins. The composition of the grain may vary depending on the conditions of growth, the level of agricultural engineering and varieties.

Water Always present in the grain in one or another quantity. The water content depends on the culture, its anatomical features, the number of hydrophilic colloids, the degree of ripeness, the conditions of cleaning and storage. Water in grain can be in the following sections:

chemically bound water is part of the molecules of substances in strictly certain ratios. It is possible to select such water only by calcining or chemical exposure, while the structure of substances in the grain walking is occurring;

physico - chemically bound water is part of the grain in various, not strictly defined relations, this form includes adsorptionally connected, osmotically absorbed and structural water. Water molecules, sorbed by hydrophilic colloids, lose the properties of the solvent, cannot easily move and participate in chemical reactions, so physiological processes are minimized;

mechanically connected water is placed in micro and maccapillars of grain. It has all the properties of ordinary water and is called free, easily removed when drying. Water removed from the grain during drying is called hygroscopic, includes loose water and physically connected.

The moisture content of grain during harvesting of different crops, depending on climatic conditions, fluctuates in large limits - from 10 ... 12 to 25 ... 30% or more. Grain with high humidity dried, bringing it to an air-silver state (humidity 14 ... 15%).

Nitrogenous substances - the most important part of the grain bread Zlakov. The main mass of nitrogenous substances in the grain is proteins. The content of non-protein nitrogen substances in the ripe grain does not exceed 2 ... 3% of the total amount of nitrogen substances, which are mainly represented by free amino acids and amides.

In terms of energy, proteins are superior to starch, sugar and inferior only with vegetable oils. Rich in proteins solid wheat. The content of protein in the grain of all breads increases with the promotion of their crops from north to south and from west to east. Climate dryness and increased nitrogen content in the soil affect the quality of grain. Increase the protein content in the grain, using the appropriate cultivation technology. The largest accumulation of it in the grain is promoted by the placement on the best predecessors, the use of organic and mineral fertilizers, protection of crops from pests and diseases, timely cleaning. When the wheat harvesting in the waxing phase, the Beck content is higher than with full ripeness.

Proteins are the main material when building cells and tissues in humans and animals. They are divided into simple and complex: nucleoproteins, lipoproteins that differ more complex chemical composition. Simple proteins mainly include the following fractions: albumin (water-soluble proteins), globulins (proteins soluble in weak solutions of neutral salts), glyadins (proteins soluble in 70 ... 80% ethyl alcohol), glutenins (proteins soluble in weak solutions acids and alkalis). Glyadins and glurats are the greatest value. For bakery, their ratio is better than 1: 1.

The quality of the protein is determined according to the composition of amino acids: the more essential and limiting acids (canalin, lysine, tryptophan, etc.), the higher the food and feed dignity of cultures.

Proteins insoluble in water are called gluten or gluten. Gluten is a bunch of protein substances remaining after laundering a dough from starch and other components. In addition to proteins in gluten, it is contained in not large quantities Starch, fat and other substances. The taste and bakery properties of flour depend on the quality and amount of gluten. The content of crude gluten fluctuates in wheat in the limits of 1 b ... 52%, y rye - 8 ... 26, y barley - 6 ... 20, y triticale - 28 ... 44%. Good gluten is capable of stretching in length and without breaking, to resist stretching. Wheat gluten is characterized by higher bakery qualities compared to rye, thanks to which wheat bread is characterized by high porosity and digestibility. The content and quality of gluten strongly affect the external conditions, the level of agricultural and used varieties. The gluten content increases with the use of organic and mineral fertilizers, compliance with the cultivation technology, and also with hot weather during the gulf of grain. In case of damage to wheat grain, its quality is significantly reduced by clusters.

Carbohydrates In the grains of mattal crops, the mainly polysaccharides are presented, among which most of the starch is. Its largest is contained in endosperm (about 80% of all carbohydrates). The rest of the amount falls on soluble carbohydrates - sugars (2 ... 3%) located mainly in the embryo. Most of all carbohydrates is located in the central part of the grain, less - by periphery. Depending on the nature of the location of the starch grains in the cells of the endosperm grain bread crops Maybe milder or vitreous. In grain with mildery endosperm, the gaps between large starch grains are filled with a plurality of small starch grains, the protein layer is thin.

In the vitreous grains of small starch grains, there is almost no, and the strayci is filled with proteins. The content of starch in the grain increases as the crops are promoted to the West and north, i.e. it changes in the opposite direction compared with the change in the amount of protein.

Fat - This is a spare high-energy substance, used in breathing and during germination of the embryo. The fat content in the grains of bread crops is 2 ... 6%. Its distribution in the grain is uneven, most of all in the embryo and alaron layer (in wheat buds up to 14%, rye and barley up to 12.5, corn up to 40, oats to 26, millet up to 20%). If there is a large amount of fat in the flour, it can harde. To improve the quality of flour in corn, before a brushes, they are removed in Ryzhev, from it, oil used on the food-stem and therapeutic goals. Fats of plant origin on consistency are liquid, since they consist mainly of unsaturated fatty acids - olein-olein, linoles and leb, with one, two or three double bonds.

3ol is part of the grain in the form of mineral, or ash, substances (phosphorus, potassium, magnesium, calcium, sodium, iron, cream, sulfur and chlorine). In very small quantities there are mar-garnets, zinc, nickel, cobalt, etc. These elements are part of various organic compounds and are in the form of salts and acids.

The ratio between elements in the composition of grain ash in different cultures is different. For example, in the grain of oats and militia, silicon is meaningful more than in wheat grain. The main part of the mini-rally is phosphorus, potassium and magnesium. In the ash, the zer-on wheat contains phosphoric acid (about 50% of the mass of ash), potassium oxide (about 30%), somewhat less - magic (about 12%) and very little calcium (about 2.8%).

Grain and produced products - the most important source of minerals for humans. With a complex oil, the prevailing part of the ash moves into bran, so the better the flour is separated from the bran, the less as an ash in it.

The fiber is the main part of the shells, a higher content of it is marked in the grains of film crops having a flower-release of scales, and at the holoper - in the fruit sheath. The content of fiber depends on the size of the grain. In large grains, the fiber is less than in the shallow.

Pigments (porphyrins, carotenoids, anthocyans, etc.) are also present in the grains of bread cereals, they give it one or another coloring.

Enzymes - organic compoundswho play an important role in rendering nutrients Seeds in a digestible form, for example, amylase, splitting starch, lipase - fats, etc.

In the complex and diverse chemical composition are necessary for normal life and livelihood. In the grains of bread cereals, the Vi-Tamines A1, B1, B2, C, D, RR, E, etc., in the absence or lack of them, the metabolism is violated in the body, may develop abroad - avitaminosis.

Grain structure

Outside, the grain is covered not only by seed peel, but also against the fruit sheath - by the fruit. Such a seed (Fig. 1) is called a grain, or grain. The main part of the grain is filled with a white mild mass (endosperm) representing the supply of nutrients. A germ fitted to the endosperm, consisting of a root with a root case, kids with leaves, a stalk and a shield - the only seedlus of the embryo. Among the germinal leaflets of the tieney is the cone of the rise of the stem. The upper germinal leaflets of the kidnings reliably protect the increasing cone from damage during the germination of a young stem through a dense layer of soil.

Fig. 1. The structure of the wheat grain: 1 - the ocoloblodnik compared with the skin; 2 - endosperm; 3 - alarium layer; 4 - germ; 5 - root; 6 - tieney; 7 - stalk; 8 - shield; 9 - Cone of the rise

During the germination of grain due to the activation of enzymatic processes, endosperma is discharged. The outer cells of the shield bordering with endosperm are lengthened and like the roots penetrate its nutrient medium, from where they suck the necessary food to grow the embryo. In the central part of the endosperma there are parenchymal cells with a large number of starchy grains, in the outer part there are square cells of the alarium layer, in which spare proteins in the form of alaric grains are deposited.



Inside the grain grain cereals, three main parts are clearly visible: shell, endospermand germ(Fig. 1). Since the grain is a fruit, then the outer part of the shell is called fruit sheath.She is two-layer. Under her there are two layers seed shell. Film grains, besides listed, there are so-called piece shellwhich is a flowering scales.

Germdifferentiated on various parts - the fourth plants. To the endosperma is adjacent shield- The only seedlings of bread cereals. Its function is to ensure the germ nutrients. At the bottom of the embryo are located primary (germinal) Fur in the form of small tubercles. Above is located Primary stem. He ends kidneyCovered with cap apparel leaves.The embryo in wheat, rye, barley, triticale is 2.0-2.5%, oats - 3.0-3.5%, and the corn is 10% of the mass of the grain.

IN endosperm (see Fig. 1) distinguish the outer ( aleron) layer, directly adjacent to the shell of grain, and internal mathematical part.

Aleron layer usually consists of one row of cubic cells. They contain dark yellow aleron grains, which are solid sediments of spare proteins. Barley has 3-5 rows of such cells. The share of the alaron layer, an average accounts for 6-8% of the mass of the grain.

Under alaron layer is puffy part of the endospermarepresented by cells filled with starch grains, and in the intervals between them protein substances are distributed. On the mildery part accounts for up to 85% of the mass of the grain.

Shells protect the grain from exposure to external conditions, damage to mushroom diseases. What they are thicker, the more bran when the grain grinding. Typically, shells account for 5-7% of the mass of the grain.

The internal structure of the grain is better to study under a microscope using ready-made, tinted drugs of longitudinal and transverse sections through wheat grain. Longitudinal cutting of the zenchki drucribe in the working notebook.

Structure of plants

Consider briefly features of the structure of plants of grain breads (Fig. 2). An adult plant is clearly visible: root system(urine), stems with leaves and generative organs (Colosums, panicles, cobs).

In germination of the grain, germ, or primary, roots are formed, then nodal, or apparent roots appear from underground stroke nodes.

Stem It is a solomine, consisting of 5-7 intercosals in almost all breads of the family of mattle, except corn and sorghum. In the latter, the amount of intersals can range from 12 to 20 or more, and the Solvin inside is filled with loose parenchym (the remaining bread is mainly a full solo).

Recalcute the number of intersals and make sure it coincides with the number of leaves. The more leaves, the time or hybrid is later.

Sheetconsists of a sheet plate and sheet vagina. At the base of the leafy vagina at its edges Form ears,and from the inside - tongue.

Socuagementwheat, rye, triticale and barley - spars, oats, millet, sorghum and rice - a mockery, and the corn has two inflorescences - a mockery (male) and pillage (female).

Earit consists of a crankshaft, on the protrusions of which the spikes are sitting. Parties spicy rod, where the protrusions are placed, are called facial, and where they are not - side.

Fig. 2. The scheme of the structure of wheat plants: 1 - roots;

2 - intercourse of the stem; 3 - node; 4 - leaf vagina; 5 - plate sheet; 6 - ears; 7 - tongue;

8 - spacing (inflorescence)

Panicleconsists from the central axis with nodes and intersticesAnd in the nodes of mutters are sideways. They can also branch, resulting in a branch of the first, second and subsequent branches.

At the ends of the branches sit spikelets.In each of them from one to several flowers and two sparking scales.

W. flowerthere is Lower (outdoor) and upper (internal) flowering scales.To the first of them attached Ostostial forms.

Pestle with the upper umbrella, one inverse seed and two-sighted filament, as well stychkin (Rice - six, the remaining cultures of the first three groups) are located between the flowering scales. At the base of the latter, you can see two small thin films called lodikule (Lodicule.). During the flowering period, they swell and open flower.

Fetus Grain Breads Family Matlikovaya, as you have already noticed, is called grainAnd buckwheat (Buckwheat family) is a triangular nut.

Several later, you consider in more detail the features of the structure of all components of grain crops.

Control questions

1. What subfamily is divided by the Mattilic family (Roaceae)?

2. What crops relate to the submenses of mint-shaped and projections?

3. At what ends of the grain is the embryo and a hokholok?

4. What is the difference in length, width and thickness of grain?

5. How are the grains differ in the nature of the surface, the insertion, color, form, of the film, the Khokholku?

6. What are the distinctive signs of breads I and II Group?

7. What does the anatomical structure of the grain look like?

8. What major parts are the plant?

10. What is the difference between the structure of the stem corn and sorghum from other grain crops?

11. What can be detected at the place of transition of the sheet vagina in sheet plate?

12. What are the generative bodies of grain crops?

13. What is the distinguished by the structure of the spoze and belties?

14. What is the locomotive and what is his role?

14. What is the name of the fruit of grain breads of the family of mint and buckwheat (family buckwheat)?

Summary of other presentations

"Determine the conditions for seed germination" - the distance between the tags is increasing. Development of the embryo. Terms of germination of seeds. Tags. He began to appear root. Growth. Research. Root zones. Side roots. Day. Seeds with water. Seaming seeds in favorable conditions. Sunflower oil. Root hairs. The structure of seeds of dietary plants. The conditions for germination of seeds and the development of the embryo. Seeds remained unchanged. Conditions for germination of seeds.

"Features of the structure of seeds" is the structure of seeds of dicotyledan and monocotyledonic plants. Testa. Covered plants. Trees. The smallest seeds. The most durable seeds. The supply of the nutrient. Features of the structure of seeds. The structure of the bean seed. Medicinal seeds. Get acquainted with the structure of the seed. Evaluation. Seed. Application form "Rate a lesson." The structure of the wheat grain. Self large seeds. The structure of plant seeds. Comparison.

"Seeds of flowering plants" - the plants of digestive and monocoons. Seed and its importance in the life of the plant. Test. The structure of the bean seed. Seed and its structure. Interview. External structure seed. The inner structure of the bean seed. Flower plant organs. Variety of embryos. Sleeps as a totality of the main root and the main escape. The structure of the fetus of wheat. All plants consist of cells. Power supply of nutrients. The structure of the wheat grain.

"The structure of the seed" is the internal structure of the bean seed. Fruit wroll. Fruits of coconut palm. Plants with lots of seeds. Bean seed at the beginning of germination. The structure of seed is ash. Flower plants. Divorous plants. Seeds monofilating. Monocoan plants. Crested seeds. Coconut palms. The structure of wheat seed. Ants. Frames of ripe box. Parachutics from hairs. Plants. The structure of the bean seed.

"Seed and its structure" - seed and its structure. Seed structure. Wheat. Seed. Swords. Studying the structure of the bean seed. Bean seed. Sinwen. Security Instructions. I do not believe. Progress.

"Laboratory work" Seed structure "" - consider dry and swollen seed of beans. The structure of the bean seed embryo. Insert the missed words. Bean seed. Seed structure. Studying the structure of the seed. Bean seeds. Restore the logical chain. Compare seed beans with wheat grain. Appearance seed. Germ. Grain of wheat. The structure of the bean seed.