The structure of the grain of wheat: what is the seed covered with, what parts does the germ consist of

Wheat is the most important grain crop, the seeds of which are characterized by a special structure. Its grain is used for the production of flour, pasta and bakery products. It is also used as feed for livestock. Protein, carbohydrate and enzymatic characteristics are of the greatest value. The structure of a grain of wheat is characterized by a number of unique features.

What is this

A caryopsis is a simple, dry one-seeded fruit that has a thin pericarp. The strong pericarp has a leathery structure and adheres tightly to the seed coat, growing together with the seed near the base.

A caryopsis is understood as a paracarp fruit. This is due to its formation from the paracarpous gynoecium. Some cereals form bare grains. This is what wheat looks like. However, it is devoid of scales or accessory fragments.

Structure of grain and seed

Many farmers are interested in what parts the grain consists of. Its structure is based on the endosperm, which is the core of the mealy structure. In the center are large cells of irregular shape. As you move away from the center, the cells become rectangular. Cellular structures contain proteins that form a continuous system with starch granules.

Shells

Shells are characterized by protective properties. Naked varieties are supplemented with 2 shells. On the outside is the pericarp, which is formed from the tissues of the ovary. The pericarp has 3 layers, which are formed by thick-walled cell structures.They are hollow inside. Cells are similar in structure to bricklaying. This arrangement increases the density of the shell and helps it withstand mechanical damage.

The shell of the seed consists of the walls of the kidney. It includes several layers of small cellular elements of irregular shape. There is a dye in the center that gives the seed its color.

In appearance, the structure of the seed is similar to a cylinder with a pointed top and bottom. It is characterized by a yellow-gold color and a dense structure.

Endosperm

Endosperm resembles an ordinary grain, which has a starchy structure. In its central part dense and uneven cells are located. As they move away from the center, they become smoother.Inside are protein elements, which are an integral system with starch granules.

This part is covered with an aleurone layer on the outside. Its cells have a different composition and are more like a cube. In structure, this part is denser and clearer.

Wheat Germ

According to the structure, the wheat germ consists of the following components:

• roots;
• apical meristem;
• kidney;
• stalk.

It is possible to study the structure of a grain germ only with a magnifying glass. The cotyledon is a thin plate that adheres to the endosperm and includes aleurone cells. The structure of the parenchymal fragment of the scutellum includes porous membranes.

In the center of the cotyledon is a line, or strand. This fragment connects to the bundle of radicular vessels in the area of the kidney base. From below, the shield is connected to the fabric of the coleoriza.

Outside, the cotyledon is covered with secretory cells, or epithelium. During the germination phase, these cellular elements produce enzymes that break down complex nutrients into simpler elements.

The shield creates a ledge at the top of the embryo. It closes the kidney from damage. Below is the epiblast - an organ that absorbs moisture from the soil during germination, transferring it through the vessels.

With the help of the apical meristem, the development of the sprout from the embryo is ensured. It produces new cellular elements.

Growth bud includes 3 leaf embryos. At the same time, only two develop, while the third resembles an arcuate roller. Outside, the kidney is covered with coleoptile. This element protects the seed from damage during the growing season.

There is a central root in the coleoptilary node. Also there are 1-2 pairs of additional ones. They are covered with films of calyptrogen. The outer part of the central root includes a dermatogen. During germination, it transforms into an epiblema. The next layer, the periblem, develops into the primary crust.

Chemical composition of the germ

In 1 kilogram of wheat germ there are the following components:

• 150 milligrams of vitamin E;
• 19 milligrams of vitamin B1;
• 12mg each of vitamins B2 and B6;
• active enzymes;
• positive ash, micro, macro elements.

The mass fraction of the embryo is 2-3%. Wheat proteins contain important acids. In wheat oil, the main components are linoleic and oleic acids. They also contain alpha-tocopherol, carotenoids, sterols.

Nutrients are constantly moving from culture to ovule. Due to this, a large number of nutrient compounds accumulate in the endosperm. Then the embryo is completely separated from the seed stalk, and useful elements fall into ripe fruits. The seed dries out, losing moisture. As a result, the peel becomes firm and surrounds the new embryo.

Substances contained in grains

Stocks of useful elements in the grain are present in the endosperm. Its outer layer, which is adjacent to the shell, includes grains of aleurone, which contains many nitrogen compounds. Beneath the endosperm are cells that contain starch.

Wheat grains contain the following components:

• 80% starch;
• 2% sucrose;
• 15% protein;
• 0.8% body fat;
• 1.5% Pentosan;
• 0.5% ash;
• 0.12% fiber.

Layers of the endosperm have differences in protein levels. From the center to the outer parts, its volume varies from 7 to 16%.

Energy Properties

Wheat contains many useful elements, most of which are concentrated in the structure of the endosperm. A special function is performed by the outer layer containing aleurones with a high nitrogen content.

Wheat contains many minerals and amino acids. It is of great importance for the body, as it saturates it with nutrients and energy.

Benefits of wheat

Wheat grains include 3 main components - germ, shells, endosperm. Each of the fragments contains a special set of components that favorably affect the functioning of the body.

Wheat has unusual properties. It includes nutritional components, the main part of which is carbohydrates. It also contains protein, which is required by the human body as a material for building new cells.

Wheat also includes vitamins A, E, B, D. There are many amino acids in it. Together, these elements can improve the state of immunity and have a positive effect on metabolic processes. They improve he althy hair growth and skin condition.

In addition, wheat grains include minerals, folic acid, carbohydrates. Folic acid has a positive effect on brain function, normalizes the functions of the nervous system and improves the condition of internal organs.

Wheat grains have a unique structure. They include several key components and contain many valuable substances that are beneficial to the body.

Recommended