Chemical composition and nutritional value of different types of flour. Characteristics of the composition and calorie content of wheat flour of the highest grade, as well as the use of this baking product in cooking Wheat flour solids

07.12.2020

The chemical composition of flour can vary greatly depending on the chemical composition of the grain, on the variety and yield of flour.

In turn, the chemical composition of grain to a certain extent depends on the characteristics of the type and variety of wheat or rye. Soil-climatic, weather and agrotechnical conditions for growing wheat and rye also affect the chemical composition of grain, often much more than varietal characteristics.

The chemical composition of different types of flour from the same batch of grain varies significantly and naturally.

In table. Table 3 shows the values of the content in individual varieties of baking wheat flour: water, proteins, fats, carbohydrates, fiber and ash, minerals, vitamins and the most deficient in bread essential amino acids (lysine and methionine).

The data given in table. 3 allow us to note that the content of nutrients that determine the nutritional value of flour (proteins, deficient amino acids, minerals and vitamins contained in grain and flour) is naturally associated with the yield of individual flour varieties: the higher the yield of flour, the more of these substances. The content of these substances is the lowest in premium wheat flour and seeded rye flour. Their content is highest in wholemeal flour.

STANDARD FOR TESTING METHODS FOR FLOUR

GOST for wheat flour provides for the determination of such quality indicators as color, smell, taste, content of mineral and metal-magnetic impurities, humidity, ash content or whiteness index, grinding size, quantity and quality of raw gluten on the IDK device with an indication of the quality group.

GOST par rye flour provides for the determination of such indicators as color, smell, taste, mineral impurities, humidity, ash content, whiteness, falling number, fineness, metal magnetic impurities, infestation and contamination with pests.

The methodology for the above definitions is described in GOSTs, as well as in manuals and manuals on the technical and chemical control of bakery production.

BAKERY PROPERTIES OF WHEAT FLOUR

Good wheat bread should have sufficient volume, regular shape, normally colored (brown) crust without

Table 3 The chemical composition of flour (reference book - "Chemical composition of food products", 2000)

	Nutrients Nutrients
																		Aminoki-
Flour								Minerals, mg%		vitamins,	mg%		slots,
bakery							Ash,											M1	%
	Water, %	Proteins, %	Fats, %	Mono- and disaccharides	Starch, %		%		To	Sa	Mg	R	Re	E	AT,	in,	RR	in,	lysine	methio-nin
wheat,
grade:
higher	14,0	10,3	1D	0,2	70,4	3,5	0,5						1,2	1,1	0,17	0,04	1,2	0,17
first	14,0	10,6	1,3	0,5	67,1	5,8	0,7						2,1	3,05	0,25	0,08	2,2	0,22
second	14,0	11,7	1,8	0,9	62,8	7,7	1,1						3,9	5,37	0,37	0,12	4,6	0,5
peeling	14,0	11,5	2,2	1,0	58,3	11,3	1,5						4,7	5,5	0,41	0,15	5,5	0,55
Rye:
seeded	14,0	6,9	1,4	0,7	65,6	10,8	0,6						2,9	1,1	0,17	0,04	1,0	-
peeling	14,0	8,9	1,7	0,9	60,9	12,4	1,2						3,5	1,9	0,35	0,13	1,0	-
wallpaper	14,0	10,7	1,9	1D	57,4	13,3	1,6						4,1	2,2	0,42	0,15	0,2	-

gaps and cracks, elastic crumb with fine, thin-walled and uniform porosity. Bread should be tasty and fragrant. The lighter the crumb of a certain type of wheat bread, the higher it is valued by the consumer.

Wheat flour of good baking quality allows, with proper management, technological process receive bread that meets the above requirements.

The baking quality of wheat flour is mainly determined by the following properties:

1) gas-forming ability;

2) the ability to form a dough with certain
rheological properties - the power of flour;

3) the color of flour and its ability to darken in the process of making bread from it.

The size of the flour particles is also significant.

Examination of flour quality.

Purpose of work: assessment of the quality of wheat and rye flour.

Flour is a powdered product with a different granulometric composition, obtained by grinding (grinding) grain. Flour is used for the production of bakery, confectionery and pasta products.

Flour is divided into types, types and varieties.

Types of flour differ depending on the culture from which it is developed. So, flour can be wheat, rye, corn, soy, barley, etc. Wheat flour is the most important, accounting for 84% of the total flour production.

flour type are distinguished within the type of flour, depending on the intended purpose. So, wheat flour can be bakery, for pasta, confectionery, ready for consumption (cooking), etc. In production certain type flours select grain with the necessary physical, chemical and biochemical properties. For example, for the production of pasta flour, durum or high-glass soft wheat is taken and flour is obtained, consisting of relatively large homogeneous endosperm particles. In the production of baking flour, soft glassy or semi-glassy wheat is used and finely ground flour is obtained, from which it is easy to make soft, moderately elastic dough, to obtain a high yield of lush, porous bread.

Rye flour is produced in only one type - baking.

Flour grade distinguished within each type. The division into varieties is based on the quantitative ratio of endosperm and shell particles. Flour of the highest grades consists of particles only of the endosperm. Inferior grades contain a significant amount of shell particles. Varieties differ in chemical composition, color, technological advantages, calorie content, digestibility, biological value (Table 2.1).

Table 2.1. The chemical composition of wheat flour of different varieties

Content per 100 g of product	Flour grade
higher	first	second	wallpaper
Water, g	14,0	14,0	14,0	14,0
Proteins, g	10,3	10,6	11,7	11,5
Fats, g	1,1	1,3	1,8	2,2
Mono- and disaccharides, g	0,2	0,5	0,9	1,0
Starch, g	68,7	67,1	62,8	55,8
Fiber, g	0,1	0,2	0,6	1,9
Ash, g	0,5	0,7	1,1	1,5
Minerals, mg
Na
To
Sa
mg
R
Fe	1,2	2,1	3,9	4,7
Vitamins, mgyo
β-carotene		Traces	0,01	0,01
IN 1	0,17	0,25	0,37	0,41
IN 2	0,04	0,08	0,12	0,15
RR	1,20	2,20	4,55	5,50

Nutritional value of wheat flour. Wheat flour of all types and varieties has some general properties, due to the properties of wheat grain. These include characteristics proteins, carbohydrates, enzymes and other substances that make up wheat flour, as well as the structure of cells, starch grains, etc.

Wheat flour proteins mainly consist of insoluble hydrophilic proteins - glutenin and gliadin (in ratios 1:1.2; 1:1.6). Other proteins (albumins, globulins, nucleoproteins) are found in a small amount mainly in flour of lower grades. The most important property of glutenin and gliadin is the ability to form an elastic mass - gluten - in the process of swelling. The yield of raw gluten when washed from flour of different varieties is 20 - 40%, and the share of dry matter accounts for about 1/3 of the mass of raw gluten. The composition of dry gluten includes (%): protein -5 - 9, carbohydrates - 8 - 10, fat and fat-like substances - 2.4 - 2.8, minerals - 0.9-2.0.

During kneading, gluten forms a continuous phase of wheat dough, retains carbon dioxide during fermentation, thereby ensuring good leavening of the dough, and during baking, gluten denatures, coagulates, releasing excess water, and fixes the porous structure of bread. In the production of pasta, due to the presence of gluten, wheat dough has high plasticity and cohesion, and it is possible to produce pasta of various shapes. When drying pasta, gluten hardens, fixes the shape of the pasta and determines their glassy consistency.

For the quality of flour, not only the amount of gluten is important, but also its elasticity, resilience and extensibility.

Carbohydrates in wheat flour are mainly represented by starch. Its amount fluctuates between 65 - 80%. Wheat starch, if it consists of whole, undamaged grains, swells well, gives a viscous, slowly aging glue erased. Starch during saccharification is a source of sugars used in the fermentation of the dough.

The sugars of benign wheat flour are mostly represented by sucrose - 2-4% and to a lesser extent by directly reducing sugars (maltose, glucose and fructose) - 0.1-0.5%. The amount of sugar is an important factor in the baking qualities of flour. Due to the fact that the sugars contained in wheat flour are not enough for fermentation, the activity of flour saccharifying enzymes is of great importance. The process of sugar formation proceeds in flour from high-grade grain according to the scheme: starch - glucose and fructose phosphates - sucrose - invert sugar. In flour from defective grains (self-heating, sprouted), starch is hydrolyzed mainly under the action of the enzymes amylase and maltase with the formation of a significant amount of dextrins, maltose and glucose, therefore, such flour is characterized by a markedly increased content of dextrins and directly reducing sugars.

Wheat flour, especially low grades, is an important source of minerals (Ca, Fe, P and some trace elements) and water-soluble vitamins (B l B 2 , PP). The content of ballast substances - fiber and pentosans is small and depends on the type of flour: in the highest grades, the amount of fiber is 0.1 - 0.15%, pentosans - 1 - 0.15; in the lowest - 1.6 - 2 and 7 - 8%, respectively.

Nutritional value and properties of rye flour largely due to the chemical and tissue composition of rye grain, the properties of its constituent substances. A distinctive feature of rye flour is the presence in its composition of a large amount of water-soluble substances (13-18%), including soluble proteins, carbohydrates, and mucus. Rye flour contains slightly less proteins than wheat flour - an average of 10 - 14% (Table 2.2).

Table 2.2. The chemical composition of rye flour

Content, mg/100 g of product	Flour grade
seeded	peeling	wallpaper
Water	14,0	14,0	14,0
Squirrels	6,9	8,9	10,7
Fats	1,4	1,7	1,9
Mono- and disaccharides	0,7	0,9	1,1
Starch	63,6	59,3	55,7
Cellulose	0,5	1,2	1,8
Ash	0,6	1,2	1,6
Minerals:
Na
To
Sa
mg
R
Fe	2,9	3,5	4,1
Vitamins:
β-carotene	Traces	Traces	0,01
IN 1	0,17	0,35	0,42
IN 2	0,04	0,13	0,15
RR	0,99	1,02	1,16

Under normal conditions, rye flour proteins do not form gluten, which can be separated from other substances. The so-called intermediate protein is capable of forming a certain amount of gluten, but this is of no practical importance, since gluten is not washed off from rye flour. Rye flour proteins contain water- and salt-soluble fractions capable of unlimited swelling. The total amount of soluble and soluble proteins reaches 50-52% of their total content; with soluble carbohydrates and mucus, they form viscous colloidal solutions that make up the continuous phase of rye dough.

Rye flour proteins have a favorable amino acid composition; compared to wheat flour proteins, they are relatively rich in amino acids such as lysine, histidine, valine, leucine.

The amino acid tyrosine is involved in enzymatic oxidation and the formation of dark-colored substances - melanins. For this reason, and also due to the interaction of amino acids with reducing sugars and the formation of melanoidins, rye flour of all varieties gives a darkening dough and bread with a dark crumb and crust.

Carbohydrates make up 80 - 85% of the dry mass of flour and are represented by starch, sugars, pentosans, mucus and fiber.

Starch in rye flour, depending on its variety, contains from 60 to 73.5%. For the most part, it consists of large lenticular-shaped grains. Rye starch has the lowest gelatinization temperature (46 - 62 ° C) and the ability to produce a viscous, slowly aging paste. This property, combined with the overall high content of soluble substances, results in a soft texture and slow staleness of rye bread.

Sugars in rye flour are in the amount of 6 - 9%. They contain few reducing sugars - 0.20 - 0.40%, represented by glucose and fructose, a lot of sucrose - 4 - 6% of the mass of flour (or 80% of all sugars), as well as maltose, raffinose and trifructosans.

Fiber in rye flour, despite the presence of a relatively large number of shell particles (there are 20–26% in wholemeal flour), is about the same as in wheat flour (0.4–2.1%, depending on the variety). This is due to a significantly lower fiber content in the shells and aleurone layer of rye.

A feature of rye flour is the presence of pectin substances, the amount of which is higher than in wheat flour (Table 2.2).

Fat - there is little of it in rye flour - 1 - 2%. Linoleic (43%), palmitic (27%), oleic (20%) acids predominate in its composition, there is linolenic acid (4%); also contains lecithin (9% of fat mass) and tocopherols - vitamin E (258 mg%), which are natural antioxidants, so rye flour fat is highly resistant to rancidity. Coloring substances of flour are represented by flavone pigments, anthocyanins and chlorophyll.

Quality expertise flour is produced according to the following indicators: organoleptic, technical, physico-chemical and technological. General quality indicators characterize the freshness and good quality of flour - color, smell and taste.

flour color mainly due to its type and variety, i.e. the color of the grain and the content of endosperm and bran particles in the flour. It is determined visually in a dry or wet sample or analytically - using special instruments - photoanalyzers.

Flour of each type and grade has its own color: grits - cream, wheat flour of the highest grade - white, the first - white with a yellowish tint, the second - white with a clear brownish tint, wallpaper - with a darker brownish tint, seeded rye - white, slightly bluish, rye peeled and wallpaper - white with a distinct gray or brownish tinge, etc. Abnormal changes in the color of flour can be caused by an increased content of bran, improper grinding of flour, the presence of impurities (maryannik, smut, etc.) that give the flour unusual dark shades, as well as its spoilage and the formation of dark-colored substances (melanoidins) in it.

The smell of flour usually determined in a small (5 - 10 g) amount of flour slightly heated by breathing. Fresh flour has a specific mild pleasant smell. There is no mustiness, moldy smell and any foreign smell. The appearance of an odor that is not characteristic of normal flour can be caused by different reasons: rancidity of fat, the development of fungi of the genus Penicillium, other molds (aspergillus, mucor, etc.). In addition, musty and moldy odors result from the adsorption of odorous substances when flour is stored in damp, poorly ventilated areas. Foreign odors (wormwood, garlic, sweet clover) can be caused by the ingress of the corresponding odorous impurities into the flour, the adsorption of odorous substances when packing flour in dirty containers, as well as during storage in warehouses or transportation in wagons with foreign odors.

Taste determined by chewing a small (2 - 3 g) amount of flour Benign flour has a mild pleasant, slightly sweet taste. Flour is not allowed sour, bitter or obviously sweet taste, as well as the presence of foreign flavors. Changes in taste can be caused by spoilage of flour (sourness or rancidity), the production of flour from defective grains. Spoiled grain gives a sour or bitter taste, sprouted - sweet, foreign impurities - wormwood, mustard, briar. Flour of any kind, when chewed, should not give a crunchy feeling on the teeth. The crunch is caused by the ingestion of crushed mineral impurities into the flour.

The indicators determined by analytical methods include moisture content, ash content, grinding fineness.

Humidity, i.e. the amount of free and physically bound water, expressed as a percentage of the mass of the product. Usually, flour made from high-quality grain and stored under favorable conditions has a moisture content in the range of 13-15%. The increased humidity of flour, which occurs in cases of processing substandard grain, improper conduct of the technological process (washing and conditioning of grain) or as a result of storing flour in conditions of high relative humidity (above 70-75%), adversely affects the quality of flour. At high humidity free water accumulates in it, activating the activity of enzymes and contributing to the rapid development of microflora, which sharply reduces the shelf life and often leads to spoilage of flour. In addition, increased moisture content of flour significantly affects the properties of proteins and starch, reduces its ability to swell and impairs baking properties.

Quantity and quality of raw gluten determined to characterize the baking or pasta properties of wheat flour. This indicator is provided in the standards and quality norms for flour.

Gluten is a protein jelly that remains after washing the dough with water and removing starch, fiber and water-soluble substances from it. The gluten-forming proteins are concentrated in the peripheral parts of the endosperm; therefore, less gluten is formed in the premium flour than in flour of I and II grades. It should be borne in mind that raw gluten contains from 60 to 75% water and its yield depends not only on the protein content in the flour, but also on its ability to absorb and retain more or less water. If the gluten is dried and weighed, it is possible to determine the content of dry gluten, and by the ratio of the mass of raw gluten to the dry mass, its water absorption capacity. For gluten of normal quality, this value is 2.5 - 3%.

For wheat flour different types and grades, limit norms for the yield of raw gluten (%, not less than) are set: for baking flour: semolina - 30, premium - 28, first - 30, second - 25, wallpaper - 20; for pasta flour from durum wheat - 30 - 32, from soft - 28 - 30.

The washed gluten is evaluated organoleptically by color (light, dark), elasticity and extensibility.

According to the current standard for test methods, flour gluten, like grain gluten, is divided into three groups:

I - good - elastic, normally extensible (up to 10 cm or more);

II - satisfactory - less elastic, different extensibility;

III - unsatisfactory - low-elasticity, strongly stretching, spreading, crumbling.

Gluten in bread flour should be of good or fair quality, and pasta flour should be of good quality.

Unsatisfactory in quality is recognized gluten, which spreads when in water. The gluten of this group is usually dark gray or brownish in color.

Ash content in terms of dry matter, it serves as an indirect indicator of the varietal affiliation of flour of all kinds.

The determination of the flour grade by its ash content is based on the uneven distribution of minerals in the tissues of cereal grains. For wheat (on average), mineral substances (%) are distributed as follows: ash content of the endosperm - 0.4, aleurone layer - 10, shells - 4, germ - 5; for rye: ash content of endosperm - 0.5, aleurone layer - 6.7, shells - 3.7, germ - 4.5. Therefore, the highest grade flour has an ash content of 0.4-0.6%, and as the grade decreases and the number of bran particles increases, the ash content increases, reaching an ash content in wholemeal flour close to the ash content of the whole grain (1.9 - 2%).

Grinding size determined in a sample isolated from an average sample weighing 50 g. To determine the fineness, sieves are selected that are established by regulatory documents for the corresponding type of product.

A sample of the product is poured onto the upper sieve, covered with a lid, a set of sieves is fixed on the sieving platform and the sieving is switched on. After 8 minutes, the sifting is stopped, the sieve shells are tapped, and sieving is continued again for 2 minutes. At the end of sieving, the remainder of the upper sieve and the passage of the lower sieve are weighed and calculated as a percentage of the mass of the sample taken.

The fineness of grinding determined and normalized in this way gives only an approximate idea of the degree of grinding of the product. Current regulations limit the amount of coarse particles and guarantee a known minimum of fine particles. Norms for all types and grades, except for grains and pasta flour, the degree of flour grinding is not limited. The passage through any thick sieve can be increased to 100%, and the particle sizes are reduced to a high degree of dispersion. Therefore, different grades of flour - the highest, the first, the second - in terms of the degree of grinding in some cases differ little from each other.

Different grain size of flour is closely related to its properties - water absorption and sugar-forming ability, swelling ability and other indicators. Grain and pasta flour is characterized by a reduced water absorption capacity, slowly swells and is capable of additional swelling. This process consists in the fact that when kneading the dough, substances swell on the surface of relatively large particles and, with a small amount of water used, a cohesive dough is formed, but then the moisture is absorbed by the internal colloidal system of particles and the consistency of the dough changes. The dough becomes more cohesive and dense. Coarse flour has a lower sugar-forming capacity. Such flour is best used for the production of pasta, where the minimum water absorption capacity, as well as the ability of the dough to additional swelling, makes it easier and cheaper to obtain high-quality pasta.

For baking flour, increased fineness is undesirable, since the yield of bread, except for some rich products, decreases, the process of dough formation slows down, bread from it is obtained in a small volume and with a coarser porosity.

Bread flour for retail trade has the best properties if it consists of sufficiently small (70-100 microns) homogeneous particles with a grainy structure. Such flour has a sufficiently high water absorption capacity, the dough from it is elastic, well retaining its elastic properties. Sugar-forming ability is also close to optimal.

Heavily crushed (dusty and ground) flour has undesirable properties: an excessively large water absorption capacity (the dough from it quickly liquefies, the bread is reduced in volume, with a dense, often crumbly crumb and a dark crust). Hearth bread made from such flour usually turns out vague. The fraying of flour has a particularly strong effect on its enzymatic activity. Mechanically damaged starch grains are subject to more rapid action of enzymes, which causes its rapid liquefaction and saccharification. Such starch is saccharified several times faster than normal medium grains.

The content of the metal-magnetic impurity in flour is limited by special regulations. Metal particles get into the flour in the form of grains of slag, ore, rust in case of poor grain cleaning or unsanitary condition of the mill. Particles of cast iron and steel get into the product as a result of wear of rollers, steel screens, metal gravity flows. Most of the metal is extracted in mills using magnetic devices installed along the path of the product, but a small part of it remains in the flour. The amount of magnetic impurities in flour is determined by extracting the metal from a 1 kg flour sample. The metal is extracted using strong magnets - magnetic horseshoes or on a special apparatus - a ferroanalyzer. The isolated metal impurity is weighed on an analytical balance. In flour, more than 3 mg of metal-magnetic impurities per 1 kg of flour are not allowed. The size of individual particles of a metal-magnetic impurity in the largest linear dimension should not exceed 0.3 mm, and the mass of individual particles should not exceed 0.4 mg.

The content of harmful and grain impurities in flour is also normalized, but determined by analyzing the grain before grinding. The results of grain analysis are indicated in the documents on the quality of flour and flour is evaluated on them. The following limiting standards for the content of impurities (%) have been established: ergot, smut, mustard, briar - no more than 0.05, including mustard and briar - no more than 0.04; the admixture of heliotrope pubescent and trichodesma incanum is absolutely not allowed; cockle seeds - no more than 0.1; grains of barley, rye (in wheat) and germinated - no more than 4 in total, including germinated grains, the number of which is determined in the grain before cleaning - no more than 3.

Flour with a high content of harmful impurities is unsuitable for human consumption. Grain impurities, especially barley and sprouted grains, reduce the baking properties of wheat and rye flour.

Infestation of flour by pests(beetles and their larvae, butterflies and their caterpillars, as well as ticks) is not allowed according to the current rules and regulations.

To establish the infection, 1 kg of flour is sifted through sieves (varietal flour through a sieve No. 056, and wallpaper flour through two sieves No. 067 and 056). The passage through the No. 056 sieve is used to detect mites, and the residues on the No. 056 and 067 sieves are used to detect other pests, scattering the residue in a thin layer on the analysis board and carefully examining it.

Ticks in flour are difficult to distinguish and therefore they are detected indirectly. Five portions of 20 g each are taken from the flour that has passed through a sieve No. 056. Each sample is placed on the glass and lightly pressed with a piece of paper or glass to make the surface perfectly smooth. Then, after some time, the surface of the pressed flour is carefully examined. The appearance of swellings or grooves indicates the presence of mites.

Bulk yield and dimensional stability of bread set by trial baking. It is used in the evaluation of wheat flour, less often - rye.

For baking, 1000 g of flour is usually taken at a moisture content of 14% (or the mass of flour is brought to this moisture content); when kneading the dough, use 530 - 540 ml of water, 30 g of pressed yeast and 15 g of salt. The dough ferments for 160 minutes with 1 - 2 punches at 32°C. The finished dough is divided into three equal parts. Two are placed in iron molds, and the third is molded into spherical hearth bread. The dough is proofed (at 35 0 C and relative humidity 80%) to the maximum volume. The surface of the dough is moistened with water and baked at 225 - 230 0 C for 30 minutes.

After cooling (after 4 hours), the volumetric yield of bread and the ratio of the height of the hearth bread to its diameter are established. The volume is determined in a special device consisting of a vessel of a fixed capacity and a measuring cylinder equal in volume to it, filled with flax seeds or millet. Bread is placed in the first vessel, filled with flax seeds or millet flush with the edges, the volume of bread is determined from the remainder of the seeds in the cylinder, and then divided by the mass of flour (g) spent on baking this bread, and multiplied by 100; the result is a volumetric yield of bread (cm 3) per 100 g of flour. The hearth loaf is measured by determining its diameter and height, and the ratio of height to diameter H/D is calculated. According to the volume output of panned bread and the H/D ratio of hearth bread, the baking properties of the flour are judged.

There are many different test baking methods. One of them can be cited as an example: for high-grade wheat flour, the volumetric yield of bread is from 350 (for second grade flour) to 500 cm 3 (for premium flour), and the H / D ratio is from 0.35 to 0, 5 respectively.

Baked bread is used to determine taste, smell, color, crumb structure, porosity and other indicators.

Test baking also reveals flour contaminated with potato disease. To do this, one loaf is wrapped with wet paper or cloth and left for 24 hours. Then it is cut or broken. The appearance of lumps or threads of mucus in the crumb indicates that the flour is infected with potato disease.

Baking bread from rye flour due to the need to use sourdough and multi-phase dough management is used relatively rarely. They are usually replaced with kolobok baking: 50 g of flour is kneaded with 41 ml of water at room temperature, a ball (kolobok) is formed from the resulting dough and baked at 230 ° C for 20 minutes. Then the quality of the baked kolobok is determined. It has been established that the assessment of flour by the quality of the kolobok is quite close to its assessment by autolytic activity.

From flour of good quality with medium autolytic activity, a bun of the correct shape is baked, without noticeable cracks, with a fairly dry crumb. The content of water-soluble substances in the crumb - 23 - 28%.

Flour with reduced autolytic activity also produces a bun of regular spherical shape, but small in volume, very pale in color, with a dense and dry crumb. The content of water-soluble substances in the crumb is less than 23%.

When baking from flour with increased autolytic activity, the bun is flat, spreading, with cracks on the surface, with a sticky crumb. The content of water-soluble substances is more than 28%.

gas holding capacity- is determined simultaneously with gas-forming. It is characterized by an increase in the volume of dough during fermentation and is expressed either as a percentage of the volume of gas released, or as the ratio of the volume of fermented dough to the original volume.

Determining the gas-forming and gas-holding capacity is important. However, the results of this determination depend on many factors - yeast, test conditions, etc. In addition, the experience requires a lot of time. At the same time, the gas-forming ability of flour depends on its sugar-forming ability, and the gas-retaining ability depends on the quantity and quality of gluten and the elastic properties of the dough. For all these reasons, it is more reasonable to resort to the definition of the latter indicators.

Gas generating capacity determined in the following way: from the test flour (100 g) knead the dough with the addition of salt and yeast, place it in a cylinder and let it ferment for a certain time (5 hours) and under certain conditions (30 ° C), setting the amount of carbon dioxide released. This amount varies widely - from 1000 to 2200 ml or more.

Requirements for the quality of wheat baking and rye flour are given in table. 2.8 and 2.9 (applications).

In accordance with SanPiN 2.3.2.1078 - 01, the safety indicators for all types of flour are as follows (Table 2.3):

Table 2.3. Maximum content of hazardous substances in flour

Practical part

Laboratory analysis of flour for quality compliance with the standards of flour mills is carried out according to the scheme shown in Figure 2.1

Rice. 2.1. Scheme of flour analysis

Lesson 1. "Examination of the quality of wheat flour"

1. Determination of organoleptic indicators of flour __________________.

(type of flour)

Colour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .________________

Smell. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .________________

Taste. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ________________

2. Determination of moisture content of flour. Humidity is determined by drying the sample. To do this, a sample of 5 g of flour is placed in a weighing bottle with a ground lid, weighed on an analytical balance, and then placed in an oven for 50 minutes at 130 ° C, after which the weighing bottle is placed in a desiccator for cooling and weighed again. Humidity is calculated by the formula:

where m 1 is the mass of an empty bottle, g;

m 2 - mass of weighing bottle with wet yeast, g;

m 3 - weight of bottle with dried yeast, g.

When calculating the results, fractions up to 0.05 are discarded, and fractions equal to 0.05 or more are rounded up to 0.1.

Moisture determination method. . . . . . . . . . . . . . . . . ________________

Weight of an empty bottle, m 1, g. . . . . . . . . . . . . . . . . . . ________________

Bulk weight in wet flour, m 2, g. . . . . . . . . . . ________________

Weight of bottle with dried flour, m 3, g. . . . . . . .________________

Moisture content of flour, W, %. . . . . . . . . . . . . . . . . . . . . . . .________________

3. Infection determined by sifting 1 kg of high-quality flour through a wire sieve No. 056, wallpaper - through wire sieves No. 067 and No. 056. The residues on the sieves are analyzed for the presence of beetles, pupae, larvae. The passage of sieve No. 056 is used to determine mite infestation.

4. Grinding size of flour determined by sifting on a laboratory sieving a test portion weighing 100 g for sifting flour and 50 g for high-quality flour on sieves established by the standard. The residue on the upper sieve characterizes the presence of large particles in the flour, and the passage on the lower sieve characterizes the presence of small particles. Enter the results in table 2.5.

Table 2.4. Grinding size of flour _____________________

(type of flour)

Sieve	Residue on the sieve, g	Percentage of neither sieve, %

The result of the analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . _________________

5. Determination of baking power wheat flour on sedimentation sediment.

The determination method is based on the ability of flour protein substances to swell in weak solutions of lactic or acetic acids and form a precipitate, the value of which characterizes the amount of protein substances. In a 100 ml measuring cylinder with a ground stopper, graduated with a division value of 0.1 ml, add 3.2 g of flour, weighed on a technical scale. 50 ml of distilled water, tinted with bromophenol blue dye, is poured into the cylinder. Turn on the stopwatch (it is not stopped until the end of the definition). The cylinder is closed with a stopper and shaken for 5 s, sharply moving in a horizontal position. Get a homogeneous suspension. The cylinder is placed in a vertical position and left alone for 55 s. After removing the cork, pour 25 ml of a 6% solution of acetic acid. Close the cylinder and turn it over 4 times within 15 s, holding the stopper with your finger. Leave the cylinder alone for 45 s (up to 2 minutes by the stopwatch from the beginning of the determination). Within 30 s, the cylinder is smoothly turned over 18 times. Leave for the third time alone for exactly 5 minutes and immediately make a visual reading of the volume of sedimentation sediment to the nearest 0.1 ml. If a small part of the sediment floats, it is added to the main sediment. The established volume of sedimentation sediment (ml) is recalculated for flour moisture content of 14.5% according to the formula

where V y exp - actually measured value of sedimentation sediment, ml;

w m - actual moisture content of the studied flour, % for dry-air substance.

To assess the baking power by the amount of sedimentation sediment, the following approximate standards are recommended.

Table 2.5. Sedimentation sediment (ml) at different grinding sizes

Record in the laboratory journal:

Actual measured value of sedimentation sediment, V c.exp, g. .___________

Humidity of the studied flour, W, % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ___________

Installed volume of sedimentation sediment, V Y, ml. . . . . . . . . . . . . ___________

6. Quantity and quality of raw gluten.

A portion of flour 25 g is weighed on technical scales and placed in a porcelain mortar or cup and 13 ml of tap water is poured at a temperature of 16 ... 20 ° C. Flour and water are mixed with a spatula, getting a dough, which is then well kneaded by hand. Dough particles adhering to the cup and spatula are carefully collected (cleaned with a knife) and attached to a piece of dough.

After rolling the dough into a ball, place it in a cup and cover with glass for 20 minutes so that the flour particles are saturated with water, the proteins swell. Then the gluten is washed from starch and shells under a weak stream of tap water over a thick silk or nylon sieve, slightly kneading the dough with your fingers. At first, washing is carried out carefully, not allowing pieces of gluten to come off together with starch and shells, after removing most of the starch and shells, more vigorously Accidentally detached pieces of gluten are collected and attached to the total mass of gluten.

It is allowed to wash gluten (if there is no running water) in a basin or container containing at least 2 liters of water. Knead the dough in water with your hands. When starch and shells accumulate in the water, it is drained, filtered through a thick silk or nylon sieve, a new portion of water is poured and so on until the end of washing, which is established by the absence of starch in the water (almost transparent), flowing down when gluten is squeezed out. If the gluten is not washed out, the results of the analysis are recorded as "Not washable".

Having finished washing the gluten, it is squeezed between the palms, which are periodically wiped dry with a towel. At the same time, the gluten is turned out several times with your fingers, each time wiping your palms with a towel. Do this until the gluten begins to slightly stick to your hands.

The gluten is weighed, washed again for 2-3 minutes, squeezed again and weighed again. The washing of gluten is considered complete when the difference in mass between two weighings is not more than 0.1 g. The amount of raw gluten is expressed as a percentage of a flour weighing 25 g. Depending on the gluten content, several product categories are distinguished (Table 2.6).

The result of the analysis __________________________________________.

7. Determination of the quality of raw gluten. The quality of raw gluten is characterized by physical properties, extensibility and elasticity, color (light, gray, dark).

The extensibility of gluten is understood as its ability to stretch in length. To assess the quality of gluten by extensibility, 4 g of raw gluten is placed for 15 minutes in a glass of water at a temperature of 18 - 20 ° C. Further, taking a piece of gluten out of the water and squeezing it out, manually over the course of 10 s it is gradually stretched over the ruler into a tourniquet until it breaks, noticing how long the gluten has stretched. By extensibility, gluten is divided into: short - 10 cm, medium - extensibility 10 - 20 cm, long - extensibility more than 20 cm.

Under the elasticity of gluten is meant its ability to restore its original dimensions after it is stretched. The elastic properties of gluten mean resistance to the action of a compression load. For the determination of 4 g of gluten after exposure for 15 minutes in cold water at a temperature of 18 - 20 ° C is placed in the center on the instrument table of the pinetrometer. The working body of the pinetrometer is brought into contact with gluten, then it is loaded with 120 g. After 30 seconds, the load is removed and the amount of deformation is determined on the scale. When the deformation of the gluten is less than 37.5%, the quality of the gluten is very strong; at 37.5 - 55% - strong; 55 - 70% - average; 70 - 87.5% - satisfactorily weak, 87.5 - 100% - unsatisfactorily weak.

Record in the laboratory journal:

Weighing weight of raw gluten, g. . . . . . . . . . . . . . . . . . . . . . . . . . .___________

after the first washing, g. . . . . . . . . . . . . . . . . . . . .___________

after the second washing, g. . . . . . . . . . . . . . . . . . . . .___________

The amount of crude gluten,%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .___________

Gluten color. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .___________

Extensibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .___________

Elasticity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .___________

Flour, like grain, mainly consists of proteins and carbohydrates. These are the most important components of flour, on which the properties of the dough and the quality of products depend. The chemical composition of flour determines its nutritional value and baking properties. The chemical composition (average) of wheat flour depends on the composition of the original grain and the type of flour (Table 3.3).

When grinding grain, especially varietal grain, they strive to remove the shells and the germ as much as possible, therefore flour contains less fiber, minerals, fat and protein and more starch than grain. Higher grades of flour are obtained from the central part of the endosperm, so they contain more starch and less proteins, sugars, fat, mineral salts, vitamins, which are mainly concentrated in its peripheral parts.
The organic substances of wheat flour include proteins, nucleic acids, carbohydrates, lipids, enzymes, vitamins, pigments and some other substances; to inorganic - minerals and water.
Proteins play an important role in bread technology.
The protein content in wheat flour can vary widely (from 10 to 26%) depending on the wheat variety and its growing conditions. The protein substances of flour are mainly (80%) composed of prolamins and glutelins. The remaining proteins are albumins, globulins and proteids. Prolamins and glutelins of various cereals have specific composition and properties.
Wheat prolamin is called gliadin, and wheat glutelin glutenin. The ratio of gliadin and glutenin in wheat flour is approximately the same. Gliadin and glutenin are found only in the endosperm, especially in its marginal parts, so there are more of them in high-quality flour than in wholemeal flour. A valuable specific property of gliadin and glutenin is their ability to form gluten.
Gluten is formed when wheat dough is washed in water. Gluten contains 65-70% moisture and 30-35% dry matter, consisting mainly of proteins (90%), as well as other flour substances absorbed by proteins during swelling. The baking properties of flour depend on the quantity and quality of gluten. Flour contains an average of 20-35% raw gluten. The quality of gluten is characterized by its color, extensibility (the ability to stretch to a certain length) and elasticity (the ability to almost completely restore its shape after stretching). In gluten, the content of minerals is different than in the grain from which it is washed.
When washing gluten, some mineral substances are concentrated in it, for example, phosphorus, magnesium, sulfur. A special place is occupied by potassium, which is characterized by increased bond strength with non-gluten substances of the grain and, when washed, almost all of it remains in the grain residues. The total ash content of gluten is higher than that of grain. The content of iron, zinc and copper in gluten is much higher than in grain. For example, wheat grain contains 0.26% iron, gluten ash - 1.90%.
Large differences in the ash content of individual parts of the grain are used to control the yield (by grade) and the quality of wheat flour. According to the mass fraction of ash in wheat flour, one can judge the number of peripheral particles and the germ that have passed from the grain.
The composition of flour is dominated by carbohydrates. They take part in the fermentation of the dough.
Wheat flour contains various carbohydrates: monosaccharides (pentoses, hexoses), disaccharides (sucrose, maltose), polysaccharides (starch, fiber, hemicelluloses, cellulose, mucus). From simple carbohydrates highest value have hexoses - glucose and fructose. They are fermented by yeast during the fermentation of the dough and participate in the reaction of melanoidin formation during baking.
The lower the grade of flour, the higher in it. sugar content. The total sugar content in wheat flour is 0.8-1.8%. Flour's own sugars are easily fermented by yeast in the first 1.5-2 hours of dough fermentation, this is their technological significance.
Starch is the most important carbohydrate, the content of which can reach 80% on CB flour. The more starch in flour, the less protein it contains. The technological significance of starch in the production of bread is very high: in the process of kneading dough, a significant part of the added water is retained on the surface of starch grains (especially mechanically damaged ones). In the process of fermentation, under the action of the enzyme β-amylase, part of the starch is saccharified. turning into maltose, necessary for the fermentation of the dough. When baking bread, starch gelatinizes, binding most of the moisture. In the gelatinized state, starch has colloidal properties and, together with gluten, determines the consistency of dough-bread, ensures the formation of the structure of bread and the formation of a dry elastic crumb. The gelatinization temperature of wheat starch is 62-65 °C.
Cellulose, hemicelluloses and lignin are dietary fibers that have a significant impact on the nutritional value and quality of bread. They are found mainly in bran, are not absorbed by the human body and mainly perform physiological functions, removing heavy metals from the body and reducing the energy value of bread.
The content of these carbohydrates also depends on the type of flour. In wholemeal flour, there is about 2.3% fiber, and in high-quality flour - 0.1-0.15%, the content of hemicelluloses is 2.0 and 8.0%, respectively. Cellulose and hemicellulose, due to the capillary-porous structure, absorb moisture well and increase the water absorption capacity of flour, especially wallpaper flour. Slimes, or gums, are colloidal polysaccharides that form viscous and sticky solutions when combined with water. In wheat flour they contain 0.8-2.0%, in rye - up to 2.8%.
Lipids - fats and fat-like substances play an important role in physiological and biochemical processes. Wheat and rye flour, depending on the variety, contains 0.8-2.5% fat. The composition of fat consists mainly of unsaturated high molecular weight fatty acids. Lipids contain a large group of fat-soluble vitamins (A, D, E, K). When storing flour, fat easily decomposes, which can cause spoilage of flour (rancidity).
Fat-like substances include phosphatides (0.4-0.7%) and other compounds. Phosphatides, unlike fats, in addition to glycerol and fatty acids contain phosphoric acid and a nitrogenous base.
Wheat flour enzymes act as regulators of biochemical processes. These are biological catalysts of a protein nature, which have the ability to accelerate the course of various biochemical reactions in semi-finished bakery products. From a large number enzymes contained in wheat flour, proteolytic enzymes acting on protein substances are very important, then amylases (α- and β-amylases hydrolyzing starch, α-glucosidase hydrolyzing maltose, and β-glycerol-lipase catalyzing the breakdown of lipids) .
Vitamins are part of the active part of enzymes. Flour contains many important vitamins: thiamine (B1), riboflavin (B2), pantothenic acid (B3), pyridoxine (B6), tocopherol (E), niacin (PP), etc.
Pigments are the coloring matter of flour. The most important are carotenoids, which color the flour particles yellow and orange.
Moisture in flour is of great importance in assessing its quality, storage stability and technological merit. Moisture, which is part of the composition of flour, is an active participant in all biochemical and microbiological processes. Of great importance is the critical moisture content of flour - 15.0%. Below this level, all processes in the flour proceed slowly, and the quality of the flour remains unchanged. At high humidity, the respiration of microorganisms and the flow of biochemical processes are significantly enhanced, which leads to the loss of dry matter (DM), self-heating and a rapid deterioration in the quality of flour.
There is a close relationship between flour moisture and enzyme activity. Water is an obligatory participant in enzymatic processes. With an increase in the moisture content of flour, the activity of enzymes increases. The form and types of connection of moisture with dry substances of flour affect the processes occurring in it, its safety, processing modes and nutritional value. Distinguish between free and bound moisture.
Under free understand moisture, which has a low binding energy with grain tissues and is easily removed from it. The presence of free moisture causes a significant intensity of respiration and biochemical processes that make flour unstable during storage and lead to its rapid deterioration and deterioration of baking properties.
Under related understand moisture with high binding energy with flour components. It determines the stability of the flour during storage.
Bound moisture has a number of features. Compared to drop-liquid moisture, it has more low temperature freezing (down to -20 ° C and below), lower specific heat capacity, reduced vapor pressure; high heat of vaporization, low ability to dissolve solids.
Humidity, below which the biochemical processes in flour are sharply weakened, and above which they begin to intensively accelerate, is called critical. At the same time, free moisture appears in the flour, i.e., water with a reduced binding energy, which ensures the intensification of enzymatic processes. For wheat, rye and triticale flour, the critical moisture content is 15%.
Hygroscopic moisture- this is moisture sorbed by flour from the air: equilibrium is moisture, the content of which corresponds to a given combination of relative humidity and air temperature. The moisture content of flour, corresponding to the state of equilibrium, is called equilibrium. The value of equilibrium humidity is influenced by temperature: at the same relative humidity, a higher temperature corresponds to a lower equilibrium moisture content of flour, and vice versa, when the temperature decreases, the equilibrium moisture content of flour increases.
Most of the substances that make up flour are capable of limited swelling in water. These include most proteins, starch, fiber, mucus and other high molecular weight carbohydrates. He swells in water and does not. hydrophobic substances dissolve in it - lipids, fat-soluble pigments and vitamins, carotenoids, chlorophyll, etc. Some flour substances (sugars, free amino acids, albumins, phosphates, most levulezanes, etc.) dissolve in water. Protein substances, swelling, absorb up to 250% of water, starch - up to 35%, mucus - up to 800%.
Substances capable of swelling in water make up 80% in wheat flour of the highest grade, 72% in rye flour.

The chemical composition of flour determines its nutritional value and baking properties. The chemical composition of flour depends on the composition of the grain from which it is obtained, and the type of flour. Higher grades of flour are obtained from the central layers of the endosperm, so they contain more starch and less proteins, sugars, fat, minerals, vitamins, which are concentrated in its peripheral parts. The average chemical composition of wheat and rye flour is presented in table 10.

Table 10 Chemical composition of flour, in % of dry matter

Type and grade of flour	Starch	Squirrels	Pentosans	Fats	Sahara	Cellulose	Ash
Wheat flour: top grade first grade second grade wallpaper	79,0	12,0	2,0	0,8	1,8	0,1	0,55
	77,5	14,0	2,5	1,5	2,0	0,3	0,75
	71,0	14,5	3,5	1,9	2,8	0,8	1,25
	66,0	16,0	7,2	2,1	4,0	2,3	1,90
Rye flour: seeded wholemeal	73,5	9,0	4,5	1,1	4,7	0,4	0,75
	67,0	10,5	6,0	1,7	5,5	1,3	1,45
	62,0	13,5	8,5	1,9	6,5	2,2	1,90

Most of all, both wheat and rye flour contain carbohydrates (starch, mono- and disaccharides, pentosans, cellulose) and proteins, the properties of which determine the properties of the dough and the quality of bread.

Carbohydrates. Flour contains a variety of carbohydrates: simple sugars, or monosaccharides (glucose, fructose, arabinose, galactose); disaccharides (sucrose, maltose, raffinose); starch, cellulose, hemicelluloses, pentosans.

Starch- the most important carbohydrate of flour, is contained in the form of grains ranging in size from 0.002 to 0.15 mm. The size and shape of starch grains are different for different types and grades of flour. The starch grain consists of amylose, which forms the inner part of the starch grain, and amylopectin, which makes up its outer part. The quantitative ratios of amylose and amylopectin in the starch of various cereals are 1:3 or 1:3.5. Amylose differs from amylopectin in its lower molecular weight and simpler molecular structure. The amylose molecule consists of 300-8000 glucose residues forming straight chains. The amylopectin molecule has a branched structure and contains up to 6000 glucose residues. AT hot water amylopectin swells and amylose dissolves.

In the process of making bread, starch performs the following functions:

is a source of fermentable carbohydrates in the dough, undergoing hydrolysis under the action of amylolytic enzymes (a- and p-amylases);
absorbs water during kneading, participating in the formation of the dough;
gelatinizes during baking, absorbing water and participating in the formation of bread crumb;
responsible for the staleness of bread during storage.

The process of swelling of starch grains in hot water is called gelatinization. At the same time, starch grains increase in volume, become looser and easily amenable to the action of amylolytic enzymes. Wheat starch gelatinizes at a temperature of 62-65 ° C, rye - 50-55 ° C.

The starch condition of the flour affects the properties of the dough and the quality of the bread. The size and integrity of starch grains affect the consistency of the dough, its water absorption capacity and the content of sugars in it. Small and damaged grains of starch are able to bind more moisture in the dough, they are easily amenable to the action of enzymes during dough preparation than large and dense grains.

The structure of starch grains is crystalline, finely porous. Starch has a high ability to bind water. When baking bread, starch binds up to 80% of the moisture in the dough. When storing bread, starch paste undergoes “aging” (syneresis), which is the main cause of stale bread.

Cellulose, hemicelluloses, pentosans belong to the dietary fiber group. Dietary fibers are found mainly in the peripheral parts of the grain and therefore they are most abundant in high-yield flour. Dietary fiber is not absorbed by the human body, so they reduce the energy value of flour, while increasing the nutritional value of flour and bread, as they accelerate intestinal motility, normalize lipid and carbohydrate metabolism in the body, and contribute to the removal of heavy metals.

Pentosans flour can be soluble or insoluble in water.

Part of the flour pentosans can easily swell and dissolve in water (peptize), forming a very viscous mucus-like solution.

Therefore, water-soluble flour pentosans are often referred to as slimes. It is mucus that has the greatest influence on the rheological properties of wheat and rye dough. Of the total amount of pentosans in wheat flour, only 20-24% are water-soluble. There are more water-soluble pentosans in rye flour (about 40%). Pentosans, which are insoluble in water, swell intensively in the dough, binding a significant amount of water.

Fats are esters of glycerol and higher fatty acids. The composition of flour fats includes mainly liquid unsaturated acids (oleic, linoleic and linolenic). Fat content in different varieties wheat and rye flour 0.8-2.0% on dry matter. The lower the grade of flour, the higher the fat content in it.

Fat-like substances include phospholipids, pigments, and some vitamins. These substances are called fat-like because, like fats, they do not dissolve in water, but are soluble in organic solvents.

Phospholipids have a structure similar to fats, but, in addition to glycerol and fatty acids, they also contain phosphoric acid and nitrogenous substances. Flour contains 0.4-0.7% phospholipids. Flour dyes (pigments) consist of chlorophyll and carotenoids. The chlorophyll contained in the shells is a green substance, the carotenoids are yellow and orange. When oxidized, carotenoid pigments become colorless. This property is manifested during storage of flour, which brightens as a result of oxidation of carotenoid pigments by air oxygen.

Flour is a product that is obtained in the process of grinding various grains (wheat, rye) or legume seeds (peas, soybeans). It occupies an important place in human nutrition. Flour is widely used for confectionery, pasta and other areas of the food industry. What is the agony?

Types of wheat flour

It is made from the most ancient cereal known in the world. It is impossible to imagine the cuisine of the peoples of the planet without wheat flour. There are different varieties of wheat. The most famous include: soft, hard and dwarf. Varieties of wheat flour:

top grade;
1st grade;
2nd grade.

In the highest grade, fiber and particles of the shell of each grain are completely absent. It turns out soft and airy, but, according to nutritionists, completely useless. Flour products inhibit digestion and do not stimulate intestinal motility. They give the body a lot of calories, but provide a minimum amount of vitamins. Products that are made from premium flour do not bring any benefit to the body.

What is the nutritional value wheat flour 100 g contains 334 kcal. The product contains proteins (10.3 g), fats (1.10 g) and carbohydrates (68.9 g).

The first grade of flour differs only in the size of the grains. She has a yellow color. Baking from it stales more slowly than from the highest grade, it is elastic and has a wonderful aroma. It is often mixed with the second grade to obtain products that contain a rich vitamin composition.

What is the nutritional value food flour? 100 g of the product contains: proteins (11.1 g), fats (1.5 g) and carbohydrates (67.8 g). The calorie content is 329 kcal.

The second grade of flour has special advantages, and it is used for baking bread and confectionery products. Its color is light gray, and sometimes brown. It will not work to bake a biscuit from such flour, and pancakes, waffles, dumplings turn out just fine. Although the products cannot boast of whiteness and splendor, their composition contains proteins, vitamins and minerals in large quantities.

For a long time, such products do not get stale, have a special aroma and excellent taste. Supporters proper nutrition and people who watch their weight have abandoned pastries of the highest grade in favor of products made from second-grade flour.

What is the chemical composition and nutritional value of flour? The product contains: proteins (11.7 g), carbohydrates (63.7 g) and fats (1.81 g). The calorie content of flour of the 2nd grade is 324 kcal.

Types of flour differ in the degree of processing of the grains themselves. Exist:

Krupchatka, no different from the varietal, in which all shells are also removed. Particle sizes up to 0.5 mm.
Wholemeal flour is made from unrefined wheat grains with bran. It contains many vitamins, minerals and fiber. The coarsest parts are removed during processing.
Whole grain flour is made from unprocessed. It has huge health benefits, but is useless for making flour products.
Peeled flour is made from the outer hulls of wheat.

It contains few carbohydrates, and contains vitamins and fiber in large quantities.

The peculiarity of the production of wheat flour lies in its various characteristics, which determine the dietary and gastronomic properties of the product.

properties of wheat flour

The product is rich in carbohydrates, as well as fats and proteins.

What is the nutritional value and chemical composition of flour? It is rich in dietary fiber, and is, in comparison with other types of product, starchy.

Wheat flour contains:

Magnesium, potassium. They support the myocardium, the work of the heart and blood vessels.
Phosphorus. The element improves the condition of the brain.
Calcium and sulfur contribute to the production of estrogen, prevent the development of osteoporosis and ligament diseases.
Copper. Allows the body to withstand severe psychological stress.
Zinc. Provides skin regeneration.
Molybdenum. Participates in the regeneration of liver and kidney tissues.

Together with vitamins, minerals activate tissue respiration and protein metabolism, calm the nerves, and prevent the development of gallstone disease.

What is the energy value of food flour? Coarse varieties contain fiber, therefore, they contribute to the establishment of intestinal motility and prevent the occurrence of decay processes in the digestive tract.

Due to the chemical composition and nutritional value of wheat flour, this ingredient is widely used in baking. Its benefits are palpable in high energy value. Nutritionists do not recommend including flour in the diet of people who are prone to obesity. Its carbohydrates are capable of releasing an incredible amount of energy that can only be spent when playing sports. In the absence of activity, extra calories are stored. There is a deterioration in metabolic processes, an increase in the amount of sugar in the blood. As a result, there are prerequisites for the development of diabetes and hypertension.

What is the nutritional value of premium flour? It has enough calories. The main characteristics of flour include the excess of gluten, which causes allergic reactions in the body.

The benefits and harms of wheat flour

An important indicator characterizing the grade of flour is the content of gluten in it. This criterion is determined by the amount of vegetable proteins that contribute to the adhesion of particles during kneading. For the human body, a large amount of gluten harms the digestive system.

What is the nutritional value of premium flour? It has a different calorie content depending on the variety. For obese people and diabetics, many flour products are contraindicated.

Bread made from peeled or whole grain flour has positive properties and can be included in the diet. He is the source of strength. Bread can provide a person with all the necessary energy resources. Therefore, the use of wheat flour is necessary as one of the ways to obtain the calories necessary for life, and it also makes it possible to prepare excellent pastries.

Rye flour

What is the nutritional value of rye flour? The product is the source useful substances and vitamins, it was the basis of nutrition in Russia. Proteins and carbohydrates help provide the body with energy.

Nutritional value of flour per 100 g: proteins (8.9 g), carbohydrates (61.8) g and fats (1.7 g). It also contains minerals and vitamins:

calcium takes part in the activity of the nervous system and contributes to the construction of the skeleton;
potassium helps transmit nerve impulses;
iron and magnesium have a positive effect on the heart and blood vessels;
phosphorus ensures the normal formation of bones and cartilage;
vitamin B1 supports the nervous system and metabolism in the body;
vitamin B2 improves the functioning of the thyroid gland and has a positive effect on reproductive function.

In places where there is no sun and heat, rye bread is necessary for the normal functioning of the body. It is needed by people who suffer from anemia or metabolic disorders. In spite of positive traits, rye bread is not recommended for people with stomach ulcers and high acidity.

What is the nutritional value of rye flour? Its calorie content in 100 g is 298 kcal.

Varieties of rye flour include pecked, seeded, wholemeal and peeled rye flour. They have differences in the degree of grinding and the content of bran particles.

Pecked flour refers to the finest grinding. It is used for the production of gingerbread, pies, etc. Products made from seed flour have a low calorie content. It contains a minimum amount of dietary fiber. Peeled rye flour nutritional value: proteins (8.9 g), fats (1.7 g) and carbohydrates (60.2 g). It is used for baking bread. Peeled flour must be mixed with wheat flour. Such bread is especially fragrant and healthy.

Wholemeal flour has the coarsest grinding. It has an increased percentage of bran particles. When wheat flour is added, wholemeal is used to produce some types of bread. By the amount of fiber, it overtakes some types of product. Wholemeal flour has 3 times more nutrients than wheat flour. It is included in the diet for constipation, high cholesterol and atherosclerosis.

Oat flour

Known as a dietary product since antiquity. Produced from mature oatmeal. Flour contains many nutrients. The composition contains essential amino acids (tyrosine, choline), a lot of calcium and mineral salts, as well as a rare element - silicon.

Oatmeal is rich in the following trace elements and vitamins: iron, magnesium, manganese, zinc, vitamins PP, E and A, B vitamins (thiamine, riboflavin, pyridoxine, folic acid).

There are such varieties of oatmeal:

Oatmeal. After a special treatment, sprouted oat grains are crushed.
Traditional finely ground oatmeal.

The positive properties of flour include the following:

regulation of fat metabolism.
Contains a protein involved in the regeneration of many types of tissue.
Easily digestible and normalizes the digestive system.
Promotes stable liver function.
Improves the activity of the nervous system.
Produces serotonin, which affects a person's mood.

What is the agony? It is classified as a high-calorie foods that can lead to overweight. The nutritional value of 100 g of oatmeal is: proteins (13 g), fats (6.8 g) and carbohydrates (64.9 g). Its calorie content is 369 kcal. Oatmeal is used for baking. The most famous product from it is oatmeal cookies.

Corn flour

The product has long been eaten by Indian peoples. Flour is made from sweet corn kernels. It is gluten-free and can be consumed by people who cannot tolerate gluten.

Corn flour is:

coarse grinding used in dietetics;
medium grinding, from which bread is baked;
fine grinding - used for tender dough and puddings.

Corn Product Colors:

Blue flour has a sweet taste and a bluish or purple hue.
Red flour has a special taste. Used in Spain to make polenta.
Yellow flour is the most widespread in the world.
White flour is made from a variety of corn that grows in Africa and the southern United States.

What is the nutritional value of cornmeal? The product contains a large amount of carbohydrates (up to 76% of its composition). Fiber allows you to feel increased saturation with cornmeal products. It is poor in amino acids and tryptophan. It contains a large number of micro and macro elements. There are many vitamins in flour: riboflavin, thiamine, niacin, etc.

The positive properties of cornmeal include the following:

normalizes the work of the stomach and intestines;
has good choleretic properties;
contributes to the prevention of hypertension;
used as a component of anti-aging face masks.

People who suffer from increased blood clotting should not eat cornmeal, so as not to aggravate the problem.

Rice flour

In most cases, cereals are used for eating and making flour. The nutritional value of rice flour is: proteins (6 g), fats (1.42 g) and carbohydrates (80 g).

It is produced from grains by grinding. There are two types of rice flour: white rice flour and whole wheat flour.

The first type of product has a white color and a light texture. It contains a lot of starch and no gluten.

Whole grain flour is made from grains that have been stripped of their outer shells. She possesses dark color and nutty flavor.

It does not include gluten, so it is used for the production of baby food and is used in the diet menu. Rice flour is rich in the following components:

vitamins B, E and PP;
minerals (potassium, calcium, phosphorus, iron, zinc, selenium);
fatty acids;
fiber.

The benefits of rice flour are as follows:

Improves the work of the heart muscle.
Restores strength and energizes.
Normalizes the work of the digestive tract.
Refers to natural antidepressants.
Protects from stressful situations and the harmful effects of the environment.
Reduces blood glucose levels.
Accelerates metabolic processes in the body.

Rice flour should not be consumed by people who suffer from constipation. Big nutritional value causes weight gain, so people who are overweight are not recommended to eat it.

Flax flour

Grain culture has long been used by our ancestors. Flaxseed flour is obtained by grinding seeds with their further degreasing. It is not as widespread as wheat and rye, but is used in a healthy diet.

The nutritional value of flaxseed meal is: proteins (36 g), fats (10 g) and carbohydrates (9 g). Its calorie content is 270 kcal.

The composition of flaxseed flour includes:

vitamin B1, B6, B2 and folic acid;
minerals (potassium, zinc, magnesium);
fatty acids Omega-3 and Omega-6;
vegetable proteins.

Substances help cleanse the body of harmful substances and toxins.

Flaxseed flour is used as a prophylactic:

With diseases of the heart and blood vessels.
With pathology of the respiratory system (cough, shortness of breath).
With a disease of the genitourinary system.

Doctors believe that flour dishes should be included in the diet for the health of the female body. Flax flour has a positive effect on the fetus during pregnancy. Excellent effect on the condition of hair and skin.

soy flour

The product is especially popular with adherents of a vegetarian diet. obtained by grinding soybean seeds, oilcake and sprat. It is produced on an industrial scale.

The nutritional value of soy flour is: proteins (48.9 g), fats (1 g) and carbohydrates (21.7 g).

There are the following varieties:

full-fat, which is obtained from soybeans;
semi-skimmed, produced from beans, cake and sprat;
fat-free is obtained from cake or sprat.

The composition of soy flour includes:

Vitamins B, E, PP, beta-carotene, provitamin A.
Minerals (calcium, phosphorus, magnesium, potassium, iron).
Alimentary fiber.

The positive properties of soy flour include:

cleansing the blood of bad cholesterol;
improving fat metabolism and reducing excess weight;
cleansing of toxins and harmful substances.

Soy flour is consumed by people who are allergic to animal protein. It is able to completely replace protein for vegetarians, because they completely refuse to eat meat, fish and dairy products.

Despite the positive properties, soy flour can cause the following harm:

Negatively affects the human endocrine system.
Causes rapid aging of the body.
Violates cerebral circulation.
Increases the chance of miscarriage both early and late later dates pregnancy.
Leads to male and female infertility.

When deciding whether to eat soy flour, you should consider its positive and negative properties.

How to properly store flour

The product is necessary for the preparation of various dishes. Flour has some secrets for storing it at home.

The product is well preserved in dry rooms at temperatures from 5 to 20 degrees. Thus, the flour can retain its properties for 12-18 months.

It is forbidden to store the product with spices and spices, as well as coffee and tea. Flour has the ability to easily absorb foreign unpleasant odors becomes unsuitable for further cooking.

When buying a product in a paper bag for further storage, it must be placed in another container. It is convenient to spread the flour in glass or metal containers with lids. Some housewives keep it in canvas bags.

If the flour was bought several months ago, in order to avoid souring or mold, it must be dried by scattering it in a thin layer on a sheet of paper.

It is important to protect the product from the appearance of various insects in it, such as bugs, mealworms and others. They can eat half the flour and spoil the rest with waste products. In this case, the product must be sifted and folded into canvas bags.

Sometimes garlic is used to prevent the appearance of insects in the flour. The phytoncides contained in it repel them without harming the product.

Flour is a product that no housewife can do without. From it you can cook a lot of products that are suitable for both everyday and festive tables. Flour different varieties and species has its positive and negative properties, so it is up to the individual to decide which product to use.