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Calorie Whole wheat flour. Chemical composition and nutritional value. Wheat flour Malt wheat flour nutritional value

07.12.2020

Introduction

flour classification

The nutritional value

1.1 Chemical composition of flour

1.2 Nutritional and energy value

Factors that shape the quality of flour

1.3 Raw material

1.4Technology of flour production

1.5Technological defects and defects

Factors Preserving Flour Quality

1.6Packaging and labeling of flour

1.7Storage and transport

1.8 Implementation

1.9Falsification of flour

Flour quality assessment

1.10Organoleptic indicators

1.11 Physical and chemical parameters

1.12Safety performance

Conclusion

Bibliography

Appendix

Introduction

In this term paper on the topic: "Commodity characteristics of flour" we will consider such key issues as:

- Nutritional value, chemical composition of wheat and rye flour

- Classification and range

- Quality, defects of wheat and rye flour

- Packaging, labeling, storage of wheat and rye flour.

Relevance of the topic term paper due to the fact that today a lot of attention is paid by consumers to the quality of products. The successful promotion of the product on the consumer market and its ability to compete with similar products depend on the quality. Flour is a powdered product obtained by grinding cereal grains.

The flour milling industry is the largest branch of the food industry, which produces flour for retail trade, as well as for baking, confectionery and other industries. Flour is the main product of grain processing, it is of paramount importance in supplying the population with essential products, as it is used to make baked bread.

The group of grain products occupies almost 20% of the consumer basket of a Russian. Groats, bakery products, pasta are essential goods, so the flour and cereals market can be called socially significant.

Wheat flour- flour obtained from wheat grains.

Wheat flour is perhaps the most popular baking flour in the world. It comes in several types.

High-grade flour (some packages say the word “extra”) has quite a bit of gluten, and it looks completely white. Such flour is ideal for pastries, it is often used as a thickener in sauces.

Flour of the first grade is good for lean pastries, and its products become stale much more slowly. In France, it is customary to bake bread from wheat flour of the first grade.

As for second grade flour, it contains up to 8% bran, so it is much darker than first grade. It is used in our country - it is from it that they make lean products and ordinary white bread, and mixed with rye flour - black.

Rye is one of the most important cereal crops. The consumption rate of rye flour (as a percentage of all cereals) is about 30.

Rye flour has numerous beneficial properties. It contains the amino acid necessary for our body - lysine, fiber, manganese, zinc. Rye flour contains 30% more iron than wheat flour, as well as 1.5-2 times more magnesium and potassium. Rye bread is baked without yeast and on thick sourdough.

Therefore, the use of rye bread helps to reduce cholesterol in the blood, improves metabolism, heart function, removes toxins, helps prevent dozens of diseases, including cancer.

Due to the high acidity (7-12 degrees), which protects against the occurrence of mold and destructive processes, rye bread is not recommended for people with high acidity of the intestines, suffering from peptic ulcers. The 100% rye bread is really too heavy for daily consumption. The best option: rye 80-85% and wheat 15-25%. Varieties of rye bread: from white flour, from peeled flour, rich, simple, custard, Moscow, etc.

The purpose of this course work is to consider the main characteristics of wheat and rye flour, as well as to identify the requirements for the quality of flour sold on the territory of the Russian Federation and the GOSTs regulating it.

To achieve this goal, it is necessary to perform a number of tasks:

- to study the nutritional value, chemical composition of wheat and rye flour

- to consider the classification and assortment

- disclose such indicators as: quality, defects of wheat and rye flour

- consider the rules for packaging, labeling and storage of wheat and rye flour

- Analyze the range of new products.

flour classification

In accordance with GOST R 52189-2003 Flour wheat . General specifications. Wheat flour, depending on its intended use, is divided into:

wheat bakery;

general purpose wheat.

Wheat bread flour depending on the whiteness or mass fraction of ash, mass fraction of crude gluten, as well as the fineness of grinding, they are divided into varieties: extra, higher, grit, first, second and wallpaper.

All-purpose wheat flour depending on the whiteness or mass fraction of ash, the mass fraction of raw gluten, as well as the fineness of grinding, they are divided into types: M45-23; M 55-23; MK 55-23; M 75-23; MK 75-23; M 100-25; M 125-20; M 145-23.

Wheat flour can be enriched with vitamins and/or minerals in accordance with the standards approved by the Russian Ministry of Health, as well as baking improvers, including dry gluten, in accordance with the approved regulatory document.

To the name of such flour, respectively, add: "fortified", "enriched with minerals", "enriched with a vitamin-mineral mixture", "enriched with dry gluten" and other baking improvers.

In flour enriched with vitamins, a slight odor characteristic of vitamin B1 (thiamine) is allowed.

Baking wheat flour is produced for retail, confectionery and baking industries. By quality, it is divided into grains, flour of the highest, 1st and 2nd grade, as well as wallpaper. Varieties of flour differ in color, grinding size, chemical composition, gluten content, baking properties and other indicators.

Krupchatka obtained from glassy soft and hard wheats. Flour in the form of homogeneous grains of yellow-cream color; flour yield - 10%; its ash content is 0.6%; crude gluten content – 30%. Used for baking sweets and pasta.

Flour of the highest grade are made from soft glassy and semi-glassy wheats. The flour is soft to the touch, the color is white or white with a creamy tint; flour yield - 10-15; 40%; ash content - 0.55%; raw gluten content 28%. Used for sale to the population, production of confectionery and bakery products.

Flour of the 1st grade obtained from soft and vitreous wheats. It is soft, white in color with a slight yellowish tint; yield - from 30 to 72% (depending on the method of grinding); ash content - 0.75%; crude gluten content - 30%. This flour is widely used in the baking, confectionery industry, as well as for sale to the population.

2nd grade flour made from soft wheat. Its particles are heterogeneous in size; color white with a yellowish-grayish tint; flour yield - up to 85%; ash content - 1.25%; gluten content not less than 25%. It is used to make bread.

wallpaper flour obtained from soft wheats with single-grade wholemeal grinding without screening out bran, so the flour yield is high - 96%; flour particles are heterogeneous in size; grayish white color; ash content - up to 2%; gluten content - 20%. Flour is used to make bread.

Wheat flour for pasta. It is obtained by special three-grade grinding of durum wheat with a high gluten content. good quality. The particles of this flour are larger than bread flour. According to the quality, pasta flour is divided into the highest (grains) and the 1st (semi-grains) grades. Cream-colored premium flour; ash content of flour - 0.7%; raw gluten - 28-30%. Flour of the 1st grade is softer; ash content of flour - 1.1%, gluten - 30-32%.

In accordance with GOST R 52809-2007 baking rye flour, depending on the quality, is divided into varieties:

peeling;

Seeded flour- the highest quality grade of rye flour. It consists of finely ground rye grain endosperm with a small admixture of particles of the aleurone layer and shells (only about 4% of the flour mass). Particle size from 20 to 200 microns. The color of the flour is white with a bluish tint. Flour is rich in starch (71-73%), sugars (4.7-5.0%), contains a significant amount of water-soluble substances and relatively little protein (8-10%) and fiber (0.3-0.4%). The ash content of flour is 0.65-0.75%.

Peeled flour differs from the wallpaper in a lower content of shells and an aleurone layer of grain (12-15% of the mass of flour), as well as a higher degree of grinding. Particle size from 30 to 400 microns. The color of the flour is white with a gray or brownish tint. Peeled flour, like wholemeal flour, is rich in water-soluble substances, but contains less protein (10-12%), more starch (66-68%). The fiber content in this flour is 0.9-1.1%, and the ash content of the flour is 1.2-1.4%.

Whole flour is a grain of rye, ground after cleaning it from impurities and processing on scouring machines. Flour is obtained with single-grade 95% grinding by passing through wire sieves 067.

Wholemeal flour consists of the same tissues as rye grain (with a slightly smaller amount of fruit shells and germ) and contains, along with crushed endosperm, 20-25% of crushed shells and the aleurone layer. Particle size from 30 to 600 microns. The color of the flour is white with a pronounced gray, yellowish or greenish tint, depending on the color of the rye grain. Flour is rich in water-soluble substances, sugar contains 12-14% protein, 60-64% starch, fiber - 2-2.5%, ash content - 1.8-1.9%.

The nutritional value

The chemical composition of flour.

Consider the features of the quantitative and qualitative composition of flour determine its nutritional value and baking properties.

Nitrogen and proteins

The nitrogenous substances of flour are mainly composed of proteins. Non-protein nitrogenous substances (amino acids, amides, etc.) are contained in not in large numbers(2-3% of the total mass of nitrogenous compounds). The higher the yield of flour, the more nitrogenous substances and non-protein nitrogen are contained in it.

Wheat flour proteins. Simple proteins predominate in flour. Flour proteins have the following fractional composition (in%): prolamins 35.6; glutelins 28.2; globulins 12.6; albumins 5.2. The average content of proteins in wheat flour is 13-16%, insoluble protein is 8.7%.

The composition of gluten. Raw gluten contains 30-35% solids and 65-70% moisture. Gluten solids are 80-85% composed of proteins and various flour substances (lipids, carbohydrates, etc.), with which gliadin and glutenin react. Gluten proteins bind about half of the total amount of flour lipids. Gluten protein contains 19 amino acids. Glutamic acid predominates (about 39%), proline (14%) and leucine (8%). Gluten of different quality has the same amino acid composition, but different molecular structure. The rheological properties of gluten (elasticity, elasticity, extensibility) largely determine the baking value of wheat flour.

Rye flour proteins. According to the amino acid composition and properties, rye flour proteins differ from wheat flour proteins. Rye flour contains a lot of water-soluble proteins (about 36% of total weight protein substances) and salt-soluble (about 20%). The prolamin and glutelin fractions of rye flour are much lower in weight; they do not form gluten under normal conditions. The total protein content in rye flour is somewhat lower than in wheat flour (10-14%). Under special conditions, a protein mass can be isolated from rye flour, resembling gluten in elasticity and extensibility.

Carbohydrates

The carbohydrate complex of flour is dominated by higher polysaccharides (starch, fiber, hemicellulose, pentosans). A small amount of flour contains sugar-like polysaccharides (di- and trisaccharides) and simple sugars (glucose, fructose).

Starch. Starch, the most important carbohydrate in flour, is contained in the form of grains ranging in size from 0.002 to 0.15 mm. The size, shape, swelling capacity and gelatinization of starch grains are different for flour. various kinds. The size and integrity of starch grains affects the consistency of the dough, its moisture capacity and sugar content. Small and damaged grains of starch are saccharified faster in the process of making bread than large and dense grains.

Cellulose. Cellulose (cellulose) is located in the peripheral parts of the grain and therefore is found in large quantities in flour of high yields. Wholemeal flour contains about 2.3% fiber, and wheat flour of the highest grade contains 0.1-0.15%. Fiber is not absorbed by the human body and reduces the nutritional value of flour. In some cases, a high fiber content is useful, as it accelerates the peristalsis of the intestinal tract.

Hemicelluloses. These are polysaccharides belonging to pentosans and hexosans. In terms of physicochemical properties, they occupy an intermediate position between starch and fiber. However, hemicelluloses are not absorbed by the human body. Wheat flour, depending on the variety, has a different content of pentosans - the main component of hemicellulose.

Flour of the highest grade contains 2.6% of the total amount of grain pentosans, and flour of the II grade contains 25.5%. Pentosans are divided into soluble and insoluble. Insoluble pentosans swell well in water, absorbing water in an amount exceeding their mass by 10 times.

Soluble pentosans or carbohydrate mucus give very viscous solutions, which, under the influence of oxidizing agents, turn into dense gels. Wheat flour contains 1.8-2% of mucus, rye flour - almost twice as much.

Lipids. Lipids are called fats and fat-like substances (lipoids). All lipids are insoluble in water and soluble in organic solvents.

Fats. Fats are esters of glycerol and high molecular weight fatty acids. In wheat and rye flour different varieties contains 1-2% fat. The fat found in flour has a liquid consistency. It consists mainly of glycerides of unsaturated fatty acids: oleic, linoleic (mainly) and linolenic. These acids have a high nutritional value, they are credited with vitamin properties. Hydrolysis of fat during storage of flour and further conversion of free fatty acids significantly affect the acidity, taste of flour and the properties of gluten.

Lipoids. Flour lipoids include phosphatides - esters of glycerol and fatty acids containing phosphoric acid combined with some nitrogenous base.

The flour contains 0.4-0.7% of phosphatides belonging to the group of lecithins, in which choline is the nitrogenous base. Lecithins and other phosphatides are characterized by high nutritional value and are of great biological importance. They easily form compounds with proteins (lipo-protein complexes), which play an important role in the life of every cell. Lecithins are hydrophilic colloids that swell well in water.

Pigments. Fat-soluble pigments include carotenoids and chlorophyll. The color of carotenoid pigments in flour is yellow or orange, and chlorophyll is green. Carotenoids have provitamin properties, as they are able to turn into vitamin A in the animal body.

Minerals

Flour consists mainly of organic matter and a small amount mineral (ash). The mineral substances of the grain are concentrated mainly in the aleurone layer, shells and embryo. Especially a lot of minerals in the aleurone layer. The content of minerals in the endosperm is low (0.3-0.5%) and increases from the center to the periphery, so the ash content is an indicator of the flour grade.

Most of the minerals in flour consist of phosphorus compounds (50%), as well as potassium (30%), magnesium and calcium (15%).

In negligible amounts contains various trace elements (copper, manganese, zinc, etc.). The iron content in the ashes of different types of flour is 0.18-0.26%. A significant proportion of phosphorus (50-70%) is presented in the form of phytin - (Ca - Mg - salt of inositol phosphoric acid). The higher the grade of flour, the less minerals it contains.

Enzymes

Cereal grains contain a variety of enzymes, concentrated mainly in the germ and peripheral parts of the grain. In view of this, high-yield flour contains more enzymes than low-yield flour.

Enzyme activity in different batches of flour of the same variety is different. It depends on the conditions of growth, storage, modes of drying and conditioning of the grain before grinding. Increased activity of enzymes was noted in flour obtained from unripe, sprouted, frost-bitten or bug-damaged grain. Drying grain under a hard regime reduces the activity of enzymes, while storing flour (or grain) it also decreases somewhat.

Enzymes are active only when the humidity of the environment is sufficient, therefore, when storing flour with a moisture content of 14.5% and below, the action of enzymes is very weak. After kneading, enzymatic reactions begin in semi-finished products, in which hydrolytic and redox flour enzymes participate. Hydrolytic enzymes (hydrolases) decompose complex flour substances into simpler water-soluble hydrolysis products.

Wholemeal flour has a lower digestibility and energy value, but a high biological value, it contains more vitamins and minerals.

Flour of the highest grades poorer useful substances, since they are concentrated mainly in the shells of the grain and the germ, which are removed when receiving flour, but are absorbed more easily and more fully.

flour 2nd grade obtained from soft wheat. The color is white with a yellowish-gray tint. Flour differs by the content of 8-10% shells, flour particles are larger than in the 1st grade, heterogeneous in size. Gluten content - not less than 25% ash content - not more than 1.25%. Flour of the 2nd grade is used in baking bread.

Whole flour is made from soft wheats with single-sorted wholemeal grinding without screening out bran. Flour yield - 96% Grayish-white color, gluten content - 20%, ash content, up to 2%. Used for baking bread.

Nutritional and energy value.

We consider the nutritional and energy value of flour in the form of a table

Table 1

				Carbohydrates
Buckwheat flour
Corn flour (dietary)
Wheat flour 1st grade
Wheat flour 2nd grade
Wheat flour
Whole wheat flour
Peeled rye flour
Rye flour
Rice flour (diet)
Wheat bran

Factors that shape the quality of flour.

Raw material.

The flour milling industry of our country produces five varieties

wheat flour and three grades of rye bread flour.

Grain - 10% Seeded - 63%

Premium - 30% Peeled - 87%

First grade - 72% Wallpaper - 95%

Second grade - 85%

Wallpaper - 96%

In addition, two varieties of wholemeal flour are prepared from a mixture of wheat and rye: wheat-rye and rye-wheat. The flour production process consists of preparing grain for grinding and grinding itself. Wholemeal flour is obtained by grinding the whole grain as a whole, other varieties (varietal flour) are prepared from endosperm with a small admixture of shells. Accordingly, grindings are divided into wallpaper (simple) and varietal (complex). Varietal grinding, depending on the amount of flour obtained from one batch, can be one-, two- and three-varietal.

The resulting amount of flour of each grade must correspond to the established rate of its output (the output is the amount of flour, expressed as a percentage of the mass of processed grain with a basic moisture content of 14.5%). Individual batches of grain have different quality indicators. To obtain flour of standard quality, batches of grain are sorted at the mill - they are made up of a grinding mixture. At the same time, moisture, ash content, color, vitreousness, gluten and other indicators of grain are taken into account. Preparation of grain for grinding consists in removing impurities, cleaning the surface of the grain and conditioning the grain mass. Weed and grain mixture is removed using special grain cleaning machines, metal impurities are removed on magnetic separators.

Flour production technology.

Flour mills are equipped with warehouses and elevators for grain, warehouses for storing finished products. The production process is completely mechanized. The principle of gravity is widely used in the technological process. Grain or intermediate products, lifted to the top floor by mechanical (noria) or pneumatic transport, enter the machines with the help of distributing devices and then go through gravity (gravity) pipelines to the machines located on the floor below.
To obtain flour of standard quality, the grain is cleaned and conditioned before grinding. Grain is prepared in two stages. The first stage is the cleaning of grain from weed impurities in separators, trieres, duaspirators; extraction of mineral impurities in stone-separating machines; washing of grain in washing machines and its conditioning in silos. The second stage is additional cleaning of grain in separators, duaspirators, brush machines, moisturizing in moisturizing machines and softening.
From the grain cleaning department, the grain enters the grinding department, where roller machines are located. The process in which the grain gradually unfolds and crumbles out of it, consisting of endosperm with fused shells, and the endosperm is partially crushed to a state of flour, is called tattered. This process involves four to six systems of rolling machines (I torn, II torn, etc.). The larger the system number, the finer the grooves at the rollers and the thinner the gap (the distance between the rollers). The products formed after each tearing system have different sizes and unequal endosperm content. The following products are obtained: flour, semolina (fine, medium and large), dunsta (medium between flour and small semolina). For separation by size, they are sent to screening machines (sieving). Next, grits and dunsts go to sieve machines, sorting them by quality. The sieving machines sort the products using tilted reciprocating sieve frames and air flow through the sieves and products. The most solid products, containing mainly endosperm, are sent to roller machines, where they are ground into flour. Grits and dunst are ground during successive grinding with sifting of finished flour in grinding roller machines. This process is called grinding. Grits with particles of the shell are sent to grinding roller machines equipped with rollers without corrugations, then again for sorting and screening in sieve machines. The process of processing grains containing shells is called grinding.
All the flour obtained from the working sifters goes to the control ones (to prevent the ingress of foreign objects, grain shells, etc.). After control screenings, the flour is transferred to a bulk storage warehouse or packed in bags. To increase the nutritional value, vitamins B1, B2, and PP are added to the flour of the highest and first grades. The technological process at the flour mill is accompanied by the release of dust. To capture it, an aspiration system is used. At a certain concentration in the air, grain and flour dust are explosive.

Technological defects and marriage.

The reason for the occurrence of defects in flour may be the use of low-quality grain, violation of manufacturing technology, non-compliance with modes and periods of storage. Self-heating of flour is an increase in temperature in its mass due to internal physiological processes and poor thermal conductivity. Among the physiological processes that occur in cereals and flour during self-heating, it is necessary to single out the process of respiration and the development of microorganisms. At the same time, the organoleptic indicators of flour (color, smell, taste) change. The foreign smell of flour occurs due to non-observance of the commodity proximity of their storage with products that tend to transmit smell (fish, spices, soap, cologne, etc.). The reason for the appearance of an extraneous taste in these products may also be extraneous aromatic impurities in the grain before its processing.

With prolonged storage, especially in the light, the flour becomes discolored, darkens. Wetting flour is the cause of other defects. Such products cannot be stored for a long time, they quickly deteriorate. The increased humidity of flour activates enzymes, increases the intensity of their respiration, self-heating, and the development of microorganisms. Moldy flour occurs due to self-heating or storage in poorly ventilated rooms with high relative humidity - above 80%. Products acquire a musty smell, acidity increases in them, their color becomes darker. Moldy flour clumps.

Flour souring begins in the inner layers of the product mass due to the development of acid-forming bacteria, primarily lactic acid bacteria. Souring occurs to a greater extent in flour and cereals. Rancidity in flour is the result of fat oxidation.

Flour with a high fat content will go bitter faster. Flour of the lower grades contains more particles of the germ rich in fats, so it will also go bitter faster. A decrease or loss in the flowability of cereals occurs with an increase in contamination in them, and in flour (in particular of lower grades) due to the large content of shell particles. This also happens at high humidity. The ability of flour to lose flowability partially or completely is called compaction or caking.

Caking is more characteristic of flour. With an increase in the duration of storage, the likelihood of flour caking increases. Flour that has lost its flowability due to the pressure of the upper layers of products on the lower ones is not used for long-term storage. If the flour is compacted and loses its flowability due to self-heating, the development of microorganisms and pests of grain stocks, it becomes unsuitable for consumption and is not allowed for sale. Flour with low baking properties is defective, for example, flour with a low gluten content and its low quality.

Factors Preserving Flour Quality

Packaging and labeling.

Flour packaging - according to GOST 26791-89 regulates the requirements for the packaging of wheat and rye flour. Packed in consumer packaging with a net weight in kilograms: 1,000; 2,000 and 3,000 for flour. Permissible deviations of the net weight of individual packaging units should not exceed in percentage: 1.0.

Flour is packaged in transport containers in new or used fabric grocery bags in accordance with GOST 30090 and other regulatory and technical documentation that ensure the safety of products.

Bags must be at least:

Category 2 - for flour from soft vitreous wheat for pasta; durum wheat flour (durum) for pasta; flour of the second grade from durum wheat (durum); wheat crushed grits;

Whole wheat flour for local supply is packed in bags of at least category 4. When transported by mixed railway - water transport or with reloading from one track to another, the flour is packed in new or used bags of at least category 1

In accordance with GOST R 51074-2003 the manufacturer (seller) is obliged to provide the consumer with the necessary and reliable information about food products, ensuring the possibility of their correct choice. This standard regulates grain processing products and must contain the following information:

Product name (for example, for flour: rye, rice, barley, corn, buckwheat, baking wheat, pancake wheat, etc.);

Grade or number (if any);

Name and location of the manufacturer [legal address, including the country, and, if not the same as the legal address, address(es) of production(s)] and the organization in the Russian Federation authorized by the manufacturer to accept claims from consumers on its territory (if any);

Trademark of the manufacturer (if any);

Net weight;

Composition of the product (except for one-component products);

Food additives, flavors, biologically active food supplements, ingredients of non-traditional products;

For fortified wheat baking flour the highest and first grades the word "VITAMINIZED" (in large print);

The nutritional value;

date of manufacture;

Storage conditions;

Shelf life;

Shelf life for corn flakes, wheat, rice and oatmeal;

Designation of the document in accordance with which the product is manufactured and can be identified;

Information about confirmation of conformity.

The same information is applied to the labels attached to the bags.

Storage and transportation.

Flour storage is regulated in accordance with GOST 26791.

The shelf life of flour is set by the manufacturer of products at an ambient temperature not higher than 25 ° C and relative air humidity not higher than 70%.

Flour is stored in dry, well-ventilated, pest-free grain stocks, warehouses in compliance with sanitary rules approved in the prescribed manner.

The shelf life of deodorized soybean flour at a relative humidity of 60% is 12 months from the date of production.

Flour can be stored in unheated and heated warehouses. Long-term storage of flour is carried out in unheated warehouses, and the temperature in them depends on the season.

Flour intended for retail trade usually comes in bags. Each batch of product received for storage is placed in a separate stack. The bottom row of bags is placed on solid wooden underlays to prevent sweating from contact with the cold floor. The distance from the walls to the stack must be at least 0.5 m, and the passages between them must provide free access to each stack.

During long-term storage, the stack is shifted at least twice a year, always changing places of the upper and lower bags.

As a rule, stores store relatively small batches of flour, which ensure an uninterrupted supply of the population for 10-45 days. The temperature is preferably not higher than 10-18 °C. In stores, it is necessary to strictly monitor the commodity neighborhood, since flour easily absorbs odors.

Flour is transported both in bags and in bulk.

When transporting small batches of flour in bags, you can use ordinary flatbed trucks, while covering the bags with a tarpaulin on top. For the mass transportation of flour in bags, specialized road trains are used, the bodies of which are equipped with a lifting overturning metal top, attached to the sides with latches. Before loading and unloading, the bolts are removed from the side from which you want to open the body. The latches of the opposite side serve as the axis of rotation of the top of the body. To prevent the top of the body from closing spontaneously, a safety comb with a latch and a special lock are provided. The use of such road trains makes it possible to transport flour in bags behind the seal of the sender, completely eliminates the ingress of moisture on the bags and the spraying of flour during transportation. Such road trains can also be used for the transportation of granulated sugar and cereals in bags.

For bulk bulk transportation of flour, road trains - flour trucks are used. Flour is unloaded from the tank pneumatically, for which a compressor is installed on the chassis of the car behind the cab, which provides pressure. Compressed air from the compressor through the air duct system enters the discharge pipe, the aeration box, the tank installed inside on the bottom closer to the discharge pipe. upper part tanks. The unloading capacity is 0.3-0.5 t/min. Thanks to the use of a pneumatic system, flour can be fed during unloading at a distance of up to 50 m and at a height of up to 25 m.

At the bakery, the road train is weighed and sent for unloading. The unloading branch pipe of the tank is connected to the receiving branch pipe of the transport pipeline of the factory silo, the compressor is turned on and compressed air first it is fed into the discharge pipe for blowing out the flexible pipeline, and then into the aeration box and the tank. Flour enters the discharge pipe, where it is picked up by a stream of air entering directly into the pipe and transported directly through the pipeline to the silo. The pressure gauge installed on the tank makes it possible to set the end of unloading. The use of flour trains provides a significant economic effect. The reduction in flour losses from spraying is about 3 kg for each transported ton. In addition, the use of flour trains significantly reduces the complexity of unloading and loading operations.

Implementation of flour.

The development trends of the flour-grinding sector of the European Union correspond to the world ones. Modern Russian mills meet all engineering requirements. Complex multifactorial technological process, the saturation of enterprises with technological and auxiliary equipment, automated control and management systems place increased demands on professional knowledge, organizational ability and the general cultural and intellectual level of process engineers. On the basis of modern technology, millers have reached a high level of realization of the technological potential of flour. The export of our flour to Europe is 60%. Further development is aimed at creating multifunctional circuits, reducing the process, reducing operating and energy costs. Market conditions dictate the expansion of the assortment, including special varieties: for dietary and baby food, for flour confectionery, etc.

Fake flour.

Flour is a relatively cheap product, so its assortment falsification is rare, mainly in market trade or small-scale wholesale delivery of flour by one-day firms.

At large flour mills, such cases are excluded, since along with in-house inspection control, which ensures the release of products of appropriate quality and assortment characteristics, the manufacturing organization risks losing the image of a reliable business partner and its market segment.

Assortment falsification of flour in modern conditions is carried out by mixing non-food substitutes, mainly sand or bran. The methods of assortment falsification known in pre-revolutionary Russia using chalk, lime, ash, and other types of flour are practically not used, since many of these falsifications are either inaccessible (for example, ash), or differ little from wheat flour in price (for example, prices wheat, rye, corn, barley flour, gypsum and chalk are about the same), or are easily detected when rubbed between fingers (lime). In addition, when adding chalk, gypsum, lime, a fake is easy to detect by adding acid to the aqueous suspension of flour. In the presence of these alkaline substitutes, they interact with acid and rapidly release carbon dioxide (C0 2). Qualimetric falsification is carried out by partial or complete replacement of the lowest grade flour with the highest, as well as the addition of bran. To give the necessary white color, the flour is bleached.

The method of high-quality falsification of flour described by I.P. Chepurny by introducing food additives into products in retail sales is not used, and the use of technological food additives to eliminate certain flour defects (low quality and quantity of gluten) to improve the quality of the finished product is not a falsification and does not require mandatory communication to consumers of all the features of the technological process.

Quantitative falsification takes place during the sale of packaged flour in a retail network. In addition, similarly to grain, quantitative falsification of flour is possible when it is sold in whole packages (bags) without re-weighing and opening the package by underweighting or pouring river sand or other substitute on the bottom of the package.

Flour quality evaluation.

Organoleptic indicators.

Determining the quality of flour by organoleptic indicators, their smell, taste, color, mineral impurities are taken into account.

Taste flour should be slightly sweet, without a bitter or sour taste. articulate sweet taste is not allowed, as it indicates that the flour was obtained from sprouted grain. The rancid and sour taste of flour indicates that significant changes in the chemical composition have occurred in it. The bitter taste of flour is reported by wormwood seeds that have fallen into the grain during grinding.

Smell fresh flour - pleasant, weak. Moldy, musty and other smells are not allowed. Foreign odors can appear in flour due to various reasons. So, musty and moldy odors indicate the poor quality of the grain from which the flour is obtained, or the staleness of the flour. The wormwood and garlic smell of flour is given by admixtures of wormwood and garlic. When the flour is affected by the smut, a herring smell appears in it. Foreign odors can turn into flour during transportation and storage in contaminated bags, as well as in wagons in which there were strong-smelling products. Some smells disappear when the bread is baked, others are transferred to it. Flour that has any foreign flavors and odors is not allowed for sale and baking.

The presence of mineral impurities determined by chewing. The feeling of crunching on the teeth when chewing flour is caused by crushed mineral impurities (sand, pebbles, etc.), which get into the flour if the grain was poorly cleaned. The feeling of crunching on the teeth is not allowed.

Colour depends on the type and grade of flour. According to the standard, each type of flour must have a certain color. So, white or white with a creamy tint should have varieties of extra and higher flour for baking wheat and types M 45-23; M 55-23; MK 55-23 general purpose wheat flour. White or cream color with a yellowish tint is typical for baking grains, and white or white with a yellowish tint is for baking flour of the 1st grade, as well as general purpose flour M75-23; MK 75-23; M 100-25. The presence of a certain amount of shell particles in flour of the 2nd grade gives the white color a yellowish or grayish tint. The same color is typical for general purpose flour M 125-20 and M 145-23. White color with a yellowish or grayish tint and clearly visible particles of grain shells. Higher grades of flour are always lighter, and lower grades are darker with the presence of shell particles. This makes it possible to quickly determine the grade of flour by comparing it with standards - samples of a certain grade. However, such a determination of the grade gives only an approximate result, since, in addition to the presence of shells, many other factors affect the color of the flour. Among them, the natural features of the grain are important: the content of pigments, the vitreousness of the endosperm, and even the mineral composition. The color of the flour also depends on the degree of grinding of the particles. So, fine flour, consisting of small particles, seems lighter than flour, consisting of larger particles that absorb light.

Physical and chemical indicators.

Moisture, whiteness, ash content, grinding size, quantity and quality of raw gluten (for wheat flour), the content of metal magnetic impurities, infection and contamination by pests of grain stocks are considered as physical and chemical indicators of flour. Moisture content of flour should not exceed 15.0%. This indicator is not only crucial for the storage of flour, but also affects the yield of bread. The whiteness of premium flour should not be lower than 54 conventional units of the device RZ - BPL, 1st - from 36 to 53, 2nd - 12-35. In wallpaper flour, it is not limited. The ash content of flour is an indicator of its grade. According to the requirements of the standards, it should not exceed,%: the highest grade - 0.55, the 1st - 0.75, the 2nd - 1.25, upholstery - 2.0%. The flour grinding size is of great technological importance, it is determined by sifting on the appropriate sieves. In baking, flour is valued, which has particles that are uniform in size and form it. In wheat flour, standards regulate the quantity and quality of raw gluten. The amount of gluten is determined by washing it manually or using a device, and the quality is determined by color, smell, elasticity, extensibility. The amount of raw gluten in premium flour should not be lower than 24%, 1st - 25, 2nd - 21, upholstery - 18%. The content of metal-magnetic impurities in flour cannot exceed 3 mg per 1 kg.

Infection of flour with pests of grain stocks is not allowed.

In flour, the permissible level of toxic elements (lead, cadmium, arsenic, mercury, copper, zinc), mycotoxins (aflatoxin B1, zearalenone, etc.), radionuclides and pesticides is normalized.

Chemical indicators. Humidity flour - an important indicator of its quality, determines the persistence of flour and its baking properties. The moisture content of flour should not exceed (in%): for rye and wheat - 15, soy - 9-10.

Ash content of flour characterizes the content of minerals in it. This indicator depends on the type of flour: the higher its grade, the lower the ash content. So, the ash content of wheat flour should be (in%, not more than): grains - 0.60, premium - 0.55, 1st - 0.75, 2nd - 1.25, wallpaper - 2.

size grinding characterizes the degree of grinding of flour. It is determined by sifting through silk sieves or wire mesh sieves with different mesh sizes. For example, for wheat flour it is allowed (in %).

Quantity and quality of raw gluten- an important indicator that determines the baking and pasta advantages of wheat flour. Gluten is an elastic mass formed from the swollen proteins of wheat flour when kneading dough from it. The amount of gluten in wheat baking flour should be (in%, not less than): in the highest grade - 28, in the 1st - 30, in the 2nd - 25, in the wallpaper - 20.

The quality of gluten is determined by color (light, gray, dark) and elasticity. With an increase in the gluten content in flour, such indicators of the quality of products from it as elasticity, looseness of the crumb and the volume of bread improve. Pasta improves surface condition, they become more durable.

Rye flour proteins do not form gluten.

Infection pests of grain stocks are not allowed. Content metal impurities should be no more than 3 mg per 1 kg of flour.

Safety indicators.

Safety requirements are stipulated by flour standards.

table 2

	The name of indicators	Metric Requirements
		not musty, not moldy
		not sour, not bitter
	The presence of mineral impurities	when chewed, there should be no crunch
	Metal-magnetic impurity, mg per 1 kg of flour; The size of individual particles in the largest linear dimension of 0.3 mm and (or) a mass of not more than 0.4 mg, no more
	Humidity, in %, not more than: flour from durum wheat and soft high vitreous wheat for pasta Flour for baby food (rice, buckwheat, oatmeal) For other types of flour
	Additional requirements for flour for baby food: Acidity, in degrees (0 T), not more than: buckwheat
	Acid number of fat in 100 gr. flour, mg KOH, no more

Conclusion.

In conclusion, I would like to say about the baking properties of flour. The baking properties of wheat flour are determined by the following indicators:

the color of flour and its ability to darken in the process of making bread;

structural-mechanical (rheological) properties of dough or raw gluten (flour strength) and the degree of their change in the process of testing;

water absorption capacity, i.e. the amount of water that is necessary to form a dough with optimal structural and mechanical properties;

gas-forming ability, i.e., the ability of flour to form during the fermentation of the dough (for a certain period) one or another amount of carbon dioxide;

autolytic activity, i.e., the ability to decompose complex flour substances into simpler water-soluble products under the action of flour's own enzymes.

The baking properties of rye flour are mainly determined by the state of its carbohydrate-amylase complex. Rye flour starch is less resistant to heat and hydrolytic processes than wheat starch.

Rye starch gelatinizes already at a temperature of 55 ° C; gluten starch is easily hydrolyzed by amylolytic enzymes.

Rye flour, even obtained from grain of normal quality, unlike wheat flour, contains active a-amylase, which causes starch dextrinization during bread baking. The grain of rye germinates more easily than the grain of wheat, and the autolytic activity at the same time reaches a value dangerous for the quality of bread. The crumb of rye bread with an increased content of dextrins becomes sticky, often there is a seal in it, voids appear. The crust of bread made from flour with high autolytic activity is dark, with cracks and undermining. Sometimes the crust lags behind the crumb.

To assess the baking properties of rye flour, autolytic activity is determined, since it characterizes the state of the carbohydrate-amylase complex, on which these properties depend.

The autolytic activity of rye and wheat flour is determined by the following methods: by autolytic test; by changing the viscosity of the water-flour suspension in various ways.

The autolytic activity of flour is expressed as the percentage of water-soluble substances in terms of the dry matter of the flour. The content of water-soluble substances is measured after heating the water-flour suspension under certain conditions favorable for the action of hydrolytic enzymes. The water-soluble substances formed in this case consist of dextrins, as well as products of protein hydrolysis and other complex flour substances.

The Hagberg method, which determines the falling number (viscosity index), is widely used in many countries to assess the autolytic activity and baking properties of flour.

The higher the autolytic activity of the flour, the lower the viscosity of the suspension and, accordingly, the lower the value of the falling number (in seconds). For rye wholemeal flour, the falling number must be at least 105 s, for peeled flour - 155 s.

The baking properties of rye flour also depend on the state of the protein-proteinase complex. The structure of protein substances and their hydrophilicity affect the viscosity of rye dough, but this dependence has not been studied enough. Significantly increase the viscosity of the dough carbohydrate mucus, the content of which in rye flour is significant. However, the effect of proteins and pentosans on the baking properties of flour has not been precisely established.

Bibliography.

Gavrichenkov D.N., Economics, organization and planning of flour and cereal production, M., 1957.

Gerasimova V.A. Commodity science and expertise of flavoring goods textbook for university students / V.A. Gerasimova, E.S. Belokurova, A.A. Vytovtov. - St. Petersburg [and others]: Peter, 2005. - 396 p.: ill.

Zharikova G.G. Microbiology of food products. Sanitation and hygiene: a textbook for students studying in the specialty "Commodity science and examination of goods" / G.G. Zharikov. - Moscow: Academia, 2005. - 299 p.

Kazantseva N.S. Merchandising of food products: Textbook. - M.: Publishing and Trade Corporation "Dashkov and K0". - 2007. - 400 p.

Kondrashova E.A., Konik N.V., Peshkova T.A. Merchandising of food products: Textbook. - M.: Alfa-M: INFRA-M, 2007. - 416 p.

Krishtafovich V.I. Methods and technical support of quality control (food products): tutorial: for students of cooperative higher educational institutions in the specialty "Commodity science and examination of goods (by areas of application)" / V. I. Krishtafovich, S. V. Kolobov. - Moscow: Dashkov i K°, 2006. - 122 p.:

Nikolaeva M.A. Theoretical basis commodity science: a textbook for universities: for students of higher educational institutions studying in the specialties "Commodity science and examination of goods" and "Commerce" / M.A. Nikolaev. - Moscow: Norma, 2006. - 437 p.

Timofeeva V.A. Merchandising of food products / V.A. Timofeev. Textbook. 5th edition, add. and Perer. - Rostov n / a: Phoenix 2005. - 416 p.

Nilova L.P. Commodity research and examination of grain and flour products: Textbook. - St. Petersburg: GIORD, 2005. - 416s. :ill.

Egorova G.A. flour technology. Grain technology. - 4th ed., revised. and additional - M.: KolosS, 2005. - 296 p.: ill. - (Textbooks and textbooks. Manuals for students of higher educational institutions).

Appendix.

Appendix 1

Quality indicators of wheat baking flour

Flour grade				Grinding size, %
					Passage through a sieve according to GOST 4403
			Not below the second group
				5 in N43 silk fabric or N45/50 polyamide fabric PA
Krupchatka	White or cream with a yellowish tint			2 of silk fabric N23 or polyamide fabric N21 FC-150	No more than 10.0 of N35 silk fabric or N36/40 polyamide fabric PA
			Not below the second group	2 in N35 silk fabric or N36/40 polyamide fabric PA	Not less than 80.0 N43 silk fabric or N45/50 polyamide fabric PA
	White with a yellowish or grayish tinge			2 in N27 silk fabric or N27 polyamide fabric	Not less than 65.0 of silk fabric N38 or polyamide fabric N41/43 PA
	White with a yellowish or grayish tinge with noticeable particles of grain shells	Not less than 0.07% lower than the ash content of grain before cleaning, but not more than 2.0%			Not less than 35.0 of silk fabric N38 or polyamide fabric N41/43 PA

Appendix 2

Quality indicators of wheat flour of general purpose

		Mass fraction of ash in terms of dry matter,%, no more	Whiteness, conventional units of the RZ-BPL device, not less than	Mass fraction of crude gluten, %, not less than	The quality of raw gluten, conventional units of the device idc	Grinding size, %			Number of fall, "PE", s, not less than
						The rest on a sieve in accordance with GOST 4403, no more	Residue on a wire mesh sieve according to ND, no more	Passage through a sieve according to GOST 4403, not less than
	White or creamy white				Not below the second group
						5 made of silk fabric N43 or polyamide fabric N 45/50 PA

	White or white with a yellowish tint					2 made of silk fabric N35 or polyamide fabric N 36/40 PA		80.0 of silk fabric N43 or polyamide fabric N 45/50 PA
	White or white with a yellowish tint					2 made of silk fabric N27 or polyamide fabric N27 PA-120		65.0 in silk fabric N38 or polyamide fabric N41/43 PA
	White or white with a yellowish tint					2 made of silk fabric N27 or polyamide fabric N27 PA-120		65.0 in silk fabric N38 or polyamide fabric N41/43 PA
	White with a yellowish or grayish tint					2 of silk fabric N27 or polyamide fabric N27 PA-120		65.0 in silk fabric N 38 or in polyamide fabric N 41/43 PA
								50.0 N38 silk fabric or N41/43 polyamide fabric PA
Note - The indicator "whiteness" of flour is valid instead of the indicator "ash content" at enterprises equipped with laboratory instruments and equipment in accordance with GOST 26361.

Chemical composition flour depends on the composition of the grain from which it is made, and on its variety. The higher the grade of flour, the more starch it contains. The content of other carbohydrates, as well as fat, ash, proteins and other substances, increases with a decrease in the grade of flour.

Consider the features of the quantitative and qualitative composition of flour. They determine its nutritional value and baking properties.

Nitrogen and proteins. Nitrogenous substances in flour mostly made up of proteins. Non-protein nitrogenous substances (amino acids, amides, etc.) are contained in a small amount (2-3% of the total mass of nitrogenous compounds). The higher the yield of flour, the more nitrogenous substances and non-protein nitrogen are contained in it.

Gluten composition. Raw gluten contains 30-35% solids and 65-70% moisture. Gluten solids are 80-85% composed of proteins and various flour substances (lipids, carbohydrates, etc.), with which gliadin and glutenin react. Gluten proteins bind about half of the total amount of flour lipids. Gluten protein contains 19 amino acids. Glutamic acid predominates (about 39%), proline (14%) and leucine (8%). Gluten of different quality has the same amino acid composition, but different structure molecules. The rheological properties of gluten (elasticity, elasticity, extensibility) largely determine the baking value of wheat flour.

Rye flour proteins. According to the amino acid composition and properties, rye flour proteins differ from wheat flour proteins. Rye flour contains a lot of water-soluble proteins (about 36% of the total mass of protein substances) and salt-soluble (about 20%). The prolamin and glutelin fractions of rye flour are much lower in weight; they do not form gluten under normal conditions. The total protein content in rye flour is somewhat lower than in wheat flour (10-14%). Under special conditions, a protein mass can be isolated from rye flour, resembling gluten in elasticity and extensibility.

Carbohydrates. The carbohydrate complex of flour is dominated by higher polysaccharides (starch, fiber, hemicellulose, pentosans). A small amount of flour contains sugar-like polysaccharides (di- and trisaccharides) and simple sugars (glucose, fructose).

Starch . Starch, the most important carbohydrate in flour, is contained in the form of grains ranging in size from 0.002 to 0.15 mm. The size, shape, swellability and gelatinization of starch grains are different for different types of flour. The size and integrity of starch grains affects the consistency of the dough, its moisture capacity and sugar content. Small and damaged grains of starch are saccharified faster in the process of making bread than large and dense grains.

Cellulose . Cellulose (cellulose) is located in the peripheral parts of the grain and therefore is found in large quantities in flour of high yields. Wholemeal flour contains about 2.3% fiber, and wheat flour of the highest grade contains 0.1-0.15%. Fiber is not absorbed by the human body and reduces the nutritional value of flour. In some cases, a high fiber content is useful, as it accelerates the peristalsis of the intestinal tract.

Hemicelluloses . These are polysaccharides belonging to pentosans and hexosans. In terms of physicochemical properties, they occupy an intermediate position between starch and fiber. However, hemicelluloses are not absorbed by the human body. Wheat flour, depending on the variety, has a different content of pentosans - the main component of hemicellulose.

Lipids. Lipids are called fats and fat-like substances (lipoids). All lipids are insoluble in water and soluble in organic solvents.

Fats. Fats are esters of glycerol and high molecular weight fatty acids. Wheat and rye flour of various varieties contains 1-2% fat. The fat found in flour has a liquid consistency. It consists mainly of glycerides of unsaturated fatty acids: oleic, linoleic (mainly) and linolenic. These acids have a high nutritional value, they are credited with vitamin properties. Hydrolysis of fat during storage of flour and further conversion of free fatty acids significantly affect the acidity, taste of flour and the properties of gluten.

Lipoids . Flour lipoids include phosphatides - esters of glycerol and fatty acids containing phosphoric acid combined with some nitrogenous base.

Pigments. Fat-soluble pigments include carotenoids and chlorophyll. The color of carotenoid pigments in flour is yellow or orange, and chlorophyll is green. Carotenoids have provitamin properties, as they are able to turn into vitamin A in the animal body.

Minerals. Flour consists mainly of organic substances and a small amount of mineral (ash). The mineral substances of the grain are concentrated mainly in the aleurone layer, shells and embryo. Especially a lot of minerals in the aleurone layer. The content of minerals in the endosperm is low (0.3-0.5%) and increases from the center to the periphery, so the ash content is an indicator of the flour grade.

Most of the minerals in flour consist of phosphorus compounds (50%), as well as potassium (30%), magnesium and calcium (15%).

In negligible amounts contains various trace elements (copper, manganese, zinc, etc.). Iron content in ash different varieties flour 0.18-0.26%. A significant proportion of phosphorus (50-70%) is presented in the form of phytin - (Ca - Mg - salt of inositol phosphoric acid). The higher the grade of flour, the less minerals it contains.

Enzymes. Cereal grains contain a variety of enzymes, concentrated mainly in the germ and peripheral parts of the grain. In view of this, high-yield flour contains more enzymes than low-yield flour.

Wholemeal flour has a lower digestibility and energy value, but a high biological value, it contains more vitamins and minerals.

Flour of the highest grades is poorer in useful substances, since they are concentrated mainly in the shells of the grain and the germ, which are removed when receiving flour, but are absorbed more easily and more completely.

Flour of the 2nd grade is obtained from soft wheat. The color is white with a yellowish-gray tint. Flour differs in the content of 8-10% shells, flour particles are larger than in the 1st grade, heterogeneous in size. Gluten content - not less than 25% ash content - not more than 1.25%. Flour of the 2nd grade is used in baking bread.

Wholemeal flour is made from soft wheat with single-grade wholemeal grinding without screening out bran. Flour yield - 96% Grayish-white color, gluten content - 20%, ash content, up to 2%. Used for baking bread.

Comparative characteristics of the nutritional value of various types of flour.

Nutritional value of flour.

The chemical composition of flour depends on the composition of the grain from which it is made, and on its variety. The higher the grade of flour, the more starch it contains. The content of other carbohydrates, as well as fat, ash, proteins and other substances, increases with a decrease in the grade of flour. Consider the features of the quantitative and qualitative composition of flour, determine its nutritional value and baking properties.

Nitrogen and proteins

The nitrogenous substances of flour are mainly composed of proteins. Non-protein nitrogenous substances (amino acids, amides, etc.) are contained in a small amount (2-3% of the total mass of nitrogenous compounds). The higher the yield of flour, the more nitrogenous substances and non-protein nitrogen are contained in it.

Wheat flour proteins

Flour is dominated by simple proteins - proteins. Flour proteins have the following fractional composition (in%): prolamins 35.6; glutelins 28.2; globulins 12.6; albumins 5.2. The average content of proteins in wheat flour is 13-16%, insoluble protein is 8.7%. The average content of raw gluten in wheat flour is 20--30%. In different batches of flour, the raw gluten content varies. wide range (16--35%).

The composition of gluten

Raw gluten contains 30-35% solids and 65-70% moisture. Dry substances of gluten are 80-85% composed of proteins and various flour substances (lipids, carbohydrates, etc.), with which gliadin and glutenin react. Gluten proteins bind about half of the total amount of flour lipids. Gluten protein contains 19 amino acids. Glutamic acid predominates (about 39%), proline (14%) and leucine (8%). Gluten of different quality has the same amino acid composition, but different molecular structure. The rheological properties of gluten (elasticity, elasticity, extensibility) largely determine the baking value of wheat flour.

Carbohydrates

Starch, the most important carbohydrate in flour, is contained in the form of grains ranging in size from 0.002 to 0.15 mm. The size, shape, swellability and gelatinization of starch grains are different for different types of flour. The size and integrity of starch grains affects the consistency of the dough, its moisture capacity and sugar content. Small and damaged grains of starch are saccharified faster in the process of making bread than large and dense grains.

Cellulose

Cellulose (cellulose) is located in the peripheral parts of the grain and therefore is found in large quantities in flour of high yields. Wholemeal flour contains about 2.3% fiber, and wheat flour of the highest grade contains 0.1-0.15%. Fiber is not absorbed by the human body and reduces the nutritional value of flour. In some cases, a high fiber content is useful, as it accelerates the peristalsis of the intestinal tract.

Hemicelluloses

These are polysaccharides belonging to pentosans and hexosans. In terms of physicochemical properties, they occupy an intermediate position between starch and fiber. However, hemicelluloses are not absorbed by the human body. Wheat flour, depending on the variety, has a different content of pentosans - the main component of hemicellulose.

Soluble pentosans or carbohydrate mucus give very viscous solutions, which, under the influence of oxidizing agents, turn into dense gels. Wheat flour contains 1.8-2% mucus, rye flour - almost twice as much.

Lipids are called fats and fat-like substances (lipoids). All lipids are insoluble in water and soluble in organic solvents.

Fats are esters of glycerol and high molecular weight fatty acids. Wheat and rye flour of various varieties contains 1-2% fat. The fat found in flour has a liquid consistency. It consists mainly of glycerides of unsaturated fatty acids: oleic, linoleic (mainly) and linolenic. These acids have a high nutritional value, they are credited with vitamin properties. Hydrolysis of fat during storage of flour and further conversion of free fatty acids significantly affect the acidity, taste of flour and the properties of gluten.

Flour lipoids include phosphatides - esters of glycerol and fatty acids containing phosphoric acid combined with some nitrogenous base.

The flour contains 0.4--0.7% of phosphatides belonging to the group of lecithins, in which choline is the nitrogenous base. Lecithins and other phosphatides are characterized by high nutritional value and are of great biological importance. They easily form compounds with proteins (lipo-protein complexes), which play an important role in the life of every cell. Lecithins are hydrophilic colloids that swell well in water.

Pigments

Fat-soluble pigments include carotenoids and chlorophyll. The color of carotenoid pigments in flour is yellow or orange, and chlorophyll is green. Carotenoids have provitamin properties, as they are able to turn into vitamin A in the animal body.

Minerals

Flour consists mainly of organic substances and a small amount of mineral (ash). The mineral substances of the grain are concentrated mainly in the aleurone layer, shells and embryo. Especially a lot of minerals in the aleurone layer. The content of minerals in the endosperm is low (0.3--0.5%) and increases from the center to the periphery, so the ash content is an indicator of the flour grade.

Most of the minerals in flour consist of phosphorus compounds (50%), as well as potassium (30%), magnesium and calcium (15%).

In negligible amounts contains various trace elements (copper, manganese, zinc, etc.). The content of iron in the ashes of different types of flour is 0.18--0.26%. A significant proportion of phosphorus (50--70%) is presented in the form of phytin - (Ca - Mg - salt of inositol phosphoric acid). The higher the grade of flour, the less minerals it contains.

Enzymes

Cereal grains contain a variety of enzymes, concentrated mainly in the germ and peripheral parts of the grain. In view of this, high-yield flour contains more enzymes than low-yield flour.

Wholemeal flour has a lower digestibility and energy value, but a high biological value, it contains more vitamins and minerals.

Wholemeal flour is made from soft wheats with wholemeal milling with single-grade grinding without screening out bran. Flour yield - 96% Grayish-white color, gluten content - 20%, ash content, up to 2%. Used for baking bread.

The average chemical composition of various types and varieties of flour, g / 100. table 1.

Product name

Carbohydrates

mineral

Vitamins, mg

Energy valuecall

Mono and disaccharides

Cellulose

Wheat flour:

Top grade

Whole wheat flour rich in vitamins and minerals such as: vitamin B1 - 33.5%, vitamin B5 - 12.1%, vitamin B6 - 20.4%, vitamin B9 - 11%, vitamin PP - 24.8%, potassium - 14, 5%, magnesium - 34.3%, phosphorus - 44.6%, iron - 20%, manganese - 203.4%, copper - 41%, selenium - 112.4%, zinc - 21.7%

Benefits of Whole Wheat Flour

Vitamin B1 is part of the most important enzymes of carbohydrate and energy metabolism, providing the body with energy and plastic substances, as well as the metabolism of branched-chain amino acids. The lack of this vitamin leads to serious disorders of the nervous, digestive and cardiovascular systems.
Vitamin B5 participates in protein, fat, carbohydrate metabolism, cholesterol metabolism, the synthesis of a number of hormones, hemoglobin, promotes the absorption of amino acids and sugars in the intestine, supports the function of the adrenal cortex. A lack of pantothenic acid can lead to damage to the skin and mucous membranes.
Vitamin B6 participates in the maintenance of the immune response, the processes of inhibition and excitation in the central nervous system, in the transformation of amino acids, the metabolism of tryptophan, lipids and nucleic acids, contributes to the normal formation of red blood cells, maintaining a normal level of homocysteine in the blood. Inadequate intake of vitamin B6 is accompanied by a decrease in appetite, a violation of the condition of the skin, the development of homocysteinemia, anemia.
Vitamin B9 as a coenzyme involved in the metabolism of nucleic and amino acids. Folate deficiency leads to a disruption in the synthesis of nucleic acids and protein, resulting in inhibition of cell growth and division, especially in rapidly proliferating tissues: bone marrow, intestinal epithelium, etc. Insufficient folate intake during pregnancy is one of the causes of prematurity, malnutrition, and congenital deformities and developmental disorders of the child. A strong relationship was shown between the level of folate, homocysteine and the risk of cardiovascular disease.
Vitamin PP participates in redox reactions of energy metabolism. Inadequate vitamin intake is accompanied by a violation of the normal state of the skin, gastrointestinal tract and nervous system.
Potassium is the main intracellular ion involved in the regulation of water, acid and electrolyte balance, is involved in the processes of nerve impulses, pressure regulation.
Magnesium participates in energy metabolism, synthesis of proteins, nucleic acids, has a stabilizing effect on membranes, is necessary to maintain homeostasis of calcium, potassium and sodium. Lack of magnesium leads to hypomagnesemia, increased risk of developing hypertension, heart disease.
Phosphorus takes part in many physiological processes, including energy metabolism, regulates acid-base balance, is part of phospholipids, nucleotides and nucleic acids, is necessary for the mineralization of bones and teeth. Deficiency leads to anorexia, anemia, rickets.
Iron is a part of proteins of various functions, including enzymes. Participates in the transport of electrons, oxygen, ensures the occurrence of redox reactions and activation of peroxidation. Insufficient consumption leads to hypochromic anemia, myoglobin deficiency atony of skeletal muscles, increased fatigue, myocardiopathy, atrophic gastritis.
Manganese participates in the formation of bone and connective tissue, is part of the enzymes involved in the metabolism of amino acids, carbohydrates, catecholamines; necessary for the synthesis of cholesterol and nucleotides. Insufficient consumption is accompanied by growth retardation, disorders in the reproductive system, increased fragility of bone tissue, disorders of carbohydrate and lipid metabolism.
Copper is part of the enzymes that have redox activity and are involved in the metabolism of iron, stimulates the absorption of proteins and carbohydrates. Participates in the processes of providing tissues of the human body with oxygen. Deficiency is manifested by violations of the formation of the cardiovascular system and skeleton, the development of connective tissue dysplasia.
Selenium- an essential element of the antioxidant defense system of the human body, has an immunomodulatory effect, is involved in the regulation of the action of thyroid hormones. Deficiency leads to Kashin-Bek's disease (osteoarthritis with multiple deformities of the joints, spine and limbs), Keshan's disease (endemic myocardiopathy), and hereditary thrombasthenia.
Zinc is part of more than 300 enzymes, is involved in the synthesis and breakdown of carbohydrates, proteins, fats, nucleic acids and in the regulation of the expression of a number of genes. Insufficient intake leads to anemia, secondary immunodeficiency, liver cirrhosis, sexual dysfunction, and fetal malformations. Research recent years the ability of high doses of zinc to disrupt the absorption of copper and thereby contribute to the development of anemia was revealed.

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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 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 differs not high energy bonds 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 a lower freezing point (up 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.