Kneading dough and education Kneading dough and education

Kneading dough and education

Testoobrazovaniya process is of fundamental importance, since it is preceded by a number of subsequent operations (forming, baking, decoration and so on. D.), In the preparation of specific finished products.
The structure of the baked goods is formed mainly on the testoobrazovaniya stage. The achievable homogeneity with test structures, the degree of ordering and thus the quality of the dough and finished products depend on the quality of the system, resulting in the formation of test patterns.
Basics testoobrazovaniya
For making pastry in the confectionery industry used different types of dough. Each type of test being prepared for its technology, provides the finished product with the desired properties.
The classification structure of the dough
By the nature of the structure of different types of dough of flour confectionery products can be divided into three main systems:
  • elastic-plastic-viscous system (protracted, galetnoe, cracker dough);
  • plastic-viscous system (sugar, shortbread dough);
  • semi-structured system (waffle, biscuit dough).
The first mandatory goal kneading operation - the formation of a homogeneous mass of the entire system consisting of flour, water, sugar, fat and other components.
Important in testoobrazovaniya process - forming the desired structure and test to obtain a system with desired properties.
At the beginning of kneading flour comes in contact with the water, sugar, fat, salt and other ingredients. At the same time the dough starts to happen a number of processes. The most important are the physical, colloid and biochemical processes.
Microbiological processes associated with the life of yeast and flour of acid in the process of kneading is not yet time to reach the intensity at which they could play a decisive role.
Each of the raw materials that make up the complex complicated test system plays a role in the process of testoobrazovaniya, but the most important is the basic raw material - flour, fat and sugar.
The impact on the process of flour testoobrazovaniya
In the production of flour confectionery products used primarily wheat flour of higher grades and I and for certain types of products - wheat wholemeal (Table 6.).
Table 6
Flour
Krupnota grinding%
Ash content,% on NE, max
gluten content,%, not less
Sieve residue (silk or wire)
Pass through a sieve (silk or wire)
number sieve
no more, %
number sieve
%
Wheat
the highest grade
43
5
0,55
28
| Sorts
35
2
43
0,75
30
|| Sorts
27
2
38
At least 60
1,25
25
wallpaper
067
2
38
At least 30
20
* No less than 0,07% lower ash content of grain before cleaning.
When kneading flour dough particles begin to rapidly absorb water, swell in this case. Clumping of swollen flour particles into a solid mass, which occurs as a result of mechanical action on the kneaded mass, resulting in the formation of the test.
The leading role in the formation of a dough with its inherent properties of elasticity, ductility and viscosity belongs to the proteinaceous substances of flour. Insoluble in water protein flour substances, which form gluten (gliadin and glutenin), bind in the test water not only adsorption (surface), but also osmotically. Osmotic swelling occurs as a result of diffusion of water molecules into the cell of the protein molecule. Osmotic binding of water mainly causes swelling of proteins. Gluten proteins can swell in cold water and hold water in an amount about 2-2,5 times its mass.
Swollen kneading proteins form a sponge dough "frame", which largely determines the specific physical properties test - its elasticity and extensibility.
This protein sponge structural framework is often called gluten.
The interaction of proteins with water consists of two main steps, is closely linked.
The first stage consists of swelling in the adsorption binding of water to form shells around water flour particles. Thus reaction of water with hydrophilic groups occurs not only on the surface of the flour particles but also inside them. The first step is exothermic swelling (ie, with heat release..) And the process is not accompanied by a significant increase in volume of the particles, since the amount of water bound in this manner - about 30%.
The second step is a so-called osmotic swelling happens as a result of inward diffusion of water molecules flour particles.
The second stage occurs without swelling heat release, but with a significant increase in the volume of the micelle, since the amount of water bound by such proteins is more than 200%. Most proteins, including gluten proteins are not uniform and are set different fractions with different molecular weight and different water absorption capacity.
Starch is the main component of quantitative part of the flour. The wheat flour contains about 70% starch. Therefore, the content, the state and properties of the starch substantially affect the physical properties of the dough and the "strength" flour.
"The strength of the flour" - The ability of flour to form a dough having after mixing and during subsequent processing certain physical properties.
"Strong" It called flour, capable of absorbing kneading dough normal consistency relatively large amount of water. The dough of the "strong" flour is very stable retains its physical properties in the process of mixing and further processing.
"Weak" flour believe that when mixing the dough normal consistency absorbs relatively little water. Dough made from this flour in the mixing and processing is rapidly changing its physical properties consistency in the direction of relaxation.
"Average" on the strength of flour by the described properties occupies an intermediate position between the flour "strong" and "weak."
Starch basically includes two carbohydrates: amylose and amylopectin.
Amylose is comparatively readily soluble only in warm water (over 40 ° C) to form a true solution. Amylopectin only dissolves in water when heated under pressure. Therefore, due to the solid structure of starch and its low solubility fraction of bound water therein is relatively small.
Starch flour soaked in water at room temperature can bind to adsorptive 35-40% moisture.
At higher temperatures and sufficient water binding starch with water increases.
The more in the grain and, correspondingly, in the starch flour, the lower the protein content and the "weaker" flour. However, the physical properties of the dough are affected not only by the starch content of the flour, but also by its properties, in particular, the dimensions of the starch grains and the degree of their damage when grinding the grain. The smaller the grain, the more specific their surface and the more water they will adsorbly bind to when forming the dough. This means that the dough made from flour with smaller grains of starch or a large percentage of its fine grains will be more viscous at the same water content. Whole grains of starch bind water mainly adsorptively, maximum to 44% on a dry matter, so their volume in the test increases very slightly. Damaged starch grains can absorb up to 200% of water. Due to the significant quantitative predominance of starch in flour (its content reaches 70%), moisture is bound almost equally by proteins and starch flour.
The test of a large output of flour, such as wallpaper, play a significant role, and particles of grain membranes in binding water (otrubistye particles), which bind moisture adsorption due to the presence in them of a large number of capillaries. That is why the moisture content of such flour increased.
Increasing the temperature and the presence of sufficient moisture contribute to the increase of starch to water bonding. At temperatures above 60 ° C and excess water takes place starch gelatinization process, ie. E. Distortion of the structure of starch granules and formation of a colloidal solution.
Starch moistened with water in any ratio and in any situation, does not form a bound test.
Corn starch particles swollen membranes and insoluble proteins are the "solid" phase of the test.
Along with the solid phase in the test has a liquid phase, which is a part of the water adsorption the non starch, proteins and particles of the grain shells. It contains water-soluble substances test - mineral and organic (water soluble proteins, dextrins, sugar, salts and others.).
Test liquid phase may be partly in the form of viscous liquid surrounding the solid elements (swollen proteins, starch grains and grain particles membranes). The wheat dough a significant part of the liquid phase can be absorbed osmotically swollen test proteins.
Along with the solid and liquid phases in the test has a gaseous phase. The gaseous phase arises through the capture and retention of air bubbles dough, which takes place in an atmosphere of kneading, and as a result of the fermentation process.
The influence of other primary commodities in the process testoobrazovaniya
Dough for pastry products besides flour contains water and other raw materials, particularly sugar and fat.
Sugar reduces the swelling of the flour proteins and has a significant impact on the test structure and the quality of finished products.
Sugar, affecting the taste and color of products, moreover, has the ability to limit the swelling, whereby it becomes possible to adjust the degree of swelling of protein and starch flour. Therefore sugar dough is a plasticizer.
Permissible deviations in the formulation of sugar in the dosage allow to take into account the properties of the flour and the temperature.
With an excess of sugar dough pieces spread out and acquire stickiness, resulting in dough from sticking to the laminating, forming mechanism, as well as the steel belt of the baking chamber.
The presence of large amounts of sugar in the dough products without fat gives excessive hardness.
Great influence on the dough quality products and has krupnota sugar particles. For a plastic dough, which severely restricted the water content should not use sugar, and powdered sugar. This is due to the fact that a relatively small amount of water may not dissolve all the provided formulation and the remaining amount of sugar crystals undissolved sugar cookies remain visible on the surface, which impairs its quality.
Fats are introduced into the dough and reduce swelling of colloids flour. Adsorption contacting the starch and proteins, fats block the possible coupling place of the colloidal particles weaken the mutual relationship between them and thereby prevent the penetration of moisture. This helps to reduce the elasticity and increase of plasticity of dough.
Depending on the type of fat and significantly changing mechanism plasticizing effect.
The biggest advantage have fats that preserve ductility at high temperatures. Typically, this is achieved in combination of hard and liquid fats with different melting temperatures. In this case, a small increase in temperature to melt only a portion of the fat, whereby the fat retains its plastic properties.
In the process of kneading the fat particles in the form of the finest films are distributed between the particles of flour, as if enveloping and lubricating them. When baking dough interlayer fat between the particles * flour promote the formation of porous structure and brittleness of finished products. The thinner the fat film and the more of them in the test, the more porous and brittle the structure will have the finished products. From this point of view, kneading a test on a dispersed, well-mixed emulsion, in which the fat is distributed in the form of minute droplets, significantly contributes to the formation of a good product structure. If the fat is collected in the test in the form of large droplets or balls, it does not envelop the particles of flour, it is poorly retained by products and is released from them during storage. So, for example, liquid vegetable oil behaves. Solid high melting fat has a high viscosity and low plasticity and is also poorly distributed among the particles of flour, gathering in large aggregates. Only fat, which has good plastic properties at certain parameters, namely fat, which retains plasticity in a relatively wide temperature range, is well distributed in the test.
The presence of fat in the finished product makes them crumbly and layered character. By increasing the amount of fat dough becomes loose, crumbly, and with a decrease - reduced ductility test, finished goods less crumbly.
The fineness of the fat has a great influence on the quality of products. The higher the dispersion of the fat injected into the dough, the more its influence. Therefore it is better to make the fat in an emulsified form.
Dairy products improve the ductility test and taste of products due to the presence in them is well emulsified dairy fat.
Egg products contribute to foaming and loosening test: yolk lecithin is a natural emulsifier, and egg albumin by good foaming properties gives the product porosity and promotes fixation structure. In addition, egg gives the product a pleasant taste and color.
Syrup, invert sugar and honey in the production of flour confectionery products are used to improve and make the surface Namokaemost products golden yellow color, which is due to decomposition of monosaccharides in the process of baking.
Certain properties of the dough are achieved by different processing conditions set and kneading raw materials in the formulation.
Adjusting the kneading process by introducing into the formulation of various amounts of sugar, fat and other ingredients, the dough can be obtained with predetermined physical properties.
The amount of water introduced into the dough, kneading the mixture temperature, the kneading duration also determine physical properties of the resulting dough. Changing technological factors (humidity, temperature, duration of mixing) and formulation in practice prepared pastry dough having a variety of properties, from uprugoplastichnovyazkogo for long cookies, crackers and biscuits to weakly structured liquid - wafer; of plastic for sugar and shortbread to downed saturated air biscuit dough.
The use of fat and sugar kneading creates conditions for a low humidity test, as it requires less water for the limited swelling of flour proteins.
Greater amounts of sugar and fat in the sugar test, low temperature and short kneading limit swelling of gluten proteins.
Kneading protracted, cracker and galetnogo test creates the conditions for a more complete swelling of the flour proteins and thus produce an elastic dough. This also contribute minimal amounts of sugar and fat in the formulations of doughs, high humidity and temperatures, and longer batch versus sugar test.
Biscuit and batter belongs to the group of semi-structured systems, and preparation of these types has its own specific test, sharply distinguishing features.
Biscuit dough is a dispersed system which comprises air bubbles, separated from each other by films of the dispersion medium very thin. The process of making biscuit dough is the introduction of air into the dough in a dispersed form. Thus there is a significant increase in weight (in 2,5-3 times), followed by the development of the inner surface of the system.
The structure of the biscuit dough - a highly concentrated dispersion of air in a medium consisting of egg products, sugar and flour. Therefore biscuit dough can be attributed to the foams.
Batter also relates to a semi-group systems. It should have a liquid consistency, which ensures the normal dosage and rapid distribution over the surface of the flat test wafer forms furnace. For batter liquid consistency creates technological conditions for kneading dough, limiting the coalescence of separate particles scattered flour gluten.
In respect of rheological batter - semistructured dispersion. Kneading dough are such that at the moment of contact with the fluid around each particle of flour formed hydrate shell, preventing convergence and coalescence of the swollen particles of gluten.
Influence of the basic technology factors the process of testoobrazovaniya
On the physical and structural and mechanical properties of the test is greatly affected production and technological factors, primarily temperature, humidity and duration of kneading.
HUMIDITY TEST
Humidity test depends on several factors, primarily the water absorption capacity of flour, sugar and fat in the recipe.
Flour water absorbing capacity - is the amount of water required for kneading the dough consistency optimal to enable normal handling of the test at all production phases.
Water absorbing capacity depends on the humidity of the flour, and outputs krupnoty grinding, as well as its content of proteins.
By lowering the humidity in the flour 1% water absorbing ability of flour increased by 1,8-1,9%. With the increase in flour yield water absorbing capacity increases.
The size of the flour particles and their dispersity also affect the water absorption ability of flour. The larger particles of flour and the heterogeneity of their composition, the lower the specific surface and the less water that binds flour for a certain period of time.
Much influenced by the sugar in the water absorption ability of flour. As the amount of sugar water absorbing capacity decreases flour. So when you add 1% sugar water absorbing ability of flour decreased by 0,6%.
When kneading dough should take into account the dependence of water absorption ability of flour of the main factors. This will most accurately determine the ratio of raw water for each test.
Indicative calculation of the amount of water required for kneading is carried out according to the formula
X - [100S / (100-A)] - B,
wherein X - the amount of water per batch in kg; C - weight of dry matter of raw material in kg; A - the desired test humidity,%; B - the mass of raw material per batch (without added water), kg.
In production conditions the dosage of water when mixing the dough should be specified for each class of products separately, depending on the formulation and the water absorption ability of flour.
Humidity control test carried out at the beginning of kneading, since the addition of water to flour or dough is formed already allow for uniform distribution of the added mass of feedstock in a test because of the fully formed structure of the dough.
Experimentally established humidity for each type of test, which varies depending on water absorption ability of flour, sugar and fat.
Humidity test each group of products depends on the formulations used. The dough prepared from flour, humidity lower than in dough prepared from flour of lower grades.
Within each category are also provided vibrations dough moisture, since the individual products are different varieties of sugar and fat.
TEMPERATURE TEST
The temperature has a significant influence on the process testoobrazovaniya, speeding up or slowing down the swelling of colloids flour. If necessary to increase the swelling of colloids flour, kneading was carried out at an elevated temperature if necessary to limit the swelling of the dough and to receive (for example, when the sugar dough kneading), the process is carried out at a low temperature raw material mixture.
For each type of test has its own optimum temperature.
So, for sugar and pastry optimum temperature 22-25 ° C for prolonged - 38-40 ° C for galetnogo and cracker - 32-35 ° C.
Treatment of the test, having a temperature of 32-40 ° C, should be carried out in a room where the air temperature is not lower than 20 ° C. At room temperature of about 15 ° C test surface temperature of about 40 ° C markedly worsens (becomes rough), which adversely affects the appearance of products. Therefore, when processing the dough in a cold room dough temperature should be somewhat lower than usual.
The desired temperature of the mixture can be given a prescription by adjusting the temperature of water or milk, going to the batch.
In order to determine the required heating temperature of the milk or water heat quantity calculated C? (In J), which should take away or add when mixing.
The quantity of heat is calculated using the following formula:
Q = mС (t1—t),
where m - mass of all raw material, kg; C - specific heat of the mixture of raw material, J / (kg-deg); t1 raw material mixture is a given temperature, ° C; t - temperature of the mixture of raw materials.
However, the theoretical calculation exceeds the amount of heat that should be made to achieve the desired test temperature. This is because in this calculation are not considered heat of hydration of proteins and starch flour, sugar heat of dissolution, heat generated when mechanical energy into heat by friction and the walls of the test blade kneader etc.
Practically it found that the amount of heat generated due to the above factors is approximately 15% relative to the amount of heat which should be made to the mixture to obtain the desired test temperature.
Therefore, in order not to complicate the calculations, the resulting value is multiplied by C} 0,85, and then divides.
The duration of kneading
The duration of mixing also has a significant influence on the properties of dough.
For the test with a pronounced uprugoplastichnovyazkimi properties (prolonged, galetnoe, cracker) the duration of mixing increases.
For plastic and sugar dough kneading reduce the duration to the minimum necessary for the uniform distribution of raw materials and producing the associated test.
The duration of mixing for the same type of test can vary depending on the gluten content of the flour, the raw material mixture temperature, humidity test, the design of blades and kneading machine frequency of rotation.
The formation rate of the test affect the content of the gluten in the flour, the dough moisture, temperature, and raw material mixing speed.
With increasing amounts of gluten in the flour mix protracted duration, and galetnogo cracker dough is reduced. At low levels of gluten in the flour must be more fully its swelling, which is achieved by a longer knead the dough.
Increasing the amount of moisture in the dough, ceteris paribus reduces the duration of the batch due to the more complete swelling of gluten.
The initial temperature of raw materials mixture also affects the duration of kneading, since temperature affects the swelling of flour proteins. Increasing the temperature of the initial mixture entails mixing acceleration test.
Increase blade speed kneading machine shortens batch. However, sugar is not recommended test excessively increase the frequency of rotation of the blades, as the test temperature rises rapidly, resulting in a dough tightened, t. E. In the test is reduced plastic and viscoelastic properties are increased.
Methods loosening test
In the confectionery industry for loosening the dough advantageously used three methods: chemical -
using different salts emitting gaseous substances in the test; Biochemistry - using baker's yeast; Physics, which uses carbon dioxide (carbonic acid gas) or air is injected into the kneading machine or shake up during testoprigotovleniya.
A chemical disintegration test method. The chemical leavening agents can be divided into three categories: alkaline, alkaline-schelochnokislotnye and saline.
By alkaline leavening agents include sodium bicarbonate (baking soda), ammonium carbonate (ammonium carbonate), and mixtures thereof; acidic to alkaline - mixture of sodium bicarbonate and crystalline food acids or their acid salts; to the alkaline salt - sodium carbonate and the mixture of neutral salts, for example a mixture of sodium bicarbonate and ammonium chloride.
The most commonly used on enterprises of alkaline chemical leavening agents: sodium carbonate (soda) and ammonium carbonate.
sodium bicarbonate NaNS03 is the most common chemical baking powder. Disintegrant manifests its action by heating when added to the dough leavening agent decomposes to release carbon dioxide from the following equation:
2NaNSOz = Na2С03+ N20 + С02.
sodium bicarbonate as a leavening agent has a number of disadvantages. The free form is released only 50% carbon dioxide. When the carbon dioxide generation is formed 63% sodium carbonate (by weight of sodium carbonate), which gives the product an alkaline character. The surface of the painted product with yellowish-pink, and acquire product specific taste.
Another most widely used disintegrant is ammonium carbonate (NH4)2С03. This disintegrant constitutes more gaseous products.
Ammonium carbonate decomposes when heated to release carbon dioxide, ammonia and water. The reaction proceeds according to the following equation:
(NH4)2С03= 2NH3 + С02 + N20.
ammonium carbonate completely decomposes in the oven with the release of about 82% of gaseous substances involved in the loosening of dough and a little more than 18% of water vapor.
A disadvantage of ammonium carbonate as a leavening agent is that the products remain in the warm state of ammonia odor.
With an excess of baking powder to the product for a long time there is a smell of ammonia.
When using sodium carbonate and ammonium carbonate mixture smell is less intense, while decreasing alkalinity products.
The advantage of these disintegrants is that Gaseous substances are basically not in the test, and in the products during baking. This allows the best use of ammonia and carbon dioxide products to loosen.
As a substitute of using ammonium carbonate salt NH ugleammoniynaya4НС03. Moreover, its dosage compared with ammonium carbonate increases by 30%.
The reaction proceeds according to the following equation:
NH4HCO3= NH3+ CO2+ N20.
Chemical leavening agents dosed depending on the properties of dough.
Thus, a sugar cookie varieties added 0,4% sodium hydrogen carbonate and ammonium carbonate 0,5%; in the long grades of cookies - respectively 0,7 and 0,08%.
In order to obtain products of normal porosity, chemical dosing allowed to vary depending on the disintegrants flour properties: (a disintegrant weight) on soda ± 15%. Reducing ammonia content should not exceed 50% of prescription rules.
Possible deviations from the usual doses of chemical leavening agent also possible to regulate the cookie mass required for machine wrapping. For example, to increase the mass of cookie accordingly increase the dose of sodium hydrogen carbonate and ammonium carbonate reduce the dose to decrease - lower soda dose and increase the amount of ammonium carbonate.
If it turns out cookies with swellings, change the dose of chemical disintegrants. In this case, an increased dose of chemical leavening agent eliminates this defect.
Bake cookies using is not recommended alone ammonium carbonate, since it gets an unpleasant sweet taste and a pale color, and as a result of the very rapid decomposition of ammonium carbonate products obtained macroporous.
Produced by the liver using a sodium bicarbonate is also impossible, since loosening would have to spend considerable amount. In this case, the alkalinity of the pastry is much higher than the permissible sanitary norms.
Additionally, sodium hydrogencarbonate biscuit surface stains yellowish-pink color and gives them a specific taste.
Along with alkali can be used kislotnoschelochnye disintegrators, which include sodium bicarbonate and any acid which allows fully decompose sodium bicarbonate and thus obtain a neutral reaction product.
Loosening test using baker's yeast. By loosening this test method utilizes yeast containing the complex of enzyme, the basic dough fermenting sugars and monosaccharides providing conversion into alcohol and carbon dioxide.
As a general rule, apply compressed baker's yeast species Saccharomyces cerevisiae.
Yeast are unicellular microorganisms with vegetable complex enzymes serving to convert sugars into alcohol and carbon dioxide according to the equation
С6Н1206-2С02 + 2С2Н50Н.
In the fermentation of yeast activity is greatly influenced by temperature. With increasing temperature accelerates the fermentation, however, the temperature rises more than 40 ° C should not be kneading dough, as at 45-50 ° C zymase (yeast enzyme) is inactivated, and the livelihoods of yeast is reduced.
To accelerate the fermentation can be by increasing the amount of yeast and sugar. However, this results in increased losses of dry matter of raw material resulting from the fermentation of sugar.
During the fermentation in the dough accumulates mainly lactic and acetic acid and traces of succinic, malic, tartaric, citric, and some other organic acid. The temperature optimum acid-forming bacteria test is about 35 ° C.
The mechanism of the yeast fermentation process is described in detail in Chapter VIII «Production of biscuits" - kneading yeast dough.
Physical test method for loosening. Physical test method for loosening air is provided by the introduction phase in the dough in the process of its preparation to shake up or kneading machines. As a result of this test is saturated with gas or air bubbles. During baking at high temperature, carbon dioxide and air bubbles expand, thereby forming porous articles.
Last modified on Tuesday, November 10 2015 06: 24
Vladimir Zanizdra

Founder Baker-Group.net site. More than 25-years of experience in the confectionery industry. More than 20-five years of management experience. Experience in the organization and design of the production from scratch. Site: baker-group.net/contacts.html El. mail This e-mail address is protected from spam bots. You need JavaScript enabled to view.

1 comment

  • Comment Abdurahman Abdurahman March 10, 2019

    Thank you very much for the knowledge with which you share with people. Cool site.

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