Humidity of sand and protracted test
Shortbread and prolonged dough contains less water than galetnoe and, in particular, bakery dough. Similarly, shortbread dough and prolonged differ by having different amounts of water. The explanation for this should be sought particularly in that they contain fillers and different amounts of first sugar and fat, lowering water absorption capacity of flour. In addition, the water absorption capacity of the flour is influenced by a number of factors such as: humidity, output and krupnota flour milling, as well as the quantity and quality of proteins contained therein.
Water absorption ability of flour increased by 1,8-1,9% with decreasing humidity it to 1%.
Kuhlman cites , characterizing the ability of flour to bind water, depending on the flour yield (Table. 4).
|Variety of wheat flour and the percent recovery||Flour water absorption capacity (in %)|
|Soft Winter 85||54,12|
|Hard Spring 85||73,53|
|Soft spring 85||66|
The table shows that the water absorbing ability of flour increases with increasing flour yield, which, according to Kuhlmann, due to the presence of bran in the flour higher yields, with increased water-holding capacity.
Krupnota flour particles also has an effect on its water absorption capacity. The larger the flour particles, the smaller their specific surface area, which entails a reduction in the amount of water binding meal.
The quality of grain, which was prepared from flour, it also affects the water absorption capacity. Flour from frost grain absorbs 3-3,5 times more water than normal corn flour, which, in his opinion, should be attributed to the greater looseness micelles highly aggregated components of flour.
Sugar affect the amount and quality of the gluten and thereby its water-holding capacity. Present data showing the changes in the amount of gluten in the dough according to add flour to sucrose (table. 5).
|gluten Characteristics||Number of gluten (in assay %) adding sucrose to flour|
As can be seen from this table, the amount of gluten in the dough decreased with increasing amounts of sucrose. The most energetic acts sugar flour with strong gluten.
Studies biscuit VKNII laboratory, also showed that the water absorbing capacity of the flour and the amount of laundered gluten decreases with increasing the amount of sugar (table. 6).
|The percentage of sugar to flour||0||10||20||10||0||30||40||50||0||30||40||50|
|Water absorbing ability of flour (in%)||50||44||38||20||50||32||26||20||50||32||26||20|
|The amount laundered gluten (in %). .||37||37||36||30||38||38||34||34||37||35||34||32|
Effect of mono- and disaccharides on the properties of aqueous colloidal flour, and was found to have a dehydrating effect of sugar to flour colloids. The most dehydrating ability to have a disaccharide.
Thus, the sugar acting as a dehydrating agent and thereby reduce the swelling of flour proteins. This leads to a decrease in the water content of the gluten, which affects the amount of decrease in gluten laundered increasing the sugar content of the dough.
It is found that water absorbing ability decreases by flour 0,6% 1% by the addition of sugar. If the test to increase the amount of sugar at a constant amount of water in it, due to the dehydrating effect of the amount of colloid-bound water will decrease and water content located in the test in the form of a sugar solution - increase. The latter results in dilution of the test that is often observed in practice, the wrong dose of sugar.
The effect of fats on gluten meal is not fully understood. The addition of oleic acid in an amount of 0,5% of the weight of the flour makes the gluten crumbling during washing and only after a two to three hour stand it forms a coherent aggregate. It turned out that hydrochloric acid, added in an equimolecular amount, even slightly strengthens gluten. Thus, it has been established that the influence exerted on gluten refers to the specific action of those acids that are part of the fat of the flour. Moreover, it turned out that only unsaturated fatty acids act on gluten. With regard to saturated fatty acids such as stearic acid, and a number of neutral fats, they have no effect on gluten. Change in the state of gluten when adding unsaturated fatty acids
|flour varieties||The amount of gluten in the dough (in%) when added to the flour|
|sunflower oil||butter margarine||ghee|
|Flour 85% wheat; vaccum 49,3%; Crude gluten 33%||32||33||31||30|
|Flour 85% wheat; vaccum 50,1%; Crude gluten 42,2 % '||42||43||42||42|
|Flour 85% wheat; vaccum 51,3%; Crude gluten 34%||34||34||34||34|
|Flour 75% wheat; vaccum 52,9%; Crude gluten 42%||42||42||40||42|
|Flour 75% wheat; Water capacity 51,7%; Raw gluten 39,5%||-||38||38||39||38|
acids is due to a decrease in hydration capacity of gluten.
A number of researchers came to the conclusion that one of the most important properties of the fat is to reduce the gluten elasticity due to its adsorption on the surface of the micelles, thereby weakens the connection between them. It is assumed that a large number of unsaturated fatty acids increases the surface adsorption of proteins, fats. Introduction lard, oleic acid gives a more tender dough, due to the action of free fatty acids into proteins. The films formed on the surface of the protein micelles, slow down the penetration of water into the proteins.
Table. 7 the results of studies of the effect of fat to gluten.
Adding the sunflower oil does not appreciably reduce the amount of gluten, but it becomes less sticky and less extensible; adding more oil gluten breaks.
Adding 10% margarine improves the elasticity of gluten, without reducing significantly its quantity; presence 15-20% of margarine makes gluten loose and easily torn.
|Type of test||butter||margarine||margarine|
|Shortbread dough (zhira16% to flour)||with gluten in flour||32,5||32,5||34,2||34,2||32,5||32,5|
|with gluten in the dough||15,4||14,4||24,8||16,8||20,9||15,4|
|Protracted dough (10% of fat to flour)||with gluten in flour||31,7||31,7||33,8||33,8||21,7||21,7|
|with gluten in the dough||13||13,7||11,1||15||9,2||11,8|
Adding some more ghee reduces the amount of gluten. Gluten is softer, but less elastic.
Effect on gluten butter and margarine, and added to the molten cold and results obtained are listed in Table. 8.
When added to a shortcake dough fat melt, and the cold, the dough does not change its structure and the amount of gluten in the dough, the kneaded molten fat at slightly reduced. In a protracted test, prepared at the molten fat, the amount of gluten in all cases greater than the cold solid fat.
The role of starch in the dough mixing is extremely important. Pissarev believes excipients reduce the concentration of gluten in the dough, the dough cohesion and elasticity decreases. This opinion on the influence of starch on the amount of laundered gluten confirmed by the data in Table. 9.
|Addition of maize starch (at %)||The amount of gluten (in%)|
|flour with a high gluten content||flour with an average content of gluten|
Many researchers believe that the water absorbing ability of the gluten is inversely related to the amount of fillers and therefore starch is a reliable tool for controlling the properties of gluten.
Investigation of the effect of certain types of raw materials used in the quantity and quality of gluten and change its capacity. Here is a brief of these data.
gluten-free number is increased by the addition of milk, apparently due to its proteins. If you bring milk to supplement 30%, gluten quality deteriorates, and its moisture content is reduced.
Yeasts also increase the amount of laundered gluten, but gluten moisture content does not suffer while znachitelryh changes.
Salt reduces the amount of laundered gluten and reduce its moisture content.
Thus, when determining the ratio of raw material and water when mixing the dough should take into account water absorption capacity of flour, which, as we have seen, varies depending on many factors.
The basis of the humidity control as the sand, and a prolonged test is necessary to put the amount of gluten in the flour, the flour particles krupnotu, its moisture content and the amount of filler, reducing the moisture content.
To regulate humidity, a method can be recommended. It is based on the fact that the ratio of the moisture capacity of gluten to the moisture content of the dough produced by the standard recipe is almost constant. A number of coefficients or constants have been experimentally established for various types of test; For example, To a protracted test = 2,7-2,8 and To a short-baked dough varies, depending on the variety, from 3 to 4. Knowing this attitude and the moisture capacity of gluten, you can easily calculate how much water or milk you need to take for batching. For example, we give data (in%) on the moisture content of the dough depending on the moisture capacity of the gluten (Table 10).
|moisture content of gluten||Humidity test||moisture content of gluten||Humidity test|
The calculation of the water required for the test is made according to the formula: X = (100 * С) / (100-А) - В
where: X - the amount of water in liters per batch;
and - the desired moisture content in%;
a - the raw material weight per batch in kg (without milk and water);
c - weight of dry matter of raw material.
Simply use the ratio of dry to wet gluten, since there is a relationship between this ratio and the water absorption capacity of gluten. chart (. Figure 13) is made to simplify the calculations; it is suitable for prolonged humidity control test with a total content of fillers (sugar, oil, syrup, invert) in 30% by weight of the flour. Increasing the amount of fillers varies 1% humidity test 0,5% downwards, compared with the chart data and vice versa.
The ratio of dry to wet gluten
Fig. 13. Regulation prolonged humidity test.
Avoid generation test with extremely high humidity, which is sometimes dictated by the presence of flour with a high gluten content. B. this case, the amount of gluten should be reduced by any filler, preferably starch.
Regulation dough moisture is more difficult and responsible work, since the properties of this type of test does not allow excess moisture, because the dough while "prolonged", ie. E. Acquires the properties of a prolonged test. Due to the high concentrations of fillers is more energetic impact test on gluten than the protracted test and is therefore more fillers dosage responsible. Work of many researchers established the following additional fillers influence on the humidity test (Table. 11).
|Raw material to be added to the test||Reduced humidity test (in%) when added to the flour with a gluten content of crude|
|32 - 35||36 - 40||41- 45|
The calculations take the same chart (see. Fig. 13), where 30% fillers consist of 19% of sugar, 9% fat and 2% molasses.
Here is an example of the calculation.
Flour wet gluten contains 32,5%, dry gluten 12%; The ratio of dry to wet gluten anyway 2,7. According to the chart, we find that the dough with 30% of fillers should have a moisture content 25%. But we knead shortbread dough containing more sugar to 16%, fat at 8%, invert on 5% and maize starch to 5%, than in the test with 30% of fillers, but that does not have enough syrup. Amendment to the humidity will be:
(• 16 0,07) + (• 8 0,1) + (• 5 0,2) + (• 5 0,33) - (• 2 0,05) = 4,47- 4,5%.
Short pastry moisture will be 25 — 4,5 = 20,5%. The calculation of water consumption is the same as for the long test: X = (100 * C) / (100-A) - B
The studies humidity set for each type of test depending on the content of sugar and fat, flour, quantity and quality of gluten in the flour.
it is recommended to have the following humidity For pastry:
a) of the flour with medium gluten within
17- 18,5%, with gluten weak and bad - of up to 16 17,5%;
b) of flour I grade with the average quality of the gluten to 16,5 18%, with gluten weak and bad - of up to 16 17%;
c) flour grade II with the average quality of the gluten to 18 20%, with gluten from the weak and poor to 17 19%.
For a prolonged test is recommended to have the following humidity:
a) of the flour from the 22 to 26%, depending on the variety in the type of products;
b) of flour I grade on up to 25 26%;
c) flour of grade II to 25,5 27,5%.