Categories
Raw materials and ingredients

Foams and blowing agents. The chemical leavening agents. (SK)

Characteristic foam-like substance

Foams are systems in which air or some other gas is a dispersed phase, and a liquid is a dispersion medium.

Foams are those systems in which the amount of the dispersed phase is large in volume and the gas bubbles are separated from one another by thin films of liquid.

Liquids consisting of only one chemical compound do not form foams.

For foams commonly used surfactants or high polymers, such as proteins.

In order for the dispersion medium to produce foam, it is necessary to form elastic, sufficiently strong films around the gas bubbles. The films can form surfactants both molecularly soluble and colloidal soluble.

The strength of the films is greater with colloidly soluble surfactants than with molecularly soluble ones.

In the confectionery industry, three-phase foam-like systems are used, which are formed by the liquid, solid and gaseous phases. Three-phase foam-like systems have the greatest resistance if the degree of dispersion of a solid substance is in the range between the colloidal solution and the coarse suspension.

The foaming ability is influenced by the following factors: the number of whipping whirlpools, the amount of gas to be passed, the duration and temperature of the churning, the concentration of the solution, the pH, the presence and dispersion of the solid phase, the amount of fat and alcohol.

Foaming agents

In the confectionery industry as a blowing agent is used egg whites, blood albumin, gelatin, soap root extract and licorice extract.

Weak protein hydrolysates are also suggested as frothers.

Egg whites

In the manufacture of confectionery products, fresh, frozen and dried egg whites are used as frothers, as well as canned sugar.

Composition in% egg white
Water 85-88
proteins 10-12
Sugar (glucose) About 0,5
Ash 0,66

Anhydrous egg white is dissolved in water at 17 ° in the amount of 15,35%.

Protein viscosity at 1 — 2 ° persists for about 5 months.

Fresh egg whites have a pH of 7,9, but when stored due to loss of carbon dioxide, the pH rises to 9,7. The coagulation temperature of egg protein 63 — 72 °.

Factors affecting the foaming capacity of proteins

Adding water. The foaming ability of egg whites when adding water gradually increases from 500 for egg whites without adding water to 1675 when the ratio of proteins to water is 20: 80.

Adding sugars. Adding sugars greatly reduces the foaming ability of egg whites. If some egg whites are taken, their foaming capacity is approximately 625. When 75% 35% sucrose is added, the foaming capacity is 287, when 75% 35% glucose is added, this capacity decreases to 251 and when 75% 35% invert is added, it drops to 237.

Foaming capacity is calculated by the formula

2.1

where: F - foaming ability;

u is the volume of the downed mass;

w is the volume of unstitched mass

The amount of protein added. Increasing the amount of dry protein from 1 to 2,25% of the total weight significantly improves the foaming of masses consisting of 100 g of powdered sugar and 100 g of apple sauce.

The foaming ability of the introduction of fat is greatly reduced (Table. 96).

Table 96. The specific gravity of the knocked down mass when adding products from cocoa beans with different fat content

Components Specific weight
Downed mass (64% sugar and 9% egg whites), control          0,51
Killed mass when adding cocoa mass in the amount of 15% at 40 °  1,05
Hit by weight after adding 15% of cocoa powder containing 23% fat 0,84
Hit by weight after adding 15% of cocoa powder containing 4,2% fat 0,60

Adding alcohol. When adding to the weight of the foam, consisting of 100 g apple puree, 100 grams of powdered sugar and egg whites g 2, 0,4% to alcohol penoobpazovanie not impaired.

The addition of sulfur dioxide. Introduction of up to 0,05 0,13% of sulfur dioxide to the mass of the weight has no effect on foaming.

blood albumin

Product albumin is a blood serum, dried in spray dryers.

Pasteurized, non-dried whey has little use.

The composition of bovine serum is given in Table. 97.

Table 97. Composition of bovine blood serum

Components Content in%
Water 91,34
Proteins    6,97
Fat  0,35
Fatty acid 0,07
lecithin 0,19
Cholesterol    0,09
Sugar    0,1

In the production of 2,5 marshmallow, parts of the blood albumin replace one part of the egg white in terms of dry matter.

Blood albumin may be used in the production of halva.

Gelatin

Gelatin is a mixture of animal protein. The best varieties of gelatin are derived from bone collagen. Good quality gelatin consists mainly of gluten. It also contains glucose. The more thoroughly microbially and the faster the process of obtaining gelatin is, the less glutoses are in it (Table 98).

Table 98. The amount of glutin and glucose in gelatin in%

Components gluten Gljutoza
The food is very good quality gelatin 68,0 12,5
Light, very transparent bone collagen gelatin 61,0 21,5
Technical gelatin     41,0 38,0
Low grade gelatin    13,5 68,0

Gelatin of good quality without smell and taste. In cold water, it swells, but does not dissolve, in hot water it dissolves. Gelatin does not dissolve in anhydrous alcohol and in volatile solvents. With tannins, it is quantitatively precipitated.

Table 99. Influence of adding different sugars on the foaming ability of gelatin sols

Composition Zola pH Foaming ability
3% ethyl rastvorzhelatina  4,43 530
* + 5% 

 

sucrose 

5,58 430
* + 15% 5,50 270
* + 25% 5,59 270
* + 15% Glucose 5,43 300
* + 15% 

 

invert ((100%)

5,07 330

* + 25%]

6,80 290
* + 25%     molasses (dry substance)   6,88   290

When cooling a solution containing more than 1% gelatin, jelly is obtained. The higher the glutose content in gelatin, the lower its gel-forming ability and the higher the foaming capacity.

Effects of the addition of different sugars on the foaming capacity sols seen from Table gelatin. 99.

Addition of egg whites to sols containing 3% gelatin, upon receipt of candy mass, does not change much the proportion of foamy mass, but its structure changes greatly: from the large cell, it becomes finely cellular.

Keeping the 3% gelatin solution at 60 ° for 30 minutes does not affect foaming ability.

Soap root extract

Soap root extract (Radix saponariae) is used as a frother in the manufacture of halva. Roots of the following two types growing in Ukraine and Central Asia are commonly used: Saponaria officinalis u Gipsophila stratium.

The extract of these soap roots has foaming properties due to the content of saponins in it. The number of saponins in the soap root from 4 to 15,5%. Saponins are heteroglucosides. They have a lot of surface activity.

Many saponins have hemolytic properties (dissolve red blood balls). The hemolytic effect of saponins is greatly impaired by sterols and lecithin if they are combined with saponins. Saponins are allowed to be administered only in halvah due to lecithin and sterols contained in it.

In tab. 100 is the foam height (in mm) obtained from 5 ml of saponin solution of different concentrations at 19 ° after 10 standard shaking for 20 seconds and after leaving the 2 for a minute in a cylinder with a diameter of 1 cm.

Table 100. The height of the foam column of aqueous solutions of saponin of different concentrations

Concentration

at %

The height of the foam column in mm Concentration% The height of the foam column in mm

4 * 10-3

6,7 100 * 10-3 78,5
8 * 10-3 11,5 150 * 10-3 80,5
16 * 10-3 29,0 250 * 10-3 82,0
40 * 10-3 56,5 500 * 10-3 82,5
60 * 10-3 56,0    

 

Licorice extract (licorice) root

Licorice is widespread in the wild in Uzbekistan, Tajikistan, Kazakhstan. Transcaucasia, the Volga region and the Crimea. The extract is obtained by leaching the root with water at a temperature of 70-80 °. This extract has a foaming capacity due to the potassium-calcium salt of glycyrrhizic acid contained in it.

In tab. 101 provides comparative data on the foaming ability of extracts of soap and licorice roots. The determination was carried out by shaking in a cylinder with a capacity of 100 cm3 for 2 minutes, after which the extract was allowed to stand for 1 minutes.

Table 101. Foaming ability of licorice and soap root extracts

Extract Foam height in mm

Soap root extract ud. weight 1,023

130

1% strength solution

0,5% strength solution

0,2% solution

0,1% strength solution

licorice root extract

141

135

115

98

Adding sugar syrup does not change the foaming ability of licorice extract. Licorice extract gives the product a specific taste. Boiled licorice extract gives the product a brown color.

Foam from milk proteins

The protein is hydrolyzed with dilute acids or enzymes (usually pancreatin). Properly prepared foaming agent is not inferior in egg-forming ability of egg white (in terms of dry substance).

Foam of whale meat and cod protein (VNIRO)

The protein is extracted with a solution of alkali, precipitated with acetic acid and washed with alcohol. This drug should be used in the same quantities as egg white (dry matter).

References

Golant B. Ya, chemical and technological foundations of the chocolate and confectionery production, ed. VNITI confectioners, 1941.

S.A.S.A. S., Application of Licorice Extract in the Confectionery Industry, “Confectionery Industry”, 1936, No. 5 — 6.

Kirk R. Е and О t h m е г D. F., Encyclopedia of Chemical Technology, vol. VI, The Interscience Encyclopedia Inc., New York. 1951.

Miles C. D., Journal of Physical Chemistry, vol. 49, p. 71, 1945.

Perri J. М., and Hazel F., Industrial and Engineering Chemistry, vol. 38, p. 549, 1946,

Chemical leavening agents

Chemical leavening agents are products that, when added> to the dough, emit gaseous substances.

Chemical disintegrators are mainly used for loosening dough containing a more or less significant amount of sugar, for example, for loosening dough in the manufacture of cookies, gingerbread and other flour confectionery products.

Chemical leavening agents are used to reduce the duration of the production process. Loosening on yeast takes several hours, on chemical baking powder — in the baking process. In addition, losses are reduced, since the leaching of yeast leads to the formation of carbon dioxide and alcohol due to sugars.

The chemical leavening agents can be divided into three groups.

  1. Alkaline baking powder. These include sodium bicarbonate (bicarbonate soda, sodium bicarbonate) and ammonium carbonate.
  2. Alkaline leavening acid. These include a mixture of sodium bicarbonate and acids or acid salts.
  3. Alkaline salt baking powder. These include mixtures of sodium bicarbonate and neutral salts, for example, a mixture of sodium bicarbonate and ammonium chloride.

Sodium bicarbonate

Sodium bicarbonate is used alone or mixed with other components.

Disintegrating effect of sodium bicarbonate based on the fact that when heated it decomposes to carbon dioxide release

2NaNSO3 Na =2С03 + N20 + С02.

1 g of sodium bicarbonate gives 132 ml of carbon dioxide at room temperature and atmospheric pressure.

The reaction takes place mainly in the furnace, and therefore the emitted carbon dioxide is well used to loosen the dough.

Sodium carbonate as a baking powder has several disadvantages: only 50% of carbon dioxide is released in its free form. When carbon dioxide is released, 63% of sodium carbonate (by weight of sodium bicarbonate) is formed, which gives the products an alkaline reaction.

Due to an excess of alkali, especially at high temperatures, the vitamins in the dough are destroyed.

ammonium Wglekïslıy

Ammonium carbonate decomposes when heated to release carbon dioxide, ammonia and water. The reaction proceeds basically according to the equation

(NH4)2С03 = 2NН3 + С02 + N20.

1 g ammonium carbonate yields (at room temperature and atmospheric pressure) 227 ml of carbon dioxide and ammonia 460 ml.

The resulting ammonia and carbon dioxide loosen the dough. From the point of view of the formation of gaseous products, ammonium carbonate is a good baking powder, as in the oven it gives 82% gaseous substances, loosening the dough, and a little more 18% water vapor.

The disadvantage of ammonium carbonate as a disintegrant is that the products in a warm condition retain the smell of ammonia. When working on a mixture of sodium bicarbonate and ammonium carbonate, the smell is less intense, but sodium carbonate remains in the dough and it has an alkaline reaction.

Alkaline leavening acid

In alkaline-acid baking powder source of carbon dioxide is sodium bicarbonate.

Acid salts are most often used for the release of carbon dioxide from sodium bicarbonate, but acidic salts, which in the dough before heating in a furnace, do not react with sodium bicarbonate, while the acids usually react even in the dough. The bulk of carbon dioxide should be released in the furnace. Depending on the thickness of the cookies and the properties of the dough (that is, depending on the time that the biscuits should be in the oven), carbon dioxide should be released either at the beginning of the baking process or somewhat later. Only in these cases, emitted carbon dioxide is well used. When it is released before the baking process, a significant part of the gas volatilizes without loosening the dough.

When using acidic components in stoichiometric amounts with respect to sodium bicarbonate, all of its carbon dioxide is released from it completely. Thus, to produce the same amount of carbon dioxide when working on alkaline acid baking powder, half the amount of sodium bicarbonate is required.

If the dosage of one disintegrant is known, then the dosage of the other can be calculated by recalculating carbon dioxide emitted.

Baking soda and kremortartar

Of the acid components is very good results kremortartar. Carbon dioxide is released almost exclusively in the furnace. The reaction proceeds according to the equation

NaNS03+ KNS4Н406→ С02+ Knasi4Н4О6+ N2О.

On one part baking soda asked 2,25 part kremortartara.

Depending on the ratio of cremetartarta and carbon dioxide of sodium, you can get cookies with an acidic, neutral and alkaline reaction. An alkaline reaction results in a cookie with better swelling. The taste of the products prepared on the specified baking powder is good.

Sodium bicarbonate and acid salt of pyrophosphoric acid

Good results are obtained with the introduction of acidic sodium or potassium salts of pyrophosphoric acid as the acid component.

Sodium pyrophosphate is obtained by heating a mono - sodium phosphoric acid salt for 6 — 8 hours at 200 — 220 ° with good stirring.

The reaction proceeds according to the equation

2NaN2R04 Na =3Н2Р207 + N20.

Upon receipt of sodium pyrophosphate, the temperature should not rise above 220 °, since otherwise the reaction may proceed further with the formation of the metaphosphoric acid sodium salt

Na2Н2Р207 = 2NаР03 + N20.

The reaction in the furnace with sodium bicarbonate proceeds according to the equation

2NaNSO3 Na2Н2Р207 Na =4Р207 + 2С02 + 2Н20.

1 g of sodium bicarbonate gives 264 ml of carbon dioxide at room temperature and atmospheric pressure.

The resulting normal sodium pyrophosphate has an alkaline reaction with respect to phenolphthalein, therefore, in order to obtain biscuits with a neutral reaction, sodium pyrophosphate is recommended to be administered in some excess

Sodium bicarbonate and calcium primary phosphate

Primary calcium phosphate, especially in highly milled form, does not give good results when used as an acid component, since it reacts with bicarbonate “atrium” before the baking process.

The reaction proceeds according to the equation

3SaN4(Р04)2 + = Are 8NaNSOz3(Р04)2 + 4Nа2NR04 + 8С02 + 8Н20.

Somewhat better results are obtained when using a granular product, since in this case the reaction with sodium bicarbonate proceeds more slowly.

Sodium bicarbonate and ammonium chloride

Sodium bicarbonate and ammonium chloride produce a good loosening effect, since when they are used, ammonia and carbon dioxide are completely released.

The reaction proceeds according to the equation

NaNSOz + NN4С1 = NаС1 + С02+ NN3 + N20.

The reaction occurs in the furnace is too late, so cookie has an uneven porosity and blistering on the surface. The smell of ammonia remains.

References

B and D a n o in the KX and Kotel'nikov SA, Manufacture of pastry goods Pishchepromizdat, 1953.

Kirk R. E. and Othmer D. F., Encyclopedia of Chemical Technology, The Interscience Encyclopedia Inc. New York, vol. II, 1948.

Add a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to combat spam. Find out how your comment data is processed.