The main raw materials for the production of chocolate and cocoa powder are cocoa beans. Chocolate is a product of the processing of cocoa beans with sugar. Cocoa powder is a product derived from partially defatted cocoa beans. The fat (cocoa butter) obtained in the manufacture of cocoa powder is used in the manufacture of chocolate. Therefore, in the chocolate shops and cocoa powder is prepared.
chocolate manufacture
Chocolate is a product of the processing of cocoa beans with sugar, both without additions and with the addition of various flavoring and aromatic substances. Depending on the composition and quality of processing, chocolate is divided into the following groups:
- natural chocolate without additives;
- chocolate with additions.
Chocolate without additives and chocolate with additives is divided into dessert and ordinary. Dessert chocolate differs from ordinary high content of cocoa products and lower sugar content, as well as more fine grinding.
Chocolate with additives, depending on the added additives, is prepared of several types:
a) milk;
b) nutty (nut kernels or peanuts are added);
c) coffee (added organic coffee);
g) with waffles; d)
Fruit and others.
a) milk;
b) nutty (nut kernels or peanuts are added);
c) coffee (added organic coffee);
g) with waffles; d)
Fruit and others.
Chocolate glaze is a kind of unrefined chocolate and is used for glazing the bodies of sweets and other confectionery products.
Depending on the method of molding and the addition of fillings, chocolate is divided into slab, porous and chocolate with fillings.
Chocolate is a highly nutritious product, as it contains 55 — 60% carbohydrates, 30 — 38% fat, and 6 — 8% protein substances. Calorie chocolate about 5400 kcal.
The chocolate production process consists of the following main stages:
primary processing of cocoa beans;
pryhotovlenye grated cocoa;
cooking chocolate masses;
molding, wrapping and packaging of chocolate.
Primary processing of cocoa beans
The primary processing of cocoa beans consists of the following stages: sorting and cleaning cocoa beans from impurities; heat treatment of cocoa beans; cocoa bean crushing and cocoa shell separation.
Sorting and cleaning of cocoa beans. The cocoa beans entering the production contain a whole range of impurities: sand, pebbles, dust, burlap fibers, as well as glued beans (stuck together in the fermentation process), crushed and broken beans, and some other impurities, such as ferrous impurities.
Impurities impair the quality of chocolate and can cause equipment breakage, and the presence of broken and glued beans, as well as beans of unequal size, prevents proper heat treatment, since the glued cocoa beans (double and triple) will not be fried or not dried, and broken lines will be overcooked, which will affect the taste of chocolate. Therefore, cocoa beans are sorted. Sorting is desirable to produce in special rooms, and not in the premises of the shop, in order not to bring into the shop a chocolate moth. Sorting is done on sorting machines. Machines of various designs are used for sorting, and in particular a sorting machine with two selection conveyors (Fig. 19).
Cocoa beans are loaded into the machine's funnel, and then with the help of a bucket elevator they are fed into the machine's brushing mechanism, where they are cleaned of dust and other small impurities that are caught by the air stream and collected in cyclones. Next, the beans fall on flat screens, where the separation of small impurities and broken beans, which are displayed through special channels. Sorted cocoa beans pass over the magnetic apparatus, where ferro-impurities are separated, and are fed to two control conveyors for small and large beans, where the glued beans and large impurities are selected. These machines have capacities up to 0,8 t / h.
Currently, new sorting applied in theRSA-23 without control conveyors. In these machines, the cocoa beans are automatically sorted using sieves into small, large and broken beans, which are taken out of the machine through different channels. Skinny cocoa beans are separated by a powerful air stream. Small ferromagnetic impurities are separated with the help of magnets, and large metallic impurities and stones are separated.
Fig. 19. Sorting machine:
1 - funnel, 2 - bucket elevator, 3 - rotating brush, 4 - brush sector, 5 - suction fan, 6 - four-frame frame, 7 and 8 - conveyors, 9 - magnets.
social separators. The machine has a capacity of up to 1 t / h.
Depending on the quality of the cocoa beans, the amount of waste varies greatly. On average, when sorting mass grades of cocoa beans, the amount of waste is about 3%, of which up to 2,7% — broken and glued beans — are used in production, and 0,3% are unused waste (husks, dust, stones, chips and ferrous impurities). Thus, the yield of sorted cocoa beans is 97%. Sorted cocoa beans are heat treated.
To improve the taste and aroma of consumer varieties of cocoa beans, forastero, whose share in the world market is about 80%, a number of methods have been proposed abroad to improve the quality of these beans and their noble varieties of cocoa criollo. One of these methods, proposed in the GDR, is that the sorted cocoa beans are soaked in water and then treated with a weak solution of acids in water, after which the cocoa beans are dried in a special vacuum dryer.
Sorted beans are fed to the subsequent operation using a system of screws and bucket elevators, and for short distances using pneumatic conveying, but during pneumatic transportation, the beans are partially crushed.
Heat treatment of cocoa beans. Heat treatment of cocoa beans has a significant impact on their physicochemical properties. As a result of heating, a cocoa shell, a cocoa shell, is separated from the cocoa bean kernel, which is removed during crushing. After heat treatment, the moisture content is reduced from 6 — 8 to 2 — 2,5%, and cocoa beans become brittle and are easy to crush and grind. Under the influence of high temperatures, the taste is refined and the aroma of cocoa beans develops, volatile organic acids, such as acetic acid, are removed, with the result that cocoa beans become less acidic. The amount of water-soluble tannins is reduced by 2,0%, thereby softening the astringent taste of cocoa beans. When exposed to high temperatures, germ pests and microorganisms contained in cocoa beans die. Moisture loss during heat treatment is 4 - ^ - 6%. Heat treatment of cocoa beans is carried out in roasting and drying apparatus. Spherical (ball) and cylindrical devices are used from fryers.
A ball fryer (fig. 20) consists of a steel ball, rotating on a shaft, with blades for mixing the product to be fried. The ball is covered with a metal casing to reduce heat loss to the environment and has a feed funnel.
Roasting is carried out by hot gases resulting from the combustion of coke or gas in a special furnace. Other fuels, such as coal, are unsuitable for roasting, as the products of combustion of the fuel will give the cocoa beans an unpleasant taste.
Roasting takes place as follows: sorted cocoa beans with a bucket elevator are loaded into the funnel in portions of 60 — 150 kg, depending on the capacity of the ball; opening the valve from the funnel, the beans are poured into the bowl, through which hot gases with a temperature of 250 — 300 ° C are sucked through the fan. Cocoa beans are heated and quickly release moisture to the hot gases. Roasting continues 20 — 25 min.
Fig. 20. Ball fryer (scheme):
1 - funnel, 2 - rotating ball, 3 - refrigerator, 4 - air compressor, 5 - blades for mixing beans, 6 - burner, 7 - compressor electric motor, 8 - • fan for cooling, 9 - air supply pipe, 10 - pipeline for gas supply.
Regulation of the roasting temperature is achieved with the help of dampers on pipelines supplying hot gases. The temperature of the air leaving the bowl at the end of roasting is 160 — 170 ° C, the temperature of the beans should not be higher than 125 ° C. Roasted beans by turning the handwheel are poured into the refrigerator, where they are cooled by sucking the air to 35 — 40 ° C. high temperatures may cause decomposition of cocoa butter to form acrolein, resulting in a deterioration in the taste of the beans. The determination of the readiness of cocoa beans is made organoleptically. With the help of a probe, several beans are taken from the ball. The moisture content of roasted beans ranges from 2,5 — 3%.
Due to the direct contact of the cocoa beans with the combustion products, roasting in this apparatus is carried out evenly. At the present time, loading, turning on and off the device, as well as unloading the fried beans are automated at the confectionery factory. In addition to ball fryers, cylindrical fryers are used (Fig. 21). The fryer consists of a rotating cylinder. The front cover of the cylinder has a hopper for loading the cocoa beans. The lid can be opened as needed to
Fig. 21. Cylindrical fryer:
1 —- the blades for mixing the beans, 2 — the loading funnel, 3 — the cylinder, 4 — the lid.
unloading roasted beans. The rear wall of the cylinder has openings for steam and gases generated during frying. Heated cylinder produced by burning fuel in the furnace located under the cylinder. The fuel used is wood, coal, gas, and various wood waste.
The disadvantage of the apparatus is the long duration of roasting - 30 — 40 min — and less uniform roasting of beans as compared with the spherical apparatus, as well as the difficulty of temperature control.
The roasted beans are unloaded into a trolley with a mesh bottom and brought to a special fan, which sucks the air through the beans and cools them.
Roasting in fryers has a number of drawbacks: the frequency of operation of fryers, high frying temperature, which causes denaturation of proteins, partial decomposition of fat and loss of aromatic substances.
As the experience of foreign confectionery factories, as well as the work of the All-Russian Scientific Research Institute of Experimental Studies, showed, good heat treatment of cocoa beans is obtained in continuously operating dryers. Currently, VIS-2 dryers are used in confectionery factories in our country, which operate continuously. VIS-2 Dryer (general view and diagram of air movement dryer). The VIS-2 dryer is a vertical shaft of rectangular cross section, in which 20 rows of horizontal shelves are located, automatically turning at an angle of 90 ° at certain time intervals. Shelves begin to tilt upwards. Thus, the lower 20 row of shelves is first released, then the 19 row located above the 20 row, and cocoa beans are poured onto the vacant 20 row. Last of all, the shelves of the 1 row, which are filled with raw cocoa beans, are released. The dryer is loaded from the hopper with two belt conveyors. Cocoa beans come from the bunker to the top conveyor. The output of the beans from the hopper is controlled by the damper, which makes it possible to observe a certain thickness of the cocoa bean layer on the belt. From the upper conveyor, cocoa beans are transferred to the lower one, which with the aid of a carriage makes a reciprocating motion perpendicular to the movement of the shelves and along the shelves. This makes it possible to evenly distribute the beans over the entire area of the upper shelves.
The heat treatment of the beans is done with hot air blown along the shelves. As established by the work of the VNII, the optimum air temperature for drying 160 — 170 ° C beans. At a lower air temperature (140 ° C), a significant amount of acetic acid remains in the beans, which makes cocoa beans taste worse. At temperatures above 170 ° C, cocoa beans acquire a burnt aftertaste. Since the heating steam pressure in the confectionery factories usually does not exceed 6 ati, which corresponds to the temperature 164 ° С, the heating of air cannot be performed above 145 ° С. An electric air heater is installed to increase the air temperature, except for two steam heaters. The air passes successively through steam heaters, and then through electric air heaters and is heated to the required temperature.
The length of stay of cocoa beans in a dryer at an air temperature of 165 — 170 ° C — 57 minutes, but with a change in drying temperature, the duration of drying increases or decreases, respectively. Upon leaving the dryer, the beans, just like during frying, should be rapidly cooled. For this purpose, the dried beans using a screw and a bucket elevator are sent to the cooler, which is a vertical box with inclined shelves along which cocoa beans move by gravity, gradually moving downwards. The air is moving towards the beans with a temperature of 18 — 20 ° C, which cools them to 35 — 40 ° C. Currently, there is a VIS-42-DK dryer, in which 14 upper shelves serve to dry cocoa beans, and the lower six shelves to cool cocoa beans. The dryer control is automated.
Experiments on heat treatment of beans with high-frequency cocoa were conducted at the technological institute of the food industry. In this installation, drying is performed on a conveyor through which cocoa beans are continuously moving, irradiated from above and below by high-frequency currents using capacitors. Experiments have shown that this method makes it possible to produce cocoa beans with good taste and aroma. An electric induction method for drying cocoa beans is also proposed, consisting in the fact that the beans move inside steel pipes heated outside by an electric spiral.
Crushing cocoa beans. The cooled cocoa beans are sent to a crushing and screening machine, where the beans are crushed and the cocoa shells are separated. Cocoa shells are known to contain an insignificant amount of fat - from 3 to 5%, fiber 13 — 18% and ash 6,5 — 9,0%. The main nutrients are contained in the core. The presence of cocoa shells in chocolate and cocoa powder reduces the nutritional value and impairs the taste of the products, so the cocoa shells are removed when making grains. It should be noted that cocoa shells are hard to rub, even on modern machines. The grits obtained by crushing is a semi-finished product convenient for mechanical transportation and further grinding.
Bean crushing on a crushing and screening machine (Fig. 23) is performed as follows. Roasted and cooled cocoa beans from the 1 hopper using the 2 bucket elevator are passed through the 3 magnetic machine, which retains metallic impurities, and falls on the crushing rollers or 4 discs. Gap between rolls
Fig. 23. Crushing-sorting machine.
can be regulated. The crushed cocoa beans, consisting of a mixture of grains and cocoa shells of various sizes, fall on an 5 inclined sieve, which has a horizontal swing. The sieve has 6 or 7 individual sections with extruded grids, with hole diameters from 0,75 to 8 mm, which divide the crushed cocoa beans into an appropriate number of fractions. Each faction consisting of grains and cocoa shells, passing through the corresponding section of the sieve, enters the 7 channel. In the channels are installed inclined louvered partitions made of iron. When pouring crushed beans from one plane to another, a jet of air sucked in by the 10 fan separates the cockavel from the grains and carries it into the corresponding 9 channel. Purified grains, which have a higher specific gravity than cocoa shells, come out through the 8 hole, having previously passed magnetic devices.
The non-shredded and fine cocoa beans, which are more than 8 mm in diameter and therefore cannot pass through the sieve, are fed to the bucket elevator with the aid of the 6 auger and again get into the crushing rollers.
Depending on the degree of convergence of the crushing rollers or discs, the number of small nibs can decrease, and the number of large numbers can increase and vice versa. %
It should be noted that the finer the grains, the more cocoa shells are contained in it. In addition to cocoa shells, there is a certain amount of germ-germ in the grains, which contain only about 2,5% fat, 2,6 — 3,0% cellulose, have great hardness and are difficult to grind in cocoa mills.
Table. 17 present data output grits and its content of cocoa shells and germ (according VKNII).
Table 17
The yield of crushing and screening machine on fractions
| Rooms grit |
Diameter in mm sieve | Content in% | % Fat | Ash content in% | ||
| core | cocoa shells | rostkov | ||||
| 1 | 8 | 99,7 | 0,3 | 0 | 55,8 | 2,45 |
| 2 | 8 | 99,55 | 0,2 | 0,25 | 55,8 | 2,54 |
| 3 | 6 | 98,25 | 1,3 | 0,45 | 55,5 | 2,65 |
| 4 | 4,5 | 98,00 | 0,9 | 1,1 | 55,5 | 2,66 |
| 5 | 3 | 94,3 | 3,6 | 2,1 | 54,5 | 2,82 |
| 6
7 |
1,5
0,75} |
78 | 22 | 0 | 38,3 | 3,46 |
| 1-7 | average sample | 97,4 | 1,7 | 0,9 | 53,8 | 2,81 |
As can be seen from the above table, the larger the grains, the less it contains cocoa shells, and consequently, less ash and more fat. Krupko No. 4 and 5 contain from 1 to 2% sprouts, which, as mentioned above, have low nutritional value. At foreign confectionery factories, nibs No. 4 and 5 undergo additional cleaning on special machines in order to remove sprouts.
In the practice of Soviet confectionery factories for the preparation of slab chocolate and cocoa powder, nibs 1, 2 or 3 are used, as having a minimum admixture of cocoa shells and sprouts and containing the maximum amount of fat, and the smaller nibs — 4 no. glazes, candy masses and fillings.
For the preparation of the highest grades of dessert chocolate without additives and with additives, such as "Golden Label", "Our Brand", "Silver Label" and others, apply mixtures of grits secondary and higher grades of cocoa beans in the following proportions:
Krupka cocoa Aryba 4 parts
Grenada 1 part
Trinidat 1 part
Accra 1 part
Krupka cocoa Aryba 2 parts
Trinidat2 part
Accra 1 part
Cocoa nuggets are mixed in bins and then processed further. You can also mix grated cocoa. Mixing raw cocoa beans is rational, since beans of various varieties have different sizes and different thickness of cocoa shells, so roasting will be uneven.
The gravel yield on crushing and screening machines ranges from 88 to 88,8% based on the weight of roasted beans, and the yield of cocoa shells is 11,2 — 12%. As can be seen from the table. 18, kakavella is not identical in its composition. Small cocoa shells contain significant amounts of fat — 21 — 25%. This is explained by the fact that it contains an admixture of small grains, which are close in specific gravity to cocoa shells and are carried along with the latter by air.
Table 18. Output of cocoa shells by fractions
| room
cocoa shells |
Diameter of sieve opening in mm | Cockwella yield in% | The fat content in% |
| 1 | 8 | 74,9 | 3,5 |
| 2 | 8 | ||
| 3 | 6 | 16,1 | |
| 4 | 4,5 | 12 | |
| 5 | 3 | ||
| 6 | 1,5 | 6,5 | 21 |
| 7 | 0,75 | 2,5 | 25 |
| Total | 100 |
Small cocoa shell, containing a significant amount of fat, is used to make fatty glaze and to prepare a surrogate for cocoa powder.
Pryhotovlenye grated cocoa
Rubbing cocoa nibs. Cocoa bean cells contain cocoa butter, protein substances and starch grains. Cells have dimensions within 23 — 40 w / s, wall thickness 12 w / c.
The main purpose of the grinding process is to destroy the cell walls and release the cocoa butter contained in the cells. It is very important that the solid particles are well crushed, which depends not only on the design of the grinding machines, but also on the impurities of the cockawells, which are difficult to grind. It should be noted that cocoa mass is well transported by pumping and is better mixed with the other components of the formulation: powdered sugar and cocoa butter, compared to cocoa nibs.
Grated cocoa is made on eight-roll or three-roll mills with discs.
The eight-roll mill (Fig. 24) works as follows: cocoa nib from the hopper feed nut 1 feed roller through the 2 magnet to hold metal impurities is fed to the 3 and 4 grooves, 5, 6, 7, 11, 8, 3, 10, 10, 12, XMUMX, 13, XNUMX, XNUMX, XNUMX, XNUMX, XNUMX, XNUMX, XNUMX, and NNXX where further grinding is performed. The roll is removed from the roll with a knife, flows from the XNUMX receiving funnel and is captured by XNUMX, XNUMX, XNUMX rolls, which produce the final grinding of the mass. From the last roll of the XNUMX, the weight is removed with the XNUMX knife and enters the XNUMX collector with steam heating and a stirrer.
Grinding mass in the mill occurs as a result of a gradual increase in the number of revolutions of the rolls and a decrease in the gap between them. The first pair of grooved rolls has a gap 0,2 — 0,5 mm; the last pair — 10 — 20 microns. As a result of the friction, the rolls become very hot, so the last 6 rolls are made hollow inside and are cooled with water. The eight-roll mill gives a good grinding (90% of particles has a size less than 30 micron) with a performance of 200 kg / h. The moisture content of grated cocoa is 2 — 2,5%, the fat content is 55 — 56%, and the viscosity is 20 — 40 pz according to the Reutov instrument. Temperature 85 — 90 ° C.
A three-roll mill is a combination of a disc mill and a roller mill. Coarse grinding is performed using a pair of disks, of which one is stationary and the other rotates at high speed. Fine grinding of grains is achieved on three rolls, working on
the same principle as an eight-roll mill. The mill gives the same fine grinding. Capacity 150 kg] h
the same principle as an eight-roll mill. The mill gives the same fine grinding. Capacity 150 kg] h
In the process of operation, the mill rolls wear out rather quickly, as a result of which the degree of grinding of grated cocoa deteriorates. In addition, the mill rolls are reported to the grated
Fig. 25. Disc-pin mill.
Kao specific flavor, impairing the taste of chocolate products. Therefore, for the preparation of grated cocoa began to use disk-pin mills. Such mills are produced by the Swiss firm Schönenberger (Fig. 25).
The mill works as follows. The cocoa nugget from the 1 elektrodozatora passes through the 2 magnetic apparatus and through the 3 feed opening enters the 4 mill, where, as a result of the rotation of the disks with pins, it turns into grated cocoa and flows down. Disks do 6000 rpm. Air is supplied to cool the mill through the 5 pipeline. The heated air passes through the 6 water cooler, and then through the 7 fines trap, the 8 fan returns to the mill. The mill housing is water cooled. The mill has a capacity from 300 to 1250 kg! H, depending on the type of mill, and gives fine grinding of grated cocoa - particle size not more than 25 microns. The cocoa liquor from the mills is pumped into tempering collections (fig. 26), which are double-walled cylinders, between which waste steam and water are passed through. 
Inside the cylinder there is a mechanical stirrer for continuous mass mixing. The temperature of grated cocoa is maintained at 85 — 90 ° С. Collections are capacity from 1000 to 3000 l. Kneading the mass in tempering collections is necessary to prevent the precipitation of solid particles of grated cocoa and floating up the cocoa butter, resulting in different layers of grated cocoa having a heterogeneous structure. The tempering collections also process the cocoa liquor with alkalis. To calculate the consumption of raw cocoa beans on 1 tons of grated cocoa, you need to know the waste, waste and losses in the stages of making grated cocoa.
Inside the cylinder there is a mechanical stirrer for continuous mass mixing. The temperature of grated cocoa is maintained at 85 — 90 ° С. Collections are capacity from 1000 to 3000 l. Kneading the mass in tempering collections is necessary to prevent the precipitation of solid particles of grated cocoa and floating up the cocoa butter, resulting in different layers of grated cocoa having a heterogeneous structure. The tempering collections also process the cocoa liquor with alkalis. To calculate the consumption of raw cocoa beans on 1 tons of grated cocoa, you need to know the waste, waste and losses in the stages of making grated cocoa. Let's take the following losses, waste and waste (in%): sorting cocoa beans 1,5
roasting or drying cocoa beans 6,0
cocoa cooking grits
(crushing and refining cocoa beans) 12,0
preparation of cocoa liquor (grinding grits on roll
or other mills) 0,3
Calculation is carried out on 1000 kg cocoa liquor.
1. Determine the amount of cocoa nuggets for making 1000 kg of grated cocoa. Losses when grinding grains make 0,3%.
Х= 1000 * 100 / 99,7 = 1003 kg.
Determine the number of roasted cocoa beans for making 1003 kg of grains. Waste and loss during crushing is 12%.
X = 1003 * 100 / 88 = 1140 kg
Determine the amount of sorted raw cocoa beans to prepare 1140 kg of roasted beans. Ugar and loss account for roasting 6%.
X = 1140 * 100 / 94 = 1213 kg.
We determine the amount of unsorted raw beans for cooking 1215 kg assorted beans. Waste sorting and loss amount to 1,5%.
X = 1213 * 100 / 98,5 = 1231 kg.
According to standardized recipes, 1000 kg of raw unassorted cocoa beans is consumed on 1234,5 kg of grated cocoa.
Obrabotku grated cocoa alkalis. Processing grated cocoa with aqueous solutions of carbonate salts of sodium, potassium, ammonium, magnesium significantly improves the taste and aroma of chocolate and cocoa powder. In addition, the durability of the cocoa powder suspension is increased in the manufacture of the beverage. The improvement in taste and aroma is due to the fact that the solutions of these salts neutralize the acids contained in the cocoa beans and give a sour taste to chocolate and cocoa powder. In the presence of alkalis, there is a more intensive oxidation of tannins, forming complex high-molecular compounds, giving chocolate and cocoa powder a brighter color.
Especially great acidity and astringent taste have cocoa beans Bahia, as well as Accra and Cameroon. As a result of treatment with alkali, their taste qualities are significantly improved. Processing of grated cocoa from baya beans is a mixture NANSOS - 0,75% by weight of grated cocoa and MgSO3 - 0,12% by weight of grated cocoa. These salts dissolve in water, which is taken 2% by weight of grated cocoa. The solution is gradually added to the tempering tank with mixing. Then the cocoa mass is kneaded for 5 — 8 hours at 85 — 90 ° C.
Grated cocoa beans from Cameroon to Accra and processed on the same principle in the tempering machine K2WITH3 (0,6%) or NANOSE (1% by weight of grated cocoa). Potash and soda are pre-dissolved in water.
The cocoa liquor can also be treated with ammonium carbonate, and due to the release of ammonia, the treatment is carried out in vacuum kneaders or in tempering machines equipped with strong exhaust ventilation.
For the preparation of cocoa powder sometimes it is used to process grits K2WITH3 followed by standing in hot cells (languor) and frying.
The cocoa liquor from the tempering collections goes to the kneading machines for preparing chocolate masses or hydraulic presses to produce cocoa butter and cocoa cake.
Preparation of chocolate masses
Recipe chocolate masses. In compiling chocolate masses recipes are guided by the norms of content of grated cocoa and cocoa butter and sugar content in chocolate of various groups established by the MOUTH. So, for dessert chocolate without additions, the content of cocoa beans — grated cocoa and cocoa butter — is at least 45%, including grated cocoa at least 25%; sugar content is no more than 55%. In ordinary chocolate, without additions, the content of cocoa beans must be at least 35%, including the content of grated cocoa at least 20%; sugar content not more than 63%.
In dessert chocolate with finely ground additions, the content of cocoa beans components must be at least 30%, including cocoa liquor at least 16%, and sugar content not more than 55%. In ordinary chocolate with additions, the content of cocoa beans must be at least 20%, including grated cocoa at least 18%, and sugar content not more than 55%. Fat content in dessert chocolate 35 — 38% and in ordinary 30 — 33%. Chocolate glaze is close in its composition to dessert chocolate, but contains more fat (36 — 38%).
Usually, to reduce the viscosity of the chocolate mass and partly to soften the bitter taste that cocoa mass has, a part of the cocoa mass is replaced with cocoa butter.
The amount of cocoa liquor and cocoa butter in the formulation is calculated using the following formula:
HKT / 100 + (KB - KT) = M,
where: CT - the amount of grated cocoa;
X - fat content in grated cocoa in%;
KB - the content of the constituent parts of cocoa beans in chocolate (grated cocoa and cocoa butter in%);
M - fat content in chocolate in%. '
Example. You should prepare a mass for chocolate with a sugar content of 48% and fat 36%.
The fat content of cocoa grated X = 55%.
When the content of sugar 48% content of constituents of cocoa beans will be:
KB = 100 - 48 = 52%.
Substitute these values into the formula:
0,55KT + (52 - CT) = 36,
where the amount of cocoa mass CT = 35,5 kg.
Find the amount of added cocoa butter:
52 - 35,5 = 15,5 kg.
Sugar, which goes to the chocolate recipe, is mainly used in the form of powdered sugar, since powdered sugar is more easily rubbed on roller mills. For ease of transportation and uniform mixing, the icing sugar should be loose and not caked. The size of the powdered sugar does not exceed 80 microns.
Mixing components of chocolate mass. The mixing of the components of the chocolate mass recipes is carried out in batch kneaders. Universal kneading machines (fig. 27) with capacities from 250 to 500 l are used most often.
The body of the machine is steam heated. To unload the mass, the kneader can tilt.
The blades of the kneading machine are made of steel and are 2-shaped. The blades rotate in opposite directions. Raw materials - cocoa mass, cocoa butter and powdered sugar - according to the recipe are weighed and loaded into the machine. Cocoa liquor and cocoa butter are loaded at a temperature of 40 ° C. Not all of the cocoa butter is added, but about half of the recipe, the rest of the cocoa butter is added during billing. If chocolate is prepared with additives, then powdered milk, milk, dried with sugar, grated nuts, and coffee are added to the kneader according to the recipe. The kneading continues 10 — 15 min, and then the mass is unloaded and transferred to rolling.
Melangers (runners) can be used to mix recipe components (Fig. 28). This machine has a cast-iron rotating bowl with a granite bottom. Inside the bowl are suspended two cylindrical granite rolls, which by their weight roughly grind the mass. For better mixing inside the bowl there are fixed steel blades. Under the bottom of the bowl there is a steam battery. Currently, this machine is almost crowded out by kneaders of various designs due to the bulkiness and inconvenience of loading and unloading it. The machine is used in the manufacture of chocolate masses from cocoa nibs, as well as some types of nut candy masses.
The chocolate mass discharged from the kneading machines is a plastic mass with a fat content of 26 — 28%. But the chocolate mass is not ready yet, as it has rather large particles of grated cocoa - around 30 microns and even larger particles of powdered sugar - up to 80 microns, while dessert chocolate should have particles no more than 12 microns, and ordinary ones not more than 25 microns. Therefore, the chocolate mass is rubbed on the roll machines.
chocolate processing on roll machines. For grinding the chocolate mass, five-roll and three-roll machines are used. The most widely used are five-roll with rolls made of mirror cast iron. The five-roll consists of a frame, a feed hopper, five smoothly ground rolls, cooled inside with cold water, as the rolls get very hot, which can negatively affect the taste of the chocolate mass. The distance between the rolls is adjusted using the handwheels, by turning which you can change the distance between the rolls. The rotation speed of the rolls gradually increases and the distance between the rolls gradually decreases.
The first swath (lower) makes 20 rpm, the second - 48, the third - 96, the fourth - 153 and the fifth - 206. The direction of rotation of the rolls changes. If the first shaft rotates clockwise, the second is counterclockwise, and so on. The chocolate mass is loaded into the funnel of the machine, rubbed with rollers and, due to the difference in speeds, is transferred from one roll to another, from the last roll the mass is removed with a steel knife and falls into the substituted form. The principle of operation of the five-roll machine is visible from the diagram in fig. 29.
In the process of work, the middle part of the rolls gradually wears out, the machine starts to grind the mass badly, so the rolls have to be ground.
As already mentioned, the distance between the rolls is adjusted manually, which requires a high qualification from the roller, as even with the correct position of the rolls
Fig. 29. Five-roll machine with hydraulic adjustment of the work of the rollers (general view and scheme of work).
the distance between them is often determined by eye, which is reflected in the quality of the semi-finished product. The Italian company "Montanari" produces roll machines in which the distance between the rollers is changed by means of hydraulic adjustment, and the gap between the rollers is indicated by special devices (see fig. 29) -
The degree of grinding is judged by the size of the gap between the last pair of rolls (on machines with hydraulic adjustment of the rolls) or the percentage of particles smaller than 30 microns is determined by the method of Professor Reutov. The grinding degree of dessert chocolate without additions according to this method should be at least 96%, i.e., fine particles should be at least 96%. For dessert chocolate with additions, the grinding degree should be at least 95%, for ordinary at least 92% and for glaze at least 90%.
If the rolls are not worn, the mass is enough to pass once. When worn rolls weight is skipped at least two times for ordinary chocolate and three times for dessert chocolate, and the distance between the rolls decreases after each pass. The small size of grated cocoa particles and powdered sugar facilitate the process of rolling and provide an opportunity to get a finely ground mass with a single rolling. The chocolate coming out of the roll machine has a powdery appearance. This is due to the fact that as a result of rolling, the particle size decreases and the surface increases, as a result of which the fat contained in the chocolate mass is not enough to wet all the solid particles. Therefore, the chocolate mass is kneaded in kneading machines with the addition of cocoa butter. The first mixing of the mass with cocoa butter is called a crush. With triple rolling, the grinding is carried out after the second rolling, and after the third rolling, the final routing is carried out.
Keeping the chocolate in hot cells. The viscosity of chocolate masses depends not only on the fat content, but also on the amount of moisture. The less moisture contains chocolate mass, the less its viscosity. To reduce moisture, the chocolate mass after rolling is kept in hot chambers. To do this, the powdered chocolate mass from the rollers is collected in metal rectangular shapes with a capacity of 45 — 50 kg and placed in hot chambers — dryers with a temperature 45 — 50 ° C, where they are kept for 72 h. Then the mass goes to the rolling, wiring, and if necessary, for processing in finishing machines.
Curing in hot chambers is recommended for milky varieties of chocolate, which are prepared on dry or condensed milk, containing moisture much more than cocoa mass.
In foreign factories, vacuum dryers are used for this operation, in which not only excessive moisture is removed, but also volatile acids, which contributes to the improvement of the chocolai taste.
The layout of the chocolate mass. The distribution of chocolate mass produced in universal kneading machines with steam heating. The mass of chocolate processed on a roller machine and the second half of cocoa butter are added to the mixer according to the recipe. For a more uniform distribution of fat in the chocolate mass and to create a more durable emulsion, emulsifiers with the properties of thinners are added. Lecithin, which belongs to the group of phosphatides - complex organic compounds, is most often used as a diluent. Lecithin is found in soybeans and sunflower seeds. Soy lecithin is usually used as sunflower phosphatides impart an unpleasant taste to the products.
Lecithin has the properties of hydrophilic colloids - well swells in water. In addition, lecithin has lipophilic properties - it combines well with fats. Due to these properties, lecithin is used as an emulsifier-thinner in chocolate production. Thinner add 0,3% by weight of chocolate mass, which makes it possible to save up to 4% cocoa butter. The thinner is dissolved in cocoa butter heated to 50 ° C and then added to the kneader.
When distributing ordinary chocolate, aromatic substances, vanillin, essences and wine are added to the kneader. Crushed roasted nuts, waffles and candied fruits are added before shaping. After mixing well, ordinary chocolate and chocolate icing are considered ready and sent, respectively, to molding or glazing. When sending chocolate icing to other factories, the tempered chocolate icing is cooled with a thin layer on a rotating cooling drum with a diameter of 800 mm and removed in the form of thin chips with a knife. The drum is cooled inside with a cold brine with a temperature —10 — 12 ° C. The cooled icing is packed in a corrugated cardboard box and shipped to consumers. The glaze can be cooled also in large metal forms up to 50 kg, and then in the form of blocks is packed in boxes and sent to the consumer.
Good results are obtained by additional processing of masses for ordinary chocolate and chocolate glaze in emulsifiers used in the margarine industry. This method was proposed by VKNII and is used in a number of confectionery factories. The chocolate mass coming out of the rollers has dense lumps consisting of powdered sugar particles, cocoa liquor and cocoa butter. As a result of prolonged mixing or processing in the emulsifier, the lumps are broken, the oil contained in them is combined with the general fatty medium, as a result of which the mass acquires a homogeneous structure, the viscosity of the mass decreases by 3 times, which makes it possible to reduce the consumption of cocoa butter during spreading. Thus, according to research data, the viscosity of ordinary chocolate after processing decreases from 400 to 150 poz with a fat content of 33% and the viscosity of chocolate glaze decreases from 320-240 to 90 poz with a fat content of 33,5%. After spreading, the chocolate mass is continuously fed into the funnel of the emulsifier (Fig. 30) and, by means of an impeller, is fed into a disc with fingers rotating at a speed of 1420 rpm. Passing between stationary and rotating fingers, the mass is broken into tiny particles and leaves the emulsifier in the form of a stable emulsion.
Chocolate mass for dessert varieties of chocolate after the wiring is to be processed in finishing machines.
Production line preparation of chocolate masses. Cooking chocolate masses mechanized. However, the weighing and measuring of semi-finished products, the loading of raw materials into the kneading machine, as well as the transfer of semi-finished products to rolling and wiring was done manually. These operations required a lot of manual labor, a significant amount of inventory for the transportation of semi-finished products and created large losses of raw materials and chocolate mass.
As a result of the work of the VNII and engineering and technical workers of the Red October factory, 1956 created a production line for preparing chocolate masses, which currently works at a number of confectionery factories of the Soviet Union (Fig. Zo)
The granulated sugar is sifted through a sieve and from the 1 hopper is fed into the 2 dispenser consisting of a vertical auger and a hopper with a stirrer. The use of granulated sugar allows for more accurate dosing as compared to powdered sugar, which clotted in lumps and is difficult to dose. Replacing the auger with another, with a smaller or larger step, you can change its performance. 70 — 75 ° C melted cocoa from the 3 tempering machine is dosed into the 5 mixer using a twin 4 plunger pump, which also feeds cocoa butter to the 65 — 70 ° C mixer. cocoa.
The continuous mixer is a trough-shaped housing in which two parallel shafts with blades rotate. When rotating the blades towards each other
Fig. 31. The production line for the preparation of chocolate masses.
the other mass is intensively mixed and moves along the axis of the mixer. Pumps and mixer are steam heated. Mixing mass occurs during 20 min at a temperature 40 — 42 ° С. The mixture enters the five-roll 6 machine, where the mass is rubbed. The ground mass is fed to the 7 mixer, which differs from the first mixer by a large number of agitator turns — 100 per minute. The mixer is continuously fed the second batch of cocoa butter using the same 4 metering pump, as well as a thinner and essence. In the mixer, the chocolate mass is processed at a temperature of 55 — 60 ° C. Diluted chocolate from the mixer
Fig. 32. Horizontal finishing machine.
the mass is continuously fed to the emulsifier 8, where the homogenization of the chocolate mass occurs. The capacity of the line depends on the rolling capacity and ranges from 2 to 3 t per shift. The temperature of the chocolate mass leaving the production line is 65 ° C. The fat content is 32 — 34%. On the production line, plain chocolate and chocolate icing are produced.
Currently, production lines are being designed for making chocolate with additions and nut masses.
Finishing chocolate masses. Dessert types of chocolate, after rolling and spreading, are processed in finishing machines (conche machines). For finishing, mainly horizontal finishing machines are used (Fig-32). These machines have four or two troughs with capacities ranging from 250 to 500 kg. Currently, four-bed finishing machines with a trough capacity of up to 800 kg and a total capacity of 3200 kg are produced. The troughs have a concave cast iron or granite bottom. A granite roller with a reciprocating motion moves along the bottom of the trough. There is a space under the bottom where steam or hot water is passed to maintain the desired temperature of the chocolate.
The latest horizontal finishing machines chocolate temperature is automatically adjusted. These machines have devices for blowing air through chocolate. Unloading the finished mass is made through the hatches in the end walls of the troughs. During the operation of the roll, the semi-liquid chocolate mass is in motion all the time, so that the particles of grated cocoa and sugar continuously hit the end walls of the trough, the bottom and the roller, as well as the mutual friction of the particles and their vigorous mixing with the air.
The processing time of chocolate mass in horizontal finishing machines 48 — 72 h at temperature 65 — 70 ° С for chocolate without additions and for chocolate with milk at 45 — 50 ° С, since the taste of milk changes at high temperature. In the process of finishing there is a uniform distribution of cocoa butter in the whole mass of chocolate. Sugar particles after rolling have the appearance of very thin plates with sharp edges, in the process of finishing they are rounded and reduced in size. Grated cocoa particles are also rounded off and reduced. In the process of finishing, energetic mixing takes place - homogenization of the chocolate mass. In the process of processing, there is a partial transition of tannins in cocoa beans to insoluble or poorly soluble compounds, which reduces the astringent taste of chocolate. Volatile acids and mainly acetic acid, which give an unpleasant taste to chocolate, are partially removed. There is a partial removal of moisture. As a result of further grinding of grated cocoa particles and good mixing of the mass, diffusion of aromatic substances occurs, thereby developing the chocolate flavor. In the process of finishing the moisture content of chocolate is reduced from 1,2 to 0,6%. Due to the partial removal of moisture and good mixing of the mass in the first one and a half days, the viscosity of the mass decreases, and then the viscosity somewhat increases as a result of a decrease in particle sizes. It is very important that the chocolate mass is finely ground on the rolls before finishing. Then, as a result of the finishing, the chocolate mass gains good taste. The finishing process on horizontal finishing machines lasts three days and requires a significant amount of production space.
Studies show the process of finishing chocolate masses in horizontal finishing machines, the main role played by the impact of air on the chocolate mass.
At present, a number of new finishing machines, accelerating the process of finishing chocolate, have been proposed abroad. Such machines include the rotational vertical finishing machine of Petzold, or the so-called "vortex", installed in some factories of the Soviet Union. Such a machine (fig. 33) is a metal cylindrical tank with a jacket for heating and cooling the mass. The bottom has holes for mass draining. Inside the cylinder, a massive kneader lever and guide vanes rotate, stirring the chocolate mass. Through a special pipe with holes the mass is continuously saturated with heat.
Fig. 33. "Vortex" finishing machine Petzold.
air. As a result of vigorous mixing and particle strikes against the cylinder and blade walls, as well as air saturation, the finishing time is reduced to 7 — 9 h. On this machine, it is possible to finish chocolate masses with 28% fat content. Chocolate from finishing machines with the help of mobile pumps with filters is pumped into containers and fed to the molding.
chocolate processing on roll machines. For grinding the chocolate mass, five-roll and three-roll machines are used. The most widely used are five-roll with rolls made of mirror cast iron. The five-roll consists of a frame, a feed hopper, five smoothly ground rolls, cooled inside with cold water, as the rolls get very hot, which can negatively affect the taste of the chocolate mass. The distance between the rolls is adjusted using the handwheels, by turning which you can change the distance between the rolls. The rotation speed of the rolls gradually increases and the distance between the rolls gradually decreases.
The first swath (lower) makes 20 rpm, the second - 48, the third - 96, the fourth - 153 and the fifth - 206. The direction of rotation of the rolls changes. If the first shaft rotates clockwise, the second is counterclockwise, and so on. The chocolate mass is loaded into the funnel of the machine, rubbed with rollers and, due to the difference in speeds, is transferred from one roll to another, from the last roll the mass is removed with a steel knife and falls into the substituted form. The principle of operation of the five-roll machine is visible from the diagram in fig. 29.
In the process of work, the middle part of the rolls gradually wears out, the machine starts to grind the mass badly, so the rolls have to be ground.
As already mentioned, the distance between the rolls is adjusted manually, which requires a high qualification from the roller, as even with the correct position of the rolls
Fig. 29. Five-roll machine with hydraulic adjustment of the work of the rollers (general view and scheme of work).
the distance between them is often determined by eye, which is reflected in the quality of the semi-finished product. The Italian company "Montanari" produces roll machines in which the distance between the rollers is changed by means of hydraulic adjustment, and the gap between the rollers is indicated by special devices (see fig. 29) -
The degree of grinding is judged by the size of the gap between the last pair of rolls (on machines with hydraulic adjustment of the rolls) or the percentage of particles smaller than 30 microns is determined by the method of Professor Reutov. The grinding degree of dessert chocolate without additions according to this method should be at least 96%, i.e., fine particles should be at least 96%. For dessert chocolate with additions, the grinding degree should be at least 95%, for ordinary at least 92% and for glaze at least 90%.
If the rolls are not worn, the mass is enough to pass once. When worn rolls weight is skipped at least two times for ordinary chocolate and three times for dessert chocolate, and the distance between the rolls decreases after each pass. The small size of grated cocoa particles and powdered sugar facilitate the process of rolling and provide an opportunity to get a finely ground mass with a single rolling. The chocolate coming out of the roll machine has a powdery appearance. This is due to the fact that as a result of rolling, the particle size decreases and the surface increases, as a result of which the fat contained in the chocolate mass is not enough to wet all the solid particles. Therefore, the chocolate mass is kneaded in kneading machines with the addition of cocoa butter. The first mixing of the mass with cocoa butter is called a crush. With triple rolling, the grinding is carried out after the second rolling, and after the third rolling, the final routing is carried out.
Keeping the chocolate in hot cells. The viscosity of chocolate masses depends not only on the fat content, but also on the amount of moisture. The less moisture contains chocolate mass, the less its viscosity. To reduce moisture, the chocolate mass after rolling is kept in hot chambers. To do this, the powdered chocolate mass from the rollers is collected in metal rectangular shapes with a capacity of 45 — 50 kg and placed in hot chambers — dryers with a temperature 45 — 50 ° C, where they are kept for 72 h. Then the mass goes to the rolling, wiring, and if necessary, for processing in finishing machines.
Curing in hot chambers is recommended for milky varieties of chocolate, which are prepared on dry or condensed milk, containing moisture much more than cocoa mass.
In foreign factories, vacuum dryers are used for this operation, in which not only excessive moisture is removed, but also volatile acids, which contributes to the improvement of the chocolai taste.
The layout of the chocolate mass. The distribution of chocolate mass produced in universal kneading machines with steam heating. The mass of chocolate processed on a roller machine and the second half of cocoa butter are added to the mixer according to the recipe. For a more uniform distribution of fat in the chocolate mass and to create a more durable emulsion, emulsifiers with the properties of thinners are added. Lecithin, which belongs to the group of phosphatides - complex organic compounds, is most often used as a diluent. Lecithin is found in soybeans and sunflower seeds. Soy lecithin is usually used as sunflower phosphatides impart an unpleasant taste to the products.
Lecithin has the properties of hydrophilic colloids - well swells in water. In addition, lecithin has lipophilic properties - it combines well with fats. Due to these properties, lecithin is used as an emulsifier-thinner in chocolate production. Thinner add 0,3% by weight of chocolate mass, which makes it possible to save up to 4% cocoa butter. The thinner is dissolved in cocoa butter heated to 50 ° C and then added to the kneader.
When distributing ordinary chocolate, aromatic substances, vanillin, essences and wine are added to the kneader. Crushed roasted nuts, waffles and candied fruits are added before shaping. After mixing well, ordinary chocolate and chocolate icing are considered ready and sent, respectively, to molding or glazing. When sending chocolate icing to other factories, the tempered chocolate icing is cooled with a thin layer on a rotating cooling drum with a diameter of 800 mm and removed in the form of thin chips with a knife. The drum is cooled inside with a cold brine with a temperature —10 — 12 ° C. The cooled icing is packed in a corrugated cardboard box and shipped to consumers. The glaze can be cooled also in large metal forms up to 50 kg, and then in the form of blocks is packed in boxes and sent to the consumer.
Good results are obtained by additional processing of masses for ordinary chocolate and chocolate glaze in emulsifiers used in the margarine industry. This method was proposed by VKNII and is used in a number of confectionery factories. The chocolate mass coming out of the rollers has dense lumps consisting of powdered sugar particles, cocoa liquor and cocoa butter. As a result of prolonged mixing or processing in the emulsifier, the lumps are broken, the oil contained in them is combined with the general fatty medium, as a result of which the mass acquires a homogeneous structure, the viscosity of the mass decreases by 3 times, which makes it possible to reduce the consumption of cocoa butter during spreading. Thus, according to research data, the viscosity of ordinary chocolate after processing decreases from 400 to 150 poz with a fat content of 33% and the viscosity of chocolate glaze decreases from 320-240 to 90 poz with a fat content of 33,5%. After spreading, the chocolate mass is continuously fed into the funnel of the emulsifier (Fig. 30) and, by means of an impeller, is fed into a disc with fingers rotating at a speed of 1420 rpm. Passing between stationary and rotating fingers, the mass is broken into tiny particles and leaves the emulsifier in the form of a stable emulsion.
Chocolate mass for dessert varieties of chocolate after the wiring is to be processed in finishing machines.
Production line preparation of chocolate masses. Cooking chocolate masses mechanized. However, the weighing and measuring of semi-finished products, the loading of raw materials into the kneading machine, as well as the transfer of semi-finished products to rolling and wiring was done manually. These operations required a lot of manual labor, a significant amount of inventory for the transportation of semi-finished products and created large losses of raw materials and chocolate mass.
As a result of the work of the VNII and engineering and technical workers of the Red October factory, 1956 created a production line for preparing chocolate masses, which currently works at a number of confectionery factories of the Soviet Union (Fig. Zo)
The granulated sugar is sifted through a sieve and from the 1 hopper is fed into the 2 dispenser consisting of a vertical auger and a hopper with a stirrer. The use of granulated sugar allows for more accurate dosing as compared to powdered sugar, which clotted in lumps and is difficult to dose. Replacing the auger with another, with a smaller or larger step, you can change its performance. 70 — 75 ° C melted cocoa from the 3 tempering machine is dosed into the 5 mixer using a twin 4 plunger pump, which also feeds cocoa butter to the 65 — 70 ° C mixer. cocoa.
The continuous mixer is a trough-shaped housing in which two parallel shafts with blades rotate. When rotating the blades towards each other
Fig. 31. The production line for the preparation of chocolate masses.
the other mass is intensively mixed and moves along the axis of the mixer. Pumps and mixer are steam heated. Mixing mass occurs during 20 min at a temperature 40 — 42 ° С. The mixture enters the five-roll 6 machine, where the mass is rubbed. The ground mass is fed to the 7 mixer, which differs from the first mixer by a large number of agitator turns — 100 per minute. The mixer is continuously fed the second batch of cocoa butter using the same 4 metering pump, as well as a thinner and essence. In the mixer, the chocolate mass is processed at a temperature of 55 — 60 ° C. Diluted chocolate from the mixer
Fig. 32. Horizontal finishing machine.
the mass is continuously fed to the emulsifier 8, where the homogenization of the chocolate mass occurs. The capacity of the line depends on the rolling capacity and ranges from 2 to 3 t per shift. The temperature of the chocolate mass leaving the production line is 65 ° C. The fat content is 32 — 34%. On the production line, plain chocolate and chocolate icing are produced.
Currently, production lines are being designed for making chocolate with additions and nut masses.
Finishing chocolate masses. Dessert types of chocolate, after rolling and spreading, are processed in finishing machines (conche machines). For finishing, mainly horizontal finishing machines are used (Fig-32). These machines have four or two troughs with capacities ranging from 250 to 500 kg. Currently, four-bed finishing machines with a trough capacity of up to 800 kg and a total capacity of 3200 kg are produced. The troughs have a concave cast iron or granite bottom. A granite roller with a reciprocating motion moves along the bottom of the trough. There is a space under the bottom where steam or hot water is passed to maintain the desired temperature of the chocolate.
The latest horizontal finishing machines chocolate temperature is automatically adjusted. These machines have devices for blowing air through chocolate. Unloading the finished mass is made through the hatches in the end walls of the troughs. During the operation of the roll, the semi-liquid chocolate mass is in motion all the time, so that the particles of grated cocoa and sugar continuously hit the end walls of the trough, the bottom and the roller, as well as the mutual friction of the particles and their vigorous mixing with the air.
The processing time of chocolate mass in horizontal finishing machines 48 — 72 h at temperature 65 — 70 ° С for chocolate without additions and for chocolate with milk at 45 — 50 ° С, since the taste of milk changes at high temperature. In the process of finishing there is a uniform distribution of cocoa butter in the whole mass of chocolate. Sugar particles after rolling have the appearance of very thin plates with sharp edges, in the process of finishing they are rounded and reduced in size. Grated cocoa particles are also rounded off and reduced. In the process of finishing, energetic mixing takes place - homogenization of the chocolate mass. In the process of processing, there is a partial transition of tannins in cocoa beans to insoluble or poorly soluble compounds, which reduces the astringent taste of chocolate. Volatile acids and mainly acetic acid, which give an unpleasant taste to chocolate, are partially removed. There is a partial removal of moisture. As a result of further grinding of grated cocoa particles and good mixing of the mass, diffusion of aromatic substances occurs, thereby developing the chocolate flavor. In the process of finishing the moisture content of chocolate is reduced from 1,2 to 0,6%. Due to the partial removal of moisture and good mixing of the mass in the first one and a half days, the viscosity of the mass decreases, and then the viscosity somewhat increases as a result of a decrease in particle sizes. It is very important that the chocolate mass is finely ground on the rolls before finishing. Then, as a result of the finishing, the chocolate mass gains good taste. The finishing process on horizontal finishing machines lasts three days and requires a significant amount of production space.
Studies show the process of finishing chocolate masses in horizontal finishing machines, the main role played by the impact of air on the chocolate mass.
At present, a number of new finishing machines, accelerating the process of finishing chocolate, have been proposed abroad. Such machines include the rotational vertical finishing machine of Petzold, or the so-called "vortex", installed in some factories of the Soviet Union. Such a machine (fig. 33) is a metal cylindrical tank with a jacket for heating and cooling the mass. The bottom has holes for mass draining. Inside the cylinder, a massive kneader lever and guide vanes rotate, stirring the chocolate mass. Through a special pipe with holes the mass is continuously saturated with heat.
Fig. 33. "Vortex" finishing machine Petzold.
air. As a result of vigorous mixing and particle strikes against the cylinder and blade walls, as well as air saturation, the finishing time is reduced to 7 — 9 h. On this machine, it is possible to finish chocolate masses with 28% fat content. Chocolate from finishing machines with the help of mobile pumps with filters is pumped into containers and fed to the molding.