Chocolate products, depending on the form, are divided into the following groups:
Chocolate without nachinok. This includes: a) Bar chocolate, chocolate tablets, chocolate figured (printmaking); b) shaped chocolates and c) aerated chocolate.
Chocolates with fillings: a) loaves with fillings; b) with assorted fillings.
The process of forming slab chocolate consists of the following stages:
- tempering the chocolate;
- pouring the chocolate into molds;
- cooling and planer molded chocolate from the molds.
Tempering chocolate. If chocolate after setting or finishing with temperature 45 — 50 ° С is cooled at ordinary temperature 20 — 25 ° С, then chocolate will have a coarse taste, due to the fact that the solid particles of cocoa mass and sugar contained in the chocolate mass are collected in a state of rest. large, cemented cocoa butter aggregates. In addition, on the surface of such chocolate a gray bloom forms, or the so-called fat “graying” of chocolate, which is a large cluster of large crystals of cocoa butter. The reason for this is that the cocoa butter is heterogeneous and incorporates four polymorphic (multiple) forms, of which three —ˠ, a and β'— are metastable, i.e. unstable, and one (β) is stable. Each of the forms can easily change into another under the influence of different temperature conditions. The cause of graying chocolate is the transformation of metastable forms of cocoa butter into stable.
In order to protect chocolate from fat bloom, it is necessary to create conditions under which cocoa butter begins to crystallize as a stable β-form before pouring it. Tempering is carried out with continuous stirring, in which nuclei of crystals and β-form crystals are formed. The optimum chocolate temperature is 29 — 31 ° C. The temperature of the chocolate also depends on the ambient temperature. The lower the temperature of the room where chocolate is molded, the higher the temperature of the chocolate must be and vice versa. Tempering is performed in tempering machines of various designs. The most common automatic screw tempering machines (Fig. 34). Screw tempering machine works as follows.
Chocolate mass with temperature 45 — 50 ° С through the 1 charging hopper with a water jacket and a vertical screw is fed into the filling opening of the 2 auger pipe. The screw-pipe is divided into three independent sections having water jackets. A screw auger is placed in the pipe; it has turns of small height, as a result of which the chocolate mass moves in a thin layer along the inner surface of the pipe and quickly perceives the required temperature from the pipe walls. To control the temperature at the end of the first and second sections of the screw installed. thermostatic cartridges associated with traction electromagnets that actuate the valves for supplying water to the section jackets. The shirt of the third section is tied into a common system with shirts on the pipes that discharge the tempered chocolate mass. With the help of a vane pump, heated water is supplied from the tank with the electric heater to the shirts. If it is necessary to stop the supply of chocolate to the dispenser or when
Fig. 34. The screw tempering machine.
chocolate wrong temperature by shutting the tap to the pipe outlet chocolate mass, it is sent back into the hopper of 3 pipe.
Forming slab chocolate is usually done on semi-automatic machines that perform the following operations: they pour chocolate into molds, process the spilled chocolate by the vibrating machine, cool the molded chocolate in the refrigerator, extrude the chocolate from the molds, and also heat the empty molds and serve them for pouring. In fig. 35 is a diagram of a slab chocolate molding machine.
Pouring chocolate into molds. Tempered chocolate, passed through a continuously operating filter, with a temperature of 30 ° C, is fed into the funnel of the casting machine (fig. 36) and poured into molds of bimetal, stainless steel, tinplate and other special alloys.
Capacity forms of 50 to 100 of
Forms must be heated to a temperature of 30 ° C. At higher or lower temperature forms will create unfavorable conditions for crystallization and fat bloom of chocolate will occur. The dosage of chocolate in the form produced by the volume, which corresponds to a certain weight. Depending on the design of the unit, it simultaneously fills from 2 to 12 forms moving along a belt conveyor or mounted on a chain conveyor.
The unit depicted in the figure simultaneously fills 6 single row forms for tiles weighing 100 g or 12 single row forms 50.
Spilled chocolate enters the vibrating conveyor, which is a tray that, under the influence of eccentrics, oscillates per minute from 650 to 1000. Forms with chocolate slowly move along the compacting vibrating conveyor, chocolate fills well all the cavities of the form, the small air bubbles contained in chocolate are removed, with the result that the chocolate becomes dark in color and shiny surface. Chocolate molds are on the 3 — 5 min. Vibrating conveyors create strong noise in the workshops. Pictured in fig. The 35 unit has a silent vibrating conveyor.
Cooling of chocolate. The chocolate processed on the vibrating conveyors should be rapidly cooled, since slow crystallization, large cocoa butter crystals form and fat bloom of chocolate occurs. Therefore, chocolate molds are cooled in refrigerators at 5 — 8 ° С for 30 minutes. The refrigerator compartment is a cabinet up to 22 m in length, inside of which a conveyor with molds filled with chocolate moves.
Fig. 36. Machine for molding of chocolate in the form:
1 - feed hopper, 2 - mouthpieces, 3 - pistons for mass ejection in shape.
The cooling of the air in the cabinet is carried out with the help of batteries, inside which cold brine is circulated, which is supplied from the refrigeration unit.
Since the cooling horizontal cabinets with single-belt conveyors are of considerable length, now multi-tiered horizontal conveyors have been used. Such a conveyor, shown in Fig. 35, provides the movement of the forms fixed on the conveyor, first in one direction, then in the opposite direction. In addition, vertical cooling cabinets are used, in which the forms on the lifts go up and then go down the second branch.
The cooled chocolate is knocked out of the mold with the help of a mechanism. Forms with chocolate are rotated 180% special beat hit the bottom of the form, with the result that the tiles easily fall out of the forms, as the cocoa butter decreases in volume when cooled. Empty forms are placed on a special conveyor, heated and fed to the forming machine. Chocolate bars are placed in the production container, each row being replaced by paper, or transferred to the wrapping along the conveyor belt.
It is very important that the temperature of the air in the punch and wrapping room does not exceed 15 — 18 ° С, since at a higher room temperature, moisture from the air will decrease on the surface of the chocolate, which will dissolve the sugar on the surface of the chocolate. When the moisture evaporates, the sugar will begin to crystallize in the form of large crystals and a gray patina will appear on the surface of the chocolate - sugar grated chocolate.
Sugar bloom can occur when chocolate is cooled in refrigerated cabinets at temperatures below 5 ° C.
In small enterprises, chocolate is molded by hand.
Forming chocolate with fillings and shaped chocolate. Hollow figures and chocolate with fillings, such as chocolate loaves and patterned chocolate with fillings, are molded on automatic machines (Fig. 37).
Forming chocolate with fillings as follows. Empty heated molds are poured with chocolate in the apparatus /, after the 2 mold is passed through the shaking conveyor, the 3 mechanism is tilted to 180 °, while most of the chocolate (about 75%) flows out of the molds and a thin layer of chocolate remains on the mold walls. The thickness of the layer can be adjusted by changing the speed of the centrifugal mechanism. Forms in the upturned position are fed to the cooling conveyor 4, where they are cooled at a temperature of 8 ° C. On the transverse conveyor 5, the forms are stripped of chocolate drips and placed on the conveyor 6, where the crust is further cooled. The molds are then transferred by the cross conveyor to the filling machines for the 10 fillings. For a quick transition from one type of filling to another, several such devices are installed. The filling is not filled to the top, so that the surface can be filled with chocolate. Forms filled with filling go to the 5 vibrating conveyor, where the filling is compacted, and then to the vertical 11 cabinet with the temperature 18 — 20 ° С, where the filling is cooled.
From the form cabinet, the conveyor is fed under electrical heating, where the edges of the chocolate crust are heated to better mix with liquid chocolate and sent to the 12 enrobing machine, where they are poured with chocolate on top. Chocolate-filled molds are mechanically trimmed of excess chocolate and sent to a vertical 13 cabinet, where they are cooled at a temperature of 8 ° C. Frozen chocolate is knocked out of the forms on the 14 mechanism and placed in boxes. Blank forms are transported using the 15 cross conveyor and 16 conveyor belt to the filling machine.
The following types of toppings are used to prepare chocolate with fillings: fondant-cream, nutty, chocolate-cream, fruit-marmalade and other fillings. Hollow figures are made on the same machine, but for their production forms are used, consisting of two halves on hinges, and each half of such a figure is a mirror image of the other. After processing in the centrifugal mold mechanism, they are manually closed and cooled on a cooling conveyor. After cooling, the forms are manually opened and the figures are removed from the forms.
The figured automat takes up a large area of the workshop and at the same time has a relatively small productivity — from 50 to 400 kg! H and requires a significant number of workers for maintenance.
Currently, a number of foreign companies began to produce universal machines for molding chocolate products.
Abroad, universal automatic machines of the Danish company Osted for the production of chocolate bar, chocolate with fillings and shaped chocolate have become widespread. The machine takes up less space than that described above, and all processes are fully mechanized and automated. The machine has a capacity of up to 1000 kg / h and is serviced by three workers.
Preparation of porous chocolate. The chocolate mass for aerated chocolate is prepared in the same way as for dessert chocolate without additions. The mass from the finishing machines enters the tempering machines, where it is brought to a temperature of 30-32 ° C, and then poured into molds heated to 30 ° C. The mold is not poured completely, but at a 3D height, that is, only 100 g is poured into a mold with a capacity of 75 g. After that, the molds are placed on a vibrating conveyor, where they are processed for a short time, and then they are placed in a vacuum chamber in which a vacuum is maintained 725 mmHg Art. Under the influence of rarefaction, the air bubbles contained in the chocolate increase in volume, and along with them, the chocolate, which fills the entire form, also increases in volume. In order for the chocolate to cool during the increase in volume, troughs with water are installed in the vacuum chamber, as a result of which the temperature in the chamber is maintained at 21-23 ° C. After cooling for 15-20 minutes, the chocolate is removed from the vacuum chamber and placed in a refrigerator. cabinet with a temperature of 5-10 ° C for final cooling, then beaten out of the molds and sent to wrapping.
In addition to natural slab chocolate, the confectionery industry produces peanut and soy chocolate, which is made not from cocoa beans, but from roasted peanuts or soybeans and in which instead of cocoa butter is added confectionery fat.
Chocolate wrapping and packing
The wrapping of slab chocolate and chocolate loaves is made on wrapping machines in a waxed or sub-parchment roll, aluminum foil and a colorful label. Tiled chocolate and chocolate loaves are wrapped in a label in the form of a parcel and in an envelope. Small tiles are wrapped in an envelope. Aluminum foil and spinning protect the chocolate from moisture, and therefore, from sugar graying, as well as from the loss of flavor.
Chocolate pieces are wrapped in cellophane or foil. Assorted with fillings stacked in boxes of 250 — 500.
Wrapped chocolate is placed in cardboard cases weighing 2 — 2,5 kg, and then in tesov or plywood boxes.
Ready chocolate contains the following amount of moisture: dessert and ordinary no added no more than 1,2%, With finely ground additions - dessert no more than 1,2% and ordinary no more than 1,5%.
Ash content insoluble in 10% hydrochloric acid, not more than 0,1% in all types of chocolate.
The total content of cellulose in chocolate without additives is no more than 3% and in chocolate with finely divided additions of not more than 4%.
The degree of chocolate grinding according to Reutov (particle content less than 30 micron): dessert chocolate without additions - no less than 96%, ordinary without additions - no less than 92%, with finely ground additives of dessert - not less than 95%, and ordinary - no less than 92% .
Production of cocoa powder
Cocoa powder is a finely ground product obtained from partially degreased grated cocoa and is used as a beverage. Cocoa powder is obtained from the cacao cake, which is a waste of production in the manufacture of cocoa butter.
Cocoa powder, unlike other beverages, such as tea, coffee, contains little extractive substances that are soluble in water, so it does not give the infusion, but forms a strong suspension in water - a suspension that should not settle to the bottom during 2 minutes.
To obtain a solid suspension, it is very important that the particles of cocoa powder be small. The smaller the particle size of the powder, the more slowly it precipitates. The cocoa liquor, from which cocoa powder is produced, must be prepared from grains from No. 1 to No. 3, i.e., have a minimum amount of cocoa shell impurity, which gives a precipitate. It is also very important that the degree of grinding of grated cocoa is not less than 90% (according to Reutov), which also affects the quality of the suspension.
The use of smaller nibs 4 or 5, containing sprouts, gives low quality cocoa powder, as the sprouts have a specific weight of 1,4, and the cotyledons are 1,1. Consequently, pounded sprouts that have a larger specific gravity than pounded particles of cotyledons will quickly precipitate during the manufacture of the drink.
To obtain a more durable suspension, some types of cocoa powder, such as the “Extra” and “Our Brand” varieties, are made with processed alkalis. Processing, as already described above, is subjected to grated cocoa. In addition, processing of cocoa nibs (К2CO3) is performed. Underdried or lightly fried grains are soaked with a solution of potash for 40 min, then aged in hot chambers with a temperature of 50 — 60 ° С for 72 h, after which it is subjected to secondary drying and roasting—
When processing with alkalis, the stability of the beverage suspension is increased, as a result of the formation of a small amount of fatty acid salts, which are strong emulsifiers, which slow down the sedimentation of the smallest solids of cocoa in the drink.
Cocoa powder is produced with a fat content of at least 17%. In addition, a low-fat powder is produced that contains at least 14% fat. Preparation of cocoa powder is carried out according to the following technological scheme:
- pressing cocoa mass - obtaining cocoa cake;
- Grinding and pressing of cocoa powder;
- Packaging and packaging of cocoa powder.
Pressovanye grated cocoa. Grated cocoa, blended in tempering collections, sent with temperature 85 — 90 ° С to hydraulic presses, where cocoa butter is pressed. The most widespread are six-sided hydraulic vertical automatic press machines, and more recently, horizontal automatic automatic press machines.
The six-press automatic press (fig. 38) works as follows. Heated bowls are automatically filled with grated cocoa. As soon as the bowls are filled, the cocoa feed pump automatically shuts off, as indicated by the light signal. The pressing process starts by turning on the pump that supplies the working fluid — engine oil — to the press cylinder. Pressing takes about 25 minutes and ends at a pressure of 300 ati. After that, the cake is automatically pushed out of the cups, and the process begins again. Cake contains from 14 to 17%, fat.
The cocoa butter yield is 44 — 47% based on the weight of grated cocoa. The yield of cocoa butter depends on the fat content of the cocoa cake, the fat content in cocoa liquor, as well as the moisture content, degree of grinding of cocoa liquor and pressing temperature. The less fat remains in the cake, the greater will be the yield of cocoa butter, and vice versa. The more fat contains cocoa mass and the higher the grinding degree, the greater the oil yield. The greater the moisture content of grated cocoa, the higher its viscosity, the lower the yield of cocoa butter.
Horizontal hydraulic presses work on the same principle, but with greater pressure (540 ati) and make it possible to get cocoa cake with a content up to 7% fat, and therefore, to increase the yield of cocoa butter, necessary for chocolate production, to 50%. Horizontal presses have 12 or 22 bowls.
The yield of cocoa butter can be determined by the following formula:
X = 100 (M-y) /100 —y '
where: X - the output of cocoa butter in%;
M - fat content in grated cocoa in%;
y is the fat content in oil cake in%.
y is the fat content in oil cake in%.
Fig. 38. Vertical press machine.
If cocoa mass contains 55% fat, and 17% fat cake, then the cocoa butter yield will be:
X = 100 (55- 17) / 10017 = 3800 / 83 = 45,8%
The resulting cocoa cake is cooled to a temperature of 30 — 35 ° C and transferred to crushing.
Cocoa butter is used for making chocolate.
Grinding and sifting cocoa powder. Grinding aggregates are used for grinding and sifting cocoa powder. The unit performs the following operations: preliminary
Crushing the cacao cake into pieces, grinding the previously crushed cocoa cake and sifting the cocoa powder.
Cooled to 30 — 35 ° C, cocoa cake is served in a cake mill, which is crushed into pieces the size of a walnut. Shattered cocoa cake samotaysk served in bins, working alternately. From the bunkers, the crushed cake enters the disintegrator, in which the crushed oil cake is crushed into powder. Cocoa powder is served in a sifting machine.
In a sifting machine, cocoa powder is divided into two fractions: fine powder and large impurities. The finished powder and large particles are discharged into collections. Fine powder goes on packaging. Large impurities are added to the crushed oil cake and fed to the second grinding. In order to prevent the cocoa powder from heating up during grinding on the disintegrator, air is sucked through the disintegrator using a fan. The air then passes through a bag filter where it is cleaned from small particles of cocoa powder. Filter sleeves are automatically shaken to remove cocoa powder.
The resulting cocoa powder according to GOST must have a residue on silk screen No. 38 and on metal sieve No. 016 no more than 1,5%.
These settings have a drawback: when sifting cocoa powder, the sieves are periodically clogged, especially during the warmer months, which causes the equipment to stop; in addition, at the slightest damage to the sieve, large particles will fall into the powder, causing its quality to deteriorate. Due to insufficient cooling of the powder leaving the disintegrator, the cocoa butter melts and forms large crystals, as a result of which the cocoa powder acquires a grayish tint. In addition, these installations take up a lot of space. At present, installations are being forced out by aggregates with air separators, where cocoa powder is divided in size in a stream of air.
In fig. 39 presented the unit of the Swiss company "Schenenberger." The unit works as follows. Cocoa cake, cooled to a temperature of 30 — 35 ° C, is fed to a crumbler with a gear shaft, crushed into pieces the size of a walnut, and then loaded into an electric dispenser, passes a magnetic apparatus and passes through a lock gate into a high-speed disk-pin mill 7, into which cooling air with a temperature of 8 — 10 ° C is supplied. Pieces of the cake supplied to the mill are crushed by blows
rotor pins, rotating at high speed, and c. the form of cocoa powder is thrown into the bottom of the mill. Caught up by the air jet generated by the 5 * fan. Cocoa powder particles pass through the 4 cooled tubes system and enter the 2 separator, where they are divided into two fractions. Fine grinding by air flow is carried to the 3 cyclone and discharged as ready-made cocoa powder through the bottom opening. The 5 fan returns air to the 1 mill, capturing large particles from the 2 separator for re-grinding.
Fig. 39. Grinding and sieving unit for cocoa powder with air separation.
Double-walled pipes of the unit are cooled with a solution of sodium chloride or sugar solution, from which the metal corrodes less. On condition of fine grinding of grated cocoa, the cocoa powder obtained on the unit has a high degree of grinding and a pleasant reddish tint.
The addition of vanillin as an aromatic substance according to the recipe is made in all installations in crushed oil cake before final grinding.
The finished cocoa powder has the following chemical composition (in%): moisture not more than 6; fat not less than 17 (for cocoa powder with low fat content not less than 14); fiber content not more than 5,5 for cocoa containing fat
no less than 17, and no more than 6 for cocoa with a fat content of at least 14; total ash content in cocoa powder, untreated with alkali, no more than alkali-treated bives no more than 9.
Cocoa powder with sugar in the form of powdered sugar and chocolate with milk powder, which is prepared from a mixture of cocoa powder, powdered sugar and powdered milk, are also produced.
Packaging and packaging of cocoa powder. Cocoa powder is packaged in cans and cardboard boxes weighing from 100 to 250.
Tin cans better protect cocoa powder from moisture absorption and extraneous odors during storage, but packaging is done on an imperfect machine, where cocoa powder is measured by volume in a parchment bag inserted into a can. All other operations - closing the bag, the lid and pasting the parcel post - are done manually.
The packaging and packaging of cocoa powder in cartons is done on machines that make the inner bag of parchment and the outer box of colorful cardboard blanks, put the cocoa powder in the bag, weigh the box of cocoa powder on the control scales and stick the box. The machine fills 60 packs per minute. Such machines are manufactured by the Voronezh Machine-Building Plant for boxes on 100 2.
The packaged cocoa powder is packed in corrugated cardboard boxes or plywood boxes.
Waste and waste in the production of chocolate and cocoa powder. Kakavella, resulting in the crushing and screening machine in the form of waste, is used in the manufacture of fat glaze.
Broken and glued beans, separated during sorting, are roasted separately and used to make medium grades of chocolate.
A large cocoa powder, obtained as a waste in sifting and separation plants, is used for sprinkling caramel and sweets, as well as making candy corps.
In the process of punching out chocolate, deformed chocolate is obtained from the forms, which is heated, filtered through mechanical filters and fed to the molding. Deformed chocolate with fillings is used for making fillings.
REFERENCES
- Confectionery technology. Edited by A. L. Sokolovsky. Food Industry Publishing, 1959.
- Collection of technological instructions for the production of caramel, candy, toffee, chocolate, cocoa powder, marmalade-pastilla, dragee and halvah. Food Industry Publishing, 1960.
- Handbook of pastry chefs. Part I. Raw materials and confectionery technology. Food Industry Publishing, 1958.
- Handbook of pastry chefs. Part II. Technological equipment of confectionery production. Food Industry Publishing, 1960.
- Serebryakov MN Manufacture of chocolate products. Abroad. Tsintipischeprom, 1960.
- Recipes for chocolate, cocoa powder and chocolate products. Food Industry Publishing, 1952.
- Sokolov L. A., Ptushkin A. T., Kuznetsova L. S. and Stepanovich 3. 3. The impact of roasting cocoa beans on the specific energy consumption required for their subsequent grinding. Bakery and Confectionery Industry, 1960, No. 2.
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