In all chocolate products (both molded and for decoration), the fat content gradually and steadily decreased. With a high content of cocoa butter, the chocolate significantly "seated itself", and this simplified the extraction of products from molds. With a reduced fat content, which is achieved by the addition of emulsifiers and the use of additional viscosity-reducing mechanical devices, such "shrinkage" is no longer observed. At present, high-quality, fine-grained chocolate with a total fat content of less than 28% is produced and molded. Less quality chocolate with a coarser structure can contain up to 25% fat. Reducing the fat content to less than 30% especially affects the quality of milk chocolate, the structure of which becomes soft and less brittle.
The procedure for extracting milk chocolate products from deep forms is complicated with a relatively high proportion of milk solids (25%, including milk fat). Reducing their number to 15% significantly facilitates this process. If manufacturers do not have to refer to a product with an indication of its frosting with chocolate from whole milk, COM or dry whey may be used as ingredients.
The addition of recycled raw materials leads to problems with the removal of articles from molds due to the presence of soft fats in processed fillings, and it is better not to use such chocolate for making chocolate casings. Added to dark chocolate milk fat (to protect against plaque formation) leads to some difficulties, if its content is maximum (4%). Molded surfaces are much less prone to formation of plaque than in glazed chocolate - the introduction of special additives is required only to protect against the plaque of the top of the products, and in a minimum volume (up to 2%).
Many chocolate bars and tiles include whole or chopped nuts (hazelnuts, almonds, Brazil nuts), and some products include raisins that must be dry and firm (otherwise the raisins can "stick together", which will lead to "traffic jams In the hopper hopper). Raisins, purchased in large cardboard boxes, are somewhat compressed, and usually it is sprinkled with sugar or cornstarch for separation.
Popular ingredients for chocolate products are air rice and other cereals, as well as various sugar fillings. To avoid the sensation of granularity during chewing, their structure is made porous.
Some such ingredients, especially cookies, have the ability to absorb cocoa butter contained in chocolate, and to avoid adding cocoa butter, it is advisable to use accelerated mixing and casing. To continuously supply ingredients to the flow of tempered chocolate, special devices have been developed. The ingredients are mixed according to the formulation and fed directly to the hopper for depositing.
Among the molded products, waffle tiles, usually consisting of chocolate-lined waffles with flavored cream filling, are very popular. In the production of this type of products, quite complex equipment is used, the task of which is to fill the multi-sectional shape with chocolate and push into each section wafer strips. Excess chocolate is removed with a roller or scraper.
Shaping and refrigeration systems for buildings
Producers quite often have problems with cooling chocolate in forms and cases of confectionery products, as they are different from those used in coating machines. In this connection, several points should be highlighted.
Chocolate tablets (pastilles)
When molding tablets, tiles and casings for good emptying of molds, a good shrinkage of chocolate is required, which requires good tempering and fast cooling. The latter is best done by blowing a strong jet of air, and not by exposure to low temperatures (preventing the formation of unstable crystals of cocoa butter). When glazed, rapid shrinkage is undesirable, as it leads to cracking of the chocolate coating and possible drying of the product due to cracks in the coating.
After depositing the chocolate and chocolate form reversal should be cooled without destroying it, and so they try to guide the cooling air flow is not directly on the chocolate.
The slim body cools down quickly even under the influence of moderate blowing - too intense and uneven cooling can lead to structural breakdown. This effect is especially evident in the manufacture of cases for tiles with fillings and chocolate bars - as a result of the structural damage of the body freely move in shape and break at the edges that can bend upwards. In this case (for example, if the filling is a hot fudge), the body of the article can soften and settle again in the mold, which will cause the pockets of its depressions. Subsequently, when the top of the articles is deposited and cooled, shrinkage occurs, further aggravating the disturbances in the shape and structure of the articles. Curved tiles create problems when packing, even until it breaks.
"The right methods of production"
The correct production methods (PPMs) or Good Manufacturiing Practice (GMP) - a concept recently is widely used in foreign literature to describe the technological process. Implementation of the requirements necessary for PMP Certification predpriyatiyapo ISO9000
The productivity of all types of molding plants depends on 100% unloading of products, since in the case of "blockage" of molds, they should be removed from the technological cycle. The chocolate adhered to the mold is removed manually and the mold is cleaned. In the case of equipment for the production of cases of confectionery and stuffed products, this is quite expensive, and additional problems are created by waste forms cleaning.
The quality unloading of products from molds depends on the proper tempering of the chocolate, sufficient and uniform cooling, as well as the cleanliness of the molds at the beginning of molding. Proper tempering contributes to good shrinkage, but milk chocolate because of the content of soft milk fat in it is more difficult to extract from molds than dark chocolate. This is especially true of chocolate for making small cases, for which it is better to use chocolate with a low content of milk or milk fat.
Cleaning forms should be carried out periodically, and for this purpose special washing equipment is used. The cleaning process includes a pressure washer under pressure by hot water with a detergent solution, rinsing (preferably with soft water) and then drying with a stream of hot air. Before cleaning plastic molds, it is recommended to obtain information about the desired detergents from the manufacturer of the forms.
In the production of assorted, confectionery tiles covered with chocolate, chocolate biscuits and cakes use chocolate glazing. We have already mentioned the manual glazing, but this method is used mainly for expensive confectionery products, sold mainly in branded stores.
Principles of enrobing machines can be described as follows.
The products to be glazed are placed on a conveyor belt (usually tarpaulin with plastic coating). Small products are laid, as a rule, by hand, and large ones by mechanical devices, especially if the glazing process is preceded by cutting or extrusion. From the conveyor belt products are transferred to the glazing grid, which first passes through the bottom glazing device. This device consists of a system of pumps or rollers forming a small layer of tempered chocolate on the grate. Products are raised and undergo glazing from below; with a glazed bottom surface they automatically go to another tape, pass through the cooling table and from there - onto the main grille.
Products with a glazed bottom are transferred to this grate through a curtain of tempered chocolate, resulting in the glazing of the top and sides, and a thin layer of chocolate is applied from the bottom. After glazing, the products are blown with air (fans), and the grate is shaken (both are adjusted depending on the type of products, controlling the amount of chocolate applied). From this grid, the chocolate products are transferred again to the belt of the conveyor, which carries them to the cooling device, but before that, the products pass through the "tails" cutoff mechanism, which is a small diameter rotating roll that removes the flow of chocolate from the edges and edges of the products.
Such a "shut-off" mechanism is also necessary at the unloading area of the lower surface glazing device, otherwise the formed "tails" will partially harden upon cooling, and when passing through the glazing device "grow".
Many coating machines do not have separate glazing devices on the lower surfaces. In the production of small items, this may not be important, but for large ones it is a significant drawback. In the coating machine, the supply layer of chocolate for the top provides some coating to the lower surface. For large and heavy products shaking the grid can lead to the fact that under the influence of gravity they will "sag" through the chocolate, and the lowering of the bottom will be very thin. Thus, the filling of the product is not sufficiently protected and can dry out or absorb moisture (depending on the type of filling and environmental conditions).
The installation scheme for glazing is shown in Fig. 7.15; in the last 50 years they have been significantly improved - from small installations that require constant attention of specialists and appropriate regulation, they have turned into quite large aggregates with automatic tempering of chocolate.
Fig. 7.15. Installation for glazing
a. Conveyor (non glazed enclosure)
B. Apparatus for glazing the bottom surface
from. Conveyor for cooling the bottom surface
d. Глазировальная решетка
e. Capacity with tempered chocolate (with a capacity ottemperirovannoy chocolate mass)
f. Ottemperirovannaya chocolate mass is fed from g
a. glazed products
m. cooling device
Manual or mechanical finishing (decoration, drawing of patterns already on the glazed chocolate products) can be made on stage k.
The first units were wide-40 45 cm, and the current can be wider than 135 see and process huge quantities of chocolate.
At large coating plants without automatic control, a constant supply of tempered chocolate is necessary. For this purpose, thermoregulation containers are usually used, from where the mass enters the charging hopper of the glazing machine. An experienced operator must supervise the supply of chocolate to the hopper, which monitors the degree of tempering, the thickness and viscosity of the chocolate mass, regulating the circulation of cold and hot water. In addition, he controls the filling of containers with tempered chocolate. If the container is filled, it can be added chilled, non-tempered chocolate, and tempering will take place in the container itself.
Implementing the latter principle, in some enterprises, the drip tank of the coating machine is used with unmetered chocolate, depending on the need for chocolate. From the foregoing, it is evident that certain skills are required to ensure efficient operation of the coating machine, respect for a given thickness of the chocolate layer, and degree of tempering.
In modern high-performance automatic units, the tempering process is automated. This is a complicated procedure, since the process of glazing differs from molding in that a portion of the tempered chocolate after use in the curtain is returned to the reservoir of the coating machine, increasing the viscosity of the chocolate contained therein due to the formation of new cocoa butter crystals. Consequently, they must be melted again either by returning to the intermediate storage tank, or by mixing with the un-tempered chocolate. Automatic glazing systems are discussed below.
Mechanical devices for glazing
Regardless of whether the enrobing machine automatic or manually operated, should be aware of some of it occurring in the mechanical processes.
Loading. At this preparatory stage, the products are unified in the coating machine (or in the lower part glazing unit).
Products are placed in bulk in the channels of their distribution along the width of the belt (vibro-mode). Then their "strips" come from the conveyor belt to the cradle or chain conveyor of the coating machine, which moves faster, distributing the products in the longitudinal direction, so that they do not stick together during the glazing. When transferring cases from one conveyor to another, a gap is provided for cutting off the "tails" (a special cut-off device is used for this purpose).
Pre-glazing of the bottom surface and tables for cooling. As mentioned above, preliminary glazing of the lower surface is necessary when glazing large products. These devices should be separate mechanical units, and, as a rule, they are not loaded with tempered chocolate from the coating machine (except for the first batch).
thermoregulation system shall be equipped with temperature control devices.
After covering the bottom surface of the products, they pass through the "tail" trimming device to the cooling table, where the chocolate partially solidifies. This allows him not to melt on the grid of the coating machine.
To prevent condensation of moisture, the cooling table must be equipped with a temperature control system, and the conveyor belt feeding the bottom-glazed products should be as close to it as possible (sometimes a slight bend of the upper surface of the conveyor is used for this). Usually, to harden the chocolate on the bottom surface of the product is enough 2 min stay on the cooling table.
In the case of the formation of condensate on the cooling table (due to the high humidity in the glazing area), use a kind of cooling tunnel (closing the cooling table with a casing).
Section glazirovaniya. This part of the enrobing machine consists of the following elements:
- A tank from which tempered chocolate is served for glazing, with a kneading organ rotating at a low speed.
- Pump and agitator, supplying chocolate upwards for glazing of the cases and the lower part of the products. Here, a heating jacket is needed, and the tank should be below the discharge level (air or chocolate), since air bubbles in the chocolate mass layer should be avoided. The position of the grating is adjusted so that the nozzles of the chocolate layer are as close as possible to the top of the glazed articles.
- The fan, by means of which the thickness of the coating is regulated (adjustment is made according to the angle of inclination and height). The temperature of the blowing air should be monitored, since overheating leads to partial chocolate de-tempering (the optimal temperature is 28-29,5 ° C, but we should not forget about the air speed).
- Vibrator. After glazing, the products are "shaken" (mechanically or electrically subjected to vibration). It is desirable to be able to separately adjust the amplitude and frequency of vibration, but this is not possible in all coating machines. Unevenness on the surface of the chocolate is eliminated by vibration or blowing, but if the chocolate freezes faster, these operations may prove ineffective.
- Continued chain conveyor serves as the finishing table (sometimes heated to remove the excess of chocolate and its return to the reservoir).
- Device for removing "tails" (edema). It is important to monitor its correct setting - if its position is too high, the chocolate from the lower surface of the products will be knocked together with swelling.