In modern machines enrobing constant level is maintained regardless of the number of tempering the chocolate flowing through the machine. An example is the installation Sollich Temperstatic TSN with grid widths of up to 62 120 354,2 cm and a capacity of kg / h (model «62») and 708,41540 kg / h for the model «130».
Built-tempering chocolate is described below (scheme passage chocolate enrobing machines, see. Fig. 7.22 and 7.23).
Tempering. Chocolate supplied from the main tank into the storage tank and the heating cylinder, heated to a temperature where 40 ° C and gets rid of crystals of cocoa butter. He then falls into a tempering cylinder (1 stage), where it is cooled to 28 ° C (milk chocolate) or 29 ° C (pure chocolate). Accurate control of the temperature in the cooling surface, combined with vigorous stirring provides complete crystallization of cocoa butter. Then the chocolate enters the cooling step 2, where temperature 1 ° C higher than 1 stage.
After cooling 2-th stage is supplied to pump chocolate enrobing or immersion tray. Pump capacity specially chosen just large
Рис. 7.22. Глазировочная машина Теmperstatiс® (фирма SOLLICH GmbH., Г. Бад Запьцуфлен, ФРГ)
Fig. 7.23. Flow of chocolate (firm Sollich GmbH., Bad Zaptsuflen, Germany)
necks than to pass 1 stage, as additional chocolate is fed from the tank for tempering (between the 1 and 2-th-th stage). The latter serves as a drive, which chocolate temperature is kept slightly higher than the end of the cooling step 1. The residence time of the chocolate in the tank is set in advance and is not regulated by the operator (this is where the remaining melt unstable crystals of cocoa butter).
Since the chocolate enters the tempering tank continuously, there is always a certain excess chocolate is formed, which flows into a heating tank or included in chocolate, coming from the enrobing machine. The ratio of these shares does not affect the residence time in a tank of chocolate tempering. Temperature control is performed by using a special water circulation system.
Some problems arising during glazing
Despite the fact that we have already dealt with various problems glazing, we found some of them the opportunity to stay in more detail.
Tempering. Chocolate must be properly tempered. Insufficiently tempered chocolate resulting in poor crystallization in a cooling tunnel, the chocolate from sticking to the conveyor belt, and affects the color gives the fatty plaque.
Toppings (shell) products. Chocolate confectionery is coated with a variety of products which are manually or mechanically loaded onto a conveyor belt, and then placed on a grate enrobing machine and passed through a curtain of chocolate.
For cold fillings (casings), there is one common problem. If they were produced separately, then they (especially milk candies) could be stored in the refrigerating chamber for some time to stabilize the form. Such products must be preheated before glazing, otherwise, due to the pre-cooling of chocolate, the glazed items will look bleak and have a grayish shade. Usually pallets with candy corps before glazing in advance are brought to the glaze shop for warm-up, but in this case there is another problem - if the room temperature is below the dew point, condensation is formed. In the worst case, this causes an increase in the viscosity of excess chocolate, which drips from the veil and causes plaque formation. The temperature of the hulls and the room for glazing should be maintained at the level of 24-27 ° C, since too warm bodies inhibit the cooling process and promote spreading of the chocolate, which forms "tails" at the bottom of the products and makes it difficult to control their mass.
When the body is mechanically prepared (eg by extrusion), the workpieces are fed directly into the coating machine from the extruder. For their heating, an apparatus for heating by radiation located above the conveyor is used. Preparations prepared using starch should be thoroughly cleaned from it or blown with an air jet. If this is not done, the chocolate will cover the preform unevenly and numerous "microchannels" are formed. In the glaze room, there should be no drafts which, in addition to the unwanted color, can lead to crystallization of the chocolate on the grating of the coating machine.
Fatty workpiece (fudge, marzipan, hazelnut paste) to cause the formation of dark chocolate during its shelf life of fat bloom. This can be prevented by adding to the chocolate coating 2-4% anhydrous milk fat.
Shrinkage during cooling. The shrinkage during cooling and the seriousness of its consequences is often underestimated. Chapter 3 we examined in detail the cocoa butter and its ability to shrink when cooled. The degree and rate of shrinkage associated with cooling operation. If coated preform to cool too quickly or unevenly, it may cause a number of problems.
Violation form. Fig. 7.24 shown quench impacts the upper surface glazed tile, while the lower surface remains soft.
Seepage, detachment. Fig. 7.25 and 7.26 shows effects of exposure to strain under the pressure of compression coating, resulting in the filling seeping through pinholes or glaze defects. In some instances, the coating can crack and peel off completely filling.
Such detachment and leakage in the worst case is used as a filling or a sugar fudge. Cracking and peeling are more common in mild porous fillings (eg from wafers). Violation form compounded when top chocolate coating thicker bottom. Leakage is often mistakenly associated with fermentation.
Relative humidity of air in cooling tunnels and on packing sites. Unfortunately, in the construction of cooling tunnels, the problem of air humidity is not paid enough attention. The most obvious problem is condensation of moisture on chocolate products when they are delivered to the packaging site after the cooling tunnel of the coating machine. Previously, many enterprises did not have good air-conditioning packaging areas and poorly designed low-temperature coolers were used, from which products arrived at temperatures below 13 ° C. In the summer, the dew point was often higher than this temperature, as a result of which production had to be stopped. In recent years, air conditioning has become more widely used since it has become economically uneconomical to stop production.
Fig. 7.24. Violation form
Fig. 7.25. seepage
Fig. 7.26. detachment
Another problem (less obvious) is associated with high air humidity in the cooling tunnel itself. In some designs of air cooling tunnels for chocolate with a cooling air temperature, for example, 13 ° C, there are no means for controlling the relative humidity of the air entering the cooler. In the cooling system, atmospheric air is injected, and for reasons of economy it is simply cooled down to the minimum required temperature. The relative humidity inside the cooler depends entirely on the dew point of the air being pumped, reaching 80-90% in some cases. As chocolate absorbs moisture from the air (dark - at relative humidity from 85% and above, milk - from 75% and above), the moisture content in chocolate increases and conditions for the formation of sugar deposits are created.
The next problem is a high level of humidity during thaw cooling of cooling coils or in the event of malfunctions in the cooling system. The consequences can be very serious, since air with relative humidity of about 100% can get into the cooling tunnels, which, in addition to spoiling the chocolate, can lead to the formation of mold on the remains of chocolate in the cooler and on its surfaces. Spores of mold can get on other products, in coolers can appear an unpleasant smell. In order to avoid such problems in any cooling system, the incoming air should be drained by lowering its temperature to values lower than those used during operation. At an operating temperature of 13-14,5 ° C, the air entering the cooling tunnel must be passed through the cooling coils and brought to a temperature of 7 ° C and then heated to 13-15 ° C so that the relative humidity of this air is 63-70% ( The dew point is 7 ° C). With such a relative humidity, damage to the chocolate or coolant will not occur. There are two ways to increase the air temperature from 7 ° C: passing it through the heating coils and mixing with the injected air. The first method is more reliable and recommended for the operation of cooling tunnels of coating machines.
In the confectionery industry a variety of technologies are applied, many cooling systems have been enhanced - so applied before the brine circulation system was replaced with a more compact section freon which may be used when needed for topical (local) cooling.
Pelleting - this is a special process of sequential application of layers of chocolate or sugar with the use of rotating surfaces (for Uoo technology or stencil method). Sugar panning seen in different sections of this book, and below we consider only the chocolate panning.
Chocolate is often drazhiruyut nuts (almonds, hazelnuts and peanuts, as a rule, first fried, and Brazil nuts - no). As the filling is also used raisins, balls of condensed milk, canned ginger or cherries, various pastas and nougat. The filling should be relatively hard, or it may be spread on the sheet.
pelleting technology usually consists of three separate operations:
- Preliminary enrobing fillings;
- applying a chocolate layer (or sugar in sugar panning);
- final glazing products for giving shine and protection against abrasion and moisture.
Drapering devices (Fig. 7.27) are made of copper or stainless steel especially for various purposes: sugar coating, chocolate coating or for simple glazing. They can be equipped with devices for emptying and changing speed. Such drapery devices are also equipped with air ducts, through which products blow air during their rotation. The temperature and humidity of air is important to maintain within specified narrow limits. Chilling the applied chocolate requires cold, dry air, and for warming the syrup requires warmer air. Initially, syrup and chocolate were applied manually, however in modern large installations guns are used (adjusted to separate sheets with the possibility of adjusting the direction of the jet when the device rotates). The feed is carried out through a pipeline from the tanks, and all drageeing devices can be controlled by one operator.
Below is an example of panning of nuts.
Fig. 7.27. A device for pelleting by Volvo Technology (firm Norman BartleetLtd., London)
Pre-glazing carried out for the primary coating the surface with a thin layer of chocolate walnut, which prevents the penetration of the chocolate peanut butter and the subsequent formation of fatty plaque, or softening of the chocolate. When applying thick coatings chocolate may be dispensed with this step.
For the frosting nuts device rotates and pour it in small portions syrup 50% concentration. Rotation device provides an even distribution of syrup on the surface of kernels, and the air stream before it dries icing condition. The subsequent addition of syrup increases the thickness of the glaze, but before each addition of syrup each layer must be dried.
Panning for such formulations have different, but for best results a viscous syrup to be crystallized and dried in contact with the layer. To increase the viscosity of gum arabic is added to the mixture or equivalent replacement, and for preventing crystallization - glucose syrup. Proportion of the two selected by experimentation depending on the type of filling.
Some confectioners building up layers of glaze mixture of cocoa and powdered sugar. This method is particularly effective in canned fruits or dragee ginger, as it allows to neutralize the preservative stickiness syrup which was dried by blowing air at 21-24 ° C and a relative humidity 50%.
Applying a layer of chocolate. To do this, use dark or milk chocolate, which to cover the entire surface of the product should be sufficiently liquid. With a manual method of coating, it is better to use tempered chocolate, which makes it possible to ensure its rapid crystallization, to prevent the formation of adhesive layers and the discoloration of products. When pelletizing with a sprayer, the best results are achieved by using unmetered chocolate (if its temperature is reduced to 34-35 ° C). The mechanical spraying process promotes the formation of crystals and the solidification of chocolate.
Since the final gloss is given to have sugar-coated products, a slight discoloration of the chocolate at this stage is considered to be acceptable.
A chocolate layer is applied uniformly, and its curing temperature is influenced by the cold air flow around 13 ° C 60% relative humidity and lower. When panning should avoid clumping products, which largely depends on the skill of the operator in applying the chocolate.
The final glazing. There are various methods to achieve the final gloss. Best results are obtained by coating two distinct layers - syrup and shellac.
product preferably before enrobing chocolate covered otsadit available on pallets, which will allow to form a rigid texture; if the glazing is performed immediately after the chocolate coating, product shape may be impaired.
"Syrup" glaze similar to that used in the preliminary stage of glazing (you can also use food dextrin), and instead of Gunma
rabika possible to use gum crystals. Ingredients Formulation Number and the concentration of syrup is adjusted depending on the type of product glaziruemyh (enrobing this purpose - to provide products with a smooth surface that will not crack, peel or crystallizes and can serve as a basis for the final enrobing).
"Syrup" glaze obtained by pouring syrup on a rotating mass of nuts. In an apparatus for quickly panning syrup coats the surface drazhirovan- GOVERNMENTAL chocolate products. Spraying is not necessary, and therefore the entire portion Formulation syrup can be added to two or three stages with intermediate drying.
For drying use again blowing air stream with a temperature of 18 (milk chocolate) to 21 ° C (dark chocolate) and a relative humidity of 50%. Drying is continued until a cease-sticking.
At the end of this stage of glazing, it is desirable to keep the chocolate on sheets at least 12 h at a temperature of about 18 ° C and relative humidity of 50-60%. As a result, the glaze stabilizes and a film with the same moisture distribution over the entire area is formed. After this drying, a glossy wax coating is applied - if applied in a rotating device, then it is covered from the inside with a wax layer. Usually bees or carnuba waxes are used (the latter gives a harder glaze), although there are also formulations with acetylated glycerides. Any wax gives a relatively matte surface, and to give gloss, shellac glazes should be used.
It is preferable to use shellac with the content of natural wax, since it gives a more elastic film and is distributed evenly. The resin is dissolved in ethyl or isopropyl alcohol, obtaining a thick opaque (because of the presence of wax) solution, however, the glaze turns out to be fairly transparent. The concentration of the solution depends on the type of products to be glazed, but is usually 25-30%. Suitable shellac glazes are commercially available, and they are applied, as a rule, in rotating draperies. This technology requires certain skills, because due to the rotation of the device, the glaze should be applied in an amount that is barely sufficient to completely cover each product. Immediately after this, the rotation stops and the solvent must evaporate. At this point, the device should not rotate, otherwise the glaze will peel off. Evaporation of the solvent can be accelerated by blowing the device with air. Such solvents are explosive, and therefore in accordance with regulatory enactments of some countries, this operation should be carried out in a separate room by remote control. When the glaze dries, the device is rotated two or three times to separate the products from each other, after which they are discharged onto the sheets for final drying and hardening.
Firm Zinsser (USA) offers a number of shellac confectionery coatings, including a low content of beeswax and acetylated monoglycerides. Their addition to reduce the stickiness of products in rotation drazherovalnogo device. German firm Kaul GmbH produces a variety of water-soluble alcohol and glazes called «Capol». They are suited for panning a chocolate and sugar.
Shellac glaze except gloss products offer good protection against moisture action, making them panned chocolate products are very popular in countries with hot and humid climate.
In addition to products, sugar-coated chocolate, it is now very popular chocolate products, topped with icing. Sugar frosting enrobing similar to sugar syrup, but it leads thicker layers, forming a kind of sugar coated. Read more about this technology, see. Previous article.
Considerable interest in the confectionery industry has caused the use as a protective coating zein. Zein - a corn protein, the addition of which to food is not limited to any regulations. Zein is soluble in ethyl alcohol and isopropanol in proportions (5-20% wt.). The zein solutions are also used plasticizers - glycerin and propylene glycol.
It is believed that the glaze can be applied zein in rotating the rotary shaft drazhiro- devices. They are also widely used in the production of compressed tablets. Their description can be found in branded materials Freeman Industries Inc. (USA) Benzian AG (Switzerland).
A list of major manufacturers and their research units
Aasted International Bymarken, Denmark - tempering, molding.
Baker Perkins, Peterborough, UK.
Norman Bartleet Ltd., London, United Kingdom - pelleting.
Bindler GmbH, of Bergneustadt, Germany - Installations for the manufacture of confectionery packages.
Coilman GmbH, Lübeck, Germany - machines for manufacturing hollow articles.
Freeman Industries Inc., of Takahoe, NY, USA - zein glaze.
Kaul GmbH, Mr. Elmsgorn, Germany - conventional glaze.
Lloveras S. A., of Terrassa, Spain - Chocolate "noodles."
Richardson Researches, of Hayward, California, USA.
Sollich GmbH, Bad Salzuflen, Germany - enrobing machines, cooling tunnels, temperometry.
Westal Company (Baker Perkins), of Redditch, United Kingdom - installations for the production of confectionery packages.
Zinsser and Co., Somerset, New Jersey, USA - shellac glaze.