DE3803180A1 - Process for the heat treatment of seed material forming at least some volatile aroma substances on heating - Google Patents

Abstract

A process for the heat treatment of seed material, such as cocoa and/or cocoa products, containing constituents forming at least some volatile aroma substances on heating, is carried out in such a way that isolated aroma substance is fed during the treatment, in particular at the end. This is preferably carried out in such a manner that the vapours forming during the heating are taken off; the aroma substances, in particular pyrazine, contained in the vapours taken off are recovered and added back to the seed material. <IMAGE>

Description

The invention relates to a method for the heat treatment of when heated at least partially volatile aroma substances Core goods, such as cocoa and / or cocoa products, according to the Oberbe handle of claim 1. In addition, the invention relates to a device for grinding core material, such as cocoa and / or Cocoa products, with a pre-mill.

When roasting fruits, especially cocoa, takes place under external heat supply the so-called "Maillard reaction", which is a lot number of chemical processes. From this develop as End product various, partly volatile flavorings, of which one important and typical representative that pyrazine is. Pyrazine will get that part of the protein under the influence of heat building blocks (amino acids) with the naturally existing sugars react. The stoichiometric ratio is generally mean that after converting the total amount of sugars only about 20% of the amino acids are converted to pyrazine. additional Roasting would now bring no valuable aroma substances.

But if you want a clearer roasted taste, you go like that before that reducing sugars are fed to the reaction keep going when heat is on. This is also in the With regard to the volatility of the flavoring substances it is usually necessary. Typically, reducing sugars are added in one Thin film evaporator, such as in the DE-OS 27 43 246 or EP-PS 32 217 is proposed. Thin film evaporators have their name from the fact that they are too treatment mass left in a thin layer over its surfaces is, whereby gaseous substances escape. This gaseous Fabrics are drawn off as vapors and contain unwanted ones  Flavors, such as acids or stink substances. But now there too the flavors are volatile, it is practically inevitable that also a large part of the valuable aroma substances in this Treatment is lost. Therefore, the flavorings must be in excess shot by adding sugar.

The invention has for its object a larger We Degree of efficiency in the treatment of cocoa and cocoa products (Chocolate, etc.). In particular, the effort is supposed to Roasting energy is reduced and the taste is better under Be brought under control.

For this purpose it is provided according to the invention that at least an aroma, in particular pyrazine, in one treatment step is added or injected. This flavoring could in itself synthetically produced or otherwise obtained.

However, the method according to the invention is preferably carried out in this way leads to the fact that the flavorings contained in the withdrawn vapors especially the pyrazine, recovered and the core good during, however preferred at the end and especially after the heat treatment be mixed again.

This is preferably done in such a way that the vapor withdrawn selective binder for flavorings contained in the broth, esp special roasted aroma, such as pyrazine, supplied in such an amount and is mixed with the partially condensed vapor that the Flavorings are largely completely bound by the binder.

In particular, it should be provided according to the invention that the binder as an essential component at least a vegetative Contains fat such as cocoa butter, peanut fat, coconut fat etc.

By binding the flavoring substances, in particular to a fatty substance, it is possible to separate acids and stink substances, the aroma  substances, on the other hand, to be recovered and later re-injected to use in the more or less already treated core material.

It is also useful if there are any remaining when mixing gaseous components, preferably during the mixing process, subtracted from.

To separate the bound aroma substances as optimally as possible can, there is another embodiment through that then the mixture of binder thus obtained and condensed vapor portion a neutralizing liquid, such as milk of lime, is added in such an amount that the Acids contained in the mixture at least essentially new be realized.

The flavors can largely be completely recovered that by the bin containing essentially the flavorings by gravity or centrifugal force separation from by Neutralize the acids obtained aqueous salt solution abge is separated.

If the method according to the invention pre-grinding the core Good, especially under vacuum, is according to the invention preferably provided that the vapors from the pre-grinding stage deducted and / or the separated containing the flavorings Binder of the pre-grinding stage is fed.

Another inventive idea that can also be used independently is that the pre-grinding stage is a liquid reaction medium um, in particular a sugar solution, is supplied. Here should it may preferably be provided that the one containing the flavorings separated binder is added to the sugar solution.

If a thin layer ver attenuation level is provided, another is characterized advantageous embodiment in that vapor from the thin  deducted layer evaporation stage and / or the flavorings containing separated binder of the thin film evaporation stage is fed.

If a conching stage is provided, the invention provides in part further that the aroma containing, abge separated binder is fed to the conching stage.

A preferred device for carrying out the inventive Process, which is also independent of the inventive The method is applicable, is designed so that in the grinding chamber a reaction medium supply line opens. This reaction medium Supply line is preferably one liquid line, the others ends, preferably via a pump, from a storage container going out.

It is particularly advantageous if the reaction medium supply Line opens near the core feed, because then the core comes into contact with the reaction medium right from the start.

If a vacuum connection is provided on the pre-mill, should this at one of the mouth of the reaction medium supply line remote location.

The pre-mill expediently consists of at least two successive grinding stages, each with a rotor and a stator, and precisely then is the requirement of spatial separation of supply line mouth and vacuum connection particularly easy meet, especially if the first grinding stage and the mouth the vacuum connection is assigned to the following grinding stage.

According to a preferred embodiment, those with flavoring mixed vapors first in a thin film evaporator won, but in a vacuum mill. Such a mill is for example, have been proposed in EP-PS 18 607. Yourself  Any such vacuum treatment is understandable Mill can be used, for example a knife mill.

It is advisable to only make the volatile flavorings possible to be injected as late as possible because otherwise some of it is lost in the course of treatment. Because preferably injecting in a finishing treatment In the case of cocoa, this is expediently carried out in the Conche happen.

The addition of treatment agents is in other cases especially beneficial in a pre-mill because of this treatment substances then have time to treat themselves with the part of the treated goods, such as cocoa, more intimately. Here This advantage arises regardless of whether aroma substances are added or other additives. That's why it is advantageous if a pre-mill, for example according to the he mentioned EP-PS 18 607 is provided with an injection opening. This injection port can, but need not, be nozzle-shaped.

As will be explained later with reference to FIG. 2, it is advantageous to arrange the injection opening near the inlet for the regrind so that the regrind comes into contact with the respective treatment substance from the start. An example of such a treatment substance can also be simply injected fat, which on the one hand binds flavoring substances. In the production of chocolate in particular, it is often essential to add a certain amount of fat, for example cocoa butter or peanut fat.

Especially when such a pre-mill for a method of raising the content of flavorings is used, as described above ben, the one bound or in particular bound in fat recovered flavoring also added to this mill who , but it has already been mentioned above that the Zu administration is advisable at a later date. It But such a pre-mill can be increased in another way  Use the aroma content. For this purpose namely, preferably reducing sugar, such as dextrose or glucose into the pre-mill through the injection port brings and thereby exploited the effect that under the regrind heat is applied to the action of the grinding energy, which then causes the Maillard reaction mentioned. If so the pre-mill is designed according to EP-PS 18 607, so can acids and flavorings directly over the vacuum line tion are subtracted, the aroma substances through the selek tive binders (fat) are collected.

Fig. 1 shows a system for carrying out the method according to the invention in a schematic representation and

Fig. 2 is a cross section through a pre-mill formed according to the invention.

As shown in FIG. 1 are continuously fed cocoa beans or cocoa bean curd (Nibs) after peeling in a hopper 1 a preliminary mill. 2 The previous peeling is expediently carried out in accordance with EP-PS 68 221 or the fruits are introduced into the pre-mill 2 after peeling in a still warm condition after peeling. This roughing mill 2 is designed in accordance with EP-PS 18 607, ie it has a vacuum connection 3 . As can be seen from the representation of EP-PS 18 607, the pre-mill 2 can take different forms, for example the supply 4 located between the hopper 1 and the actual mill can be configured differently; the pre-mill 2 does not necessarily have to be of two stages, although this is preferred. Below the pre-mill 2 , a mixing and homogenizing device 5 is provided, from which the cocoa mass is placed on a conveyor belt 6 , which can preferably also be set by a pump, into which the cocoa mass is input.

The conveyor belt 6 or the pump brings the cocoa mass in the usual way to further treatment facilities, such as rolling mills or other mills, mixers for adding sugar and / or milk powder, etc. This route is only indicated by a broken line in FIG. 1 and ultimately leads to a thin-film evaporator 7 . This thin-film evaporator 7 can also be interposed between two grinding stages. As will be explained later, however, the thin-film evaporator 7 may be omitted entirely, whereupon the chocolate is refined on a conche 8 in the last stage. This conche is preferably designed in accordance with DE-OS 36 03 155 and / or DE-OS 36 26 732.

The vacuum line 3 is used to withdraw the vapors and acids containing ent from the grinding chamber of the pre-mill 2 ent. Likewise, from the thin-film evaporator 7, the vapors which are formed are removed via a line 9 . As shown, the lines 3 and 9 can be combined, so that the vapors are subsequently subjected to the same treatment.

A water ring pump 11 is connected to the line section 10 connected to the connection 3 and, if necessary, the connection to the line 9 . In addition, the line section 10 with the aid of a metering pump 12 from a container 13 a predetermined amount of a selective binder for flavorings contained in the vapors, in particular roasted aroma, such as pyrazine supplied. Such selective binders are primarily vegetative fats. In the treatment of cocoa in particular, such fats are usually necessary or beneficial anyway, in particular special cocoa butter or peanut fat. Other nut fats are also particularly useful, such as coconut fat, etc.

The mixture of substances thus conveyed via the water ring pump 11 is fed to a mixing container 14 . Another metering pump 15 delivers a neutralizing liquid, in particular lime milk, into this mixing container 14 from a storage container 16 . An agitator 17 ensures an intimate mixing of the substances in the mixing container 14 , the addition by the metering pumps 12 and 15 taking place essentially in stoichiometric amounts, so that on the one hand the acids contained in the container 14 are bound or neutralized, on the other hand by the the fats supplied to the container 13 , the flavorings contained in the vapors are completely bound.

The mixture is then transferred from the vessel 14 into a settling vessel 18 . The lighter fats rise to the surface in the settling vessel 18 and form a floating blanket 19 there . A probe 20 monitors the formation and expediently also the thickness of this floating blanket 19 and sets a pump motor M for driving a temporarily actuated pump 22 into operation by its signal via a control circuit 21 when the floating blanket 19 has reached a sufficient height. Via the pump 22 , the fat with the flavoring substances is then drawn off from the surface of the contents of the settling tank 18 and conveyed into a fat container 23 . In this fat container 23 the fats containing the roasted aroma substances and especially pyrazine from the storage container 13 are collected. The aqueous salt solution produced by neutralizing the acids, on the other hand, will accumulate below the floating cover 19 in the settling tank 18 and can then be discharged into a container via a lifting line 24 . In this way, the contents of the vapors fed via lines 3 , 9 and 10 together with the substances supplied from the storage containers 13 and 16 are divided into three fractions, namely a gaseous fraction which flows out of the water ring pump 11 in the direction of arrow 25 Liquid separator 26 is separated, the one by neutralizing the acids and the like. containing fraction 27 and the fraction contained in the container 23 , which contains the flavors that bind the binder.

The aroma substances contained in the container 23 , bound by a binder, in particular fat, can now be drawn off with the aid of a pump 28 and returned to the process. For this purpose, three options are indicated in Fig. 1, and it is in fact conceivable to install a valve 30 in the line 29 following the pump 28 for the optional supply of the flavoring agents to various points in the process. Of course, this is only an example, and the pump 28 , the line 29 and the valve 30 , as well as the connected lines can be replaced by any other means of transport. In particular, it is also conceivable to return the flavorings instead of optionally only at one point, to introduce them into the process at two or more points.

A first possibility is to ultimately return the aroma substances to the pre-mill 2 via a line 31 . How this is done most favorably will be discussed later with reference to FIG. 2. However, it has already been stated above that flavoring substances are expediently added at a late stage in the process, so that they no longer have the opportunity to escape.

As can be seen from Fig. 1, actually the line 31 does not open directly into the pre-mill 2 , as this could be the case, but into a mixing container 32 in which at least one sugar is dissolved and via a pump 33 , possibly a valve 34 and a line 35 is injected into the pre-mill 2 . A three-way valve 36 , which is expediently continuously adjustable, serves to regulate the supply quantity, whereas the excess of the liquid conveyed by the pump 33 is returned to the container 32 via a line 37 .

In this way, it is possible to largely recover the aroma substances generated by the grinding energy within the pre-mill 2 , which arises through the combination of sugar and amino acids (pyrazine).

As will be explained in particular in connection with FIG. 2, the mill specially designed for this process is also advantageous regardless of the production and separation of aroma substances. For example, fats or reactants can be supplied in this way at such an early stage, the latter from the very beginning and under the beneficial effect of an elevated temperature (especially if the pre-mill is used for a process according to DE-OS 34 06 570 will) act on the regrind and be able to react with it. This reduces the required amount of reagents or increases their effectiveness. In any case, however, it is necessary to connect the liquid line 35 to the pre-mill 2 to a liquid container 32 or 23 .

Another possibility of returning the aroma substances trapped in the container 23 is to feed them into the thin-film evaporator 7 via a line 38 , a rotary inlet 39 and a hollow shaft 40 . Equipped thin-film evaporators for this purpose have already been proposed in a wide variety of designs, for example in DE-PS 15 57 184 or in EP-PS 32 217. However, since vapors are now being removed again via line 9 , there is a risk that the volatile flavors would practically only be circulated. Apart from that, the operation of such thin film evaporators requires a great deal of specialist knowledge and high setting accuracy, which is why they are not always used.

Above all, however, the conche 8 is usually provided in the chocolate production as the last machine, if appropriate also a different refinement machine. In such a facility, the items to be treated are spread and anointed one last time for degassing and refinement. So here is the last opportunity to add an additive to the chocolate mass, whereupon the possibilities for the introduced flavoring agents to escape are reduced. It is therefore particularly preferred to supply the aromas caught in the container 23 via a line 41 to the conche 8 (or another refinement machine).

Fig. 2 illustrates the pre-mill 2 on a larger scale and in a cross section through its rotor shafts. The mill 2 is, as already mentioned, essentially designed in accordance with EP-PS 18 607, in accordance with the preferred embodiments presented in this EP-PS Darge. Accordingly, it has two stages, namely a first grinding housing 42 which can be fed with regrind via an opening 43 and a feeder 44 . In comparison to FIG. 1, it can be seen that the funnel 101 replacing the filling funnel 1 and the feed apparatus 44 are designed differently from the apparatus 4 illustrated in FIG. 1, but the design itself may be arbitrary.

Within the grinder housing 42 is provided with a corrugated Sta gate plate 45 around a rotor 46 equipped with blow bars. The stator plate 45 has an inlet opening 47 aligned with the opening 43 and an outlet opening 48 . Via the outlet 48 , the ground material is guided into a subsequent grinding housing 49 , in which a corrugated plate 50 is provided in the upper half, whereas in the lower half a sieve 51 indicated in FIG. 2 determines the maximum grain size. This grinder housing 50 is exposed via the sieve 51 to the immediate effect of the vacuum connection 3 , the grinder housing 42 is exposed to at most an indirect effect, since the grist fed to the grinder housing 50 via the opening 48 results in a certain seal.

The parts of the pre-mill 2 described so far are of a known nature. What is new, on the other hand, is that the liquid line 35 discussed with reference to FIG. 1 opens into the rotor space of the rotor 46 via injection openings 52 , 52 'of the grinding housing 42 or the stator plate 45 . It can be seen that the line 35 and the injection openings 52 , 52 'are arranged near the pair of openings 43 , 47 for the supply of the material to be treated, thereby ensuring that the material to be treated comes into contact with the injected treatment liquid from the beginning and in the course of Comminution is also mixed with it. Another advantage of this arrangement is that within the grinding housing 42 the vacuum pressure via the vacuum connection 3 only takes effect in a weakened form and therefore the liquid is only allowed time to act on the material to be treated without being too strongly influenced by the vacuum. This is particularly important if treatment fluids are injected with volatile components, which could be removed early by a too strong vacuum. Where this is not the case, it could even be an advantage to provide a vacuum connection within the Mahlge housing 49 in order to use the vacuum to suck in the treatment liquid and thus possibly save the pump 33 ( FIG. 1). However, exposure time is of course lost. In addition, it should also be mentioned that it may be advantageous to provide several injection openings 52 'and / or 52 distributed over the circumference of the grinding housing 42 . In this case, however, it is expedient to feed the injection openings (at least two) via a common collecting or distribution channel, so that only a single supply connection has to be provided. A further variant could be that in the area of the injection openings 52 , 52 ', injection nozzles are provided through which the treatment liquid is introduced into the regrind in a finely divided form.

From the above explanations it can be seen that the pre-mill shown in FIG. 2, in particular for cocoa, can advantageously be used for the most varied of treatments, with a longer exposure time (based on the entire process), a more economical consumption of treatment liquid or (for An injection of fats) a reduction in energy requirements and an improvement in quality.

If it was mentioned in connection with FIG. 1 that the bound aroma substances are preferably fed to a conche 8 , this will expediently be carried out in practice in such a way that first the chocolate mass, in particular (in the case of training as a dry conche) in a non-liquefied state, is filled, and only after the liquefaction of the chocolate mass, the flavorings contained in the liquid binder are added. This may (not only in the case of conches) possibly also synthetically produced or elsewhere extracted flavoring substances, ie they do not have to have been obtained from the same batch in the manner explained with reference to FIG. 1, although the volatile flavoring substances have been collected the vapor is a preferred embodiment. For example, it would be conceivable to obtain the flavoring substances from low-quality cocoa beans or even from other pome fruit, such as peanuts or soybeans, and to add higher-quality cocoa material, just as it would be possible, conversely, to upgrade less valuable cocoa material with a better flavor.

Claims (10)

1. A process for the heat treatment of core material which forms at least partially volatile aroma substances when heated, such as cocoa and / or cocoa products, characterized in that essentially isolated aroma substance is mixed in before, during or after the heat treatment. 2. The method of claim 1, wherein the during the heating brat is withdrawn, characterized net that the flavorings contained in the withdrawn broth, especially the pyrazine, recovered and the core good during, however preferred at the end and especially after the heat treatment be mixed again.   3. The method according to claim 2, characterized in
that the extracted vapor is supplied with a selective binder for flavorings contained in the vapor, in particular roasted aroma, such as pyrazine, and mixed with the partially condensed vapor in such a way that the flavorings are largely completely bound by the binder,
and that preferably at least one of the following features is realized:

• a) the binder contains at least one vegetative fat as an essential component, such as cocoa butter, peanut fat, coconut fat or the like;
• b) gaseous constituents remaining during mixing are drawn off, preferably during the mixing process;
• c) then a neutralizing liquid, such as lime milk, is added to the mixture of binder and condensed vapor component thus obtained in such an amount that the acids contained in the mixture are at least substantially neutralized, expediently the binder containing essentially the aroma substances Gravity or centrifugal force separation is separated from the aqueous salt solution obtained by neutralizing the acids.

4. The method according to any one of the preceding claims, in which a pre-grinding of the core material, in particular under vacuum takes place, characterized in that brothers from the pre-meal deducted stage and / or the abge containing the flavorings separated binder is fed to the pre-grinding stage. 5. Process for grinding cocoa, in which this is first fed to a pre-grinding stage, especially after one of claims 2 to 4, characterized in that already the pre-grinding stage a reducing sugar solution and / or aroma substance is supplied.   6. The method according to any one of claims 1 to 5, characterized characterized that the essentially isolated flavoring a finishing stage before the product is finished is supplied, for example a thin film evaporator, but preferably a conching stage, in particular the Aromatic substances containing, separated binder is supplied. 7. The device, in particular for carrying out the method according to claim 5, with a pre-mill for the core material, characterized in that a reaction medium supply line ( 35 ) opens into the grinding chamber. 8. The device according to claim 7, characterized in that the reaction medium supply line ( 35 ) is a liquid line, the other end of a storage tank ( 32 ), preferably via a pump ( 33 ). 9. The device according to claim 7 or 8, optionally with a vacuum connection to the pre-mill, characterized in that the reaction medium supply line ( 35 ) opens near the core feed opening ( 43 , 47 ), and that preferably the vacuum connection ( 3 ) at one from the mouth of the reaction medium supply line ( 35 ) is arranged. 10. The device according to claim 8 or 9, characterized in that the pre-mill ( 2 ) consists of at least two successive grinding stages, each with a rotor ( 46 ) and a stator ( 45 ), and that preferably the first grinding stage, the mouth ( 52nd ') And the following grinding stage of the vacuum connection ( 3 ) are assigned.