Extracts of vegetable materials

The invention now relates to the recovery of a new industrial product consisting of extracts of vegetable materials in Koraform. The new product is therefore especially¹⁰ remarkable because it has the form of grains which are instantaneously soluble in water and which have a porous and continuous structure, a surface without roughness and a mass per volume (density) of 50 to 300 g / l.

The inventive method for producing such extracts in Comform is characterized in that an extract of plant materials in powder or paste form at ¹⁵ extruded at a temperature of 60 to 125 ° C in a space in which there is a subatmospheric pressure of 0.01 to 0.3 bar, and that the extruded product is cut into fragments.

The extracts according to the invention are preferably extracts of coffee, chicory and other coffee substitutes, black tea and other teas, such as peppermint, lime blossom, verbena, chamomile etc.

²⁰ Although US Pat. No. 3,637,397 discloses a process according to which soluble coffee in the form of expanded beads is to be obtained. To this end, a batter of moistened soluble coffee is prepared, cooled to form hardened plates, ground to pieces and blown under the influence of heat and vacuum, and finally granulated. The process disclosed therein has no reference whatsoever to the invention's direct extrusion of a powder or powder ²⁵ Paste form present thermoplastic starting material into a space in which there is a sub-atmospheric pressure.

The drawings illustrate an example of an embodiment of a product obtainable according to the invention. FIG. 1 shows a 12,8-fold enlarged schematic view of a cut grain of diameter 6 mm made according to the invention. 2 shows a representation of³⁰ According to the invention produced grains.

The present invention produced grains have the property that they dissolve in water almost instantaneously. So they are instantly soluble in hot water. In addition, they are unexpectedly soluble in cold water almost instantly.

The grains have a porous and vesicular internal structure -1--, as shown in the drawings (Fig.l) ³⁵ is shown. This structure is relatively regular and can be compared to the structure of a sponge. The average dimensions of the bubbles -2- can vary between wide limits depending on the production conditions. They are for example between a few 1/100 and 1 mm. Because of their overall homogeneous structure and lack of major discontinuities, with the exception of occasional discontinuities, the grains obtainable in accordance with the present invention differ⁴⁰ basic of grains obtained by agglomeration of finer particles.

The external appearance of the grains differs from their internal appearance. They have a surface -3- which is relatively smooth and has no roughness. The holeiness, which has its cause in the outward opening bubbles, is largely mitigated. In other words, the grains have a fine porous skin of very small thickness. The appearance of these grains reminds⁴⁵ amazing to that of pumice.

The mass per volume of the grains is between 50 and 300 g / l; it is a direct consequence of the porous and vesicular structure and can be determined by appropriate selection of the manufacturing conditions.

The dimensions and shapes of the grains can also be selected by an appropriate selection of the 50th

Conditions of production. In practice, the minimum dimensions which can be realized without major difficulties are of the order of 1 to 1.5 mm, that is to say that the grains are retained by a 1 mm mesh sieve. Preferably, grains with dimensions between 2.5 and 15 mm are produced.

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The grains produced using a single nozzle (or more identical nozzles or one or more nozzles)

Multiple nozzles with identical openings) and produced by regular cutting of the extrudate, all have almost the same shapes and dimensions, with no oversize or undersize present. Some forms are shown by way of illustration in FIG. If at the same time⁵ several different nozzles are used, or if an irregular cutting sequence is used, then it is easy to produce a final product consisting of grains of various shapes and dimensions. This result can also be achieved by mixing the product of a first preparation with the product of another preparation.

In general, the grains are relatively hard and resist very well to crushing.

¹⁰ For example, a whole grain of a soluble coffee extract in the form of a 6 mm diameter sphere has a compressive strength of the order of 2.5 to 7.5 Newtons. In comparison, the soluble coffee consisting of grains is, overall, less disruptive than a lyophilized or agglomerated coffee powder of the same apparent density.

The Lebensmittelkömer available according to the invention, the water content up to 6% of its weight ¹⁵ can go on dry solids, have a very high absorption capacity. They can hold up to 20% of their weight in fats, flavorings, colorants, etc. In practice, however, a content of fats of 5% is not exceeded in order to prevent the formation of fat globules in the made beverage. Despite this absorption capacity, these grains are only slightly hygroscopic, so that they can be stored for several days in the atmospheric moisture without becoming sticky.

²⁰ In the method according to the invention for the preparation of these grains, an extract in powder or paste form is extruded into a container in which a subatmospheric pressure prevails.

The extract of vegetable materials must be able to be extruded, that is to say that it may be thermoplastic or contain a high content of thermoplastic constituents. The term of thermoplasticity, which is a softening under the influence of heat and given pressure and pressure

Hartwerden includes when cooling, in the case of a paste is to be understood without further ado. In the case of a powder, this term means that the substances constituting the powder fuse together under the influence of heat and, if necessary, pressure, to make a more or less malleable soft mass.

The water content of the extract (which has the form of a powder or a paste) is a ³⁰ important factor, but by no means critical, since it can be varied within a wide range, practically up to 10 wt .-%, based on dry solids. It has a direct influence on the properties of the finished product, and one can modify the water content of the starting extract accordingly to achieve a specific finished product.

The temperature of the extract in the extruder is of course an essential factor of the invention³⁵ In accordance with the method, since they the plasticity of the extract and thus the extrudability by the

Extrusion nozzles determined. They are sufficient to achieve this plasticity (about 60 ° C), but so they do not cause deterioration of the treated extract. It can be said that 125 ° C is the upper limit, which is best not exceeded. It may be appropriate to take certain precautions to prevent the temperature of the nozzles or in the area of ​​the⁴⁰ Nozzle this limit under the influence of the compressive forces prevailing in front of the nozzles does not exceed. These compressive forces are usually between 1 and 10 bar during normal operation.

The diameter of these small orifices, which determine the value of the pressure in the extruder, can be freely selected with reference to the dimensions which the finished product will have. Extrusion, however, is difficult to perform in practice when the openings⁴⁵ Dimensions below 0.25 mm. Nozzle diameters on the order of 0.5 to 5 mm are the optimum values ​​for the preparation of coffee extract grains from powder extracts having a moisture content of 2 to 6%. The nozzle shape is without much influence. By using short or long nozzles, conical nozzles or two-part nozzles (one part narrow, one part farther), no much better results are obtained than when the more conventional cylindrical nozzles⁵⁰ be used. In order to give the finished product a certain shape, it is possible to use nozzles with a non-circular cross section, for example with a quadrangular, oval or trilobal cross section. In order to influence the surface finish of the extruded product and thus the grains obtained, it is also possible to use cooled nozzles or nozzles whose outer Teü is cooled.

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By contrast, the subatmospheric pressure or the vacuum in the container following the nozzles is a very determining element. If there is no vacuum, then the product that passes through

Extrusion of an extract obtained in the usual for operations of this kind

Temperatures is maintained, not the desired expanded texture. In contrast, the⁵ The presence of a vacuum at the exit of the nozzles partly results in an at least partially rapid removal of the water in the form of vapor and the gases initially contained in the extract, and at the same time a sharp lowering of the temperature, thereby imparting the desired texture and hardness to the extruded product. In practice, the subatmospheric pressure is in the order of 0.01 to 0.3 bar, u.zw. in particular due to considerations regarding the¹⁰ Technology and the cost.

In one embodiment of the process according to the invention, the starting extract in powder or paste form is introduced by suitable feeding means under atmospheric pressure, under pressure or under vacuum and if necessary under an inert gas into an extruder whose body has a temperature between 60 and 100 ° C. This extract is then used with¹⁵ By means of a corresponding device, such as a piston (batch process) or a single or double screw (continuous process) with fixed or variable pitch and optionally with a heating device, moves to or to the extrusion nozzles, gradually under the influence of Heat and the pressure softens. The hot extract then passes through the extrusion dies maintained at a temperature between 70 and 90 ° C and reaches ²⁰ then the container in which vacuum prevails. This container can also be called an expansion chamber. Under the influence of the sharp decrease in pressure, part of the water (up to 50%) and the gases contained in the extract are sucked out, during which time the temperature of the extract falls by a few 10 ° C. In this case, an expanded product is obtained in the form of a relatively hard and porous strand.

²⁵ According to a first variant, this strand is first allowed to expand and then regularly cut, for example with the aid of a rotating knife. The resulting grains, which are uniform in size, are reminiscent of chopsticks or slices.

According to a second and preferred variant, the strand is cut before expansion, ie very close to the extrusion dies and under vacuum. The resulting chopsticks are then³⁰ inflated, the grains being obtained in the form of spheres or ovoids of similar dimensions.

According to a third embodiment, the rods obtained by cutting the strand shortly after exit from the nozzles are caught in individual molds in which, as they expand, they assume the shape of this form, for example the shape of a coffee bean.

³³ As mentioned above, the use of vacuum allows the original extract to be textured without having to raise it to a high temperature. Therefore, the sensitive substances of this extract, in particular the flavor substances, largely protected. For this reason, the grains obtained have taste and odor qualities which can be compared with those of the non-extruded starting extract. In addition, they are due to their⁴⁰ porous structure capable of receiving larger amounts of various substances, such as fats, flavoring agents, etc. It is therefore possible, if desired, to spray on these grains flavoring substances diluted with a suitable carrier. It is also possible to post-treat them, for example nachzutrocknen.

According to a preferred embodiment of the method according to the invention is called thermo⁴⁵ plastic extract uses a powder called instant beverage (coffee, black tea, chicory, coffee plus chicory, etc.) obtained by atomization, lyophilization or other drying method, the grain shape being of minor importance. If necessary, the water content of this powder is adjusted to 2 to 6%, after which this powder is then poured into a screw extruder, which has a temperature of 80 to 100 ° C and with ⁵⁰ Nozzles of a diameter of 0.5 to 5 mm is equipped. The vacuum in the expansion chamber is 0.05 to 0.15 bar.

According to an advantageous application of this preferred embodiment, the extruder is equipped with a simple drying tower (ie, that it is not equipped with a means for recycling

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Fines is equipped), so that the emerging from the drying tower powder passes directly into the extruder.

The expanded strand is cut in vacuum immediately after exiting the extrusion die. The resulting grains then fall to a floor and can be transported after completion of expansion by means of a lock from the expansion chamber. These granules generally have a mass per volume of between 100 and 200 g / l in coffee and coffe / chicory mixtures and between 80 and 150 g / l in black tea. Depending on whether the starting powder was a deflavored or a normal powder, the grains obtained may be flavored or their flavor enhanced. For this purpose, for example, a dispersion of coffee aroma substances in a coffee oil can be sprayed onto the grains from a coffee extract. It is also possible to fill the vacuum in the expansion chamber in which the grains are located by means of an atmosphere laden with coffee aroma substances, in particular with a carbon dioxide atmosphere.

Examples

Used devices:

Coating funnel with a capacity of 10 1.

Extruder with a theoretical throughput of 20 kg / h, a steam-heated body, a screw of constant pitch 42 mm in diameter and 21 cm in length and with a pressure of 1.

Expansion chamber with a capacity of 80 liters, equipped with a liquid ring pump.

Cooler.

Rotary knife.

coolable vibrating bottom.

Outlet lock.

The following examples have been developed with the aid of these devices.

Example 1: With the aid of the above-described apparatuses, wherein the extruder is equipped with four cylindrical extrusion nozzles of 2.9 mm diameter, 10 kg of a lyophilized instant coffee powder having a water content of 2.5% are extruded.

The working parameters are as follows:

Temperature of the body of the extruder: 95 ° C

Extrusion snow speed: 80 rpm

Speed ​​of the rotary cracker: 240 rpm

Pressure in the expansion chamber: 80 mbar

The grains are collected on a vibrating tray which is cooled with liquid nitrogen before being put into operation.

In this way, about 9.8 kg of coffee extract grains are obtained, which are the size of a small pea, a pleasant brown color and a mass per volume of 160 g / 1. These grains are almost instantly soluble in cold water. By dissolving these grains in hot water in an amount of about 15 g / l, an instant coffee is obtained which, according to the advice of taste experts, has lost none of its taste qualities compared to a coffee prepared with the aid of the starting extract.

Example 2: With the aid of the above-described apparatus, wherein the extruder is equipped with a nozzle with four cylindrical openings of 3.5 mm diameter, 10 kg of atomized instant coffee powder with a water content of 2.5% are extruded.

The work parameters are as follows:

Temperature of the body of the extruder: 100 ° C

Extrusion screw speed: 60 rpm

Rotary blade speed: 370 rpm

Pressure in the expansion chamber: 40 mbar

The grains are collected on a room temperature vibration tray.

In this way, about 9.8 kg of coffee extract grains with brown color, the size of small peas and a mass per volume of 160 g / 1 are obtained. These grains are almost instantly soluble in cold water. By dissolving these grains in hot water in an amount of about 15 g / l

- 6 No. 347765 einο an instant coffee is obtained, which according to the information of taste test persons has not lost its taste qualities compared to a coffee prepared from the starting extract.

Example 3: With the aid of the devices described above, the extruder is equipped with a nozzle with twenty-four cylindrical openings of 3 mm diameter ⁵ 10 kg of an atomized Instnatkaffeepulvers extruded with a water content of 2.7%.

The working parameters are as follows:

Temperature of the body of the extruder: 100 ° C

Extrusion screw speed: 80 rpm

Rotary blade speed: 250 rpm

Pressure in the expansion chamber: 45 mbar

The grains are collected on a room temperature vibration tray.

In this way, about 9.8 kg of coffee extract grains having a brown color, the size of small peas and a mass per volume of 160 g / 1 are obtained. These grains are flavored by incorporation of 0.5% by weight of an emulsion containing 1 part of a condensate of volatile¹⁵ Coffee aroma substances and 2 parts of a carrier consisting of coffee oil. Finally, the flavored grains are conditioned under an inert atmosphere inside closed containers.

When opening these containers, the grains show a pleasant smell of freshly roasted coffee. By dissolving these grains in hot water in an amount of about 15 g / 1 becomes²⁰ Instant coffee, the quality of which is rated high by taste experts.

Example 4: With the aid of the apparatuses described above, wherein the extruder has a nozzle with six cylindrical openings of 2.8 mm diameter, 10 kg of atomised instant tea powder with a water content of 3% are extruded.

The working parameters are as follows:

²⁵ Temperature of the body of the extruder: 105 ° C

Extrusion screw speed: 40 rpm

Rotary blade speed: 550 rpm

Pressure in the expansion chamber: 40 mbar

The grains are collected on a room temperature vibration tray.

³⁰ In this way, about 9.8 kg of tea extractives having the size of small peas, a markedly brown color and a mass per volume of 92 g / 1 are obtained. These grains are almost instantly soluble in cold water. By dissolving these grains in hot water in an amount of about 3.5 g / 1, an instant tea is obtained which, according to the information of taste experts, has lost none of its taste qualities as compared to a tea prepared from the starting extract.