DE2141288A1 - Lightly rolled, cell-broken, ground roast coffee - Google Patents

Description

PATENT APPLICATION OR. EQQERt 5 Kü-ln-Lindeut. Hat ß i

THE PROCTER & GAMBLE COMPANY, .. Cincinnati (Ohio, USA)

Lightly rolled, cell-broken, ground roast coffee

The invention relates to lightly rolled, cell-broken, ground Roasted coffee that has the same appearance and the same bulk density as conventional ground roasted coffee particles, but opposite common ground roasted coffee products have a 10-30% strength Shows increase in flavor strength. The invention also relates to a process for the production of lightly rolled, cell-broken, ground roast coffee, which is characterized in that roasted ground coffee through a roller mill at a roller pressure of not above 270 kg / cm nip and preferably at a pressure in the range of 50-270 kg / cm nip. Particularly A roll pressure of 175-270 kg / cm roll gap and a roll surface temperature in the range of 10-95 ° C. are preferred Roller operation with a peripheral surface speed of 30-460 m / min.

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The term "roasted ground coffee" as used herein refers to a coffee product / that made in a conventional manner contains ground roast coffee particles, as well as decaffeinated forms thereof. The term does not include a lightly rolled, cell-broken, ground roast coffee, which is referred to here as "lightly rolled coffee", another flaked, ground coffee Roasted coffee. Although both lightly rolled, cell-broken coffee and flaked coffee by rolling ground coffee Roasted coffee is obtained, a distinction must be made between the two products. Lightly rolled coffee, as the name suggests, goes through Application of low rolling pressures generated. Even though the coffee cells are broken, the product still has the appearance of the usual ground roast coffee particles. Flaked coffee, on the other hand, is produced by using high rolling pressures. Although he too characterized by cell destruction, the broken cells are compressed by flaked coffee. Lightly rolled In other words, coffee is not both broken down and crushed, it is simply broken down into cells.

In the production of light-rolled, cell-broken, ground Roasted coffee is ground roasted coffee subjected to mechanical pressure by using conventional ground roasted coffee particles be passed through two parallel, smooth or highly polished rollers, so that the coffee particles passing between the rollers broken cells. The pressure exerted by the rollers on the ground roast coffee particles is controlled so that Cell rupture takes place without the cell flattening and at the same time -compression, which occurs in the formation of flaked, ground roast coffee.

When rolling ground roast coffee to make lightly rolled coffee, it has been found important to use several To control process variables other than the pressure mentioned above as critical. These additional variables include roll surface temperature, Roller circumferential speed, moisture

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hold of the ground roast coffee and grinding roller diameter. Another variable that is not as important as the variables mentioned above is, but contributes to the production of desirable products in high yields, is the particle size of the ground roast coffee.

The most important factor involved in the manufacture of light rolled, cell-broken, ground roast coffee has to be controlled is the roller pressure. The roll pressure is measured in kg / cm roll gap. "Nip" is a term used in the art to define the length of surface contact between two Rollers when they are idle. To illustrate, it can be thought of as a stretching over the full length of the reels Imagine the extending line that defines the points of contact between two rollers.

To produce lightly rolled, cell-broken, ground roast coffee, it is important that the rolling pressure does not exceed 270 kg / cm Nip lies. Roll pressures above 270 kg / cm roll gap favor the production of flaked coffee, which as mentioned above is a is cracked, flattened, and squashed coffee. Pressures in the range of 270-360 kg / cm roller gap favor the generation of some flaked coffee and some lightly rolled coffee and can be understood as pressures in a transition zone. However, pressures over 360 kg / cm nip always produce one larger proportion of flaked, ground roast coffee. Preferred pressures for producing lightly rolled coffee are in the range from 50-270 kg / cm roll gap and preferably in the range from 175-270 kg / cm roll gap. Although occasionally pressures of 50 kg / cm Roller gap can be applied, it has generally been shown that pressures significantly below 50 kg / cm roller gap to a product lead that does not have a significant amount of cell breakage as is characteristic of the lightly rolled product of the invention.

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The roller surface temperature mentioned here is in degrees Celsius measured and relates to the mean surface temperature of the rollers. The regulation of the surface temperature of the Milling rolling is achieved by controlling the temperature of a heat exchange medium or fluid passing through the inner core of the Rolling is performed. In general, the fluid, mostly water, is heated or cooled and passed through the interior of the rollers. As a result, the temperature of the roll surface, usually a smooth, highly polished steel surface, is regulated by the heat transfer. In actual operation, of course, the surface temperature is not exactly the same as the temperature of the heat exchange fluid and will be slightly higher, as there is a tendency when grinding coffee particles to produce lightly rolled coffee to increase the roller surface temperature. Accordingly, it is necessary to maintain a certain surface temperature The required temperature of the heat exchange medium depends on various factors, such as the type of metal on the roll surface, d. H. the metal from which the roll surfaces are made, the operating speed of the grinding rolls, and the heat exchange medium used.

General bring higher roll surface temperatures, the danger _fc a taste deterioration of the easily rolled, cell broken ground roasted coffee and which should be avoided. In contrast, lower roller surface temperatures can be used without any disadvantages. However, the use of temperatures below room temperature and accordingly the use of a coolant offers no particular advantages. In general, a satisfactory lightly rolled coffee can be obtained at roller surface temperatures in the range of 10-95 ° C. Temperatures below 10 C are not desirable, since cooling systems have to be used for this and the product obtained has a tendency to be brittle and easily breaks, which leads to the production of larger amounts of coffee fines and thus to an undesirable change in the product bulk density

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can lead. Temperatures above 95 C should be avoided, as these temperatures cause a noticeable deterioration in the taste of the coffee. To produce lightly rolled coffee with a bulk density practically equal to that of roasted ground coffee, a grinding roller surface temperature in the range of 43-83 ° C is preferred. If die'Walzenoberflächentemperaturen are in this range, the major portion of the resulting cell-broken, leiehtgewalzten coffee has a suitable structural relationship for securing a bulk density. which comes close to that of roasted ground coffee and the product shows little or no deterioration in taste.

The bulk density of roasted ground coffee is usually in

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Range from 0.38 g / cm to 0.50 g / cm and mostly in the preferred range from 0.42 g / cm to 0.48 g / cm. Such bulk densities generally correspond to the values of normal, medium and finer ground roasted coffees produced in the usual way Grist fineness. If the bulk density of the lightly rolled product is outside this range and e.g. B. is higher, would Consumers need considerably less than the usual amounts of coffee to produce a brew of a given strength. the then necessary changes in consumer habits could run into difficulties. Because of this, the manufacturing of a product with a bulk density similar to that of roasted ground coffee is significant because then the measuring method introduced remain applicable. The application of the process conditions explained here yields a product with the bulk density of ground roast coffee.

The roller circumferential speed is measured in meters of surface circumference, which passes the gap per minute, measured. In general, higher peripheral speeds mean that pressures in the lower part of the range described above can be used and for the production of a satisfactory lightly rolled coffee required bulk density. Conversely, at low

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Lower peripheral speeds are applied to pressures at or near the upper end of the range described above to produce lightly rolled coffee of the required bulk density. For the production of lightly rolled coffee according to According to the invention, peripheral roller speeds in the range from 30 m / min to 460 m / min should be used. At roller circumferential speeds above 460 m / min, the resulting lightly rolled product may have a tendency towards the cells both compressed and broken cells are what make the product gives an appearance dissimilar to the usual ground roast coffee. In addition, the frictional heat is at speeds over 460 m / min so high that the roll surface temperature cannot be kept at or below the maximum temperature of 95 ° C can. As a result, there is a considerable deterioration in taste of the lightly rolled coffee product. At roller circumferential speeds The production output of lightly rolled coffee for a technical company is less than 30 m / min too low. Particularly preferred roller circumferential speeds that have a simple temperature control and an expedient Output are between 100 m / min and 250 m / min.

In connection with the roller circumferential speeds, it should also be noted that the individual rollers of the roller grinding system are preferred operated at the same speed. However, you can also work with different roller speeds. When working with different roller speeds, ratio values of the roller speeds above 1.5: 1 are not expedient. When operating at different roller speeds, the roller speed ratio is preferably in the range from 1: 1 to 1.4: 1. In no case should the speed of the fastest roller exceed 460 m / min lie.

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In the production of lightly rolled, ground roast coffee, the moisture content of the lightly rolled, cell-broken coffee product should be between 2.5% and 7.0% by weight, with values of 3.0-6.0% being preferred. Accordingly, the moisture content of the ^{common roasted coffee particles used to make the lightly rolled coffee 1} should be in the range of 2.5% to 7.0%. With a moisture content of less than 2.5%, the usual ground roast coffee for the production of lightly rolled, cell-broken coffee is dry and tends to form fines instead of lightly rolled portions during rolling. On the other hand, values of the moisture content above 7.0% are to be avoided, since the tendency of the lightly rolled coffee obtained to become stale increases considerably at these higher moisture values. The choice of a moisture content of the usual roasted and ground coffee to be subjected to light rolling in the range of 3.0-6.0% results in the highest yields of lightly rolled coffee with at the same time little or no deterioration in taste, which is why this range is preferred «

The particle size of the material used to make the lightly rolled, cell-broken Common roasted ground coffee used in the product of the invention is not critical. From the manufacturing point of view of products with a bulk density similar to the usual ground roast coffee is preferred that the ground Roasted coffee particles have the usual particle size distribution, d. H. correspond to the sieve analysis values compiled in the following table.

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Clear mesh size
of the sieve in mm and
Sieve definition (mesh)
according to US standards more restrained
Proportion of the material to be screened
(%) passing through
Share of the sieve
good
(%) 1.68
(12 mesh) 0.0-18.0 1.19
(16 mesh) 0.0-46 0.84
(20 mesh) 15.0-50.0 0.59
(30 mesh) 7.0-30.0 0.42
(40 mesh) 4.0-15.0 3.0-8.0

In other words, this means that the ground roast coffee
for light rolling can have a normal, medium or fine grist fineness in accordance with the technical usage of these terms. The parameters of these grist fineness are in a 1948 publication of the US Department of Commerce, "Simplified Practice Recommendation" (see "Coffee Brewing Workshop Manual", page 33, publisher: Coffee Brewing
Center of the Pan American Bureau) and compiled in the following table »

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Grist fineness
of roasted coffee Payback
of the grist
Seven with L
1.168 mm
(Tyler 14) ener share
s in *% at
.MW from
0.589 mm
(Tyler 28) Continuous at
part (%) at LMW *
from
0.589 mm (Tyler 28) normal 33 55 12th middle 7th 73 20th fine 0 70 30th

* L.M.W. = clear mesh size.

Of the usual grist fineness mentioned above, the normal fineness is particularly preferred.

In connection with the particle size, it has already been mentioned above that the lightly rolled, cell-broken coffee product of the invention has a bulk density substantially similar to that of conventional roasted ground coffee. It is accordingly It is important that the light rolling process of the invention does not cause a size reduction, but only causes cell disruption. That Starting or input material from common ground roasted coffee ■ particles has the same size classification as the product of the process obtained lightly rolled cell-broken coffee, the only difference being that it is exactly like ground coffee Roasted coffee-looking process product has considerable cell disruption. The cell rupture is mostly such Kind that 20-65%, especially 40-65%, of the cells are destroyed.

The diameter of the grinding rollers used determines the entry angle of the roller gap. The entry angle of the nip has a direct effect on the extent of the possible size reduction and accordingly on the bulk density of the

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resulting lightly rolled coffee. To make the lightly rolled coffee described above with the required Bulk density in the range of the bulk densities of ground roast coffee is preferred that the roller diameter in the range from 150-765 mm, preferably 225-640 mm. When using rollers with a diameter of less than 150 mm, the The passage of the coffee particles through the gap can be made more difficult or delayed, so that the throughput of the usual ground Roasted coffee, which is subjected to cell breaking to produce the lightly rolled coffee, is inexpediently reduced. Grinding rollers with roller diameters of over 765 mm are not readily available.

From the foregoing it can be seen that the ranges of each of the discussed variables of the rolling process described closely related to and mutually influencing each of the other variables of the process. A change one variable can often directly cause the change in another variable. For example, one company runs with high roller pressures over 270 kg / cm roller gap for cell breaking with simultaneous compression, which in turn creates a flocculated product. Although roller peripheral speeds Above 460 m / min can produce slightly rolled coffee of the required bulk density, the lightly rolled coffee is because of the increase in roller surface temperatures accompanying the high speed a worse structural context and often either a deterioration in taste or a considerable reduction in size with the formation of Have suffered fines. The light rolling process according to Invention represents the mutual relationship and interaction of roller pressure, roller temperatures, coffee moisture values and Roller diameter, roller peripheral speed and, to a lesser extent, the particle size of the usual ground roast coffee charged.

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The amount of feed of the usual ground roast coffee particles in the rolling mill is not critical. It can be fed with excess (Accumulation feed) or shortfall feed can be worked, provided that only the process variables described above are within the prescribed areas must be maintained. The preferred accumulation feed is determined by the fact that there is excess on the rolling mill There is a large amount of coffee and waiting for it to pass through the gap. This is the opposite of underfeed. In general, the pressure should be reduced when using underfed be at the lower end of the pressure range to ensure that cell breakage is achieved without simultaneous compression with flake formation.

Some exemplary embodiments of the invention are given below.

example 1

180 kg of a mixture of 25% high quality Arabica varieties, 43.75% Brazilian varieties, 6.25% low-value Arabica varieties and 25% Robusta varieties were roasted in a "Thermolo" roaster at air temperatures roasted at 200-290 C. The final roasting temperature was 220 ° C. and the total roasting time was 16 minutes Quenched 26.5 liters of water and grind the mixture to normal fineness in a grinder ("Gump pilot grinder"). Of the Moisture content was 4.24 wt%. The bulk density of these • common ground roast coffee particles was 0.451 g / cm. the The bulk density values given here relate to the tamped bulk density and to the gross density of a large number of particles measured after being vibrated in a manner as described in "Coffee Processing Technology" by Sivetz, Avi Publishing Co., Westport, Conn., 1963, pp. 130-131, vol. 2. These usual, ground, roasted coffee particles of normal fineness were used to make lightly rolled, cell-broken, ground roast coffee in the following way: The coffee became a Lehman rolling mill with two rollers with damming with a diameter of 330 mm and a length of 810 mm

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carried. The roll pressure was 101.5 kg / cm roll gap. The roll surface temperature was at 60 C, the roller circumferential speed of each roller was 56 m / min. The proportion of during this and in the following examples the actual effective nip was only 18 cm.

The product thus obtained showed a moisture content of

3. 4.0% and a bulk density of 0.44 g / cm, what practical

Purpose is to be regarded as identical to that of the bulk density of the usual ground roast coffee particles fed in. The visual Examination of the product showed that it was identical in terms of its fc appearance to conventional ground roast coffee particles is. The microscopic examination, on the other hand, showed a considerable proportion of cell breakage.

A group of four experienced coffee testers made cup coffee from the lightly rolled, cell-broken coffee in the following way Way hers

The amount of lightly rolled cell-broken coffee used was 7.2 g per cup, the amount of water used per cup was 178 ml. The coffee was placed in a conventional percolator and allowed to percolate until the temperature rose to 82C. Now the coffee infusion was poured into cups and from the Test group rated. The testers compared the taste of coffee from the lightly rolled, cell-broken coffee described above Coffee was made with a coffee drink made from commercially available roasted coffee ("Folger") of normal grind fineness had been prepared. The testers found that the beverage made from the cell-broken, fine-rolled coffee about 15% stronger in the taste impression than the coffee drink prepared from the usual ground roast coffee.

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Example 2

It was according to the method of Example 1 using the ground roast coffee mixture described there with the following
Changes worked:

The pressure at the nip was 175 kg / cm. The amount of common roasted coffee used to make lightly rolled cell-broken coffee was 44.3 kg. The stamped
The density of the product was 0.44 g / cm and the roller peripheral speed was 152 m / min. The product visually had the appearance of roasted ground coffee and, when examined by a panel of testers in that described in connection with Example 1, showed
Compared to the flavor strength of the ground roast coffee, an average increase in the flavor strength of 20%.

Example 3

Example 1 is repeated with the following changes:
The roll pressure is 268 kg / cm roll gap. The amount of the common roasted ground coffee used is 10.2 kg. the
The roller speed is 229 m / min, the roller surface temperature is 36.7 ° C and the product bulk density is 0.44 g / cm
Visual inspection of the product shows that it looks exactly like normal roasted coffee. The taste test
by a group of testers as described in Example 1 shows that the product is on average about 25% stronger in taste than coffee beverage which was made from a conventional ground roast coffee product of normal grind fineness.

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Claims (9)

2H1288 claims 1. Ground cell-broken roast coffee that bleaches it Looks like normal ground roasted coffee particles, but compared to these offers a 10-30% increase in flavor strength, characterized by that 20-65% of the cells of the coffee are broken but not compressed to form coffee flakes 'are, and characterized by a bulk density of 0.38-0.50 g / cm. 2. Roasted coffee according to claim 1, characterized in that 40-65% of the cells of the coffee are broken are not compressed to form coffee flakes. 3. Roasted coffee according to claim 1 or 2, characterized by a bulk density of 0.42-0.4 8 g / cm. 4. Process for the production of ground cell-broken material "Roasted coffee according to one of claims 1-3, characterized in that that roasted ground coffee with a moisture content of 2.5-7% at a roller pressure of not over 270 kg / cm roller gap through a roller mill for the formation of lightly rolled, cell-broken aemahlenem roast coffee with a bulk density of 0.38-0.50 g / cm, which has the same appearance as conventional ground roasted coffee particles, but int compared to these offers a 10-30% increase in flavor strength. 5. The method according to claim 4, characterized in that the roll pressure in the range of 50-270 kg / cm roll gap, in particular is in the range of 175-270 kg / cm nip. · 209809/0272 . _15th 2H1288 6. The method according to claim 4 or 5, characterized in that the lightly rolled coffee has a bulk density of 0.42-0.48 g / cm. 7. The method according to any one of claims 4-6, characterized in, that the rollers of the rolling mill with a roller peripheral speed from 30-460 m / min, in particular from 100-245 m / min. 8. The method according to any one of claims 4-7, characterized in, that the surface temperatures of the rolls of the rolling mill in the range from 10-95 ° C, in particular in the range from 4 3-83 ° C. 9. The method according to any one of claims 4-8, characterized in that that the percentage of broken cells in the lightly rolled coffee is 40-65%. R / Ni 12.8.71 2
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