JPH074164B2 - Roasted coffee particles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to particles for filling a coffee bag, a method for producing the same, and an apparatus therefor. More specifically, a new type of crusher is used to produce coffee particles having a different shape and structure from the conventional one. By blending multiple types with different particle sizes, coffee particles with a richer flavor and aroma can be obtained.

[0002]

2. Description of the Related Art Currently, coffee is widely used in daily life, and interest in its taste and aroma is increasing. It is well known that the taste and aroma of coffee change depending on factors such as the type of beans, blending ratio, degree of roasting, and how to make it. However, reflecting the recent living environment, coffee has a higher taste and aroma. The scent is required. Moreover, there is a strong demand for coffee that can be easily brewed in a short time, and an increasing number of coffee beans are roasted in advance, ground and then packed in a bag. Therefore, many attempts have been made to enhance the taste and aroma of coffee for bag filling.

Conventionally, a small minced crusher is used for small-scale coffee shops and households for roasting and crushing coffee beans, and a roll mill is used for large-scale crushing. All of these crushers are of a type in which beans are crushed through a rotating cone-shaped crush plate or slits between rolls. Further, the crushed particles do not blend with each other, and are used as they are in a coffee bag or the like.

These pre-prepared and bag-filled coffees are used as regular coffees or coffee bags for immersing in hot water. However, from the enthusiasts who are familiar with the taste of coffee, they were prepared by a careful method. It has been pointed out that it is still insufficient in comparison with coffee in terms of richness, aroma, mixing of fine powder into coffee, bitterness, sourness and the like.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a clear coffee liquid color, an excellent aroma and an excellent aroma that can sufficiently satisfy the demands of coffee enthusiasts even for coffee prepared in advance and filled in a bag. It is an object of the present invention to provide coffee particles which have a rich taste, an appropriate bitterness and sourness, and are not mixed with fine powder.

[0006]

Means for Solving the Problems As a result of research on the crushing method of coffee beans after roasting and the influence of the shape of particles on the taste of coffee, the present inventors have found that the conventional crushing method of grinding does not It was found that a coffee having an excellent aroma and rich taste can be obtained by the method of crushing by, and by further adjusting the particle size distribution by blending coarse particles and fine particles, the bitterness, the sourness, etc. were balanced. The present invention has been accomplished based on the finding that a desirable taste can be obtained.

That is, coffee beans are roasted and then ground by a crushing type crusher, and the particle size distribution is at least 1 in a range of particle diameters of 0.5 mm or more and 0.4 mm or less.
Roasted coffee particles having two peaks and coffee beans are crushed by a crushing type crusher to prepare at least two kinds of particles having different center particle sizes,
By mixing them, the particle size distribution is 0.5 mm or more and 0.
A method for producing roasted coffee particles, characterized by blending so as to have at least one peak in a region of 4 mm or less, and an apparatus for producing the same.

The present invention will be described in detail below.

The coffee particles of the present invention must be particles crushed by a crushing type crusher. Here, the crushing type crusher has a structure as shown in FIG. 1, and a pair of facing crushing rolls (1a, 1b) ─ (4a, 4b) are stacked and arranged in several stages. As shown in Fig. 2, the cross section is in the shape of a saw tooth, and the ridges 7 and valleys 8 of a pair of rolls are in mesh with each other, but the ridges 7 and valleys 8 of the two rolls are not in close contact with each other. As shown, a constant interval is maintained. It should be noted that the spacing between the teeth of the saw teeth (roll pitch) and the spacing between the rolls (roll clearance) are the largest in the uppermost roll, and are gradually reduced toward the lower stage.

The roasted coffee beans enter through the raw material supply port 5, are crushed by the slits 1c of the uppermost rolls 1a and 1b, and are sequentially slits 2c, 3c and 4 of rolls 2a, 2b-4a and 4b.
It is discharged from the outlet 6 through c. The diameter and the number of revolutions of each pair of grinding rolls are the same.

When the raw material particles 9 are crushed by the slits of the roll, as shown in FIG. 2, the raw material particles 9 have a shape as if they were bridged between the tooth peaks 7 and 7'of the roll, and the rolls on the opposite side. The central portion 9'of the particle is impacted by the peak 7 "of the particle. By the impact, the particle radially cracks from this point of force and breaks into several pieces. Is
It is also considered that the material of the roasted coffee beans has an effect. The crushed particles are composed only of crushed surfaces, the so-called virgin faces, whose surface texture is not ground. Therefore, the scent trapped in the micropores generated by roasting does not escape, and the fat contained in the coffee particles is not squeezed out and adheres to the surface of the particles. Therefore, deterioration of the taste and aroma of coffee due to the oxidation of fat is prevented, and it can be stored in a fresh state for a long time. This is the most outstanding feature of this grinding method.

The crushed raw material enters the slits of the rolls in the next stage, but the gap between rolls (roll pitch) and the gap between rolls (roll clearance) are narrower than those in the upper rolls. The particles are successively finely ground. Further, the particles already finely pulverized in the upper stage pass through the next stage as they are, and only the coarse particles are pulverized. Therefore, when passing through several stages of pulverizing rolls, coffee particles having a uniform particle size and very few fine powder are obtained.

[0013] At present, a roll mill is mostly used for crushing roasted coffee beans on a large scale. In the roll mill, the raw material is usually passed through the slits of one pair or two pairs of grinding rolls to be ground. The surface of the rolls has many smooth surfaces without grooves, and the distance between the rolls (roll clearance) is much narrower than that of the crushing type crusher, and the pair of rolls often have different rotational speeds. Therefore, since the particles are crushed in the presence of the relative velocity, the crushed particle surface is in a considerably ground state.

Therefore, the shape of the particles crushed by the crushing method is significantly different from the shape of the particles crushed by the conventional roll mill or small minced crusher. The angle of the particles crushed by the crushing method is almost acute, and when observing the surface of the crushed particles with a microscope, the tissue of carbonized beans remains as it is and the tissue is not destroyed at all.
The surface of the particles is composed only of so-called virgin faces. Scanning electron micrographs of the shape and surface texture of the particles crushed by the crushing method are shown in FIGS. 3, 4, 7, and 8.
On the other hand, the particles crushed by a roll mill or minced crusher have rounded corners and the surface texture is clearly ground. For comparison, scanning electron micrographs of the shape and surface texture of particles crushed by a roll mill are shown in FIGS. From these photographs, it is observed that a large number of fine particles generated by grinding adhere to the surface of the particles crushed by the roll mill.

Further, the roasted coffee beans are crushed by the crushing type crusher of the present invention and the roll mill so that the central particle sizes are the same, and the particle size distributions are compared. The crushing type is better than the roll mill. The particle size distribution is extremely sharp.
In addition, when one crushed particle is picked up and scattered on paper, each particle is scattered in the crushing type, but the particles of the roll mill form lumps and are not uniformly dispersed. It is considered that this is because many fine particles are attached to the surface of the coarse particles. Therefore, when the particles are picked up with a fingertip, the particles crushed by the crushing method are rough, but with a roll mill, they are tacky and stick to the fingertip. In this respect as well, a remarkable difference is recognized in the properties of the crushed particles of both.

The difference in the shape, texture, particle size distribution of these particles, and the adhered state of the fine particles to the coarse particles is that the crushing method is a method in which roasted beans are crushed by applying an impact, whereas a roll mill is It is considered to be generated by the grinding method.

The particle size distribution of the particles of the present invention is such that the particle size is 0.5 m.
It must have at least one peak in the region above m and below 0.4 mm. Here, the particle size distribution is, as described in Example 2 to be described later, shown by sieving with a 7-step sieve having an opening of 0.25 to 1 mm. For example, the weight ratio of particles of 0.25 to 0.3 mm is 0.25 mm. It is displayed as an ingredient of.

Next, the particles crushed by the crushing type crusher have an extremely unique shape as compared with the conventional product, and the relationship between the particle size and the aroma and flavor of coffee was examined.

As a result, the coarsely ground particles having a central particle size of about 0.6 mm are suitable for producing the aroma and mild taste of coffee, and are particularly necessary for producing the plump aroma characteristic of coffee. It turned out to be a non-potent ingredient.
It was also found that finely ground particles having a central particle size of about 0.3 mm are suitable for producing an umami, which has a heavy weight on the tongue, that is, a so-called mellow taste, but at the same time produce a strong bitterness and sourness.

Based on the above test results, the result of blending coarsely ground particles and finely ground particles so as to have at least one peak in the region where the central particle diameter is 0.5 mm or more and 0.4 mm or less It was found that coffee having a high aroma, a rich taste, a clear color, and an appropriate balance of bitterness and acidity can be obtained. Particles having a particle size distribution such that the central particle diameter falls in the middle range were also tested, but only a result in which the flavor of coffee was considerably poor was obtained.

A test for the taste and aroma of coffee is about
Although it was conducted by a sensory test by 10 panelists, as shown in Examples below, a fairly clear difference was observed. Furthermore, the particles of the present invention are excellent in extractability, and when they are enclosed in a coffee bag and shaken in hot water, coffee can be added in a shorter time than conventional products. Furthermore,
Since the coffee particles are free flowing, the filter does not become clogged during extraction and so-called drainage is good. In addition, fine particles are not mixed in the coffee liquid, and the color of the coffee liquid is transparent and beautiful. Therefore, it is suitable not only for regular coffee but also for filling coffee bags.

The center particle size of the peak of coarsely ground particles is 0.5.
.About.1.0 mm is preferable, and 0.5 to 0.85 mm is more preferable. The center particle size of the peak of finely ground particles is preferably 0.25 to 0.4 mm.

The size distribution of coffee particles is such that the center particle size is
If the distribution has at least one peak in the region of 0.5 mm or more and 0.4 mm or less, the effect of the present invention can be obtained, but the central particle size is 0.4 mm with respect to the maximum peak height of 0.5 mm or more. The ratio of the maximum peak heights of mm or less is preferably 0.4 to 1.0, more preferably 0.6 to 0.8. It should be noted that when the roasted coffee beans are made shallow, the ratio of both peaks, which is the optimum flavor, tends to be closer.

In the embodiment relating to the production method of the present invention, the particle size distribution of ground coffee has a particle size of 0.5 mm or more and 0.4 m or less.
When preparing particles having at least one peak in the region of m or less, after roasting coffee beans, grind with a crushing grinder to prepare at least two kinds of particles having different central particle diameters, and blend them. There is a need to.

When roasted coffee beans are crushed by a crushing type crusher, particles having a sharp particle size distribution and only one distribution peak are obtained. Therefore, at least two types of particles with different central particle diameters, for example, a central particle diameter of 0.6m
Particles coarsely ground to be over m and the central particle size is 0.4 m
This is a method of preparing finely ground particles so that the particle size is less than m, and blending them. The preferable center particle size of the coarsely ground particles and the finely ground particles and the ratio of the peaks of the both are as described above.

When preparing coffee particles, the raw material is usually made by blending many kinds of coffee beans, but the raw material beans once blended are roasted and crushed as they are to be commercialized. There is no such thing as making various types of crushed products with different particle size distributions and blending them to make products. According to the method of the present invention, various kinds of pulverized products having different particle size distributions are prepared and blended so as to obtain an optimum particle size distribution, and the excellent effects of the present invention are obtained for the first time.

[0027]

EXAMPLES The present invention will be described in more detail below with reference to examples.

(Embodiment 1) A flow sheet and a control system of a production system of the present invention will be described with reference to the drawings.

FIG. 3 shows a flow sheet of the production method of the present invention. The roasted coffee beans are roughly crushed by a crusher type crusher 10, and then a coffee bean peel and dust are removed by a shifter 12, and a certain amount of coarse particles is weighed by a weighing tank 13. This is because when the coffee beans are mixed in the coffee particles, they do not bite into the next fine pulverizer and inhibit the pulverization. Further, a part of the coarse particles is further finely pulverized by the crushing type pulverizer 11 and weighed in the measuring tank 14 so as to have a constant ratio to the coarse particles. The number of coarse pulverizers and fine pulverizers is not limited to one per line, and a plurality of units can be used. Next, the coffee particles of the present invention are obtained by uniformly mixing the two with the mixer 15.

Further, the control device 16 is composed of a combination of a crushing crusher and a shifter which are continuously operated, and a metering tank and a mixer which are batch operated, which is an optimum on / off control and coarse particles and fine particles. It is controlled so that the mixing ratio of is always constant. For example, when the measuring tank 14 has reached the specified amount but the measuring tank 13 has not yet reached the specified amount, the fine pulverizer 11 is stopped, and after the measuring tank 13 reaches the specified amount, the mixing tank 15 simultaneously Start preparation. Alternatively, when both the metering tanks 13 and 14 have reached the specified amount but the mixer 15 is still processing the previous batch, the coarse crusher, fine crusher and shifter are stopped. When the operation of the mixer is completed, the coffee particles inside are transferred to the product receiving tank 17, and when the inside becomes empty, the charging into the mixer 15 from the measuring tanks 13 and 14 is automatically started. Next, when the measuring tank is empty, the operations of the coarse pulverizer, the fine pulverizer and the shifter are automatically started.

(Examples 2 to 5 and Comparative Example 1) After roasting coffee beans, particles coarsely ground by a crushing type crusher to have a central particle size of 0.5 mm or more (Example 2), similarly. Particles finely ground to have a central particle diameter of 0.4 mm or less (Example 5), particles in which both were blended in 8: 2 (Example 3) and particles in which they were blended in 6: 4 (Example 4) were prepared. Prepared. Furthermore, for comparison, the central particle diameter is 0.5 mm on a roll mill.
Particles coarsely ground as described above (Comparative Example 1) were added, and the results of measuring the particle size distribution of these particles are shown in FIG.

The particle size distribution is measured by sieving a certain amount of particles into seven stages of openings 0.25, 0.3, 0.425, 0.5, 0.6, 0.85 and 1.0 mm and expressing them by weight% of each component.
For example, the weight percentage of particles having a particle size of 0.25 to 0.3 mm is shown as a component having a particle size of 0.25 mm.

From the figure, it can be seen that the particle size distribution of the particles crushed by the crushing method is much sharper than that of the particles crushed by the roll mill.

Next, in order to examine the taste and aroma of the coffee of Examples 2 to 5, a sensory test was conducted by 10 panelists. The taste and aroma of coffee were scored on a scale of 5 out of 5 items of aroma, sourness, bitterness, astringency and aroma without notifying the panelist of the sample.

Table 1 shows the average value and standard deviation of each person's evaluation. In addition, the color of the coffee liquid is shown by the light transmittance.

[0036]

[Table 1]

All of these evaluation items are important factors for the taste of coffee, but the richness and aroma are particularly important criteria. According to the results of the sensory test, in order to make coffee with excellent rich taste and aroma, and also other factors balanced, the particle size distribution should be 0.5 mm or more and 0.
It can be seen that it is necessary to blend so that it has at least one peak in the region of 4 mm or less.

[0038]

EFFECTS OF THE INVENTION The roasted coffee particles of the present invention do not have their surfaces ground, so that there is no emission of aroma generated by oxidation of fat and roasting, and the particle size distribution has a particle size of 0.
It is blended so that it has peaks in the region of 5 mm or more and 0.4 mm or less, and excellent coffee flavor and aroma, as well as coffee with a balanced sourness, bitterness and astringency can be obtained.

[Brief description of drawings]

FIG. 1 shows a conceptual diagram of a crushing mechanism of a crushing type crusher.

FIG. 2 shows a cross-sectional shape of a slit of a crushing roll of a crushing type crusher.

[Explanation of symbols]

1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b Pair of crushing rolls 1c, 2c, 3c, 4c Slits of crushing rolls 5 Raw material supply port of crusher 6 Crushed particle extraction port 7, 7 ', 7 "crushing Saw-tooth crests on the roll 8 Saw-tooth troughs on the milling roll 9,9 'Coffee particles

[Figure 3] Coffee roasted after roasting with a crusher
Scanning electron micrograph (× 40) showing the structure of particles
is there.

[Fig. 4] Coffee roasted after roasting with a crusher
Scanning electron micrograph (80x) showing the structure of particles
is there.

[Fig. 5] Coffee grains coarsely ground by a roll mill after roasting
It is a scanning electron micrograph (40 times) showing the structure of the offspring.
It

[Fig. 6] Coffee grains coarsely ground by a roll mill after roasting
It is a scanning electron micrograph (80 times) showing the structure of the offspring.
It

[Figure 7] Coffee grains finely ground with a roll mill after roasting
It is a scanning electron micrograph (80 times) showing the structure of the offspring.
It

FIG. 8: Coffee grains finely ground with a roll mill after roasting
Scanning electron micrograph (× 120) showing the structure of the offspring
is there.

FIG. 9 shows a flow sheet of the production system and control system of the present invention.

[Explanation of symbols]

 10 Coarse crusher (cracking type) 11 Fine crusher (cracking type) 12 Shifter 13 Coarse particle measuring tank 14 Fine particle measuring tank 15 Mixer 16 Controller 17 Product receiving tank

FIG. 10 is a chart showing the particle size distribution of coffee particles.

[Explanation of symbols]

 18 Particle size distribution of coffee particles of Example 2 19 Particle size distribution of coffee particles of Example 3 20 Particle size distribution of coffee particles of Example 4 21 Particle size distribution of coffee particles of Example 5 22 Particle size distribution of coffee particles of Comparative Example 1

Claims (3)

[Claims] 1. Roasted coffee beans, which are then crushed by a crusher type crusher, and the particle size distribution is such that the particle size is 0.
Roasted coffee particles having at least one peak in a region of 5 mm or more and 0.4 mm or less. 2. After roasting coffee beans and crushing by a crushing type crusher to prepare at least two kinds of particles having different central particle diameters, they are mixed to have a particle size distribution of particle diameters.
A method for producing roasted coffee particles, which comprises blending so as to have at least one peak in a region of 0.5 mm or more and 0.4 mm or less. 3. The crushing grinder 10 and 11, the shifter 12, the measuring tanks 13 and 14, the mixer 15 and the control device 16, after roughly roasting the roasted coffee beans with the crushing grinder 10. The coarse crushed particles from which the coffee beans have been removed by the shifter 12 and the dust are weighed in a fixed amount in the measuring tank 13, and a part of the coarse crushed particles is further finely crushed in the crushing type crusher 11 and then in the measuring tank 14. Weigh the coarsely crushed particles so that they have a certain ratio, and mix them with a mixer.
The mixture is mixed in 15 to prepare coffee particles, and the control device 16 controls the optimum on / off of the whole system consisting of a continuous operation of a crushing crusher and shifter, a batch operation of a measuring tank and a mixer. An apparatus for producing roasted coffee particles, characterized by controlling and controlling so that a mixing ratio of coarsely pulverized particles and finely pulverized particles is always constant.