JPH06209708A - Method for roasting coffee bean and method for producing coffee extract solution from the roasted coffee bean - Google Patents

Abstract

PURPOSE:To readily provide a coffee having the original flavor and taste of the coffee to the utmost by roasting coffee beans in the contact state of the coffee beans with amorphous beads, grinding the roasted mixture and subsequently extracting the ground mixture. CONSTITUTION:Rigid glass beads each having a diameter of 1.3mm are charged in a 5l rotary oven, rotated at 25r.p.m, and simultaneously heated at 220 deg.C. Coffee beans are charged into the rotary oven, rotate together with the glass beans at 220 deg.C, and simultaneously roasted. The roasted coffee beans are frozen at -90 deg.C in a freezing machine, and subsequently ground with a grinding machine into 20-28 mesh. The ground coffee beans are extracted with 90 deg.C hot water to provide a coffee having the original flavor and taste of the coffee beans to the utmost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for roasting coffee beans which can obtain coffee having the maximum aroma and flavor of coffee beans, and a coffee extract using the obtained roasted coffee beans. Regarding manufacturing method.

[0002]

2. Description of the Related Art Generally, a coffee extract is produced by roasting green coffee beans, crushing them, and extracting them with hot water. Conventionally, coffee beans are generally roasted by sending the heat generated from a heat source into a rotary roaster that contains green coffee beans. Since the generated air only passes through the gaps between the coffee beans, it has a low thermal conductivity and takes a long time of about 15 to 20 minutes for roasting. So 240
If the roasting temperature is raised to about 250 ° C. and the time is shortened, only the surface of the coffee beans will be burnt and the inside will not be roasted uniformly. Therefore, the roasted coffee beans obtained do not have a sufficient aroma, and astringency and bitterness occur on the burnt bean surface.

Therefore, various methods for roasting coffee beans uniformly in a shorter time have been studied. For example, a method has been proposed in which ceramic particles are mixed with coffee beans and roasted in a mixed state (JP-A-1-206954). In this method, the ceramic particles and coffee beans are brought into contact with each other and heated together so that far infrared rays generated from the ceramic particles are transmitted into the coffee beans to perform roasting. Other than that,
A method has also been proposed in which coffee beans and ground stones are mixed and the mixture is heated and roasted (JP-A-2-227032). This method utilizes a so-called “stone-baked potato” manufacturing method, in which a roasting machine is filled with crushed stones, coffee beans are mixed therein, and roasting is performed while heating and stirring. In any of the above roasting methods, the ceramic particles or crushed stones that are heat conductors can retain the heat generated by heating and quickly transfer the heat from the periphery of the coffee beans to the inside. The roasting time can be shortened as compared with a roasting method in which high temperature air only passes over the bean surface, and the inside of coffee beans can be roasted uniformly.

However, the ceramic particles and the crushed stone contain inorganic substances such as magnesium, iron, calcium, manganese, aluminum and silicon. Therefore, when the ceramic particles or the heat conductor of the crushed stone and the coffee beans are brought into contact with each other under heating, the above-mentioned minerals contained in the ceramic particles or the crushed stone are transferred to the coffee beans. The extract obtained from the beans has an alkaline or salty taste due to the inorganic substance, which impairs the flavor of the coffee extract. Further, both the ceramic particles and the crushed stone are porous. Therefore, during roasting, the oil component and the soybean meal contained in the coffee beans in an amount of about 15% by weight enter into the holes and adhere. The once adhered oil component and soybean meal cannot be completely removed even after washing the used ceramic particles and crushed stones, and remain and deteriorate with time. Therefore, when roasting is repeated many times using the same ceramic particles and crushed stones, in addition to deterioration over time, the deteriorated odor of oil and soybean meal caused by heating during roasting is adsorbed on coffee beans. , The scent of coffee extract is significantly impaired.

Also, since the good scent of roasted coffee beans is mostly volatile, in the crushing process of coffee beans after roasting, the scent is greatly scattered due to frictional heat, etc. The coffee extract obtained has a reduced aroma.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to obtain coffee having a sufficient aroma and flavor derived from coffee beans. To provide a method for roasting coffee beans and a method for producing a coffee extract using the obtained roasted coffee beans.

[0007] The above-mentioned object is a roasting method for coffee beans, characterized in that, when roasting coffee beans, roasting is carried out in a state where the amorphous granules and coffee beans are in contact with each other, and According to a method for producing a coffee extract characterized in that coffee beans roasted in a state where the coffee beans and the amorphous granules are brought into contact with each other are frozen and ground, and extraction is carried out using the ground coffee beans. To be achieved.

That is, the present inventors have confirmed that the components contained in the heat conductor are not transferred to coffee beans by heating during roasting, and that the oil components and bean dregs in the coffee beans are taken into the tissue. A heat conductor which is free of cleaning and which can be thoroughly washed after use and which can be repeatedly used was examined. As a result, they have found that good results can be obtained by using an amorphous granular material as the heat conductor. In addition, the inventors of the present invention, when producing a coffee extract, freeze the roasted coffee beans that have been roasted in contact with the amorphous granules, and pulverize in a state of confining the aroma. When,
The present inventors have found that the aroma extracted during roasting is transferred to a coffee extract without scattering, and the present invention has been completed.

Next, the present invention will be described in detail. The coffee beans used in the present invention are not particularly limited as long as they are commonly used coffee beans. Moreover, you may use suitably the thing which made sugar and spice adhere to the surface of coffee beans as needed.

Next, a glass body is preferably used as the amorphous substance used for roasting. As the material of the glass body, ena glass, telex glass, when using a material having excellent heat resistance such as borosilicate glass or hard glass such as Pyrex glass, there is no deformation or melting due to heating during roasting, and also during stirring. It is also suitable because it has impact resistance during washing and cleaning.

Further, it is desirable that the shape is a granular body such as a sphere, an egg or a disc. That is, if there is a sharp edge, it will damage the coffee beans when they come into contact,
This is because the charcoal excessively burns from the scratched portion, so that the coffee extract is likely to have an unpleasant taste such as bitterness and astringency.

Further, it is preferable to use those having a diameter of less than 3 mm. If it exceeds 3 mm, the contact area between the amorphous granules and the surface of the green coffee beans becomes small, so that it becomes difficult to sufficiently surround the periphery of the coffee beans, and the coffee beans and the amorphous granules are separated and uniform. Roasting tends to be impossible. Also, when stirred with coffee beans, the beans are easily damaged.

The roasting step using the coffee beans and the amorphous granules is performed as follows, for example. That is, first, the amorphous granular material is put into a roasting machine and preferably heated to about 210 to 230 ° C. Next, green coffee beans are put into this state, and brought into contact with the amorphous granular material. The contact state may be a state in which the coffee beans are in contact with each other by being mixed so that the periphery of each coffee bean is surrounded by the amorphous granules. Alternatively, the layer of coffee beans may be a layer of the amorphous granules. It may be in a contact state by being surrounded. The amount of the amorphous granules is preferably 6 times or more, more preferably 10 to 30 times the amount of coffee beans, and the whole coffee beans can be roasted uniformly in a short time, which is preferable. .

The roasting temperature and time may be appropriately set according to the type of coffee beans used and the type of coffee product using the obtained coffee extract. As the roasting means, a drum type rotary roaster, a non-rotating roaster or the like commonly used or a frying pan may be used. Further, as the material of the roasting machine, it is preferable to use stainless steel rather than aluminum or copper, during roasting, it is possible to suppress the transfer of the inorganic substances contained in the wall of the roaster to the coffee beans, It is suitable.

The roasting may be performed in a stationary state or while rotating or stirring by using a rotary pot or the like. In particular, in order to make the degree of roasting uniform, the roasting may be performed while rotating or stirring. It is preferable to perform roasting. Further, the roasting step may be either an open system or a closed system, but a closed system or a system close to it is preferable in view of preventing excessive scattering of the aroma of coffee beans. The coffee beans thus obtained, without the components of the heat conductor transferred to the coffee beans,
Further, no matter how many times the same heat conductor is used, stable and good roasting can be performed.

Next, a method for producing a coffee extract using the roasted coffee beans obtained as described above is preferably carried out, for example, as follows. That is, first,
Freeze roasted coffee beans. At this time, the roasted coffee beans are frozen to a temperature of preferably -10 to -20 ° C, more preferably -100 to -80 ° C. -11
When the temperature is lower than 0 ° C, even if hot water of 90 to 95 ° C is poured at the time of extraction, the temperature drops sharply when the hot water passes through the frozen ground coffee beans. As a result, the soluble solid content in coffee beans tends to be insufficiently extracted. Conversely-
If the temperature is higher than 20 ° C., it tends to be impossible to sufficiently prevent the scent from being scattered during pulverization.

Examples of the freezing medium include liquid nitrogen, dry ice or dry ice and alcohol, air and the like. Among them, it is particularly preferable to use cooling air because the freezing medium itself has no odor and the temperature can be easily set and managed. When the roasted coffee beans are frozen, they may be frozen immediately after roasting, but it is more preferable to cool the roasted coffee beans to a room temperature range in advance.

Subsequently, the frozen roasted coffee beans are ground with a grinder. At this time, the grain size of coffee beans is 10 to 3
It is preferable to grind so as to have a size of 2 mesh because clogging is reduced during filtration and extraction.

Next, 90 to 95 of ground coffee beans
Pour hot water at ℃ and extract. At this time, if necessary, in the hot water, a pH adjuster, sugar, dairy product, emulsifier,
Stabilizers and the like may be added.

A coffee extract can be obtained by appropriately filtering the mixed liquid which has been subjected to the above treatment. This coffee extract may be used as it is, or may be concentrated or seasoned.
Alternatively, it may be filled in a sealed container such as a bottle or a can and sterilized to obtain a drink that can be distributed for a long period of time. The coffee extract thus obtained has a good aroma and flavor because ground coffee beans retain the aroma. In addition, the coffee extract obtained as described above has a good aroma retaining effect even when subjected to high temperature sterilization.

[0021]

As described above, according to the present invention, in the roasting step, the amorphous granular material is used as the heat conductor, and the roasting is carried out in the state of being brought into contact with the coffee beans. Therefore, since the amorphous granules retain the heat generated by heating and quickly conduct the heat to the inside of the coffee beans, it is possible to roast uniformly in a short time. Furthermore, the amorphous granular material does not transfer its contained components to coffee beans even when they are brought into contact with coffee beans under heating. Moreover, since the amorphous granular material has a smooth surface and does not have a porous structure, the oil component and the soybean meal in coffee beans are not taken into the structure of the amorphous granular material. Even if the oil component of coffee beans or soybean meal adheres to the surface, it can be easily and completely removed by regular cleaning, and the quality of coffee beans is stable even after repeated use. . Therefore, by undergoing the roasting step of the present invention, the coffee beans are roasted evenly to the inside in a short time, and the good aroma and taste are maximized.

Further, by roasting roasted coffee beans prior to crushing and crushing while suppressing an increase in temperature due to frictional heat during crushing, the scent extracted in the roasting process should be scattered during crushing. Not retained and transferred to coffee extract. As a result, it is possible to obtain a coffee extract in which the aroma of coffee beans is maximized. Further, according to the present invention, even when low-quality coffee beans such as Robusta species are used, the aroma can be maximized, and a coffee extract having an excellent aroma and taste can be obtained.

Next, the present invention will be specifically described with reference to examples. (Example 1) <Roasting step> 3000 parts by weight of hard glass beads (substantially spherical) having a diameter of 1.3 mm (hereinafter referred to as "part") were put into a rotary pot having a volume of 5 l, and the mixture was heated to 25 r. p. 2 while rotating with m
Heated to 20 ° C. To this, 240 parts of green coffee beans (Colombia) were added and roasted while rotating at the above temperature while rotating with glass beads to obtain roasted coffee beans having an L value of 25. The glass beads were used after being roasted under the above conditions 15 times in advance and then lightly washed with water. At this time, the amount of glass beads was 12.5 times the amount of coffee beans.

<Pulverizing Step> Next, the roasted coffee beans were pulverized by a pulverizer into 20 to 28 mesh. <Extraction step> To the crushed coffee beans, 5600 parts of hot water at 90 ° C was poured to obtain a coffee extract.

Comparative Example 1 A coffee extract was obtained in the same roasting step as in Example 1, except that glass beads were not used and roasting was performed with hot air at 220 ° C.

Regarding the time required for roasting coffee beans, the presence or absence of coffee bean deteriorating odor, and the aroma and taste of the coffee extract obtained using each coffee bean in Example 1 and Comparative Example 1 described above, 20 specialized panelists were asked. The sensory evaluation was performed. The results are shown in Table 1.

[0027]

[Table 1]

From the results shown in Table 1, in Example 1, an extract having a high scent derived from the original scent of coffee beans was obtained,
Furthermore, there were no miscellaneous tastes such as bitterness and astringency. Further, although the glass beads had already been used 15 times, the deterioration odor due to the grounds and oil and fat components of coffee beans did not transfer to the beans. On the other hand, in Comparative Example 1, since roasting with hot air is performed, it is necessary to spend more than twice as long as in Example as roasting, and the obtained coffee extract has a weak aroma. , I felt bitterness and astringency.

(Example 2) <Roasting step> 3000 parts of hard glass beads (substantially spherical) having a diameter of 1.3 mm were put in a rotary pot having a volume of 5 l, and 25
r. p. It was heated to 220 ° C. while rotating at m. Here, 240 parts of green coffee beans (Colombia) are added,
Roasting was performed while maintaining the above temperature while rotating with glass beads to obtain roasted coffee beans having an L value of 25. The glass beads were used after being roasted under the above conditions 15 times in advance and then lightly washed with water. Also, at this time,
The amount of glass beads was 12.5 times the amount of coffee beans.

<Freezing Step> The roasted coffee beans are cooled to 30 ° C. by blowing air at room temperature, and then the cooled coffee beans are placed in a refrigerator (Neocool manufactured by Yamato Co., Ltd.) Frozen at 90 ° C. <Pulverizing Step> Next, the frozen coffee beans were pulverized by a pulverizer so as to have a size of 20 to 28 mesh. <Extraction step> To the crushed coffee beans, 5600 parts of hot water at 90 ° C was poured to obtain a coffee extract.

(Example 3) Roasted coffee beans were obtained in the same manner as in Example 2 except that the amount of glass beads was 6 times the amount of coffee beans in the roasting step, and further a coffee extract was obtained. .

(Example 4) Roasted coffee beans were obtained in the same manner as in Example 2 except that the amount of glass beads was 25 times the amount of coffee beans in the roasting step, and further a coffee extract was obtained. .

(Comparative Example 2) A coffee extract was obtained in the same manner as in Example 2 except that ceramic fragments (0.3 to 2 mm in size) were used in place of the glass beads in the roasting process.
The ceramic pieces were prepared by repeating the roasting conditions of Example 2 15 times in advance and then lightly washing with water.

(Comparative Example 3) A coffee extract was obtained in the same manner as in Example 2 except that sea sand (10 to 25 mesh) was used instead of glass beads in the roasting step. The ceramic pieces were prepared by repeating the roasting conditions of Example 2 15 times in advance and then lightly washing with water.

The time required for roasting coffee beans, the presence or absence of coffee bean deteriorating odor, and the aroma and taste of the coffee extract obtained using each coffee bean in Examples 2 to 4 and Comparative Examples 2 and 3 were as follows: Sensory evaluation was performed by 20 professional panelists. The results are shown in Table 2.

[0036]

[Table 2]

From the results shown in Table 2, in the examples, a highly scented extract in which a good aroma inherent in coffee beans was extracted was obtained, and further, there were no miscellaneous tastes such as bitterness and astringency, and the aroma and taste were good Became. Further, although the glass beads had already been used 15 times, the deterioration odor caused by the grounds and oil and fat components of coffee beans did not transfer to the beans. In particular, in Examples 2 and 4, the scent of scent (strength) was observed in the coffee extract.
Was very good, and the taste was also refreshing, and good results were obtained.

On the other hand, in Comparative Example 2, as the heat conductor, 1
Since the ceramic pieces that were used 5 times were used, the deteriorated odor of the coffee bean meal and oil and fat remaining in the holes of the ceramic pieces was transferred to the coffee beans. Furthermore, the smell of deterioration was also felt in the coffee extract. In addition, since the inorganic substances in the ceramic pieces were transferred to coffee beans, the coffee extract had a salty taste. In Comparative Example 3, the heat conductor is already 15
The same results as in Comparative Example 2 were obtained because the sea sand used again was used.

(Example 5) In the freezing step, roasted coffee beans were immersed in liquid nitrogen and rapidly cooled to -150 ° C.
A coffee extract was obtained in the same manner as in Example 2 except that the coffee extract was frozen.

(Example 6) In the freezing step, a coffee extract was obtained in the same manner as in Example 2 except that air at room temperature was blown and the roasted coffee beans were rapidly cooled to -5 ° C and frozen.

As described above, regarding the time required for roasting coffee beans, the presence or absence of coffee bean deteriorating odor, and the aroma and taste of the coffee extract obtained using each coffee bean in Examples 5 and 6, 20 specialized panelists Sensory evaluation was performed. The results are shown in Table 3.

[0042]

[Table 3]

From the results shown in Table 3, a highly scented extract was obtained in which the original good scent of coffee beans was extracted, and there was no bitterness such as bitterness or astringency.

Claims (2)

[Claims] 1. A method of roasting coffee beans, which comprises roasting the coffee beans in a state where the amorphous granules and the coffee beans are in contact with each other when roasting the coffee beans. 2. Coffee characterized in that coffee beans roasted in a state where the coffee beans and the amorphous granules are brought into contact with each other are frozen and crushed, and extraction is carried out using the crushed coffee beans. Extraction process.