JP2003274862A - Method for low-oxygen roasting of coffee bean and method for producing low-oxygen roasted coffee bean - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably producing low-oxygen roasted coffee beans in view of the problems that conventionally, deep roasting of coffee beans intensifies the flavor and affords products of coffee feeling when blended with cow milk and/or other materials, however, due to deep roasting practices, unfavorable flavors such as unpleasant bitterness may be developed. <P>SOLUTION: A roasting method for obtaining deep-roasted coffee beans comprises the following practice. Coffee beans are allowed to flow in an oxygen- free or a low-oxygen atmosphere with its temperature controlled to 100-250°C, preferably 150-200°C, the ambient temperature is then raised at a rate of 5-50°C/min, preferably 10-30°C/min, and the coffee beans are roasted for 3-15 min. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of roasting deeply roasted coffee beans that is easy to drink, has a mild aftertaste, and retains the bitterness peculiar to coffee, and a low oxygen roasting method through the roasting process. The present invention relates to a manufacturing method for manufacturing roasted coffee.

[0002]

2. Description of the Related Art Conventionally, as a method for roasting coffee beans, in addition to roasting treatment with hot air, burner heating with a rotary pot, far-infrared ray, or Japanese Patent Laid-Open No. 1-256347, "Roasting Coffee Beans". As disclosed, efficient roasting methods using superheated steam have become known.

As a means for improving the roasting method of coffee beans, Japanese Patent Laid-Open No. 30754/1994 "Roasting method of coffee beans" discloses that when roasting coffee beans while flowing them with superheated steam, By reducing the flow rate from the start of roasting to the end of roasting, the roasting efficiency is improved, and roasted coffee beans of good quality without uneven roasting can be obtained.

A means for easily and surely preventing an increase in the sourness of an extract of a roasted product while making the most of the merit of the roasting method of coffee beans by superheated steam such as improving the extraction efficiency of roasted products and improving the quality such as aroma. As disclosed in Japanese Patent Laid-Open No. 2001-149013, "roasting coffee beans" is a method of roasting coffee beans in which roasted coffee beans are heated using superheated steam, in which the coffee beans are preheated before the roasting. A featured roasted coffee bean method is disclosed.

[0005]

It is known to obtain roasted coffee beans of good quality without uneven roasting by using the method of roasting coffee beans as described above, but roasting coffee beans deeply Regarding that, by doing so, the flavor becomes stronger, and even if it is mixed with milk or other ingredients, a product with a coffee feeling can be obtained, but depending on this means of deep roasting, unpleasant bitterness etc. are not preferable. It often has a flavor, and requires improvements in green coffee beans, roasting machines, and roasting methods, but no definitive improvement method has been known so far.

Further, since the roasting atmosphere cannot be controlled to an oxygen-free atmosphere or a low-oxygen atmosphere, there is no means for preventing the oxidation of the finished coffee beans.

[0007]

Means for Solving the Problems The present inventors have found that when roasting under an oxygen-free atmosphere or a low oxygen atmosphere in a part of the roasting process and under a specific temperature condition, it is easy to drink and has an aftertaste. It was found that a deep roasted coffee bean having a good mild flavor and bitterness was obtained, and the roasting method for coffee beans and the method for producing low oxygen roasted coffee beans according to the present invention could be provided.

That is, the first aspect of the present invention is that the roasting environment atmosphere is an oxygen-free or low-oxygen atmosphere and the atmosphere temperature is 100.
To 250 ° C., preferably 150 to 200 ° C., the coffee beans are allowed to flow under an atmosphere, and the atmosphere is further heated at a rate of 5 to 50 ° C., preferably 10 to 30 ° C./min, to 3 to 3 ° C. It is a method for roasting coffee beans, which comprises roasting for 15 minutes.

A second aspect of the present invention is that the roasting environment atmosphere is
2. The roasting method for coffee beans according to claim 1, wherein the atmosphere is oxygen-free or low-oxygen atmosphere in which air is replaced with an inert gas selected from nitrogen or carbon dioxide or superheated steam.

[0010] Coffee beans are allowed to flow under an atmosphere in which the roasting environment is oxygen-free or low-oxygen and the atmosphere temperature is controlled to 100 to 250 ° C, preferably 150 to 200 ° C, and the atmosphere is adjusted to 5 to 50 ° C. C., preferably at a rate of 10 to 30.degree. C./min, the first step of roasting the coffee beans for 3 to 15 minutes, and then gas while cooling in an oxygen-free or low oxygen concentration atmosphere. It is characterized by comprising a second step of degassing and a third step of crushing the obtained roasted beans in an oxygen-free or low oxygen concentration atmosphere, degassing if necessary, and bagging. A method for producing low oxygen roasted coffee beans.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The superheated steam tester (not shown) of the present invention is basically operated under a roasting environment atmosphere in which the oxygen concentration is low, and an inert gas ( Nitrogen, carbon dioxide, etc.) or superheated steam is used to replace the air in the tester to perform the overheat treatment of the work piece.

In this case, the roasting environment atmosphere is oxygen-free or low-oxygen atmosphere, and the atmosphere temperature is 100 to 250 ° C.
Preferably, the coffee beans are allowed to flow under an atmosphere controlled at 150 to 200 ° C., and the atmosphere is kept at 5 to 50 ° C.
C./min., Preferably 10 to 30.degree. C./min.

Further, low oxygen roasted coffee beans are produced using the apparatus as described above. In the production method of the present invention, the roasting environment atmosphere is oxygen-free or low oxygen atmosphere and the ambient temperature is 100. ~ 250 ° C, preferably 150-200 ° C
Flow coffee beans under controlled atmosphere,
The temperature of the atmosphere is raised at a rate of 5 to 50 ° C., preferably 10 to 30 ° C./min, and the coffee beans are heated to 3 to 15 ° C.
A first step of roasting for a minute, and then a second step of degassing while cooling in an oxygen-free or low oxygen concentration atmosphere,
Through the third step of crushing the obtained roasted beans in an oxygen-free or low-oxygen concentration atmosphere, degassing if necessary, and bagging, the desired low-oxygen roasted coffee beans can be produced. I can.

[0014]

Example 1 Using a superheated steam tester (not shown), Brazilian coffee beans and Colombian coffee beans,

[0011] and

According to the above, roasted beans obtained by deep roasting (full city) for 10 minutes in an oxygen-free atmosphere and 10 minutes deep roasting (full city) using a conventional small drum roaster. As a comparative example, two types were obtained.

The roasted beans thus obtained were allowed to stand at room temperature for 9 days, and then 24 g of ground coffee beans were leached with 300 g of hot water for 5 minutes and filtered to obtain an extract. The acidity and pH of these solutions were determined.
Values and Lab values were measured, and the results are shown in Table 1.

[0016]

[Table 1]

In this case, the acidity is represented by the alkali consumption,
The amount (ml) of 0.1N NaOH aqueous solution used to neutralize 100 g of coffee liquor (pH 8.20) is shown, but as shown in Table 1, compared with the acidity of the conventional method as the control group. It was found that both the Brazilian coffee beans and the Colombian coffee beans obtained by the method of the present invention had a decreased acidity and an increased pH value.

As a result, it is shown that the oxygen-free roasting of the present invention decomposes the acid of coffee well even with the same roasting time.

Similarly, the Lab value of the extract was measured using a color difference meter. In this case, L indicates the black and white degree of the liquid, a indicates the red degree, and b indicates the yellow degree. , The ratio of the a value when the L value was set to the reference value of 1 was higher in the oxygen-free roasting group than in the control group, indicating that the color balance of the liquid was different.

Regarding the flavor of coffee, particularly sweetness, bitterness, and aftertaste, it is considered to be related to the structure of the brown substance, which is the origin of the liquid color, and the difference in the balance of the liquid colors has the following flavors. It is considered to be a factor explaining the difference.

A sensory test was conducted using the extract obtained from the roasted beans on the 9th day after roasting. In this case, 6 tastings were conducted 3 times, and the results (average values) are shown in Table 2. , It was found that the flavor, aftertaste and sourness were excellent when the control group was used as a reference. That is, it was a mild coffee with little sourness and little aftertaste.

[0022]

[Table 2] * Each item was evaluated as ± 3 points, with the control group being 0. * Regarding flavor and aftertaste, the good quality direction was +, and the bad direction was −. Regarding sourness, the strong direction was +, and the weak direction was −.

[0023]

The roasted beans produced by the method of the present invention are
Since the roasting environment is roasted under conditions of low oxygen concentration and specific temperature, flavor is improved compared to conventional products, and mild coffee with less sourness and less aftertaste is obtained. I was able to.

Further, after roasting is finished, the product is immediately cooled in an atmosphere with a low oxygen concentration, and then, under the same conditions, aging (gas removal), pulverization, and filling into a bag or the like to further deteriorate quality such as oxidation. It is possible to obtain less coffee beans and powder.

Claims (3)

[Claims] 1. Coffee beans are flown under an atmosphere in which the roasting environment is oxygen-free or low-oxygen and the atmosphere temperature is controlled to 100 to 250 ° C., preferably 150 to 200 ° C., and the atmosphere is further changed. The temperature is raised at a rate of 5 to 50 ° C / minute, preferably 10 to 30 ° C / minute,
A method for roasting coffee beans, which comprises roasting for 3 to 15 minutes. 2. The roasting environment atmosphere is an oxygen-free or low-oxygen atmosphere in which air is replaced with an inert gas selected from nitrogen or carbon dioxide gas or superheated steam. The method for roasting coffee beans according to 1. 3. Coffee beans are flown under an atmosphere in which the roasting environment is oxygen-free or low-oxygen and the atmosphere temperature is controlled to 100 to 250 ° C., preferably 150 to 200 ° C., and the atmosphere is set to 5 The first step of roasting the coffee beans for 3 to 15 minutes by raising the temperature at a rate of -50 ° C / min, preferably 10 to 30 ° C / min, and then under anoxic or low oxygen concentration atmosphere The second step of degassing while cooling, the roasted beans obtained are crushed in an oxygen-free or low oxygen concentration atmosphere, if necessary degassing,
A method for producing low-oxygen roasted coffee beans, which comprises a third step of bagging.