Production method of coffee roasted beans, coffee roasted beans and coffee extract

Abstract

To provide a production method of coffee roasted beans capable of suppressing poor appearance caused by turbidity after warming and preservation, and acquiring a coffee extract in which a coffee derived flavor and concentration are maintained.SOLUTION: There is provided a production method of coffee roasted beans comprising: a step for processing coffee raw beans so that volume percentage increase of the coffee raw beans becomes 32.0 to 41.0%; and a step for roasting the processed coffee raw beans.

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method for producing roasted coffee beans, roasted coffee beans, and a coffee extract. [Background technology]

[0002] It has been known that coffee extracts become cloudy due to deterioration over time when heated. In recent years, when bottled coffee drinks that can be stored at elevated temperatures have become popular, the poor appearance caused by cloudiness has become an issue for some products.

[0003] As a method for suppressing turbidity in coffee extract, for example, a method of adding enzymes such as cellulase and galactomannanase is known (for example, Patent Document 1). However, this method is likely to cause other problems, such as the loss of coffee-derived aroma and flavor due to the enzyme reaction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-272375 A Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an object of an embodiment of the present invention is to provide a method for producing roasted coffee beans that can suppress appearance defects due to turbidity after heated storage and can provide a coffee extract that maintains the coffee-derived aroma and concentration.Another embodiment of the present invention is to provide roasted coffee beans that can suppress appearance defects due to turbidity after heated storage and can provide a coffee extract that maintains the coffee-derived aroma and concentration.Another embodiment of the present invention is to provide a coffee extract that suppresses appearance defects due to turbidity after heated storage and can provide a coffee extract that maintains the coffee-derived aroma and concentration. [Means for solving the problem]

[0006] The present invention includes the following embodiments, but is not limited to the following embodiments. (1) Processing green coffee beans so that the bulk increase rate is between 32.0 and 41.0%; and Roasting the treated green coffee beans. A method for producing roasted coffee beans, comprising: (2) The process is The coffee beans are soaked in water at a temperature between 0℃ and 40℃. Steam treatment of coffee beans that have been soaked in water The method for producing roasted coffee beans according to (1) above, (3) The method for producing roasted coffee beans according to (1) or (2) above, wherein the hardness of the roasted coffee beans after roasting is 3.0 to 4.0 kgf. (4) Roasted coffee beans obtained by the method for producing roasted coffee beans described in any one of (1) to (3) above. (5) A coffee extract obtained using the roasted coffee beans described in (4) above as a raw material. (6) A coffee extract according to the above item (5), in which the difference (A%-B%) between the transmittance B% for light with a wavelength of 660 nm after heating at 60°C for 14 days and the transmittance A% for light with a wavelength of 660 nm before heating is 1.0% or less. Effect of the Invention

[0007] According to an embodiment of the present invention, a method for producing roasted coffee beans can be provided that suppresses poor appearance due to turbidity after heated storage and allows for the production of a coffee extract that maintains the coffee-derived aroma and concentration. According to another embodiment of the present invention, roasted coffee beans can be provided that suppresses poor appearance due to turbidity after heated storage and allows for the production of a coffee extract that maintains the coffee-derived aroma and concentration. According to another embodiment of the present invention, a coffee extract can be provided that suppresses poor appearance due to turbidity after heated storage and allows for the production of a coffee extract that maintains the coffee-derived aroma and concentration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of the present invention will be described below, but the present invention is not limited to the following embodiment.

[0009] [How roasted coffee beans are manufactured] A method for producing roasted coffee beans that is an embodiment of the present invention includes treating green coffee beans so that the bulk increase rate is 32.0 to 41.0% (sometimes referred to herein as a "green bean treatment step"), and roasting the treated green coffee beans (sometimes referred to herein as a "roasting step"). The method for producing roasted coffee beans may further include any optional steps.

[0010] (Green bean processing process) In the green bean processing step, the green coffee beans are processed to increase their bulk (volume) and obtain green coffee beans having a bulk (volume) increase rate of 32.0 to 41.0% (volume %). There are no particular limitations on the type and origin of the green coffee beans used. Commercially available green coffee beans may be used as is in the green bean processing step. Examples of varieties include Arabica, Robusta, and Liberica. Examples of origins include Brazil, Colombia, Tanzania, Ethiopia, Mocha, Venezuela, Guatemala, Costa Rica, Blue Mountain, Kona, Mandheling, and Kilimanjaro. The green coffee beans may be green coffee beans consisting of a single type, or may be blended green coffee beans containing two or more types of green coffee beans.

[0011] The bulk increase rate can be calculated using the bulk A (mL) of the green coffee beans before treatment and the bulk B (mL) of the green coffee beans after treatment. The bulk of the green coffee beans can be measured using a measuring cylinder. The volume of the measuring cylinder is, for example, 500 mL. The bulk increase rate can be calculated from the bulk A and bulk B using the formula: bulk increase rate (%) = 100 x [(bulk B (mL) - bulk A (mL)) / bulk A (mL)]. The amount of green coffee beans to be measured need only be the same as the number of green coffee beans before treatment and after treatment. For example, the volume of a specific mass (i.e., a specific number) of green coffee beans is measured before treatment, and the volume of the same number of green coffee beans is measured after treatment. 100 green coffee beans before and after treatment are collected, and the bulk is measured, and this operation is performed three times to calculate the average value.

[0012] When the bulk increase rate is 32.0% or more, the effect of suppressing cloudiness in the coffee extract after warm storage is obtained. When the bulk increase rate is 41.0% or less, it is possible to maintain the coffee-derived flavor and concentration while suppressing cloudiness in the coffee extract after warm storage. The bulk increase rate is 32.0 to 41.0%, preferably 33.0 to 41.0%, and more preferably 34.0 to 40.0%.

[0013] When the mass of green coffee beans put into a 500 mL measuring cylinder is 150 g, the volume of the green coffee beans before treatment is preferably 150 to 300 mL, more preferably 180 to 270 mL, and even more preferably 210 to 250 mL. The volume of 150 g of green coffee beans after treatment is preferably 198 to 424 mL, more preferably 236 to 380 mL, and even more preferably 277 to 353 mL.

[0014] The treatment of the green coffee beans may involve soaking the green coffee beans in water to increase their volume. The temperature of the water may be 0 to 100°C. Methods for soaking the green coffee beans in water include, for example, soaking the green coffee beans in water, sprinkling the green coffee beans with water, spraying the green coffee beans with water, and treating the green coffee beans with steam. The temperatures of the water for soaking, the water for sprinkling, and the water for spraying are preferably 0 to 40°C, more preferably 10 to 35°C, and even more preferably 15 to 30°C. For sprinkling or spraying, a known sprinkler or sprayer can be used. The steam treatment may be performed under conditions of a relative humidity of 90 to 100% and a temperature of 90 to 150°C. For the steam treatment, a known steamer can be used. Commercially available steamers include, for example, the Tea Manufacturing Machine Type 2K, a microcomputer steamer, and a steamer (all manufactured by Kawasaki Kiko Co., Ltd.). It is speculated that when green coffee beans contain water, the hydrolysis reaction is accelerated, reducing the amount of substances that cause turbidity more than usual, thereby preventing turbidity in the coffee extract and preserving the coffee-derived aroma and concentration. However, the present invention is not limited to this speculation.

[0015] In a preferred embodiment, the green bean processing step includes soaking the green coffee beans in water at a temperature of 0 to 40°C, and then steam treating the water-soaked green coffee beans. In a more preferred embodiment, the green bean processing step includes sprinkling or spraying the green coffee beans with water at a temperature of 0 to 40°C, and then steam treating the water-soaked green coffee beans. The amount of water sprinkled or sprayed can be, for example, 100 to 2000 mL, 150 to 1500 mL, or 300 to 800 mL per 150 g of green coffee beans. The time for sprinkling or spraying can be, for example, 0.1 to 10 minutes, 0.2 to 8 minutes, or 0.3 to 5 minutes. The time for the water steam treatment can be, for example, 10 to 60 minutes or 10 to 90 minutes when the relative humidity is 90 to 100% and the temperature is 90 to 100°C.

[0016] (Roasting process) In the roasting step, green coffee beans with a bulk increase rate after treatment of 32.0 to 41.0% are roasted. The roasting method may be, for example, any of direct fire, hot air, and semi-hot air. The roasting degree is not particularly limited. The roasting degree may be any of light roast, medium roast, and dark roast. The roasting degree is classified into, for example, light, cinnamon, medium, high, city, full city, French, and Italian. A known coffee roaster can be used for roasting. Examples of commercially available coffee roasters include the shop roaster Probatino Type 2, Sample Roaster, and the large industrial roaster Neptune (all manufactured by Probat).

[0017] [Roasted coffee beans] The above-mentioned production method can obtain roasted coffee beans. When the roasted coffee beans obtained by the above-mentioned method are used as a raw material, a coffee extract can be obtained that is suppressed from having a poor appearance due to turbidity after heated storage and that maintains the flavor and concentration derived from coffee.

[0018] Roasted coffee beans obtained using green coffee beans with a bulk increase rate of 32.0 to 41.0% tend to be hard. The hardness of the roasted coffee beans is, for example, 3.0 to 4.0 kgf. In an embodiment of the present invention, the hardness of the roasted coffee beans is expressed by placing the roasted coffee beans on a stage so that the center cut (the depression in the central part) of the beans faces downward, applying a vertical load to the roasted coffee beans, and the load (kgf) at the time when the roasted coffee beans crack. The roasted beans used for the measurement may be roasted beans having an L* value of 19.5 to 20.5 in the L*a*b* color system in a crushed state. The load can be measured using a digital force gauge attached to an electric test stand. For example, the high-performance type digital force gauge ZTA series can be used as the digital force gauge, and the electric test stand MX2 series (both manufactured by IMADA Co., Ltd.) can be used.

[0019] When the hardness of the roasted coffee beans is 3.0 kgf or more, the cleanliness (absence of unpleasant flavors) of the coffee extract tends to be improved. When the hardness of the roasted coffee beans is 4.0 kgf or less, the coffee extract tends to have a sufficient bitterness derived from coffee. The hardness is preferably 3.2 to 3.8 kgf, more preferably 3.5 to 3.7 kgf.

[0020] [Coffee extract] A coffee extract can be obtained by using the roasted coffee beans as a raw material. By using the roasted coffee beans as a raw material, the coffee extract is prevented from having poor appearance due to turbidity after heated storage, and the coffee-derived flavor is maintained. The coffee extract contains coffee-derived components extracted from ground coffee beans and an extraction solvent. The extraction solvent is generally water (0 to 100°C). The coffee extract can be obtained by a production method including grinding the roasted coffee beans to obtain ground coffee beans (sometimes referred to as a "grinding step" in this specification), and extracting coffee-derived components from the ground coffee beans (sometimes referred to as an "extraction step" in this specification).

[0021] (Crushing process) For the grinding, for example, a grinding machine of a roll grinder type, a flat cutter type, a conical cutter type, a blade cutter type, etc. can be used. The particle size of the ground coffee beans is classified into, for example, coarse grind, medium grind, medium-fine grind, fine grind, and ultrafine powder. For the grinding, for example, a grinding machine of a roll grinder type, a flat cutter type, a conical cutter type, a blade cutter type, etc. can be used.

[0022] (extraction process) Methods for extracting coffee-derived components include French press, aeropress, boiling, espresso, percolator, siphon, drip (paper, flannel, etc.), etc. Extraction may be performed in any of batch, semi-batch, and continuous modes.

[0023] The pH of the coffee extract is preferably 6.0 to 7.0, more preferably 6.2 to 6.8, and even more preferably 6.3 to 6.7. When the pH is within the above range, aggregation of coffee-derived components can be suppressed. In addition, the flavor of the beverage also tends to be good. The pH may be measured using a coffee extract at room temperature (about 25°C). For the measurement, a pH meter (for example, "Desktop pH Meter F-72" manufactured by Horiba, Ltd.) can be used.

[0024] If necessary, the pH of the coffee extract may be adjusted by adding a pH adjuster. Examples of pH adjusters include organic acids such as citric acid, malic acid, tartaric acid, acetic acid, lactic acid, phytic acid, and gluconic acid; alkali salts thereof; and alkali metal salts such as sodium bicarbonate (sodium hydrogen carbonate) and potassium carbonate. The pH adjusters may be added alone or in combination of two or more.

[0025] The Brix value of the coffee extract is preferably 1.00 to 10.0, more preferably 1.00 to 7.50, and even more preferably 1.00 to 5.00. When the Brix value is within the above range, aggregation of coffee-derived components can be suppressed. In addition, the flavor of the beverage tends to be good. The Brix value may be measured using a coffee extract at room temperature (about 25°C). A digital refractometer (for example, "RX-5000" manufactured by Atago Co., Ltd.) can be used for the measurement.

[0026] Coffee extracts are unlikely to have a lower transmittance due to storage at elevated temperatures. For example, when a coffee extract is heated in an atmosphere at 60° C. for 14 days, the difference in transmittance for light with a wavelength of 660 nm before and after heating (transmittance A before heating minus transmittance B after heating) is preferably 1.0% or less. The difference in transmittance is more preferably 0.8% or less, and even more preferably 0.5% or less. The transmittance may be measured using coffee extract at room temperature (about 25° C.). For the measurement, an ultraviolet-visible spectrophotometer (for example, Shimadzu Corporation's "UV-1800", optical path length 10 mm) can be used.

[0027] (container) Coffee extracts are usually provided as packaged coffee beverages in a container. Examples of containers include PET bottles, cans (aluminum, steel), paper, plastic, retort pouches, bottles (glass), etc. Considering heat resistance to retort sterilization treatment, hot sales, etc., cans (aluminum, steel) or reinforced plastic containers having a reinforcing layer, oxygen absorbing layer, etc. are preferred.

[0028] (sterilization) When the coffee extract is provided as a packaged coffee beverage, it is preferable to subject the coffee extract to a sterilization treatment after packaging in a container. The sterilization treatment can be carried out under sterilization conditions stipulated in the Food Sanitation Act. Examples of the sterilization method include UHT sterilization and retort sterilization. EXAMPLES

[0029] The embodiments of the present invention will be described with reference to the following examples, but the embodiments of the present invention are not limited to the following examples.

[0030] [Production of roasted coffee beans] Example 1 After measuring the volume (bulk A) of 150 g of green coffee beans (Arabica variety, produced in Brazil), they were placed in a stainless steel mesh container and sprayed with 1500 mL of pure water (temperature 25°C) for 5 minutes using a pendulum-type mist sprayer ("#89" manufactured by Maruhachi Sangyo). After spraying, the surface of the green coffee beans was lightly wiped with a paper rag ("Kimtowel" manufactured by Nippon Paper Crecia Co., Ltd.), and the volume (bulk B) of the green coffee beans was measured and the bulk increase rate was calculated. Next, the green coffee beans were roasted using a roaster (Probat "Sample Roaster"). The roasting temperature was 160°C, and the roaster was set at 70% heat and damper at 0.5 to 0.6. The green coffee beans were roasted to an L* value of 19.5 to 20.5 to obtain roasted coffee beans. The L* value is a measurement value of ground coffee beans obtained from the roasted coffee beans.

[0031] Example 2 The volume (bulk A) of 150 g of green coffee beans (Arabica variety, produced in Brazil) was measured, then placed in a stainless steel mesh and left to stand for 15 minutes in an atmosphere of saturated steam (temperature 95°C) using a steamer ("Tea Manufacturing Machine Type 2K" manufactured by Kawasaki Kiko Co., Ltd.) The surface of the green coffee beans after the steam treatment was lightly wiped with a paper cloth ("Kimtowel" manufactured by Nippon Paper Crecia Co., Ltd.), and the volume (bulk B) of the green coffee beans was then measured and the bulk increase rate was calculated. Next, the green coffee beans were roasted in the same manner as in Example 1 to obtain roasted coffee beans.

[0032] (Examples 3 and 4) Roasted coffee beans were obtained in the same manner as in Example 2, except that the treatment time with water vapor was changed to the time shown in Table 1.

[0033] Example 5 After measuring the volume (bulk A) of 150 g of green coffee beans (Arabica variety, produced in Brazil), the beans were placed in a stainless steel mesh container and sprayed with 150 mL of pure water (temperature 25°C) for 0.5 minutes using a pendulum-type mist sprayer (Maruhachi Sangyo's "#89"). After lightly wiping the surface of the green coffee beans with a paper cloth (Nippon Paper Crecia Co., Ltd.'s "Kimtowel"), the green coffee beans were placed in a steamer (Kawasaki Kiko Co., Ltd.'s "Tea Machine 2K Type") and allowed to stand for 10 minutes in an atmosphere of saturated steam (temperature 95°C). After lightly wiping the surface of the green coffee beans after the steam treatment with a paper cloth (Nippon Paper Crecia Co., Ltd.'s "Kimtowel"), the volume (bulk B) of the green coffee beans was measured and the bulk increase rate was calculated. Next, the green coffee beans were roasted in the same manner as in Example 1 to obtain roasted coffee beans.

[0034] (Examples 6 to 8) Roasted coffee beans were obtained in the same manner as in Example 5, except that the amount and time of water spray and the time of steam treatment were changed to the conditions shown in Table 1.

[0035] Example 9 150 g of green coffee beans contained in a nonwoven bag ("Dustman" manufactured by Kureha Corporation) and 1000 mL of pure water (temperature 25°C) were placed in a 2000 mL stainless steel beaker (manufactured by AS ONE Corporation) and left to stand for 5 minutes. After leaving to stand, the surface of the green coffee beans was lightly wiped with a paper cloth ("Kimtowel" manufactured by Nippon Paper Crecia Co., Ltd.), and the volume of the green coffee beans was measured to determine the bulk increase rate. The bulk increase rate of the green coffee beans is shown in Table 1. Next, the green coffee beans were roasted in the same manner as in Example 1 to obtain roasted coffee beans.

[0036] (Comparative Examples 1 to 7) In Comparative Example 1, no treatment was performed, and in Comparative Examples 2 to 7, roasted coffee beans were obtained in the same manner as in the Examples, except that the treatment conditions were changed to those shown in Table 1.

[0037] The bulk increase rate of green coffee beans, the L* value of ground coffee beans, and the hardness of roasted coffee beans were measured as follows. The measurement results are shown in Table 1.

[0038] (Volume increase rate of green coffee beans) Using a 500 mL graduated cylinder (manufactured by AS ONE Corporation), the bulk A of 150 g of green coffee beans before treatment and the bulk B of the green coffee beans after treatment were measured. The bulk (volume) increase rate was calculated using the formula: Bulk (volume) increase rate (%) = 100 × [(bulk B (mL) - bulk A (mL)) / bulk A (mL)].

[0039] (L* value of ground coffee beans) 20 g of roasted coffee beans were ground using a coffee mill (Ditting Company's "KR-804"). The grind adjustment dial was set to 9, and grinding was carried out for 10 seconds to obtain coarsely ground ground coffee beans. Using a Hunter color difference meter (Konica Minolta, Inc.'s "CR410"), the L* value of three points on the ground coffee beans was measured, and the arithmetic average value was taken as the L* value of the ground coffee beans.

[0040] (Hardness of roasted coffee beans) Using a digital force gauge ("High-performance digital force gauge ZTA-1000N" manufactured by Imada Co., Ltd.) attached to an electric measuring stand ("MX2-1000N" manufactured by Imada Co., Ltd.), the roasted coffee beans were placed on the stage with the center cut facing downwards, a vertical load was applied to the roasted coffee beans, and the load (kgf) was measured at the point when the beans cracked. The load (kgf) of 10 roasted coffee beans was measured, and the arithmetic average value was taken as the hardness of the roasted coffee beans.

[0041] [Production of coffee extract] (Examples 1 to 9, Comparative Examples 1 to 7) 70 g of roasted coffee beans were ground using a coffee mill (Ditting Company's "KR-804"). The grind size adjustment dial was set to 9, and grinding was carried out for 10 seconds to obtain coarsely ground coffee beans. Next, 70 g of ground coffee beans and 700 mL of water (95°C) were added to a French press coffee maker ("BRAZIL 10948-01J" manufactured by Bodum), stirred six times, and then left to stand for four minutes. After standing, the mixture was filtered using a coffee filter (Daiso Industries Co., Ltd., 2-4 cups, unbleached type, material: virgin pulp) to obtain a coffee extract (extracted coffee liquid). After cooling to room temperature (25°C), the pH of the coffee extract was adjusted to 6.3 to 6.7 using sodium bicarbonate. The pH (25°C) was measured using a pH meter (Horiba Ltd., "Desktop pH Meter F-72"). The Brix value of the coffee extract was then adjusted to 1.0 using pure water. The Brix value (25°C) was measured using a digital refractometer (Atago Co., Ltd., "RX-5000").

[0042] [Evaluation of coffee extract] The transmittance (%) of the coffee extract was measured and a sensory evaluation was performed according to the following method. The results are shown in Table 1.

[0043] (transmittance) The coffee extract was filled into a can and the can was rolled up to produce a canned coffee beverage. The canned coffee beverage was sterilized at 123°C for 7 minutes using a retort sterilizer (Hisaka Manufacturing Co., Ltd., "type: RCS-60 / 1OST", F value: approximately 10) to produce a canned coffee beverage. After cooling to room temperature (25°C), the coffee extract was poured out of the canned coffee beverage, and the transmittance A (%) at a wavelength of 660 nm was measured using an ultraviolet-visible spectrophotometer (Shimadzu Corporation, "UV-1800", optical path length 10 mm). The coffee beverage produced in the same manner was allowed to stand (heat) for 14 days in an atmosphere at 60° C. After being allowed to cool to room temperature (25° C.), the coffee extract was poured out of the canned coffee beverage, and the transmittance B (%) was measured using an ultraviolet-visible spectrophotometer (Shimadzu Corporation, “UV-1800”). The difference in transmittance (%) was calculated from the formula: Difference in transmittance (%) = Transmittance A (%) - Transmittance B (%).

[0044] (Sensory evaluation) After leaving the canned coffee beverages for 14 days in an atmosphere at 60°C, a sensory evaluation was carried out by a panel of experts. The evaluation items and criteria were as follows:

[0045] (Intensity of turbidity) 4: No turbidity observed after heating, extremely good. 3: Less cloudiness after heating. 2: The liquid becomes slightly cloudy after heating. 1: Very cloudy after heating. (Coffee-derived flavor and concentration) 4: The aroma and strength of coffee is strongly felt. 3: You can feel the aroma and strength of coffee. 2: The aroma and strength of coffee is difficult to detect. 1: Coffee flavor and concentration is weak. (Cleanliness (absence of impurities)) 4: It has a clean taste without any unpleasant aftertaste. 3: Few impurities. 2: There is an unpleasant taste. 1: Strong impurities. (bitterness from coffee) 4: You can strongly taste the bitterness of the coffee. 3: You can taste the bitterness of coffee. 2: You will hardly notice the bitterness of coffee. 1: The bitterness from the coffee is weak and not very satisfying to drink.

[0046] [Table 1]

Claims

1. Processing green coffee beans so that the bulk increase rate is 32.0 to 41.0%; and Roasting the treated green coffee beans. A method for producing roasted coffee beans, comprising:

2. The process, The method comprises: soaking green coffee beans in water having a temperature of 0 to 40°C; and Steam treatment of coffee beans that have been soaked in water The method for producing roasted coffee beans according to claim 1, comprising:

3. The method for producing roasted coffee beans according to claim 1, wherein the hardness of the roasted coffee beans is 3.0 to 4.0 kgf.

4. Roasted coffee beans obtained by the method for producing roasted coffee beans according to any one of claims 1 to 3.

5. A coffee extract obtained by using the roasted coffee beans according to claim 4 as a raw material.

6. 6. The coffee extract according to claim 5, wherein the difference (A%-B%) between the transmittance B% for light with a wavelength of 660 nm after heating at 60° C. for 14 days and the transmittance A% for light with a wavelength of 660 nm before heating is 1.0% or less.

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