Liquid coffee extract

Abstract

To provide a coffee extract with increased coffee-specific aroma and reduced off-flavors.SOLUTION: A coffee extract comprises 2,3-butanedione, guaiacol and 4-ethylguaiacol. In the coffee extract, the ratio of (a) the concentration (ppb) of 2,3-butanedione to (b) the total concentration (ppb) of guaiacol and 4-ethylguaiacol [(a) / (b)] is 3.1 or more, and the coffee solid content (Brix) is 20-40%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a coffee extract and the like. Specifically, the present invention relates to a coffee extract and the like in which the aroma specific to coffee is enhanced and unpleasant flavors are suppressed. [Background technology]

[0002] It is desirable to obtain a coffee extract from commonly used coffee ingredients that has a distinctive coffee aroma and suppresses unpleasant flavors. The development of such a coffee extract would be a great commercial advantage in that it would enable a high-quality coffee extract to be provided stably and inexpensively.

[0003] Patent Document 1 describes a method for producing a concentrated coffee extract by passing a hot aqueous medium through a set of extraction towers (percolator towers) and combining an evaporation concentration step with the extraction step. Patent Document 2 also describes a method for producing a concentrated coffee extract by passing hot water through a set of extraction columns. However, because typical coffee ingredients also contain many impurity components, there is a problem that when coffee is extracted from such ingredients using a normal extraction method, the impurity components are also extracted along with the pleasant aroma unique to coffee. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 47-20370 [Patent Document 2] Japanese Patent Application Publication No. 52-125670 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a coffee extract in which the aroma specific to coffee is enhanced and unpleasant flavors are suppressed. [Means for solving the problem]

[0006] The present inventors have conducted intensive research to solve the above problems, and as a result have found that, in a coffee extract containing 2,3-butanedione, guaiacol, and 4-ethylguaiacol, a coffee solids concentration (Brix) of the coffee extract is adjusted to 1%, and the ratio [(A) / (B)] of (A) the peak area ratio of 2,3-butanedione to (B) the sum of the peak area ratios of guaiacol and 4-ethylguaiacol in a solution is adjusted to 7.0 or more, thereby providing a coffee extract with an enhanced coffee-specific aroma and suppressed unpleasant flavors. The present inventors have also found that a coffee extract having an enhanced coffee aroma and suppressed unpleasant flavors can be provided by adjusting the ratio [(a) / (b)] of (a) the concentration (ppb) of 2,3-butanedione to (b) the total concentration (ppb) of guaiacol and 4-ethylguaiacol in a coffee extract containing 2,3-butanedione, guaiacol, and 4-ethylguaiacol to be 3.1 or more, and have completed the present invention.

[0007] That is, the present invention relates to, but is not limited to, the following: (1) A coffee extract containing 2,3-butanedione, guaiacol, and 4-ethylguaiacol, wherein the ratio [(A) / (B)] of the peak area ratio of (A) 2,3-butanedione to the sum of the peak area ratios of (B) guaiacol and 4-ethylguaiacol in a solution adjusted to a coffee solids concentration (Brix) of the coffee extract is 7.0 or more, wherein the peak area ratio is the ratio of the peak area of ​​each component to the peak area of ​​borneol when the peak areas are measured by gas chromatography mass spectrometry using 10 ppb of borneol as an internal standard substance. (2) The coffee extract according to (1), wherein the ratio [(A) / (B)] is 8.0 to 30.0. (3) A coffee extract according to (1) or (2), having a coffee solids concentration (Brix) of 20 to 40%. (4) A beverage comprising the coffee extract according to any one of (1) to (3). (5) A coffee extract comprising 2,3-butanedione, guaiacol and 4-ethylguaiacol, The coffee extract, wherein the ratio [(a) / (b)] of (a) the concentration (ppb) of 2,3-butanedione to (b) the total concentration (ppb) of guaiacol and 4-ethylguaiacol in the coffee extract is 3.1 or more. (6) The coffee extract according to (5), wherein the ratio [(a) / (b)] is 3.4 to 30.0. (7) The coffee extract according to (5) or (6), having a coffee solids concentration (Brix) of 20 to 40%. (8) A beverage comprising the coffee extract according to any one of (5) to (7). Effect of the Invention

[0008] According to the present invention, it is possible to provide a coffee extract in which the characteristic coffee aroma is enhanced and unpleasant flavors are suppressed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Coffee extract In one aspect, the present invention is a coffee extract containing 2,3-butanedione, guaiacol, and 4-ethylguaiacol, wherein the ratio [(A) / (B)] of the peak area ratio of (A) 2,3-butanedione to the total value of the peak area ratio of (B) guaiacol and the peak area ratio of 4-ethylguaiacol in a solution adjusted to a coffee solids concentration (Brix) of 1% is 7.0 or more. In another aspect, the present invention is a coffee extract containing 2,3-butanedione, guaiacol, and 4-ethylguaiacol, wherein the ratio [(a) / (b)] of the concentration (ppb) of (a) 2,3-butanedione to the total concentration (ppb) of (b) guaiacol and 4-ethylguaiacol in the coffee extract is 3.1 or more. By adopting such a configuration, it is possible to provide a concentrated coffee extract in which the aroma specific to coffee is enhanced and unpleasant flavors are suppressed. In this specification, the terms "coffee-specific aroma" and "aroma felt at the top" refer to the sweet aroma of freshly ground coffee. In addition, in this specification, the term "highly clean" refers to the absence of unpleasant flavors.

[0010] In this specification, the term "coffee extract" refers to a liquid extracted from coffee beans. Examples of coffee extracts include an extract obtained by extracting roasted coffee beans with a solvent such as water, a diluted or concentrated extract, and a slurry containing coffee beans or ground coffee beans. Therefore, in one embodiment, the coffee extract of the present invention is a concentrated coffee extract. In this specification, the term "concentrated coffee extract" refers to a coffee extract having a higher coffee solids concentration than a general coffee extract.

[0011] In this specification, "coffee beans" may refer to any of green coffee beans, roasted coffee beans, and roasted and ground coffee beans. In addition, in this specification, "green coffee beans" refers to coffee beans before they undergo a roasting process, which is a process in which coffee beans are heated and roasted, "roasted coffee beans" refers to coffee beans after they have undergone a roasting process, and "roasted and ground coffee beans" refers to those obtained by grinding coffee beans that have undergone a roasting process.

[0012] In the present invention, the origin and variety of coffee beans are not particularly limited. For example, coffee bean origins include Brazil, Colombia, Tanzania, Mocha, Kilimanjaro, Mandheling, Blue Mountain, etc., and coffee bean varieties include Arabica, Robusta, Liberica, etc. Coffee beans from a single origin or variety may be used, or beans from different origins or varieties may be used in combination. The variety of coffee beans used in the production of the coffee extract of the present invention is not particularly limited, but it is preferable to use Arabica beans or Robusta beans.

[0013] In the present invention, the roasting method and roasting conditions for obtaining roasted coffee beans from raw coffee beans are not particularly limited. For example, a direct fire type, hot air type, semi-hot air type, charcoal fire type, far infrared type, microwave type, superheated steam type, or other method can be used, and a horizontal (horizontal) drum type, vertical (vertical) drum type, vertical rotating bowl type, fluidized bed type, pressurized type, or other device can be used, and the coffee beans can be roasted to a degree of roast (light, cinnamon, medium, high, city, full city, French, Italian) appropriate for a specific purpose according to the type of coffee beans.

[0014] In the roasted and ground coffee beans used in the present invention, the roasting temperature for obtaining roasted coffee beans is not particularly limited, but is preferably 100 to 300°C, more preferably 150 to 250°C, and particularly preferably 170 to 220°C. The roasting time for obtaining roasted coffee beans is also not particularly limited, but is preferably 5 to 30 minutes, more preferably 10 to 25 minutes, and particularly preferably 15 to 20 minutes. Furthermore, the roasting degree of the roasted coffee beans is also not particularly limited, but it is preferable to roast the beans to be preferably 10 to 30, more preferably 10 to 25, and particularly preferably 15 to 25, using the L value measured by a color difference meter as an index. The roasting degree is measured by putting the ground beans into a cell, tapping sufficiently, and then measuring with a spectrophotometer. As the spectrophotometer, SE-2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. can be used.

[0015] Furthermore, the grinding method for obtaining the roasted and ground coffee beans used in the present invention is not particularly limited, and general methods such as dry grinding and wet grinding can be used.

[0016] 1-1.2,3-Butanedione The coffee extract of the present invention contains 2,3-butanedione, which is a component that contributes to the aroma unique to coffee. The peak area ratio of 2,3-butanedione in a solution in which the coffee solids concentration (Brix) of the coffee extract of the present invention is adjusted to 1% is not particularly limited as long as the ratio of the peak area ratio of (A) 2,3-butanedione to the sum of the peak area ratios of (B) guaiacol and 4-ethylguaiacol [(A) / (B)] is within a predetermined range, but is preferably 0.3 to 3.0, more preferably 0.5 to 2.0, and even more preferably 0.8 to 1.2. If the peak area ratio of (A) 2,3-butanedione in the coffee extract of the present invention is too low, the aroma unique to coffee will be insufficient, while if the peak area ratio of (A) 2,3-butanedione is too high, the balance of the entire aroma of coffee will be lost, and an unusual sweetness different from that of coffee will be felt.

[0017] In this specification, the "peak area ratio" means the ratio of the peak area of ​​the target component to the peak area of ​​borneol (10 ppb) when the peak area is measured by gas chromatography mass spectrometry using 10 ppb of borneol as an internal standard. Quantitative analysis methods include the calibration curve method using a standard substance of the target component and the internal standard method using an internal standard solution that is not present in the sample, but both are calculated based on the peak area value obtained when gas chromatography mass spectrometry is performed, so the values ​​calculated by both methods are considered to be correlated. The gas chromatography mass spectrometry conditions are as follows. GC main unit: Agilent Technologies 7890A ·MS Detector: Agilent Technologies 5975C inert XL MSD with Triple-Axis Detector -Pretreatment device: MultiPurpose Sampler MPS for GC Sample injection conditions: Dynamic Headspace (DHS) method Sample temperature: 80℃ Pressure 160kPa Septum purge flow rate: 3 mL / min Splitless Mode Column: HP-INNOWAX (length: 60 m, diameter: 0.250 mm, thickness: 0.25 μm) Flow rate 1.5 mL / min Pressure 160 kPa Oven: 40℃→240℃ (7.5℃ / min) Post run: 10 min. In the above analysis, salt may be added to the sample as necessary to promote volatilization of aroma components into the head space.

[0018] In addition, as long as the ratio [(a) / (b)] of the concentration (ppb) of (a) 2,3-butanedione to the total concentration (ppb) of (b) guaiacol and 4-ethylguaiacol described below is within a predetermined range, the concentration (ppb) of 2,3-butanedione per 1% Brix in the coffee extract of the present invention is not particularly limited, but is preferably 5.0×10 -3 ~1.0×10 5 ppb, more preferably 1.0×10 -2 ~8.0×10 4 ppb, and even more preferably 1.5×10 -2 ~5.0×10 4 If the concentration of (a) 2,3-butanedione in the coffee extract of the present invention is too low, the aroma specific to coffee becomes insufficient, whereas if the concentration of (a) 2,3-butanedione is too high, the balance of the overall coffee aroma is lost, and an unusual sweetness different from that of coffee is perceived.

[0019] 1-2. Guaiacol and 4-ethylguaiacol The coffee extract of the present invention contains guaiacol and 4-ethylguaiacol, which are components that contribute to the unpleasant taste characteristic of coffee. The total value of the peak area ratio of guaiacol and the peak area ratio of 4-ethylguaiacol in a solution in which the coffee solids concentration (Brix) of the coffee extract of the present invention is adjusted to 1% is not particularly limited as long as the ratio [(A) / (B)] described below is within a predetermined range, but is preferably 0.1 to 1.5, more preferably 0.1 to 0.5, and even more preferably 0.1 to 0.35. If the total value of the peak area ratio of (B) guaiacol and the peak area ratio of 4-ethylguaiacol in the coffee extract of the present invention is too low, the so-called "coffee feeling" due to bitterness and unpleasant taste will be reduced, and if the total value of the peak area ratio of (B) guaiacol and the peak area ratio of 4-ethylguaiacol is too high, the unpleasant taste characteristic of coffee will be too strong.

[0020] In addition, as long as the ratio (a) / (b) described below is within a predetermined range, the total concentration (ppb) of guaiacol and 4-ethylguaiacol per 1% Brix in the coffee extract of the present invention is not particularly limited, but is preferably 1.5×10 -3 ~1.0×10 4 ppb, more preferably 2.0×10 -3 ~8.0×10 3 ppb, and even more preferably 3.0×10 -3 ~5.0×10 3 If the total concentration of (b) guaiacol and 4-ethylguaiacol in the coffee extract of the present invention is too low, the so-called "coffee flavor" due to bitterness and other unpleasant flavors will be reduced, whereas if the total concentration of (b) guaiacol and 4-ethylguaiacol is too high, the unpleasant flavors specific to coffee will become too strong.

[0021] In one embodiment, the concentration (ppb) of guaiacol per 1% Brix in the coffee extract of the present invention is preferably 7.0×10 -4 ×~5.0×10 3 ppb, more preferably 1.0×10 -3 ~4.0×10 3 ppb, and even more preferably 1.5×10 -3 ~2.5×10 3 ppb.

[0022] In one embodiment, the concentration (ppb) of 4-ethylguaiacol per 1% Brix in the coffee extract of the present invention is preferably 7.0×10 -4 ~5.0×10 3 ppb, more preferably 1.0×10 -3 ~4.0×10 3 ppb, and even more preferably 1.5×10 -3 ~2.5×10 3 ppb.

[0023] 1-3. (A) The ratio of the peak area of ​​2,3-butanedione to the sum of the peak area of ​​guaiacol and the peak area of ​​4-ethylguaiacol (B) [(A) / (B)] In a solution in which the coffee solids concentration (Brix) of the coffee extract of the present invention is adjusted to 1%, the ratio [(A) / (B)] of the peak area ratio of (A) 2,3-butanedione to the sum of the peak area ratios of (B) guaiacol and 4-ethylguaiacol is 7.0 or more, preferably 8.0 to 30.0, more preferably 9.0 to 20.0, and even more preferably 10.0 to 15.0. If the ratio [(A) / (B)] is too low, the off-flavor characteristic of coffee becomes too strong, whereas if the ratio [(A) / (B)] is too high, the balance of the overall coffee aroma is lost, and an unusual sweetness different from that of coffee is felt.

[0024] In one embodiment, the ratio [(a) / (b)] of (a) the concentration (ppb) of 2,3-butanedione to (b) the total concentration (ppb) of guaiacol and 4-ethylguaiacol in the coffee extract of the present invention is preferably 3.1 or more, more preferably 3.4 to 30.0, even more preferably 3.6 to 20.0, and particularly preferably 13.8 to 15.0.

[0025] 1-4. Coffee solids concentration The coffee solids concentration of the coffee extract of the present invention is not particularly limited, but is preferably 20 to 40%, more preferably 25 to 37%, and particularly preferably 30 to 35%, in Brix value.

[0026] The Brix value is the refractive index measured at 20°C using a saccharometer or refractometer, converted into the mass / mass percentage of the sucrose solution based on the conversion table of the International Commission on Uniform Methods of Sugar Analysis (ICUMSA), and represents the soluble solids content in a beverage. The unit may be expressed as "Bx", "%" or "degrees". If the Brix value of a beverage is low, the content of soluble solids in the beverage, including sugar, is low.

[0027] 2. Beverage One aspect of the present invention is a beverage containing the aforementioned coffee extract. In the present invention, the aforementioned coffee extract can be used as a beverage as is, or can be concentrated or diluted as necessary to make a beverage. The type of beverage is not particularly limited, but is preferably coffee, a coffee beverage, a coffee-containing soft drink, a coffee-containing soft drink (caffeine-free), or a coffee-containing carbonated beverage. These beverages are defined in Article 2 of the Fair Competition Code on the Labeling of Coffee Beverages, etc.

[0028] If necessary, the beverage of the present invention may contain one or more additives such as bitterness suppressants, antioxidants, flavorings, various esters, organic acids, organic acid salts, inorganic acids, inorganic acid salts, inorganic salts, colorants, emulsifiers, preservatives, seasonings, acidulants, quality stabilizers, etc. Furthermore, when the beverage of the present invention is coffee, a coffee beverage, a coffee-containing soft drink, a coffee-containing soft drink (caffeine-free), or a coffee-containing carbonated beverage, it may be drunk black, or a sweetener such as milk or sugar may be added.

[0029] Furthermore, the beverage of the present invention can also be a packaged beverage. The type of container is not particularly limited, but for example, a molded container mainly made of polyethylene terephthalate (so-called PET bottle), a metal can, a paper container combined with a metal foil or a plastic film, a bottle, or other ordinary packaging container can be used.

[0030] Furthermore, when containerized beverages can be filled into containers such as metal cans and then heat sterilized, they can be produced under sterilization conditions stipulated in applicable laws and regulations (such as the Food Sanitation Act in Japan). For containers that cannot be sterilized by retort, such as PET bottles and paper containers, a method can be used in which the beverage is sterilized under the same sterilization conditions as above, for example, sterilized at high temperature for a short time using a plate-type heat exchanger, cooled to a certain temperature, and then filled into containers.

[0031] 3. Method for producing coffee extract The coffee extract of the present invention contains 2,3-butanedione, guaiacol and 4-ethylguaiacol, and the production method thereof is not particularly limited as long as the ratio [(A) / (B)] of the peak area ratio of (A) 2,3-butanedione to the total value of the peak area ratio of (B) guaiacol and the peak area ratio of 4-ethylguaiacol in a solution adjusted to a coffee solids concentration (Brix) of the coffee extract is within the above-mentioned range. In one embodiment, the coffee extract of the present invention contains 2,3-butanedione, guaiacol and 4-ethylguaiacol, and the production method thereof is not particularly limited as long as the ratio [(a) / (b)] of the concentration (ppb) of (a) 2,3-butanedione to the total concentration (ppb) of (b) guaiacol and 4-ethylguaiacol in the coffee extract is within the above-mentioned range. For example, it can be produced by combining continuous multi-tube extraction and evaporation concentration. Specifically, the coffee extract of the present invention can be produced through a) a first extraction step in which water at 70 to 120°C is supplied to a column packed with roasted and ground coffee beans to obtain a coffee extract, b) a second extraction step in which water at 125 to 150°C is supplied to the column packed with the roasted and ground coffee beans used in the first extraction step to obtain a coffee extract, c) a step of evaporating and concentrating the coffee extract obtained in the second extraction step, and d) a step of mixing the coffee extract obtained in the first extraction step with the evaporated and concentrated coffee extract.

[0032] To produce the coffee extract of the present invention, for example, a first extraction step can be used in which a coffee extract is obtained by supplying water at 70 to 120° C., preferably 90 to 110° C., and more preferably 95 to 105° C. to a column packed with roasted and ground coffee beans. The column volume of the extraction column used in the first extraction step is not particularly limited, but is preferably 10 to 50 L, more preferably 15 to 30 L, and even more preferably 20 to 25 L.

[0033] In the first extraction step, the rate at which water is supplied per 1 L of column volume packed with roasted and ground coffee beans is not particularly limited, but water is preferably supplied at a flow rate of 1.0 to 10.0 kg / h per 1 L of column volume, more preferably at a flow rate of 2.0 to 7.0 kg / h per 1 L of column volume, and even more preferably at a flow rate of 3.0 to 5.0 kg / h per 1 L of column volume. In this specification, for example, supplying water at a flow rate of 1.0 to 10.0 kg / h per 1 L of column volume means that when the volume of the column used is 5 L, water is supplied to the column at a flow rate of 5.0 to 50.0 kg / h.

[0034] The extraction rate of the extract obtained in the first extraction step is not particularly limited, but is preferably 10.0 to 23.0%, more preferably 12.0 to 21.0%, and even more preferably 14.0 to 20.0%.

[0035] In the first extraction step, from the viewpoint of obtaining a coffee extract rich in aroma components specific to coffee, it is preferable to connect a plurality of extraction columns filled with roasted and ground coffee beans in series and perform continuous extraction. The number of extraction columns in the first extraction step is preferably 2 or more, more preferably 2 to 10, and particularly preferably 3 to 6. When a plurality of extraction columns is used, for example, a coffee extract is obtained by supplying water at 70 to 120°C to a first extraction column filled with roasted and ground coffee beans, and then the coffee extract obtained from the first extraction column is supplied to a second extraction column filled with roasted and ground coffee beans, so that the coffee extract can be extracted continuously by successively changing the extraction columns.

[0036] The volume of the extraction column used to produce the coffee extract of the present invention is not particularly limited, and the packing density of the roasted and ground coffee beans packed in the extraction column is not particularly limited, but the amount of moistened roasted and ground coffee beans is preferably 0.20 to 0.50 kg / L (0.20 to 0.50 kg of moistened roasted and ground coffee beans per 1 L of column volume), more preferably 0.25 to 0.40 kg / L, and even more preferably 0.28 to 0.35 kg / L.

[0037] The amount of coffee extract collected from the extraction column is not particularly limited as it varies depending on the column volume and the amount of roasted and ground coffee beans packed in the column, but is preferably 0.05 to 0.50 kg per 1 L of column volume, more preferably 0.08 to 0.30 kg per 1 L of column volume, and particularly preferably 0.10 to 0.20 kg per 1 L of column volume. As described above, the present invention also includes an embodiment in which a plurality of extraction columns packed with roasted and ground coffee beans are connected in series to perform continuous extraction, but the amount of coffee extract collected per 1 L of column volume is the amount collected per one extraction column.

[0038] In order to produce the coffee extract of the present invention, a second extraction step can be included after the first extraction step in which relatively high-temperature water is supplied to the column packed with the roasted and ground coffee beans used in the first extraction step to obtain a coffee extract.

[0039] In the second extraction step, a column packed with the roasted and ground coffee beans used in the first extraction step is used. To produce the coffee extract of the present invention, for example, the extraction temperature in the second extraction step is 125 to 150°C, preferably 125 to 140°C, and more preferably 125 to 135°C.

[0040] The column volume of the extraction column used in the second extraction step is not particularly limited, but is preferably 10 to 50 L, more preferably 15 to 30 L, and even more preferably 20 to 25 L.

[0041] Furthermore, in the second extraction step, it is preferable to maintain the temperature of the column packed with roasted and ground coffee beans during the extraction step, and the column temperature in the second extraction step is preferably 125 to 150°C, more preferably 125 to 140°C, and even more preferably 125 to 135°C.

[0042] In the second extraction step, the rate at which water is supplied per 1 L of column volume packed with roasted and ground coffee beans is not particularly limited, but it is preferable to supply water at a flow rate of 1.0 to 10.0 kg / h per 1 L of column volume, it is more preferable to supply water at a flow rate of 2.0 to 8.0 kg / h per 1 L of column volume, and it is even more preferable to supply water at a flow rate of 4.0 to 6.0 kg / h per 1 L of column volume.

[0043] The extraction rate of the coffee extract obtained in the second extraction step is not particularly limited, but is preferably 4.0 to 14.0%, more preferably 6.0 to 13.0%, and even more preferably 8.0 to 12.0%.

[0044] The coffee solids concentration of the coffee extract obtained in the second extraction step is not particularly limited, but is preferably 0.3 to 3.0%, more preferably 0.5 to 2.5%, and even more preferably 1.0 to 2.0%, in Brix value.

[0045] In addition, the number of extraction columns used in the second extraction step is not particularly limited, but from the viewpoint of obtaining a high-concentration coffee extract, it is preferable to connect multiple extraction columns filled with roasted and ground coffee beans in series and perform continuous extraction. The number of extraction columns in the second extraction step is preferably 2 or more, more preferably 2 to 10, and particularly preferably 3 to 6. When multiple extraction columns are used, for example, a coffee extract is obtained by supplying water at 125 to 150°C to a first extraction column filled with roasted and ground coffee beans, and then the coffee extract obtained from the first extraction column is supplied to a second extraction column filled with roasted and ground coffee beans, and thus the coffee extract can be extracted continuously by successively changing the extraction columns.

[0046] The volume of the extraction column used in the second extraction step is not particularly limited. The packing density of the roasted and ground coffee beans packed in the extraction column is also not particularly limited, but the amount of the moistened roasted and ground coffee beans is preferably 0.2 to 0.5 kg / L, more preferably 0.25 to 0.40 kg / L, and even more preferably 0.28 to 0.35 kg / L.

[0047] Furthermore, the amount of coffee extract collected from the extraction column in the second extraction step is not particularly limited, but is preferably 0.5 to 5.0 kg per 1 L of column volume, more preferably 0.8 to 3.0 kg per 1 L of column volume, and particularly preferably 1.0 to 1.5 kg per 1 L of column volume.

[0048] Furthermore, in order to produce the coffee extract of the present invention, a step of evaporating and concentrating the coffee extract obtained in the second extraction step can be included after the second extraction step.

[0049] In the second extraction step, a column filled with the roasted and ground coffee beans used in the first extraction step is used, so even if the extraction is performed at a high temperature, the extraction efficiency of the coffee extract is not very high. In addition, when coffee is extracted at a high temperature, a large amount of impurity components are also contained in the extract. Therefore, by evaporating and concentrating the coffee extract after the second extraction step, the concentration of the coffee extract can be increased and the impurity components can be volatilized to suppress the impurity in the coffee extract.

[0050] The heating temperature in the evaporation and concentration step is preferably 100 to 120°C, more preferably 105 to 115°C, and particularly preferably 108 to 112°C.

[0051] In order to produce the coffee extract of the present invention, a step of mixing the coffee extract obtained in the first extraction step with the coffee extract evaporated and concentrated after the second extraction step can be included. As described above, in the first extraction step, a coffee extract that maintains a good aroma and flavor specific to coffee can be obtained by extracting at a low temperature (70 to 120°C). In addition, a high-concentration coffee extract with reduced unpleasant flavors can be obtained by evaporative distillation after the second extraction step. Therefore, by mixing the coffee extract obtained in the first extraction step with the coffee extract evaporated and concentrated after the second extraction step, a coffee extract with an enhanced aroma specific to coffee and reduced unpleasant flavors can be produced.

[0052] In order to produce the coffee extract of the present invention, the mixing ratio of the coffee extract obtained in the first extraction step and the coffee extract evaporated and concentrated after the second extraction step is not particularly limited, and the coffee extract obtained in the first extraction step and the coffee extract evaporated and concentrated after the second extraction step can be mixed as appropriate so that the coffee extract after mixing has a desired Brix value. In producing the coffee extract of the present invention, the coffee solids concentration of the coffee extract obtained by mixing the coffee extract obtained in the first extraction step and the coffee extract evaporated and concentrated after the second extraction step is preferably 20 to 40%, more preferably 25 to 37%, and particularly preferably 30 to 35%, in terms of Brix value. EXAMPLES

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

[0054] (1) Manufacturing of roasted and ground coffee beans Green coffee beans (Arabica variety, produced in Brazil) were roasted in a coffee roaster (manufactured by Probat) so that the L value was 20. The roasted coffee beans were then ground in a roll mill (manufactured by GEA) to obtain roasted and ground coffee beans.

[0055] (2) Coffee extract production (i) First extraction step The roasted and ground coffee beans produced in (1) above were wetted with water (20 wt%) in an extraction column (GEA: volume 23 L), and then packed to a bean weight of 7.0 kg / column. Then, 100°C water was supplied to the column at an extraction temperature of 100°C and a flow rate of 80 kg / hour, and extraction was performed so that the amount of collected liquid was 3 kg. Next, the roasted and ground coffee beans were packed in the second column so that the amount of wetted beans was 7.0 kg / column, and extraction was performed in the same manner with two columns connected to each other so that the amount of collected liquid was 3 kg. Furthermore, the roasted and ground coffee beans were packed in the third column so that the amount of wetted beans was 7.0 kg / column, and extraction was performed in the same manner with three columns connected to each other so that the amount of collected liquid was 3 kg. The beans in the first column, which had been extracted three times, were then sent to a process for collecting the second extract, and the roasted and ground coffee beans were packed in the fourth column so that the amount of wetted beans was 7.0 kg / column, and extraction was performed in the same manner with three columns connected to each other so that the amount of collected liquid was 3 kg. This extraction process was repeated (1 to 18 batches), and 10 to 18 batches of extracts that provided stable extraction rates and Brix values ​​were mixed together to obtain a coffee extract after the first extraction process. The measurement results for each batch are shown in Table 1. The final amount of coffee extract after the first extraction process was 29.82 kg, with a Brix of 29.21% and an average extraction rate of 17.92%. [Table 1]

[0056] (ii) Second extraction step Up to four columns filled with the roasted and ground coffee beans used in the first extraction step (i) above were connected in series. Then, 130°C water was supplied to the column so that the extraction temperature was 130°C and the flow rate was 120 kg / h, and extraction was performed so that the collected liquid volume was 25 kg and the target extraction rate was 10%. After the beans were discharged from the column after four extractions, new beans were filled and used again in the first extraction step. The extraction step was repeated (4 to 18 batches: 1 to 3 batches did not have a second extraction step because the first extraction step was not completed), and 10 to 18 batches of extracts with stable extraction rates and Brix values ​​were mixed to obtain a coffee extract after the second extraction step. The measurement results for each batch are shown in Table 1. The final amount of coffee extract after the second extraction step was 247.74 kg, the Brix was 1.80%, and the average extraction rate was 9.16%.

[0057] (iii) Evaporative distillation process About 250 kg of the coffee extract after the second extraction step obtained in (ii) above was concentrated at a heating temperature of 110° C. and an evaporation temperature of 50° C. so that the coffee solids concentration in the extract was 50%. The amount of the coffee extract after the evaporation distillation obtained in (ii) after the second extraction step was 5.62 kg and the Brix was 55.18%.

[0058] (iv) Preparation of sample coffee extract <Inventions> The invention product was prepared by mixing 1.0 kg of the coffee extract obtained in the first extraction step (i) above and 0.297 kg of the coffee extract obtained by evaporating and concentrating the coffee extract obtained in the second extraction step (iii) above. The liquid volume of the invention product was 12.9 kg and the Brix was 34.0%.

[0059] <Existing products 1 to 5> Five types of coffee extract manufactured by other companies were used as existing products 1 to 5.

[0060] (3) Analysis of sample coffee extract The coffee solids concentration (Brix) of the coffee extracts of the invention product and existing products 1 to 5 was adjusted to 1%, and the peak area ratios of 2,3-butanedione, guaiacol, and 4-ethylguaiacol in the diluted coffee extracts were determined by gas chromatography mass spectrometry using 10 ppb of borneol as an internal standard. The gas chromatography mass spectrometry conditions were as follows: GC main unit: Agilent Technologies 7890A ·MS Detector: Agilent Technologies 5975C inert XL MSD with Triple-Axis Detector -Pretreatment device: MultiPurpose Sampler MPS for GC Sample injection conditions: Dynamic Headspace (DHS) method Sample temperature: 80℃ Pressure 160kPa Septum purge flow rate: 3 mL / min Splitless Mode Column: HP-INNOWAX (length: 60 m, diameter: 0.250 mm, thickness: 0.25 μm) Flow rate 1.5 mL / min Pressure 160 kPa Oven: 40℃→240℃ (7.5℃ / min) Post run: 10 min.

[0061] Table 2 shows the peak area ratios of 2,3-butanedione, guaiacol, and 4-ethylguaiacol in the inventive product and existing products 1 to 5. Table 2 also shows the ratio (A / B) of the peak area ratio of 2,3-butanedione to the total value of the peak area ratios of guaiacol and 4-ethylguaiacol. Table 3 also shows the concentrations of 2,3-butanedione, guaiacol, and 4-ethylguaiacol per 1% of the coffee solids concentration (Brix) of the coffee extracts of the inventive product and existing products 1 to 5. Table 3 also shows the ratio (a / b) of (a) the concentration of 2,3-butanedione to (b) the total concentration of guaiacol and 4-ethylguaiacol. As mentioned above, the coffee solids concentration (Brix) of the inventive product is 34.0%, so the concentrations of 2,3-butanedione, guaiacol, and 4-ethylguaiacol in the inventive product are 0.55 ppb, 0.05 ppb, and 0.09 ppb, respectively. [Table 2] [Table 3]

[0062] (4) Sensory evaluation test of coffee extract Next, the invention product and existing products 1 to 5 produced in (2) above were each diluted with hot water to a Brix of 1% to obtain sample beverages for sensory evaluation testing. Then, sensory evaluation was carried out for each sample beverage by a panel of experts (3 people). The sensory evaluation results for each sample beverage are shown in Table 4. [Table 4]

[0063] As shown in Tables 2 to 4, in the "invention product" in which the ratio [(A) / (B)] of the peak area ratio of (A) 2,3-butanedione to the total peak area ratio of (B) guaiacol and 4-ethylguaiacol in the coffee extract is within a specified range, the sensory evaluation comment was that the top aroma is sufficiently abundant and very clean, indicating that the coffee-specific aroma is enhanced and the unpleasant taste is suppressed. On the other hand, when [(A) / (B)] is below the range of the present invention, unpleasant taste and bitterness are felt. This is also true for the "invention product" in which the ratio [(a) / (b)] of the concentration (ppb) of (a) 2,3-butanedione to the total concentration (ppb) of (b) guaiacol and 4-ethylguaiacol in the coffee extract is within a specified range. It was shown that by setting the peak area ratio [(A) / (B)] and the concentration ratio [(a) / (b)] within the specified ranges, it is possible to provide a coffee extract that enhances the coffee's unique aroma and suppresses unpleasant flavors. [Industrial Applicability]

[0064] INDUSTRIAL APPLICABILITY The present invention provides a coffee extract in which the specific coffee aroma is enhanced and unpleasant flavors are suppressed, and therefore has high industrial applicability.

Claims

1. 1. A coffee extract comprising 2,3-butanedione, guaiacol and 4-ethylguaiacol, the ratio [(a) / (b)] of (a) the concentration (ppb) of 2,3-butanedione to (b) the total concentration (ppb) of guaiacol and 4-ethylguaiacol in the coffee extract is 3.1 or more; The coffee extract has a coffee solids concentration (Brix) of 20 to 40%.

2. 2. The coffee extract according to claim 1, wherein the ratio (a) / (b) is 3.4 to 30.0.

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