JP2003204757A - Method for producing concentrated coffee liquid where aroma component is recovered - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing flavored concentrated coffee liquid where aroma components lost during the process of concentrating extracted coffee liquid are efficiently recovered. <P>SOLUTION: The method for producing concentrated coffee liquid comprises the following processes: (A) concentrating coffee liquid extracted from roasted and ground coffee beans to classify it into concentrated liquid and free solution after concentration, (B) concentrating the free solution after concentration obtained in the process (A) using a reverse osmotic membrane (having an NaCl stopping rate of ≥99%) with an operating pressure of ≤0.98 MPa, and concentrating aroma components included in the free solution after concentration to obtain concentrated aroma liquid, and (C) mixing the concentrated liquid obtained in the process (A) with the concentrated aroma liquid obtained in the process (B) to prepare concentrated coffee liquid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a concentrated coffee liquid having a large amount of aroma by recovering aroma components lost in a coffee extract concentration process.

[0002]

2. Description of the Related Art In the process of producing concentrated coffee from a coffee extract, the aroma component of coffee is lost, and the obtained concentrated coffee has a problem of poor flavor.

A method of concentrating coffee using a reverse osmosis membrane is known as a method capable of suppressing the heating history of coffee liquid and producing concentrated coffee with a high flavor. For example, in JP-A-56-29954,
A two-stage reverse osmosis membrane concentration method is described. Regarding the collection of aroma components, JP-A-4-88948.
In the publication, the aroma component is recovered together with the solid content by the two-stage treatment, but this method has a second-stage concentration pressure of 3.9MP.
It is a or more, and at this pressure, the permeation pressure to the membrane surface is high and the solid content can be concentrated, but the aroma component is eluted to the permeate side. At this time, the aroma component lost from the coffee liquid is 30 to 60.
%, Which greatly affects the reduction of coffee flavor.

Further, as a method for preventing elution of aroma components into permeated water in membrane concentration, JP-A-63-237739 discloses a method of adding a fragrance-holding substance such as cyclodextrin. The addition of
It is not suitable because it causes restrictions in the application development to the final product using the concentrated liquid as a raw material.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a concentrated coffee liquor having a good taste by efficiently recovering aroma components lost in the coffee extract concentration process.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and found that the aroma component can be suitably recovered and concentrated by adjusting the operating pressure during filtration by a reverse osmosis membrane. The present invention has been completed and the present invention has been completed.

That is, the method for producing a concentrated coffee liquor of the present invention comprises the following steps: (A) a step of concentrating a coffee liquor extracted from roasted and crushed coffee beans and separating a concentrate and a concentration-removed liquid. ,
(B) The concentrated removal solution obtained in the step (A) is concentrated with a reverse osmosis membrane (NaCl inhibition rate of 99% or more) at an operating pressure of 0.98 MPa or less to concentrate the aroma component contained in the concentrated removal solution. To obtain a concentrated aroma liquid, and (C) the above (A)
The method is characterized by including a step of preparing a concentrated coffee liquid by mixing the concentrated liquid obtained in the step and the concentrated aroma liquid obtained in the step (B).

The concentration method in the step (A) is preferably membrane concentration, vacuum concentration or freeze concentration.

Further, the concentration method in the step (A) is membrane concentration, and it is preferable that concentration is performed using a reverse osmosis membrane (NaCl inhibition rate of 99% or more) at an operating pressure of 1.9 to 5.9 MPa.

Further, the operating pressure for concentrating the membrane is 2.
It is preferably 9 to 5.0 MPa.

[Operation and Effect] According to the method for producing a concentrated coffee liquid of the present invention, the aroma component eluted in the concentrated removal liquid is effectively made by concentrating the concentrated removal liquid with a reverse osmosis membrane having a high separation ability at an extremely low pressure. A concentrated coffee liquid having a high flavor can be provided by collecting and reducing the concentrated liquid.

The fragrance component of the concentrated fragrance liquid obtained in the step (B) of the present invention is a medium-mass gas chromatograph.
The ratio of components in the high boiling point area is higher than that before the reverse osmosis membrane treatment. Since the concentrated aroma liquid containing a large amount of such components improves the flavor of coffee, the method of the present invention is also effective for improving the aroma quality of the concentrated coffee liquid.

In the present invention, the concentration method in the step (A) is selected from membrane concentration, reduced pressure concentration or freeze concentration,
In particular, by concentrating the membrane using a reverse osmosis membrane,
It is possible to obtain a concentrated coffee liquid having good concentration efficiency and a high flavor.

Further, by setting the operating pressure for membrane concentration using the reverse osmosis membrane within a predetermined range, a concentrated coffee liquid having a good recovery rate of coffee solids in step (A) and a high flavor can be obtained. Obtainable.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The types of green coffee beans used in the present invention are:
The species are not particularly limited, and examples thereof include Arabica species, Robusta species, Reberica species, and the like. You may use the bean which blended several types.

The roasting of green coffee beans may be performed by a known method and apparatus, and the degree of roasting can be appropriately selected according to the intended coffee beverage.

The roasted coffee beans may be pulverized by a known method and apparatus, and the degree of pulverization is not particularly limited.

The ground coffee beans are loaded into the extractor. The extraction method is not particularly limited, and known methods and devices may be used. The water used for extracting the coffee is preferably ion-exchanged water, distilled water or the like in order to obtain coffee with a good flavor.

First, the step (A) of concentrating the extracted coffee liquid and separating the concentrated liquid and the concentrated removal liquid is carried out.

The concentrated liquid is a coffee liquid having a high solid content concentration, which is obtained by removing water from the extracted coffee liquid. The solid content concentration of the concentrated liquid is usually about 5 to 60% by weight, although it depends on the use of the concentrated coffee liquid as the final product. The solid content concentration is a value obtained by measuring the weight of the solid content remaining after the coffee liquid is dried under reduced pressure to evaporate the water content.

The concentrated / removed liquid is a liquid in which water is removed when the extracted coffee liquid is concentrated, and contains the aroma component of coffee lost from the concentrated liquid.

The concentration method is not particularly limited, and any known method and apparatus may be used, and membrane concentration, reduced pressure concentration, freeze concentration and the like are preferable. Above all, it is more preferable to concentrate the membrane with a high concentration efficiency because the history of heating the coffee liquid is small.

Examples of the membrane concentration method include a method using an ultrafiltration membrane or a reverse osmosis membrane. Commercially available membranes may be used, respectively, and the conditions may be such that the solid content recovery rate is good. The coffee extract is passed through the membrane under predetermined conditions to obtain a concentrate and a permeate. Here, the permeated liquid is subjected to the following step (B) as a concentrated removal liquid containing an aroma component.

The vacuum concentration method may be carried out by a known method and apparatus and is not particularly limited. Usually, coffee extraction is performed at a temperature of 30 to 90 ° C. under a reduced pressure of 6.6 to 80.0 kPa. Water is evaporated from the liquid to obtain a concentrated liquid. It is said that 95% of the fragrance component is scattered in the concentration under reduced pressure. The evaporated water is cooled, the fragrance component is condensed and collected together with the water, and the concentrated removal liquid is subjected to the following step (B).

The freeze concentration method may be carried out by a known method and apparatus and is not particularly limited. Usually, the coffee extract is frozen at -5 ° C. or lower to remove water, and the frozen ice is separated and removed. To obtain a concentrated solution. Aroma components are dissolved in the liquid discharged from the freeze concentration machine after melting the separated ice, and this is used as the concentrated removal liquid in the following step (B).

In the present invention, from the viewpoint of high recovery rate of coffee solids and good quality of the concentrate obtained, a reverse osmosis membrane (NaCl inhibition rate 99% among the above membrane concentration methods is used.
It is preferable to use the above) to concentrate at an operating pressure of 1.9 to 5.9 MPa.

In the step (A) of the present invention, the reverse osmosis membrane is not particularly limited as long as it is a reverse osmosis membrane having an NaCl inhibition rate of 99% or more, and a commercially available product can be preferably used. The NaCl inhibition rate is preferably 95% or more, and more preferably 99.90% or more, in order to increase the recovery rate of coffee solids.

The operating pressure during concentration by the reverse osmosis membrane is
To increase the recovery rate of coffee solids, 1.9 to 5.
9 MPa is preferable, and 2.9 to 4.9 MPa is more preferable.

Next, (B) the concentrated removal liquid obtained in the above step (A) is concentrated at a working pressure of 0.98 MPa or less using a reverse osmosis membrane (NaCl inhibition rate of 99% or more), and concentrated and removed. A step of concentrating the aroma components contained in the liquid to obtain a concentrated aroma liquid is performed.

The reverse osmosis membrane used in the step (B) of the present invention is for concentrating aroma components, but the reverse osmosis membrane described in the step (A) can be used. The reverse osmosis membranes of step (A) and step (B) may be of the same type or of different types.

In this step (B), the operating pressure at the time of concentration by the reverse osmosis membrane is 0.98 MPa or less in order to suppress the loss of aroma components, and 0.98 to 0.01
MPa is preferable, and 0.8 to 0.01 MPa is more preferable.

By this step, the concentrated removal liquid is usually 1 /
It is concentrated to about 2 to 1/10 to obtain a concentrated aroma liquid.

The concentrated aroma liquid obtained in this step contains an aroma component which is excellent in both quality and quantity, and is used in the following step (C). In addition, the concentrated aroma liquid is added to other foods for the purpose of adding the flavor of coffee. Can also be used as

Finally, a step (C) of mixing the concentrated liquid obtained in the step (A) and the concentrated aroma liquid obtained in the step (B) to prepare a concentrated coffee liquid is carried out.

The concentrated liquid and the concentrated aroma liquid can be mixed in any ratio so as to have a desired solid content and aroma.

The concentrated coffee liquid of the present invention thus obtained has the aroma component lost during the concentration well recovered, and can be suitably used for industrial raw materials, diluted beverages and the like.

[0038]

EXAMPLES Examples and the like specifically showing the constitution and effects of the present invention will be described below.

(Example 1) A reverse osmosis membrane (Daisen Membrane) having a polyamide polymer as an active layer and a polysulfone as a supporting layer was prepared from an industrial coffee extract (solid content: 1.8% by weight) obtained by a conventional method.・ Systems, product number DRA
9910, NaCl blocking rate 99.90%) 3.9M
It was concentrated at an operating pressure of Pa. The obtained concentrated liquid had a solid content of 17.2% by weight, the solid content concentration of the concentrated removal liquid (permeate) was 0.0% by weight, and there was no loss of coffee solids. Table 1 shows the solid content concentrations of the coffee liquid and the permeated liquid at the stage of concentration.

[0040]

[Table 1] Next, the permeate, the active layer is a polyamide-based polymer,
Reverse osmosis membrane whose support layer is polysulfone (manufactured by Daisen Membrane Systems Co., Ltd., product number DRA9910, N
It was concentrated at an operating pressure of 0.01 MPa at an ac rejection rate of 99.90%) until the liquid amount became 1/5 to obtain a concentrated aroma liquid. Regarding the aroma amount of the permeated liquid in the stage of concentration,
It was measured by gas chromatography.

[Measurement of aroma amount by gas chromatography] 10 ml of the permeated liquid was sampled in a 22 ml vial and sealed. The sealed vial bottle was heated to 80 ° C with an autosampler for gas chromatography manufactured by Tekmar.
After heating at 20 ° C. for 20 minutes, the sample was sampled and analyzed by gas chromatography.

Measuring conditions Measuring device: Hitachi Gas Chromatograph G-3000 Column: GL Sciences TC-WAX
0.53 mm × 30 m Carrier gas: Helium carrier gas Flow rate: 1 ml / min Column temperature: 40 ° C. (5 minutes) → 220 ° C. (heated at 5 ° C./minute) Detector: FID.

The total area of the peaks by gas chromatography analysis was calculated as the total aroma amount, and the value before concentration was 10
The comparison was made as 0%. In addition, each peak was classified into the following three areas based on the column temperature at the time of analysis, the peak area for each area was calculated, and the values before concentration were set to 100% and compared.

High boiling point area: Column temperature 101 ° C. to 20
0 ° C Medium boiling point area: Column temperature 41 ° C to 100 ° C Low boiling point area: Column temperature 40 ° C.

The results are shown in Table 2.

[0046]

[Table 2] From Table 2, it can be seen that the concentrated aroma liquid concentrated to a liquid amount of 1/5 has a total aroma amount increased by 4.2 times. Concentration of aroma components using a reverse osmosis membrane is an effective method for flavor recovery of coffee, since the aroma components in the middle and high boiling points, which have large losses due to concentration under reduced pressure, are concentrated 6 to 8 times.

(Comparative Example 1) In Example 1, the concentration and removal liquid (permeate) was reduced to 1 / th at an operating pressure of 3.9 MPa.
A concentrated aroma liquid was obtained in the same manner as in Example 1 except that the concentration was increased to 5. About the obtained concentrated aroma liquid,
The aroma amount was measured by gas chromatography. The results are shown in Table 3.

[0048]

[Table 3] From Table 3, the concentrated aroma liquid concentrated until the liquid amount becomes 1/5, the total amount of aroma increases about 3 times, and the aroma components in the middle and high boiling points are concentrated about 4 times. I understand. However, compared with Example 1, the method of Comparative Example 1 is inferior in the recovery rate of the aroma components.

(Reference Example 1) Loss of aroma component in concentration of reverse osmosis membrane An industrial coffee extract (solid content: 2.2% by weight) obtained by a conventional method was used as a polyamide-based polymer for the active layer and poly-based for the support layer. A solid content of 1 with a reverse osmosis membrane of sulfone (manufactured by Daisen Membrane Systems Co., Ltd., product number DRA9910, NaCl inhibition rate 99.90%) at an operating pressure of 3.9 MPa.
It was concentrated to 6.8% by weight. With respect to the extract and the permeate in the stage of concentration, the total amount of aroma was measured by gas chromatography as in Example 1, and the results are shown in Table 4.

[0050]

[Table 4] From Table 4, it can be seen that the aroma component was eluted on the permeated water side as the coffee liquid was concentrated, and the aroma amount in the coffee liquid was lost by 40%.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Kumori             7-7 Minatojima Nakamachi, Chuo-ku, Kobe-shi, Hyogo               UCC Ueshima Coffee Co., Ltd.             General planning room (72) Inventor Yoshiyuki Kitajima             7-7 Minatojima Nakamachi, Chuo-ku, Kobe-shi, Hyogo               UCC Ueshima Coffee Co., Ltd.             General planning room F term (reference) 4B027 FB21 FC01 FE06 FQ09 FQ11

Claims (4)

[Claims] 1. The following steps: (A) a step of concentrating a coffee liquid extracted from roasted and ground coffee beans and separating a concentrated liquid and a concentrated removal liquid;
(B) The concentrated removal solution obtained in the step (A) is concentrated with a reverse osmosis membrane (NaCl inhibition rate of 99% or more) at an operating pressure of 0.98 MPa or less to concentrate the aroma component contained in the concentrated removal solution. To obtain a concentrated aroma liquid, and (C) the above (A)
A method for producing a concentrated coffee liquid, comprising the step of preparing a concentrated coffee liquid by mixing the concentrated liquid obtained in the step and the concentrated aroma liquid obtained in the step (B). 2. The production method according to claim 1, wherein the concentration method in the step (A) is membrane concentration, reduced pressure concentration or freeze concentration. 3. The method according to claim 1, wherein the concentration method in the step (A) is membrane concentration, and the concentration is performed using a reverse osmosis membrane (NaCl inhibition rate of 99% or more) at an operating pressure of 1.9 to 5.9 MPa. The manufacturing method described. 4. The manufacturing method according to claim 3, wherein the operating pressure is 2.9 to 5.0 MPa.