KR102313745B1 - Method for manufacturing decaffeinated coffee beans - Google Patents

Abstract

The present invention relates to a method for removing caffeine from coffee beans while maintaining taste and aroma. Since each step of the present invention does not use an organic solvent and does not require expensive equipment, decaffeinated beans can be effectively and inexpensively manufactured.

Description

Method for manufacturing decaffeinated coffee beans

The present invention relates to a method for removing caffeine from coffee beans while maintaining taste and aroma. Specifically, the present invention relates to a method for efficiently removing caffeine from coffee beans without using an organic solvent and without requiring expensive equipment.

As coffee has become a daily culture in modern society, the development of decaffeinated coffee for people sensitive to caffeine has also begun to accelerate.

Conventionally known methods for producing decaffeinated coffee include an indirect solvent method, a direct solvent method, a method using a filter, and a supercritical carbon extraction method. In the indirect solvent method, the coffee beans are soaked in water first, then the water is separated, the coffee beans are soaked in methylene chloride and ethyl acetate solvent, and the coffee beans are washed. A way to taste it. In the direct solvent method, coffee beans are steamed and immediately soaked in methylene chloride or ethyl acetate solvent to remove caffeine. Although this solvent method is not harmful to the human body, it causes consumers' reluctance to use organic solvents such as methylene chloride or ethyl acetate. There are no downsides.

On the other hand, the method using a relatively recently developed filter is to first soak coffee beans in water to extract taste and aroma components including caffeine, then filter it with an activated carbon filter to filter out caffeine, and then add the coffee beans to the water separated in the primary filtration. It is a method of removing caffeine by filtration in the same way. This method is used as an eco-friendly method because it does not use an organic solvent and can remove caffeine at a fairly high level. However, once separated components are oxidized and deteriorated, there is a limit to reuse of water, and thus a certain amount of coffee beans are continuously discarded in the intermediate stage, which inevitably causes a lot of industrial loss and increases the price of decaffeinated beans.

Supercritical carbon dioxide is also used in place of organic solvents, which is mainly used for processing large volumes of commercial grade coffee. Contrary to theory, the supercritical carbon dioxide method has a problem in that many organic components, including caffeine, are eluted from the coffee beans and removed, and the supercritical carbon dioxide facility itself is expensive, so it can be applied only when producing a large amount of decaffeinated coffee, Produced coffee also has a disadvantage in that it is somewhat difficult to maintain the taste and aroma.

On the other hand, Korea Patent No. 10-2072657 discloses a method for producing decaffeinated coffee beans using carbonated water, and the method of removing caffeine includes only the step of adding carbonated water to call the beans. The removal efficiency is low, and there are no additional measures to maintain the taste and aroma.

In order to solve the above problems, in one aspect, soaking raw coffee beans in water, and filtering the water with an activated carbon filter; Separating water and coffee beans, and decaffeination of the separated raw coffee beans in a carbon dioxide injection chamber; adding the separated water to decaffeinated raw coffee beans and aging; And it provides a method for producing decaffeinated coffee beans comprising the step of drying the aged decaffeinated raw beans.

A method for producing decaffeinated coffee according to an aspect specifically comprises: soaking raw coffee beans in water at 60 to 80 °C; filtering the water soaked in raw coffee beans with an activated carbon filter; separating the filtered water and transferring the raw coffee beans to a carbon dioxide injection chamber; decaffeination by adding water to raw coffee beans and injecting carbon dioxide while cooling to 15° C. or less; removing the carbon dioxide-infused water from the decaffeinated raw coffee beans, adding the separated water, and aging for 24 hours or more; and drying the aged decaffeinated raw coffee beans.

It is preferable that the beans used for decaffeination are raw coffee beans. If caffeine is removed after roasting, there is a high probability of eluting the flavor and aroma components in the coffee beans, and the already flavor and aroma components are heated during roasting and are often volatile. this is high

The step of soaking the raw coffee beans in water is to extract the flavor and aroma components from the raw coffee beans in advance. In this case, when the temperature of the water used exceeds 80° C., there is a risk that some taste and flavor components, such as the roasting effect, may be altered and removed during the decaffeination process. Therefore, it may be preferable to open the pores of the raw coffee beans and perform at a temperature of 60°C to 80°C, more preferably 70°C to 80°C, as a temperature that does not affect the taste and aroma. The step of calling raw coffee beans is preferably performed until the pores of the beans are widened and feels a little soft, and it can be carried out for more than 6 hours, preferably 8 hours to 12 hours, and sealed so that the taste and aroma do not evaporate It is preferable to do it in a confined space. It is preferable to use about 1.0 to 1.5 times the volume of water used to call raw coffee beans. If too much water is used, the concentration of the components dissolved in the water is low, so it may be difficult to re-apply the above components to the raw coffee beans.

The water used to make raw coffee beans is separated from raw coffee beans, and then filtered through an activated carbon filter to separate water and raw coffee beans. In this process, caffeine is filtered through an activated carbon filter, and flavor and aroma components are drained out with the water. The activated carbon filter used herein may be adjusted to a suitable degree to separate caffeine according to the type of coffee or the state of raw coffee beans, but is suitable for, for example, filtering out substances with a molecular weight of 190 g/mol or more by targeting caffeine molecules. As such, the diameter of the pores may be 15 to 30 Å, and it is preferable that the pores in the above range occupy about 50% or more of the total volume.

The separated raw coffee beans are directly transferred to the carbon dioxide injection chamber.

The amount of water added in the decaffeination step is 60° C. to 80° C., and it may be preferable that the amount of water is 0.5 to 1.5 times the volume of raw coffee beans.

In order to generate carbonic acid, 0.5 to 1.5 times, preferably 1 time of the volume of green beans is poured into the chamber with water at a temperature similar to that of green beans, for example, 60° C. to 80° C., and carbon dioxide is injected while Cool down the temperature slowly.

The separated raw beans are put into the chamber at a high temperature of 60° C. to 80° C. In this case, carbon dioxide may be difficult to dissolve in water. However, if the temperature of the water added to dissolve the carbon dioxide in the water is too low, the pores of the raw coffee beans are closed and the elution of caffeine may be difficult. Therefore, it is preferable for efficiency to set the initial temperature to the raw coffee beans and inject carbon dioxide while cooling the temperature gradually. On the other hand, if the temperature of the chamber is too low, the decaffeination efficiency may decrease, so decaffeination may be performed at 25° C. or less, preferably 15 to 25° C., more preferably 15 to 20° C. close to room temperature. .

Caffeine has a good binding force with carbon dioxide, so it is easily eluted in carbonated water compared to other ingredients. However, if too much water is poured compared to the volume of raw beans, the amount of carbon dioxide injected must be increased, the process time is prolonged, and the residual taste and flavor can easily escape by osmotic pressure regardless of the binding force with carbon dioxide, so keep the water ratio. It is preferable to give

Decaffeination may vary depending on the amount of coffee beans added, and may be performed until 90% or more of caffeine is removed, for example, it may be performed for 1 hour or more, 2 hours or more, or 2 to 4 hours. However, the present invention is not limited thereto. In the step of soaking in water before decaffeination, the taste and aroma of coffee beans are already eluted in water, but in order to maintain the remaining taste and aroma as much as possible, decaffeination is preferably performed within 4 hours. The decaffeination is performed at a level of 2 to 5 bar, such as a general household carbonated water maker, and does not require high pressure like supercritical carbon extraction.

When the decaffeination is completed, water is removed from the decaffeinated raw coffee beans, and the separated water is added and aged. Aging may be carried out in a closed container for 24 hours or more, preferably 24 hours to 48 hours, or 24 hours to 36 hours.

The aging may be performed at 30 to 50 °C.

The aging temperature is maintained at 30-50 ℃, preferably 35-45 ℃ to carry out with the pores of the raw beans open, and slowly cooled to room temperature, for example, 25 ℃ or less 1 hour before the end of aging. it is preferable

The drying may be performed at 15° C. or less.

The prepared decaffeinated raw beans are preferably carried out at 15° C. or lower to prevent the taste and flavor captured in the beans from evaporating. A reduced pressure drying method can be used for efficient drying at a low temperature in a short time.

The manufacturing method comprises the steps of: roasting dried decaffeinated beans; And it may further comprise the step of freeze-drying the extract of the roasted decaffeinated beans.

The dried decaffeinated beans can be directly roasted to prepare a freeze-dried product. If decaffeinated raw beans are directly roasted and freeze-dried and then packaged, the hassle of drying raw coffee beans to a moisture content of 10 to 15%, which is a sellable level, is reduced, and contact with oxygen is minimized to prevent deterioration or evaporation of taste and flavor. can be blocked In addition, the prepared freeze-dried product is immediately vacuum-packed and commercialized, so that it is possible to provide a product with a richer taste and fragrance to consumers. Before roasting the decaffeinated raw coffee beans, in order to prevent the taste and flavor from being changed due to the boiling of the remaining water during the roasting, the moisture of the decaffeinated raw coffee beans added to the roasting is 40% or less, preferably 25% to 35% It can be %.

Roasting is a process in which raw coffee beans are roasted to further enhance the taste and aroma, and the specific ingredients in the raw coffee beans are combined to further enhance the flavor. It could be my work. Roasting may be performed at an appropriate level depending on the purpose of coffee, such as light roasting, medium roasting, city roasting, French roasting, espresso roasting, and the like.

The manufacturing by freeze-drying includes: crushing roasted decaffeinated beans into bean powder; adding water at 80 to 100° C. to the coffee bean powder only enough to wet the coffee bean powder; steaming for 30 seconds to 1 minute; adding water at 80 to 100° C. to the steamed bean powder again and extracting coffee within 30 seconds to 1 minute at a pressure of 10 to 12 bar; and cooling the extracted coffee to -5°C to 4°C and drying. The lyophilisate may be additionally pulverized.

The freeze-dried product may contain 10% to 20% of freeze-dried beans based on the total weight of the freeze-dried product. When coffee beans are added to the freeze-dried product of the coffee extract, the taste and flavor can be further enhanced.

The freeze-dried beans are roasted decaffeinated raw beans and then powdered and freeze-dried immediately without an extraction step. After drying so that the moisture content of the freeze-dried beans is 5% or less, 45 μm to 80 μm, preferably 45 μm It can be added by finely pulverizing to 50 μm in size. If the size of the freeze-dried product of coffee beans is too large, it cannot be dissolved in water and remains at the bottom, causing a bitter taste.

By using the decaffeinated coffee bean manufacturing method according to an aspect, the caffeine can be removed while maintaining the taste and aroma of the beans as much as possible. In addition, the manufacturing method does not require an organic solvent during the manufacturing process, does not discard the coffee beans, and does not require expensive equipment such as supercritical carbon extraction, so it is economical.

Hereinafter, examples and the like will be described in detail to help the understanding of the present invention. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the following examples. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art.

Example 1: Preparation of decaffeinated beans

In order to manufacture decaffeinated beans, Santos from Brazil was obtained and administered in the decaffeinated state in the state of light greenish gray raw beans. Specifically, 100 g of raw coffee beans were poured with water at about 75° C. only enough to submerge the beans, and the temperature was maintained for about 10 hours, and the water was separated by pouring it into a device equipped with an activated carbon filter. Put the separated water in an airtight container, move the raw coffee beans directly to the carbon dioxide injection chamber, pour about 75℃ water just enough to submerge the beans again, cool the chamber to 20℃ while injecting carbon dioxide, and decaffeinate for about 3 hours did. Then, the carbonated water was removed, the separated water was poured, sealed, and aged at 40°C for about 24 hours, and the beans were re-applied with flavor and aroma. Then, water was removed from the beans through a sieve, and the water was removed under reduced pressure at about 15°C.

Comparative Example 1: Preparation of decaffeinated beans using only carbon dioxide chamber

It was prepared in the same manner as in Example 1, except that the coffee beans were soaked and then directly administered to a carbon dioxide chamber without going through an activated carbon filter step, followed by a decaffeination step using carbonated water. In this case, since the water soaked in the beans is applied immediately, the maturation step is not necessary. Since the amount of caffeine remaining may be too high because the activated carbon filter step was not performed, the step in the carbon dioxide chamber was performed for about 5 hours.

Comparative Example 2: Manufacture of decaffeinated beans using only activated carbon filter

It was prepared in the same manner as in Example 1, but after passing through an activated carbon filter, the aging step was carried out immediately without a decaffeination step using a carbon dioxide chamber to prepare decaffeinated beans.

Test Example 1: Caffeine measurement

It was evaluated whether decaffeination of each coffee bean was properly performed according to the manufacturing method. Caffeine measurement was performed in the same way as the general test method of the Ministry of Food and Drug Safety. Specifically, the prepared Example 1, Comparative Example 1, and Comparative Example 2 medium roasted was ground, 1 g was mixed in 20 ml water at 100 ° C., and deposited for 1 minute, followed by centrifugation to obtain only the supernatant. Then, 5 ml of the extract was passed through the reverse phase cartridge at a rate of 3 to 4 ml per minute, and the solution eluted with 15 ml of a mobile phase solution (methanol:acetic acid:water=20:1:79) was used as the test solution. For the caffeine standard solution, precisely weighed 0.1 g of the caffeine standard, dissolved in water to make 100 mL, was used as the standard stock solution, and diluted with water to 1∼㎍/mL was used as the standard solution for the calibration curve. Then, it was measured using liquid chromatography, and the conditions were as follows.

[Liquid Chromatography Conditions]

Detector: UV photometric detector, 280 nm

Column: Capcell Pak C18 (4.6 mm × 250 mm, 5 μm) or equivalent

Mobile phase flow rate: 1.0 mL/min

Injection volume: 10 μl

The caffeine content of the sample was calculated by comparing the peak height and area of the standard solution by qualitative and quantitative analysis at 280 nm, which is the maximum absorption wavelength of caffeine, through an ultraviolet absorbance detector while performing liquid chromatography. The results are shown in Table 1 below.

Caffeine content (mg/mL) Example 1 0.02 Comparative Example 1 0.12 Comparative Example 2 0.21

As can be seen from Table 1, in the case of Example 1, the caffeine content was very low at 0.02 mg/ml. Comparative Examples 1 and 2 had a caffeine content of 0.1 mg/ml or more. Comparative Example 1 had a high caffeine content even though the decaffeination time was increased in consideration of the low caffeine removal rate. Considering that commercial coffee has an average of 0.4 mg/ml, Comparative Examples 1 and 2 also contain less caffeine to some extent, but it was evaluated that caffeine was not removed properly because there was a difference of more than 6 times compared to Example 1.

Test Example 2: Volatile component measurement

Roasted coffee contains various volatile components that give it aroma and taste. Among them, the content of volatile components was compared with the sum of furfuryl alcohol, which is known to have a high content in coffee, and 2-propanone. On the other hand, Comparative Example 2 was excluded from the following tests because the caffeine content was too high and there was no need to proceed with an additional test.

Specifically, after roasting each bean and grinding under the same conditions, 1 g was put into a 20ml headspace vial, filled with nitrogen gas, and sealed with a cap. Then, the extracted coffee beans were analyzed for each target component using Headspace G/C and GC-MS equipment for fragrance component analysis. Each analysis condition is as follows.

[Headspace G/C conditions]

Instrument: Perkin-Elmer (Waltham, MA, USA) autosystem clarus 600

Column: Elite-5MS, 30 m×0.22 mm×0.25 μm

Carrier gas: Helium (1.5 mL/min)

Injector temp.: 150℃

Detector temp.: 230℃

Oven temp.: 40℃ for 3 min, 6℃/min, 190℃ for 15 mi

[GC-MS conditions]

Instrument: Library Perkin-Elmer turbomass clarus 600T

Electron voltage: 70 eV

Mass range: 20～300 amu

Injector temp.: 190℃

Ion source temp.: 210 ℃

Scan rate: 0.5 sec

Computer system: Turbochrom

Library: Wiley & NiST library file

The fragrance component was identified by comparing it with the library search data of the GC-MS spectrum, and the area of each pick was calculated only for the components of furfuryl alcohol and 2-propanone, which are generally high in content, and are shown in Table 2 below. indicated.

furfuryl alcohol 2-propanone Example 1 25.18 10.36 Comparative Example 1 21.03 8.38

As a result, Example 1 was evaluated to have more volatile component content than Comparative Example 1, even though it was further subjected to an activated carbon filter step. This is considered to be because the taste and aroma components of Comparative Example 1 were largely lost in the step of washing with carbon dioxide.

Test Example 3: Sensory evaluation

For sensory evaluation, 10 people who have worked in the coffee industry for 3 years or more and 10 people who are not related to the coffee industry on behalf of general consumers were selected as a panel for sensory evaluation. The coffee extraction method extracts coffee by pouring hot water into the coffee bean powder, soaking it for a few minutes, and pressing it with a device with a filter in order to eliminate differences in taste that may occur due to the skill of the brewer and the equipment, etc. It was extracted by the French press method. Example 1 and Comparative Example 1 extracted as described above were allowed to drink to each panel, and then indicated on each item. For precise evaluation, experts notified that it was decaffeinated coffee, subdivided the evaluation items, added the evaluation items, and averaged the average, and the general panel evaluated only the taste and flavor without notifying that it is decaffeinated coffee because there is a possibility that a narrow evaluation may occur. did. Each item was given a maximum score of 5 points.

coffee industry worker public aroma acidity zest sugar content average taste incense Example 1 3.2 2.8 3.6 2.8 3.1 4.0 3.8 Comparative Example 1 1.8 2.3 1.9 2.1 2.0 3.5 2.4

As a result, Comparative Example 1 received a low score in all items. In particular, in the case of Comparative Example 1, although the expert panel was notified that it was decaffeinated coffee, it received a very low score in aroma and flavor. Comparative Example 1 had an overall low content of volatile components as evaluated in Test Example 2, so it was an expected result.

Claims (7)

Soaking raw coffee beans in water at 60 to 80 °C;
filtering water and raw coffee beans with an activated carbon filter;
separating the filtered water and transferring the raw coffee beans to a carbon dioxide injection chamber;
decaffeination by adding water to raw coffee beans and injecting carbon dioxide while cooling to 15° C. or less;
removing the carbon dioxide-infused water from the decaffeinated raw coffee beans, adding the separated water, and aging for 24 hours or more; and
A method for producing decaffeinated coffee beans comprising the step of drying aged decaffeinated raw beans. The method according to claim 1, wherein the water added in the decaffeination step is 60°C to 80°C, and 0.5 to 1.5 times the volume of green beans. The method according to claim 1, wherein the aging is carried out at 30 to 50 ℃ method. The method according to claim 1, wherein the drying step is performed at 15 ℃ or less. The method according to claim 1, wherein the manufacturing method comprises: roasting dried decaffeinated beans; and freeze-drying the extract of the roasted decaffeinated beans. The method according to claim 1, wherein the preparing by freeze-drying comprises: crushing roasted decaffeinated beans into bean powder; adding water at 80 to 100° C. to the coffee bean powder only enough to wet the coffee bean powder; steaming for 30 seconds to 1 minute; adding water at 80 to 100° C. to the steamed bean powder again and extracting coffee within 30 seconds to 1 minute at a pressure of 10 to 12 bar; and cooling and drying the extracted coffee to -5°C to 4°C. delete