KR20140011235A - Fermented coffee and process for preparing the same - Google Patents

Abstract

The present invention relates to: a production method of fermented green coffee beans including a step of fermenting green coffee beans or coffee endocarps; the fermented green coffee beans produced by the method; a production method of a fermented coffee extract including a step of hot water extracting the fermented green coffee beans; and the fermented coffee extract obtained by the method. Fermented coffee with improved flavor and taste is produced using the production method of the present invention, and the method can be widely applied to produce high quality coffee. [Reference numerals] (AA) Common green beans; (BB) Example 1; (CC) Example 2; (DD) Example 3

Description

Fermented coffee and process for preparing the same {Fermented Coffee and process for preparing the same}

The present invention relates to fermented coffee and a method for manufacturing the same, and more particularly, the present invention relates to a method for preparing fermented coffee beans, the fermented coffee beans produced by the method, and the fermented coffee beans. It relates to a method for producing a fermented coffee extract comprising the step of extracting hot water and a fermented coffee extract prepared by the above method.

Coffee is the most popular drink consumed in the world, and is being sold or consumed in the form of instant coffee, mixed coffee, canned coffee and coffee beans.

Coffee is cultivated in the region between 25 degrees and 25 degrees north latitude, called the coffee zone or coffee belt.The variety of coffee, characteristics of the cultivated area, drying method, roasting / crushing, etc. It is known that the flavor of coffee changes according to various factors.

Coffee varieties are divided into three categories: Arabica, Robusta and Riberica.Arabica (70%) is grown in high altitudes of 800m or higher in South America, Central America and Africa. ) The varieties and Robusta (25%) varieties, which are cultivated below 600m above sea level in Indonesia, Vietnam and Southeast Asia, are used as industrial raw materials, accounting for more than 95% of the total circulation. In particular, the coffee grown in the alpine region is known to have excellent flavor, the coffee of Arabica varieties produced at more than 1,500m above sea level is treated as the best coffee.

Coffee is largely dried by a dry process, a wet process and a mixed process. The dry processing method, also called a natural drying method, is a three-step process (washing-drying- peeling), which removes impurities from the harvested coffee berries and washes them under running water, and then cleans them in the sun in a large, sunny place. Therefore, it is dried for about 2 ~ 4 weeks so that the average moisture content is 10-12%. Brazil, Ethiopia, Ecuador, Indonesia, and Vietnam use this dry process a lot.

The wet processing method, also called flush drying method, removes the surgical skin (fruit) through a mechanical device, and mucous membrane (mucilage) covered in the endothelial skin through natural fermentation for 10 to 24 hours in water to remove the mucous, and wash and average The water content is titrated to about 57% and then dried by hot air drying, natural drying or mixed drying to obtain an average water content of 10-13%. This wet process requires a lot of equipment and labor, but the quality of green beans is known to be superior to the dry process. In Colombia and Guatemala, the wet process is applied to produce high quality Arabica coffee.

Dried coffee is stored and stored in the condition of parchment green bean with surgical skin removed from the mill, and after sale, the endothelial skin is removed and sold after packing and classifying defects.

Roasting is an important step in the coffee processing process. It is a process of applying heat until the right color and flavor is produced in the coffee beans. This is the stage at which the chemical reaction occurs. During roasting, green beans undergo endothermic / exothermic reactions, resulting in internal structural changes and expansions, and internal moisture, carbon dioxide, and volatile components move to the outside to evaporate, resulting in changes in green beans. The final flavor of coffee is determined by a combination of numerous chemical components, such as the breakdown of small molecules such as sugars, fats, and proteins, the maillard reaction of the resulting small molecules, and the decomposition of Strecker.

As such coffee has a variety of tastes and flavors by the production region, drying method and roasting method, efforts to develop a new roasting method, extraction method, processing method, etc. in order to improve / develop the flavor of the coffee continues.

On the other hand, in Indonesia, asia palm civet eats coffee fruit and finds that the coffee excreted has a less bitter taste and a better taste, and it is called kopi luwak which processed the excrement obtained from nature or excrement obtained through artificial breeding. Produces a unique and mellow flavor of coffee and is currently sold as the world's most expensive coffee. Since the kopi luwak is processed in the digestive system of musk cats, efforts are being made to develop a method of manufacturing coffee with improved flavor by artificially performing these steps. For example, Korean Patent Laid-Open Publication No. 10-2006-0100394 discloses a method for producing a floral and fruity coffee, comprising the step of fermenting coffee extracts with yeast or lactic acid bacteria, US Patent Publication No. 2009/0220645 The present invention discloses a coffee processing method comprising the step of simulating the digestive system of musk cats, and enzymatically treating the endothelial green beans at a low pH. US Patent Publication No. 2010/0239711 discloses a fungus of Eumycota. A process for enhancing the flavor of coffee by treating with is disclosed. However, the prior art has a problem in that the economic efficiency of the process is lowered, such as not applying microorganisms to the green coffee beans, or requiring a period of one month or more.

Under these circumstances, the present inventors have diligently researched to develop a method for enhancing the flavor of coffee, and as a result, the green beans and the parchment green beans are hygienic and safe as edible bacteria such as bacilli, lactic acid bacteria and yeast. When fermentation through the fermentation process, it was confirmed that the fermented coffee can be produced to improve the taste of the coffee and exhibit a variety of flavors and completed the present invention.

One object of the present invention is to provide a method for producing fermented green beans, which comprises the step of fermenting green beans or endothelial green beans of coffee.

Another object of the present invention to provide a fermented green beans prepared by the above method.

Still another object of the present invention is to provide a method for preparing a fermented coffee extract, comprising the step of extracting the fermented coffee beans from hot water.

Still another object of the present invention is to provide a fermented coffee extract prepared by the above method.

As one embodiment for achieving the above object, the present invention provides a method for producing fermented green beans comprising the step of fermenting green beans or endothelial green beans of coffee.

The present inventors prepared the fermented coffee beans by solid phase fermentation or liquid fermentation of the green peeled coffee beans obtained by removing the flesh from the coffee fruit or the green coffee beans obtained by removing the flesh from the fruit to make fermented coffee beans. The fermented green beans thus prepared may be used as beans after roasting (FIG. 1). 1 is a flow chart showing the step of producing a fermented green beans of the present invention.

As used herein, the term “green beans of coffee” means dried coffee beans.

As used herein, the term " coffee inner skin green beans " refers to green coffee beans which have been removed from surgical blood by milling dried coffee beans.

The term "fermentation" of the present invention means a process of decomposing organic matter using an enzyme possessed by fermented strains. For the purpose of the present invention, the fermentation may be carried out in the form of solid phase expression or liquid fermentation by inoculating fermentation strains on the green or inner skin of the coffee to enhance the taste and flavor of the coffee, but is not particularly limited thereto.

As used herein, the term "solid fermentation" refers to a process of fermenting endothelial green beans or green beans in a relatively dry environment, and more specifically, fermentation of the endothelial green beans or green beans without being immersed in the fermentation broth, or injection of the strain. It may be a fermentation process, but is not particularly limited thereto.

In addition, the term "liquid fermentation" of the present invention refers to the process of fermenting the inner skin green beans or green beans in a relatively wet environment, more specifically, the process of fermenting the inner skin green beans or green beans in the fermentation broth in a fermentation broth. It may be, but is not particularly limited thereto.

As used herein, the term “fermented strain” means a microorganism which can be inoculated into green or endothelial green coffee to enhance the taste and flavor of the coffee. For the purpose of the present invention, the fermented strain is inoculated in the green beans or endothelial green beans of the coffee, it can be edible bacteria. The "edible bacterium" as defined in Food Code, Second. Common Standards and Standards for Food General 2. Food Ingredients Standard 2) Means microorganisms that have been or have been used in foods in accordance with food ingredient judgment criteria. Fermentation strains used in the present invention is not particularly limited, but may preferably be lactic acid bacteria, Bacillus bacteria or yeast, more preferably Bacillus genus strains; Lactic acid bacteria such as Bifidobacterium spp., Lactobacillus spp., Lactococcus spp. Strain, Leukonostock strain, Pediococcus spp. Strain, Streptococcus spp. Or yeast such as strains of Saccharomyces, strains of Shijosaccharomyces, strains of Gojisaccharomyces, Hansenula, strains of Bretanomyces, strains of Decera, strains of Streptomyces Most preferably, Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus stearothermophilus, Bacillus coagulum Bacillus bacteria such as lance (Bacillus coagulans), Bacillus longum, Bacillus pumilus, Bacillus brevis, Bacillus circulans, Bacillus polymyxa, etc .; Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium lactis Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus gasseri, Lactobacillus delbruecki spp., Lactobacillus delbrueckii spp. Lactobacillus bulgaricus, Lactobacillus helveticus, Lactobacillus fermentum, Lactobacillus paracasei, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus family Lactobacillus Lactobacillus rhamnosus, Lactobacillus salivar ius), Lactococcus lactis, Leuconostoc mesenteroides, Pediococcus cerevisiae, Pediococcus asididilacci, Streptococcus lactis Lactic acid bacteria such as Streptococcus lactis, Streptococcus thermophiles, Streptococcus cremoris, etc .; Or Saccharomyces cerevisiae, Saccharomyces ellipsoideus, Saccharomyces coreanus, Saccharomyces carlsbergensis, Saccharomyces carlsbergensis Saccharomyces pastorianus, Saccharomyces lactis, Saccharomyces rouxii, Schizosaccharomyces pombe, Zigosaccharomyces major major, Hansenula anomala, Bretanomyces bruxellensis, Bretanomyces custersianus, Dekera anomala, Streptomyces oli Yeasts such as Streptomyces olivochromogenes and Streptomyces griseus Or it can mix and use.

Enzymes such as cellulase, protease, amylase, and lipase secreted by the fermentation strain decompose some macromolecules of green beans into small molecules (amino acids, monosaccharides, fatty acids, etc.). The converted small molecules undergo a Strecker reaction or Maillard reaction through a roasting process with a process temperature of more than 200 degrees and significantly affect the final coffee flavor. Cellulase, for example, breaks down the surface of cellulose composed of cellulose and the fibrous structure of the endothelium, allowing moisture to infiltrate the inside of the bean and allow other enzymes to easily transfer into the inside of the bean or endothelial bean. and; Proteases serve to reduce the bitter taste of coffee by degrading proteins contained in green or endothelial green beans into nonspecific units and hydrolyzing peptides that exhibit bitterness containing a large amount of hydrophobic residues; Amylase converts the carbohydrates of the polymers contained in green or inner skin into monosaccharides or disaccharides with strong sweetness, thereby increasing the sweetness of coffee and inhibiting indirect bitterness; Lipase penetrates the cell walls of green beans destroyed by cellulase, breaks down the triglycerides that make up the cell membrane and converts them into fatty acids, and facilitates the elution of lipids during coffee extraction to enrich the deep taste and body of coffee. In addition, the produced fatty acids are converted to volatile components of ketones or aldehydes during the high temperature roasting process to enhance the flavor of coffee.

It may further comprise the step of washing the green beans before fermenting the green beans or endothelial green beans, which can be carried out to remove foreign matters and the like on the surface of the green beans that may be harmful to the human body, this washing process is specifically Although not limited, it may preferably be carried out by washing 3 to 5 times in running water for 2 to 5 minutes. Further, sterilizing before performing the fermentation to stably ferment the washed green beans or endothelial green beans It may further include, but may be carried out alone or in combination with a conventionally used ultraviolet, ethanol treatment method, heat treatment method, but is not particularly limited thereto.

Next, the conditions for inoculating the fermented strains in the green beans are not particularly limited, but the inoculation amount is 0.01 to 5% (w / w), preferably 0.1 to 1% (w / w) based on the weight of the green beans. The number of cells can be inoculated so that the number of cells can be 5 to 9 logCFU / ml, preferably 6 to 7 logCFU / ml.

In addition, the inoculation method is preferably carried out by mixing the fermented strain in the form of powder with green beans or spraying the suspension of fermented strains on the surface of the green beans, a temperature condition of 20 to 45 ℃, preferably a temperature condition of 35 to 37 ℃ And 95 to 99% relative humidity, preferably 98% relative humidity. Preferably, the fermentation time is not particularly limited, but it is preferable to ferment for 6 to 168 hours, preferably 48 to 96 hours. In the case of using the inner skin, it is preferable to ferment at least 12 hours than the green beans. This fermentation step may be carried out in a fermenter, or may be carried out in a condition that does not use a fermenter. When using a fermenter, the fermenter is filled with about 1.5 to 3 times the weight of green beans and inoculated with fermentation strains. Next, the fermentation step may be performed by fermentation at a temperature of 10 to 60 ° C. for 6 to 168 hours, and at this time, purified cellulase may be added to increase the efficiency of the fermentation. The amount of added cellulase is not particularly limited, but is preferably added in a weight of 0.05 to 5% (w / w), preferably 0.1 to 1% (w / w) based on the green bean weight.

Finally, after the fermentation is finished, the step of quickly drying by washing or heating the surface may be further performed to prevent further fermentation of fermented green beans. At this time, as a drying method used may be a method such as using a constant temperature dryer or natural drying, hot air drying, it is preferable to dry so that the moisture content of green beans to 10 to 13%. After drying, it can be stored in a cool and low humidity place or vacuum-packed according to the general green bean storage method, and can be processed and used in the same way as general beans after the roasting process is completed.

As another embodiment for achieving the above object, the present invention provides fermented green beans prepared by the above method.

The term "fermented green beans" of the present invention refers to green beans in which some components of the coffee are chemically mutated by inoculating the above-mentioned fermented strains on the green beans or the inner skin of the coffee beans. For the purpose of the present invention, the fermented green beans have reduced protein content, increased lipid and carbohydrate contents, and caffeine, trigonellinic acid, and chlorogenic acid, which are the main components that express the bitter taste of coffee, compared to general green beans. Similar, amino acid content is significantly reduced, sugar content is significantly increased, and in terms of palatability, bitterness is reduced and sweetness, sourness, and flavor strength are enhanced compared to general coffee, indicating high satisfaction. .

As another embodiment for achieving the above object, the present invention provides a method for producing a fermented coffee extract by hydrothermally extracting the fermented beans and fermented coffee extract prepared by the method.

The fermented coffee extract may be prepared by hot water extraction of the fermented coffee beans, preferably, may be prepared by a series of steps of roasting, grinding and hot water extracting the fermented coffee beans according to a conventional method, in which the roasting of the fermented coffee beans Since various conditions such as degree, grinding degree of coffee beans, weight ratio of water and ground coffee, temperature of water, extraction time, etc. vary according to the preference of human beings, these conditions are not particularly limited, but are usually performed according to known extraction conditions. desirable.

By using the production method of the present invention, since the fermented coffee with improved taste and flavor can be prepared, it can be widely used for the production of coffee with improved quality.

1 is a flow chart showing the step of producing a fermented green beans of the present invention.
2 is a graph analyzing the amino acid content of fermented green beans and general green beans.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Example  One: Green beans Solid Fermentation

1kg of normal green beans and inner skins were washed three times for three minutes in flowing purified water, spread out in a container for good ventilation, and 1% fermented strain Pediococcus acidilatici (KCTC 13734) was suspended in 50 ml of distilled water and sprayed on the surface of green beans. The green beans were stirred during inoculation for an even distribution of the microorganisms. For hygienic fermentation, it was carried out for 72 hours at 35 degrees Celsius and 95% relative humidity in a sterile thermostat. The fermented green beans were dried by hot air dryer at 40 ° C until moisture content reached 11.3%, and then vacuum-packed until roasting.

Example  2: Inner skin Green beans Solid Fermentation

After washing three times for 3 minutes in purified water flowing 1kg of endothelial peeled green beans, they were spread out in a container for good ventilation, and 1% of fermented strain Bacillus subtilis (KCTC 3014) was suspended in 50ml of distilled water and sprayed on the surface of green beans. The green beans were stirred during inoculation for distribution. For sanitary fermentation, sterilized in a constant temperature and humidity chamber for 120 hours at 37 degrees Celsius and 98% relative humidity. After fermentation, dry and peel the inner skin until the moisture content reaches 11.3% with 40 degrees hot air. Vacuum packed until roasting.

Example  3: Inner skin Green beans  Liquid fermentation

After washing cleanly three times for three minutes in purified water flowing 1kg of Brazilian Santos inner rind, it was placed in a sterilized fermenter, and purified water of 2.5 times the inner rind was added. Fermentation strain Bacillus subtilis (KCTC 3014), Lactobacillus bulgalicus (KCTC 3635) 1% each was added to the fermenter and stirred until the end of fermentation for smooth mixing. The fermentation was carried out at 37 degrees Celsius for 96 hours. The fermented green peeled beans were naturally dried until the moisture content was 11.6%, and the inner skin was removed and vacuum-packed.

Example  4: Fermented green beans  Component analysis

For general green beans and fermented green beans prepared by the method of Examples 1-3, the protein, lipid, carbohydrate and ash contained in these green beans were measured and compared (Table 1).

Composition and Contents of Normal and Fermented Green Beans (%) Metric
General green beans
Fermented green beans Example 1 Example 2 Example 3 Crude protein
Lipid
Carbohydrate
Views min 13.2
12.0
60.3
3.5 12.7
13.5
61.1
3.6 12.7
13.5
61.1
3.6 12.7
13.2
60.9
3.5

As shown in Table 1, compared to the content of the various components contained in the general beans, the protein contained in the fermented beans decreased about 0.5%, lipids and carbohydrates increased by about 1 to 1.5%, ash content increased about 0.1% It was confirmed.

Example  5: bitter taste analysis

In general, it is known that the bitter taste of coffee is derived from caffeine, trigonellinic acid and chlorogenic acid, of which 10% is represented by caffeine and the remaining 90% is determined by trigonellinic acid and chlorogenic acid. .

Thus, the contents of the caffeine, trigonellinic acid and chlorogenic acid were measured by HPLC using a known Bradbury method for the general green beans and the fermented green beans prepared by the method of Examples 1-3. Comparison was made (Table 2).

Content ratio of bitter components of green and fermented green beans Metric
General green beans
Fermented green beans Example 1 Example 2 Example 3 Caffeine
Trigonellinic acid
Chlorogenic acid 1.04
0.87
4.66 1.04
0.90
4.64 1.03
0.88
4.66 1.03
0.86
4.66

As shown in Table 2, since there was no significant difference between the components showing the bitter taste in the general green beans and fermented green beans, it can be seen that the general green beans and fermented green beans do not show a difference in terms of bitter taste.

Example  6: Amino Acid Content Analysis

When using the fermentation method of the present invention, it was intended to determine whether the amino acid content is changed by the fermentation process. To this end, the contents of amino acids contained in the general green beans and fermented green beans prepared by the method of Example 1-3 were measured and compared (FIG. 2). Figure 2 is a graph comparing the amino acid content contained in the general beans and fermented beans prepared by the method of the present invention. As shown in Figure 2, it was confirmed that the amino acid content contained in the fermented beans is significantly reduced compared to the amino acid content contained in the general beans. In particular, it was found that the contents of leucine, isoleucine and phenylalanine, which are amino acids showing bitter taste, were significantly reduced in fermented green beans.

Example  7: Sugar Content Analysis

When using the fermentation method of the present invention, it was to determine whether the content of saccharides is changed by the fermentation process. To this end, the contents of glucose, sucrose, fructose, galactose and arabinose contained in the general green beans and each fermented green beans prepared by the method of Examples 1-3 were measured and compared (Table 3). At this time, the content of each sugar was measured by HPLC applying the method of Trugo and Jones.

Contents of Sugars of Regular and Fermented Green Beans (㎍ / g) Metric
General green beans
Fermented green beans Example 1 Example 2 Example 3 Glucose
Sucrose
Fructose
Galactose
Arabinos 530
1280
352
630
220 980
2349
525
1088
340 670
1452
474
825
364 780
2079
487
868
352

As shown in Table 3, it was confirmed that the content of the sugars contained in the fermented beans is significantly increased compared to the content of the sugars contained in the general beans. It was analyzed that polysaccharides such as oligosaccharides or polysaccharides contained in green beans were decomposed by fermentation.

Example  8: Sensory evaluation of fermented coffee

In order to evaluate the palatability of the coffee prepared from the fermented beans produced by the fermentation method of the present invention, six trained panels were selected and subjected to sensory evaluation.

General coffee beans and each fermented coffee beans prepared by the method of Example 1-3 were double roasted and ground to the same thickness, and 8 g of ground coffee was immersed in 150 ml of water and extracted to prepare respective general coffee and fermented coffee, The palatability of these prepared general and fermented coffees was evaluated three times by five-point measurement method (1: very weak, 2: weak, 3: normal, 4: strong, 5: very strong), and the average value was calculated and compared. (Table 4).

Sensory evaluation result Metric
General green beans
Fermented green beans Example 1 Example 2 Example 3 bitter
sweetness
Sour taste
incense
Body
General Symbol 4.1 ± 0.1
2.2 ± 0.2
3.4 ± 0.3
2.0 ± 0.3
3.7 ± 0.1
3.5 ± 0.1 2.8 ± 0.1
3.3 ± 0.3
3.9 ± 0.3
3.1 ± 0.3
3.2 ± 0.2
4.4 ± 0.3 3.5 ± 0.2
2.9 ± 0.2
4.0 ± 0.3
2.3 ± 0.3
3.4 ± 0.1
3.7 ± 0.4 2.9 ± 0.1
3.3 ± 0.2
3.6 ± 0.1
2.7 ± 0.3
3.3 ± 0.3
4.4 ± 0.1

As shown in Table 4, the fermented coffee was found to show a high satisfaction as the bitter taste is reduced and the strength of sweetness, sourness, and flavor is enhanced compared to general coffee.

Claims (19)

Fermented beans inoculated with the green beans or the inner skin of the coffee beans fermented strain manufacturing method comprising the step of fermentation.
The method of claim 1,
Wherein said fermented strain is an edible bacterium or yeast.
3. The method of claim 2,
Wherein said edible bacterium is a bacterium capable of producing enzymes that affect the surface or green skin of the green beans and forming a unique flavor and available for food.
The method of claim 3,
The bacteria are lactic acid bacteria or Bacillus bacteria.
5. The method of claim 4,
The lactic acid bacteria are Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium animalis Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus gasseri, Lactobacillus delbruecki spp., Lactobacillus delbrueckii spp. Bulgaricus (Lactobacillus bulgaricus), Lactobacillus helveticus (Lactobacillus helveticus), Lactobacillus fermentum, Lactobacillus paracasei, Lactobacillus plantarum (Lactobacillus Lactobacillus plantarum) reuteri), Lactobacillus rhamnosus, Lactobacillus salivarius (L) actobacillus salivarius, Lactococcus lactis, Leuconostoc mesenteroides, Pediococcus cerevisiae, Pediococcus ashdilaccus, Stedococcus lactisoccus The method is selected from the group consisting of Streptococcus lactis, Streptococcus thermophiles and Streptococcus cremoris.
5. The method of claim 4,
Bacillus subtilis (Bacillus subtilis), Bacillus licheniformis (Bacillus licheniformis), Bacillus amyloliquefaciens (Bacillus amyloliquefaciens), Bacillus stearothermophilus (Bacillus stearothermophilus), Bacillus coagulans ), Bacillus longum, Bacillus pumilus, Bacillus brevis, Bacillus circulans and Bacillus polymyxa.
3. The method of claim 2,
The yeast is Saccharomyces cerevisiae, Saccharomyces ellipsoideus, Saccharomyces coreanus, Saccharomyces coreuss, Saccharomyces carlsbergensis, carlsbergensis Saccharomyces pastorianus, Saccharomyces lactis, Saccharomyces rouxii, Schizosaccharomyces pombe, Jigosakaromais major (Zygosaccharomyces major), Hansenula anomala, Bretanomyces bruxellensis, Brettanomyces custersianus, Dekkera anomala, Streptomyma Group consisting of Seteptomyces olivochromogenes and Streptomyces griseus The method selected from.
The method of claim 1,
The fermentation is carried out for 6 to 168 hours at a temperature of 20 to 45 ℃ and a relative humidity of 95 to 99%.
The method of claim 1,
Wherein said fermentation is carried out using a fermenter.
The method of claim 1,
The method further comprises the step of adding cellulase to the green beans during the fermentation.
The method of claim 10,
The content of the cellulase is 0.05 to 5% (w / w) based on the green bean weight.
The method of claim 1,
Further comprising the step of washing said green beans prior to fermenting said green beans or endothelial green beans.
The method of claim 1,
Sterilizing the green beans prior to fermenting the green beans or endothelial green beans.
The method of claim 13,
Wherein said sterilization is carried out by a method selected from the group consisting of ultraviolet light, ethanol treatment, heat treatment and combinations thereof.
The method of claim 1,
After the fermentation is finished, further comprising the step of quickly drying by washing or heating the surface to prevent further fermentation of the fermented green beans.
Fermented beans produced by the method of any one of claims 1 to 15.
A method for producing a fermented coffee extract, comprising the step of extracting hot water from the fermented beans of claim 16.
18. The method of claim 17,
Method for producing a fermented coffee extract further comprising the step of roasting the fermented coffee beans and grinding the roasted fermented coffee beans before the hot water extraction.
Fermented coffee extract prepared by the method of claim 18.

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