Method for fermenting cacao beans and method for producing chocolate

Abstract

This method for fermenting cacao beans includes a fermentation step in which anaerobic fermentation of cacao beans is performed for a prescribed period in a non liquid-permeable container.

Description

Fermentation method for cocoa beans and chocolate manufacturing method

[0001] The present invention relates to a method for fermenting cocoa beans and a method for producing chocolate.

[0002] In conventional cocoa bean fermentation, cocoa beans are removed from the cocoa pod and placed in a breathable container, such as a wooden box, to begin fermentation. Immediately after removal from the cocoa pod, sugar-containing pulp surrounds the cocoa beans. Liquid (pulp liquor) seeps out of the pulp, covering the beans for several days, allowing fermentation to proceed under anaerobic conditions. During this process, yeast produces ethanol from the sugars in the pulp via alcoholic fermentation, and floral and fruity aromas, such as esters and alcohols, are produced. Over the course of several days, the pulp liquor gradually leaks out of the container, and oxygen enters the container as the pulp decomposes. This oxygen influx reduces the yeast population, activating the proliferation of acetic acid bacteria, which then become dominant. Acetic acid bacteria produce acetic acid from alcohol through acetic acid fermentation, which strongly influences the sourness of chocolate. During acetic acid fermentation, the temperature inside the container (fermentation temperature) can reach or exceed 45°C. If fermentation continues after acetic acid fermentation, it may progress beyond the optimal fermentation period and progress to over-fermentation. During this period, the growth of aerobic bacteria, including Bacillus species, becomes dominant, resulting in the production of off-flavors.

[0003] Patent Document 1 discloses a technique for processing cocoa beans, in which the cocoa beans are placed in an airtight container with a lock to prevent gas from entering, and fermented under anaerobic conditions with the gas inside the container removed by vacuum, thereby producing chocolate with a better flavor than when a wooden box is used as the container.

[0004] International Publication No. 2014 / 127130

[0005] However, the technology described in Patent Document 1 requires the cost and effort of procuring a specific sealed container, and the cost and effort of preparing equipment to remove gas from the container.

[0006] To produce large amounts of esters and alcohols produced by yeast, it is necessary to maintain the viable yeast cell count for a long period of time. However, with conventional cocoa bean fermentation methods, oxygen flows in as fermentation progresses, and the growth of acetic acid bacteria becomes dominant within a few days, making this difficult to achieve. Therefore, a fermentation method that maintains the viable yeast cell count for a long period of time and produces large amounts of esters and alcohols is needed. Furthermore, with conventional fermentation methods, there is a problem that over-fermentation occurs over a long period of time, resulting in an increase in off-flavors. Therefore, a fermentation method that can be carried out over a long period of time but progresses more slowly than conventional fermentation and produces less off-flavors is needed.

[0007] Therefore, an object of the present invention is to provide a fermentation method that is unlikely to lead to over-fermentation even during long-term fermentation and that can produce cocoa beans with high levels of esters and alcohols produced by yeast.

[0008] In order to achieve the above object, the present invention provides the following method for fermenting cocoa beans and method for producing chocolate.

[0009] [1] A method for fermenting cocoa beans, comprising a fermentation step of anaerobic fermentation of cocoa beans in a liquid-impermeable container for a predetermined period of time. [2] The method according to [1], wherein, in the fermentation step, the oxygen concentration in the fermentation environment is 0.5% or more and 5.0% or less, and the fluctuation range of the oxygen concentration is 4.5% or less. [3] The method according to [2], wherein, in the fermentation step, the temperature in the fermentation environment is 25.5°C or more and 33.0°C or less, and the fluctuation range of the temperature is 7°C or less. [4] The method according to any one of [1] to [3], wherein the predetermined period is 48 hours or more and 240 hours or less. [5] A method for producing chocolate, comprising producing chocolate using fermented cocoa beans obtained by the fermentation method according to any one of [1] to [4] as an ingredient.

[0010] According to the present invention, it is possible to provide a method for fermenting cocoa beans that suppresses the sourness and off-flavors of chocolate and increases the alcohols and esters.

[0011] FIG. 1 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 2 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 3 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 4 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 5 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 6 is a diagram showing the results of a test example relating to one embodiment of the present disclosure. FIG. 7 is a diagram showing the results of a test example relating to one embodiment of the present disclosure.

[0012] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these and various modifications are possible without departing from the gist of the present invention.

[0013] In the embodiments of the present invention, the expression X (numerical value) to Y (numerical value) means X or more and Y or less unless otherwise specified.

[0014] 1. Method for Fermenting Cocoa Beans A method for fermenting cocoa beans according to an embodiment of the present invention (hereinafter referred to as "the present embodiment") includes a fermentation step in which anaerobic fermentation of cocoa beans is carried out in a liquid-impermeable container.

[0015] (Raw Materials Used) The cacao beans used in this embodiment are not limited by origin, variety, etc. Cacao beans of Trinitario, Criollo, Forastero, etc., originating from Central and South America, West Africa, Southeast Asia, Oceania, etc., can be used. Cacao beans of a suitable origin and variety can be appropriately selected depending on the purpose of use, for example, the purpose of chocolate production and the desired flavor.

[0016] (Fermentation step) The method for fermenting cocoa beans of this embodiment includes a fermentation step (hereinafter also referred to as "anaerobic fermentation step") in which cocoa beans are filled into a liquid-impermeable container and anaerobically fermented in the liquid-impermeable container for a predetermined period of time.

[0017] The liquid-impermeable container may be any container that is liquid-impermeable at the contact points between the cocoa beans, pulp, and pulp liquid packed therein. For example, a container that does not have holes or gaps that would allow the passage of liquid in the pulp liquid at the contact points can be used. The material of the container is not particularly limited, and examples include metal containers such as buckets, plastic containers, glass containers, and ceramic containers.

[0018] In one embodiment, in the fermentation process, cocoa beans are filled into a liquid-impermeable container and a portion of the filled cocoa beans is covered from above with a predetermined means. Examples of the predetermined means used for covering include cloth, sheet, film, and a pre-made lid (such as a drop lid). The material of the covering means may be, for example, a resin such as polyvinyl chloride, polyvinylidene chloride, or polyolefin (polyethylene or polypropylene), a metal such as aluminum, or a plant leaf. One type of covering means may be used alone, or two or more types may be used in combination.

[0019] In one embodiment, when the cocoa beans are filled into a container, the cocoa beans filled in the container may be maintained in a state open to the atmosphere. The state in which the cocoa beans are open to the atmosphere can be achieved, for example, by not sealing the container filled with the cocoa beans. More specifically, for example, the state in which the cocoa beans are open to the atmosphere can be achieved by providing a vent that communicates with the outside in the container filled with the cocoa beans. Alternatively, if the container has an opening, the state in which the cocoa beans are open to the atmosphere can be achieved by opening the opening to the atmosphere. Furthermore, the state in which the cocoa beans are open to the atmosphere can be a state in which at least a portion of the cocoa beans is open to the atmosphere. With a portion of the cocoa beans open to the atmosphere, another portion of the cocoa beans may be covered from above by a predetermined means.

[0020] In this disclosure, "putting cocoa beans into a container" may be used interchangeably with "filling cocoa beans into a container."

[0021] In the present disclosure, "anaerobic fermentation" of cocoa beans refers to fermentation in a state in which the cocoa beans are immersed in pulp and / or pulp liquid, in which the cocoa beans containing the pulp are placed in a liquid-impermeable container and fermented. Even when a portion of the cocoa beans, pulp, pulp liquid, etc. packed in the liquid-impermeable container is exposed to the atmosphere and comes into contact with oxygen, while the remaining portion (the interior of the fermented product) does not come into contact with oxygen, this also falls under the category of "anaerobic fermentation" in the present disclosure. The oxygen concentration in the fermentation environment may be the predetermined oxygen concentration described in this embodiment.

[0022] In the anaerobic fermentation process, the fermented product is not necessarily left standing, but it is particularly desirable to avoid stirring to improve the degree of mixing of the fermented product or to supply oxygen to the fermented product. By avoiding these operations, the inflow of oxygen is suppressed, and an increase in the oxygen concentration in the fermentation environment can be suppressed. This suppresses the growth of aerobic bacteria, the progression of acetic acid fermentation and subsequent processes, and the increase in temperature.

[0023] In this disclosure, "stirring" and "agitation" may be used interchangeably.

[0024] Examples of stirring operations for improving the degree of mixing of the fermented product or for supplying oxygen to the fermented product include manual stirring operations or mechanical stirring operations performed regularly or irregularly, bubble stirring operations, aeration, shaking stirring operations, operations for transferring the fermented product from a liquid-impermeable container to a liquid-permeable container at the time of or after the stirring operation, and operations for removing pulp and / or pulp liquid at the time of or after the stirring operation.

[0025] In this disclosure, the term "fermentation environment" refers to the interior of a fermentation vessel containing cocoa beans, pulp, and pulp liquor. The pulp is the flesh that covers the cocoa beans and is approximately 80% water, with other components including sugars, pectin, citric acid, etc. The pulp liquor refers to the liquid that seeps out from the pulp.

[0026] In one embodiment, the fermentation process employs a predetermined oxygen concentration in the fermentation environment. For example, the predetermined oxygen concentration in the fermentation environment may be 0.3% or more, 0.4% or more, 0.5% or more, 0.6% or more, 0.7% or more, or 0.8% or more. Also, for example, the oxygen concentration in the fermentation environment may be 5.5% or less, 5.4% or less, 5.3% or less, 5.2% or less, 5.1% or less, 5.0% or less, 4.9% or less, 4.8% or less, 4.7% or less, 4.6% or less, 4.5% or less, 4.4% or less, 4.3% or less, or 4.2% or less.

[0027] The predetermined oxygen concentration in the fermentation environment is preferably the oxygen concentration throughout the entire fermentation period.

[0028] In one embodiment, the anaerobic fermentation process employs a predetermined range of change in oxygen concentration in the fermentation environment (hereinafter simply referred to as "oxygen concentration change"). For example, the predetermined oxygen concentration change in the fermentation environment may be 5.0% or less, 4.5% or less, 4.4% or less, 4.3% or less, 4.2% or less, 4.1% or less, 4.0% or less, or 3.9% or less. The lower limit of the predetermined oxygen concentration change may be 0.0%, i.e., there may be no oxygen concentration change.

[0029] The predetermined change in oxygen concentration in the fermentation environment is preferably the range of change in oxygen concentration over the entire anaerobic fermentation period.

[0030] In one embodiment, the anaerobic fermentation process employs a predetermined temperature in the fermentation environment. For example, the temperature in the fermentation environment may be 26.0°C or higher, 26.1°C or higher, 26.2°C or higher, 26.3°C or higher, 26.4°C or higher, 26.5°C or higher, or 26.6°C or higher. Alternatively, for example, the temperature in the fermentation environment may be 33.2°C or lower, 33.0°C or lower, 32.9°C or lower, 32.8°C or lower, 32.7°C or lower, 32.6°C or lower, 32.5°C or lower, 32.4°C or lower, 32.3°C or lower, 32.2°C or lower, 32.1°C or lower, 32.0°C or lower, or 31.9°C or lower.

[0031] The predetermined temperature in the fermentation environment is preferably the temperature throughout the entire fermentation period.

[0032] As shown in Figure 6, yeast prefers and grows in an environment of 25.0 to 32.0°C. Therefore, by maintaining these temperatures during anaerobic fermentation, it is possible to maintain or increase the viable cell count of yeast that produces the fermented product, and to delay the progress of fermentation after acetic acid fermentation.

[0033] In one embodiment, the anaerobic fermentation process employs a predetermined temperature change range in the fermentation environment (hereinafter simply referred to as "predetermined temperature change"). For example, the predetermined temperature change in the fermentation environment may be 7.0°C or less, 6.5°C or less, 6.0°C or less, 5.5°C or less, 5.0°C or less, 4.9°C or less, 4.8°C or less, 4.6°C or less, 4.4°C or less, 4.2°C or less, or 4.0°C or less. The lower limit of the predetermined temperature change may be 0.0°C, i.e., there may be no temperature change.

[0034] The above-mentioned predetermined temperature change is preferably the temperature change over the entire anaerobic fermentation period.

[0035] In one embodiment, the fermentation step may maintain the cocoa beans in an open state to the atmosphere. Fermentation with the cocoa beans in an open state to the atmosphere can be achieved, for example, by carrying out fermentation without sealing the container filled with the cocoa beans. More specifically, the fermentation can be achieved, for example, by carrying out fermentation in a state where the cocoa beans are filled in a container provided with a vent opening communicating with the outside. Alternatively, if the container has an opening, the fermentation can be achieved by opening the opening to the atmosphere.

[0036] In the present disclosure, the state in which the cocoa beans are exposed to the atmosphere during the fermentation process may be a state in which at least a portion of the cocoa beans are exposed to the atmosphere, or a state in which a portion of the cocoa beans is exposed to the atmosphere and another portion of the cocoa beans is covered from above by a predetermined means.

[0037] The amount of water in the anaerobic fermentation step is not particularly limited and may be appropriately determined by those skilled in the art.

[0038] In one embodiment, the anaerobic fermentation process may optionally include the addition of pulp liquid or water to prevent exposure of the beans to the atmosphere.

[0039] In one embodiment, the fermentation step employs a predetermined fermentation time, such as 48 hours or more, 60 hours or more, 72 hours or more, 84 hours or more, 96 hours or more, 100 hours or more, 105 hours or more, 110 hours or more, 115 hours or more, 120 hours or more, or 125 hours or more, or 240 hours or less, 235 hours or less, 230 hours or less, 225 hours or less, 220 hours or less, or 215 hours or less.

[0040] In one embodiment, a predetermined live yeast cell count is used in the fermentation step. For example, the live yeast cell count is 1.0 x 10 at 96 hours of fermentation. 6 cfu / mL or more, 1.0×10 5 cfu / mL or more, 1.0×10 4 cfu / mL or more, 1.0×10 3 cfu / mL or more, or 1.0 x 10 2 The live yeast cell count may be, for example, 1.0 × 10 cfu / mL or more at 120 hours of fermentation. 5 cfu / mL or more, 1.0×10 4 cfu / mL or more, 1.0×10 3 cfu / mL or more, 1.0×10 2 cfu / mL or more, or 1.0 x 10 1 The live yeast cell count may be, for example, 1.0 × 10 cfu / mL or more at 144 hours of fermentation. 4 cfu / mL or more, 1.0×10 3 cfu / mL or more, 1.0×10 2 cfu / mL or more, or 1.0 x 10 1 The live yeast cell count may be, for example, 1.0 × 10 cfu / mL or more at the time of 168 hours of fermentation. 3 cfu / mL or more, 1.0×10 2 cfu / mL or more, or 1.0 x 10 1 cfu / mL or more.

[0041] In the method for fermenting cocoa beans of this embodiment, a starter culture for fermentation may be added, or fermentation may be initiated by leaving a container filled with cocoa beans undisturbed with the cocoa beans exposed to the atmosphere without adding a starter culture.

[0042] After fermentation is performed by the anaerobic fermentation step of this embodiment, the fermented product may be optionally transferred to a liquid-permeable vessel to continue aerobic fermentation. The inflow of oxygen promotes acetic acid fermentation, leading to the production of acetic acid. The fermentation time in the liquid-permeable vessel is short, taking into account the progression to an over-fermentation state, such as 24 hours.

[0043] 2. Chocolate Manufacturing Method The chocolate manufacturing method of this embodiment uses the fermented cocoa beans obtained by the fermentation method of this embodiment as a raw material to manufacture chocolate. Apart from using the fermented cocoa beans obtained by the fermentation method of this embodiment as a raw material, chocolate can be manufactured by going through steps such as conching, refining, and tempering in accordance with a known general chocolate manufacturing method.

[0044] The chocolate produced by the chocolate production method of this embodiment has improved chocolate flavor components, such as esters and alcohols, which impart a fruity or floral aroma.

[0045] The chocolate produced by the chocolate production method of this embodiment contains aroma components that serve as an indicator of the suppressed progress of fermentation and aroma components that correspond to suppressed off-flavors. For example, tetramethylpyrazine is an aroma component that increases as fermentation progresses and serves as an indicator of the degree of progress. Also, for example, isovaleric acid corresponds to a type of off-flavor.

[0046] The present invention will now be described with reference to examples, but the present invention is not limited to these examples.

[0047] (Preparation of Fermented Product) Cocoa beans were placed in a liquid-impermeable container with an opening open to the atmosphere. A polyvinyl chloride film (food packaging wrap) was placed over the cocoa beans, and a drop lid was then placed on top of the film. Anaerobic fermentation was carried out in this state for 168 hours to prepare an anaerobic fermented product containing fermented cocoa beans (fermented cocoa beans). Alternatively, cocoa beans (fermented cocoa beans) were placed in a liquid-permeable container made of wood through the opening, and fermentation was carried out for four days to prepare a conventional fermented product. The fermented product was stirred once a day.

[0048] (Measurement of oxygen concentration) The oxygen concentration of the fermentation environment in the prepared fermented product was measured. A DO-5510HA (trade name, manufactured by Mother Tool Co., Ltd.) was used as the measuring device to measure the oxygen concentration. First, the oxygen probe terminal was placed in a location with fresh air for at least 5 minutes, and calibration was completed when the reading reached 20.8% or 20.9%. Next, "measurement of atmospheric oxygen" was selected as the measurement target, and the center of the beans filled inside the container was dug to a depth of approximately 15 cm, and the measuring device was set so that the measuring probe (tip) of the measuring device reached the digging point. The beans removed during digging were placed on top of the probe, and the reading was recorded when the reading stabilized. The results are shown in Figure 1.

[0049] (Temperature Measurement) The temperature of the fermentation environment in the prepared fermented product was measured. A CT311WP (trade name, manufactured by Custom Co., Ltd.) was used as a measuring device to measure the temperature. As with the measurement of oxygen concentration, the measuring device was inserted so that the measuring probe (tip) of the measuring device reached the center of the cocoa beans piled up inside the container. When the value stabilized, the reading was recorded. The results are shown in Figures 2 and 3. A low temperature was maintained during anaerobic fermentation.

[0050] (Measurement of viable yeast cell count 1) (1) During the pre-fermentation process, several cocoa beans were sampled at 0, 24, 72, and 96 hours of normal fermentation, and 0, 24, 72, 120, and 168 hours of anaerobic fermentation. (2) The sampled cocoa beans were weighed, and then an equal amount of water was added. After thorough kneading, 1 mL of the liquid was collected and added to 9 mL of PBS solution for dilution. This dilution procedure was repeated to prepare solutions at any dilution ratio. (3) 1 mL of any diluted solution was added to a Petrifilm YM plate (3M Japan). (4) After 48 hours of incubation, the number of colonies was counted. The results are shown in Figure 4. The yeast count was maintained during anaerobic fermentation.

[0051] (Measurement of Viable Yeast Cell Count 2) (1) Using the same yeast species found during the fermentation of cocoa beans, an appropriate amount of colonies grown on a YPDA agar medium was suspended in 5 mL of YPDA liquid medium and pre-cultured at 25°C for 24 hours. (2) An appropriate amount of the pre-culture was added to 30 mL of fresh YPDA liquid medium, suspended, and pre-cultured at 25°C for 24 hours. (3) The absorbance of the OD660 value of the pre-culture was measured using a spectrophotometer (Hitachi High-Tech U-3900H), and the pre-culture was added to 30 mL of fresh YPDA liquid medium and suspended therein so that the OD660 value after addition was 0.03. (4) The YPDA liquid medium to which the pre-culture had been added was subjected to main culture at temperatures of 25°C, 27°C, 32°C, and 37°C for 96 hours or 144 hours, respectively. (5) After the main culture for a predetermined time, the culture solution was suspended, and 1 mL of the suspension was collected and diluted with 9 mL of PBS. This dilution procedure was repeated to prepare solutions at any dilution ratio. (6) 100 μL of any diluted solution was plated on YPDA agar medium, and the number of colonies was counted after 48 hours of culture. The results are shown in Figure 5.

[0052] (Chocolate Production) (1) The fermented cocoa beans were roasted at 120°C for 30 minutes, and the cocoa husk was removed to obtain cocoa nibs. (2) The obtained cocoa nibs were pulverized in a tabletop blender, and the pulverized material was passed through a roll mill to produce cocoa mass. Sugar, cocoa butter, and an emulsifier were blended with the cocoa mass to produce chocolate.

[0053] (Analysis of Chocolate Components 1) 2.0 g of chocolate was finely chopped and placed in a specially stoppered glass vial, after which aroma analysis was performed using a GC / MS (Agilent Technologies KK). Of the detected aromas, the area values ​​of aromas classified as esters and alcohols were added together and graphed. The results are shown in Figure 6.

[0054] (Analysis of Chocolate Components 2) 2.0 g of chocolate was cut into small pieces and sealed in a specially stoppered glass vial, after which aroma analysis was performed using GC / MS (Agilent Technologies KK). From the detected aromas, tetramethylpyrazine and isovaleric acid were selected, and their respective area values ​​were graphed. The results are shown in Figure 7.

[0055] (Sensory Evaluation of Chocolate) Six trained panelists tasted the chocolates and rated the sourness and floral notes on an 11-point scale ranging from "0 (not noticeable at all)" to "10 (not noticeable at all)" according to the perceived intensity. The results are shown in Figure 8.

[0056] (Quantification of acetic acid in cocoa mass) 100 mg of cocoa mass was added to 100 mL of ultrapure water, heated at 60 ° C. for 30 minutes, and then ultrasonicated for 30 minutes. Subsequently, chloroform was added and the mixture was shaken. The supernatant obtained by centrifugation was passed through an OnGuard IIP solid phase extraction cartridge (Thermo Fisher SCIENTIFIC) washed with 10 mL of ultrapure water, and the first 3 mL was discarded. The subsequent treatment solution was used as the test solution. The test solution was analyzed using an ion chromatograph (Thermo Fisher SCIENTIFIC) to quantify acetic acid. The results are shown in Figure 9. The weight of acetic acid relative to the weight of the cocoa mass is expressed as a percentage.

Claims

1. A method for fermenting cocoa beans, comprising: a fermentation step in which anaerobic fermentation of cocoa beans is carried out in a liquid-impermeable container for a predetermined period of time.

2. The method according to claim 1, wherein the oxygen concentration in the fermentation environment during the fermentation step is 0.5% or more and 5.0% or less, and the variation range of the oxygen concentration is 4.5% or less.

3. The method according to claim 2, wherein the temperature in the fermentation environment during the fermentation step is 25.5°C or higher and 33.0°C or lower, and the temperature change range is 7°C or lower.

4. The method according to any one of claims 1 to 3, wherein the predetermined period is not less than 48 hours and not more than 240 hours.

5. A method for producing chocolate, comprising producing chocolate using fermented cocoa beans obtained by the fermentation method according to any one of claims 1 to 4 as a raw material.

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