Method and apparatus for producing natural vanilla extract

Abstract

This invention provides a method for producing natural vanilla extract that promotes the hydrolysis of glucovaninil to vanillin, thereby improving the quality of vanilla beans. [Solution] The method for producing natural vanilla extract includes a preparation step of preparing an aqueous solution 11 containing an acid or an oxidizing agent, and a fermentation step of irradiating at least the vanilla beans B1 with electromagnetic waves while the vanilla beans B1 are immersed in the aqueous solution 11, and stirring the aqueous solution 11 to cause fermentation.

Description

Technical Field

[0001] The present invention relates to a method for producing a natural vanilla extract that promotes the hydrolysis of glucovanillin to vanillin and improves the quality of vanilla beans, and an apparatus for producing the same.

Background Art

[0002] The high-quality aroma of vanilla ice cream and confectionery is derived from a compound called vanillin obtained from plants of the genus Vanilla in the Orchidaceae family. This vanillin is produced through curing, which means processes such as fermentation, drying, and aging of harvested vanilla beans. Also, before fermentation, an operation called blanching is performed, in which vanilla beans are briefly immersed in hot water, promoting the action of β-glucosidase, which is a degrading enzyme of glucovanillin, a precursor of vanillin. By the action of this activated degrading enzyme, the glycosidic bond of glucovanillin is cleaved (hydrolyzed) to obtain vanillin.

[0003] The amount of vanillin that can be extracted from plants is limited, and it is said that 500 kg of vanilla beans are required per 1 kg of vanillin. Also, the yield of vanilla beans is affected by the weather, and in addition, since the cultivation areas are limited to tropical regions such as Madagascar and Indonesia, price hikes have been a problem in recent years.

[0004] As a technique for extracting a vanilla extract containing such vanillin, for example, the techniques disclosed in Patent Document 1 and Patent Document 2 are known.

[0005] The technique disclosed in Patent Document 1 irradiates ultrasonic waves when producing a vanilla extract by extracting vanilla beans with water and / or a water-soluble organic solvent.

[0006] The technology described in Patent Document 2 comprises a first step of sterilizing the fruit of a vanilla plant or its hybrid species under conditions that do not deactivate enzymes contained in the fruit that have the effect of decomposing precursors of aroma components in the fruit and producing aroma components, and a second step of placing the fruit sterilized in the first step into a breathable container that can be opened and closed at least partially, and curing it in a sterile environment under controlled temperature and light irradiation conditions. [Prior art documents] [Non-patent literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 8-168355 [Patent Document 2] Patent No. 5504497 [Overview of the project] [Problems that the invention aims to solve]

[0008] The technology disclosed in Patent Document 1 involves using ultrasound to transfer the active ingredient into a solvent, thereby efficiently extracting the active ingredient in a short time. However, because the amount of β-glucosidase present in vanilla beans varies, the hydrolysis of glucovaillin is not sufficient, resulting in differences in aroma from bean to bean and inconsistent quality.

[0009] Furthermore, the technology disclosed in Patent Document 2 involves controlling temperature and light irradiation conditions during curing after sterilization of the fruit to suppress the contamination and proliferation of unwanted bacteria and prevent the loss of aromatic components. However, similar to Patent Document 1, the hydrolysis of glucovaillin is not sufficiently carried out, resulting in unstable vanilla bean quality.

[0010] The present invention was made to solve the above problems and aims to provide a method for producing natural vanilla extract and an apparatus for producing the same, which promotes the hydrolysis of glucovaninil to vanillin and improves the quality of vanilla beans. [Means for solving the problem]

[0011] The method for producing natural vanilla extract according to the present invention includes the steps of preparing an aqueous solution containing an acid or an oxidizing agent, and a fermentation step in which vanilla beans are immersed in the aqueous solution, at least the vanilla beans are irradiated with electromagnetic waves, and the aqueous solution is stirred to cause fermentation.

[0012] Thus, in this invention, since the vanilla beans are fermented while immersed in an aqueous solution containing an acid or an oxidizing agent, the glucovannillin contained in the vanilla beans can be hydrolyzed not only by a degrading enzyme but also by the acid or oxidizing agent, allowing a large amount of glucovannillin to be hydrolyzed into vanillin, thereby obtaining high-quality vanilla beans. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of a natural vanilla extract production apparatus according to the first embodiment of the present invention. [Figure 2] This is a flowchart showing a method for producing natural vanilla extract according to the first embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating the flow of a method for producing natural vanilla extract according to the first embodiment of the present invention. [Figure 4] This is a flowchart showing a method for producing natural vanilla extract according to a second embodiment of the present invention. [Figure 5] This is a schematic diagram illustrating the flow of a method for producing natural vanilla extract according to a second embodiment of the present invention. [Figure 6] This is a schematic diagram of a natural vanilla extract production apparatus according to a third embodiment of the present invention. [Figure 7] This is a schematic diagram of a natural vanilla extract production apparatus according to a fourth embodiment of the present invention. [Figure 8] This is a schematic diagram of a natural vanilla extract production apparatus according to a fifth embodiment of the present invention. [Modes for carrying out the invention]

[0014] (First Embodiment of the Present Invention) Hereinafter, a method for producing natural vanilla extract and a production apparatus thereof according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The method for producing natural vanilla extract and the like according to this embodiment involves putting vanilla beans before fermentation into an aqueous solution containing an acid or an oxidizing agent, irradiating the vanilla beans with electromagnetic waves in this state, and stirring them, thereby hydrolyzing a large amount of glucovanillin contained in the vanilla beans into vanillin, and realizing the production of high-quality vanilla beans.

[0015] First, the production apparatus used in the method for producing natural vanilla extract will be described. FIG. 1 is a schematic diagram of the production apparatus for natural vanilla extract according to this embodiment. As shown in FIG. 1, the production apparatus 1 for natural vanilla extract includes a water tank 10 in which an aqueous solution 11 containing an acid or an oxidizing agent is stored, and an irradiation unit 20 that irradiates at least the vanilla beans B1 with electromagnetic waves in a state where the vanilla beans B1 before fermentation, which consist of a sheath and seeds enclosed in the sheath, are immersed in the aqueous solution 11, a stirring unit 30 that stirs the aqueous solution 11 into which the vanilla beans B1 are put, and a control unit 40 that controls the operations of the irradiation unit 20 and the stirring unit 30. In FIG. 1, the case where a microwave irradiation device is used as the irradiation unit 20 and an ultrasonic vibration device is used as the stirring unit 30 is shown.

[0016] Examples of the acid contained in the aqueous solution 11 include acetic acid, hydrogen chloride (hydrochloric acid), sulfuric acid, and the like. Examples of the oxidizing agent contained in the aqueous solution 11 include ozone and the like. When using ozone as the oxidizing agent, ozone gas may be injected from a cylinder or the like into the water (such as distilled water or ion-exchanged water) stored in the water tank 10, or the water may be irradiated with ultraviolet rays to directly generate ozone in the water. If ozone is used as the oxidizing agent, bacteria and viruses can be inactivated, so that the quality degradation and spoilage of vanilla beans can be suppressed.

[0017] The acid or oxidizing agent contained in the water in the water tank 10 may be used alone or in combination of a plurality thereof. Also, the concentration of the aqueous solution 11 containing the acid or oxidizing agent cannot be generally stated because the oxidizing power varies depending on the acid or oxidizing agent used. For example, in the case of an aqueous acetic acid solution, it can be set within the range of 0.1 to 1 mol / L. By setting the acetic acid concentration within this range, the hydrolysis of glucovanillin can proceed effectively, and excessive oxidation and corrosion can be prevented.

[0018] The hydrolysis of glucovanillin using the above acid or oxidizing agent proceeds according to the following reaction formula (1).

[0019]

Chemical formula

[0020] In the hydrolysis of glucovanillin shown in this reaction formula (1), glucovanillin is decomposed into glucose and vanillin using hydrogen ions (H + ) derived from the acid or hydroxyl radicals (·OH) generated by the reaction of an oxidizing agent, for example, ozone and water, as a catalyst.

[0021] The irradiation unit 20 irradiates at least the vanilla beans B1 with electromagnetic waves to heat them, activates β-glucosidase, which is an enzyme for decomposing glucovanillin, and promotes the hydrolysis into vanillin. Examples of the electromagnetic waves irradiated on the vanilla beans B1 include light rays such as infrared rays and radio waves such as microwaves, and microwaves are preferable. When microwaves are used as the electromagnetic waves, the seeds in the sheath can be heated pinpoint, so that damage to the sheath can be reduced. In addition, when microwaves are irradiated on the aqueous solution 11, the movement of hydrogen ions in the aqueous solution 11 can be activated, and hydrolysis can be further promoted. Furthermore, by cutting the glycoside bond of glucovanillin with microwaves, the production of vanillin can be increased. The frequency of the electromagnetic wave is not particularly limited as long as it can promote the hydrolysis of glucovannillin. However, if microwaves are used as the electromagnetic wave, the range is preferably 300 to 3000 MHz, and more preferably 915 to 2450 MHz. By setting the microwave frequency within this range, the rotation of water molecules and the breakdown of hydrogen bonds formed between glucovannillin and water molecules can be effectively promoted, thereby accelerating the hydrolysis reaction. Furthermore, within this frequency range, the energy transfer efficiency of the microwaves is high, allowing for pinpoint action on glycosidic bonds, thus minimizing damage to the vanilla bean B1 pod while promoting the hydrolysis reaction.

[0022] The stirring unit 30 equalizes the temperature rise of the aqueous solution 11 caused by electromagnetic wave irradiation from the irradiation unit 20 by stirring the aqueous solution 11. Means of stirring include ultrasonic dispersion, aeration, and stirring using a magnetic stirring bar. In particular, using ultrasound as a stirring method can prevent violent contact between vanilla bean B1 and large movement (displacement) in the aqueous solution 11, thus preventing damage to the pods, stabilizing quality, and improving commercial value. In addition, the fine vibrations caused by ultrasound make it easier for the aqueous solution 11 containing acid or oxidizing agent to penetrate into the vanilla bean B1, thereby promoting the hydrolysis of glucovaillin. When ultrasonic dispersion is used as a stirring method, the ultrasonic oscillation frequency can be set to, for example, a range of 20 to 40 MHz. By setting the ultrasonic oscillation frequency within this range, appropriate vibrations are applied, enabling uniform stirring of the aqueous solution 11 without damaging the vanilla bean pods B1, and also allowing the aqueous solution 11 to easily penetrate into the vanilla beans. Furthermore, because it activates the vibration of water molecules, it is also effective in promoting the hydrolysis reaction.

[0023] The control unit 40 controls the operation of the irradiation unit 20 and the stirring unit 30. The control unit 40 may control the irradiation unit 20 and the stirring unit 30 to operate continuously, or it may control at least one of the irradiation unit 20 and the stirring unit 30 to operate intermittently, either regularly or irregularly, depending on the temperature of the aqueous solution 11. For example, if the temperature of the aqueous solution 11 exceeds a preset upper temperature limit, the irradiation of electromagnetic waves from the irradiation unit 20 may be temporarily stopped, and stirring by the stirring unit 30 may be performed only. When the temperature of the aqueous solution 11 falls below a preset lower temperature limit, the irradiation of electromagnetic waves may be resumed. Furthermore, the direction of electromagnetic waves irradiated from the irradiation unit 20 may be controlled according to the position and distribution of vanilla beans B1 in the aqueous solution 11 recognized by image recognition or the like. For example, electromagnetic waves may be irradiated only to areas with a high distribution of vanilla beans B1, or the amount and intensity of electromagnetic wave irradiation may be changed for each distribution area according to the distribution of vanilla beans B1.

[0024] Next, a method for producing natural vanilla extract using the manufacturing apparatus 1 will be described. Figure 2 is a flowchart showing the method for producing natural vanilla extract according to this embodiment, and Figure 3 is a schematic diagram illustrating the flow of the method for producing natural vanilla extract according to this embodiment.

[0025] First, as a preliminary step, prepare an aqueous solution 11 containing an acid or oxidizing agent (Step S1) and store it in a tank 10. Next, add the vanilla beans B1 before fermentation to the tank 10 containing the aqueous solution 11 containing the acid or oxidizing agent (Step S2). In steps S1 and S2, as shown in steps A and B of Figure 3, a predetermined amount of harvested vanilla beans B1, which have been washed as appropriate, is prepared to match the size of the water tank 10, and the vanilla beans B1 are gently immersed in the water tank 10 so as not to splash the aqueous solution 11 containing acid or the like outside the water tank 10. The water tank 10 is made of a material that is corrosion-resistant to the acid or oxidizing agent contained in the aqueous solution 11. In addition, in steps S1 and S2, vanilla bean B1 may be added to the water, and then the acid or oxidizing agent may be dissolved in the water.

[0026] Next, the vanilla beans B1 are irradiated with electromagnetic waves from the irradiation unit 20, and the aqueous solution 11 is stirred by the stirring unit 30 to ferment the vanilla beans B1 (step S3, corresponding to step C in Figure 3). The irradiation of the vanilla beans B1 with electromagnetic waves and stirring may be started simultaneously, or stirring may be performed after the irradiation of electromagnetic waves. In step S3, the temperature of the aqueous solution 11 during the fermentation of the vanilla beans B1 may be monitored by a temperature control unit (not shown). In step S3, the green vanilla beans B1 ferment and change color, becoming black, fermented vanilla beans B2, which contain a large amount of vanillin.

[0027] Finally, by recovering the vanilla beans B2 from tank 10 (step S4), vanilla beans B2 containing natural vanilla extract can be produced. The recovered vanilla beans B2 are sorted according to size and other grades and then shipped. In step S4, as shown in steps D and E of Figure 3, the fermented vanilla beans B2 in the aqueous solution 11 are removed from the water tank 10, taking care not to let the acids in the aqueous solution 11 come into contact with the hands. The removed vanilla beans B2 may be subjected to additional treatments such as washing and drying. In particular, if the acids in the aqueous solution 11 are not volatile, the concentration will increase as the vanilla beans B2 dry (water vaporizes), which may damage the pods of the vanilla beans B2, so washing is preferable.

[0028] Thus, by fermenting vanilla bean B1 while it is immersed in an aqueous solution 11 containing an acid or oxidizing agent, the glucovannillin contained in vanilla bean B1 can be hydrolyzed not only by the degrading enzyme but also by the acid or oxidizing agent. This allows a large amount of glucovannillin to be hydrolyzed into vanillin, resulting in high-quality vanilla bean B2.

[0029] (Second embodiment of the present invention) A method for producing natural vanilla extract according to a second embodiment of the present invention will be described with reference to Figures 4 and 5. The method for producing natural vanilla extract according to this embodiment includes a maturation step in which the fermented vanilla beans are heated after the fermentation of the vanilla beans. In this embodiment, any explanations that overlap with those of the first embodiment described above will be omitted.

[0030] Figure 4 is a flowchart showing the method for producing natural vanilla extract according to this embodiment, and Figure 5 is a schematic diagram illustrating the flow of the method for producing natural vanilla extract according to this embodiment. In the method for producing natural vanilla extract according to this embodiment, first, as a preliminary step, an aqueous solution 11 containing an acid or oxidizing agent is prepared (step S11), and this aqueous solution 11 is stored in a water tank 10. Next, vanilla beans B1 before fermentation are added to the water tank 10 in which the aqueous solution 11 containing the acid or oxidizing agent is stored (step S12). In steps S11 and S12, as shown in steps A and B of Figure 5, a predetermined amount of harvested vanilla beans B1, which have been washed as appropriate, is prepared to match the size of the water tank 10, and the vanilla beans B1 are gently immersed in the water tank 10 so that the aqueous solution 11 containing acid, etc., does not splash outside the water tank 10.

[0031] Next, the vanilla beans B1 are irradiated with electromagnetic waves from the irradiation unit 20, and the aqueous solution 11 is stirred by the stirring unit 30 to ferment the vanilla beans B1 (step S13, corresponding to step C in Figure 5). In step S13, the green vanilla beans B1 ferment and change color, becoming black, fermented vanilla beans B2, which contain a large amount of vanillin.

[0032] In step S13, the fermented vanilla beans B2 are removed from the water tank 10, washed and dried as appropriate, and placed in a heating unit 50 such as a constant temperature bath. In this state, the vanilla beans B2 are heated for a predetermined time to mature (step S14). Matured here refers to the further decomposition of glucose, which has been separated from vanillin by the cleavage of the glycosidic bond of glucovaillin in the fermentation process in step S13. Furthermore, during this maturation process and the fermentation process described above, an intermediate product of the hydrolysis of glucovanillin is produced in which the oxygen atom bonded to the carbon atom at position 1 of glucose carries a negative charge. Various compounds contained in vanilla bean B1 and B2 bind to the oxygen atom portion of this intermediate product, resulting in a complex flavor. In step S14, as shown in steps D and E of Figure 5, the fermented vanilla beans B2 in the aqueous solution 11 are removed from the water tank 10 so that the acids in the aqueous solution 11 do not come into contact with the hands, and then placed in the heating unit 50 so that the vanilla beans B2 do not overlap each other. The temperature inside the heating unit 50 is set to, for example, 30 to 50°C. The vanilla beans B2 removed from the heating unit 50 may be subjected to additional processing such as washing and drying.

[0033] Finally, by recovering the vanilla beans B2 from the heating section 50 (step S15, corresponding to step F in Figure 5), vanilla beans B2 containing natural vanilla extract can be produced.

[0034] Thus, by incorporating a maturation process after the fermentation process in which vanilla bean B2 is heated and aged, the glucose separated from vanillin by fermentation is further broken down, resulting in vanilla bean B2 with a complex and deep aroma.

[0035] (Third embodiment of the present invention) A method for producing natural vanilla extract according to a third embodiment of the present invention will be explained with reference to Figure 6. The method for producing natural vanilla extract according to this embodiment involves irradiating at least vanilla beans with electromagnetic waves under reduced pressure. In this embodiment, any explanations that overlap with those of the first embodiment described above will be omitted.

[0036] First, we will describe the manufacturing apparatus used in the method for producing natural vanilla extract. Figure 6 is a schematic diagram of the manufacturing apparatus for natural vanilla extract according to this embodiment. As shown in Figure 6, the natural vanilla extract manufacturing apparatus 1 comprises a sealed water tank 10 in which an aqueous solution 11 containing an acid or oxidizing agent is stored, an irradiation unit 20 installed in the water tank 10 that irradiates vanilla beans B1 before fermentation with electromagnetic waves, a stirring unit 30 that stirs the aqueous solution 11 into which the vanilla beans B1 are added, a pressure adjustment unit 60 that adjusts the pressure inside the sealed water tank 10, and a control unit 40 that controls the operation of the irradiation unit 20, the stirring unit 30, and the pressure adjustment unit 60.

[0037] The pressure adjustment unit 60 adjusts the pressure inside the sealable water tank 10. The pressure adjustment unit 60 can be a conventionally known component, such as a suction pump, piping, valves, etc.

[0038] In the method for producing natural vanilla extract according to this embodiment, in step S3 in which vanilla beans B1 are fermented, the water tank 10 is sealed and the air inside the water tank 10 is sucked out by the pressure adjustment unit 60 to reduce the pressure simultaneously with or before or after the irradiation of electromagnetic waves and stirring of the aqueous solution 11. Since step S3 is carried out under reduced pressure by the pressure adjustment unit 60, the temperature of the aqueous solution 11 does not rise excessively due to the irradiation of electromagnetic waves. Therefore, the fermentation process under reduced pressure can be carried out by irradiation of electromagnetic waves alone without stirring the aqueous solution 11, or by irradiating electromagnetic waves while the degree of stirring of the aqueous solution 11 is suppressed (the movement of the aqueous solution 11 is small).

[0039] Thus, because the fermentation process is carried out under reduced pressure, the temperature of the aqueous solution 11 does not rise excessively due to electromagnetic wave irradiation, preventing the vanilla bean B1 pods from being heated and boiled down, and allowing for the production of high-quality vanilla bean B2. Furthermore, since vanilla bean B1 can be heated for a longer period of time, the production of vanillin can be further increased.

[0040] (Fourth embodiment of the present invention) A method for producing natural vanilla extract according to a fourth embodiment of the present invention will be explained with reference to Figure 7. In this embodiment, the method for producing natural vanilla extract involves stirring the contents of a water tank with a gas containing an acid or oxidizing agent during the vanilla bean fermentation process. In this embodiment, any explanations that overlap with those of the first embodiment described above will be omitted.

[0041] First, we will describe the manufacturing apparatus used in the method for producing natural vanilla extract. Figure 7 is a schematic diagram of the manufacturing apparatus for natural vanilla extract according to this embodiment. As shown in Figure 7, the natural vanilla extract manufacturing apparatus 1 comprises a water tank 10, an irradiation unit 20, a stirring unit 30, and a control unit 40. The stirring unit 30 includes a supply unit 31 capable of supplying gaseous acid or oxidizing agent, and a mixing unit 32 that mixes the gas supplied from the supply unit 31 with a gas that does not react with the acid or oxidizing agent, such as air or nitrogen gas. The mixing ratio of the acid or oxidizing agent to the gas such as air can be adjusted as appropriate, and is adjusted in the range of 0:10 to 10:0 depending on the progress of fermentation of vanilla beans B1 and the concentration of the aqueous solution 11.

[0042] In the method for producing natural vanilla extract according to this embodiment, in step S3 in which vanilla beans B1 are fermented, electromagnetic waves are irradiated from the irradiation unit 20, and a gas containing an acid or oxidizing agent mixed in the mixing unit 32 is sent to the bottom of the water tank 10 via the pipe 70, and supplied to the aqueous solution 11 through the ventilation hole 71 provided at the end of the pipe 70 to aerate. This aeration of the gas containing the acid or oxidizing agent stirs the vanilla beans B1.

[0043] In the method for producing natural vanilla extract according to the first embodiment described above, an aqueous solution 11 containing an acid or oxidizing agent was prepared, and vanilla beans B1 before fermentation were added to this aqueous solution 11. Then, electromagnetic waves were irradiated from the irradiation unit 20, and the aqueous solution 11 was stirred by the stirring unit 30. However, in this embodiment, a gas containing an acid or oxidizing agent is supplied from the stirring unit 30, and the mixture is aerated and stirred with this gas. Therefore, it is also possible to add vanilla beans B1 to water that does not contain an acid or oxidizing agent, irradiate with electromagnetic waves from the irradiation unit 20, supply an acid or oxidizing agent to the water from the stirring unit 30 to dissolve it, and stir with the resulting airflow to ferment the vanilla beans B1.

[0044] Thus, in the fermentation process, the aqueous solution 11 is aerated and stirred with a gas containing an acid or oxidizing agent. This allows for the appropriate supply of acid or oxidizing agent to the aqueous solution 11, replenishing the acid or oxidizing agent that has been used up by hydrolysis, thereby promoting the hydrolysis of glucovannillin and shortening the fermentation time.

[0045] (Fifth embodiment of the present invention) A method for producing natural vanilla extract according to a fifth embodiment of the present invention will be explained with reference to Figure 8. In this embodiment, the method for producing natural vanilla extract involves spraying an aqueous solution containing an acid or an oxidizing agent onto vanilla beans during the vanilla bean fermentation process and then irradiating them with electromagnetic waves. In this embodiment, any explanations that overlap with those of the first embodiment described above will be omitted.

[0046] First, we will describe the manufacturing apparatus used in the method for producing natural vanilla extract. Figure 8 is a schematic diagram of the manufacturing apparatus for natural vanilla extract according to this embodiment. As shown in Figure 8, the natural vanilla extract manufacturing apparatus 1 comprises a spraying unit 80 that sprays an aqueous solution 11 containing an acid or oxidizing agent, an irradiation unit 20 that irradiates vanilla beans B1 before fermentation with electromagnetic waves, and a control unit 40 that controls the operation of the irradiation unit 20 and the stirring unit 30.

[0047] The spray unit 80 sprays an aqueous solution 11 containing an acid or oxidizing agent towards the vanilla beans B1 in either a liquid or gaseous state. When spraying the aqueous solution 11 in a gaseous state from the spray unit 80, the vanilla beans B1 may be placed in a heated, sealed space to maintain the gaseous state of the aqueous solution 11. When fermentation of the vanilla beans B1 is carried out in a heated, sealed space, electromagnetic wave irradiation from the irradiation unit 20 may be suppressed.

[0048] In the method for producing natural vanilla extract according to this embodiment, in steps S2 and S3 of fermenting vanilla beans B1, instead of stirring the aqueous solution 11 with the stirring unit 30, the vanilla beans B1 placed on the workbench T are sprayed with the aqueous solution 11 containing an acid or oxidizing agent from the spray unit 80, and the vanilla beans B1 are irradiated with electromagnetic waves from the irradiation unit 20 to ferment the vanilla beans B1. In the example shown in Figure 8, the vanilla beans B1 are placed on the workbench T. However, to improve the spraying efficiency of the aqueous solution 11, the vanilla beans B1 may be suspended while the aqueous solution 11 is sprayed. The vanilla beans B2, which have been fermented in this manner, are then washed, dried, and collected as appropriate.

[0049] In this way, by spraying vanilla bean B1 with an aqueous solution 11 containing an acid or oxidizing agent in a liquid or gaseous state, and irradiating vanilla bean B1 with electromagnetic waves to induce fermentation, the glucovannillin contained in vanilla bean B1 can be hydrolyzed not only by degrading enzymes but also by the acid or oxidizing agent, thereby hydrolyzing a large amount of glucovannillin to vanillin and obtaining high-quality vanilla bean B2. In particular, when an aqueous solution 11 containing an acid or oxidizing agent is sprayed onto vanilla beans B1 in a gaseous state, the acid or oxidizing agent can be sprayed in a smaller particle state, allowing the acid or oxidizing agent to act effectively on glucovaillin.

[0050] Furthermore, the above embodiments can be used in combination as appropriate. [Explanation of symbols]

[0051] 1 Manufacturing equipment 10 aquariums 11 Aqueous solution 20 Irradiation area 30 Stirring section 31 Supply section 32 Mixing section 40 Control Unit 50 Heating section 60 Pressure regulating section 70 Piping 71 Ventilation holes 80 Spray section B1, B2 vanilla beans T Workbench

Claims

1. A preparation step of preparing an aqueous solution containing an acid or oxidizing agent, A method for producing natural vanilla extract, characterized by comprising a fermentation step of immersing vanilla beans in the aqueous solution, irradiating at least the vanilla beans with electromagnetic waves, and stirring the aqueous solution to cause fermentation.

2. In the method for producing natural vanilla extract according to claim 1, A method for producing natural vanilla extract, characterized by including a maturation step in which the fermented vanilla beans are heated and matured for a predetermined time after the fermentation step.

3. In the method for producing natural vanilla extract according to claim 1, The method for producing natural vanilla extract is characterized in that the fermentation step involves irradiating at least the vanilla beans with electromagnetic waves under reduced pressure.

4. In the method for producing natural vanilla extract according to claim 1, The fermentation step is characterized by aerating and stirring the aqueous solution in which the vanilla beans have been added with a gas containing the acid or the oxidizing agent.

5. With vanilla beans immersed in an aqueous solution containing an acid or an oxidizing agent, the system includes an irradiation unit that irradiates at least the vanilla beans with electromagnetic waves, An apparatus for producing natural vanilla extract, characterized by comprising a stirring unit for stirring the aqueous solution.

6. In the apparatus for producing natural vanilla extract according to claim 5, A natural vanilla extract manufacturing apparatus comprising a heating unit for heating and maturing the vanilla beans that have been fermented by irradiating them with electromagnetic waves by the irradiation unit and stirring the aqueous solution by the stirring unit.

7. In the apparatus for producing natural vanilla extract according to claim 5, A natural vanilla extract manufacturing apparatus characterized by comprising a pressure adjustment unit capable of adjusting the pressure in a water tank in which the aqueous solution is stored.

8. A preparation step of preparing an aqueous solution containing an acid or oxidizing agent, A method for producing natural vanilla extract, characterized by comprising a fermentation step of spraying the aqueous solution onto vanilla beans in a liquid or gaseous state, and irradiating at least the vanilla beans with electromagnetic waves to cause fermentation.

Images