JP7085174B1 - Manufacturing method of anaerobic fermented tea - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an anaerobic fermented tea having improved acidity and less odor. A method for producing anaerobic fermented tea, which comprises steaming tea leaves and then fermenting the tea leaves in an anaerobic environment. The anaerobic environment is preferably vacuum, and the pH of the tea leaf juice after fermenting the tea leaves is preferably 4.0 to 5.0. [Selection diagram] FIG. 10

Description

The present invention relates to a method for producing anaerobic fermented tea, and more particularly to a method for producing anaerobic fermented tea having improved acidity and less odor.

There are various types of tea depending on the manufacturing method. Examples include green tea, which is unfermented tea, oolong tea, which is semi-fermented tea, black tea, which is fermented tea, and Puer tea, which is post-fermented tea. Among them, post-fermented tea is preferred because it has a better aroma than other teas.

Such post-fermented teas include Awa evening tea (post-fermented tea after simmering) and Goishicha (registered trademark, two-stage post-fermented tea after steaming). Awa evening tea is made by hand-picking, boiling heat, kneading, barrel pickling, lactic acid fermentation, and sun-drying. Goishicha (registered trademark) is made by hand-picking, steaming, primary fermentation (aerobic fermentation with mold), barrel pickling, secondary fermentation (lactic acid fermentation), and sun-drying.

Further, Patent Document 1 describes a method for producing a substance that inhibits the saccharification reaction of a protein for the purpose of effectively inhibiting the saccharification reaction of the protein and producing a safe substance, and aerobic fermentation of tea leaves. A method including a step of anaerobically fermenting to obtain fermented tea, a step of extracting the fermented tea with an aqueous solvent to obtain an aqueous solvent extract, and a step of extracting the aqueous solvent extract with an ester solvent , Disclosed.

Japanese Unexamined Patent Publication No. 2019-99529

However, traditional post-boiled fermented tea cannot be continuously produced because it is boiled in a kettle and killed. Further, in the boiling heat step, the tea leaf components are easily eluted in the broth, and the flavor components, nutritional components, and lactic acid bacteria essential for post-fermentation are reduced.

Further, although the traditional two-step steaming fermented tea and the method described in Patent Document 1 are used to kill blue by steaming heat, they use a steaming tub and cannot be continuously produced. In addition, since the tissue of tea leaves is destroyed by the primary fermentation with mold derived from the production area without kneading, it is difficult to produce post-fermented tea by the same manufacturing method in other areas.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for producing anaerobic fermented tea having improved acidity and less odor.

As a result of diligent studies to solve the above problems, the present inventors have found that the above object can be achieved by lactic acid fermentation of tea leaves in an anaerobic environment, and have completed the present invention. ..

That is, the method for producing anaerobic fermented tea of the present invention is characterized in that the tea leaves are steamed and then fermented in an anaerobic environment.

Further, in the method for producing anaerobic fermented tea of the present invention, it is preferable that the anaerobic environment is a vacuum.

Further, in the method for producing anaerobic fermented tea of the present invention, the pH of the squeezed liquid of tea leaves after fermenting the tea leaves is preferably 4.0 to 5.0.

According to the present invention, it is possible to provide a method for producing an anaerobic fermented tea having improved acidity and less odor.

It is a photograph showing tea leaves. It is a photograph showing the picking with a riding picking machine. It is a photograph showing a steam locomotive. It is a photograph which shows the tea leaf discharge part after steaming (steaming heat). It is a photograph showing an aluminum vapor deposition bag compatible with vacuum and decompression. This is a photograph of tea leaves packed in an aluminum vapor deposition bag. It is a photograph showing the vacuum packaging process. It is a photograph showing a stationary state for fermentation. It is a photograph showing the sun drying. It is a photograph showing the sun drying. It is a photograph showing anaerobic fermented tea. It is a photograph of a lithographic image of a fermented leaf / dried sample for measuring the number of bacteria. It is a photograph of a colony image (MRS agar medium) of a fermented leaf / dried sample and an example of a Gram-stained elephant. It is a photograph of a colony image (MRS agar medium) of a fermented leaf / dried sample and another example of a Gram-stained elephant.

Hereinafter, the method for producing the anaerobic fermented tea of the present invention will be specifically described.
The method for producing anaerobic fermented tea of the present invention is characterized in that the tea leaves are steamed (heated) and then fermented in an anaerobic environment. Further, the method for producing anaerobic fermented tea of the present invention is characterized in that the tea leaves are steamed, kneaded, and then fermented in an anaerobic environment. Steamed tea leaves are placed in a closed container and lactic acid fermented in an anaerobic environment. In addition, by placing the tea leaves in an anaerobic environment, spoilage caused by aerobic bacteria and molds in the early stage of fermentation is suppressed, and lactic acid fermentation is performed by the lactic acid bacteria inside the tea leaves. In summer, tea with strong acidity and fruity aroma can be obtained in about 2 to 3 weeks.

In addition, in traditional post-boiled fermented tea, the components of tea leaves are easily eluted in the broth during the boiling process, and lactic acid bacteria are also eluted in the broth, and the lactic acid bacteria are further reduced by heating the broth. In the present invention, there is no loss of various nutritional components inside the tea leaves due to the heat of steam, and more lactic acid bacteria are present.

Further, in the present invention, the anaerobic environment is not limited as long as the effect of the present invention is obtained, and for example, an anaerobic gas such as nitrogen gas can be encapsulated, but an anaerobic gas such as nitrogen gas is used. It is most preferable to create a vacuum without encapsulation. As a result, unlike traditional post-boiled fermented tea, there is no need for broth, so steam locomotives commonly used in the tea industry can be used, and mechanical picking can be selected. In addition, continuous and efficient plucking and bleaching are possible. Furthermore, in the conventional traditional manufacturing method, a barrel-derived flavor and a broth-derived flavor are added to form a complex flavor. In particular, the upper part of the barrel may be directly exposed to the air, and unintended fermentation by microorganisms other than yeast and lactic acid bacteria may occur. In addition, even inside the barrel, if air remains between the tea leaves during pickling, the action of lactic acid bacteria weakens, causing quality deterioration. On the other hand, in the case of vacuum fermentation as in the present invention, since the inside of the container or bag is evenly placed in an anaerobic state, the flavor produced by pure anaerobic fermentation is the main. Therefore, the sourness is felt stronger than that of the traditional post-fermented tea, and the aroma is fruit-like, and the post-fermented tea completely different from the conventional traditional production method can be obtained.

Further, in the method for producing anaerobic fermented tea of the present invention, the pH of the squeezed liquid of tea leaves after fermenting the tea leaves is preferably 4.0 to 5.0, preferably 4.0 to 4.5. Is more preferable. As a result, the fermented state of tea leaves can be confirmed, the acidity is improved, and high-quality anaerobic fermented tea can be obtained.

Further, in the present invention, the tea leaves are tea leaves that have not been heat-treated after being plucked, and include not only tea leaves immediately after plucking but also tea leaves that have been plucked and stored in a refrigerator, freezer or the like. Further, the tea leaves may contain any part such as sprout, mature leaf, stem, etc., and the content ratio thereof is not limited, but the sprout, adult leaf, etc. are the main. In addition, tea (camellia sinenis, evergreen tree of the family of camellia) leaves include autumn-winter bancha, cold tea, spring bancha, first tea, second tea, third tea, fourth tea, etc., depending on the time of plucking. Tea and spring bancha are preferable.

FIG. 1 is a photograph showing tea leaves, and FIG. 2 is a photograph showing picking with a riding picking machine. As shown in FIGS. 1 and 2, fully grown tea leaves are plucked with a riding plucking machine. If the stem is hardened, pluck it in several batches at a height of about 10 cm. In the figure, the picking is performed by a riding picking machine, but the picking means is not particularly limited, and hand picking or the like may be used. As such a riding type plucking machine, for example, a riding type plucking machine KJ8C-SJ (trade name), a riding type plucking machine KJ10C-SJ (R) (trade name) manufactured by Kawasaki Kiko Co., Ltd. can be used.

FIG. 3 is a photograph showing a band steamer, and FIG. 4 is a photograph showing a tea leaf discharging portion after steaming (steaming heat). As shown in FIG. 3, the plucked tea leaves are killed with a band steam locomotive. In the case of hardened tea leaves, the steaming time is about 5 minutes. In addition, as shown in FIG. 4, the parts that come into contact with the tea leaves on the band steam locomotive, the conveyor after discharging, and the like are sufficiently disinfected and sterilized. This is because there is a risk of putrefaction due to the adhesion of anaerobic bacteria and mold. Then, the obtained tea leaves can be kneaded, but they do not have to be kneaded. Although steaming is performed by a band steam locomotive in the figure, the steaming means is not particularly limited, and for example, a rotary steam locomotive or the like can be used. Examples of such a band steamer include a band steamer 250K (trade name) to 1600K (trade name) manufactured by Miyamura Iron Works Co., Ltd., a simple band steamer 200K type (product name), and a simple band steamer. A steam locomotive 300K type (trade name) or the like can be used.

FIG. 5 is a photograph showing an aluminum vapor deposition bag compatible with vacuum and decompression, FIG. 6 is a photograph of an aluminum vapor deposition bag filled with tea leaves, and FIG. 7 is a photograph showing a vacuum packaging process. As shown in FIGS. 5 to 7, the tea leaves are put in a vacuum-packed aluminum vapor-deposited bag having a light-shielding property and vacuum-packed. At that time, anaerobic gas such as nitrogen gas is not enclosed. Further, for example, in the case of a 25 kg standard aluminum vapor deposition bag, it is preferable that the amount of tea leaves to be put is about 8 kg for autumn tea leaves and about 5 kg for cold tea leaves. In the figure, an aluminum vapor deposition bag compatible with vacuum / depressurization is used, but the container is not particularly limited as long as it is a container compatible with vacuum / depressurization, and for example, a can, a drum, or the like can also be used. Further, when an anaerobic gas is used to create an anaerobic environment in a closed container such as a can or a drum, it is necessary to add weight to the tea leaves.

FIG. 8 is a photograph showing a stationary state for fermentation. As shown in FIG. 8, a vacuum aluminum vapor deposition bag containing tea leaves is allowed to stand at room temperature (15 to 35 ° C.) for lactic acid fermentation. The fermentation period is about 3 to 4 weeks in the summer and 6 to 8 weeks in the winter, and if the temperature is properly controlled using a fermentation chamber or the like, fermentation will be completed in a shorter period of time. .. Anaerobic bacteria and the like decrease due to the decrease in tannin and pH contained in tea leaves. In addition, after the middle stage of fermentation, the pH of the tea leaf juice is lowered to 4.0 to 5.0 by lactic acid fermentation.

As shown in FIGS. 9 and 10, which are photographs showing sun-drying, FIGS. 9 and 10 are lactic acid fermented, and a sufficient acidity (pH 4.0 to 4.5) is felt. By the way, open it and dry the tea leaves in the sun. Although it is dried in the sun in the figure, the drying method is not particularly limited as long as it can be dried, and for example, a dryer or the like can be used.

FIG. 11 is a photograph showing anaerobic fermented tea. The anaerobic fermented tea after drying in the sun had improved acidity and less odor.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example)
The fully grown autumn tea leaves were plucked by a passenger plucking machine, and the plucked autumn tea leaves were killed by the band steamer shown in FIG. The steaming time is 5 minutes. In addition, the steam locomotive and the conveyor after discharge were sufficiently disinfected and sterilized. Next, the obtained tea leaves were placed in a vacuum-packed aluminum vapor-deposited bag having a light-shielding property and vacuum-packed. The capacity was 8 kg of autumn tea leaves in a 25 kg standard aluminum vapor deposition bag. Then, a vacuum aluminum vapor deposition bag containing autumn tea leaves was allowed to stand at room temperature (15 to 35 ° C.) for lactic acid fermentation. The fermentation period is 3-4 weeks due to the summer season. The pH of the squeezed juice of the obtained tea leaves was in the range of 4.0 to 5.0. Further, the tea leaves were dried in the sun to produce anaerobic fermented tea. The obtained lactic acid (anaerobic) fermented tea had improved acidity and less odor.

(Experimental example)
Leaves after plucking (fresh leaves), leaves after steaming (steamed leaves), leaves after kneading (kneaded leaves), leaves fermented for 3 weeks after steaming (steamed leaves / fermentation), fermented for 3 weeks after kneading The following viable cell counts are applied to the leaves that have been kneaded (kneaded leaves / fermented), the leaves that have been fermented for 3 weeks after being steamed and undried (fermented leaves / undried), and the leaves that have been kneaded and then fermented and dried for 3 weeks (fermented leaves / dried). The inspection and the microbial isolation test were performed, and the results are shown in Table 1 below.

(Live cell count test)
5 g of each sample was weighed, 10 mL of sterile physiological saline was added, and the crushed and suspended product was smeared and cultured by the following method using the undiluted solution, and the viable cell count was examined.
・ Medium: MRS Broth (Oxoid, GBR) + agar ・ Culture temperature: 30 ° C
・ Culture time: 5 days ・ Diluted solution: Physiological saline ・ Dilution ratio: Undiluted solution ~ 10 ⁶ times diluted ・ Measurement method: Diluted plate method (0.1 mL surface smear CFU method)
Automatic dilution / smearing device, easySpiralDilute (interscience, FRA)
・ Number of smears: 3 of the same dilution ・ Other conditions: Anaerobic culture, Aneropouch Kenki System (Mitsubishi Gas Chemical Company, Inc.)
・ Colony observation: Stereomicroscope SMZ800N (Nikon Corporation)
-Judgment: Colonies grown on the plate at an appropriate dilution stage were measured according to the difference in colony morphology.

(Microbial separation test)
Microorganisms were separated from the bacterial count measuring plate used in the above viable cell count test and the culture medium cultured in MRS Broth (Oxoid, GBR). Gram stain and catalase tests were performed on the isolates, and Gram-positive and catalase-negative bacteria were isolated as lactic acid bacteria.
-Medium: MRS Bros (Oxoid, GBR) + agar mold isolate is also cultured in Potato Dextrose Agar (Becton Dickinson, USA, pH 5.6 ± 0.2) (PDA). USA) + culture on agar (YM agar) ・ Culture temperature: 30 ° C
・ Culture time: 5 days ・ Diluted solution: Physiological saline ・ Dilution ratio: Stock solution ~ 10 ⁶ times diluted ・ Separation method: Diluted plate method (0.1 mL surface smear CFU method)
Automatic dilution / smearing device, easySpiralDilute (interscience, FRA)
・ Number of smears: 3 of the same dilution ・ Other conditions: Anaerobic culture, Aneropouch Kenki System (Mitsubishi Gas Chemical Company, Inc.)
・ Colony observation: Stereomicroscope SMZ800N (Nikon Corporation)
<Gram stain>
Gram stainability and cell morphology were observed using:
-Gram stain: Fiber G "Nissui" (Nissui Pharmaceutical Co., Ltd.)
・ Microscope: Optical microscope BX50F4 (Olympus Corporation)
<Catalase test>
A catalase test was performed using the following.
・ Catalase test: 3% hydrogen peroxide solution ・ Judgment: Negative if no bubbles are generated

(Table 1)

FIG. 12 is a photograph of a flat plate image for measuring the number of bacteria in a fermented leaf / dried sample, and FIG. 13 is a photograph of a colony image (MRS agar medium) of a fermented leaf / dried sample and an example of a Gram-stained elephant. Is a colony image (MRS agar medium) of a fermented leaf / dried sample and a photograph of another example of a Gram-stained elephant. From the results of Table 1 and FIGS. 12 to 14, it can be seen that by producing the anaerobic fermented tea by the production method of the present invention, only the lactic acid bacteria of the anaerobic fermented tea are increased, and general bacteria, molds and the like are killed. all right. From this, it was confirmed that an anaerobic fermented tea with improved acidity and less odor can be obtained.

Claims (2)

After steaming the tea leaves, ferment the tea leaves in an anaerobic environment.
A method for producing anaerobic fermented tea , wherein the anaerobic environment is a vacuum . The method for producing anaerobic fermented tea according to claim 1, wherein the pH of the tea leaf juice after fermenting the tea leaves is 4.0 to 5.0.

Images