JP7244273B2 - Method for producing rooibos tea beverage - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a rooibos tea beverage containing a rooibos extract.

In recent years, rooibos tea obtained by extracting rooibos, which is a kind of herb native to South Africa, has been widely consumed in Japan from the viewpoint of health. It is especially preferred by women seeking health and beauty benefits.

Rooibos is a plant that originally grew only in a very limited area, such as Cedarberg, Western Cave, South Africa. . In fact, rooibos extract contains a large amount of polyphenols such as flavonoids and tannins, vitamin C, inorganic salts, and the like.

Examining prior art documents related to rooibos, for example, Patent Document 1 discloses a method for producing rooibos tea extract, which is characterized by extracting rooibos tea with water within a range of pH exceeding 7 and not exceeding pH 12. is disclosed.
In addition, Patent Document 1 examines the temperature and amount of solvent in the extraction of rooibos tea with respect to the extraction method of rooibos, and reports that in the range of 23 to 90 ° C., the higher the temperature, the easier it is to extract polyphenols. Document 1 discloses that this is done.

JP-A-7-155133

Int. J. Food. Sci. Technol., 25, No.3, 339-343, 1990

As described above, in recent years, due to the growing health consciousness, more and more people are actively ingesting healthy ingredients from food and drink. Among beverages in particular, packaged beverages (so-called RTDs) are widely used, and many products that appeal to health such as foods for specified health uses and foods with function claims are being marketed. However, although consumers can ingest the desired health ingredients at any time, they want to ingest them in their favorite drinking scenes as much as possible.

Beverages are most easily consumed in daily life, and one of the drinking scenes desired by consumers is during a meal. This is because, for example, it becomes easier to eat and to feel the taste of the meal by drinking it with meals.
Most of the beverages containing health-promoting ingredients contain abundant health-promoting ingredients, but often have a unique flavor. For example, it may have a strong astringent taste, or may have a conspicuous smell or taste specific to health ingredients. Although such beverages can be drunk alone without seeking taste like medicines and supplements, it is very difficult to taste and drink them with meals.

As described above, a beverage using rooibos extract (also referred to as “rooibos tea”) cannot be said to have a flavor suitable for a drink during meals. Specifically, rooibos tea is suitable for drinking alone like herbal tea due to its unique aroma, or as a thirst-quenching drink due to its refreshing feeling, but it is not suitable for drinking with meals. In some cases, it becomes difficult to feel the taste of meals, and after drinking, the rooibos tea's unique aroma and refreshing feeling remain in the oral cavity, which may impair the taste of meals itself.

In Japan, the center of food is Japanese food. While green tea has been consumed since ancient times as a beverage with a delicate flavor suitable for Japanese cuisine, there is a potential for rooibos tea, which does not contain caffeine and contains healthy ingredients different from green tea, to be drunk during meals. There are also needs. As described above, there is a need for a new packaged rooibos tea beverage that does not interfere with the taste of meals and has a refreshing aftertaste.

Therefore, the present invention provides a rooibos tea beverage that is suitable as a beverage during a meal, specifically, a rooibos tea beverage that has a good aftertaste and a rooibos-like aroma, but also has moderate astringency and richness that make the mouth feel refreshed. It is intended to provide

The present invention is a method for producing a rooibos tea beverage using plucked fresh rooibos leaves as a raw material,
After the plucked fresh rooibos leaves are dried and fermented to obtain dry fermented rooibos tea leaves (referred to as the “drying step”), the dried fermented rooibos tea leaves are extracted in a solvent to obtain an extract (referred to as the “extraction step”). It is characterized by
In the drying step, the aspalathin content of the dried rooibos fermented tea leaves is 0.08 to 0.50% by mass, and
A method for producing a rooibos tea beverage is proposed, which is characterized by extracting so that the polyphenol content in the rooibos tea beverage is 300 to 500 ppm.

The present invention also provides a method for improving the aftertaste of a rooibos tea beverage using plucked fresh rooibos leaves as a raw material,
After the plucked fresh rooibos leaves are dried and fermented to obtain dry fermented rooibos tea leaves (referred to as the “drying step”), the dried fermented rooibos tea leaves are extracted in a solvent to obtain an extract (referred to as the “extraction step”). It is characterized by
In the drying step, the aspalathin content of the dried rooibos fermented tea leaves is 0.08 to 0.50% by mass, and
A method for improving the aftertaste of a rooibos tea beverage, which is characterized by extracting so that the polyphenol content in the rooibos tea beverage is 300 to 500 ppm, is proposed.

In the method for producing a rooibos tea beverage and the method for improving aftertaste proposed by the present invention, the asparatine content in the dried fermented rooibos tea leaves is adjusted to a specific amount by a drying step of drying the plucked fresh rooibos leaves, and the subsequent extraction is performed. By adjusting the polyphenol content in the rooibos tea beverage to a specific amount by the process, it is possible to improve the aftertaste of the rooibos tea beverage and have a moderate astringency that refreshes the mouth while having a scent like rooibos. It is possible to provide a rooibos tea beverage with a rich taste, that is, a rooibos tea beverage that is well compatible with meals.

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiments described below.

<<This rooibos tea beverage manufacturing method>>
A method for producing a rooibos tea beverage according to an example of the embodiment of the present invention (referred to as "this method for producing rooibos tea beverage") comprises fermenting picked fresh rooibos leaves while drying them to obtain dried fermented rooibos tea leaves ("drying step ”), a production method characterized by extracting the dried rooibos fermented tea leaves in a solvent to obtain an extract (extraction step).
The present rooibos tea beverage production method may include other steps or treatments as long as it includes the above-described drying step and extraction step.

<raw materials>
Rooibos raw materials include raw leaves or branches of rooibos (scientific name: Aspalathus linearis or Aspalathus Cedarbergensis) (referred to as “rooibos leaves”).

<Drying process>
In the drying step, it is preferable to ferment the plucked fresh rooibos leaves while drying them, and to obtain dry fermented rooibos tea leaves by heat treatment to stop the fermentation at an appropriate time.

In the drying step, it is preferable to adjust the aspalathin content in the dry fermented rooibos tea leaves to 0.08 to 0.50% by mass.
The degree of fermentation of fresh rooibos leaves can be determined using the content of aspalathin contained in the fresh rooibos leaves as an index. That is, it is known that as the fermentation of fresh rooibos leaves progresses, the content of aspalathin decreases. From this point of view, if the aspalathin content in the dried fermented rooibos tea leaves is 0.50% by mass or less, it is preferable because the greenish chemical odor peculiar to rooibos is reduced, and it is preferably 0.08% by mass or more. It is preferable because it has a honey-like sweetness.
Therefore, in the drying process, it is preferable to adjust the aspalathin content in the dried fermented rooibos tea leaves to 0.08 to 0.50% by mass, especially 0.10% by mass or more or 0.48% by mass. In the following, it is more preferable to adjust the content to 0.12% by mass or more or 0.40% by mass or less.

In order to adjust the content of aspalathin contained in dry fermented rooibos tea leaves within the above range, the degree of fermentation of fresh rooibos leaves may be adjusted. It is preferable to adjust the time from picking to inactivation of fermentation enzymes.

Drying methods for fresh rooibos leaves include sun drying, hot air drying, fluidized bed drying, and low temperature drying.

The drying temperature and the drying period, in other words, the fermentation period, are not particularly limited as long as the content of aspalathin contained in the dried fermented rooibos tea leaves can be adjusted to the above range. However, as a standard of the drying temperature, 10 to 60°C, especially 20°C or higher or 50°C or lower, and especially 30°C or higher or 45°C or lower can be mentioned. In addition, as a guideline for the drying period, 5 to 30 hours, preferably 8 hours or more or 24 hours or less, or 10 hours or more or 20 hours or less can be mentioned.

In order to deactivate the fermentation enzyme, the rooibos leaves may be heated to a predetermined temperature, for example, 80°C or higher, preferably 90°C or higher.
As the heat treatment means at this time, any means such as contact with steam or hot air, movement in a heating furnace, or the like can be adopted.

<Pressure treatment>
If necessary, it is preferable to pressurize fresh rooibos leaves or dried rooibos fermented tea leaves. By pressurizing fresh rooibos leaves or dried fermented rooibos tea leaves to destroy the cells of the fresh rooibos leaves, it is possible to promote the progress of fermentation and improve the extractability.
This pressure treatment may be inserted at any stage prior to the extraction process. For example, it may be inserted after picking and before fermentation (drying process), during fermentation (drying process), or after fermentation (drying process) and before extraction. Among them, from the viewpoint of promotion of fermentation, it is preferable to pressurize after picking and before fermentation (drying step).

The pressure treatment at this time is not particularly limited as long as it is a treatment capable of destroying the cells of fresh rooibos leaves or dry fermented rooibos tea leaves. For example, it is kneaded as in the rough tea process of green tea, pressurized using a leaf beater, rough kneader and kneading machine, and the CTC machine and rotor van machine used in the rough tea process of black tea production. It can be used to pressurize. Moreover, it may be crushed with a press machine, a mincing machine, or the like, or may be pressurized by adopting other means.

The pressure applied to fresh rooibos leaves or dry fermented rooibos tea leaves during pressure treatment is preferably 10 g/cm ² to 100 kg/cm ² , more preferably 50 kg/cm ² or more or 100 kg/cm ² or less.

<Extraction process>
The dry fermented rooibos tea leaves obtained as described above, that is, the rooibos tea leaves that have been moderately fermented and whose fermentation enzymes have been deactivated, are optionally crushed or pulverized and extracted in a solvent to obtain an extract. You should try to get it.

As the method for extracting the dried fermented rooibos tea leaves, any extraction method can be adopted as long as it is a method of obtaining an extract by contacting the dried fermented rooibos tea leaves with a solvent. Examples thereof include batch extraction, column extraction, kneader extraction, dripper extraction and other extraction methods.

The solvent used for extraction is preferably water. As water, tap water, ion-exchanged water, distilled water, or the like can be used.
The extraction temperature, that is, the temperature of the solvent is preferably 40 to 100°C, more preferably 55°C or higher or 90°C or lower, and more preferably 60°C or higher or 80°C or lower.
The extraction time is preferably 2 minutes to 60 minutes, more preferably 5 minutes or more or 50 minutes or less, more preferably 8 minutes or more or 40 minutes or less.
The amount of the solvent used for extraction is preferably changed as appropriate depending on the state of the dried rooibos fermented tea leaves, etc. For example, it is preferably about 2 to 100 parts by mass based on 1 part by mass of raw tea leaves (converted to dry product). Among them, it is more preferably about 5 parts by mass or more or 50 parts by mass or less.

After the extraction, it is preferable to separate the extract from the tea leaf residue by solid-liquid separation means.
At this time, solid-liquid separation means may include various filtration methods, centrifugal separation, and the like. For example, a method of performing solid-liquid separation with a centrifugal separator after performing filtration using flannel, stainless mesh, or the like can be mentioned.

In the extraction step, it is preferable to adjust the extraction conditions so that the polyphenol content in the rooibos tea beverage is 300-500 ppm.
If the polyphenol content in the rooibos tea beverage is adjusted to 300 ppm or more, a full-bodied taste can be felt, and if it is adjusted to 500 ppm or less, the astringency does not last, which is preferable.
From this point of view, it is preferable to adjust the extraction conditions so that the polyphenol content in the rooibos tea beverage is 300 to 500 ppm, especially 320 ppm or more or 480 ppm or less, especially 340 ppm or more or 460 ppm or less. Adjusting is even more preferable.

In order to adjust the polyphenol content in the rooibos tea beverage to the above range, extraction conditions such as extraction temperature can be adjusted. Moreover, you may adjust by concentrating and diluting the obtained extract. However, it is not limited to this method.
The polyphenol content in the rooibos tea beverage changes during the sterilization process, but since the sterilization conditions are constant depending on the type of beverage, it is difficult to adjust the polyphenol content in the rooibos tea beverage in the sterilization process. be. Therefore, it is preferable to adjust the extraction conditions in the extraction step in order to adjust the polyphenol content in the rooibos tea beverage.

In the present invention, the "polyphenol content" is the total amount of compounds having two or more phenolic hydroxyl groups in the molecule, and is a value calculated by the Folin-Denis method using tannic acid as a standard. The polyphenols include, for example, tannin, aspalathin, orientin and the like.

<Mixing process>
The extract obtained by extraction as described above is preferably diluted as it is or if necessary, and if necessary, various components used in ordinary beverages are added, and the pH is adjusted as necessary.
For example, antioxidants such as ascorbic acid and sodium ascorbate, fragrances, pH adjusters such as sodium bicarbonate, emulsifiers, preservatives, sweeteners, coloring agents, thickeners, seasonings, and enhancers, if necessary. Additives such as agents and dietary fiber may be blended alone or in combination.

The soluble solid content (Brix) of the extract is preferably 0.07 to 0.50 in terms of drinking concentration, especially 0.09 or more or 0.40 or less, among them 0.11 or more or 0.32 or less is more preferable.
At this time, Brix can be measured using a technique known to those skilled in the art, for example, it can be measured using a commercially available optical refractometer.

The pH of the extract is preferably 4.00 to 6.20, more preferably 4.20 or more or 6.00 or less, and more preferably 4.50 or more or 5.80 or less.
At this time, the pH can be measured using a method known to those skilled in the art, for example, a method of measuring with a commercially available pH meter.

The above-mentioned "dietary fiber" is an indigestible component contained in food that is not digested by human digestive enzymes, and is the total amount of water-soluble dietary fiber and insoluble dietary fiber. The dietary fiber contained in the rooibos tea beverage includes dietary fiber as an additive and dietary fiber as a tea leaf-containing component obtained by extracting rooibos tea leaves.

Examples of the water-soluble dietary fiber include pectin, guar bean enzyme hydrolyzate, glucomannan, β-glucan, polydextrose, fructan, inulin, gum arabic, maltitol, psyllium, indigestible oligosaccharide, indigestible dextrin, and agarose. , sodium alginate, carrageenan, fucoidan, porphyran, laminaran and the like.
Examples of the insoluble dietary fiber include cellulose, hemicellulose, lignin, chitin and chitosan.

In the present rooibos tea beverage production method, it is preferable to adjust the dietary fiber content in the rooibos tea beverage to 100 to 15000 ppm, among which 110 ppm or more or 13000 ppm or less, among which 120 ppm or more or 10000 ppm or less is more preferably adjusted to .
In order to adjust the dietary fiber content as described above, dietary fiber may be added to the extract if necessary. Adding dietary fiber not only increases the amount of healthy ingredients, but also makes it easier to drink, such as suppressing bitterness.

<Filling process>
The extract prepared as described above is preferably sterilized or packaged by a conventional method.

Examples of filling containers include metal cans, paper packs, and plastic bottles. For example, when a plastic container is used, the oxygen permeation amount (cc/day/500 mL bottle) of the container at 25° C. and 55% RH is preferably 0.01 to 0.10, especially 0.015 or more, or 0.08 or less, more preferably 0.02 or more or 0.06 or less.

Regarding sterilization and filling, specifically, for example, in the case of canned beverages, heat sterilization such as retort sterilization may be performed after container filling, and in the case of PET bottled beverages, container filling may be performed after UHT sterilization. good.

<<explanation of words>>
In the present invention, when described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably Y It also includes the meaning of "less than".
In addition, when described as "X or more" (X is an arbitrary number), it includes the meaning of "preferably greater than X" unless otherwise specified, and is described as "Y or less" (Y is an arbitrary number). If not otherwise specified, it also includes the meaning of "preferably smaller than Y".

EXAMPLES The present invention will be specifically described below with reference to examples. However, the present invention is by no means limited to the following examples.
The measurement methods and evaluation methods used in the present invention are as follows.

<Example 1>
The plucked fresh rooibos leaves are subjected to pressure treatment for 30 seconds with a roughing machine, then dried in a constant temperature and humidity chamber at a temperature of 32 ° C and a humidity of 30% for 24 hours. The dried rooibos fermented tea leaves were obtained by heating as described above to deactivate the enzyme.

10 g of the obtained dried fermented rooibos tea leaves were placed in 200 ml of water (50° C.) and immersed for 25 minutes to obtain an extract.
The extract was filtered through a stainless mesh (80 mesh), and the filtrate was cooled to 10°C and centrifuged to separate the tea leaf residue and the extract to obtain a fermented rooibos extract.

After adding to the obtained fermented rooibos extract so that the ascorbic acid content in the rooibos tea beverage becomes 300 ppm when it is diluted, and adjusting the pH to 6.1 by adding sodium bicarbonate, Pure water was added to make up to 1000 ml to obtain a rooibos tea beverage.
The resulting rooibos tea beverage is subjected to high-temperature short-time sterilization (137.5°C, 30 seconds), cooled to 25°C, filled in a PET bottle in an aseptic environment, and tightly sealed with a plastic cap. A packaged rooibos tea beverage (sample) was obtained. Moreover, the amount of dietary fiber at this time was 113 ppm.
The "amount used" in the table means the amount of dry fermented rooibos tea leaves with respect to the amount of rooibos tea beverage after being diluted to 1000 ml.

<Example 2-5, Example 7-13 and Comparative Example 1-8>
A packaged rooibos tea beverage (sample) was obtained in the same manner as in Example 1 above, except that the production conditions were changed to those shown in Tables 1 and 2.
At this time, the dietary fiber content of Examples 2-5 and 7-13 was 107 ppm to 176 ppm, and the dietary fiber content of Comparative Example 1-8 was 64 ppm to 198 ppm.

<Example 6>
The plucked fresh rooibos leaves are subjected to pressure treatment for 30 seconds with a roughing machine, then dried in a constant temperature and humidity chamber at a temperature of 32 ° C and a humidity of 30% for 24 hours. The dried rooibos fermented tea leaves were obtained by heating as described above to deactivate the enzyme.

10 g of the obtained dried fermented rooibos tea leaves were placed in 200 ml of water (50° C.) and immersed for 25 minutes to obtain an extract.
The extract was filtered through a stainless mesh (80 mesh), and the filtrate was cooled to 10°C and centrifuged to separate the tea leaf residue and the extract to obtain a fermented rooibos extract.

When the obtained fermented rooibos extract was diluted, the ascorbic acid content in the rooibos tea beverage was 300 ppm, and the dietary fiber (Fibersol 2, manufactured by Matsutani Chemical Industry Co., Ltd.) content in the rooibos tea beverage was 15000 ppm. After adding sodium bicarbonate to adjust the pH to 6.1, pure water was added to make up to 1000 ml to obtain a rooibos tea beverage.
The resulting rooibos tea beverage is subjected to high-temperature short-time sterilization (137.5°C, 30 seconds), cooled to 25°C, filled in a PET bottle in an aseptic environment, and tightly sealed with a plastic cap. A packaged rooibos tea beverage (sample) was obtained.

<Comparative Example 9>
The plucked fresh rooibos leaves were subjected to pressure treatment for 30 seconds with a roughing machine, then dried in a constant temperature and humidity room at a temperature of 32 ° C and a humidity of 30% for 8.5 hours. The dried rooibos fermented tea leaves were obtained by heating to 90° C. or higher to deactivate the enzyme.

12 g of the resulting dried fermented rooibos tea leaves were placed in 200 ml of water (50° C.) and immersed for 25 minutes to obtain an extract.
The extract was filtered through a stainless mesh (80 mesh), and the filtrate was cooled to 10°C and centrifuged to separate the tea leaf residue and the extract to obtain a fermented rooibos extract.

When the obtained fermented rooibos extract was diluted, the ascorbic acid content in the rooibos tea beverage was 300 ppm, and the dietary fiber (Fibersol 2, manufactured by Matsutani Chemical Industry Co., Ltd.) content in the rooibos tea beverage was 20000 ppm. and then sodium bicarbonate was added to adjust the pH to 6.1, then pure water was added to make up to 1000 ml to obtain a rooibos tea beverage.
The resulting rooibos tea beverage is subjected to high-temperature short-time sterilization (137.5°C, 30 seconds), cooled to 25°C, filled in a PET bottle in an aseptic environment, and tightly sealed with a plastic cap. A packaged rooibos tea beverage (sample) was obtained. Moreover, the amount of dietary fiber at this time was 113 ppm.

<Method for quantifying aspalathin content in dried rooibos fermented tea leaves>
A known quantification method (Journal of Foodcomposition and Analysis 55 (2017) 20-29) was partially modified to quantify aspalathin in the sample. 0.1 g of rooibos tea leaves pulverized with a ball mill (MM400, manufactured by Retsch, conditions: frequency 25/s, 30 seconds) was collected in a 50 ml volumetric flask, and 50% acetonitrile (0.1% phosphoric acid) was added to make 50 ml. It was made up to volume and extracted for 30 minutes at room temperature. During this period, the mixture was mixed by inversion once every 15 minutes. The supernatant was filtered through a filter and quantified by HPLC under the following conditions.

HPLC conditions:
Column: Agilent Technologies Poroshell 120 SB-C12 2.7 μm (4.6 mm × 150 mm)
Guard column: Agilent Technologies ZORBAX SB-C18 5 μm (4.6 mm × 12.5 mm)
A solution: 0.1% formic acid aqueous solution B solution: acetonitrile Flow rate: 1.0 ml / min
Temperature: 44.5°C
Detection: 288nm
Gradient: 0min
(A88%) → 25min (A85%)

<Measurement of polyphenol content in rooibos tea beverage>
The amount of polyphenols was quantified by the Folin-Dennis method (see “Explanation by Practitioner of Analysis: Key Points of Component Analysis for Nutrition Labeling” and “Explanation of Manual for Analysis of Standard Tables of Food Composition in Japan 5th Edition by Practitioner of Analysis”).

<Measurement of dietary fiber content in extract>
Dietary fiber was calculated by totaling values measured by the following enzyme-weight method and enzyme-HPLC method.

(enzyme-gravimetric method)
1. Take 5 g of the test drink (including concentrated ones as necessary) in two 500 ml tall beakers, add 0.08 mol / L phosphate buffer (pH 6.0) to make 50 ml, Termamil (120 L, Novozymes) 0.1 ml of the mixture was added, and the mixture was shaken and incubated in a boiling water bath for about 30 minutes, and then allowed to cool.
2. Next, the pH was adjusted to 7.5±0.1 with 10 ml of 0.275 mol/L sodium hydroxide solution, and 0.1 ml of protease (P-5380, manufactured by Sigma) solution (50 mg/ml phosphate buffer) was added. After incubating with shaking at 60° C. for 30 minutes, the mixture was allowed to cool.
3. Subsequently, the pH was adjusted to 4.3±0.3 with 10 ml of 0.325 mol/L hydrochloric acid, and 0.1 ml of aminoglucosidase (A-9913, manufactured by Sigma) was added and incubated at 60° C. for 30 minutes with shaking. , was allowed to cool.
4. Next, dilute up to 4 times the volume of 95% ethanol (60° C.), leave at room temperature for 1 hour,
The generated precipitate was suction-filtered through a 2G2 glass filter (preliminarily formed with 1 g of celite to form a filter layer) to separate the residue and the filtrate (the filtrate was used for the enzymatic-HPLC method).
5. This residue was washed with 20 ml of 78% ethanol three times, two or more times with 10 ml of 95% ethanol, two or more times with 10 ml of acetone, and, if necessary, diethyl ether (the wash solution was used for the enzymatic-HPLC method as well as the filtrate). ) and dried at 105° C. overnight.
6. Two samples were subjected to constant weight measurement (R1, R2), protein (P) was obtained by the Kjeldahl method with a coefficient of 6.25, then incinerated at 525 ° C. for 5 hours, and ash content (A) (%) was measured. .

Dietary fiber (g/100 g) was determined by the enzyme-gravimetric method using the numerical values obtained by the above operations.
Enzyme-gravimetric dietary fiber (g/100g) =
(R×(1-(P+A)/100/2)-B)/S×100
R: Weight of residue (mean value, (R1+R2)/2, mg)
P: protein in residue (%)
A: Ash content in residue (%)
S: sample collection amount (mean value, mg)

B: blank (mg)
B=r×(1−(p+a)/100)
R: Weight of blank residue (mean value, mg)
p: protein (%) in blank residue
a: Ash content in blank residue (%)

(Enzyme-HPLC method)
1. The above filtrate and washing solution were mixed, glycerin (internal standard substance) was added, and ethanol was evaporated.
2. Next, the volume was adjusted to 100 ml with water, and 50 ml was sampled and desalted by column chromatography under the following conditions.
Column: glass tube, 20φmm x 300mm
Filler: ion exchange resin (Amberlite IRA-67 type (OH type) and Amberlite 200CT (H type) (manufactured by Organo) mixed at a volume ratio of 1:1), 50 ml
Eluent: water, 150 ml
Flow rate: 50ml/h
3. Next, the column eluate was evaporated (concentrated), adjusted to 10 ml with water, and filtered through a 0.45 μm membrane filter.
4. Next, the filtrate was subjected to HPLC under the following conditions to measure dietary fiber-equivalent peaks (a group of peaks eluted at the same time as or earlier than maltotriose (trisaccharide)) and glycerin areas (PF and PG). Dietary fiber (g/100 g) was determined by the enzyme-HPLC method using the numerical values obtained by the above operations.

Dietary fiber by enzyme-HPLC method (g/100g) = PF/PG x f x G/S x 100
PF: Dietary fiber equivalent peak area in HPLC method PG: Glycerin peak area in HPLC method f: Peak sensitivity ratio of glycerin and glucose under the HPLC conditions used (0.821)
G: Amount of glycerin added (mg)
S: Sample collection amount (mg)

For the concentrated test beverages, a numerical value converted from the concentration ratio was obtained.

<Sensory evaluation test>
For the containerized rooibos tea beverages (samples) obtained in Examples and Comparative Examples, 10 panelists engaged in the development and production of rooibos tea beverages were selected and conducted based on the following evaluation method. , the most common evaluation was adopted, and the results of the consultation were also adopted for the overall evaluation.

First, the panelists were asked in advance about the container-packed rooibos tea beverages (samples) obtained in each of the examples and comparative examples, which had the least "pure chemical odor" and "astringent taste" and had "honey They were asked to select the sample that gave them the most “sweet aroma” and “kokumi”. As a result, Example 5 was selected as a control.
After that, panelists were asked to discuss the control's "greenish chemical odor,""honey-likesweetness,""astringenttaste," and "rich taste." A shared recognition of odor, honey-like sweetness, astringency, and full-bodied taste was established.
Then, for each of the packaged rooibos tea beverages (samples) obtained in Examples and Comparative Examples, after eating a bite (20 g) of white rice, two types, one at room temperature and the other heated to 55 ° C., were given to each panelist. After taking a bite of the white rice again, they were scored based on the following criteria, and the highest score was shown in the table.

(Medicinal odor with a grassy odor)
1: Very strong: The greenish chemical odor peculiar to rooibos is very strong, and it greatly affects the flavor of food.
2: Strong: Rooibos has a strong herbaceous chemical odor, which strongly affects the flavor of food.
3: Normal: There is a greenish chemical odor peculiar to rooibos, which affects the flavor of food.
4: Slightly weak: A slightly grassy chemical odor peculiar to rooibos is felt, but it does not affect the flavor of the meal.
5: Weak... Almost no rooibos-specific grassy chemical odor is felt, and there is no effect on the flavor of meals.

(honey-like sweetness)
1: Very weak...Does not have honey-like sweet scent peculiar to rooibos and does not affect meals.
2: Weak: It has a slightly honey-like sweet scent peculiar to rooibos, but does not affect meals.
3: Normal: Has honey-like sweet aroma peculiar to rooibos, but does not affect meals.
4: Slightly strong: It has a strong honey-like sweet scent peculiar to rooibos, and enhances the flavor of meals.
5: Strong: Has a very strong honey-like sweet scent peculiar to rooibos, and enhances the flavor of meals well.

(astringency)
1: Very strong: The astringent aftertaste is very strong, and it has a very strong effect on the taste of food.
2: Strong: Astringent aftertaste is strong, and strongly influences the taste of meals.
3: Normal: Astringent aftertaste is felt, affecting the taste of the meal.
4: Slightly weak...Slightly astringent aftertaste is felt, but does not affect the taste of the meal.
5: Weak... Almost no astringent aftertaste, and no effect on the taste of food.

(rich taste)
1: Very weak … Very weak richness, and the mouth does not feel refreshed at all.
2: Weak…The richness is weak and the oral cavity does not feel refreshed.
3: Normal: A rich taste is felt, but the oral cavity does not feel refreshed.
4: Slightly strong: The richness is slightly strong, and the mouth feels refreshed after drinking.
5: Strong: Feels a strong richness, and the mouth feels very refreshed after drinking.

(comprehensive evaluation)
◎ (very good): Very good with food: 37-40 points ○ (good): Suitable with food: 33-36 points △ (poor): Slightly unsuitable with food: 29-32 points × (very poor): Not suitable for meals: 28 points or less, at least one 1 or 2.

(Discussion)
As shown in Table 1, by adjusting the amount of aspalathin in the dried rooibos fermented tea raw material by drying and adjusting the polyphenol concentration at the time of drinking by extracting, the odor and astringency peculiar to rooibos are suppressed, and the sweet aroma and The full-bodied taste has improved. This effect was also observed in the case of hot drinking.
When the same test was performed with other foods such as bread instead of white rice, the same results as with white rice were obtained.

Claims (5)

A method for producing a rooibos tea beverage using plucked fresh rooibos leaves as a raw material,
After fermenting the plucked fresh rooibos leaves at 10 to 60 ° C. for 5 to 30 hours while drying to obtain dry fermented rooibos tea leaves (referred to as a “drying step”), the dry fermented rooibos tea leaves are added to a solvent at a temperature of 40 to 100 ° C. Characterized by extracting in a time of 2 to 60 minutes to obtain an extract (referred to as an “extraction step”),
In the drying step, the aspalathin content of the dried rooibos fermented tea leaves is 0.08 to 0.50% by mass, and
A method for producing a rooibos tea beverage, characterized by extracting so that the polyphenol content in the rooibos tea beverage is 300 to 500 ppm. The method for producing a rooibos tea beverage according to claim 1, wherein the dietary fiber content in the rooibos tea beverage is 100 to 15000 ppm. The method for producing a rooibos tea beverage according to claim 1 or 2, wherein the tea leaves are pressurized before the extraction step. The method for producing a rooibos tea beverage according to any one of claims 1 to 3, wherein the temperature of the solvent is 50 to 98°C in the extraction step. A method for improving the aftertaste of a rooibos tea beverage using plucked fresh rooibos leaves as a raw material, comprising:
After fermenting the plucked fresh rooibos leaves at 10 to 60 ° C. for 5 to 30 hours while drying to obtain dry fermented rooibos tea leaves (referred to as a “drying step”), the dry fermented rooibos tea leaves are added to a solvent at a temperature of 40 to 100 ° C. Characterized by extracting in a time of 2 to 60 minutes to obtain an extract (referred to as an “extraction step”),
In the drying step, the aspalathin content of the dried rooibos fermented tea leaves is 0.08 to 0.50% by mass, and
A method for improving the aftertaste of a rooibos tea beverage, which comprises extracting the rooibos tea beverage so that the content of polyphenols in the rooibos tea beverage is 300 to 500 ppm.