JP2003304811A - Method for producing green tea polyphenol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain dry tea leaf polyphenol containing a plenty of catechin and maintaining inherited taste of a beverage to which the polyphenol is added and provide the beverage added with the polyphenol, maintaining taste of the beverage as a base, presenting no foreign odor after heat sterilization and reduced in bitter taste. <P>SOLUTION: The method for producing green tea leaf polyphenol is to extract green tea leaves with water at <10°C in a first extraction treatment, subsequently extract them with warm water at ≥50°C in an after extraction and dry the extracted solution. A method for producing the beverage by adding the green tea leaf polyphenol obtained by the method is provided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a dry green tea polyphenol which is a polyphenol derived from green tea leaves but has reduced off-flavors and odors derived from green tea after being heat-sterilized after being blended into a beverage and a beverage using the same.

[0002]

2. Description of the Related Art Catechins contained in tea are known to have a cholesterol elevation suppressing action (Japanese Patent No. 1620943), an α-amylase activity inhibiting action (Japanese Patent No. 3018013), and the like. To obtain such physiological effects of catechins by drinking tea, it is necessary for an adult to drink 4 to 5 cups of tea per day (Food Industry, 35 (14), 26-30, 1992). ). Therefore, there has been a demand for the development of a beverage containing a high concentration of catechin, which can more easily ingest a large amount of catechins.

In order to mix catechins at a high concentration, there is a method of using an extract of green tea leaves containing a large amount of catechins. A means for further concentrating the catechin extract from green tea leaves has been proposed. The concentrate of the tea extract is, for example, a concentrate of an extract obtained by extracting tea leaves with hot water or a water-soluble organic solvent.
219384, JP-A-4-20589, and JP-A-5-
It can be prepared by the method described in JP-A No. 260907, JP-A No. 5-306279 and the like. Examples of commercially available products include "Polyphenon" by Tokyo Food Techno Co., Ltd., "Theafran" by ITO EN Co., Ltd., "Sunphenon" by Taiyo Kagaku Co., Ltd., and the like. Concentrates of these tea extracts are roughly classified into two types, one is a concentrate of the tea extract or a concentrate spray-dried as it is, and the composition in the solid content is similar to that of the green tea leaf extract. On the other hand, concentrates of these extracts are purified by solvent extraction or using an adsorbent, etc., and it is presumed that catechins and their condensates and polymers are the main constituents.

There are several problems with increasing the catechins content of beverages using concentrates of these extracts. One is that when an unpurified concentrate of tea extract is used, when the beverage is sterilized, "offensive odor" is generated due to the concentrate of extract. Furthermore, when trying to increase the content of catechins in beverages other than green tea,
The "flavor of green tea" is brought in at the same time, and the taste of the beverage is uncomfortable. It is not preferable that the type of beverage is limited when catechins are to be ingested easily and in large amounts. To avoid these problems, there is a method of using the above-mentioned purified catechins.
However, these refined products are generally expensive, and there is a problem that a drink that can ingest a large amount of catechins cannot be obtained at low cost.

[0005]

The object of the present invention is to provide a method for producing a dry green tea polyphenol having reduced green tea-derived polyphenol-derived off-flavor after heat sterilization after blending in a beverage, but polyphenols derived from green tea leaves, and odor. It is to provide a method for producing a beverage to be used.

[0006]

Means for Solving the Problems The present inventor
After the first extraction treatment with water of less than 0 ° C, the second extraction treatment with hot water of 50 ° C or more and drying, even if blended in a beverage, an offensive odor is generated due to heat sterilization and a green tea flavor is imparted. It has been found that dry green tea polyphenols can be obtained.

That is, the present invention is characterized in that after the first extraction treatment of green tea leaves with water of less than 10 ° C., the second extraction treatment with warm water of 50 ° C. or higher and the second extraction liquid are dried. A method for producing a green tea polyphenol is provided.
The present invention also provides a beverage containing a dry green tea polyphenol.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The green tea leaves used in the method of the present invention include the genus Camellia, for example, C. sinensis, C. assamica, and
Examples include sencha, bancha, gyokuro, tencha, tea in a kettle, which are produced from tea leaves obtained from Yabukita seeds or hybrids thereof.

In the present invention, the first extraction treatment of green tea leaves is carried out by bringing cold water of less than 10 ° C. into contact with the green tea leaves. The extract liquid subjected to the first extraction treatment is discarded. When the first extraction treatment with water at a temperature of 10 ° C. or higher, the highly hydrophilic components in the catechins are significantly eluted, and the second extraction from the tea leaves after the first extraction treatment is performed.
The composition of the green tea polyphenol obtained by the extraction treatment is
It is different from the composition in which various physiological effects derived from the conventional green tea leaf composition are found. Further, although the reason is not clear, the resulting green tea polyphenol itself has a strong bitterness, which makes it difficult to mix catechins in high concentrations in various beverages. In addition, in the first extraction treatment with water of less than -5 ° C, it is difficult to prevent freezing, and energy consumption becomes large. Therefore, the water temperature of the first extraction treatment is -5 to 9 ° C,
Further, it is preferably -5 to 8 ° C, particularly preferably -5 to 5 ° C.

The amount of water used for the first extraction treatment is preferably 5 to 100 times by weight, more preferably 5 to 40 times by weight, that of green tea leaves. The first extraction treatment time depends on the method and scale, but is preferably about 1 to 120 minutes, more preferably 1 to 1
00 minutes, more preferably 1 to 80 minutes. The water used may be tap water, distilled water, ion-exchanged water, etc.,
Ion-exchanged water is preferable from the viewpoint of taste.

The first extraction processing method is an ordinary extraction means,
It can be carried out by means of stout, stirring extraction, countercurrent extraction, tea bag-like extraction and the like. In particular, a method of filling tea leaves in a column and passing cold water through the tea leaves is
Work efficiency is good when performing extraction processing. Further, an organic acid such as sodium ascorbate or an organic acid salt may be added to the water at the time of the first extraction treatment in advance. Further, a method of performing the first extraction treatment in a so-called non-oxidizing atmosphere while removing dissolved oxygen by boiling deaeration or aeration with an inert gas such as nitrogen gas may be used.

The green tea leaf which is the residue after the first extraction treatment is separated from the extract of the first extraction treatment and applied to the subsequent extraction of green tea polyphenols.

From the tea leaves subjected to the first extraction treatment to 50 ° C.
By performing the second extraction treatment with the above warm water, green tea polyphenol can be obtained. In the second extraction treatment with warm water of less than 50 ° C., the extraction efficiency of catechins is not sufficient, so it is difficult to extract green tea polyphenols useful in the preparation of beverages for expressing various physiological effects of catechins.

The main components extracted in the second extraction treatment are catechins, and it is preferable to select the second extraction treatment temperature according to the composition of the target catechins. 6
Extraction at 0 to 100 ° C is preferable from the viewpoint of extraction efficiency, and 70 to 100 ° C is more preferable.

The amount of water used for this second extraction treatment is 5 to 40 times the dry weight of the tea leaves in the first extraction treatment residue,
Particularly, 5 to 25 times by weight is preferable. The second extraction treatment time depends on the scale of the method and the apparatus, but is preferably 1 to 60 minutes for the purpose of suppressing the generation of miscellaneous tastes associated with high temperature extraction,
It is more preferably 1 to 40 minutes, still more preferably 1 to 30 minutes. As the second extraction processing method, the same method as the first extraction processing can be adopted.

Immediately after extraction, the green tea polyphenol obtained by the second extraction treatment contains 0.01 to 4% by weight, further 0.01 to 2% by weight, and particularly 0.1 to 2% by weight of non-polymerized catechins. Preferably. The non-polymer catechins in the present invention, catechin, gallocatechin, catechin gallate, non-epicatechins such as gallocatechin gallate and epicatechin, epigallocatechin, epicatechin gallate, epicatechins such as epigallocatechin gallate It is a collective term. Further, the content (gallate ratio) of gallic acid ester in the non-polymerized catechins is
45-65% by weight, further 45-60% by weight, especially 45
It is preferably about 57% by weight. Here, the gallate ratio is a value obtained by dividing the total amount of catechin gallate, gallocatechin gallate, epicatechin gallate, and epigallocatechin gallate by the total amount of the above eight catechins.

The green tea polyphenol obtained by the second extraction treatment is dried as it is or after purification treatment such as filtration. The drying means may be either spray drying or freeze drying. In particular, the freeze-drying method is preferable in that the heat load on the dried green tea polyphenol is low and the active ingredient is prevented from being denatured.

The content of gallate ester of catechin in the non-polymerized catechins in the obtained dried green tea polyphenol (gallate content) was 45 in view of taste and physiological effect.
~ 65 wt%, more preferably 45-60 wt%, especially 45-5
7% by weight is preferred.

By adding the dry green tea polyphenol obtained by the method of the present invention, catechins are contained,
It becomes possible to manufacture various beverages in which the physiological effects of catechins are expected.

The types of beverages include tea beverages other than green tea, such as semi-fermented tea beverages, fermented tea beverages, barley tea beverages, blended tea beverages, as well as coffee beverages, fruit juice beverages, sports drinks and the like. Beverages and fermented tea beverages are preferred. Oolong tea is particularly preferable in the semi-fermented tea beverage, and black tea and Puerle tea are preferable in the fermented tea beverage. These semi-fermented tea beverages or fermented tea beverages can be obtained by blending the dry green tea polyphenol obtained by the method of the present invention with the semi-fermented tea extract or fermented tea extract. That is, by blending the dry green tea polyphenol obtained by the present invention, generation of off-flavor during heat sterilization is suppressed, and further enhances the feeling of oolong tea and black tea such as oolong tea and black tea, production of various catechin-containing beverages. It will be possible.

In the beverage containing the dry green tea polyphenol of the present invention, in addition to the tea-derived component, an antioxidant, a flavoring agent,
Various esters, organic acids, organic acid salts, inorganic acids, inorganic acid salts, inorganic salts, pigments, emulsifiers, preservatives, seasonings, sweeteners, bitterness regulators, acidulants, pH regulators, quality stabilizers, etc. These additives may be blended alone or in combination.

For example, as the sweetener, sugar, glucose,
Examples include fructose, isomerized sugar, glycyrrhizin, stevia, aspartame, sucralose, fructooligosaccharide, and galactooligosaccharide. Examples of the bitterness adjusting agent include cyclic dextrin typified by cyclodextrin. As the cyclic dextrin, α-, β-, γ-cyclodextrin and branched α-, β-, γ-cyclodextrin can be used. The cyclic dextrin is contained in the beverage of the present invention in an amount of 0.05 to 0.5% by weight, preferably 0.05 to 0.4% by weight. As acidulant, in addition to fruit juice extracted from natural ingredients, citric acid,
Examples include tartaric acid, malic acid, lactic acid, fumaric acid and phosphoric acid. Inorganic acids and inorganic acid salts include phosphoric acid, disodium phosphate, sodium metaphosphate, sodium polyphosphate, and the like, and organic acids and organic acid salts include citric acid, succinic acid, itaconic acid, malic acid, sodium citrate. Etc.

Further, ascorbic acid or its salt as an antioxidant can be added to the beverage containing the dry green tea polyphenol of the present invention during or after the extraction process. The concentration of ascorbic acid or its salt in the beverage is 0.01 to 0.2% by weight from the viewpoint of antioxidant effect and taste.
Is more preferable, 0.02 to 0.15% by weight is more preferable, and 0.03 to 0.1% by weight is still more preferable.

The beverage in the present invention is preferably a packaged beverage, and the container used is a molded container containing polyethylene terephthalate as a main component (so-called PET bottle), a metal can, a metal foil, or the like, as in general beverages. Examples include a paper container and a bottle that are combined with a plastic film. The term "packaged beverage" as used herein means one that can be drunk without dilution.

In the case of a packaged beverage, for example, when it can be sterilized by heating after being filled in a container such as a metal can, it can be produced under sterilization conditions such as retort sterilization defined by the Food Sanitation Law. For those that cannot be sterilized by retort, such as PET bottles and paper containers, the sterilization conditions equivalent to the above,
For example, a method of sterilizing at high temperature for a short time with a plate heat exchanger or the like, cooling to a certain temperature and filling the container can be used. Further, aseptically, another component may be mixed and filled in the filled container.

[0026]

[Example] Measurement of catechins A beverage filtered through a filter (0.8 µm) was used as a high performance liquid chromatograph manufactured by Shimadzu Corporation (model SCL-10AV).
P) using octadecyl group-introduced packed column for liquid chromatograph L-column TM ODS (4.6 mm
Φ × 250mm: manufactured by Chemical Substance Evaluation and Research Institute)
Was mounted and the column temperature was 35 ° C. and the gradient method was used. The mobile phase solution A was a distilled aqueous solution containing 0.1 mol / L of acetic acid, the solution B was an acetonitrile solution containing 0.1 mol / L of acetic acid, the sample injection amount was 20 μL, and the UV detector wavelength was 280 nm. .

Example 1 100 g of green tea leaves was packed in an extraction column having an inner diameter of 7 cm and a height of 40 cm, and 1500 mL of 0 ° C. cold water was circulated at 500 mL / min for 10 minutes to perform the first extraction process of tea leaves. . After removing the circulating fluid, warm water at 70 ℃ 1500m
The second extraction process was performed by circulating L at 500 mL / min for 20 minutes. After the second extraction treatment, 1357 mL of the extract was recovered and immediately cooled with ice water to obtain a green tea polyphenol solution. Next, the obtained green tea polyphenol solution was freeze-dried under the following conditions to obtain dried green tea polyphenol. The sample was cooled and frozen to −40 ° C., then gradually heated from −40 ° C. to 20 ° C. over 12 hours at a vacuum degree of 0.2 Torr, and then held at 20 ° C. for 12 hours. The catechin concentration in the dry green tea polyphenol was 35.6% by weight, the gallate ratio was 55.8% by weight, and the caffeine was 8.4% by weight.

Example 2 As shown in Table 1, a dried green tea polyphenol was obtained in the same manner as in Example 1 except that the first extraction treatment temperature was 5 ° C and the second extraction treatment temperature was 85 ° C.

Example 3 As shown in Table 1, a dried green tea polyphenol was obtained in the same manner as in Example 1 except that the first extraction treatment temperature was 8 ° C and the second extraction treatment temperature was 95 ° C.

Comparative Example 1 As shown in Table 1, a dry green tea polyphenol was obtained in the same manner as in Example 1 except that the first extraction treatment was not performed and the second extraction treatment temperature was 70 ° C.

Comparative Example 2 As shown in Table 1, a dried green tea polyphenol was obtained in the same manner as in Example 1 except that the first extraction treatment temperature was 15 ° C and the second extraction treatment temperature was 85 ° C.

Comparative Example 3 As shown in Table 1, a dried green tea polyphenol was obtained in the same manner as in Example 1 except that the first extraction treatment temperature was 40 ° C and the second extraction treatment temperature was 85 ° C.

Comparative Example 4 As shown in Table 1, the procedure of Example 1 was repeated except that the first extraction treatment temperature was 70 ° C., the first extraction treatment time was 5 minutes, and the second extraction treatment temperature was 95 ° C. A dry green tea polyphenol was obtained.

Comparative Example 5 As shown in Table 1, the second extract before drying obtained in the same manner as in Example 3 was used at the inlet using a laboratory spray dryer GA-32 manufactured by Yamato Scientific Co., Ltd. The temperature was 180 ° C., the product temperature was 70 to 80 ° C., and the drying treatment was performed so as not to exceed 80 ° C.

Sensory Evaluation of Dry Green Tea Polyphenol The dry green tea polyphenol of the present invention was evaluated by three expert panelists related to flavor. As an evaluation method, 3.9 g of each dried green tea polyphenol obtained in Examples 1, 2 and 3 and Comparative Examples 1, 2, 3, 4, and 5, 2.88 g of β-cyclodextrin, Na 0.8 g of ascorbic acid, and 5 % Sodium bicarbonate aqueous solution is dissolved in deionized water to adjust the pH to 6.2.
The total amount was adjusted to 800 g. This was filled in a can and heat sterilized at 121 ° C. for 20 minutes. The evaluation items are strength of heat sterilization odor and strength of dry taste of dried green tea polyphenol aqueous solution, and the evaluation results are shown in Table 1.

In any of Examples 1 to 3, no heat sterilization odor was felt, and there was no unpleasant taste derived from dry green tea polyphenol, and the taste was refreshing.

In Comparative Example 1, a heat sterilization odor was observed. The bitterness was strong and the miscellaneous taste was noticeable. In Comparative Example 2, the heat sterilization odor was strong, and a slight odor was observed. In Comparative Example 3, the bitterness was strong, and the heat sterilization odor and the unpleasant taste were noticeable. In Comparative Example 4, the heat sterilization odor and the unpleasant taste were noticeable, and the aftertaste was accompanied by the edgy sensation derived from green tea. In Comparative Example 5, the second extraction treatment conditions similar to those in Example 3 were carried out, but the dryness was different, and therefore the unpleasant taste was recognized.

[0038]

[Table 1]

Example 4 Using the dried green tea polyphenol obtained in Example 2, a sugar-free black tea beverage was prepared by the following method. 100g tea leaves
(Darjeeling) was added to 3000 mL of warm water at 60 ° C., and extraction was performed for 3 minutes while stirring. After cooling the extract with ice, 2
Filtering was performed with two sheets of No. filter paper. 2635 g of extract was obtained, which was used as black tea extract. 210 tea extract
g, 3.8 g of dried green tea polyphenol (Example 2),
2.88 g of β-cyclodextrin and 0.8 g of ascorbic acid were added to adjust the pH to 6.2 with a 5% aqueous sodium hydrogen carbonate solution, and ion-exchanged water was further added to bring the total amount to 800 g. This was filled in a can and sterilized at 121 ° C. for 20 minutes to obtain a beverage of Example 4.

Example 5 Using the dried green tea polyphenol obtained in Example 1, an oolong tea beverage was prepared by the following method. Oolong tea leaves (color) 1
00 g was added to 3000 mL of 90 ° C. warm water, and stirred for 5
Extraction was performed for a minute. The extract was cooled with ice water, and then filtered with No. 2 filter paper (two sheets). 2628 g of extract was obtained, which was used as oolong tea extract. Oolong Tea Extract 210
g, dried green tea polyphenol 3.4 g, β-cyclodextrin 2.88 g, ascorbic acid 0.8 g, 5%
The pH was adjusted to 6.2 with a sodium bicarbonate aqueous solution, and ion-exchanged water was added to make the total amount 800 g. Fill this in a can and heat at 121 ° C for 20
Sterilization for minutes was performed to obtain the beverage of Example 5.

[Results of Sensory Evaluation of Black Tea Beverage and Oolong Tea Beverage] Beverages containing the dried green tea polyphenol of the present invention were evaluated by three expert panelists related to flavor. In all of the beverages of Examples 4 and 5, the black tea feeling and the oolong tea feeling were good, and the aroma was rich. The bitterness was moderate, and the flavor of green tea was not recognized. In addition, neither heat sterilization odor nor miscellaneous taste was felt.

[0042]

[Table 2]

INDUSTRIAL APPLICABILITY According to the present invention, a dry green tea polyphenol having abundant catechins and capable of retaining the original flavor of the beverage to be blended can be obtained. The beverage containing this dry green tea polyphenol retains the flavor of the base beverage, has no offensive odor during sterilization, and has reduced miscellaneous taste and bitterness.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Susumu Oishi             Kao Stock Association 2-1-3 Bunka, Sumida-ku, Tokyo             Company research institute F-term (reference) 4B017 LC03 LG14                 4B027 FB08 FB10 FB13 FC06 FK09                       FP72

Claims (5)

[Claims] 1. Green tea leaves are subjected to a first extraction treatment with water below 10 ° C., then a second extraction treatment with warm water above 50 ° C., and a second extraction treatment thereof.
A method for producing a dried green tea polyphenol, which comprises drying the extract. 2. 45 to 65% by weight of non-polymer catechins
The method for producing a dried green tea polyphenol according to claim 1, wherein is a gallic acid ester of catechins. 3. The production method according to claim 1, wherein the drying method is freeze-drying. 4. A beverage containing the dry green tea polyphenol obtained by the method according to claim 1. 5. A semi-fermented tea beverage or a fermented tea beverage containing the dry green tea polyphenol obtained by the method according to claim 1.