JP3629489B1 - Production method of tea extract - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a tea extract having a high extraction rate of non-polymer catechins from tea leaves and a low ratio of caffeine / non-polymer catechins, close to the natural composition of raw tea leaves, and using the tea extract Provide containerized tea beverages.
SOLUTION: Tea leaves are put into a column type extractor, and the extract is discharged while continuously supplying hot water at 45 ° C. to 95 ° C., and the extraction rate of non-polymer catechins from tea leaves is 75-100. A method for producing a tea extract that performs extraction to a percentage.
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Description

  The present invention provides a method for producing a tea extract having a high extraction rate of non-polymer catechins from tea leaves and a caffeine / non-polymer catechin ratio close to the natural composition of the raw tea leaves, and a container using the tea extract It relates to stuffed tea beverages.

  Conventionally, as a tea extract used for preparing a packaged tea beverage, a method has been adopted in which tea leaves and heated extracted water are put into an open type extraction tank generally called a kneader, and the extract is taken out after stirring. When extracting tea leaves with hot water, among the components contained in tea leaves, non-polymer catechins are less likely to be extracted than caffeine. Therefore, in this method, the ratio of caffeine / non-polymer catechins in the extract becomes higher than the natural composition of the raw tea leaves. Therefore, if the extraction condition is severed by lengthening the stirring time or raising the temperature, the extraction rate of non-polymer catechins increases, and the ratio of caffeine / non-polymer catechins in the extract approaches that of the raw tea leaves, There was a problem that the flavor was impaired.

  Moreover, as a means of obtaining a tea extract having a good flavor, tea leaves are deposited in a tea extraction tank with a wire mesh, and the extract is supplied while supplying water at 0 to 36 ° C. from which dissolved oxygen has been removed. A method of removing from the tea leaves below, cooling to -1 to 6 ° C to remove precipitates (Patent Document 1), and adding 2-3 times the amount of water to the tea leaves to moisten for several minutes, There has been reported a method (Patent Document 2) in which five times the amount of hot water at 80 to 95 ° C. is poured to elute the drinking components to make an eluent having a concentration of 5 to 10 Brix% to make a concentrated drinking tea liquid.

However, since the extraction temperature is low in the method described in Patent Document 1, the extraction rate of non-polymer catechins from tea leaves is low, and the economical efficiency is deteriorated when a packaged tea beverage is produced. In addition, since the method described in Patent Document 2 is intended to obtain a concentrated extract, the extraction is performed in a state where the amount of the extract is extremely small, so that the extraction rate of non-polymer catechins contained in tea leaves is low. When producing stuffed tea beverages, the economic efficiency deteriorates. Furthermore, the ratio of caffeine / non-polymer catechins in the extract is higher than the natural composition of the raw tea leaves.
JP 2000-50799 A JP-A-6-178651

  An object of the present invention is to provide a method for producing a tea extract with a high extraction rate of non-polymer catechins from tea leaves and a caffeine / non-polymer catechin ratio close to the natural composition of the raw tea leaves, and the tea extract. The object is to provide a containerized tea beverage used.

  Therefore, the present inventor employs a tea extraction method in which tea leaves are put into a column type extractor, and the extract is discharged while continuously supplying hot water at 45 ° C. to 95 ° C., and non-polymer catechins from tea leaves are used. It has been found that if extraction is performed so that the extraction rate of varieties is 75 to 100%, the ratio of caffeine / non-polymer catechins in the extract is lowered, and an extract close to the natural composition of the raw tea leaves is obtained. And it discovered that this tea extract liquid had favorable flavor, and the container-packed tea drink containing a non-polymer catechin in a high concentration is obtained as it is or diluted.

That is, in the present invention, tea leaves are put into a column type extractor , and the extraction liquid is completely discharged in 2 to 60 minutes while continuously supplying hot water at 45 ° C. to 95 ° C. The present invention provides a method for producing a tea extract in which the extraction rate of non-polymer catechins from tea leaves is 75 to 100%.
Extraction rate of non-polymer catechins (%) =
(Concentration of non-polymer catechins in the extract (% by weight) × extraction ratio) / (Concentration of non-polymer catechins in the extract (% by weight) × 70 when extracted at 85 ° C. up to an extraction ratio of 70) ) × 100
The present invention also provides a packaged tea beverage by diluting the obtained tea extract as it is.

  According to the present invention, a tea extract having a high extraction rate of non-polymer catechins from tea leaves and a caffeine / non-polymer catechin ratio close to the natural composition of the raw tea leaves can be produced.

  Non-polymer catechins in the present invention are non-epimeric catechins such as catechin, gallocatechin, catechin gallate, and gallocatechin gallate, and epicatechins such as epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. It is a generic name that includes

  The tea leaves used in the present invention include green teas such as sencha, gyokuro, and tencha, made from tea leaves obtained from the genus Camellia, such as C. sinensis and C. assaimica, Yabukita species, or hybrids thereof; Then, there are iron fermented teas, such as iron kannon called oolong tea, color types, golden katsura, wushuiwa tea, and so on; tea leaves of fermented teas such as darjeeling, assam, and sri lanka. Of these, green tea leaves are particularly preferred.

  In the method of the present invention, a column type extractor, for example, a closed type extraction column as shown in FIG. 1 is used. The tea leaves 4 are charged into the extraction column 3. By using a closed column, flavor components can be sufficiently recovered.

  In the present invention, the method of passing extraction water through one column from one column to the other in one pass has a smaller heat history received by the extract than the method of circulating a predetermined amount of water in a tank. It is preferable in that the quality deterioration due to is small. The direction of liquid flow may be an upward flow or a downward flow.

The temperature of the water used for extraction is 45 to 95 ° C, preferably 50 to 85 ° C, and particularly preferably 60 to 80 ° C. When the temperature is lower than 45 ° C., a large amount of water is required to increase the extraction rate of the non-polymer catechins, and the extraction time becomes long, resulting in poor workability and economy.
Further, the value obtained by dividing the water supply flow rate by the cross-sectional area of the column, that is, the linear velocity of water in the column is 1.0 to 20.0 cm / min, preferably 2.0 to 15.0 cm / min, particularly 3. 0-10.0 cm / min is preferable. If the linear velocity is too high, the tea leaves will become compact and block. On the other hand, if the linear velocity is too slow, the time of the extraction process becomes long, and the working efficiency is lowered.
The value obtained by dividing the height of the swollen tea leaf layer during extraction by the above linear velocity, that is, the average residence time of water in the tea leaf layer is 0.5 to 15.0 min, preferably 0.7 to 10 0.0 min, particularly 0.9 to 8.0 min is preferable. If the average residence time is too short, the extraction of the non-polymer catechins is insufficient, and if it is too long, the extraction process takes a long time and the working efficiency decreases.
The preparation height of tea leaves before the start of extraction is 30 to 500 mm, preferably 40 to 300 mm, and particularly preferably 50 to 200 mm. If the preparation height is too high, the pressure loss of the tea leaf layer increases and the flow velocity decreases. On the other hand, if the preparation height is too low, the batch size of one extraction becomes small, and it is necessary to perform many extractions, so that the work efficiency decreases.

  When the extraction ratio, that is, (weight of the extract extracted from the column) / (prepared weight of tea leaves) is low, the concentration of non-polymer catechins in the tea extract increases, but the extraction rate of non-polymer catechins from tea leaves Does not increase. On the other hand, if it is too high, the extraction rate of non-polymer catechins increases, but the concentration of non-polymer catechins in the resulting tea extract becomes low. The extraction magnification is preferably 10 to 100, preferably 15 to 80, and particularly preferably 20 to 60 from the viewpoint of improving the economic efficiency by increasing the extraction rate from tea leaves and producing a beverage containing a high concentration of catechin.

In order to calculate the extraction rate (%) of non-polymer catechins in the present invention, it is necessary to examine the total amount of non-polymer catechins contained in tea leaves. When tea leaves are charged into a column and ion-exchanged water is passed through at 85 ° C. (one-pass extraction) , the concentration of non-polymer catechins and caffeine at the column outlet is initially high but gradually decreases. Sometimes it became zero, and it was confirmed that all non-polymer catechins and caffeine were eluted from the tea leaves. Therefore, the amount of non-polymer catechins and caffeine contained in the raw tea leaves in the present invention is the amount of non-polymer catechins and caffeine in the extract when the column method is used to extract one pass up to an extraction ratio of 70 at 85 ° C. Say quantity. At this time, the concentration of non-polymer catechins in the extract obtained in the tank is defined as A (% by weight). In this case, the extraction rate (%) of non-polymer catechins under each condition is expressed by the following formula:

(Equation 1)
(Non-polymer catechin concentration (% by weight) × extraction ratio / (A × 70)) × 100 in the extract under each condition

Is required. The denominator of the formula is the total amount of non-polymer catechins contained per unit amount of tea leaves. In this invention, it extracts so that the extraction rate of this non-polymer catechin may be 75-100%. If this extraction rate is less than 75%, the ratio of caffeine / non-polymer catechins of the extract will be higher than that of the natural composition of the raw tea leaves. Here, since the total amount of non-polymer catechins contained in tea leaves varies depending on the type, origin, and year of the raw tea leaves, it may be measured by a preliminary extraction test.

As described above, the concentration ratio of caffeine / non-polymer catechins in the extract obtained in the tank when passing through the column method at 85 ° C. up to an extraction ratio of 70 (one-pass extraction) is the raw material. It was judged to be equal to the ratio of caffeine / non-polymer catechins (weight ratio) in tea leaves. In the present invention, the extraction is performed so that the ratio of caffeine / non-polymer catechins in the extract is 100 to 110% of the ratio of caffeine / non-polymer catechins in the raw tea leaves. In the conventional extraction method, since non-polymer catechins are less likely to be extracted than caffeine, it becomes higher than 110% and deviates from the natural composition of the raw tea leaves. The ratio of caffeine / non-polymer catechins (weight ratio) in the tea extract thus obtained is 100 to 110%, and further 100 to 108% of the ratio of caffeine / non-polymer catechins contained in the raw tea leaves. In particular, it is preferably 100 to 105%.

  The extraction treatment time in the method of the present invention is determined by the extraction rate of the non-polymer catechins, but in the case of 1-pass extraction, it is preferably 2 to 60 minutes, more preferably 3 to 48 minutes, and particularly preferably 4 to 28 minutes.

  The tea extract thus obtained has a ratio of caffeine / non-polymer catechins close to the natural composition of the raw tea leaves, and has little miscellaneous taste and good flavor. be able to. At this time, the concentration of non-polymer catechins is 0.05 to 0.5% by weight, preferably 0.06 to 0.5% by weight, more preferably 0.07 to 0.5% by weight, and still more preferably 0. 0.08 to 0.4 wt%, particularly preferably 0.09 to 0.4 wt%, most preferably 0.10 to 0.3 wt%, most preferably 0.12 to 0.3 wt% It is preferable to obtain the effect of promoting the accumulation of fat burning of non-polymer catechins, the effect of promoting the burning of dietary fat, the effect of promoting the expression of liver β-oxidized gene (JP 2002-326932 A), and the like.

  Further, the ratio of the generic gallate body consisting of catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate in the non-category catechins in the packaged tea beverage of the present invention is 35 to 100% by weight, The amount of 35 to 98% by weight, particularly 35 to 95% by weight, is preferable in view of the effectiveness of physiological effects of non-polymer catechins.

  The packaged tea beverage of the present invention is preferably mixed with a bitter and astringent taste suppressant because it is easy to drink. As the bitter and astringent taste inhibitor to be used, cyclodextrin is preferable. As the cyclodextrin, α-, β-, γ-cyclodextrin and branched α-, β-, γ-cyclodextrin can be used. The cyclodextrin is contained in the beverage in an amount of 0.005 to 0.5% by weight, preferably 0.01 to 0.3% by weight. The packaged tea beverage of the present invention includes an antioxidant, a fragrance, various esters, an organic acid, an organic acid salt, an inorganic acid, an inorganic acid salt, an inorganic salt, a pigment, an emulsifier, a preservative, a seasoning, and a sweetener. Additives such as acidulants, gums, oils, vitamins, amino acids, fruit juice extracts, vegetable extracts, nectar extracts, pH adjusters and quality stabilizers may be used alone or in combination.

  The pH of the packaged tea beverage of the present invention is preferably 3 to 7, preferably 4 to 7, particularly 5 to 7 at 25 ° C. from the viewpoint of flavor and catechin stability.

The ingested tea beverage of the present invention has an intake of adult fat for promoting accumulation fat burning promotion, dietary fat burning promotion and liver β-oxidation gene expression promotion, as a non-polymer catechin, 300 mg or more, Preferably it is 450 mg or more, more preferably 500 mg or more. Specifically, anti-obesity effects and visceral fat reduction effects have been confirmed by ingesting 483 mg, 555 mg, 900 mg, and the like per beverage (JP 2002-326932 A).
Accordingly, in the packaged tea beverage of the present invention, the daily intake amount for adults is 300 mg or more, preferably 450 mg or more, more preferably 500 mg or more as non-polymer catechins, and the necessary daily intake is ensured. Is preferred.

  The container used for the container-packed tea beverage of the present invention is a molded container mainly composed of polyethylene terephthalate (so-called PET bottle), a metal can, a paper container combined with a metal foil or a plastic film, like a general beverage, It can be provided in a conventional form such as a bottle. The term “packaged beverage” as used herein means a beverage that can be drunk without dilution.

  The container-packed tea beverage of the present invention is manufactured under the sterilization conditions stipulated in the Food Sanitation Law if it can be sterilized by heating after filling the container like a metal can. For those that cannot be sterilized by retort, the same sterilization conditions as described above, for example, a high-temperature and short-time sterilization using a plate heat exchanger or the like, followed by cooling to a certain temperature and filling into a container are adopted. Moreover, you may mix | blend another component with the filled container under aseptic conditions. Furthermore, after sterilization by heating under acidic conditions, the pH may be returned to neutrality under aseptic conditions, or after sterilization by heating under neutral conditions, the pH may be returned to acidic conditions under aseptic conditions.

Octadecyl group-introduced liquid chromatograph using a high-performance liquid chromatograph (model SCL-10Avp) manufactured by Shimadzu Corporation, which was filtered with a catechin measurement filter (0.8 μm) and then diluted with distilled water. A packed column L-column TM ODS (4.6 mmφ × 250 mm: manufactured by Chemicals Evaluation and Research Institute) was attached, and a gradient method was performed at a column temperature of 35 ° C. The mobile phase A solution was a distilled aqueous solution containing 0.1 mol / L of acetic acid, and the B solution was an acetonitrile solution containing 0.1 mol / L of acetic acid, and the solution was sent at a flow rate of 1.0 mL / min. The gradient conditions are as follows.
Time A liquid B liquid
0 minutes 97% 3%
5 minutes 97% 3%
37 minutes 80% 20%
43 minutes 80% 20%
43.5 minutes 0% 100%
48.5 minutes 0% 100%
The sample injection volume was 10 μL, and the UV detector wavelength was 280 nm.

Measurement of caffeine The amount of caffeine was determined simultaneously with the measurement of the catechins. The retention time for caffeine was 27.2 minutes.

Extraction apparatus The tea extract was manufactured using the extraction apparatus shown in FIG. Extraction water was heated by a pump 1 through a heat exchanger for heating ion exchange water, and passed through the extraction column 3 from below to above or from above to below. The tea leaves 4 were charged between the tea leaf holding plate (lower) 6 and the tea leaf holding plate (upper) in the extraction column. The extract was recovered in the extract recovery tank 8 via the heat exchanger 7 for cooling the extract. The extraction device may have a mechanism capable of holding tea leaves in a columnar tea leaf filling chamber.

Example 1
100 g of green tea leaves from Miyazaki were packed in a closed extraction column (inner diameter 70 mm, height 137 mm), and ion-exchanged water heated to 65 ° C. was passed from the bottom to the top at a rate of 0.50 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 13.0 cm / min, and the average residence time was 1.1 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 60 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

Example 2
100 g of green tea leaves from Miyazaki were packed in a closed extraction column (inner diameter 70 mm, height 137 mm), and ion-exchanged water heated to 85 ° C. was passed from the bottom to the top at a rate of 0.25 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 6.5 cm / min, and the average residence time was 2.2 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 40 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

Example 3
100 g of green tea leaves from Miyazaki were packed in a closed extraction column (inner diameter 70 mm, height 250 mm), and ion-exchanged water heated to 65 ° C. was passed from the top of the column to the bottom at a rate of 0.50 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 13.0 cm / min, and the average residence time was 3.1 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 30 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

Comparative Example 1
In a kneader, 4320 g of ion-exchanged water heated to 65 ° C. and 144 g of green tea leaves from Miyazaki were placed and extracted with stirring for 5 minutes. Thereafter, the tea leaves were removed from the extract with a tea leaf separator and cooled to 25 ° C. or lower with a heat exchanger. The obtained extract was uniformly mixed for analysis.

Comparative Example 2
100 g of green tea leaves from Miyazaki were packed in a closed extraction column (inner diameter 70 mm, height 137 mm), and ion-exchanged water heated to 65 ° C. was passed from the bottom to the top at a rate of 0.25 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 6.5 cm / min, and the average residence time was 2.2 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 10 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

Comparative Example 3
100 g of green tea leaves from Miyazaki were packed into a closed extraction column (inner diameter 70 mm, height 137 mm), and ion-exchanged water heated to 40 ° C. was passed from the bottom of the column upward at a rate of 0.25 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 6.5 cm / min, and the average residence time was 2.2 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 117 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

Comparative Example 4
100 g of green tea leaves from Miyazaki were packed into a closed extraction column (inner diameter 70 mm, height 137 mm), and ion-exchanged water heated to 95 ° C. was passed from the bottom of the column upward at a rate of 0.25 L / min. At this time, the initial tea leaf preparation height was 75 mm, the linear velocity was 6.5 cm / min, and the average residence time was 2.2 min. The extract was immediately cooled to 25 ° C. or lower with a heat exchanger. When the weight of the extracted liquid became 5 times the weight of the charged tea leaves, the liquid passing was terminated, and the liquid in the tank was uniformly mixed for analysis.

  Table 1 shows the results of extraction conditions, Brix of the obtained extract, non-polymer catechin concentration, caffeine concentration, caffeine / non-polymer catechin ratio, and extraction rate.

  The tea extracts obtained in Examples 1 to 3 had a caffeine / non-polymer catechin ratio of 110% or less of the caffeine / non-polymer catechin ratio of the raw tea leaves, which was close to the natural composition. All of the tea extracts obtained in Comparative Examples 1 to 4 had a caffeine / non-polymer catechin ratio exceeding 110% of that of the raw tea leaves and deviated from the natural composition.

Example 4
The tea extract obtained in Examples 1 to 3 is diluted with ion-exchanged water as necessary, and adjusted so that the non-polymer catechin concentration is 0.05 to 0.338% by weight. A beverage was produced. All of the obtained beverages had a caffeine / non-polymer catechin ratio close to that of the raw tea leaves and a good flavor.

It is a figure which shows the outline of the extraction method using the column type extractor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump 2 Ion-exchange water heating exchanger 3 Column type extractor 4 Tea leaf 5 Tea leaf holding plate (top)
6 Tea leaf holding plate (bottom)
7 Heat exchanger for cooling the extract 8 Extract recovery tank

Claims (5)

The tea leaves are put into a column type extractor, and the discharge of the extract is completed in 2 to 60 minutes while continuously supplying hot water at 45 ° C. to 95 ° C., and the non-polymer from the tea leaves represented by the following formula A method for producing a tea extract, wherein the extraction rate of catechins is 75 to 100%.
Extraction rate of non-polymer catechins (%) =
(Concentration of non-polymer catechins in the extract (% by weight) × extraction ratio) / (Concentration of non-polymer catechins in the extract (% by weight) × 70 when extracted at 85 ° C. up to an extraction ratio of 70) ) × 100   The method for producing a tea extract according to claim 1, wherein the ratio of caffeine / non-polymer catechins in the obtained tea extract is 100 to 110% of the ratio of caffeine / non-polymer catechins contained in the raw tea leaves.   The method for producing a tea extract according to claim 1 or 2, wherein the tea leaves are green tea leaves.   A packaged tea beverage obtained by directly or diluting the tea extract obtained by the method according to any one of claims 1 to 3.   The packaged tea beverage according to claim 4, wherein the concentration of non-polymer catechins is 0.05 to 0.5% by weight.

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