JP2009065871A - Tea extract and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tea extract or tea drink which prevents the formation of precipitates (dregs) on preservation for a long period and has proper flavor without deteriorating the effectiveness of polymerized catechin, and to provide a method for producing the same. <P>SOLUTION: There is provided a method for producing the tea extract, including (1) a process for contacting tea leaves with a solvent to obtain a tea extract; (2) a process for obtaining a polymerized catechin concentrate in an enhanced polymerized catechin / non-polymerized catechin ratio in the tea extract; and (3) a process for removing particles, having specific particle diameters from the polymerized catechin concentrate, and the tea extract obtained by the method for producing the tea extract. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tea extract containing a high concentration of polymerized catechins, and more particularly, an extract of a fermented tea or semi-fermented tea containing a high concentration of polymerized catechins, which has long-term storage stability. The present invention also relates to a tea extract excellent in flavor and a method for producing the same.

  In recent years, many tea beverages filled in containers have been put on the market. Such a tea beverage is generally produced by extracting tea particles from water extracted from tea leaves (including warm water), if necessary, by removing the tea particles by centrifugation or the like, and then filling the container. In recent years, addition of an antioxidant and a pH adjuster has been performed before filling the container.

  The conventional container-filled tea beverages manufactured in this way are generally known to form turbidity such as suspended matter and sediment (ori) by long-term storage. It is thought that this is because polymer components such as polyphenols are modified by association or the like. Such turbidity is a cause of visual deterioration of products, particularly in the case of products filled in PET bottle containers. Manufacturing methods have been proposed.

  For example, Patent Document 1 eliminates crystallization of precipitates, which is characterized by adding an appropriate amount of chitosan to green tea extract, adsorbing polymer component polyphenols, and removing them by centrifugation. A method for producing a Kiyosumi green tea beverage is disclosed.

  Patent Document 2 discloses a green tea extraction step, a tea shell removal step of removing the tea husk from the green tea extract by passing the green tea extract while oscillating an 80-200 mesh filter after the extraction step, and the tea husk removal. A method for producing a clarified green tea beverage comprising cooling a green tea extract after the process and performing a turbid component removal step of performing centrifugation at a speed of 5000 to 10000 rpm is disclosed, and the turbid component is obtained without impairing the original flavor of the green tea. It is described that a clear green tea beverage from which the odor is removed is obtained.

  In Patent Document 3, an extract obtained by extracting hot water from oolong tea leaves is concentrated to Brix 10 to 40, and solids are removed from the concentrate by centrifugation under conditions of 3000 to 16000 G, when diluted to Brix 0.2. A method for producing an oolong tea extract having a turbidity of 0.017 or less is disclosed. It is described that a tea beverage blended with oolong tea extract obtained by this method has high transparency, good taste and aroma, and does not cause turbidity or orientation after long-term storage.

  In Patent Document 4, as a method for producing a guava tea beverage that suppresses the occurrence of precipitation and enables long-term storage without reducing the effectiveness of guava tea, the guava tea extract has a retained particle size of 5 μm or less. A method of removing ellagic acid by microfiltration with a filter is disclosed.

Patent Document 5 pays attention to the physiological effect of tea-derived polymerized catechins, reports on its lipase inhibitory action, and discloses beverages with enhanced polymerized catechins.
JP-A-6-31847 Japanese Patent Laid-Open No. 10-290666 Japanese Patent Laid-Open No. 2005-40031 JP 2003-208 JP International Publication WO2005 / 077384

  As described above, conventionally, as a method for preventing turbidity during long-term storage of tea beverages, a method of mainly removing a polymer component has been known. However, in tea extracts or tea beverages containing a high concentration of polymerized catechin, which is a polymer polyphenol, turbidity is formed while maintaining the physiological effect of polymerized catechin (that is, containing polymerized catechin at a high concentration). Since it is necessary to prevent this, a conventionally known method for removing a polymer component cannot be substantially applied.

  An object of the present invention is to provide a tea extract or tea beverage having a good flavor that suppresses the occurrence of precipitation (ori) during long-term storage without reducing the effectiveness of polymerized catechins, and a method for producing the same. It is to provide.

  As a result of intensive studies to solve the above problems, the present inventors have processed a oolong tea leaf extract to obtain a tea extract containing a higher concentration of polymerized catechins than non-polymerized catechins. The present inventors have found that a tea extract containing a high concentration of polymerized catechin that does not generate a precipitate even when stored for a long period of time can be obtained by removing a component having an average particle size of 0.8 μm or more. Surprisingly, it was found that even when components having an average particle size of 0.8 μm or more were removed, the good flavor of the tea extract and the effectiveness of the polymerized catechin were maintained as they were, and the present invention was completed. It came to do.

That is, the present invention is as follows.
1. A tea extract containing non-polymerized catechins and polymerized catechins, wherein the tea extract contains 2% or less of particles having a particle diameter of 0.8 μm or more.
2. 2. The tea extract according to 1 above, which contains a higher concentration of polymerized catechin than non-polymerized catechin.
3. The tea extract as described in 2 above, which contains polymerized catechin at a concentration 4 times or more that of non-polymerized catechin.
4). The tea extract according to any one of 1 to 3 above, wherein the polymerized catechin is derived from semi-fermented tea or fermented tea.
5). Next steps (1) to (3),
(1) A step of bringing a tea leaf into contact with a solvent to obtain a tea extract;
(2) A step of obtaining a polymerized catechin concentrate having an increased ratio of polymerized catechin to non-polymerized catechin from the tea extract; and (3) a step of performing a centrifugal treatment of the polymerized catechin concentrate to obtain a supernatant;
The tea extract in any one of said 1-4 obtained by the process including this.
6). Further next step (4),
(4) The tea extract as described in 5 above, which comprises a step of passing a 300-700 mesh filter through the supernatant.
7). The tea extract according to 5 or 6 above, wherein the Brix of the polymerized catechin concentrate at the time of centrifugation in the step (3) is 1 or more and less than 10.
8). Tea drink containing the tea extract of any one of said 1-7.
9. 9. The tea beverage according to 8 above, wherein the content of the polymerized catechin is 0.010% by weight to 0.100% by weight.

BEST MODE FOR CARRYING OUT THE INVENTION

  The present invention relates to a tea extract in which particles having an average particle size of 0.8 μm or more are 2% or less, preferably 1.5% or less, more preferably 1.0% or less, among all the particles in the tea extract. In this way, a tea extract enriched with polymerized catechins, which does not form a precipitate even when stored for a long period of time, has a good flavor, and maintains the effectiveness of the polymerized catechins. You can get things.

A tea extract enriched with polymerized catechins is one in which the ratio of polymerized catechins in the tea extract is increased with respect to non-polymerized catechins. Specifically, polymerized catechins are higher than non-polymerized catechins. Tea extract containing at a concentration.
(Polymerized catechin)
The polymerized catechin in the present specification is a component analyzed by HPLC under the following conditions, and is a component that has the same elution time (reference elution time: 24 min.) As theaflavin (manufactured by Kurita Research Center).
HPLC conditions:
Column: TSK-gel ODS-80TsQA (4.6mmφx150mm, Tosoh Corporation)
-Mobile phase: A: Water: Acetonitrile: Trifluoroacetic acid = 900: 100: 0.5
B: Water: Acetonitrile: Trifluoroacetic acid = 200: 800: 0.5
・ Flow rate: 1.0ml / min
・ Column temperature: 40 ℃
・ Gradient condition: B solution 0% until 5 minutes after the start of analysis
From 5 minutes to 11 minutes, B liquid 8%,
From 11 minutes to 21 minutes, B solution 10%,
From 21 minutes to 22 minutes, solution B is 100%,
100% hold from 22 to 30 minutes,
0% from 30 to 31 minutes
・ Detection: A280nm (data collection time is 30 minutes), quantified by peak area.
・ Injection volume: 10μL
Reference material: Oolong homobisflavan B (abbreviation: OHBF-B)
The amount of polymerized catechin is determined by creating a calibration curve using OHBF-B as a standard substance. The standard substance OHBF-B was synthesized according to, for example, the method described in Chem. Pharm. Bull 37 (12), 3255-3563 (1989) or the method of Example 3 of JP-A-2005-336117. A product (preferably purified to a purity of 98% or more), a product isolated from tea leaves, or the like can be used.

  As this polymerized catechin, non-polymerized catechins ((+)-catechin, (−)-epicatechin, (+)-gallocatechin, (−)-epigallocatechin, (−)-catechin gallate, (−) — Epicatechin gallate, (-)-gallocatechin gallate, (-)-epigallocatechin gallate) can be exemplified by those having a structure in which a plurality of tea-derived enzymes, enzymes, light, etc. are linked, specifically thealvidin etc. A polymerized polyphenol called by the common name of the following, epigallocatechin gallate dimer of formula (1),

  Epigallocatechin gallate trimer of formula (2),

  A dimer of epigallocatechin of formula (3),

(In the formula, R 1 and R 2 are each independently H or a galloyl group.)
Trimer of epigallocatechin of formula (4)

(In the formula, R ₃ , R ₄ and R ₅ are each independently H or a galloyl group.)
Oolong theanine-3'-O-gallate of formula (5)

And other polymerized polyphenols.
Non-polymerized catechins include catechins ((+)-catechin, (−)-epicatechin, (+)-gallocatechin, (−)-epigallocatechin, (−)-catechin gallate, (−)-epi. Catechin gallate, (−)-gallocatechin gallate, (−)-epigallocatechin gallate) is an unpolymerized monomer.
(Tea extract)
The tea extract of the present invention is used as a tea extract in which polymerized catechins in which the ratio of polymerized catechins in the tea extract is increased with respect to non-polymerized catechins are concentrated. As the tea extract, a conventionally known solvent extract of tea leaves can be used, and among the tea leaves, among non-fermented green tea, semi-fermented tea oolong tea, fermented tea 1 One type or two or more types can be used. Among them, it is preferable to use semi-fermented tea, fermented tea containing a large amount of polymerized catechin, or tea leaves mixed with these.

The extraction solvent can be extracted with water or hot water, methanol, ethanol, isopropanol, ethyl acetate, or the like, or a mixture of one or more of these solvents. Further, the extraction method and extraction conditions are not limited at all. For example, the extraction is performed at a solvent temperature of 50 to 100 ° C., preferably 80 to 100 ° C., by a conventional method such as stirring extraction. At the time of extraction, an antioxidant such as sodium ascorbate or a pH adjusting agent such as sodium bicarbonate may be added to the extraction solvent.
(Concentration of polymerized catechin)
From this tea leaf solvent extract (Brix 1-8), by selectively concentrating polymerized catechins, a tea extract containing polymer catechins at a higher concentration than non-polymerized catechins, preferably polymerized catechins to non-polymerized catechins. A tea extract with a ratio of 4 or more is obtained. Any known method may be used for concentration of the polymerized catechin. For example, the method described in WO2005 / 077384, that is, adsorbing the solvent extract of tea leaves as described above at a liquid temperature of 50 ° C. or higher. The method of making it contact with an agent and concentrating polymerized catechin as a non-adsorption fraction can be illustrated. The concentrated solution of polymerized catechins obtained by this method is one obtained by removing bitterness and astringency while having the original flavor of tea leaves (Brix 1 to 8).
(Removal of specific particles)
The polymer catechin concentrate (tea extract) thus obtained depends on the type of tea leaves used and the extraction method, but the above method contains particles having a particle size of about 0.3 to 1.6 μm. The average particle size is about 0.60 ± 0.03 μm. The present invention has found that, in a tea extract containing a high concentration of polymerized catechin, particles of 0.8 μm or more are the main components that form a precipitate, and the main component that forms this precipitate is not a polymerized catechin. Is based on that. That is, the tea extract of the present invention removes only particles of 0.8 μm or more, which are precipitation components, from a tea extract containing a high concentration of polymerized catechins without changing the concentration of polymerized catechins having physiological effects. Tea extract. And the average particle diameter of the particle | grains which exist in this tea extract is about 0.43 +/- 0.01micrometer.

  As a method for removing the particles having a size of 0.8 μm or more, a conventionally known centrifugal separation method can be exemplified. Examples of the centrifugal separation method include a method of removing solids by centrifugation at 10,000 to 20000 × g. When performing centrifugation, it is preferable from a viewpoint of flavor and precipitation prevention that the liquid temperature of a tea concentrate is 4-40 degreeC.

  In addition, the concentrated liquid of polymerized catechin at the time of the above centrifugation is less than Brix 10, preferably Brix 5 or less, more preferably Brix 3 or less. As described above, the tea extract of the present invention is characterized in that only the precipitation component is removed without changing the concentration of the polymerized catechin having physiological activity. When the Brix is 10 or more, particles that cause precipitation can be efficiently removed by centrifugation, and precipitation formation during storage can be remarkably suppressed, but polymerized catechins are also separated together with precipitation-forming particles. The physiological activity of the obtained tea extract will fall. On the other hand, the lower limit is Brix 1 or more, preferably 1.5 or more. If it is less than Brix 1, the effect of centrifugation cannot be sufficiently obtained, and particles having a particle size of 0.8 μm or more may not be completely removed, which is not preferable from the viewpoint of preventing precipitation.

  The polymerized catechin concentration of the polymerized catechin concentrated solution (tea extract containing polymerized catechin at a higher concentration than non-polymerized catechin) at the time of centrifugation may be Brix in the above preferred range, and polymerized catechin concentrated solution. May be used after further concentration by vacuum concentration or the like, or may be diluted.

  The supernatant obtained by centrifugation or the like can be further filtered. For example, when the supernatant is passed through a filter of 300 to 700 mesh, preferably 500 mesh, a tea extract that can withstand long-term storage can be obtained.

(Tea drinks and other drinks)
The tea extract of the present invention is diluted to an appropriate concentration in water or added to a tea extract as a tea beverage, or added to an aqueous solution containing sugar and acid as a soft drink (acid solution). Can be used.

  When used as the above tea beverage, the content of the polymerized catechin may be appropriately set in consideration of the effect of the polymerized catechin, the flavor of the tea beverage, etc., but is usually 0.010% by weight to 0.100% by weight. Preferably, it is about 0.015 wt% to 0.500 wt%. If the polymerized catechin is 0.010% by weight or more, the physiological activity of the polymerized catechin such as lipase inhibitory activity can be imparted to the beverage. Moreover, when it exceeds 0.100 weight%, the bitterness and astringency derived from weight catechin may generate | occur | produce and it is not preferable in flavor.

  As described above, the tea extract of the present invention can prevent the formation of precipitates not only in so-called neutral beverages such as tea beverages but also in acidic solutions where precipitation is likely to occur even when stored for a long period of time. it can. Moreover, not only the prevention of precipitation but also the good flavor of the beverage is maintained. Therefore, the optimum pH of the beverage of the present invention is pH 2-8, preferably pH 2.5-7.0.

  By using the tea extract of the present invention, it is possible to produce a beverage that suppresses the occurrence of precipitation. There are two types of precipitation (ori): ori (primary ori) that precipitates immediately after the production of the beverage and ori (secondary ori) that occurs over time during storage of the beverage. Any orientation is suppressed.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.
[Example 1: Production of tea extract]
Using 7800 kg of baking soda solution in which 0.15% by weight of baking soda was added to warm water (95 ° C.), 600 kg of oolong tea leaves were subjected to extraction treatment to obtain about 7000 kg of oolong tea extract. While maintaining the liquid temperature of this extract at 60-65 ° C., it was passed through 400 kg of granular activated carbon (GW-H32 / 60 manufactured by Kuraray Co., Ltd.) to remove non-polymerized catechins and caffeine. This passing liquid (liquid after activated carbon treatment) was concentrated under reduced pressure to obtain about 900 kg of Brix11 polymerized catechin-containing oolong tea concentrate (hereinafter referred to as concentrated extract).

Next, this concentrated extract was diluted 5 times with water, centrifuged (6000 rpm, 5 minutes) (about 14000 × g), and the supernatant was passed through a 500 mesh filter. The tea extract thus obtained (hereinafter referred to as “centrifugal extract”) was subjected to the following analysis.
(1) Particle size The particle size of the particles contained in the tea extract was analyzed using a particulate counter (manufactured by Particle Measuring Systems). As the analysis target, a centrifugal extract and a tea extract that was not subjected to centrifugal separation and filter treatment (hereinafter, untreated extract) were used.
(2) Polymerized catechin concentration The polymerized catechin concentration in the centrifuged extract was analyzed by HPLC. In addition, the same analysis was performed on an untreated extract diluted 5 times with water. The analysis conditions of HPLC are as follows.

(HPLC conditions)
Column: TSKgel ODS-80TsQA (150 mm x 4.6 mmφ Tosoh Corporation)
Mobile phase: A: water: acetonitrile: trifluoroacetic acid = 900: 100: 0.5
B: Water: Acetonitrile: Trifluoroacetic acid = 200: 800: 0.5
Flow rate: 1.0 ml / min
Column temperature; 40 ° C
Gradient condition: B solution 0% until 5 minutes after the start of analysis
From 5 minutes to 11 minutes, B liquid 8%,
From 11 minutes to 21 minutes, B solution 10%,
From 21 minutes to 22 minutes, solution B is 100%,
100% hold from 22 to 30 minutes,
0% from 30 to 31 minutes
Detection wavelength: A280nm (data collection time is 30 minutes), quantified by peak area.

Injection volume: 10μL
Reference material: Oolong homobisflavan B OHBF-B
In FIG. 1, the analysis result of the particle diameter of the particle | grains in the centrifugation process extract which removed the particle | grains by centrifugation, and the extract without a centrifugation process is shown. Centrifugal extracts had a particle size of 0.8 μm or more and 1000 pieces / 10 ml or less (0.8% or less of the whole), and the average particle size was 0.43 ± 0.01 μm. On the other hand, there were about 46000 pieces / 10 ml (about 26% of the whole) of untreated extracts having a particle size of 0.8 μm or more, and the average particle size was 0.60 ± 0.03 μm.

  FIG. 2 shows an HPLC chromatogram. FIG. 2 is a chart of the untreated extract. From the results of HPLC analysis, the concentration of polymerized catechin was 537.5 ± 69.3 ppm for the untreated extract as a weight standard, whereas it was 548.6 ± 27.4 ppm for the centrifugally treated extract. Was found to not change.

[Example 2: Storage test (1)]
Phosphoric acid was added to the centrifugally treated extract of Example 1 to prepare a phosphoric acid aqueous solution (acidic, pH 3.5) having a concentration of the centrifugally treated extract of 180 ppm based on weight. Further, a neutral (pH 6.3) aqueous solution in which the concentration of the centrifugally treated extract of Example 1 was blended with 230 ppm based on weight was prepared. As a control, a mixture containing the same amount of untreated extract instead of the centrifugally treated extract was also prepared. In each of the aqueous solutions, no primary orientation was confirmed.

Each aqueous solution was stored at 4 ° C. for 1 week, and the occurrence of secondary orientation was visually observed. In both the acidic solution and the neutral solution, secondary extract was confirmed in the untreated extract (control), and particularly in the acidic solution. On the other hand, the aqueous solution prepared using the centrifugally treated extract did not generate secondary sediment compared to the control. Further, when each aqueous solution was stored at 4 ° C. for 1 week, even when the aqueous solution prepared using the centrifugally treated extract was slightly secondary, it was clearly less than the control.
[Example 3: Storage test (2)]
A carbonated beverage containing 260 ppm each of the untreated extract (Prototype 1) or the centrifugally treated extract (Prototype 2) of Production Example 1 with the composition shown in Table 1 below was prepared. In the table, phosphoric acid was added to a final pH of 3.5, and carbon dioxide gas was added to a gas pressure of 3.5 kgf / cm ² . These were stored at 4 ° C. for 1 week, and the occurrence of secondary orientation was visually observed. As a result, secondary orientation occurred in prototype (1), but secondary orientation did not occur in prototype (2). Further, when each aqueous solution was stored at 4 ° C. for 1 week, even when the aqueous solution prepared using the centrifugal extract was slightly secondary, it was clearly less than the prototype (1).

〔発明の効果〕

〔The invention's effect〕

    According to the present invention, without reducing the effectiveness of polymerized catechins, the occurrence of precipitation (ori) during long-term storage is suppressed, and a tea extract or tea beverage having a good flavor and a method for producing the same are provided. can get.

The analysis result of the particle diameter of the particle | grains in the centrifugation processing extract which removed the particle | grains by centrifugation in Example 1, and the non-centrifugal extraction is shown. The HPLC chromatogram of the untreated extract in Example 1 is shown.

Claims (9)

  A tea extract containing non-polymerized catechins and polymerized catechins, wherein in the tea extract, particles having a particle size of 0.8 μm or more are 2% or less.   The tea extract according to claim 1, which contains polymerized catechin at a higher concentration than non-polymerized catechin.   The tea extract according to claim 2, comprising polymerized catechins at a concentration 4 times or more that of non-polymerized catechins.   The tea extract according to any one of claims 1 to 3, wherein the polymerized catechin is derived from semi-fermented tea or fermented tea. Next steps (1) to (3),
(1) A step of bringing a tea leaf into contact with a solvent to obtain a tea extract;
(2) A step of obtaining a polymerized catechin concentrate having an increased ratio of polymerized catechin to non-polymerized catechin from the tea extract; and (3) a step of centrifuging the polymerized catechin concentrate to obtain a supernatant. ;
The tea extract of any one of Claims 1-4 obtained by the process including this. Further next step (4),
(4) The tea extract according to claim 5, comprising a step of passing a 300-700 mesh filter through the supernatant.   The tea extract according to claim 5 or 6, wherein Brix of the polymerized catechin concentrate at the time of centrifugation in the step (3) is 1 or more and less than 10.   A tea beverage containing the tea extract according to any one of claims 1 to 7.   The tea beverage according to claim 8, wherein the content of the polymerized catechin is 0.010 wt% to 0.100 wt%.

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