JP3447192B2 - Manufacturing method of clearing green tea beverage - Google Patents

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 green tea beverage, and more particularly to a method for producing a clear green tea beverage from which cloudiness components have been removed without impairing the flavor of green tea.

[0002]

2. Description of the Related Art In recent years, green tea beverages in which a can or a plastic container is filled with a green tea extract in a hermetically sealed container have been successively commercialized. However, the green tea beverage may lose its flavor due to the denaturation of the components contained in the green tea beverage for a long period of time, and may have turbidity such as suspended matter and precipitates. Such turbidity also causes a visual quality deterioration of the product to be felt, particularly in the case of a product contained in a transparent container such as a plastic container.

Therefore, various methods have been developed for suppressing the formation of turbidity in producing green tea beverages. It is considered that the formation of turbidity such as the suspended matter and the precipitate is mainly caused by denaturation due to association of polymer components such as polyphenols. In addition, the flavor tends to be impaired due to the formation of turbidity such as the suspended matter and the precipitate. Therefore, these methods are mainly developed from the viewpoint of how to remove the turbid component.

Specifically, as one of them, a method of filtering a green tea extract through an ultrafiltration membrane (Japanese Patent Laid-Open No. 4574/1992).
4). In the case of this method, although the formation of precipitates and the like is suppressed, there is a drawback that the flavor peculiar to green tea becomes poor because even the flavor component of green tea is removed by ultrafiltration.

Further, in Japanese Patent Laid-Open No. 4-311348, a method in which green tea is rapidly cooled by acidification with ascorbic acid to promote precipitate formation, filtered by centrifugal separation or the like, and then diatomaceous earth is added to clarify the method. Is disclosed. But,
In the case of this method as well, although the formation of precipitates is suppressed, there is a problem that the flavor of green tea is modified, which is considered to be caused by a sharp change in the pH of the solution.

Japanese Unexamined Patent Publication (Kokai) No. 8-228684 discloses a method of enzyme treatment with hemicellulase. When such enzyme treatment is used, green tea is added by adding a component other than green tea called enzyme. There is a problem that the original flavor changes.

Furthermore, a method comprising a step of decomposing a polymer component by extracting an active ingredient from a tea raw material and adding an acid component to obtain an acidic tea extract, and a step of homogenizing the acidic tea extract under high pressure (special characteristics Kaihei 7-170912). However, in the case of this method as well, there is a problem that the flavor of the green tea extract finally obtained is deteriorated because an acid or the like which is capable of decomposing the polymer component is added.

As described above, the conventional manufacturing method has a problem in that although the turbid component can be removed, the original flavor of green tea cannot be retained.

Therefore, in view of the above problems, it is an object of the present invention to provide a method for producing a clear green tea beverage from which turbid components have been removed without impairing the original flavor of green tea.

[0010]

In order to achieve the above-mentioned object, the method for producing a clear green tea beverage of the present invention comprises adjusting the dissolved oxygen concentration to 5 ppm or less, and adding an antioxidant within a range that does not affect the flavor. Using the added warm water of 50 to 100 ° C., a green tea extraction step of decoupling green tea leaves to extract green tea, and after the green tea extraction step, passing the green tea extract while rocking a filter of 80 to 200 mesh Then, the tea-husk removing step of removing the tea-husk from the green tea extract, and the green tea extract after the tea-husk removing step are passed through a cooler and cooled to about 10 ° C., and after cooling, at a speed of 5,000 rpm to 10,000 rpm. And a turbid component removing step of separating and removing the turbid component by performing centrifugal separation.

That is, in the method for producing a clear green tea beverage of the present invention, the concentration of dissolved oxygen is lowered, and an antioxidant is added to extract green tea while preventing the contained components from being oxidized. After extraction of green tea, the green tea extract is rapidly filtered using a filter provided with shaking to remove the tea leaves. By rapidly removing the tea leaves in this manner, it is possible to prevent the deterioration of the flavor and color tone when the tea leaves are mixed for a long time.

In the final turbidity component removing step, the green tea extract is cooled to about 10 ° C. in advance, and centrifugal separation is performed at a predetermined speed while precipitating precipitation of the turbidity components to remove the flavor components of green tea. The turbid component can be separated and removed while remaining.

Therefore, according to the method for producing a clear green tea beverage of the present invention, it is possible to produce a clear green tea beverage which does not form cloudiness without impairing the original flavor of green tea.

In the present invention, it is preferable to use sodium ascorbate in the concentration range of 0.5 to 2.0 ppm as an antioxidant in order to prevent oxidation in the manufacturing process. Since the addition of sodium ascorbate in this concentration range has almost no effect on pH, it does not deteriorate the flavor unlike the conventional production method.

By mixing 5% to 50% of gyokuro tea leaf with the green tea leaf, the flavor of green tea can be enriched. In addition, when gyokuro tea leaves are mixed, it is preferable that the warm water in the green tea extraction step is set to 50 to 70 ° C. to appropriately bring out the flavor of gyokuro.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below.

1. Green Tea Extracting Step As the green tea leaves used in the present invention, any tea leaves can be used alone or in combination. Preferably, gyokuro tea leaves are mixed and used to enhance the flavor of green tea.

Upon decocting the green tea leaves selected above, hot water is deaerated with a deaerator such as a dearator,
Reduces dissolved oxygen concentration. The dissolved oxygen concentration is preferably as low as possible, specifically 5 ppm
Adjust as follows. By lowering the dissolved oxygen concentration in this way, it is possible to prevent the green tea extract from being oxidized during the extraction and changing the flavor and color tone.

Furthermore, an antioxidant is added to the warm water to prevent the oxidation more reliably. As the antioxidant, for example, sodium ascorbate can be used. When using this sodium ascorbate,
It is preferably used in a concentration of 5 to 2.0 ppm. When used at this concentration, the pH of the green tea extract does not fluctuate significantly, so the flavor is not impaired.

The hot water temperature may be in the range of 50 ° C to 100 ° C, but when gyokuro tea leaves are mixed, it is set to 50 ° C to 70 ° C to effectively bring out the flavor peculiar to gyokuro. Is preferred.

The amount of tea leaves used can be in the range of 25 kg to 35 kg with respect to 1,000 liters of hot extraction water, and the amount can be appropriately increased or decreased within this range depending on the quality of tea leaves and the like.

The extraction time is preferably in the range of 3 minutes to 10 minutes, and the time can be appropriately adjusted depending on the tea leaves used in this range.

2. Tea husk removing step It is necessary to quickly remove the tea husk from the green tea extract in order to prevent a change in flavor and a change in color due to the mixture of tea husks.

The removal of the tea leaves is carried out by passing the green tea extract through a filter of 80 to 200 mesh immediately after extraction. In order to enable more rapid filtration of the green tea extract, the filter is subjected to rocking, such as sliding movement or tilting movement. The amplitude of the slide motion and the tilt angle of the tilting mobility can be appropriately adjusted according to the size of the filter to be used. For example, the tilting angle of the tilting mobility should be in the range of 5 to 30 ° C. You can

By thus swinging the filter, it is possible to prevent the filter from being clogged due to the accumulation of the tea leaves on the filter. In addition, adding rocking can break the surface tension of the green tea extract when passing through the filter and increase the filtration rate.

3. Turbidity component removing step The green tea extract after the tea leaves have been removed in the above is passed through a cooler such as a plate cooler or the like to be rapidly cooled to about 10.degree. If the green tea extract is maintained at the temperature at the time of extraction, the oxidation reaction is likely to proceed and the flavor is deteriorated. Therefore, it is preferable to first lower the temperature to suppress the progress of the oxidation reaction and the like. In addition, here, by cooling to about 10 ° C., the turbid component contained in the green tea extract can be easily precipitated in the centrifugation operation described later.

As the cooling unit, an existing cooling device such as a plate cooler can be arbitrarily selected and used. Here, when using a plate cooler,
As the coolant inside the plate cooler, chilled water of about 5 ° C. or antifreeze liquid of 5 ° C. or less is used. When using chilled water at about 5 ° C, the temperature of the green tea extract is adjusted by adjusting the flow rate of the green tea extract and allowing the green tea extract to remain on the plate cooler for about 10 to 20 seconds. 50-10
It is possible to cool 0 ° C to about 10 ° C. Then
The cooled green tea extract is poured into a centrifuge, and the causative component of turbidity is removed by centrifugation.

When centrifugation is performed, 5,000 rp
Centrifugation is performed at a rotation speed of m to 10,000 rpm. When a continuous centrifuge is used, the flow rate is 8,000 liters / hour to 20,000 liters / hour at the number of revolutions.
Adjust to processing speed in the range of time.

It should be noted that 10% of green tea extract was added before centrifugation.
If it is not cooled down to about 0 ° C., the turbid component cannot be sufficiently removed under the above-mentioned centrifugation conditions.

However, in the present embodiment, the green tea extract is cooled to about 10 ° C. before the centrifugation operation to facilitate precipitation of turbid components. Therefore, the normal centrifugation processing speed (flow rate 8,000) is used. It is possible to remove the turbid component from 1 liter / hour to 20,000 liter / hour.

As described above, with a simple centrifuge,
By efficiently separating and removing the turbid component, it becomes possible to obtain a tea extract suitable for long-term storage.

The clarified tea extract thus obtained is filtered using a filter aid such as diatomaceous earth, if necessary, and microfiltered with a mesh size of about 0.5 to 5 microns. And so on.

The clarified green tea extract obtained by the above operation can be made into a green tea extract which can withstand further storage by adding a compound having an antioxidant effect such as ascorbic acid, Thereafter, the pH of the green tea extract is adjusted to about 6.0 to 7.0 with sodium bicarbonate, sodium ascorbate, sodium carbonate, etc., and the can, bottle,
A green tea extract suitable for filling a plastic container such as a PET bottle can be obtained.

Further, the series of steps in the present embodiment may be carried out in a nitrogen stream in order to prevent oxidation of the tea extract.

[0035]

EXAMPLES Next, the present invention will be specifically described based on examples, but the present invention is not limited to the examples.

[Example 1] A mixed tea leaf of 10 kg of gyokuro and 20 kg of sencha was used for 6 minutes with 1,000 liters of warm water at 60 ° C to which a dissolved oxygen content of 5 ppm or less was added using a dearator and 1 ppm of sodium ascorbate was added. Extract. Immediately after the extraction, the tea extract and the tea leaves are separated, so that the wire mesh surface is separated by a separator of a 150-mesh wire mesh while being swung 4 times while making an inclination angle of about 15 degrees to obtain a tea extract. The obtained extract is passed through a plate cooler using chilled water as a refrigerant and cooled to 10 ° C.,
Centrifugation was performed at a rotation speed of 6,000 rpm to obtain a clarified tea extract. The obtained green tea extract is hydrated with twice the amount of water as the green tea extract and vitamin C is added to 500 ppm.
It was added at a concentration and adjusted to pH 6.5 with sodium bicarbonate to obtain a green tea extract for container pawls.

Example 2 A mixed tea leaf of 15 kg of gyokuro and 15 kg of sencha was extracted for 5 minutes with 1,000 liters of warm water at 70 ° C. with a dissolved oxygen content of 5 ppm or less using a dearator and 1 ppm of sodium ascorbate added. To do. Immediately after the extraction, the tea extract and the tea leaves are separated, so that the wire mesh surface is separated by a separator of a 150-mesh wire mesh while being swung 4 times while making an inclination angle of about 15 degrees to obtain a tea extract. The obtained extract is passed through a plate cooler using chilled water as a refrigerant and cooled to 10 ° C.,
Centrifugation was performed at a rotation speed of 6,000 rpm to obtain a clarified tea extract. The obtained green tea extract is hydrated with twice the amount of water as the green tea extract and vitamin C is added to 500 ppm.
It was added at a concentration and adjusted to pH 6.5 with sodium bicarbonate to obtain a green tea extract for container pawls.

Comparative Example 1 Mixed tea leaves of 15 kg of gyokuro and 15 kg of sencha were extracted for 5 minutes with 1,000 liters of warm water at 60 ° C. Immediately after the extraction, in order to separate the tea extract and the tea leaves, a tea mesh extract is obtained by separating with a separator of a 150 mesh wire mesh. The obtained extract was passed through a plate cooler using chilled water as a refrigerant and cooled to 10 ° C.
Centrifugation was performed at a rotation speed of 0 rpm to obtain a clarified tea extract. The green tea extract thus obtained was prepared by adding twice the amount of water to the green tea extract, adding vitamin C at a concentration of 500 ppm, and adjusting the pH to 6.5 with sodium bicarbonate to obtain a green tea extract for container pawls.

[Comparative Example 2] Mixed tea leaves of 15 kg of gyokuro and 15 kg of sencha were extracted for 5 minutes with 1,000 liters of warm water at 60 ° C. Immediately after the extraction, in order to separate the tea extract and the tea leaves, a tea mesh extract is obtained by separating with a separator of a 150 mesh wire mesh. Pass the resulting extract through a plate cooler, 3
After cooling to 0 ° C., centrifugation was performed at a rotation speed of 7,000 rpm to obtain a clarified tea extract. The resulting green tea extract was prepared by adding twice the amount of water as the green tea extract, adding vitamin C at a concentration of 500 ppm, and adding sodium bicarbonate to pH 6.5.
To obtain a green tea extract for the container claws.

[Judgment] The tea extracts obtained in the above Examples and Comparative Examples were sealed in PET bottles, stored at 30 ° C. for 3 months, and subjected to a sensory test by 5 panelists.

In the sensory test, the presence or absence of deterioration of flavor (taste, fragrance), turbidity, precipitation, etc. was judged and comprehensive evaluation was conducted.

[0042]

[Table 1]

[0043]

As described above, according to the method for producing a clear green tea beverage of the present invention, turbid components are efficiently removed by a simple centrifugation operation, so that the flavor of green tea can be preserved when stored for a long period of time. It does not spoil, nor does it form a precipitate or turbidity.

Therefore, according to the method for producing a clear green tea beverage of the present invention, it is possible to produce a clear green tea beverage suitable as a product of a green tea beverage contained in a can or a plastic container.

Continuation of front page (56) Reference JP-A-4-311348 (JP, A) JP-A-6-343389 (JP, A) JP-A-5-168407 (JP, A) JP-A-6-105654 (JP , A) JP 2-13348 (JP, A) JP 6-311847 (JP, A) JP 62-126934 (JP, A) JP 8-228684 (JP, A) JP 8-126472 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A23F 3/20 A23F 3/16

Claims (3)

(57) [Claims] 1. The dissolved oxygen concentration is adjusted to 5 ppm or less,
An antioxidant was added to the extent that it does not affect the flavor 5
A green tea extraction step of extracting green tea by decocting green tea leaves using warm water of 0 to 100 ° C., and after the green tea extraction step, while passing through a filter of 80 to 200 mesh, the green tea extract is passed to obtain green tea. A tea-husk removing step of removing tea-husks from the extract, and passing the green tea extract after the tea-husk removing step through a cooler to cool to about 10 ° C., and after cooling, 5,000 rpm to 10,
A method for producing a clear green tea beverage, which comprises a turbid component removal step of separating and removing a turbid component by performing centrifugation at a speed of 000 rpm. 2. The method for producing a clear green tea beverage according to claim 1, wherein the antioxidant is 0.5 to 2.0 ppm sodium ascorbate. 3. The clarifier according to claim 1, wherein the green tea leaves contain 5% to 50% of gyokuro tea leaves, and the warm water in the green tea extraction step is 50 to 70 ° C. Method for producing green tea beverage.