JPH10290660A - Production of clear green tea beverage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a clear green tea beverage capable of preventing formation of turbidity without impairing characteristic taste of green tea. SOLUTION: A green tea is extracted from green tea leaves containing 5-50% of tea leaves of green tea of the highest quality by using warm water by boiling at 50-70 deg.C for 5-15 minutes. After the extraction of the green tea, the extracted solution of green tea is successively passed through a filter of 10-30 meshes and a filter of 100-200 meshes to remove used tea leaves from the extracted solution of green tea. After the removal of the used tea leaves, the extracted solution of green tea is poured into a centrifugal separator while cooling the solution to about 30 deg.C. A turbid component is removed at 5,000-10,000 rpm number of revolutions at 3,000 liter/hour to 6,000/liter/hour flow velocity to recover the objective clear green tea beverage as a supernatant liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 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 turbid components are removed without impairing the flavor of green tea.

[0002]

2. Description of the Related Art In recent years, green tea beverages in which a green tea extract is filled in a can or a plastic container in a sealed container have been produced one after another. However, green tea beverages may lose flavor due to denaturation of contained components and may form turbidity such as suspended solids and sediment during long-term storage. Such turbidity can cause visual quality deterioration of the product, especially in the case of a product contained in a transparent container such as a plastic container.

[0003] In order to commercialize a green tea beverage, various methods have been developed to suppress the formation of this turbidity. The formation of turbidity such as suspended matters and precipitates is considered to be mainly caused by denaturation due to association of polymer components such as polyphenols. In addition, the flavor tends to be impaired with the formation of turbidity such as suspended matter and sediment. Therefore, these methods have been developed mainly from the viewpoint of how to remove this turbid component.

[0004] Specifically, as one of the methods, a method of filtering a green tea extract with an ultrafiltration membrane (JP-A-4-4574).
No. 4 publication). In the case of this method, although the formation of precipitates and the like is suppressed, there is a disadvantage that the flavor component of green tea is poor because the flavor component of green tea is removed by ultrafiltration.

Japanese Patent Application Laid-Open No. 4-31348 discloses a method in which green tea is quenched by acidification with ascorbic acid to promote the formation of precipitates, filtered by centrifugation or the like, and then filtered by adding diatomaceous earth for clarification. 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 denatured, which is considered to be caused by a sudden change in the pH of the solution.

Japanese Patent Application Laid-Open No. Hei 8-228684 discloses a method in which an enzyme treatment is carried out with hemicellulase. When such an enzyme treatment is used, green tea is added by adding a component other than green tea called an enzyme. There is a problem that the original flavor changes.

Further, a method comprising the steps of decomposing a polymer component by extracting an active ingredient from a tea raw material and adding an acid component to obtain an acidic green tea extract, and a step of subjecting the acidic green tea extract to high-pressure homogenization (particularly). No. Hei 7-170912). However, also in this method, there is a problem that the flavor of the finally obtained green tea extract is deteriorated because an acid or the like that can decompose the polymer component is added.

As described above, in the conventional production method, although the turbid component can be removed, there is a problem that the original flavor of green tea cannot be maintained.

[0009] In view of the above problems, an object of the present invention is 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 object, a method for producing a clear green tea beverage according to the present invention comprises:
Green tea leaves containing 50% to 50% with warm water at 50 to 70 ° C
A green tea extraction step of extracting green tea brewed for 15 minutes, and after the green tea extraction step, a green tea extract is sequentially passed through a 10-30 mesh filter and a 100-200 mesh filter to remove tea husks from the green tea extract. After the step and the tea husk removing step, the green tea extract is poured into a centrifugal separator while cooling to about 30 ° C.
3,000 liters / hour under a rotation speed of 00 rpm
And a turbid component removing step of separating and removing the turbid component by separating and collecting the supernatant at a flow rate of 6,000 liters / hour.

That is, the method for producing a clear green tea beverage of the present invention can remove turbid components by removing tea husks from the green tea extracted in the green tea extraction step and then centrifuging the green tea under appropriate conditions. It becomes possible. After the green tea extraction step, a series of steps of the tea husk removal step and the turbid component removal step are quickly performed, thereby preventing the deterioration of flavor.

Therefore, according to the method for producing a clarified green tea beverage of the present invention, a clarified green tea beverage that does not form turbidity can be produced without impairing the original flavor of green tea.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

1. Green Tea Extraction Step The tea leaves of green tea used in the present invention have a gyokuro content of 5 to 50.
% Green tea leaves can be blended arbitrarily according to the flavor to be produced. By mixing the gyokuro tea leaves, a flavorful green tea extract can be obtained. Therefore, by increasing the amount of mixed gyokuro tea leaves, a richer flavor can be obtained from the green tea extract.

In order to extract green tea by infusing the green tea leaves blended in the above, it is carried out in hot water at a hot water temperature of 50 ° C. to 70 ° C. for 3 minutes to 10 minutes. Green tea leaves other than Gyokuro tea leaves are 80 ℃ ～ 1
It is preferable to incense at 00 ° C, but when gyokuro tea leaves are contained, the flavor unique to gyokuro can be effectively extracted at a hot water temperature of 50 ° C to 70 ° C. Therefore, it is desirable to extract at a temperature suitable for the tea leaves blended above.

The amount of tea leaves used is 25 kg to 35 kg with respect to 1,000 liters of the extracted hot water, and the used amount can be appropriately increased or decreased according to the quality of the tea leaves and the like. The warm water to be used may be simple warm water, but in order to prevent a change in flavor due to oxidation during the operation, warm water subjected to an antioxidant treatment may be used. The hot water that has been subjected to the antioxidant treatment is, for example, hot water to which salts such as sodium ascorbate are appropriately added within a range that does not change the flavor, or hot water obtained by boiling the hot water or deaerated using a deaerator (a deaerator). Is mentioned.

2. Step of removing tea husks The step of removing tea husks from the green tea extract needs to be performed promptly in order to prevent changes in flavor and color tone due to the mixture of tea husks. Therefore, it is desirable to perform the following two steps. That is, a step of filtering using a filter capable of separating large tea leaves in advance and a step of filtering using a filter capable of collecting remaining fine tea leaves are sequentially performed.

As a filter from which the above-mentioned large tea husks can be collected, specifically, a filter of about 10 to 30 mesh may be used. Further, as a filter capable of collecting fine tea leaves, a filter of about 100 to 200 mesh may be used. In this way, by separating large tea leaves in advance and then collecting the remaining fine tea leaves, the tea leaves can be quickly removed without causing clogging of the filter. Therefore, it is possible to prevent a change in flavor and a change in color tone caused by the mixture of tea husks for a long time.

3. Turbid component removal step The green tea extract from which the tea husks have been removed in the above is rapidly cooled to about 30 ° C. by passing through a cooler such as a plate cooler. If the temperature of the green tea extract is maintained at the temperature at the time of extraction, the oxidation reaction is likely to proceed, which causes the flavor to be impaired. Therefore, it is preferable to first lower the temperature to suppress the progress of the oxidation reaction and the like.

Next, the cooled green tea extract is poured into a centrifuge, and components causing turbidity are removed by centrifugation.
The centrifuge used here is preferably a continuous centrifuge. By using a continuous centrifugal separator, turbid components can be quickly removed from the extract liquid that is sequentially adjusted, and thus a large amount of clear green tea beverage can be produced without impairing the flavor and the like.

In the case of performing continuous centrifugation, 5,000
Centrifugation is performed at a rotation speed of 10 rpm to 10,000 rpm, and the supernatant is collected at a flow rate of 3,000 liters / hour to 6,000 liters / hour.

Conventionally, in a continuous centrifugal separator used for beverages and foods, a rotation speed of 5,000 to 10,000 rpm can be obtained, but the separation processing capacity is at least 8,000.
0 liters / hour to a maximum of 20,000 liters / hour.
0 liters / hour to 6,000 liters / hour were out of range. In the present invention, by making it possible to adjust this flow rate, particularly the flow rate in the lowest range, to a lower value,
It has become possible to keep the green tea extract in the centrifuge longer. As a result, turbid components could be separated and removed even by a simple centrifuge, and it was possible to obtain a green tea extract suitable for long-term storage.

The clarified green tea extract thus obtained may be subjected to filtration using a filter aid such as diatomaceous earth or microfiltration having a mesh size of about 0.5 to 5 microns, if necessary. It can be carried out.

By adding a compound having an antioxidant effect such as ascorbic acid to the clarified green tea extract obtained by the above operation, a green tea extract that can withstand long-term storage can be obtained. Then, the pH of the green tea extract was adjusted to about 6.0 to 7.0 with baking soda, sodium ascorbate, sodium carbonate, or the like, and the
A green tea extract suitable for filling a plastic container such as a PET bottle can be obtained.

The step of the present invention is preferably performed in a nitrogen stream to prevent oxidation of the green tea extract.

[0026]

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

[Example 1] 10 kg of gyokuro and 20 kg of green tea
Is extracted for 8 minutes with 1,000 liters of hot water obtained by cooling boiling water to 60 ° C. Immediately after the extraction, the green tea extract is passed through a separator to separate the tea husks. This separator is made of a double wire mesh, the upper wire mesh is made of 20 mesh, and the lower wire mesh is made of 150 mesh. By passing the green tea extract through this separator, a green tea extract from which tea husks have been removed is obtained.

Next, the obtained green tea extract was cooled to 30 ° C. through a plate cooler, and then 8,000 rpm
Centrifugation was performed at a flow rate of 5,000 liters / hour at a rotation speed of m to obtain a clarified green tea extract.

The obtained green tea extract was further passed through microfiltration (trade name: Millipore filter) having an eye size of 0.5 μm, and then water of twice the amount of green tea extract was added to obtain vitamin C. It was added at a concentration of 500 ppm and adjusted to pH 6.5 with baking soda to obtain a green tea extract for packing.

Example 2 20 kg of gyokuro and 10 kg of green tea
Is extracted with 1,000 liters of hot water obtained by cooling boiling water to 50 ° C. for 10 minutes. Immediately after the extraction, the green tea extract and the tea shell are separated by the above-described double wire mesh separator to obtain a green tea extract.

The obtained green tea extract was cooled to 25 ° C. through a plate cooler, and then centrifuged at 10,000 rpm and the flow rate was adjusted so that the flow rate was 4,000 liters / hour. A clarified green tea extract was obtained.

The obtained green tea extract was prepared by adding twice the amount of water to the green tea extract, adding vitamin C at a concentration of 500 ppm, adjusting the pH to 6.5 with sodium bicarbonate, and extracting the green tea extract for packaging. Obtained.

Comparative Example 1 30 kg of green tea was extracted with 1,000 liters of hot water at 80 ° C. for 4 minutes. Immediately, the green tea extract was separated from the tea husks using a 150-mesh wire mesh separator to extract green tea. Obtain a liquid.

The obtained green tea extract was cooled to 30 ° C. through a plate cooler, and then centrifuged at a rotation speed of 8,000 rpm and a flow rate adjusted to 10,000 liter / hour. A green tea extract was obtained.

The obtained green tea extract was further passed through a microfiltration (commercial product: Millipore filter) having an eye size of 0.5 μm, and then water was added twice as much as the green tea extract to obtain vitamin C.
Was added at a concentration of 500 ppm, and the pH was adjusted to 6.5 with sodium bicarbonate to obtain a green tea extract for packing.

COMPARATIVE EXAMPLE 2 30 kg of green tea was extracted with 1,000 liters of hot water at 85 ° C. for 3 minutes, and immediately separated from the green tea extract and the tea husk by a 150 mesh wire mesh separator. Get.

The obtained green tea extract was cooled to 25 ° C. through a plate cooler, and then centrifuged at 10,000 rpm and a flow rate of 15,000 liters / hour to obtain a green tea extract. Was.

The obtained green tea extract was prepared by adding twice the amount of water to the green tea extract, adding vitamin C at a concentration of 500 ppm, adjusting the pH to 6.5 with sodium bicarbonate, and preparing the green tea extract for packing. Obtained.

Example 3 The green tea extracts obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were compared and judged. For the determination, each extract was sealed in a PET bottle and stored at 30 ° C. for 3 months, and then a sensory test was conducted by five panelists.

In the sensory test, deterioration of flavor (taste / aroma), presence / absence of turbidity / precipitation was determined and comprehensively evaluated. Table 1 shows the results.

[0041]

[Table 1]

[0042]

As described above, according to the present invention, by removing turbid components by centrifugation, it is possible to form a precipitate or turbid without losing the flavor when stored for a long period of time. No clearing green tea beverage is obtained.

As a result, a clear green tea beverage suitable as a product of a green tea beverage contained in a can or a plastic container can be manufactured.

Claims (1)

[Claims] 1. 50 green tea leaves containing 5 to 50% of gyokuro tea leaves
A green tea extraction step of extracting green tea by brewing for 5 to 15 minutes using warm water of ~ 70 ° C, After the green tea extraction step, the green tea extract is sequentially passed through a 10-30 mesh filter and a 100-200 mesh filter, A tea husk removing step of removing the tea husk from the green tea extract, and after the tea husk removing step, the green tea extract is poured into a centrifugal separator while being cooled to about 30 ° C., and 5,000 to 10,000.
3,000 liters / hour ~ 60 under rpm
A method for producing a clarified green tea beverage, comprising a step of removing a turbid component by separating and collecting a supernatant at a flow rate of 00 liter / hour.