JP2008035707A - Method for producing separated liquid from used tea leaves - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a separated liquid from used tea leaves enabling efficient removal of used tea leaves from extract liquid produced by using minute tea leaves or soft tea leaves. <P>SOLUTION: The method for producing a separated liquid from used tea leaves comprises the following process: supplying soft tea leaves 1 such as minute tea leaves containing 50-100 wt.% of fractions passing through the sieve of 20 mesh into an extraction device 11 to produce extract liquid 3 in the extraction device 11; passing the extract liquid 3 in the extraction device 11 through a screen 14 comprising a perforated panel to eliminate used tea leaves 6 in the extract liquid 3 by the screen 14; receiving the extract liquid 3 passing through the screen 14 and charging the liquid into a tank 15 to produce separated liquid 5 from used tea leaves. The perforated panel forming the screen 14 comprises a punching metal where the rate of hole area of holes 14a is 20-50%, and the inner diameter of each of the holes 14a is 1.5-2.5 mm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a tea-based beverage, and more particularly to a method for producing a tea husk separation liquid that can easily separate tea husk from an extract containing tea leaves, which has been difficult to separate and remove by conventional methods.

  In recent years, tea-based beverages such as green tea, oolong tea, and black tea have been increased in dosage, and products having various characteristics have been released.

  A method for producing a tea-based beverage will be briefly described. First, tea leaves and hot water are placed in an extraction tank or extraction device corresponding to a teapot for home use, and then the tea leaves are removed with a screen corresponding to a tea strainer. Here, the extract from which the tea leaves have been removed is passed through a heat exchanger to lower the temperature, and then subjected to a centrifugal separation treatment, and the tea leaves are further removed to increase the clarity. The clarified extract is transferred to a mixing tank, sterilized after performing a mixing operation such as pH adjustment, and filled into a container. At this time, when filling a transparent container such as a PET bottle, final filtration is performed once more using a precision filter, if necessary. It is important that these beverage manufacturing processes be performed smoothly at a consistently determined speed. If any process is delayed, not only will the production efficiency of the factory decrease, but the quality of the extract may be degraded.

  However, in reality, depending on the tea leaves used, clogging may occur in a solid-liquid separation process using a screen (hereinafter referred to as a screen separation process), which is the first solid-liquid separation process. For example, clogging is likely to occur in the case of fine tea leaves or soft tea leaves such as new green tea or high-quality gyokuro. With the recent diversification of commodities, the need to use such tea leaves for tea-based beverages has increased, so a method for solving this problem is expected.

  In the past, in order to separate a raw material koji such as green tea and oolong tea from an extract, a screen inclined in a 32 to 350 mesh shape is proposed (see Patent Document 1). However, this method improves the extraction process in which tea leaves have been conventionally packed, and is not intended to improve filterability. Therefore, clogging occurs when tea leaves that are difficult to separate and remove are used. Furthermore, such specially shaped screens are difficult to use for general purposes and are not practical.

  On the other hand, there is a method in which an extract having tea leaves including gyokuro tea leaves is sequentially passed through a 10 to 30 mesh filter and a 100 to 200 mesh filter to remove tea shells from the extract (see Patent Document 2). This method only shows the screen separation conditions used in the production process of a normal tea-based beverage, and when tea leaves that are difficult to separate and remove are used, clogging occurs and is not practical.

Furthermore, a method of filtering the green tea extract with an ultrafiltration membrane is disclosed (see Patent Document 3). Moreover, a diatomaceous earth filtration method is disclosed as a post-process of filtration by centrifugation (see Patent Document 4). However, these methods relate to a final filtration step for suppressing precipitation after storage of the product, and not to a screen separation step.
JP 62-126934 A JP-A-10-290660 JP-A-4-45744 JP-A-4-31348

  The present invention has been made in consideration of these points. When filtering an extract containing tea leaves that are difficult to separate and remove by conventional techniques, such as soft tea leaves such as fine tea leaves, green tea new tea and high-quality gyokuro, etc. Furthermore, it aims at providing the manufacturing method of the tea-shell separation liquid which can be performed efficiently in a short time, without causing clogging.

  The present invention includes a step of supplying tea leaves together with water into an extraction device, a step of mixing these tea leaves and water in the extraction device to produce an extract containing tea leaves, and a number of extracts in the extraction device. A step of removing tea leaves in the extract through a screen made of a perforated plate including holes, and a step of supplying the extracted liquid that has passed through the screen to a tank. The perforated plate has a hole area ratio of 20 It is a manufacturing method of the tea-shell separation liquid characterized by being -50% and the internal diameter of each hole being 1.5 mm-2.5 mm.

  The present invention is a process of supplying one or two kinds of tea leaves selected from fine tea leaves containing 50 to 100% by weight of a 20-mesh-passed fraction, green tea new tea leaves, and high-quality gyokuro tea leaves together with water into the extraction device. And a step of producing an extract containing tea leaves by mixing these tea leaves and water in the extractor, and passing the extract in the extractor through a screen made of a perforated plate having a large number of holes in the extract. And a step of receiving the extraction liquid through the screen and supplying it to the tank, the perforated plate has a hole opening ratio of 20 to 50%, and the inner diameter of each hole is 1.5 mm to It is a manufacturing method of the tea-shell separation liquid characterized by being 2.5 mm.

  The present invention is the method for producing a tea-shell separation liquid, wherein each hole of the perforated plate is a round hole having an inner diameter of 2 mm.

  In the present invention, after passing the extract in the extraction device through a screen made of a perforated plate, the extract is further passed through an additional screen to remove tea shells in the extract and supply the extract to the receiving tank. Is further provided.

  The present invention is the method for producing a tea-shell separation liquid, wherein the perforated plate is made of a metal plate including a large number of holes formed by punching.

  As described above, according to the present invention, extraction is performed by using a screen made of a perforated plate having a hole opening ratio of 20 to 50% and an inner diameter of each hole of 1.5 mm to 2.5 mm. The tea leaves in the liquid can be effectively removed. In this case, even when using soft tea leaves that are difficult to separate and remove compared to conventional screens made of wire mesh, etc., the tea leaves in the extract are efficiently removed in a short time without causing clogging. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 and FIG. 2 are diagrams showing an embodiment of a method for producing a tea leaves separation liquid according to the present invention.

  First, with reference to FIG. 1 and FIG. As shown in FIG. 1 and FIG. 2, an apparatus 10 for producing a tea husk separation liquid is supplied with tea leaves 1 and water 2, and these tea leaves 1 and water 2 mix to obtain an extract 3, A steam jacket 12 that covers the extraction device 11 and adjusts the temperature of water inside the extraction device 11, a screen device 13 that is disposed below the extraction device 11 and has a screen 14 as a bottom plate, and provided below the screen device 13. And a receiving tank 15. An additional screen 16 is installed between the screen 14 of the screen device 13 and the receiving tank 15.

  Furthermore, in the extraction device 11, a stirrer 11a for mixing the tea leaves 1 and the water 2 is provided. Further, the extraction device 11 and the steam jacket 12 are rotated and inclined by a rotation mechanism (not shown), and the extraction liquid 3 in the extraction device 11 can be supplied into the screen device 13.

  By the way, the screen 14 that forms the bottom plate of the screen device 13 is made of a perforated plate (punching metal) such as a metal plate including a large number of holes 14a, and the aperture ratio of the holes 14a is 20 to 50%. The perforated plate 14 is made of a metal plate such as stainless steel, and each hole 14a is a round hole having an inner diameter of 1.5 mm to 2.5 mm, preferably about 2 mm (FIG. 2).

  In FIG. 2, the perforated plate 14a of the screen has holes 14a made of round holes, and the holes 14a are arranged in a 60 ° zigzag pattern.

At this time, the aperture ratio F is
F = 90.6D ² / P ²
D = Inner diameter of hole P = Center pitch

  The additional screen 16 disposed below the screen 14 has substantially the same structure as the screen 14, but the hole of the additional screen 16 is a round hole having an inner diameter of about 1 mm.

  The additional screen 16 below the screen 14 is not necessarily provided.

  Next, a method for producing the tea husk separation liquid is described.

  First, as shown in FIG. 1, tea leaves 1 and water 2 are supplied into the extraction device 11.

  This tea leaf 1 is composed of one or two kinds of tea leaves selected from fine tea leaves containing 50 to 100% by weight of a 20-mesh passing fraction, green tea new tea, and high-quality gyokuro tea leaves.

  Specifically, tea leaves are leaves of plants such as green tea, oolong tea, black tea, black tea, etc. that are obtained by processing fresh leaves of Camellia sinensis, and are extracted from plant leaves such as persimmon tea, Tochu tea, and rooibos tea. Any liquid can be taken by humans. In particular, as described above, tea leaves that could not be separated and removed from the conventional extract, for example, tea leaves containing soft tea leaves such as fine tea leaves, green tea new tea, and high-quality gyokuro are suitable.

  The fine tea leaf here refers to a tea leaf in which a 20-mesh passing fraction occupies 50 to 100% by weight or more. While this fine tea leaf is obtained by pulverization with a normal pulverizer, so-called powdered tea that is produced as a secondary product in the tea-making process can also be targeted.

  It is not always essential to use these tea leaves, but examples of tea leaves that clearly show the effects of the present invention when used are shown as preferred examples.

  Any of the above-described tea leaves 1 are soft, and when the tea leaves 6 in the extract are removed with a conventional wire mesh screen, they cannot be removed efficiently as described later. On the other hand, according to the present invention, even when such a soft tea leaf 1 is used, the tea shell 6 can be efficiently removed without causing clogging. This point will be described later.

  Next, in the extraction apparatus 11, these tea leaves 1 and water 2 are stirred and mixed using the stirrer 11a, the tea leaves 1 are extracted, and the extract 3 containing the tea leaves 6 is manufactured.

  There is no particular limitation on the extraction of tea leaves 1, and at the industrial level, extraction is performed in the extraction apparatus 11 using water 2 that is 10 to 100 times the tea leaf weight in about 5 to 10 minutes as described above.

  Moreover, there is no restriction | limiting in particular in the temperature of water, What is necessary is just to use normal temperature-boiling water according to the flavor requested | required.

  Next, the extraction device 11 and the steam jacket 12 are rotated and tilted by a rotation mechanism (not shown), and the extraction liquid 3 in the extraction device 11 is poured into the screen device 13 side. At this time, the extract 3 passes through the screen 14 of the screen device 13.

  As the screen 14 made of a perforated plate (punched metal) used in the present invention, a screen having a hole area ratio of 50% or less can be used. Note that the aperture ratio refers to the area of the aperture portion in the area of the screen 14. Among these, as described above, the screen 14 having the round hole 14a having an inner diameter of 2 mm is preferable. Furthermore, the screen 14 having a 60 degree staggered round hole 14a is most preferable. The material of the screen 14 is optimally made of stainless steel in terms of hygiene.

  By passing the extract 3 through the screen 14, the tea leaves 6 contained in the extract 3 can be effectively removed by the screen 14. In this case, even when the extraction liquid 3 is manufactured using the soft tea leaves 1 as described above, the extraction liquid 3 is not clogged by the screen 14 made of a perforated plate made of punching metal. The inside tea shell 6 can be effectively removed.

  Furthermore, the extraction liquid 3 that has passed through the screen 14 can be filtered again using the additional screen 16 to remove the tea husk 6 more effectively, and the extraction liquid 3 that has passed through the additional screen 16 is received by the receiving tank 15. To become a tea husk separation liquid 5. There is no particular limitation on the additional screen 16 in the second stage, and a normal general-purpose wire mesh or a wedge wire that is a screen other than a perforated plate may be used. Preferably, an additional screen 16 having a smaller hole diameter than the first stage screen 14 is used.

  Although the theory of the present invention has not yet been clarified, by using the screen 14 made of a perforated plate having a specific aperture ratio, fine powder which is a cause of clogging passes through the screen, and the tea shell 6 itself on the screen is laminated. Thus, it is assumed that filtration becomes a filter layer and as a result, filtration without clogging becomes possible. If the hole diameter of the perforated plate is less than 1.5 mm, fine tea will be clogged and filtration will be hindered, and if it is greater than 2.5 mm, the tea bowl discharge rate will increase. On the other hand, from the structure of the wire mesh, it is determined that fine powder tea stays in the middle of the mesh and causes clogging.

  After that, the tea leaves separation liquid 5 in the receiving tank 15 passes through a heat exchanger and a centrifuge as necessary, and then proceeds to the blending process. Furthermore, the obtained preparation liquid is filled into a container through a sterilization step and, if necessary, a final filtration step to become a product.

  As described above, according to the present embodiment, when removing the tea husk 6 in the extract 3, the conventional separation and removal is performed by filtering using the screen 14 made of a perforated plate having an open area ratio of 50% or less. Even in the case of the extract 3 using the soft tea leaves 1 that are difficult to squeeze, the tea leaves 6 can be efficiently separated in a short time without causing clogging.

  The extraction device 11 need not be limited to the kneader shown in FIG. 1, and the same effect can be obtained by using a screen 14 made of a perforated plate after extraction using a column type extraction device or the like as the extraction device 11. .

  Specific examples of the present invention will be described below.

  Extraction including tea husk 6 by adding 200 g of powdered tea (20 mesh passing fraction 80 wt%) to 6000 g of hot water at 70 ° C. and extracting for 5 minutes with occasional stirring in an extraction device consisting of a container without a stirrer Liquid 3 was produced.

  Next, a 150 mm diameter vinyl placed on a screen 14 made of a square perforated plate (aperture ratio 30%, 2 mm diameter round hole, 60 degree zigzag type) with 30 cm sides of the extract 3 containing the tea leaves 6 The solution was put into a pipe and left on the screen 14 for 3 minutes to drain liquid.

  The height of the tea husk 6 on the screen 14 after the end of the liquid draining was 54 mm (theoretical value 55 mm), and the recovery rate of the tea husk separation liquid 5 by the screen 14 was 89.3%. Within the expected time, the tea leaves 6 could be separated smoothly. The recovery rate of the tea husk separation liquid 5 was also sufficiently high.

Comparative Examples 1 and 2

  Experiments were performed in the same manner as in Example 1 except that the screen was replaced with a 20-mesh general-purpose wire mesh (Comparative Example 1), or the screen was replaced with a wedge wire with a slit of 0.5 mm (Comparative Example 2).

  As a result, in Comparative Example 1, the height of the tea husk 6 on the screen was 108 mm, and the recovery rate of the extract by the screen was 61.5%. In Comparative Example 2, the height of the tea husk 6 on the screen was 77 mm, and the recovery rate of the tea husk separation liquid 5 by the screen was 80.4%. In Comparative Examples 1 and 2, it was found that sufficient liquid drainage could not be performed.

  Using a small extractor 11 having a stirrer 11a, 2.5 kg of powdered tea (20 mesh passing fraction 70% by weight) was added to 75 kg of 70 ° C. warm water, and then extracted for 5 minutes with occasional stirring by the stirrer 11a. Thus, an extract 3 containing tea husk 6 was produced.

Next, the extract 3 containing the tea husk 6 was subjected to solid-liquid separation with a screen 14 made of a perforated plate similar to Example 1 having an area of 0.022 m ² , and left on the screen 14 for 3 minutes to drain the liquid.

  The height of the tea husk 6 on the screen 14 after the end of the liquid drainage was 52 mm (theoretical value 55 mm), and the recovery rate of the tea husk separation liquid 5 by the screen 14 was 88.5%. Within the expected time, the tea leaves 6 could be separated smoothly. The recovery rate of the tea husk separation liquid 5 was also sufficiently high.

  Extraction containing tea husk 6 by adding 200 g of powdered tea (20 mesh passing fraction 85 wt%) to 6000 g of hot water at 70 ° C. and extracting for 5 minutes with occasional stirring in an extraction device consisting of a container without a stirrer Liquid 3 was produced.

  Next, the extract 3 containing the tea husk 6 was put into a vinyl pipe having a diameter of 150 mm placed on a screen 14 made of the same perforated plate as in Example 1, and left for 3 minutes to drain the liquid. Further, an additional screen 16 made of another perforated plate (aperture rate 22.6%, round hole with a diameter of 1 mm, 60 degree staggered type) was installed, and two-stage filtration was performed.

  The height of the tea husk 6 on the upper screen (φ2) 14 after the end of the liquid draining was 53 mm (theoretical value 55 mm), and the recovery rate of the tea husk separation liquid 5 was 88.5%. Further, a thin layer of tea husk 6 was also deposited on the lower screen (φ1) 16, and the tea husk 6 could be separated with higher accuracy.

  Experiments were conducted in the same manner as in Example 1 except that the tea leaves were replaced with new tea (production area: 50% in Shizuoka Prefecture, 50% in Kagoshima Prefecture, variety: Yabukita).

  As a result, the height of the tea husk 6 on the screen 14 after the end of the liquid cutting was 90 mm (theoretical value 85 mm), and the recovery rate of the tea husk separation liquid 5 was 84%.

Comparative Example 3

  The experiment was performed in the same manner as in Example 4 except that the screen was changed to a 20 mesh general-purpose wire mesh.

  As a result, in Comparative Example 3, the height of the tea husk 6 on the screen was 115 mm, and the recovery rate of the tea husk separation liquid 5 was 72%. As a result, it was found that sufficient liquid was not discharged.

Schematic which shows the manufacturing apparatus of the tea-shell separation liquid which enforces the manufacturing method of the tea-shell separation liquid by this invention. The top view which shows a screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tea leaf 2 Water 3 Extract 5 Tea husk separation liquid 6 Tea husk 11 Extraction device 11a Stirrer 12 Steam jacket 13 Screen device 14 Screen 14a Hole 15 Receiving tank 16 Additional screen

Claims (5)

Supplying tea leaves together with water into the extraction device;
Mixing these tea leaves and water in an extraction device to produce an extract containing tea leaves;
Passing the extraction liquid in the extraction apparatus through a screen made of a perforated plate including a large number of holes to remove the tea leaves in the extraction liquid;
A process of receiving the extract through the screen and supplying it to the tank,
The perforated plate has a hole opening ratio of 20 to 50%, and each hole has an inner diameter of 1.5 mm to 2.5 mm. Supplying one or two kinds of tea leaves selected from fine tea leaves containing 50 to 100% by weight of a 20-mesh passing fraction, new green tea leaves, and high-quality gyokuro tea leaves together with water into the extraction device;
Mixing these tea leaves and water in an extraction device to produce an extract containing tea leaves;
Passing the extraction liquid in the extraction apparatus through a screen made of a perforated plate including a large number of holes to remove the tea leaves in the extraction liquid;
A process of receiving the extract through the screen and supplying it to the tank,
The perforated plate has a hole opening ratio of 20 to 50%, and each hole has an inner diameter of 1.5 mm to 2.5 mm.   3. The method for producing a tea leaves separation liquid according to claim 1, wherein each hole of the perforated plate is a round hole having an inner diameter of 2 mm.   After passing the extraction liquid in the extraction device through a screen made of a perforated plate, the extraction liquid was further passed through an additional screen to remove the tea shells in the extraction liquid and supply the extraction liquid to the tank. The method for producing a tea-shell separation liquid according to any one of claims 1 to 3.   5. The method for producing a tea leaves separation liquid according to claim 1, wherein the perforated plate is made of a metal plate including a large number of holes formed by punching.

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