JP2013230105A - Method of producing tea beverage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tea beverage suppressing tea dregs and precipitates and having high temporal stability while having natural turbidity and good aroma of quintessential tea, and a method of producing the same.SOLUTION: A method of producing a tea beverage includes: a step of extracting a tea extraction liquid from tea leaves; a step of filtering the tea extraction liquid to obtain an adjusted tea extract liquid; and a step of bringing the adjusted tea extract liquid into contact with an absorbent. A macropore volume (A) of the absorbent is not more than 1.0 cc/g, and the ratio [A/B] of the macropore volume (A) to a micropore volume (B) is 0.1-12.0.

Description

  The present invention relates to a tea beverage that has a natural turbidity and a good flavor, and that suppresses secondary orientation / precipitation and is highly stable over time, and a method for producing the tea beverage.

  Tea contains many useful ingredients including polyphenols, and is one of the beverages that are widely consumed all over the world. Thus, while tea is excellent in nutritional components, there is a problem in that orientation and precipitation occur when these components are combined. There are two types of “Ori”: primary and secondary. The primary orientation begins to precipitate immediately after the beverage is produced, and is called “tea cream” or “cream down”. This type of orientation is produced by combining liquid components such as caffeine and theaflavin, and can be prevented by performing a combination of centrifugation, enzyme treatment, membrane filtration, and the like. On the other hand, secondary ore is generated over time during storage after beverage production, but not all of the generation mechanism has been elucidated. Even if such a phenomenon does not affect the flavor of the tea beverage, it has a significant effect on the appearance of the tea beverage. In particular, when a tea beverage is filled in a transparent container, it may be judged that there is a problem in quality as well as reducing the consumer's willingness to purchase.

  Against this background, various researches have been made to solve the secondary orientation and precipitation problems that occur in tea beverages. Patent Document 1 uses a tea leaf having a specific component range to produce a beverage that does not easily cause orientation or browning even when stored. Patent Document 2 discloses that a tea extract is dispersed in a container solvent mixture, and then mixed with activated charcoal, acidic clay or activated clay, and a produced tea extract subjected to contact treatment with a synthetic adsorbent, thereby reducing the orientation and precipitation. Produces tea beverages that do not occur. Patent Document 3 obtains a tea extract that does not generate sediment even when stored for a long period of time by removing particles having a particle size of a certain size or more after concentrating the tea leaf extract. Although attempts have been made to produce tea beverages that do not generate oli and precipitation in this way, the processing process is complicated, and the ingredients that cause oli and precipitation are removed too much, and even the taste components are removed. There has been a problem that the appearance of the original natural turbidity of tea is lost. Therefore, there has been a demand for a tea beverage that has the original flavor and appearance of tea but does not cause orientation or precipitation.

JP 2011-155893 A JP 2007-167052 A JP 2009-066871 A

  The present invention has been made in view of the above problem, and has a natural turbidity and a good flavor inherent to tea, but has a stable and stable tea beverage in which the orientation and precipitation formed over time are suppressed. And it aims at providing the manufacturing method.

The present inventors have intensively studied to solve the above problems, and have completed the present invention. The present invention is as follows.
1. A step of obtaining a tea extract by extracting tea leaves, a step of filtering the tea extract to obtain a tea extraction adjustment liquid, and a step of bringing the tea extraction adjustment liquid into contact with an adsorbent, the macropores of the adsorbent Tea having a volume (A) of 1.0 cc / g or less and a ratio [A / B] of the macropore volume (A) to the micropore volume (B) of 0.1 to 12.0 A method for producing a beverage.
2. 2. The method for producing a tea beverage according to 1, wherein the tea extraction adjustment liquid is further adjusted to a suspended solid content / soluble solid content ([SS / Bx.]) = 15-100.
3. 3. The method for producing a tea beverage according to 1 or 2, wherein the tea extraction adjusting liquid is further adjusted to an electric conductivity of 0.5 to 3.0 [mu] S / cm.
4). The tea beverage according to any one of 1 to 3, wherein the ratio [C / B] of the mesopore volume (C) to the micropore volume (B) of the adsorbent is 0.1 to 20.0. Manufacturing method.
5. The method for producing a tea beverage according to any one of 1 to 4, wherein the tea extraction adjusting liquid and the adsorbent are brought into contact with each other for 1 to 80 seconds in the step of bringing the tea extraction adjusting liquid into contact with the adsorbent.
6). The method for producing a tea beverage according to any one of 1 to 5, wherein the adsorbent is activated carbon.

  The production method of the present invention enables a large amount of processing in a short time so as to be suitable for industrial production, and has a natural turbidity and a good flavor inherent to tea, while suppressing odor and precipitation and being stable over time. A highly functional tea beverage and a method for producing the tea beverage can be provided.

Hereinafter, embodiments of the present invention will be described.
The method for producing a tea beverage according to the present embodiment (hereinafter referred to as “the present production method”) is a method for producing a tea beverage having turbidity, and a step of extracting tea leaves to obtain a tea extract and The step of adjusting the suspended solid content / soluble solids ratio and / or electrical conductivity by filtering the tea extract accordingly, and the tea extraction adjustment solution has a specific macropore volume and is specific to micro And a step of contacting with an adsorbent having a pore volume ratio. In addition, unless it mentions specially except the said process, it is possible to employ | adopt the manufacturing process of a conventionally well-known tea drink suitably.
Further, in the present invention, “turbidity” means not transparent, and means a state where fine pieces derived from tea leaves are uniformly dispersed throughout the liquid, or are immediately dispersed by a slight vibration. The turbidity of the tea extract constitutes the flavor of tea, and when drinking, this turbid component is always contained in the drinker's mouth at a constant concentration, so a turbid tea beverage is a beverage with a good flavor . On the other hand, the term “ori / precipitation” means that tea components including insoluble components are combined and aggregated over time, forming large particles, which are unevenly distributed in the liquid, or deposited by sinking to the bottom of the container. It does not dissolve even with slight vibrations or several stirrings. From the above, “origin / precipitation” is clearly distinguished from “turbidity”.

(Raw tea leaves)
The raw material in this manufacturing method should just belong to tea tree (Camellia sinensis), and varieties such as tea leaves, growing place, growing conditions, plucking time, plucking conditions, etc. are not particularly limited (for example, “New Tea Industry Zensho” , See Shizuoka Prefectural Tea Chamber, first published in 1966). For example, tea varieties include Yabukita, Yutaka Midori, Sayaka Kaori, Kanaya Midori, Okumidori, Asatsuyu, Samidori, Benifuuki, Fujikaori, and Kaori. Moreover, the cultivation place of a tea leaf is not specifically limited as long as the tea leaf can be grown, and it may be in Japan or outside Japan. In Japan, for example, Shizuoka Prefecture, Kagoshima Prefecture, Mie Prefecture, Miyazaki Prefecture, Kyoto Prefecture and the like can be cited as specific production areas, but tea leaves obtained from tea trees grown outside Japan may also be used. Further, the picking time (tea period) is not particularly limited, and any one of the first tea, the second tea, and the autumn / winter tea can be used. There are no particular restrictions on tea leaf cultivation conditions, plucking conditions, etc., but, for example, tea made by a known method or an improved method based on this, or processed so that the content components of tea leaves are leached Can be adopted as appropriate. The same applies to oolong tea and black tea. For example, green tea (scented tea, gyokuro, stem tea, kabuse tea, strawberry tea, matcha tea, bancha, hojicha, kettle roasted tea, etc.) and jasmine tea, etc. It may be a non-fermented tea typified by fragrant), a semi-fermented tea typified by oolong tea, or a fermented tea typified by black tea.

(Extraction of tea leaves)
Extraction from tea leaves uses water as an extraction solvent. The water is preferably ion-exchanged water, and the extraction method may be any conventional method such as a kneader method, a basket method, a drip method, or a column method, preferably a kneader method. In consideration of the adsorbent treatment in the subsequent step, the extracted solid amount is 30% or more and 50% or less, preferably 30% or more and 40% or less of the tea leaf amount. Good. Therefore, it is effective to adjust the extraction temperature, the extraction time, the amount of extracted hot water, pH, and the like. On the other hand, it is not preferable to secure the eluted solid amount by an operation that excessively stirs during compression or extraction.
At the time of extraction, an organic acid salt such as sodium ascorbate or an organic acid may be added to water in advance. Moreover, you may use together the method of extracting in non-oxidative atmosphere which ventilates inert gas, such as boiling deaeration and nitrogen gas, and removes dissolved oxygen.

(Adjustment of tea extract)
Next, a step of filtering the tea extract to obtain a tea extraction adjustment solution is performed. In this process, in order to enable efficient adsorption of the substances causing sediment and precipitation in the subsequent contact treatment with the adsorbent, the tea extract is floated by an appropriate filtration process such as a shifter or centrifugal separation. The substance amount / soluble solid content amount and / or electric conductivity is adjusted to a state suitable for the subsequent contact step with the adsorbent. Each index will be described in detail below.

  The fine pieces derived from the raw tea leaves dispersed in the tea leaf extract form a sense of concentration, good mouthfeel and mellowness as “turbidity” in the tea beverage, and therefore it is preferable that an appropriate amount is present. However, when the amount is too large, “origin / precipitation” is likely to occur, and the adsorption efficiency in the subsequent adsorption treatment is lowered, which is not preferable. In particular, fine pieces derived from raw tea leaves need to be sorted according to their shape and specific gravity. Fine pieces with small shape and light specific gravity are dispersed in the beverage and the water-soluble components in the fine pieces are sufficiently eluted before the adsorption process, so the turbidity gives a sense of concentration, good mouthfeel and mellowness, etc. Contributes only to the taste. On the other hand, fine pieces with a large shape and heavy specific gravity have insufficient elution of the components in the fine pieces before the adsorption treatment, and there is no effect of adsorption. In addition, it becomes a major factor of secondary orientation. As a fine piece adjustment method, it is preferable to combine two filtration processes. As an example, there is a method of adjusting a fine piece having a large shape by filtering the tea extract with a 40-200 mesh net, and further adjusting a fine piece having a high specific gravity by centrifugation or the like, but the method is limited thereto. It is only necessary to adjust the shape and specific gravity of the fine pieces.

  The amount of suspended solids (SS) means fine pieces derived from tea leaves that do not dissolve in the water floating in the extract. In the present application, the suspended solid amount (SS) is used as an index for adjusting the liquid state before the adsorption treatment so that the adsorption treatment is properly performed, and the suspended solid amount contributes to taste and flavor as “turbidity”. Therefore, in the case of a palatable beverage, a certain amount of suspended solids is required. When the amount of suspended solids is adjusted to a range of 50 mg / L or less, preferably 10 to 45 mg / L, more preferably 15 to 40 mg / L, and most preferably 15 to 35 mg / L, The taste and flavor of the extract can also be maintained without reducing the efficiency of the liquid treatment. Moreover, as a component ratio in the amount of suspended solids, the dietary fiber content is preferably 40% or more, and the tannin containing catechin is preferably 10% or less. Adjustment is possible by combining selection of tea leaves, extraction conditions, and filtration conditions. Since the suspended solid amount (SS) is proportional to the reciprocal of the transparency, it can be calculated by measuring the transparency and then converting it to the suspended matter amount (SS). Here, tea beverages are converted into transparency based on red soil as described in pages 32 and 33 of the Okinawa Prefecture Agriculture, Forestry and Fisheries Department, “Agricultural and Rural Development Project, etc., Guide for Prevention of Outflow of Red Soil, etc. April 1997 (partially revised)” Was used to measure the suspended solid content (SS).

  The soluble solid content (Bx.) Is a unit for measuring the amount of gram of soluble solid contained in 100 g of a solution, and the refractometer indication for sugar at 20 ° C. measured using a commercially available refractometer. (Brix value). When the amount of the soluble solid content is too large, the adsorption reaction is hindered, and when it is too low, the adsorption reaction is good, but the obtained extract has a poor taste and flavor and is not preferable as a palatability beverage. In the present invention, it is possible to efficiently adsorb the causative substance of the secondary orientation component by adjusting to the range of 0.2 to 2.0. By setting it to preferably 0.3 to 2.0, more preferably 0.4 to 1.0, it is possible to obtain an aqueous liquid that maximizes adsorption efficiency and has good taste and flavor.

  Furthermore, in order to selectively adsorb water-soluble unnecessary components such as components causing sediment and precipitation, bitterness and miscellaneous components as adsorbents, the ratio of the amount of suspended solids to the amount of soluble solids is important. By adjusting the ratio of the amount of suspended solids to the amount of soluble solids [the amount of suspended solids (SS) / the amount of soluble solids (Bx.)] To 15-100, preferably 20-80, more preferably 25-60, This makes it possible to selectively adsorb unnecessary components such as a causative substance of a chemical orientation component.

  The electrical conductivity indicates the ease with which liquid can conduct electricity. Since electricity flows in the liquid due to the presence of the electrolyte in the liquid, the electrical conductivity increases as the amount of electrolyte in the water increases. Since charged ions are the current carriers, they can also be used as a guide for knowing the amount of electrolyte in the water. The electric conductivity can be measured with an electric conductivity meter, and the unit is represented by (μS / cm, micro Siemens / cm). In the adsorption process, the concentration of the ionic substance in the treatment liquid affects the adsorption efficiency. In the present invention, in the subsequent adsorption step, it is necessary to keep the electrical conductivity within a certain range in order to selectively remove the adsorbed substances from the water-soluble unnecessary components such as the ingredients causing sediment, bitterness and miscellaneous taste. There is. Therefore, the electrical conductivity is 0.5 to 3.0 μS / cm, preferably 1.1 to 2.0 μS / cm, and more preferably 1.2 to 1.6 μS / cm. Electrical conductivity is related to inorganic salts, but can be adjusted by selection and extraction of tea leaves, and can also be adjusted by appropriately adjusting the pH as a ionic substance concentration within a certain range.

  When the temperature of the extraction liquid is 55 ° C. or higher, the flavor is easily reduced. By adjusting the temperature within the range of 5 to 50 ° C., preferably 10 to 40 ° C., more preferably 15 to 30 ° C., the flavor of the extract can be maintained. When the extraction liquid is just after extraction, the liquid temperature is high. Therefore, the extraction liquid is adjusted to a predetermined temperature by placing it until it reaches a predetermined temperature or passing through a cooling device.

  When the pH is in the range of 3 to 8, preferably 4 to 7, and more preferably 4.5 to 6.5, stable adsorption treatment is possible. The pH is adjusted by adding an acid or an alkali agent. As the acid, salts of organic acids such as ascorbic acid and citric acid and / or inorganic acids and organic acids such as sodium ascorbate can be used. Examples of the alkali agent include hydroxides such as sodium hydroxide, potassium hydroxide and calcium hydroxide, carbonates such as sodium hydrogen carbonate and sodium carbonate, phosphates such as potassium phosphate and sodium phosphate, ammonium salts and the like. A substance having alkalinity can be used as an alkali agent. All are adjusted by appropriately adding one type or two or more types within the usage standards of food additives. Moreover, you may use the foodstuff material containing the said acid and an alkaline agent component.

(Step of bringing tea extraction adjustment liquid into contact with adsorbent)
The tea extraction adjustment liquid prepared under conditions suitable for the adsorption treatment is then subjected to a step of contacting with the adsorbent. The contact step includes a step of bringing the extraction adjustment liquid into contact with the adsorbent and separating the contacted extract from the activated carbon.
When the tea extraction adjustment liquid is passed, the present inventors have found that one of the useful ingredients of tea is a water-soluble unnecessary component such as an orientation / precipitation-causing component and a bitter / miscible component due to a difference in molecular weight. It has been found that it is adsorbed earlier in time than some polyphenols. The production method of the present invention utilizes this knowledge to make the water-soluble unnecessary component by using the difference between the time for the water-soluble unnecessary component to be adsorbed on the adsorbent and the time for the polyphenol to be adsorbed to the adsorbent. It is characterized by selective and efficient removal. Therefore, it is important in the present invention to appropriately adjust the pore size of the adsorbent and the contact time of the tea extraction adjusting liquid to the adsorbent.

  To perform the contact time of the tea extraction adjustment liquid to the adsorbent efficiently in a short time, and to adjust the contact time, the batch type or column type adsorption in which the adsorbent is added to the tea extraction adjustment liquid with stirring. Treatment or a combination of both is suitable. In view of workability, a column-type adsorption treatment is preferably employed in order to perform a short time adsorbent contact. The column system is a system in which an adsorbent is filled in a column having filters at the top and bottom, and the tea extraction adjustment liquid is continuously passed through the column from the lower part or the upper part and discharged to the other.

The liquid passing direction is preferably a direction in which the liquid is passed from the lower part to the upper part and discharged from the upper part. When the liquid is passed from above, the adsorbent accumulates and settles at the bottom of the column, and the activated carbon in the upper layer adsorbs water-soluble unnecessary components in advance, but the activated carbon in the lower layer cannot fully perform its function, This is because unevenness occurs. On the other hand, when the liquid is passed from the upper direction, the adsorbent floats in the column due to the upward water flow, the contact rate between the adsorbent and the tea extraction adjustment liquid increases, and all the adsorbent is not evenly water-soluble. It is possible to adsorb components and efficiently remove unnecessary water-soluble components. Preferably, the tea extraction adjustment liquid is adjusted from the lower part to the upper part of the column by adjusting the flow rate using blowing means such as a pump, and is passed through the adsorbent packed column.
The contact time between the tea extraction adjusting liquid and the adsorbent is adjusted to 1 to 80 seconds, preferably 2 to 60 seconds, and more preferably 3 to 30 seconds, regardless of the contact method. It is possible to efficiently adsorb the causative components of sediment and precipitation that occur secondarily while minimizing the amount.

  It is preferable to install a rectifying filter at the tea extraction adjusting liquid inlet of the column filled with the adsorbent. As a result, the tea extraction adjustment liquid is blown into the column like a shower, and the contact efficiency between the tea extraction adjustment liquid and the adsorbent is improved by dispersing the flow of the tea extraction adjustment liquid and floating the adsorbent particles. This is because it can be increased. The rectifying filter has a fine mesh shape or punched round hole shape covering the bottom of the column, has a space ratio of 30 to 60%, and an opening or diameter of 0.075 to 0.6 mm, preferably 0.1 to 0.00. 4 mm, more preferably 0.1 to 0.3 mm.

  A separation filter is installed at the tea extraction adjustment liquid outlet, which is the other end of the column, so that the adsorbent remains in the column and the tea extraction adjustment liquid after flowing through flows out. Thereby, an efficient separation process is possible. The separation filter is not particularly limited as long as it can stop the adsorbent to be used, such as a mesh or a punching metal. The opening diameter of the separation filter only needs to be smaller than the average particle diameter of the adsorbent, and preferably has an opening of 1/2 or less, particularly preferably 1/3 or less of the average particle diameter of the adsorbent. The specific opening diameter is preferably 0.1 to 1000 μm.

  The adsorption treatment temperature of the tea extraction adjustment liquid is 0 to 55 ° C., but preferably 5 to 50 ° C., more preferably 10 to 40 ° C., and most preferably 15 to 15 ° C. from the viewpoint of the flavor of the resulting tea extraction adjustment liquid. 30 ° C is good.

(Adsorbent used)
Adsorbents such as activated carbon generally have dendritic pores, relatively large pores (macropores) that form the trunk, and branched elongated pores (mesopores). And ultrafine pores (micropores) extending from the fine pores. Depending on the size of the micropores, those having a pore diameter exceeding 50 nm are called macropores, those having a pore diameter exceeding 2 nm and not more than 50 nm are called mesopores and those having a diameter of 2 nm or less are called micropores.
Adsorbents that can be used in the present invention are suitably those having pores such as micropores having a diameter of 2 nm or less, mesopores having a diameter of 2 to 50 nm, and macropores having a diameter of 50 nm or more. Activated carbon, silica gel, alumina, zeolite Resin etc. can be used. One or more of these adsorbents can be used in appropriate combination, but activated carbon is preferred. In the present invention, the adsorbent needs to have a special pore structure in order to selectively adsorb water-soluble unnecessary components such as sediment / precipitation-causing components and bitter / miscible components. In particular, it is important to adjust the volume ratio of the macro diameter serving as the filtrate passage and the micro diameter serving as the adsorption field to a constant ratio.

  The adsorbent used in the present invention is suitable to have a macropore volume (A) of 1.0 cc / g or less, preferably 0.1 to 0.8 cc / g, more preferably 0.8. 2 to 0.6 cc / g, most preferably 0.25 to 0.5 cc / g, and the ratio [A / B] of the macropore volume (A) to the micropore volume (B) is 0.1. ˜12.0, preferably 0.2 to 10.0, more preferably 0.3 to 5.0. The adsorbent having the ratio [A / B] of the macropore volume (A) to the macropore volume (A) and the micropore volume (B) within this range is a water-soluble component such as an ori / precipitation-causing component or a bitter / miscible component. This is because an unnecessary component is selectively adsorbed, and the adsorption rate increases in a preferable range.

Further, the ratio [C / B] of the mesopore volume (C) to the micropore volume (B) of the adsorbent is 0.1 to 20.0, preferably 0.1 to 10.0, more preferably 0.00. When it is 1 to 5.0, it is possible to efficiently remove water-soluble unnecessary components.
The micropore volume (B) is less than 1.0 cc / g, preferably 0.05 to 0.9 cc / g, more preferably 0.1 to 0.8 cc / g, most preferably 0.4 to 0.8 cc / g. and an adsorbent having a mesopore volume (C) of 0.05 to 0.6 cc / g, preferably 0.1 to 0.45 cc / g, more preferably 0.2 to 0.4 cc / g. Suitable for the invention. These holes can be measured by a known measurement method such as a gas adsorption method or a mercury intrusion method. Moreover, the ratio of these holes can be adjusted by performing a specific treatment. For example, activated carbon is produced from coconut husk, sawdust, coal, phenol resin, and the like, and has an activation process in which it is further reacted with water vapor at a high temperature after the carbonization process of steaming at a high temperature. By adjusting the activation conditions, the pore volume and ratio can be adjusted. In addition, in the case of silica gel, pore volume and ratio can be adjusted by impregnating ordinary spherical silica gel with phosphoric acid and performing heat treatment at high temperature. Furthermore, the optimal volume and ratio can be freely selected and used by combining two or more adsorbents whose pore volumes have been measured.

  The amount of the adsorbent used in the present invention is 0.01 to 1, preferably 0.05 to 0.5, more preferably 0.1 to 0.3, based on the weight of the tea leaf (adsorbent / tea leaf ratio). When the ratio is used, it is possible to efficiently adsorb unnecessary components.

  The adsorbent is preferably pretreated before use. By carrying out the pretreatment, the adsorption treatment can be carried out under optimum conditions. The pretreatment includes the following steps. First, the adsorbent is sufficiently swollen with water in advance to form a slurry before use. This is because air remains in the dry state and the adsorption efficiency is lowered. When the column is used, fine particles on the surface of the activated carbon can be washed and water remaining in the column can be removed by flowing water into the column after filling the column with an adsorbent.

  The tea beverage production method of the present invention is incorporated into the beverage production method as a whole or as a part, thereby suppressing orientation and precipitation and having a natural turbidity and good flavor inherent to tea while being stable over time. Tea drinks can be produced. The produced tea beverage selectively removes water-soluble unnecessary components without significantly reducing useful components such as polyphenols such as catechin and amino acids such as theanine and glutamic acid.

A general method for producing a beverage includes (1) extraction, (2) filtration, (3) preparation, and (4) filling step. The production method of the present invention can be partially or wholly incorporated during (1) extraction to (3) preparation. The method for producing a beverage of the present invention is not limited to the case where it is carried out for all the liquids, and the extract obtained by the production method of the present invention may be used as it is, diluted, or It is also possible to mix with the preparation liquid which is carried out with respect to the liquid of the part and does not carry out the present invention.
The tea beverage produced in the production method of the present invention can be further converted into a packaged beverage through necessary steps such as sterilization and filling into the container. As a container used in the container-packed drink manufactured by this embodiment, what is necessary is just a container for drinks normally used, and containers, such as metal cans and plastic bottles, such as a PET bottle, and a bottle are preferable.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  Hereinafter, the present invention will be described in more detail by showing test examples and the like, but the present invention is not limited to the following test examples and the like.

Method for Measuring Adsorbent Pore Volume The macropore volume (A) was determined from the volume of mercury injected by the mercury intrusion method (equipment used: CARLO ERBA INSTRUMENTS, Pascal 140 and 440). Micropore volume (B) and mesopore volume (C) were adsorbed using nitrogen gas in a gas adsorption method (use equipment: Quantachrome, quadruple specific surface area / pore distribution measuring device NOVA-4200e type) Obtained from the amount of gas.

Measuring method of water-soluble solid content (Bx.) It measured using the digital refractometer (The product made by Atago, RX-DD-7-Tea).

Measurement method for suspended solids (SS) After measuring the degree of transparency using a fluorometer (ST-30: 30 cm, manufactured by Shibata Kagaku Co., Ltd.), the Okinawa Prefectural Agriculture, Forestry and Fisheries Department “Agricultural and Rural Development Project, etc. The amount of suspended solids was calculated based on the conversion table described in pages 32 and 33 of the April 1997 (partially revised). The tea extract was adjusted to 20 ° C., then 300 mL was weighed in a 500 mL beaker, and the supernatant liquid allowed to stand for 1 hour was used for measurement.

Measurement method of electric conductivity The electric conductivity was measured using an electric conductivity meter (CM-40G, manufactured by Toa DK Corporation).

Method of measuring contact time between adsorbent and tea extract In the case of a batch type, the contact time between adsorbent and tea extract is measured from the time the adsorbent is added to the tea extract (conditioning liquid) until solid-liquid separation. In the case of the column system, the time until the tea extract (adjustment liquid) reaches the uppermost part from the bottom is the contact time, and the flow rate (L / sec) of the tea extract (adjustment liquid) to be sent It can be calculated from the volume (L) of the column filled with the adsorbent, and the contact time (second) = column capacity (L) / flow rate (L / second).

Sensory and visual evaluation method by panelists 10 trained panelists in charge of beverage development evaluate flavor and taste by tasting a sample of 100 mL, and visually observe the sample in a transparent PET 350 mL bottle container. evaluated. Although the conditions such as the temperature of the sample differ for each test example, the evaluation was made in five stages with respect to the three items of flavor, taste, and property according to the criteria shown below, and a four-stage comprehensive evaluation was performed based on the total score. The average value of evaluation is shown in each table.

= Evaluation of flavor =
5: Good 4: Slightly good 3: Normal 2: Not felt very much 1: Not felt at all

= Evaluation of taste =
5: Good 4: Slightly good 3: Normal 2: Not felt very much 1: Not felt at all

= Evaluation of properties =
5: No orientation / precipitation 4: Little orientation / precipitation 3: Little orientation / precipitation 2: Little orientation / precipitation 1: Many orientation / precipitation

= Comprehensive evaluation =
◎: Total score is 13 or more ○: Total score is 10 or more and less than 13 △: Total score is 6 or more and less than 10 ×: Total score is less than 6

<Test 1: Selection of adsorbent>
Example 1
(Preparation of extract)
60 g of Sri Lankan tea leaves were added to 1,800 g of ion exchange water at 70 ° C. in a stainless beaker and extracted for 10 minutes, then the tea leaves were removed from the extract by 80 mesh filtration, and then 6000 rpm × 5 minutes in a centrifuge. Treat to remove precipitate. Next, ion-exchanged water was added and diluted until the water-soluble solid content (Bx.) Reached 0.8.
(Treatment of equipment and adsorbent)
The column device was used to perform the adsorbent flow-through treatment. The tea extract is fed into the column from the bottom by a pump. A rectifying filter having an aperture of 0.18 mm and a space ratio of 31.4% is installed in the inflow portion. A filter having an eye of 0.18 mm is installed at the column outlet. Excess gas is exhausted through the vent. Activated carbon having pores described in Table 1 was immersed in ion-exchanged water, made into a slurry, and packed into a column.
(Adsorbent flow)
The column was adjusted to Bx. Using the adsorbent so that the ratio of the adsorbent / tea leaves was the value shown in Table 1 at room temperature. 0.8 tea extract was passed through. The contact time between the tea extract and the adsorbent was 10 seconds.
(Packing process)
The tea extract thus obtained was diluted with ion-exchanged water and Bx. Adjust the pH to 6.2 with sodium ascorbate at 0.25, heat sterilize at 135 ° C. for 30 seconds, and fill 353 mL into a 350 mL PET bottle container. Table 1 shows the evaluation results of the resulting beverage. Show.

Examples 2-10
The same procedure as in the example was performed except that the conditions described in Table 1 were employed.
The black teas used in this example are all Sri Lankan Uba, all green teas are Japanese Yabuki seeds, and all the oolong teas are Chinese daffodils. In this test example, the suspended solid amount (SS) of each sample was adjusted to 50 mg / L or less, and the suspended solid amount (SS) / soluble solid content (Bx) was adjusted to 15 to 100.
(Sensory evaluation time)
For Test Example 1, sensory and visual evaluation was performed by a paneler on the tea beverage after storage at 25 ° C. for 30 days.

<Test 2: Examination of tea extract conditions>
Examples 11-15
(Preparation of extract)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 2. FIG.
(Treatment of equipment and adsorbent)
The apparatus and adsorbent used in Example 1 were used.
(Adsorbent flow)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 2. FIG.
(Packing process)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 2. FIG.
(Sensory evaluation time)
Regarding Test Example 2, after storing for 14 days in a heat cycle test (5 ° C., 12 hours, 60 ° C., 12 hours cycle), sensory / visual evaluation was performed by a paneler at 25 ° C.

<Test 3: Examination of adsorption conditions>
Examples 16-20
(Preparation of extract)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 3. FIG.
(Treatment of equipment and adsorbent)
The apparatus and adsorbent used in Example 1 were used.
(Adsorbent flow)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 3. FIG.
(Packing process)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 3. FIG.
(Sensory evaluation time)
For Test Example 3, after storing at 60 ° C. for 14 days, sensory evaluation was performed at 60 ° C.

Example 21
(Preparation of extract)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 3. FIG.
(Adsorbent contact treatment)
Add an adsorbent to the tea extract so that the adsorbent ratio / tea leaf ratio is the same as in Example 1,
The mixture was constantly stirred at 20 rpm for the time as described, and filtered through a filter having 180 μm eyes.
(Packing process)
It carried out like Example 1 except having employ | adopted the conditions as described in Table 3. FIG.
(Sensory evaluation time)
For Test Example 3, after storing at 60 ° C. for 14 days, sensory evaluation was performed at 60 ° C.

As shown in Table 1, Examples 1 to 5 in which the ratio [A / B] of the macropore volume (A) to the macropore volume (A) and the micropore volume (B) is within a predetermined range are secondary. No sediment or precipitation was generated, and the sensory evaluation was also highly evaluated.
As shown in Table 2, Examples 11, 12 and 14 in which the relationship between the suspended solid content (SS) and the soluble solid content (Bx.) Is in the range of 20 to 60 are good despite the heat cycle test. Had a good flavor and taste. In particular, Examples 11 and 14 having a liquid temperature at the time of adsorption of 30 ° C. or less had almost no secondary orientation and were stable in properties.
As shown in Table 3, for the contact method between the adsorbent and the tea extract, in the case of the batch method, the precipitation is effectively suppressed, but the flavor / taste tends to be lost, so the column method is preferable. It was considered. Even in the column type, when the contact time is too short as 1 second or as long as 80 seconds or longer, the flavor and taste tend to be lost, while the contact time is 2 to 30 seconds in Examples 17 to No. 19 was excellent in the balance of taste, flavor and properties despite the high temperature acceleration test. In particular, in Examples 17 and 19, green tea beverages with good taste and flavor and good properties could be obtained.
If it is manufactured to satisfy the requirements of the present invention, it has a natural turbidity and good flavor inherent to tea, but does not cause secondary precipitation that occurs with time, and is stable over time. Obtained.

  The present invention enhances the efficiency of selectively removing water-soluble unnecessary components such as ingredients such as odor and precipitation, bitterness and miscellaneous taste, while having the natural turbidity and good flavor inherent in tea. The present invention provides a tea beverage having a high temporal stability and a method for producing the tea beverage. In addition, it is useful as a method for producing tea beverages in that a large amount of processing can be performed in a short time so as to be suitable for industrial production.

Claims (6)

Extracting tea leaves to obtain a tea extract;
A step of filtering the tea extract to obtain a tea extraction adjustment solution;
A step of bringing the tea extraction adjustment liquid into contact with the adsorbent,
The macropore volume (A) of the adsorbent is 1.0 cc / g or less, and the ratio [A / B] of the macropore volume (A) to the micropore volume (B) is 0.1 to 12.0. A method for producing a tea beverage characterized by the above.   The method for producing a tea beverage according to claim 1, wherein the tea extraction adjustment liquid is further adjusted to a suspended solid content / soluble solid content ([SS / Bx.]) = 15 to 100.   The method for producing a tea beverage according to claim 1 or 2, wherein the tea extraction adjustment liquid is further adjusted to an electric conductivity of 0.5 to 3.0 µS / cm.   The ratio [C / B] of the mesopore volume (C) to the micropore volume (B) of the adsorbent is 0.1 to 20.0, according to any one of claims 1 to 3. A method for producing tea beverages.   The method for producing a tea beverage according to any one of claims 1 to 4, wherein in the step of bringing the tea extraction adjustment liquid into contact with an adsorbent, the tea extraction adjustment liquid and the adsorbent are brought into contact with each other for 1 to 80 seconds. .   The method for producing a tea beverage according to any one of claims 1 to 5, wherein the adsorbent is activated carbon.