WO2015059808A1

WO2015059808A1 - Process for manufacturing tea drink

Info

Publication number: WO2015059808A1
Application number: PCT/JP2013/078915
Authority: WO
Inventors: 永田　幸三; 笹目　正巳; 賢二郎西原; 東洋忌部
Original assignee: 株式会社伊藤園
Priority date: 2013-10-25
Filing date: 2013-10-25
Publication date: 2015-04-30

Abstract

Provided are: a tea drink which has natural turbidity and good flavor that are inherent in tea and which suffers from few dregs or few precipitates and exhibits high stability even after the lapse of time; and a process for manufacturing the same. A process for manufacturing a tea drink, characterized by comprising a step for extracting tea leaves to prepare a tea extract, a step for filtering the tea extract to prepare a modified tea extract, and a step for bringing the modified tea extract into contact with an absorber which has a macropore volume (A) of 1.0cc/g or less and a ratio of macropore volume (A) to micropore volume (B) of 0.1 to 12.0.

Description

Method for producing tea beverage

The present invention relates to a tea beverage that has a natural turbidity and a good flavor, is suppressed in secondary orientation and precipitation, and has a high temporal stability, and a method for producing the tea beverage.

Tea contains many useful ingredients such as polyphenols and is one of the beverages that are widely used all over the world. Thus, while tea is excellent in nutritional components, there is a problem 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 oil is produced by combining components in the liquid such as caffeine and theaflavin, and can be removed by performing a combination of centrifugation, enzyme treatment, membrane filtration and the like. On the other hand, secondary orientation occurs 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, there is a possibility that it is judged that there is a problem in quality as well as a consumer's willingness to purchase.

From such a background, various researches have been made to solve the problem of secondary orientation and precipitation that occurs 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.

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

Thus, although attempts have been made to produce tea beverages that do not generate oli and precipitation, the processing process is complicated, and the components that cause oli and precipitation are removed, so that even the taste component is removed, or There was a problem that the appearance of the natural turbidity of the original tea was lost. Therefore, there is a demand for a tea beverage that has the original flavor and appearance of tea and does not cause orientation or precipitation.
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. According to the present invention, the following is provided.
1. A step of extracting tea leaves to obtain a tea extract, an adjustment step of filtering the tea extract to adjust the tea extract, and a step of bringing the tea extract after the adjustment step into contact with an adsorbent, A method for producing a tea beverage, wherein the macropore volume of the adsorbent is less than 1.0 cc / g, and the ratio of the macropore volume to the micropore volume is 0.1 to 12.0.
2. The method for producing a tea beverage according to 1 above, wherein the adjustment step further includes an additional adjustment in which the ratio of the suspended solid content to the soluble solid content in the tea extract is 15 to 100.
3. The method for producing a tea beverage according to 1 or 2 above, wherein the adjustment step further includes an additional adjustment in which the electric conductivity of the tea extract is adjusted to 0.5 to 3.0 μS / cm.
4). 4. The method for producing a tea beverage according to any one of 1 to 3 above, wherein the ratio [C / B] of the mesopore volume (C) to the micropore volume (B) of the adsorbent is 0.1 to 20.0.
5. The method for producing a tea beverage according to any one of 1 to 4 above, wherein, in the step of bringing the tea extract after the adjusting step into contact with an adsorbent, the tea extract is brought into contact with the adsorbent for 1 to 80 seconds.
6). 6. The method for producing a tea beverage according to any one of 1 to 5 above, wherein the adsorbent is activated carbon.
7). A tea beverage comprising a step of extracting tea leaves to obtain a tea extract, and an adsorption step of selectively adsorbing a component having a molecular weight of about 1000 or less by contacting the tea extract with a porous adsorbent having micropores Manufacturing method.
8). Furthermore, it has the adjustment process which adjusts the tea extract before the said adsorption process in the state suitable for selective adsorption | suction, The said adjustment process is a manufacturing method of said 7 tea drinks including filtration separation and centrifugation.
9. The adjustment step has an additional adjustment to adjust the suspended solid amount, soluble solid content, electrical conductivity and pH of the tea extract before the adsorption step, and the additional adjustment includes dilution with water 8 Method for producing tea drinks.

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.

In order to obtain a tea beverage that has the original flavor and appearance of tea but does not cause oliage or precipitation, components that cause oliability and precipitation without removing the taste components from the turbid components of the tea extract Need to be removed. The components that become the primary orientation are relatively large and heavy particles, which can be easily separated and removed by, for example, filtration. On the other hand, the component that is the source of secondary orientation that occurs with time is relatively small and light particles, and in order to remove this, only a turbid component in a suitable range as a taste component is a tea extract. It is necessary to remove small and light particles from the tea extract so that they remain, but this is extremely difficult. The present invention has been found based on this finding that it has been found that the removal of components that are the source of secondary orientation can be carried out by an adsorption treatment using a specific adsorbent.

In the above-mentioned adsorption treatment, the use of a porous adsorbent with micropores is effective, and by selectively adjusting adsorption conditions, the components that cause sediment and bitterness and bitterness are selectively adsorbed and removed. The taste component can be suitably left in the liquid with high separation efficiency. In the adsorption process, the contact between the tea extract and the adsorbent is efficiently performed and controlled appropriately. Therefore, as a physical requirement, first, the contact is inhibited. Easy to remove coarse particles and heavy particles, the amount of suspended solids in the tea extract must be in the proper range, and secondly, the tea extract has a moderate fluidity that makes it easy to control the contact with the adsorbent As shown, the soluble solid content needs to be in an appropriate range. Furthermore, since the adsorptive capacity of the adsorbent is affected by the concentration of ionic substances in the tea extract, the electrical conductivity of the tea extract is a physicochemical requirement that the adsorbent can suitably exhibit the selective adsorbing capacity. And the pH needs to be in the proper range.

With regard to the first physical requirement described above, the tea extract can be adjusted by a separation process such as filtration separation, solid-liquid separation, etc., and a filter medium so as to filter and separate particles having a size and density greater than or equal to a predetermined value. By setting the eye dimensions and solid-liquid separation conditions, coarse particles and heavy particles can be removed from the tea extract, and the amount of suspended solids can be adjusted to an appropriate range. By such a separation process, removal of a component that becomes a primary orientation is also achieved at the same time. With respect to the second physical requirement, the amount of soluble solids can be adjusted by adjusting the concentration, that is, by dilution or concentration, and is achieved by appropriately performing the above-described tea extract after the separation treatment. The concentration adjustment is also a means for adjusting the amount of suspended solids described above. Regarding the physicochemical requirements, the electrical conductivity and pH of the tea extract depend on the extraction composition, that is, it varies depending on the quality of the raw tea leaves to be extracted and the extraction conditions (temperature and time, etc.). It depends on tea type, variety, cultivation conditions, plucking time, tea making / processing conditions, etc. Therefore, it is achieved by performing extraction under extraction conditions that easily approach appropriate electrical conductivity and pH according to the quality of the raw tea leaves used, and additionally adjusting after the above-described separation treatment as necessary. Additional adjustment includes dilution with water and addition of components such as organic acids, and dilution is also a means for adjusting the amount of suspended solids and soluble solids described above.

As described above, there are not a few condition items necessary for the tea extract to be subjected to the adsorption treatment, but a plurality of condition items can be adjusted by a single means. By diluting and / or adding components, the amount of suspended solids, soluble solids and electrical conductivity of the tea extract can be adjusted to appropriate ranges, that is, adjusted to conditions suitable for adsorption treatment. it can.

Hereinafter, embodiments of the present invention will be described.
The method for producing a tea beverage (hereinafter referred to as “the present production method”) is a method for producing a turbid tea beverage, in which a tea leaf is extracted to obtain a tea extract, and a micropore is formed in the tea extract. An adsorption step of selectively adsorbing a component having a molecular weight of about 1000 or less by bringing the porous adsorbent into contact with the porous adsorbent. An adjustment process for adjusting the tea extract before the adsorption process is performed. In the adjustment process, the tea extract is filtered and separated under specific conditions to remove coarse and heavy particles, and the total amount of suspended solids is adjusted. By adjusting, the suspended solid amount (concentration), soluble solid content (concentration) and electrical conductivity are adjusted. In the adsorption step, the adjusted tea extract is contacted with an adsorbent having a specific macropore volume and a specific mesopore to micropore volume ratio. In addition, although not specifically mentioned here, as long as the tea extract does not substantially deviate from the present invention, in addition to the above-described steps, it is possible to appropriately employ the steps performed in the manufacture of conventionally known tea beverages.
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 mouth of the drinker at a constant concentration. Become. On the other hand, the term “ori / precipitation” means that tea components including insoluble components are combined or aggregated (over time) to form relatively large particles, which are unevenly present in the liquid, or sink to the bottom of the container. It is deposited in a manner that does not become uniform due to slight vibration or several stirrings. According to the above, “origin / precipitation” is clearly distinguished from “turbidity”.

(Raw tea leaves)
The raw material in this production method only needs to belong to tea tree (Camellia sinensis), and varieties such as tea leaves, rearing place, rearing conditions, picking time, picking conditions, etc. are not particularly limited (for example, “New Tea Industry Zensho”) , See Shizuoka Prefectural Tea Chamber, first published in 1966). Examples of 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 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 plants grown outside Japan may 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, and the like, for example, tea made by a known method or a method improved based on this, or processed so that the content components of tea leaves are leached. A thing can be employ | adopted suitably. The same applies to oolong tea and black tea. Therefore, green tea (sencha, gyokuro, stem tea, kabuse tea, strawberry tea, matcha tea, bancha, roasted tea, 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, but the kneader method is preferably used. In consideration of the adsorption treatment in the subsequent process, extraction is performed so that the amount of solid eluted by extraction is 30% to 50%, preferably 30% to 40% with respect to the amount of tea leaves. Is good. For this purpose, it is effective to adjust the extraction temperature, extraction time, amount of extracted water, pH, and the like. It should be noted that it is not preferable to secure the eluted solid amount by an operation such as pressing or excessive stirring during extraction.
In the extraction, in order to adjust the adsorption efficiency, water in which an organic acid salt such as sodium ascorbate or an organic acid is added in advance may be used. Since this changes the electrical conductivity and pH of the tea extract, it is better to consider the adjustment conditions described later. 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, an adjustment process is performed in which the tea extract is filtered and separated to obtain a tea extract adjusted to a state suitable for the adsorption treatment. In this process, appropriate filtration / separation using a shifter, centrifuge, etc. to enable efficient selective adsorption of substances that cause sediment and precipitation in subsequent contact with the adsorbent (adsorption treatment). Is applied to the tea extract. This process will be specifically described below.

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 tea beverages, so it is preferable to be present in an appropriate amount, but it is excessive In this case, not only “origin / precipitation” is likely to occur, but also 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 by their shape and specific gravity. Of the fine pieces, small pieces with small specific gravity are easy to disperse in beverages, and the water-soluble components in the fine pieces are sufficiently eluted in a short period of time to stabilize before the adsorption treatment and become turbid and have a concentration sensation.・ Contributes only to taste such as good taste and mellowness. On the other hand, when the specific gravity is large, the elution of the components in the fine pieces is insufficient and proceeds during the subsequent adsorption treatment, so that the effectiveness of the adsorption treatment is impaired, and the elution of the water-soluble components over time. Affects flavor and is a major factor in secondary orientation. As a method of adjusting such fine pieces to a suitable state, it is preferable to combine two separation processes. Specifically, the tea extract is filtered through a 40-200 mesh net (filter separation) to remove large fine pieces, and further, centrifugal separation or the like (sediment separation) is used to precipitate fine pieces with a large specific gravity. The method of adjusting the size and specific gravity of the fine pieces in the tea extract to a suitable range by separating and removing can be mentioned, but the method is not limited to these, and the size and specific gravity of the fine pieces can be adjusted. That's fine.

The adjustment process may include additional adjustment to the tea extract that has been subjected to the filtration and separation as described above. In the additional adjustment, dilution with water and addition of components such as organic acid are performed. As a result, the concentration and composition of the tea extract change, dilution is the aforementioned means for adjusting the amount of suspended solids and soluble solids, and addition of components such as organic acids is means for adjusting the electrical conductivity and pH. . In addition of components, an acid or an alkaline agent is used to adjust the pH. As the acid, organic acids such as ascorbic acid and citric acid and / or inorganic acids, and salts of organic acids such as sodium ascorbate can be used. is there. Examples of the alkaline agent include hydroxides such as sodium hydroxide, potassium hydroxide and calcium hydroxide, carbonates such as sodium bicarbonate and sodium carbonate, phosphates such as potassium phosphate and sodium phosphate, ammonium salts and the like. A substance having alkalinity can be used. All are within the usage standards for food additives, and one or more can be used in appropriate combination. Moreover, you may use the foodstuff material containing the said acid or alkali agent component.
Thereby, a tea extraction liquid turns into an adjustment liquid adjusted to the state suitable for contact with the adsorbent in a subsequent adsorption process. As an index for confirming this state, there are the amount of suspended solids contained in the liquid, the amount of soluble solids, the electrical conductivity and the pH. By examining these, the state of the adjustment liquid can be known. Hereinafter, each index will be described in detail.

Suspended substance amount (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 process so that the adsorption process is appropriately performed. At the same time, the suspended matter contributes to taste and flavor as “turbidity”, so that a certain amount of suspended matter needs to be present in the palatable beverage. Therefore, the suspended solid amount is adjusted to be 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. By the above filtration and centrifugation, excessive particles and particles that easily settle are removed, and the amount of suspended solids can be adjusted to the above range. Thereby, suitable selective adsorption | suction can be performed without reducing the liquid passing efficiency (contact efficiency) in subsequent adsorption | suction processing, and the taste and flavor of an extract can be maintained. Since the suspended solid amount (SS) is proportional to the reciprocal of the transparency, it can be determined by measuring the transparency and converting it to the suspended matter amount (SS). Here, based on the peculiar colors of tea beverages, the degree of transparency of red soil described on pages 32 and 33 of the Okinawa Prefectural Agriculture, Forestry and Fisheries Department “Agricultural and Rural Development Project, etc. Guide for Prevention of Runoff of Red Soil” Suspended matter amount (SS) is measured using conversion. Moreover, as a component ratio in a suspended solid, dietary fiber content is preferably 40% or more, and tannin containing catechin is preferably 10% or less. These component ratios can be adjusted by combining tea leaf selection, extraction conditions, and filtration conditions.

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. Therefore, in the present invention, the soluble solid content is preferably in the range of 0.2 to 2.0, and in this range, the secondary causative component can be efficiently adsorbed. 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. Since the soluble solid content can be optimized by adjusting the concentration, when the soluble solid content is excessive after the filtration and centrifugation described above, it may be diluted with water.

It should be noted that the ratio of the amount of suspended solids to the amount of soluble solids is important in selectively adsorbing water-soluble unnecessary components such as ingredients that cause sediment and bitterness and miscellaneous taste as adsorbents. 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. The selective adsorption of unnecessary components such as the causative component of the secondary orientation can be suitably performed.

¡Electric conductivity indicates the ease of liquid electricity. The charged ions are the current carriers, and electricity flows through the liquid due to the presence of the electrolyte in the liquid. Therefore, the greater the amount of electrolyte in the water, the higher the electrical conductivity. That is, the electrical conductivity is also a measure 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 treatment, the concentration of the ionic substance in the treatment liquid affects the adsorption efficiency. Therefore, in the present invention, in the subsequent adsorption step, water-soluble unnecessary components such as an origin / precipitation-causing component and a bitter / miscible component are covered. In order to selectively remove as an adsorbing substance, the electric conductivity needs to be within a certain range. Specifically, 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. The electrical conductivity is related to the content of inorganic salts, but can be adjusted by selection of tea leaves and extraction conditions. Further, the electric conductivity can be adjusted by adjusting the pH within a certain range as the ionic substance concentration.

When the pH is in the range of 3 to 8, preferably 4 to 7, more preferably 4.5 to 6.5, stable adsorption treatment can be performed. For adjusting the pH, the aforementioned acid or alkali agent is used.

The tea extract immediately after extraction has a high temperature, but if the temperature of the extract is 55 ° C. or higher, the flavor tends to be reduced, so 5 to 50 ° C., preferably 10 to 40 ° C. More preferably, the flavor of the extract can be maintained by adjusting and maintaining the temperature within the range of 15 to 30 ° C. Therefore, the tea extract immediately after extraction is allowed to stand until reaching a predetermined temperature before reaching the adsorption process, or it is adjusted to the above temperature range by passing through a cooling device, and the time at a high temperature is as long as possible. It is desirable to shorten it.

(Adsorption process in which the adjusted tea extract is brought into contact with the adsorbent)
The tea extract adjusted to conditions suitable for the adsorption treatment is introduced into the adsorption process. In this step, the adjusted tea extraction adjustment is brought into contact with the adsorbent for a predetermined time, and the extracted liquid after contact is separated from the adsorbent.
When the tea extract is brought into contact with the adsorbent, water-soluble unnecessary components such as ingredients that cause sediment and bitterness and miscellaneous components are caused by polyphenols and other teas due to differences in molecular weight. It was found that it was adsorbed earlier in time than useful components. In other words, by selectively using the difference between the time during which water-soluble unnecessary components are adsorbed on the adsorbent and the time during which polyphenols are adsorbed on the adsorbent, the water-soluble unnecessary components are selectively removed efficiently. Can do. In this selective adsorption, it is important to appropriately adjust the pore size of the adsorbent and the contact time of the tea extraction adjusting liquid to the adsorbent.

In order to suitably perform the contact between the adjusted tea extract and the adsorbent and appropriately adjust the contact time, a batch-type treatment in which the adsorbent is added to the tea extract with stirring, or A column-type process in which a tea extract is passed through a column containing an adsorbent, or a combination of both is suitable. In view of workability, column-type adsorption treatment is preferably employed in order to enable contact in a short time. In the column method, the adsorbent is accommodated in a vertical column having filters at the upper end and the lower end, and the tea extract is continuously supplied to the column from the lower end or the upper end to pass through the column. It is a method of discharging from the end.

With respect to liquid flow in the column system, in the present invention, a liquid flow system in which liquid is passed from the lower end of the column toward the upper end and discharged from the upper end is preferable. When the liquid is passed from the upper end to the lower end, the adsorbent accumulates and settles at the bottom of the column and the upper layer adsorbent adsorbs water-soluble unnecessary components in advance, but the lower layer adsorbent has sufficient function. In the adsorbent, resulting in uneven processing. Compared to this, when the liquid is passed from the lower end to the upper end, the adsorbent floats in the column due to the upward flow of tea extract, and the adsorbent can flow and circulate. Contact with the tea extract is equalized, and all adsorbents adsorb water-soluble unnecessary components evenly, making it possible to efficiently remove water-soluble unnecessary components. If the tea extract is supplied to the column using a blowing means such as a pump, and the flow rate is adjusted by the drive control of the pump, the contact time can be easily adjusted, and it is preferably passed through the adsorbent column. Therefore, it is preferable.
The contact time between the tea extraction adjusting solution and the adsorbent is adjusted to 1 to 80 seconds, preferably 2 to 60 seconds, and more preferably about 3 to 30 seconds, regardless of the contact method. As a result, components having a molecular weight of about 1000 or less are adsorbed, so that the causative components of secondary occurrence and precipitation are efficiently adsorbed while minimizing the reduction in flavor and taste in the tea extract. be able to.

It is preferable to install a rectifying filter at the inlet (preferably the lower end of the column) of the tea extract of the column containing the adsorbent so that the tea extract is blown into the column in a shower form. Thereby, the flow of the tea extract is parallel to the layer, and the adsorbent particles float and fall, and the contact between the tea extract and the adsorbent can be made uniform by circulation and replacement of the adsorbent. The rectifying filter is a member having a fine mesh shape covering the column inlet or a multi-hole plate (round hole) shape such as punching metal. The opening ratio is 30 to 60%, and the aperture or the hole diameter is 0.075 to 0.00. It is 6 mm, preferably 0.1 to 0.4 mm, more preferably 0.1 to 0.3 mm.

At the other end of the column (that is, the tea extract outlet), a separation filter is installed so that the adsorbent is held in the column and only the tea extract after coming into contact with the adsorbent flows out. To do. As a result, the tea extract is separated from the adsorbent and contact is limited, so that separation by selective adsorption becomes 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. A specific opening diameter is preferably 0.1 to 1000 μm.

The tea extract can be adsorbed at a temperature of 0 to 55 ° C., but preferably 5 to 50 ° C., more preferably 10 to 40 ° C., most preferably from the viewpoint of the flavor of the resulting tea extraction adjustment solution. Is preferably 15 to 30 ° C.

(Adsorbent used)
Porous adsorbents with micropores such as activated carbon generally have dendritic pores, relatively large pores (macropores) constituting the trunk, and then branching It is composed of elongated micropores (mesopores) and ultrafine pores (micropores) extending from the micropores. Depending on the size of the pores, those having a pore diameter exceeding 50 nm are called macropores, those having more than 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 those having micropores with a diameter of 2 nm or less, mesopores with a diameter of 2 to 50 nm, and macropores with a diameter of 50 nm or more, such as activated carbon, silica gel, alumina, zeolite, and resin. It can be used. One or a plurality of these adsorbents can be used in appropriate combination, but activated carbon is preferably used from the viewpoint of affinity with the adsorbent. 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 that the volume ratio of the macropores serving as the filtrate passage to the micropores serving as the selective adsorption field is a suitable ratio.

As the adsorbent used in the present invention, an adsorbent having a macropore volume (A) of less than 1.0 cc / g is suitable, preferably 0.1 to 0.8 cc / g, more preferably 0. 0.2 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 to 12.0, preferably 0.2-10.0, more preferably 0.3-5.0 is used. The adsorbent in which the ratio [A / B] of the macropore volume (A) and the macropore volume (A) to the micropore volume (B) is in the above-mentioned range is a component that causes sediment, bitterness, and miscibility. It is easy to adsorb water-soluble unnecessary components such as (that is, adsorb quickly), and selectively adsorbs by limiting the contact time. As the pore volume is in a preferable range, such adsorption ability increases and selectivity is improved. However, this selective adsorption is a sensitive action due to the physicochemical balance and is easily affected by surrounding factors. Therefore, the micropores are effective when the tea extract is adjusted and the adsorption conditions are appropriate. And manifest.

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.
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 invention. These pore volumes can be measured by a known measurement method such as a gas adsorption method or a mercury intrusion method. Further, the ratio of these pores can be adjusted by performing a specific treatment. For example, activated carbon is produced from coconut husk, sawdust, coal, phenol resin, etc., and obtained by subjecting it to an activation step that reacts with water vapor at a high temperature after the carbonization step of steaming at a high temperature. By adjusting the pore volume, the pore volume and the pore ratio can be adjusted. For example, the technology described in JP-T-2012-520230 can be referred to. 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 pore volume and pore ratio can be arbitrarily adjusted by combining two or more kinds of adsorbents in which micropores to macropores whose pore volumes are measured are mixed. Adsorbents with pore volume and pore ratio can be used freely.

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 mass, 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. That is, there is a correspondence relationship with the amount of extracted component (the amount of component in contact with the adsorbent) obtained corresponding to the tea leaf weight.

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 preliminarily wetted with water to form a slurry. This is because in the dried state, air remains inside and the adsorption efficiency is lowered. Thereafter, the adsorbent is put into the column, and water is supplied into the column and water is passed therethrough. Thereby, the fine powder etc. on the surface of the adsorbent can be washed, and the air remaining in the column can be removed.

General beverage production methods include (1) extraction, (2) filtration, (3) preparation, and (4) container filling. The tea beverage production method of the present invention can be used as a built-in element constituting the whole or part of the beverage production process. Specifically, a part from (1) extraction to (3) preparation described above. Or, as a whole, the production method of the present invention can be incorporated. As a result, it is possible to produce a tea beverage having a natural turbidity and a good flavor inherent to tea, while suppressing orientation and precipitation and high stability over time. The produced tea beverage preferably contains useful components such as polyphenols such as catechin, amino acids such as theanine and glutamic acid, and water-soluble unnecessary components are selectively removed.

The manufacturing method of the drink of this invention is not limited to the form implemented with respect to all the tea extracts. That is, in the production method of the present invention, the tea extract obtained by extraction may be used as it is, or it may be applied to a part of the liquid and blended with a tea extract that does not carry out the present invention. Is possible. Moreover, you may use for the manufacturing method of this invention the tea extract diluted after obtaining by extraction.
The tea beverage produced by 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. The container used for the beverage container produced according to the present invention may be a commonly used beverage container, and is preferably a metal can, a plastic bottle such as a PET bottle, or a container such as a bottle.

As described above, the embodiments described in the present application are described for facilitating understanding of the present invention, and are 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.

<Measurement method of pore volume of adsorbent>
Macropore volume (A) was calculated | required from the volume of the inject | poured mercury according to the mercury intrusion method (The apparatus used: Carlo ERBA INSTRUMENTS company make, Pascal 140 and 440). The micropore volume (B) and the mesopore volume (C) were measured using nitrogen gas according to the gas adsorption method (equipment used: Quantachrome, quadruple specific surface area / pore distribution measuring device NOVA-4200e type). It was determined from the amount of adsorbed gas.

<Method for measuring water-soluble solid content (Bx.)>
Measurement was performed using a digital refractometer (RX-DD-7-Tea, manufactured by Atago Co., Ltd.).

<Measurement method of suspended solid content (SS)>
After measuring the degree of fluoroscopy using a fluorometer (made by Shibata Kagaku Co., ST-30: 30cm), Okinawa Prefecture Agriculture, Forestry and Fisheries Department, “Agricultural and Rural Development Project, etc. Guide for Prevention of Outflow of Red Soil, etc. April 1997 The amount of suspended solids was calculated based on the conversion table described on pages 32 and 33 of “Revision”). Moreover, after adjusting tea extract to 20 degreeC, 300 mL was measured to a 500 mL beaker, and the supernatant liquid which left still for 1 hour was used for the measurement.

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

<Measurement method of contact time between adsorbent and tea extract>
In the case of a batch system, the contact time with the adsorbent is the time from the addition of the adsorbent to the tea extract (conditioning liquid) until solid-liquid separation. In the case of the column method, the contact time is the time from when the tea extract (conditioning solution) reaches the top (discharge port) from the bottom (inlet) of the column containing the adsorbent. It can be calculated from the flow rate (L / sec) of the tea extract (conditioning solution) to be supplied and the volume (L) of the column containing the adsorbent, and the contact time (sec) = column capacity (L) / flow rate (L / Second).

<Sensory and visual evaluation methods by panelists>
A panel of 10 trained persons in charge of beverage development evaluated the flavor and taste by tasting a 100 mL sample, and evaluated the properties by visually observing the sample in a 350 mL transparent PET bottle container. . Although conditions such as the temperature of the sample differ for each test example, the three items of flavor, taste, and property are evaluated in five stages according to the following criteria, and the comprehensive evaluation is based on the comprehensive points of the evaluation of the above three items. It was evaluated in four stages. The average value of the evaluation of 10 panelists in each item 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>
[Sample 1]
(Preparation and adjustment of tea extract)
60 g of black tea leaves from Sri Lanka were extracted for 10 minutes in addition to 1,800 g of ion exchange water at 70 ° C. put in a stainless beaker. Next, the tea leaves were removed from the tea extract by filtration through an 80-mesh net, and then treated with a centrifuge at 6000 rpm for 5 minutes to remove precipitates from the tea extract. Furthermore, ion-exchanged water was added and diluted so that the water-soluble solid content (Bx.) Was 0.8, whereby a tea extract of Sample 1 was obtained.

(Adsorption device and adsorbent)
Adsorption treatment by contact with the adsorbent described below was performed using a column apparatus. A rectifying filter having an aperture of 0.18 mm and an aperture ratio of 31.4% was installed at the inflow portion of the column. A filter having an eye of 0.18 mm was installed at the outlet of the column. The adsorbent (activated carbon) having pores described in Table 1 was dipped in ion exchange water and wetted to form a slurry. This adsorbent was loaded into the column according to the following description. Excess gas was exhausted through the vent. In the column apparatus, the tea extract was supplied from the lower end to the column by a pump and subjected to the following adsorption treatment.

(Adsorption treatment)
The adsorbent was put into the column so that the adsorbent / tea leaf ratio was the value shown in Table 1, and Bx. An adsorption treatment was performed by passing 0.8 tea extract (sample 1) through the column at room temperature and bringing it into contact with the adsorbent. The contact time between the tea extract and the adsorbent was 10 seconds.
(Packing process)
The tea extract discharged from the column was diluted with ion-exchanged water, and Bx. Is adjusted to 0.25, pH is adjusted to 6.2 using sodium ascorbate, sterilized by heating at 135 ° C. for 30 seconds, 353 mL of which is filled into a 350 mL PET bottle container. Used for beverage evaluation. Table 1 shows the beverage evaluation results.

[Samples 2 to 10]
Except that the conditions described in Table 1 were adopted, the tea extract was prepared, adjusted, adsorbed and packed in the same manner as Sample 1. The black teas used were all Sri Lankan Uba, the green teas were all Japanese Yabuki seeds, and the oolong teas were all Chinese narcissus seeds. As the adsorbent, activated carbon, silica gel, alumina or zeolite having a porous structure shown in Table 1 was used. In the adjusted tea extracts of samples 2 to 10, the suspended solid amount (SS) is 50 mg / L or less, and the suspended solid amount (SS) / soluble solid content (Bx) ratio is 15 to 100. Adjusted.
(Sensory evaluation time)
After the tea drinks of Samples 1 to 10 were stored at 25 ° C. for 30 days, sensory and visual evaluations were performed using a panel.

<Test 2: Examination of tea extract conditions>
[Samples 11 to 15]
(Preparation and adjustment of tea extract)
A tea extract was prepared and adjusted in the same manner as Sample 1 except that the conditions described in Table 2 were adopted.

(Adsorption device and adsorbent)
The adsorption device and adsorbent used in Test 1 were used.
(Adsorption treatment)
The adsorption treatment was performed in the same manner as Sample 1 except that the conditions described in Table 2 were adopted.
(Packing process)
Container filling was performed in the same manner as Sample 1 except that the conditions described in Table 2 were adopted.
(Sensory evaluation time)
For samples 11 to 15, the container-packed beverage was subjected to a heat cycle test (5 ° C .: 12 hours, 60 ° C .: repeated heating / cooling cycle of 12 hours) for 14 days, and then sensory and visual by a panel at 25 ° C. Evaluation was performed.

<Test 3: Examination of adsorption conditions>
[Samples 16 to 20]
(Preparation and adjustment of tea extract)
A tea extract was prepared and adjusted in the same manner as Sample 1 except that the conditions described in Table 3 were employed.
(Adsorption device and adsorbent)
The adsorption device and adsorbent used in Test 1 were used.
(Adsorption treatment)
The adsorption treatment was performed in the same manner as Sample 1 except that the conditions described in Table 3 were employed.

(Packing process)
Container filling was performed in the same manner as Sample 1 except that the conditions described in Table 3 were adopted.
(Sensory evaluation time)
For Samples 16 to 20, the packaged beverage was stored at 60 ° C. for 14 days, and then sensory evaluation was performed at 60 ° C.

[Sample 21]
(Preparation and adjustment of tea extract)
A tea extract was prepared and adjusted in the same manner as Sample 1 except that the conditions described in Table 3 were employed.
(Adsorption treatment)
The adsorbents having pores listed in Table 3 were dipped in ion exchange water and wetted to form a slurry. This adsorbent is added to the adjusted tea extract so that the adsorbent / tea leaf ratio is the same as that of sample 1, and stirring at 20 rpm is performed for the contact time shown in Table 3 to obtain a filter having 180 μm eyes And filtered.

(Packing process)
Container filling was performed in the same manner as Sample 1 except that the conditions described in Table 3 were adopted.
(Sensory evaluation time)
Regarding sample 21, the container-packed beverage was stored at 60 ° C. for 14 days, and then sensory evaluation was performed at 60 ° C.

As shown in Table 1, in Samples 1 to 5 in which the ratio [A / B] of the macropore volume (A) and the macropore volume (A) to the micropore volume (B) is within a predetermined range, The next occurrence of sediment and precipitation is not observed, and the sensory evaluation is also highly evaluated.

As shown in Table 2, in the samples 11, 12, and 14 in which the ratio of the suspended solid content (SS) to the soluble solid content (Bx.) Is in the range of 20 to 60, despite the heat cycle test, It has a good flavor and taste. In particular, Samples 11 and 14 having a liquid temperature at the time of adsorption of 30 ° C. or less showed little occurrence of secondary orientation and were stable in properties.

As shown in Table 3, regarding the contact method between the adsorbent and the tea extract, in the case of the batch method, although precipitation is effectively suppressed, the flavor and taste tend to be lost. For this reason, the column type is considered preferable. Even in the column type, in the case of the sample 16 where the contact time is too short as 1 second, orientation / precipitation is observed, and in the case of the sample 20 where the contact time is as long as 80 seconds or longer, the flavor / taste tends to be lost. It is in. In comparison, Samples 17 to 19, which have a contact time of 2 to 30 seconds, are excellent in balance of taste, flavor and properties even after constant temperature treatment at high temperature. In particular, in Samples 17 and 19, a green tea beverage having good properties while being rich in taste and flavor can be obtained.
Therefore, by producing so as to satisfy the requirements of the present invention, secondary ori-precipitation that occurs over time is suppressed while having the natural turbidity and good flavor inherent in tea, and is stable over time. A beverage is obtained.

The present invention has the natural turbidity and good flavor inherent in tea, while improving the efficiency of selectively removing water-soluble unnecessary components such as ingredients causing sediment and bitterness and bitter taste, and is stable over time. A highly functional tea beverage and a method for producing the same are provided. Moreover, it is an excellent manufacturing method suitable for industrial production in that a large amount of processing can be performed in a short time, and is useful as a method for manufacturing a tea beverage.

Claims

Extracting tea leaves to obtain a tea extract;
An adjustment process for adjusting the tea extract by filtering the tea extract;
A step of bringing the tea extract after the adjustment step into contact with an adsorbent,
A method for producing a tea beverage, wherein the macropore volume of the adsorbent is less than 1.0 cc / g, and the ratio of the macropore volume to the micropore volume is 0.1 to 12.0.
The method for producing a tea beverage according to claim 1, wherein the adjustment step further includes an additional adjustment for adjusting the ratio of the suspended solid content in the tea extract to the soluble solid content to be 15 to 100.
The method for producing a tea beverage according to claim 1 or 2, wherein the adjustment step further includes an additional adjustment in which the electric conductivity of the tea extract is adjusted to 0.5 to 3.0 µS / cm.
The ratio of the mesopore volume (C) to the micropore volume (B) of the adsorbent [C / B] is 0.1 to 20.0. Production method.
The method for producing a tea beverage according to any one of claims 1 to 4, wherein in the step of bringing the tea extract after the adjustment step into contact with an adsorbent, the tea extract is brought into contact with the adsorbent 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.
Extracting tea leaves to obtain a tea extract;
A method for producing a tea beverage comprising: adsorbing a tea adsorbent with a porous adsorbent having micropores to selectively adsorb a component having a molecular weight of 1000 or less.
Furthermore, it has the adjustment process which adjusts the tea extract before the said adsorption process to the state suitable for selective adsorption, The said adjustment process manufactures the tea drink of Claim 7 including filtration separation and centrifugation. Method.
The adjustment step has an additional adjustment for adjusting the amount of suspended solids, soluble solid content, electrical conductivity and pH of the tea extract before the adsorption step, and the additional adjustment includes dilution with water. 8. A method for producing a tea beverage according to 8.