JP6118888B1 - Method for producing tea extract - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a tea extract from which a tea extract having a good aftertaste and flavor is obtained. A method for producing a tea extract, comprising an extraction step of extracting tea leaves in the presence of 0.1 to 0.5 parts by mass of activated carbon with respect to 100 parts by mass of the tea leaves. [Selection figure] None

Description

  The present invention relates to a method for producing a tea extract.

  Tea drinks such as green tea, oolong tea, and black tea are widely used all over the world. In addition, container-packed tea beverages filled in containers such as cans and plastic bottles have been developed, and many types of container-packed tea beverages are commercially available. For tea beverages, tea leaves are usually extracted with water to obtain a tea extract, which is diluted to an appropriate concentration, adjusted to pH, etc., and then sealed in a sealed container such as a can or a plastic bottle. Has been sold. However, tea beverages may have an unpleasant taste due to various factors such as tea leaf growth conditions, fermentation conditions, extraction conditions such as temperature and time of extracted water. If there is a miscellaneous taste, the flavor is impaired, so a tea extract with reduced miscellaneous taste is required.

  For example, Patent Document 1 discloses an excellent flavor with a strong tea leaf feeling, refreshingness, freshness, sweet aroma, reduced astringency and miscellaneous taste, and overall flavor / balance and ease of drinking. In order to provide a fresh tea leaf extract, a method for producing a fresh tea leaf extract comprising a step of rapidly freezing fresh tea leaves and a step of extracting fresh tea leaf extracts from frozen unground green tea leaves is disclosed. Yes.

  Patent Document 2 is obtained by mixing a tea leaf extract with a powdered tea leaf and a tea leaf extract for the purpose of providing a tea beverage having a bitter and astringent taste without the miscellaneous taste while having the original flavor of tea. A tea leaf beverage is disclosed.

JP 2011-130740 A JP 2012-196148 A

  There are various reports related to tea drinks other than Patent Documents 1 and 2, but it is difficult to obtain a deep tea drink with good aftertaste and flavor by reducing miscellaneous taste. There is also a need to reduce the miscellaneous taste by a simpler method and obtain a deep tea extract with good aftertaste and flavor.

  An object of this invention is to provide the manufacturing method of the tea extract from which a deep tea extract with favorable aftertaste and flavor is obtained.

Means for solving the problems are as follows:
(1) A method for producing a tea extract, comprising an extraction step of extracting tea leaves in the presence of 0.1 to 0.5 parts by mass of activated carbon with respect to 100 parts by mass of the tea leaves.

The preferred embodiment of (1) is as follows.
(2) Extraction of the tea leaves is performed with water at 50 ° C to 95 ° C for 2 minutes to 10 minutes.
(3) In the method for producing a tea extract according to (1) or (2), the activated carbon has a specific surface area of 1000 to 2000 m ² / g and a pore volume of 0.01 to 1.5 cm. ³ / g, and the average pore diameter is 0.1 to 1.0 nm.

  According to the present invention, it is possible to provide a tea extract rich in the original flavor of tea with little miscellaneous taste, good aftertaste and flavor, and a rich body.

  The method for producing a tea extract according to the present invention includes an extraction step of extracting tea leaves in the presence of a specific amount of activated carbon. Below, an example of the manufacturing method of the tea extract which concerns on this invention is demonstrated.

  The method for producing a tea extract according to this embodiment includes an extraction step of extracting tea leaves in the presence of a specific amount of activated carbon, and a filtration step of filtering the extract obtained in the extraction step.

(Extraction process)
Tea leaves, the raw material of tea extract, are pre-treated leaves, buds and stems for tea (Camellia sinensis), an evergreen tree of the camellia family. There are no particular restrictions on the type, grade, production area, production method, etc. of tea leaves, and any tea leaves can be used. The pre-treatment method for tea includes non-fermentation, semi-fermentation, and fermentation, and any pre-treatment method may be used. Examples of non-fermented tea include green tea such as sencha, gyokuro, stem tea, bud tea, kabuse tea, tencha, matcha tea, bancha, hojicha and kamaage tea, and flower tea such as jasmine tea. Jasmine tea is a fragrance of lotus, katsura, coconut, chrysanthemum, etc. Examples of semi-fermented tea include oolong tea. Examples of fermented tea include black tea and pu-erh tea.

  The activated carbon can be used without any particular limitation on its type and characteristics. Extraction of tea leaves is performed in the presence of 0.1 to 0.5 parts by mass of activated carbon with respect to 100 parts by mass of tea leaves, and in the presence of 0.15 to 0.3 parts by mass of activated carbon. More preferably. By extracting tea in the presence of a specific amount of activated carbon, miscellaneous components in the tea extract are selectively adsorbed by the activated carbon, and the flavor component can be retained.

The specific surface area of the activated carbon is preferably from 1000 to 2000 ² / g, and more preferably 1200~1800m ² / g. The pore volume of the activated carbon is preferably from 0.01~1.5cm ³ / g, more preferably from ^{0.08~0.5cm 3 / g, 0.10~0.19cm 3 /} g Is particularly preferred. The average pore diameter of the activated carbon is preferably 0.1 to 1.0 nm. When activated carbon has such a characteristic, it is easy to hold | maintain a flavor component, reducing the miscellaneous taste component of a tea extract. The specific surface area of the activated carbon can be determined by a gas adsorption method, an iodine adsorption method based on JIS K 1474, or the like. The pore volume and average pore diameter can be determined by a mercury intrusion method, a gas adsorption method, or the like. The activated carbon preferably has a ratio of particles having a particle diameter in the range of 0.500 to 0.250 mm of 90% or more. When the particle size of the activated carbon is in the above range, it is easy to separate from the extract after extraction of tea leaves while maintaining the function of reducing miscellaneous components. The particle size of the activated carbon can be measured by sieving according to JIS K 1474.

  Extraction of tea leaves uses water as an extraction solvent. The kind of water is not particularly limited, and can be appropriately selected from tap water, distilled water, ion-exchanged water, natural water and the like. The amount of the extraction solvent used is preferably 15 to 50 times the mass of tea leaves. If the amount of the extraction solvent used is too large, the flavor tends to be diluted. The temperature of water when extracting tea leaves is preferably 50 to 95 ° C, and more preferably 60 to 90 ° C. If the water temperature is lower than 50 ° C, a flavorful tea extract may not be obtained. If the water temperature is higher than 95 ° C, astringency may be increased. The green tea is more preferably 50 to 90 ° C, and particularly preferably 55 to 85 ° C. The jasmine tea is more preferably 60 to 90 ° C, and particularly preferably 70 to 85 ° C. As for oolong tea, it is more preferable that it is 70-95 degreeC, and it is especially preferable that it is 80-95 degreeC. As for black tea, it is more preferable that it is 50-95 degreeC, and it is especially preferable that it is 80-90 degreeC.

  The tea leaves can be extracted with water in the presence of a specific amount of activated carbon to obtain a tea extract with little miscellaneous taste and good aftertaste and flavor. The extraction method of tea leaves is not particularly limited, and a known extraction method such as stirring extraction, column extraction, drip extraction or the like can be employed. Extraction of tea leaves is performed, for example, by pouring tea leaves and activated carbon into water at 50 to 95 ° C., and standing or stirring for 2 to 60 minutes, preferably 2 to 10 minutes. If the extraction time of tea leaves is too long, miscellaneous taste tends to increase.

  In addition, you may add appropriate additives, such as antioxidant, other than a tea leaf and activated carbon at the time of extraction of a tea leaf.

(Filtration process)
Next, the tea leaves and activated carbon are removed by performing one or a combination of two or more solid-liquid separation processes selected from filtration, centrifugation, membrane treatment, and the like on the extract obtained in the extraction step, and tea Obtain an extract.
The filtration method is not particularly limited, and for example, filter separation using a filter paper, a metal filter, a guff filter, or the like can be employed. The mesh size of the metal filter is preferably 20 to 200 mesh in that the solid content of the tea leaves and the activated carbon can be surely removed to obtain a tea extract as a raw material for a tea beverage without any taste.
Centrifugation can be performed using a conventionally known apparatus such as a separation plate type, a cylindrical type, or a decanter type. Centrifugation is preferably performed at a rotational speed of 3000 to 10000 rpm for 0.05 to 10 minutes.
The membrane treatment is, for example, a treatment of passing a membrane made of a polymer material having a pore diameter of 10 μm or less, and examples of the membrane form include a flat membrane and a hollow fiber membrane.

  In this way, a tea extract can be obtained.

The tea extract can produce a tea beverage filled in a sealed container such as a can or a bottle by further passing through a blending step and a filling step.
In the blending process, the pH of the tea extract is adjusted by adding an organic acid such as ascorbic acid, or an alkaline substance such as sodium bicarbonate, sodium hydroxide and sodium phosphate as a pH adjuster to the tea extract. . Moreover, the tea extract is appropriately diluted with water to perform a treatment for setting Brix in the range of 0.1 to 0.4. Brix is the mass (g) of soluble solids per 100 g of tea extract. Brix can be measured with a commercially available refractometer. If Brix is less than 0.1, the flavor of the tea extract tends to be dilute, and if it is greater than 0.4, the tea beverage becomes turbid and precipitation tends to occur.
In the filling process, the tea extract after the preparation process is heat sterilized, filled into beverage containers such as aluminum cans, plastic or glass bottles, and sealed, and then packed into a tea beverage Can be manufactured.

  In the above-described embodiment, the case where the tea extract is used as a packaged tea beverage has been described. However, the tea extract can be used as it is as a tea beverage, and as appropriate forms, various foods and beverages can be used. It can also be added and used. The tea extract may be further concentrated to form a paste or pellet, or may be processed into powder by spray drying, freeze drying, heat drying or the like.

  The tea extract is made into an appropriate form such as a diluent, paste, powder, etc., and then has a tea-flavored food / drink, for example, frozen confectionery such as snacks and ice cream, confectionery such as cookies, jelly and candy, milk It can be added to beverages such as carbonated beverages and breads.

  In addition, the manufacturing method of the tea extract which concerns on this invention is not limited to the said embodiment and the following Examples, As long as the subject of this invention can be achieved, it can change suitably.

Example 1
Into an extractor containing 10 L of water at 78 ° C., 250 g of green tea and 0.5 g of activated carbon (Kuraray Chemical Co., Ltd., “Kuraray Coal GW-H32 / 60”) are added and extracted by stirring for 8 minutes. It was. Subsequently, after filtering with a 70 mesh metal filter, it filtered with a 150 mesh metal filter, and also filtered with the filter paper, the tea leaf and activated carbon were removed from the extract, and the tea extract was obtained.
Next, appropriate amounts of water and baking soda were added to the tea extract to adjust the Brix value to 0.20 and pH 6.0 to 6.2.
Next, after heat sterilization at 138 ° C. for 30 seconds, it was filled into a 280 ml PET bottle and cooled to room temperature to obtain a tea beverage.
The characteristics of the activated carbon used were measured by sieving in accordance with the gas adsorption method and JIS K 1474 as described above. The specific surface area was 1490 m ² / g, the pore volume was 0.148 cm ³ / g, the average fineness The ratio of particles having a pore diameter of 0.4 nm and a particle diameter of 0.500 to 0.250 mm was 90% or more.

(Examples 2 and 3, Comparative Examples 1 and 2)
A tea beverage was produced in the same manner as in Example 1 except that the amount of activated carbon was changed.

(Examples 4-6, Comparative Examples 3 and 4)
A tea beverage was produced in the same manner as in Examples 1 to 3 and Comparative Examples 1 and 2 except that the green tea was changed to oolong tea and the extraction temperature was changed to 90 ° C. and the time was changed to 7 minutes.

(Examples 7 to 9, Comparative Examples 5 and 6)
A tea beverage was produced in the same manner as in Examples 1 to 3 and Comparative Examples 1 and 2 except that the green tea was changed to jasmine tea and the extraction temperature was changed to 80 ° C. and the time was changed to 5 minutes.

(Comparative Examples 7 to 11)
A tea beverage was produced in the same manner as in Examples 1 to 3 and Comparative Examples 1 and 2 except that green tea was changed to barley tea and the extraction temperature was changed to 90 ° C. and the time was changed to 6 minutes.

(Scent of tea drink, aftertaste, and body)
Ten panelists evaluated the fragrance, aftertaste, and body of the tea beverages obtained in Examples 1-9 and Comparative Examples 1-11.
Evaluation was scored according to the following criteria, and the average score of each panel was calculated. The score for comprehensive evaluation is the sum of the aroma, aftertaste, and richness. The evaluation results are shown in Table 1. In addition, in Table 1, the addition amount of activated carbon was shown by the mass part of the activated carbon added with respect to 100 mass parts of tea leaves.
Scent 5 points: Strong 4 points: Slightly strong 3 points: Neither can be said 2 points: Slightly weak 1 point: Weak

Aftertaste 5 points: Clear 4 points: Easy refresh 3 points: Neither 2 points: Not refreshed 1 point: Not refreshed

Body 5 points: Strong 4 points: Slightly strong 3 points: Neither point 2 points: Slightly weak 1 point: Weak

Overall evaluation ◎: 13 to 15 points ○: 10 to 12 points △: 7 to 9 points ×: 6 points or less

As shown in Table 1, for green tea, oolong tea, and jasmine tea belonging to tea leaves, when activated carbon was extracted in the presence of 0.1 to 0.5 parts by mass with respect to 100 parts by mass of tea leaves (Example 1) ~ 9) had a strong aroma and a clean aftertaste compared to the case where no activated carbon was added (Comparative Examples 1, 3, and 5), and it had a rich taste and was clearly superior in flavor. When the added amount of activated carbon is 0.7 parts by mass (Comparative Examples 2, 4, and 6), the aroma is weaker and the aftertaste is worse than when the added amount of activated carbon is 0.1 to 0.5 parts by mass. It was too weak.
Oolong tea had an added amount of activated carbon of 0.1 parts by mass (Example 4), and the aftertaste was considerably improved as compared with Comparative Example 3 in which no activated carbon was added.
Green tea and jasmine tea have an added amount of activated carbon of 0.1 parts by mass (Examples 1 and 7), and the fragrance is stronger than that of Comparative Examples 1 and 5 to which no activated carbon is added. The aroma became very strong with the amount (Examples 2 and 8).
In barley tea, which does not belong to tea leaves, the aroma and body disappeared as the amount of activated carbon increased, and the flavor became like colored water.

(Evaluation after storage of tea beverage)
After storing the PET bottles of Examples 2, 5, 8 and Comparative Examples 1, 3, 5 in an incubator where the temperature in the apparatus is 45 ° C. for 36 days (corresponding to storage at room temperature for 9 months), aroma, aftertaste, The liquid color and pH were evaluated.
All samples had no change in fragrance and aftertaste before and after storage, and the pH was within the specified range, confirming that there was no problem in quality.
For green tea and jasmine tea (Examples 2 and 5, Comparative Examples 1 and 3), although slight precipitation was observed regardless of the presence or absence of activated carbon, it was confirmed that there was no problem in quality.
For oolong tea (Example 8, Comparative Example 5), no precipitation was observed regardless of the presence or absence of activated carbon, and it was confirmed that there was no problem in quality.

Claims (3)

  A method for producing a tea extract, comprising an extraction step of extracting tea leaves in the presence of 0.1 to 0.5 parts by mass of activated carbon with respect to 100 parts by mass of the tea leaves.   The method for producing a tea extract according to claim 1, wherein the tea leaves are extracted with water at 50 ° C to 95 ° C for 2 minutes to 10 minutes. The activated carbon has a specific surface area of 1000 to 2000 m ² / g, a pore volume of 0.01 to 1.5 cm ³ / g, and an average pore diameter of 0.1 to 1.0 nm. The method for producing a tea extract according to claim 1 or 2.