JPH08228734A - Preparation of green 'tochu' tea - Google Patents

Abstract

PURPOSE: To prepare a TOCHU (Euonymus tricocarpus) tea having green color and keeping the taste, flavor and effectiveness while suppressing the decrease in the contents of catechins, amino acids, sugars and vitamin C. CONSTITUTION: This green TOCHU tea can be prepared by washing raw leaves of TOCHU with ion-exchanged water free from heavy metal ion, immersing the washed raw leaves in one or more kinds of solutions selected from water heated to 50-100 deg.C, a saline water having a concentration of 3-300g/L and a solution of a mixture of ascorbic acid and sodium chloride of 3-300g/L concentration to deactivate the oxidase in the raw leaves, cooling and draining the leaves, adjusting the water-content of the leaf to 0.1-15% by passing air adjusted to <=70% relative humidity and 10-60 deg.C through the leaves and crushing the leaves while adding 0.1-115g/kg of ascorbic acid to the leaves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a new green Tochu tea. More specifically, the present invention prevents denaturation and scattering of raw leaf components in the tea making process as much as possible, that is, while maintaining the flavor and effectiveness as Tochu tea, catechins as bitter and astringent components, umami components. The present invention relates to a method for producing green-colored Tochu tea, which minimizes the decrease in the amounts of amino acids as a base, sugars and vitamin C as a sweetening component, particularly catechins and vitamin C.

[0002]

2. Description of the Related Art Tonaka, whose Japanese name is Hamaimayumi, is a deciduous tree (height: about 20 meters) of the Eucommia family, whose origin is in the central west of mainland China. The Tochu leaf part resembles an elm leaf, which is collected, dried and finely cut, and the cut leaves are cut at 60 to 100 ° C for 40
By performing roasting processing by steam roasting for minutes, and further powder processing, so-called Tochu-cha tea products as drinkable tea are manufactured. In addition, the dried stems of Tochu, especially the bark, are known as Tochu or Toruchu and are recognized as a herbal medicine as a tonic.

The Tochu tea produced as described above is
Contains no caffeine, calcium, iron, zinc,
Due to its abundant content of potassium and carotene, it is one of the teas that has been attracting attention in recent years with the spread of health drinks, and it can be used in various forms such as powder, tea bag or canned tea. It is commercially available. Further, since Tochu tea has various advantages as described above, not only is it drunk as tea, but it is currently marketed as noodles and candy containing Tochu tea leaves. At this time, Tochu tea has a brown color in general, which is different from the green color of green tea that Japanese people generally prefer. This is due to the production of theaflavins and thearuvidins by enzymatic action or autoxidation of catechins (tea tannins), reduction of vitamin C (ascorbic acid), and production of browning substances by the reaction of amino acids with sugars or catechins. Is. Green is a color that generally stabilizes the mind, and development of green Tochu tea is desired in terms of mental aspects and also because it contains chlorophyll.

On the other hand, regarding the taste of tea, catechins such as epigallocatechin gallate, epicatechin gallate, epigallocatechin and epicatechin have a bitter and astringent taste, and theanine, glutamic acid, aspartic acid, arginine,
Amino acids such as alanine and serine have a delicious taste,
Furthermore, sugars such as sucrose, glucose and fructose have a sweet taste, and the balance of these sugars determines the taste of tea. Therefore, when the catechins, amino acids and sugars are reduced, the bitterness and astringency of the catechins are reduced, but the umami of the amino acids and the sweetness of the sugars are also reduced, so that the overall taste of the tea becomes pale.

[0005] In addition, C ₆ vitamin C, also called ascorbic acid, which is abundant, such as fresh fruit (oranges, lemon, grapes) and vegetables (tomatoes, cabbage) and green tea
It is a compound having a molecular formula of H ₈ O ₆ and a melting point of 190 to 192 ° C. (decomposition), and is a water-soluble vitamin having anti-scurvy activity. Vitamin C is the largest amount of vitamins needed, and adult males and females need only 1
It is said to be about 60 to 100 mg / day per individual. However, since humans also lack γ-lactonase that synthesizes ascorbic acid and hydrolyze dehydroascorbic acid, vitamin C cannot be synthesized in the body. For this reason, humans need to take vitamin C in the form of tablets or in the form of food containing vitamin C. However, if the intake of vitamin C is low or vitamin C is not taken, scurvy and infants may be involved. Deficiency that is peculiar to vitamin C, such as delayed development of swelling and swelling of knees and ankles. Moreover, it is generally well known that nutrients such as vitamin C are absorbed more efficiently from the fruits, vegetables, or teas as described above, than when they are taken in the form of drugs such as tablets. That is what is being done. Therefore, it is very important for humans to drink Tochu tea containing a large amount of vitamin C and to efficiently absorb vitamin C in the body.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method of manufacturing green-colored Tochu tea.

Another object of the present invention is to prevent denaturation and scattering of fresh leaf components as much as possible, and to maintain the flavor and effectiveness of Tochu tea, while maintaining the amount of catechins, amino acids, sugars and vitamin C, In particular, it is to provide a method for producing a green-colored Tochu tea that suppresses the decrease in the amounts of catechins and vitamin C to the minimum.

[0008]

[Means for Solving the Problems] The above-mentioned object is to wash fresh leaves of Tochu with deionized water from which heavy metal ions have been removed, and wash the washed fresh leaves with warm water heated to 50 to 100 ° C., 3 to 300.
The oxidase present in the fresh leaves was lost by immersing it in at least one solution selected from the group consisting of saline solution having a concentration of g / liter and ascorbic acid having a concentration of 3 to 300 g / liter and sodium chloride. After activating, the water content of the leaves is adjusted to 0.1 to 15% by cooling, draining water, and circulating air in which the relative humidity is 70 or less and the temperature is set to 10 to 60 ° C. The present invention is accomplished by a method for producing green eucommia tea, which comprises crushing tea leaves while adding 0.1 to 115 g / kg of ascorbic acid.

The present invention shows a method for producing green eucommia tea in which the treatment for inactivating the oxidase of the fresh leaves is carried out by immersing in warm water at 80 to 100 ° C. for 3 seconds to 5 minutes. The present invention also provides a process for inactivating green leaf oxidase by immersing the raw leaf oxidase in an aqueous sodium chloride solution having a concentration of 3 to 300 g / liter at 80 to 100 ° C for 3 seconds to 5 minutes. It shows a method. In the present invention, the treatment for inactivating the oxidase of the fresh leaves is performed in a mixed liquid of ascorbic acid and sodium chloride at 80 to 100 ° C in which the mixing ratio of ascorbic acid and sodium chloride is 3: 1000 to 1000: 3. The present invention shows a method for producing green Tochu tea which is carried out by immersing in green soup for 3 to 5 minutes. The present invention further shows a method for producing green eucommia tea in which the water content of leaves is adjusted to 5 to 10%.

[0010]

The method for producing green Tochu green tea according to the present invention is as follows: the fresh leaves of Tochu are washed with ion-exchanged water from which heavy metal ions have been removed, and the washed fresh leaves are heated to 50 to 100 ° C. with warm water of 3 to 300.
The oxidase present in the fresh leaves was lost by immersing it in at least one solution selected from the group consisting of saline solution having a concentration of g / liter and ascorbic acid having a concentration of 3 to 300 g / liter and sodium chloride. After activating, the water content of the leaves is adjusted to 0.1 to 15% by cooling, draining water, and circulating air in which the relative humidity is 70 or less and the temperature is set to 10 to 60 ° C. The method comprises crushing tea leaves while adding 0.1 to 115 g / kg of ascorbic acid.

The present invention will be described in detail below.

FIG. 1 is a flow chart showing an embodiment of the method for producing green Tochu tea according to the present invention. The manufacturing method of the green Tochu tea shown in FIG. 1 will be described in detail below. Raise 1-year-old seedlings, grow seedlings until 5th-year mature trees by fertilization management (pesticide-free and organic farming method), harvest only sunny high quality leaves from late June to early September, and harvest The fresh leaves are treated with heavy metal ions (Fe ²⁺ , Cu ²⁺ and Zn ²⁺
Etc.) and then washed with ion-exchanged water for 3 to 30 minutes,
Immediately heated to 50 to 100 ° C, preferably 80 to 100 ° C, more preferably 95 to 99 ° C, 3 to 300 g /
Ascorbic acid (vitamin C) at a concentration of liter, preferably 10 to 200 g / liter, especially 10 g / liter
It is localized in the epidermal cells of tea leaves by immersing it in a mixed solution of sodium chloride and sodium chloride for 3 seconds to 5 minutes, preferably 4 seconds to 1 minute (hereinafter, the above treatment may be referred to as “heat treatment”). It inactivates the catechin oxidase that is being used to prevent browning of tea and alteration and scattering of catechins. After soaking for a predetermined time, immediately after cooling in cold water or running water at 0 to 15 ° C., draining water while avoiding direct sunlight, relative humidity (RH) is 70 or less, preferably 10 to 20 and temperature is 10 to 60. The water content of the leaves is adjusted to 0.1 to 15%, preferably 5 to 10%, and ascorbic acid is added to the leaves at 0.1.
By crushing while adding ~ 115 g / kg, preferably 10-100 g / kg, and vacuum packaging or nitrogen filling packaging with aluminum foil, a green Tochu tea product is obtained.

In the above embodiment, the mixing ratio (ascorbic acid: sodium chloride) in the mixed solution of ascorbic acid and sodium chloride is 3: 1000 by weight.
1000: 3, preferably 1: 100 to 100: 1, especially 1:70. When the ratio of ascorbic acid exceeds the upper limit of the above range, there is a drawback that the manufacturing cost becomes high. On the other hand, when the ratio of ascorbic acid is below the lower limit of the above range, the oxidation of the fresh leaves during the inactivation treatment of the oxidase is recognized as a significant difference, which is not preferable.

In the above embodiment, the heat treatment for inactivating the catechin oxidase localized in the epidermal cells of tea leaves to prevent browning of tea and alteration and scattering of catechins is performed using ascorbic acid. And a mixed solution of sodium chloride was used, but 50 to 100 ° C., preferably 80 to 1
The heat treatment may be carried out by immersing in warm water or saline (sodium chloride aqueous solution) heated to 00 ° C, more preferably 90 to 95 ° C for 3 seconds to 5 minutes, preferably 30 seconds to 3 minutes. When the temperature of the heat treatment, that is, the temperature of the hot water, the salt solution, or the mixed solution of ascorbic acid and sodium chloride deviates from the range of 50 to 100 ° C, the Tochu tea is browned, and particularly high temperature treatment such as conventional roasting treatment is performed. When it is carried out for a long time (90 to 100 ° C. for 20 minutes), there arises a problem that a low molecular weight amino acid or a low molecular weight peptide is produced, the flavor is impaired, and catechins are altered or scattered.

In the present invention, the concentration of sodium chloride in the solution or the concentration of ascorbic acid and sodium chloride when the salt solution or the mixed solution is used for the heat treatment is 3
~ 300 g / l, preferably 30-100 g / l, especially 50 g / l. This concentration is 3g
If it is less than 1 liter / liter, there is a drawback that browning of fresh leaves is likely to occur due to heat treatment. On the other hand, if the concentration exceeds 300 g / liter, there arises a problem that salt damage to fresh leaves is significant and the cost is economically increased.

In the present invention, the heat treatment time is 3 seconds to
It is 5 minutes, preferably 4 to 30 seconds. If the heat treatment time is less than 3 seconds, the deoxidization of the oxidase in the fresh leaves will be insufficient, and the oxidation will progress, and the color tends to change from brown to brown. On the other hand, when the heat treatment time exceeds 5 minutes, the deterioration of the fresh leaves becomes remarkable and the constituents of the fresh leaves, particularly chlorophyll, vitamins and other minerals, elute. The relationship between the treatment temperature and the treatment time in the heat treatment varies depending on the type of immersion solution used and the concentration of ascorbic acid or sodium chloride used, but is, for example, 100 g /
When using a sodium chloride aqueous solution having a concentration of 1 liter, the relationship between the treatment temperature and the treatment time is most preferably 85 ° C. for 10 seconds and 100 ° C. for 4 seconds.

In the above heat treatment, sodium chloride plays a role of preventing elution of constituent components of fresh leaves as much as possible. In addition, ascorbic acid is added to prevent oxidation by dissolved oxygen or air, and further, as described in the prior art, it prevents browning by supplementing the decrease in ascorbic acid which is one cause of browning, Vitamin C is added so that it can be taken abundantly.

In the present invention, the water content of the leaves after circulating air is 0.1 to 15%, preferably 5 to 10%. At this time, reducing the water content of the leaves to less than 0.1%
Although the cost is increased, there are few advantages. on the other hand,
If the water content of the leaves exceeds 15%, there is a disadvantage that the green Tochu tea leaves are altered by water.

Further, according to the present invention, ascorbic acid is added also during pulverization of tea leaves, but this is added to prevent discoloration or deterioration due to air oxidation during processing or during storage. If ascorbic acid is not added at the time of crushing tea leaves, the discoloration and deterioration of green tea will be significant. Further, it is an object to supplement the decrease in ascorbic acid, which is one of the causes of browning, to prevent browning, supplement vitamin C from a nutritional point of view, and make intake of vitamin C rich. The amount of ascorbic acid added when crushing tea leaves is
0.1-115 g / kg, preferably 10-100 g / kg
kg, especially 30 g / kg. At this time, if the addition amount of ascorbic acid exceeds 115 g / kg, the effect commensurate with the addition cannot be obtained, and the addition amount of ascorbic acid is 0.1 g / kg.
When it is less than kg, a sufficient addition effect is not recognized.

In the above embodiment, the Tochu green tea leaves were preserved by vacuum packaging or nitrogen filling packaging with aluminum foil, but a method in which the fresh aroma of tea and the moderate umami and savory flavor are not impaired. The storage method is not limited as long as As another method, specifically,
Examples thereof include a method of storing in a tea can together with a desiccant and an oxygen scavenger and sealing, and a method of further refrigerating and storing the tea can thus sealed, and a method of preventing moisture absorption and oxidation and storing at a low temperature and a dark place.

[0021]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 1-year-old seedlings were raised and grown to 5th-year-old mature trees by fertilization management (no pesticides and organic farming), and only good sunny leaves were obtained from late June to early September. Harvested and harvested raw leaves were treated with heavy metal ions (Fe ²⁺ , Cu ²⁺ and Zn ²⁺
Etc.) was removed for 10 minutes to wash with deionized water.
It is immersed for 5 seconds in a mixed solution of ascorbic acid and sodium chloride (mixing ratio: ascorbic acid: sodium chloride = 3: 5) heated to 100 ° C. and having a concentration of 100 g / liter. Immediately after the immersion, the heat-treated raw leaves are pulled up and immersed in cold water at 10 to 12 ° C. to cool them. Furthermore, water is drained while avoiding direct sunlight, air with a relative humidity of 25 or less and a temperature of 20 to 25 ° C. is circulated, and the water content of the leaves is adjusted to fall within the range of 5 to 7%. By crushing the leaf with controlled water content while adding 30 g / kg of ascorbic acid,
The powder of Tochu tea leaves was obtained. When boiling water was added to the Tochu tea leaves obtained by the above method, the brewed tea had a green color.

Example 2 One-year-old seedlings were raised and grown to a fifth-year-old mature tree by fertilization management (pesticide-free and organic farming method), and only sunny high-quality leaves were obtained from late June to early September. Harvested and harvested raw leaves were treated with heavy metal ions (Fe ²⁺ , Cu ²⁺ and Zn ²⁺
Etc.) for 30 minutes with ion-exchanged water,
Immerse in 100 g / liter concentration of sodium chloride aqueous solution heated to 100 ° C. for 4 seconds. Immediately after the immersion, the heat-treated raw leaves are pulled up and immersed in cold water at 10 to 15 ° C. for 2 minutes to cool them. further,
Drain water while avoiding direct sunlight, circulate air with relative humidity of 25 or less and temperature set to 20 to 25 ° C, and adjust the water content of leaves to fall within the range of 5 to 7%. The powder of Tochu tea leaves was obtained by crushing the leaves whose content was controlled while adding 30 g / kg of ascorbic acid. When boiling water was added to the Tochu tea leaves obtained by the above method, the brewed tea had a green color.

Example 3 One-year-old seedlings were raised and grown to a fifth-year-old mature tree by fertilization management (pesticide-free and organic farming), and only sunny, good-quality leaves were obtained from late June to early September. Harvested and harvested raw leaves were treated with heavy metal ions (Fe ²⁺ , Cu ²⁺ and Zn ²⁺
Etc.) for 15 minutes with ion-exchanged water,
Immerse in warm water heated to 95 ° C. for 5 seconds. Immediately after the immersion, the heat-treated raw leaves are pulled up to 10 to 15 ° C.
It is cooled by immersing it in cold water for 1 minute. Furthermore, water is drained while avoiding direct sunlight, air having a relative humidity of 20 or less and a temperature of 20 to 23 ° C. is circulated, and the water content of the leaves is adjusted to fall within the range of 5 to 6%. 40 g of ascorbic acid was added to leaves with controlled water content.
The powder of Tochu tea leaves was obtained by crushing while adding kg amount. When boiling water was added to the Tochu tea leaves obtained by the above method, the brewed tea had a green color.

Example 4 The amounts of Vitamin C, catechins and flavonoids contained in the Tochu tea product obtained in Example 1 and the commercially available Tochu tea product (Kumiai Tochu tea T101, manufactured by Hoyo Sangyo Co., Ltd.) were determined as follows. High performance liquid chromatography (HPLC)
It measured using.

1) Preparation method of sample 1 g of green eucommia tea powder obtained in Example 1 was added to 100 m of hot water.
It was put in 1 and extracted for 5 minutes while boiling gently, then the extract was rapidly cooled and filtered with filter paper to obtain Sample I. 1 g of the green eucommia tea powder obtained in Example 1 was put into 100 ml of water, cold leached at room temperature for 1 hour, and then filtered with a filter paper to obtain Sample II. Commercially available Du-Zhong tea product (Kumiai Du-Zhong tea T101, manufactured by Yusangyo Co., Ltd.) 1g in hot water
After extracting for 5 minutes while boiling gently, the extract was rapidly cooled and filtered with filter paper to obtain Sample III.

2) High performance liquid chromatography (HPL)
Analysis method by C) HPLC of each sample obtained in 1) under the following analysis conditions
Analysis was carried out. Pump: GL Science Model 576 Detector: Shimadzu SPD-M6A Wavelength CH-1; 278 to 282 nm CH-2; 358 to 362 nm Column: TSK gel ODS 80TM (4.6 mm
φ × 15 cm) Flow rate: 0.6 ml / min Sample amount: 5 μl Elution: Stepwise elution with the following concentration gradient with an acetonitrile aqueous solution 0-4 minutes; 10%, 4-12 minutes; 30%, 12-26
Min; 30%, 26-30 min; 40%.

The results are shown in FIGS. 2 to 4, the peak at a wavelength near 325 nm represents the peak of ascorbic acid (vitamin C), and
The peak at a wavelength of 78 to 282 nm represents the peak of catechins. From these figures, Tochu tea produced by the method of the present invention (ie, Samples I and II)
It was shown that, when extracted with water or hot water, catechins were detected in a considerably larger amount than those produced by the conventional method (Sample III). Also, sample I
Since the amount of catechins detected in 1. was larger than the amount detected in Sample II, it was found that catechins were leached out more by using the hot water extraction method. further,
From these figures, it was also shown that the flavonoid-based components were detected in greater amounts in Samples I and II than in the commercially available Tochu tea products.

Example 5 Samples I, II and III obtained in Example 4 (5 ml each)
Each sample was freeze-dried, the weight was measured, and the extract amount of each sample was compared. As a result, the extract amount of each sample per 1 g of Tochu tea was 432 mg for sample I, 410 mg for sample II, and 338 mg for sample III. From this, the Tochu tea produced by the method of the present invention (ie, Samples I and II) was prepared by the conventional method (Sample II).
It was also found that the extract weight was higher than that of I), and that the extract weight with hot water was higher than that with water.

Example 6 Tochu tea products obtained in Examples 1 to 3 and commercially available Tochu tea products (Kumiai Tochu tea T101, manufactured by Yusangyo Co., Ltd.)
20 g of each was placed in a pre-warmed teapot, and 100 ° C. boiling water (500 ml) was added thereto. Place this on the stove, wait for 1-2 minutes, and when white steam begins to emerge from the mouth of the teapot, remove it from the stove. Pour the Tochu tea into the pre-warmed cup from the teapot.

When the taste of the Tochu tea thus brewed was compared with that of 20 arbitrarily selected men and women, it was brewed from the Tochu tea products obtained in Examples 1 to 3. 19 out of 20 people said that green tea had a green color, and that it had a better flavor than commercially available Tochu tea products.

[0032]

As described above, in the method for producing green Tochu tea of the present invention, the fresh leaves of Tochu are washed with ion-exchanged water from which heavy metal ions have been removed, and the washed fresh leaves are heated to 50 to 100 ° C. Present in fresh leaves by immersion in at least one solution selected from the group consisting of warm water, 3 to 300 g / liter concentration of saline and 3 to 300 g / liter concentration of ascorbic acid and sodium chloride After deactivating the oxidase, the mixture was cooled, drained, and air having a relative humidity of 70 or less and a temperature of 10 to 60 ° C. was circulated to make the water content of the leaves 0.1 to 15.
%, And ascorbic acid 0.1-115
It consists of crushing tea leaves while adding g / kg. By using the production method of the present invention, green-colored Tochu tea is obtained.

In addition, the Tochu tea produced by the production method of the present invention is prevented from denaturing and scattering of raw leaf components in the tea making process as much as possible, and maintains the flavor and effectiveness of Tochu tea obtained by the conventional method. As it is, the decrease in the amounts of catechins, amino acids, sugars and vitamin C was suppressed to the minimum. Therefore, the Tochu green tea obtained according to the present invention has a better flavor than conventional products, and moreover, by drinking, vitamin C can be effectively ingested.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a method for producing green Tochu tea according to the present invention.

FIG. 2 is a chart showing HPLC data for Sample I.

FIG. 3 is a chart showing HPLC data for Sample II.

FIG. 4 is a chart showing HPLC data for Sample III.

Claims (5)

[Claims] 1. A fresh leaf of Tochu is washed with ion-exchanged water from which heavy metal ions have been removed, and the washed fresh leaf is heated to 50 to 100 ° C., warm water, a salt solution having a concentration of 3 to 300 g / liter, and 3 to 300 g / liter. After deactivating the oxidase present in the fresh leaves by immersing it in at least one solution selected from the group consisting of a mixture of ascorbic acid and sodium chloride at a concentration, cooling, draining, and The moisture content of the leaves is set to 0.1 to 15 by circulating the air whose humidity is 70 or less and the temperature is set to 10 to 60 ° C.
%, And ascorbic acid 0.1-115
A process for producing green Tochu tea, which comprises crushing tea leaves while adding g / kg. 2. The treatment for inactivating the oxidase of the fresh leaves,
The method for producing green tochu green tea according to claim 1, which is carried out by immersing in warm water of 80 to 100 ° C for 3 seconds to 5 minutes. 3. The treatment for inactivating the oxidase of the fresh leaves,
The method for producing green Tochu tea according to claim 1, which is carried out by immersing in an aqueous sodium chloride solution having a concentration of 3 to 300 g / liter at 80 to 100 ° C for 3 seconds to 5 minutes. 4. The treatment for inactivating the oxidase of the fresh leaves,
The method according to claim 1, which is carried out by immersing in a mixed solution of ascorbic acid and sodium chloride having a mixing ratio of ascorbic acid and sodium chloride of 80 to 100 ° C. of 3: 1000 to 1000: 3 for 3 seconds to 5 minutes. The manufacturing method of the described green Tochu tea. 5. The method for producing green tochu green tea according to claim 1, wherein the water content of the leaves is adjusted to 5 to 10%.