JP2006246714A - Taste-reinforced fermented tea leaf, and thick taste oolong tea beverage utilizing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide taste-reinforced fermented tea leaves richly containing tasty components, in particular, a lot of theanine; to provide a novel oolong tea beverage utilizing tea extract obtained from half-fermented or fermented tea leaves: and to provide a method for producing the fermented tea leaves. <P>SOLUTION: The taste-reinforced fermented tea leaves are obtained through the following process: picking tea leaves from tea trees grown in such a condition as to shield the sun shine with an air-permeable cover having 60-95% of a light-shielding rate for 5-20 days in total during about 20 days just before a day to pick the tea leaves; and subjecting the picked tea leaves to half fermentation or full fermentation. The tea leaves richly contain tasty components of tea, in particular a lot of theanine. The tea extract from the tea leaves is mixed with the tea extract highly containing polymer catechin obtained from the tea leaves fermented so that the amount of the catechin polymer generated through the fermentation process accounts for 50 wt% or more based on 100 wt% of the catechin included in fresh tea leaves, to obtain a novel oolong tea beverage having thick taste and richness, lightness in flavor, and slight astringency. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

Field of Invention

  The present invention relates to a taste-enhanced fermented or semi-fermented tea leaf, a method for producing the same, a oolong tea beverage having a rich taste and flavor produced using the tea extract of the tea leaf as a part of the raw material, and the The present invention relates to a method for producing a beverage.

Conventional technology

  Oolong tea leaves originate from semi-fermented tea produced in Fujian, Guangdong, and the eastern part of Taiwan. There is.

  Oolong tea leaves are picked 4-5 times a year in temperate areas, for example in southern China, but the best tea in spring after dormancy in winter has accumulated nutrients and is highly valued for its aroma and taste. When it comes to bancha or sanbancha, the temperature rises and the sun's rays become stronger, so it grows vigorously. When the sun's rays are strong, the leaves harden quickly, and the twisting is not good. As a result, the tea leaves have a light taste and astringency. Oolong tea made with hard leaves has a thin flavor and strong astringency, so if you use high temperature and strong extraction, you cannot make Oolong tea drink with excellent flavor, so the value of use is limited or low value. It was.

  In China, oolong tea has gained popularity due to the expansion of demand for tea leaves due to economic development. However, in order to sell oolong tea to people who have been drinking green tea, green tea type tea leaves with less fermentation than before are produced. . In other words, the recent trend is shifting the emphasis to strengthening the aroma by suppressing fermentation. However, the secret that oolong tea has a rich flavor despite the small amount of amino acids compared to green tea is that the catechins in the tea leaves are polymerized to semi-ferment the tea leaves, and the molecular weight of oolong tea, a unique oolong tea polyphenol of about 1000 to 4000 It is necessary to produce polyphenols and produce richness unique to oolong tea. Therefore, if fermentation is not performed sufficiently, there is a problem that only oolong tea with strong aroma but light taste can be obtained. In fact, there are many such products in China.

In China, the consumption of oolong tea is growing rapidly as described above, and tea picking is carried out five times a year in temperate tea gardens. This, combined with the tendency to suppress fermentation, is the cause of the problem that only oolong tea with a scent but very light taste can be obtained. In other words, the best tea in spring is rich in flavor and fragrant, but the tea from the end of May to July, which is the second and third teas (called summer tea and hot tea), and the fourth and fifth teas gradually. There is a problem that a tea with a strong astringency and light taste becomes a low value tea.
[Problems to be solved by the invention]

  The present invention is a special devise from the time of cultivation of tea leaves as a raw material, not only for the first tea, but also for the tea leaves after the second tea, the taste components of tea (especially amino acids exhibiting umami components, It aims at establishing the manufacturing method of the tea leaf which is especially rich in theanine).

  The present invention also provides a beverage having a strong umami-rich and low astringency, and a food and drink containing the beverage, comprising a tea extract obtained by semi-fermenting or fermenting the tea leaves obtained by the above-mentioned production method. The purpose is to provide.

The present invention also provides a novel oolong tea beverage having a rich and rich taste and a light and gorgeous flavor.
[Means for solving the problems]

  In the first aspect, the present invention grows a tea tree by shading sunlight with a cover having an air permeability of 60 to 95% for a total of about 5 to 20 days, within a total of about 20 days immediately before the tea leaves are picked. And a method for producing tea leaves obtained by semi-fermenting or completely fermenting tea leaves obtained by picking tea leaves from tea trees grown by the method, and without light shielding Except for this, it is a tea leaf characterized in that the taste components are enhanced compared to those grown under the same conditions.

  When the sun rays are shielded during the above period, the tea leaves can be kept fresh and soft, and leaves with abundant umami components and less astringency can be obtained. This effect is not exhibited if the light shielding rate is less than 60%, but if the light shielding rate is greater than 95%, the growth of tea tree is inhibited. A preferable light shielding degree is 70 to 90% for 6 to 15 days, and particularly preferably 75 to 85% for 8 to 12 days. The light shielding may be performed continuously or intermittently. The preferred material for shading is a cloth such as cold koji, and this cloth can be used to cover the tea tree for convenient shading, but any material can be used as long as it can shield light without affecting the growth of the tea tree. is there.

  Oolong tea, black tea, white tea, yellow tea and jasmine tea for the production of fermented or semi-fermented tea and weakly fermented tea as types of tea suitable for enhancing the taste components of tea leaves by growing in the dark Illustrative examples are fried blue and Honchin (both blue) green tea, which are raw tea materials for flower teas.

  The extraction of tea leaves from tea trees grown in the dark as described above is preferably carried out by open-surface sampling. That is, picking is performed when 2 to 5, preferably 3 or 4 leaves are opened and no buds are left. Therefore, 20 days immediately before this point is a period for performing the light shielding process in the present invention. Whether or not it is within about 20 days immediately before the time point can be determined by the actual tea making results and the bud growth status of each year, and those skilled in the art have a precision of ± 2 days. The reason for not picking at the bud stage is that even if the shoot is picked, it is soft in the manufacturing process of oolong tea and it will not fall off, so it is more convenient to pick it when the tea leaves are quite open. Even if it is plucked at the stage, the quality itself as oolong tea itself is nothing.

  The tea leaves plucked from tea trees grown in the dark are rich in the flavor components of tea, especially the amino acids that exhibit umami components, such as especially theanine, so they are rich when extracted as is or after fermentation or semi-fermentation. Give a delicious tea extract. Therefore, in a preferred embodiment of the present invention, when using summer tea or hot tea as a raw tea leaf, and further using Sanbancha to Banbancha, by growing the tea tree in the shade as described above, The taste of summer tea or hot tea, which is said to be inferior in taste component, can be improved, and fermented tea leaves having the quality equivalent to the most tea can be provided.

In the present invention, tea leaves picked from a tea tree grown in the dark are used after being fermented or semi-fermented. There is no particular limitation on the method from picking to producing fermented or semi-fermented tea, and any method for producing oolong tea may be used. To illustrate a typical method, it is performed as follows:
Picking → Sun-dried (bleached blue: Saichin) → Shade-dried (cool blue: Liang Chin) → Saku Blue (Cotchin) → Frozen blue (Chao Chin) → Loinen → Paolo → Dry (▲ both ▼ ro: Hong Pei).

  Sun-dried and shade-dried are also known as wilt, which stimulates the excitation of enzymes before starting fermentation, and activates hydrolases and oxidases. Sakusui repeats Yaochin and cool blue, which are stirred at a certain temperature during the fermentation process, and promotes the generation of a fragrance unique to oolong tea. When sufficient scent components are generated, heat (fried blue) to reduce the enzyme's function to the point where it does not completely disappear, and then twist. Spice is fermented by touching the air with catechins in the extract that comes out after crushing the cells of the tea leaves. In some cases, the tea leaves may be rounded by repeating wrapping while being rolled with a machine by wrapping in a cloth. Finally, drying is performed to produce crude tea (raw tea). Thereafter, the handle and stem of the tea leaf, those with poor appearance and those that have been crushed are removed, and then heating is performed mainly for drying to obtain the fermented or semi-fermented tea leaf of the present invention. Here, in the present specification, the semi-fermentation treatment means that the enzymes of the tea leaves themselves are partially acted to change the scent and taste of the tea leaves, and the complete fermentation treatment means the enzymes of the tea leaves themselves. It means to change the scent and taste of tea leaves by acting all over.

The present invention also relates to a food or drink using the tea extract obtained from the semi-fermented or fermented tea leaves of the present invention. In order to obtain a tea extract, it means an extract obtained by extracting tea leaves with about 15 to 150 times the amount of water, warm water or hot water, optionally in the presence of an alkali salt for 1 minute to 10 hours. When the tea leaf of the present invention is extracted by a normal extraction method, it contains at least 5 mg / 100 ml or more of theanine, and depending on the extraction method, theanine can be further contained in a higher content. In order to use the tea extract for food and drink, the tea extract itself of the present invention may be used, or a concentrate (concentrated extract) or a dried product thereof may be used. Therefore, in this specification, when it is called a tea extract, what concentrated according to the meaning and dry matter are also included. The food and drink using the tea extract of the present invention may be a food and drink made of the tea extract itself, or may be a food or drink obtained by adding the tea extract to the food or drink. A preferred food or drink using the tea extract of the present invention is oolong tea or oolong tea beverage. Oolong tea beverage means a beverage produced by adding or blending Oolong tea extract or its concentrate or dried product.

Novel Type Oolong Tea Beverage In the second aspect, the present invention provides a novel Oolong tea beverage comprising the tea extract of the present invention mixed with another tea extract. That is, the tea extract (hereinafter referred to as the first tea extract) that is rich in theanine content and has a richer taste obtained from the above fermented or semi-fermented tea leaves of the present invention, and catechin contained in fresh tea leaves 100% of the catechin polymer produced through the fermentation process is obtained from tea leaves fermented until the amount exceeds 50%. It is a food and drink with a rich umami and richness, light flavor, and little astringency, characterized by containing a tea extract (hereinafter referred to as a second tea extract) ( Hereinafter, the food and drink in the second aspect of the present invention may be referred to as a second food and drink).

  The first tea extract is the tea obtained in the first aspect of the invention, and contains at least 5 mg / 100 ml of theanine. However, it can be made higher in content depending on the extraction method, and preferably 10 mg / 100 ml. More preferably, it contains 15 mg / 100 ml or more. In addition, even if it is the tea extract extracted from raw materials other than the tea leaf grown by the light-shielding method of this invention, what contains theanine in said quantity can be used as a 1st tea extract similarly. It can be confirmed by HPLC (liquid chromatography) that the tea extract contains theanine in the above amount.

  The second tea extract is an extract obtained from tea leaves fermented until the amount of catechin polymer produced through the fermentation process exceeds 50% with respect to 100% catechin contained in fresh tea leaves. The tea leaves that have been fermented to more than 50% are originally converted to polymers or oxidants due to fermentation and oxidation when the total amount of catechin contained in fresh tea leaves is 100. , The amount of change is more than 50% of the total amount of catechin. In general, when the degree of fermentation increases, the total amount of catechin itself does not change and the ratio of the polymer increases. Here, the catechin polymer is also called a polymerized catechin, and is used in the same meaning as the high-molecular polyphenol, and is a term including a catechin polymer having a dimer or higher. Accordingly, a tea extract containing more catechin polymer than the above value can be easily obtained by fermenting tea leaves used for fermentation, for example, tea leaves of Honyama tea for color oolong tea under appropriate fermentation conditions for a relatively long period of time. . The amount of catechin polymer contained in the tea extract can be confirmed by HPLC (liquid chromatography).

  In a preferred embodiment, the second food or drink of the present invention has a content ratio of the first tea extract and the second tea extract of 9: 1 to 2: 8, more preferably 7: 3 to 4: 6. It is. The content ratio has both umami and kokumi as compared to the case of only the first tea extract containing a large amount of theanine or the case of only the second tea extract containing a large amount of polymer catechin, This ratio is optimal for having no astringency peculiar to tea and having a favorable flavor. That is, when the polymer rich content is 9: 1 or less with respect to the theanine rich content, the richness of the polymer rich content is not sufficiently imparted. In addition, when the polymer-rich content is 2: 8 or more with respect to the theanine-rich content, the extraordinary flavor component of the polymer-rich content becomes strong, but it cannot be said to have a good flavor. Therefore, it is preferable to blend in this optimum range.

  There is no particular limitation on the mixing or blending method of the first tea extract and the second tea extract, and both can be mixed at the above blending ratio in a liquid state. Alternatively, one or both tea extracts can be made into a concentrated extract or a dry powder and then used for blending.

The preferable aspect of the 2nd food / beverage of this invention is a oolong tea drink. This is an aqueous beverage in which the first tea extract and the second tea extract are blended in the above ratio. This drink is a new type of oolong tea, which is equivalent in terms of richness when compared to conventional oolong tea, but it has a rich flavor, light and gorgeous fragrance, less bitterness, color clarity, etc. Because it can be clearly distinguished in terms, it is referred to herein as Oolong tea beverage. Conventionally, since the production of flavor during fermentation is suppressed when the theanine content of tea leaves is increased, it has been avoided to grow the tea tree for fermented tea while shading it. On the other hand, the oolong tea beverage of the present invention is a tea extract from a fermented or semi-fermented tea leaf containing a large amount of taste components such as theanine, which is obtained by shading tea trees and growing them, and polymerizing catechins. A new type of oolong tea beverage of the present invention could be produced by mixing in a predetermined ratio with tea extract from tea leaves sufficiently fermented to contain a large amount.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited only to an Example.

Example 1
(1) An experiment was conducted during the period from July 20th to July 31st using a tea tree for oolong tea in a tea plantation in Longtan Town, Anhui County. A tea tree covered with a cold chiller with a shading rate of 40, 60 or 80% for the first 15, 10, 5 or 0 days immediately before the expected date of plucking, and the taste of the tea leaves plucked is a control with a shading rate of 0% Compared with. The comparison was conducted by sensory evaluation by three experts. When the light shielding ratio was 60 and 80%, the taste of tea leaves was significantly improved by the light shielding treatment for 5 to 15 days. It was not possible to carry out the shading of 80% or more because it would be sunburned after the treatment was finished and the shading was stopped. Table 1 shows the results of improving the taste of tea leaves obtained when the light shielding rate is 80%. In Table 1, “slightly dark” indicates that there is a little effect, “dark” indicates that there is an effect, and a blank indicates that there is no difference from the control.

(2) The amino acids theanine, aspartic acid, and glutamic acid contained in tea leaves grown under each condition of (1) were analyzed. Table 2 shows the analysis value of the tea leaf sample under the 80% light-shielding condition. The tea leaves were extracted at 3 g / 120 cc for 5 minutes at 85 ° C., and the extract was diluted 3 times to measure amino acids. Amino acids such as theanine, aspartic acid, and glutamic acid increased in tea leaves subjected to 60% or 80% shading for 5 days or longer, depending on the timing of germination. Table 2 shows the results at 80% light shielding.

(3) In catechins, the production of catechin was suppressed in about 10 days, but the production amount increased again when the light shielding was prolonged. Among catechins, catechins (also referred to as adsorbed catechins) such as EGCg and ECg, which greatly affect astringency, are similar, and it has been found that after 10 days, astringency increases again. In contrast to catechin, the amount of caffeine that affects the bitterness increased if light-shielded. However, as theanine increases, the sweetness increases and the taste increases, so the effect of caffeine is considered not to significantly affect the taste.

(4) Oolong tea was made using Oolong tea leaves manufactured at the above 80% shading rate, and compared with that made with conventional tea leaves. Oolong tea was produced by the following method.
Weighing tea leaves → Extraction (extraction with hot water of 70-90 ° C) → Solid-liquid separation → Filtration → Cooling → Preparation → Heat sterilization → Filling (plastic bottle) → Cooling → Packing

The tea leaves were prototyped with three extraction temperature levels using both tea leaves made with 80% shading and covered for 10 days, and tea leaves made without shading at the same tea garden. The amount of tea leaves used was 15 g / 1000 ml for each group and filled into PET bottles.

A professional evaluator evaluated the flavor after one week of trial production. Table 4 shows the evaluation results.
The extraction conditions were 70 ° C., 80 ° C., and 90 ° C., and extraction was performed for 5 minutes while maintaining the temperature. Except for the temperature, almost the same extraction conditions were used.

The tea leaves that were not shaded were summer teas, so there were many hard leaves and the amount of extract tended to be slightly worse than usual. On the other hand, the tea leaves subjected to the shading treatment were soft and the extract was well extracted, and the desired quality was obtained. From this experiment, it was found that the Oolong tea beverage with light-shielding has a rich taste and astringency is reduced, and a good beverage can be obtained even if the extraction temperature is increased. In addition, 60-95% of the light is shaded to soften the stems and leaves of the tea so that it can be easily twisted during the production of oolong tea, and the finished wrapping is also strongly applied to enhance the umami taste. Was made.

Example 2
The same tea tree as in Example 1 was treated for 5 days, 10 days, and 15 days with a light shielding rate of 40%, 60%, and 80% from September 16 to September 30, and the resulting tea leaves were exhibited. The taste was evaluated as in Example 1. The results are shown in Table 5.

Analysis of the amino acid theanine was also performed in the same manner as in Example 1, and similar results were obtained. The results are shown in Table 6. Amino acids such as theanine were clearly effective at 80% shading, but 60% shading showed the same tendency as 80%, and 60% shading had a lasting effect in 5 days. (The result of 80% is omitted because it is clear that amino acids such as theanine are contained more than 60% as shown in Table 1 of Example 1. In the case of 5 days, it was influenced by the time and place. (It seems to be more effective than 40% shading.)

Example 3
For the purpose of developing a new type of oolong tea beverage, the theanine-rich tea extract analyzed as having a theanine content of 5 mg / 100 ml or more in the above examples, and the polymer catechin amount is 50% or more with respect to the total catechin amount. The resulting polymer catechin-rich tea extract was prepared.

  Here, the theanine-rich tea extract is an extract from unfermented tea leaves. The reason for extracting from unfermented tea leaves is that tea leaves with a lot of theanine are not hydrolyzed even if they are fermented, so the fragrance is difficult to be produced and the meaning of making theanine diminishes if polymerized catechins are made by fermentation. It is. Because theanine is relaxed and polymerized catechin is rich, it feels different. If there is much theanine, it will become a soft flavor, but if there is much polymerized catechin, it will become a hard flavor. Further, when catechin is polymerized, the color becomes darker depending on the molecular weight, but the unfermented tea leaf extract has a light color because the amount of liquid polymerized catechin is small.

  The above-mentioned polymer catechin-rich tea extract is made from the following tea leaves: plucking → sun-dried (bleached blue: Saichin) → shade-dried (cool blue: Liang Chin) → long-time fermentation (Saku Blue: Tsuchin) → fried Blue (Chaochin) → Ronen → Dry (▲ bo ro: Hong Pei) is extracted with about 15 to 150 times the amount of water, warm water or hot water, optionally in the presence of an alkali salt for 1 minute to 10 hours. It is the extract obtained by doing.

  A professional evaluator evaluated the taste and flavor of a tea beverage in which these tea extracts having different personalities were blended in the following ratios, respectively. The evaluation standard was 5.0 to 1.0. As a result, it was possible to obtain a tea beverage having a rich taste having an umami taste and a rich taste with a rating of 4.0 or higher, and a light and astringent taste, but a flavor unique to oolong tea. In the case of only theanine-rich tea extract, there is umami, but in order to further add richness, by adding about 10-80% polymer rich tea extract, it is rich in umami and richness I could feel the taste. In addition, by setting the polymer-rich tea extract to this ratio, a color tone as a general oolong tea can be exhibited, and the oolong tea beverage that is preferable in appearance when used in a transparent container-packed beverage was obtained.

Claims (17)

A total of 20 days immediately before the tea leaf picking date, for a total of 5 to 20 days, grow a tea tree with light-shielding covering with 60 to 95% light-blocking rate, and remove the tea leaf from the tea tree. A semi-fermented or fermented tea leaf obtained by semi-fermenting or completely fermenting a dried tea leaf and having enhanced taste components as compared with those grown under the same conditions except that it is not shaded. 2. The tea leaf according to claim 1, wherein the tea is shielded by covering the tea tree with a cold koji with a shading rate of 60 to 95% or the like. The tea leaves according to claim 1 or 2, wherein the tea leaves are summer tea or hot tea. The tea leaf according to any one of claims 1 to 3, which contains 50 μM or more of theanine when measured by diluting an extract obtained by extracting 3 g of tea leaf with 120 ml of water for 5 minutes three times with water. A food or drink containing the tea leaf according to any one of claims 1 to 4 or a tea extract obtained from the tea leaf. The food and drink according to claim 5, which is oolong tea. A total of 20 days immediately before the tea leaf picking date, for a total of 5 to 20 days, grow a tea tree with light-shielding covering with 60 to 95% light-blocking rate, and remove the tea leaf from the tea tree. A method for producing semi-fermented or fermented tea leaves, comprising subjecting the tea leaves to semi-fermentation or complete fermentation. 8. The production method according to claim 7, wherein the light is shielded by covering the tea tree with a cold koji having a light shielding rate of 60 to 95% or the like. The method according to claim 8, wherein the tea leaves are summer tea or hot tea. It is characterized in that the tea tree is grown by shading the sunlight with a breathable covering with a light shielding rate of 60 to 95% for a total of 5 to 20 days within the 20 days immediately before the picking date of the tea leaves of summer tea or hot tea. How to grow summer tea or hot tea. The growth method according to claim 10, wherein the shading is carried out by covering the tea tree with a cold koji with a shading rate of 60 to 95% or the like. It produced | generated through the fermentation process with respect to the tea extract (henceforth the 1st tea extract) obtained from the tea leaf of any one of Claim 1 thru | or 4, and 100% of catechin contained in a fresh tea leaf. A food and drink comprising a tea extract obtained from tea leaves fermented until the amount of catechin polymer exceeds 50% (hereinafter referred to as a second tea extract). A tea extract (first tea extract) obtained from the tea leaves according to any one of claims 1 to 4, and a high concentration of catechin polymer having a catechin polymer amount of 50% or more with respect to the total catechin amount A food or drink comprising a tea extract containing a coalescence (hereinafter referred to as a second 'tea extract). The amount of catechin polymer produced through the fermentation process with respect to 100% catechin contained in tea leaves (hereinafter referred to as 1 'tea extract) containing 5mg / 100ml or more of tea leaf-derived theanine A food or drink comprising an extract (second tea extract) obtained from tea leaves fermented to a content of more than 50%. Tea containing tea leaf-derived theanine 5mg / 100ml or more (1st tea extract) and high concentration of catechin polymer with 50% or more of catechin polymer relative to the total amount of catechin A food or drink comprising an extract (second tea extract). 16. The content ratio of the first or first 'tea extract and the second or second' tea extract is 9: 1 to 2: 8, according to any one of claims 12 to 15. Food and drink according to item. The food and drink according to claim 16, which is a oolong tea beverage.