JP2011160715A - Mulberry tea leaf and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide mulberry tea leaves from which mulberry tea excellent in color, taste (sweetness), astringency and freshness can be extracted. <P>SOLUTION: The mulberry tea leaves have at least 3.0 wt.% of tannin, and is produced from new buds whose leaf blades each have the length from the base to the tip end corresponding to 10-50% of the length from the base to the tip end of the leaf blade of a grown-up raw leaf. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to mulberry tea leaves and a method for producing the same.

As mulberry tea leaves, tea leaves produced from raw mulberry leaves are known. Mulberry tea extracted from mulberry tea leaves is effective for the prevention and treatment of diabetes, constipation, hypertension and the like, so mulberry tea is widely popular as a health drink.
On the other hand, when comparing mulberry tea leaves and green tea leaves, mulberry tea leaves have a high proportion of veins and are yellowish, and the extract mulberry tea has a light brown color. Mulberry tea, like green tea, is easily browned by oxidation. Furthermore, mulberry tea has a scent and sweetness peculiar to mulberry, but lacks the depth of taste like green tea, and therefore, the taste tends to be easily separated in the flavor.
Therefore, development of mulberry tea that has improved these points is desired.

  This invention makes it a subject to provide the mulberry tea leaf which can extract the mulberry tea excellent in a color, umami (sweetness), a splash, and refreshing.

  The present inventors have conducted intensive studies in view of the above problems. As a result, it was found that by using mulberry shoots as a raw material, mulberry tea leaves exhibiting a green color like green tea leaves can be produced. Furthermore, it has been found that the extract of the mulberry tea leaves is excellent in umami (sweetness), splashing and refreshing, and has little color change due to oxidation. The present invention has been made based on these findings.

That is, the present invention is a mulberry tea leaf containing at least 3.0% by weight of tannin, and the length from the root to the tip of the leaf is 10 times the length from the root to the tip of the mature fresh leaf. Mulberry tea leaves produced from shoots that are ˜50% long are provided.
The present invention also relates to a method for producing a mulberry tea leaf containing at least 3.0% by weight of tannin, comprising at least a steaming step and a rough koji step, wherein the leaf leaves have a mature length from the root to the tip. Provided is a production method using a sprout that is 10 to 50% of the length from the root of the leaf blade to the tip.

According to the present invention, there is provided a mulberry tea leaf that can extract mulberry tea that has a green color similar to green tea and is excellent in splashing, umami (sweetness), and refreshing, and is closer to the taste of green tea. Mulberry tea extracted from the mulberry tea leaves of the present invention has little color change over time due to oxidation.
According to the present invention, a method for producing the mulberry tea leaves is provided.

1. Mulberry tea leaf of the present invention (i) Mulberry sprout according to the present invention In the present invention, "mulberry sprout" means a side bud grown from a mulberry branch and does not include a top bud grown from the tip of the branch. In the mulberry shoot used in the present invention, the length from the root to the tip of the leaf blade in the shoot is 10 to 50% of the length from the root to the tip of the mature leaf in the same individual. Preferably, the length is 10 to 45%, more preferably 15 to 35%, and still more preferably 15 to 35%. Further, the shoots of mulberry used in the present invention are shoots that have passed from 5 to 30 days after the shoots have sprouted, and are preferably shoots that have passed from 7 to 25 days since the shoots have sprouted. It is more preferable that the shoot is 10 to 20 days after the germination. If the shoots are too small, the color of the mulberry tea leaves produced from the shoots will be brown, and it will not be possible to extract mulberry tea that is green like green tea. On the other hand, if the sprout is too large, the difference from the conventional mulberry tea leaf produced from fresh leaves cannot be obtained. In the present invention, “live leaves” means leaves further grown from the shoots used in the present invention.

The “length from the base of the leaf blade to the tip” means a linear distance between the border between the leaf blade and the petiole and the tip of the leaf blade farthest from the border. The linear distance is measured with the leaf blades placed horizontally.
The “mature fresh leaves” mean fresh leaves grown to a maximum size. In the present invention, “length from root to tip of leaf blade in mature fresh leaf” is an average value of the length from root to tip of leaf blade of ten mature fresh leaves grown from the same individual.
The above-mentioned “bud germination” means that winter buds attached to branches that grew in the previous year change from brown to green and the first leaves emerge from the buds.

  Mulberry sprouts can be efficiently induced by pruning mulberry by a predetermined method. For example, in the mulberry that induced the pupae by not pinching for a certain period of time, among the branches that branch off from the pupae and extended, the branch having a cross-sectional diameter less than a predetermined length at the root portion is excised from the root, Further, among the branches that branch off from the long branch, the branch having a cross-sectional diameter of the root portion having a length greater than or equal to the predetermined length has a method of cutting a portion having a cross-sectional diameter less than the predetermined length. Can be mentioned. In this way, after a predetermined period of time has elapsed since pruning, shoots are efficiently induced on the branches that branch off from the long branches.

The “pinching” means a pruning method in which the tip of a growing branch is cut off and the extension of the branch is stopped.
The “long branch” means a branch grown to a length of about 2 to 4 m.
The “cross-sectional diameter” means the longest diameter in a cut surface cut perpendicular to the extending direction of the branches. The longest diameter can be determined by observing the branch from the outside. The “predetermined length” can be appropriately determined in consideration of varieties of mulberry and individual differences, but it is usually preferable that the length be between 1.2 cm and 1.8 cm. More preferably, the length is between 1.7 cm and 1.7 cm. When the mulberry from which the shoots are collected is Soiki, the “predetermined length” is preferably about 1.5 cm.

  In the case of mulberry cultivated in Japan, pruning the branches that branch off from the long branches is carried out in February, so that the mulberry tea leaves of the present invention can be obtained from late April to early May of the same year. A large amount of shoots as raw materials can be collected.

  The method for collecting shoots of mulberry is not particularly limited. For example, the shoots can be collected by cutting the branches with the shoots from the roots and squeezing them manually from the tips of the branches in the root direction.

  In the above pruning method, shoots are collected from branches that have been branched and grown from the primate branches, so that shoots that have been germinated directly from the pupae can be grown to fresh leaves. That is, the pruning method has an excellent advantage of enabling efficient collection of both shoots and fresh leaves in one season from one mulberry solid.

  In the present invention, the variety of mulberry from which shoots are harvested is not particularly limited, and may be a wild species or a variety produced by artificially crossing different mulberry varieties. Examples of such varieties include improved turnover, Ichinose, Aozumizumi, Soiki, etc., but Soiki can be suitably used. Soki is a variety registered under the Ministry of Agriculture, Forestry and Fisheries Variety Registration No. 16963. Soiki has a high elongation ability, so many shoots can be obtained, and high-quality mulberry shoots can be obtained in large quantities.

(Ii) Ingredients of Mulberry Tea Leaf of the Present Invention The mulberry tea leaf of the present invention is excellent in splashing, umami (sweetness) and refreshing. Here, “shibumi” is synonymous with bitterness and means one of the tastes mainly derived from tannins, and “umami” is one of the tastes derived from amino acids such as theanine and sugars. The “freshness” is a sensation derived from the aroma component, and has a meaning close to refreshing. In general, the taste of tea is evaluated based on splash, umami (sweetness), and freshness. These are mainly the contents and content of tannin, theanine and caffeine contained in tea, and the aroma contained in tea. Depends on the amount and balance of the ingredients. The mulberry tea leaves of the present invention contain tannin, caffeine and theanine in a well-balanced manner, and also have an abundant refreshing mulberry aroma, so that the mulberry has a so-called deep taste like green tea. Tea can be extracted.

  The amount of tannin contained in the mulberry tea leaves of the present invention is not particularly limited, but is preferably at least 3.0% by weight, more preferably at least 4.0% by weight, and at least 5.0% by weight. More preferably it is. Moreover, although there is no restriction | limiting in particular about the upper limit of the quantity of tannin contained in a mulberry tea leaf, Usually, it is 10.0 weight% or less.

  The amount of caffeine contained in the mulberry tea leaves of the present invention is not particularly limited, but is preferably at least 0.6% by weight, more preferably at least 0.8% by weight, and at least 1.0% by weight. More preferably. Moreover, although there is no restriction | limiting in particular about the upper limit of the quantity of caffeine contained in a mulberry tea leaf, Usually, it is 3.0 weight% or less.

  The amount of theanine contained in the mulberry tea leaves of the present invention is not particularly limited, but is preferably at least 2.5% by weight, more preferably at least 3.0% by weight. Moreover, there is no restriction | limiting in particular about the upper limit of the quantity of theanine contained in a mulberry tea leaf, Usually, it is 7.0 weight% or less.

  The mulberry tea leaves of the present invention further contain abundant vitamin C. The amount of vitamin C contained in the mulberry tea leaves of the present invention (the total amount of ascorbic acid and its salts) is not particularly limited, but is preferably at least 0.3% by weight, and preferably at least 0.5% by weight. More preferred. Moreover, although there is no restriction | limiting in particular about the upper limit of the quantity of vitamin C contained in a mulberry tea leaf, Usually, it is 1.0 weight% or less.

(Iii) Color of Mulberry Tea Leaf of the Present Invention The mulberry tea leaf of the present invention has a darker green color than conventional mulberry tea leaves produced from raw mulberry leaves, and exhibits a dark green color equivalent to green tea leaves. Furthermore, the mulberry tea extracted from the mulberry tea leaves of the present invention has little color change with time due to oxidation, and can keep the fresh color for a long time. This is considered to be partly due to the large amount of antioxidant components such as tannin and vitamin C contained in the mulberry tea leaves of the present invention. The color of tea, that is, the appearance, is an important factor that stimulates the desire to drink (hereinafter sometimes referred to as drinking), so the mulberry tea leaves of the present invention are not limited to conventional mulberry tea leaves, Compared to green tea leaves, it has excellent effects.

(2) Mulberry Tea Leaf Production Method of the Present Invention The mulberry tea leaf production method of the present invention is a production method using mulberry shoots as a raw material, and includes at least a steaming step and a rough koji step.

The “steaming process” is a process for inactivating the enzymes of the shoots by steaming the collected mulberry shoots with steam, and at the same time a process for imparting flexibility to the shoots But there is. There is no restriction | limiting in particular in the conditions of a steaming process, A normal condition can be employ | adopted. Such conditions include, for example, conditions of a steam temperature of about 70 to 110 ° C. for a few seconds to a few minutes, preferably a steam temperature of about 80 to 100 ° C. for a time of about 30 seconds to 200 seconds, more preferably 80 Conditions of about 60 seconds to 120 seconds at a vapor temperature of about 100 ° C. can be employed.
The equipment used for the steaming process can also be an ordinary equipment, for example, a zonal steamer (manufactured by Kawasaki Kiko Co., Ltd.).
Sprouts collected from mulberry are usually subjected to a steaming process after being washed.

The “constitution process” is a process in which the moisture of tea leaves is uniformly and efficiently evaporated by applying hot pressure to the mulberry shoots that have undergone the steaming process and stirring. There are no particular limitations on the conditions for the stake process, and normal conditions can be employed. Such conditions include, for example, conditions of about 20 minutes to 80 minutes at a temperature in the twisting machine of 50 to 100 ° C., preferably about 40 minutes to 70 minutes at a temperature of the inside of the twisting machine of about 60 to 90 ° C. Preferably, conditions of about 50 to 70 minutes can be employed at a temperature in the twisting machine of about 60 to 80 ° C.
The equipment used for the leasing process can also be an ordinary equipment, for example, a roughing machine (manufactured by Kawasaki Kiko Co., Ltd.).
The sample after the steaming step may be directly subjected to the roughing step, or may be subjected to the roughing step after being cooled.

  In general, when producing mulberry tea leaves from raw mulberry leaves, a process of cutting the raw mulberry leaves before the steaming process is required. On the other hand, in the production method of the present invention, since the shoots of mulberry which is a raw material are small and soft, it is not necessary to perform a step of cutting the shoots before the steaming step. That is, in the production method of the present invention, mulberry shoots can be subjected to a steaming step without cutting.

  The production method of the present invention may further include steps that can usually be included in the production of tea leaves, such as a twisting step, an intermediate brewing step, a brewing step, and a drying step.

  In the method for producing mulberry tea leaves of the present invention, mulberry shoots as raw materials are the same as the mulberry shoots described in (i) above, which can be obtained by the method described in (i) above. The mulberry varieties from which the mulberry shoots as raw materials are harvested are the same as the mulberry varieties described in (i) above.

  By the method for producing mulberry tea leaves of the present invention, at least 3.0% by weight of tannin that can extract mulberry tea that has a green color equivalent to that of green tea and that is excellent in umami (sweetness), splashing, and refreshing, and that is closer to the taste of green tea. Can be provided. In addition, according to the method for producing mulberry tea leaves of the present invention, it is possible to provide tea that has little color change with time and can continuously stimulate appetite.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these, unless the summary is exceeded.

Preparation Example 1 Collection of mulberry shoots Pruning mulberry About 200 Soiki (Ministry of Agriculture, Forestry and Fisheries Variety Registration No. 16963, Age 3-5 years) cultivated in a field in Umetsubo-cho, Hachioji City, February 12-13, 2009 Pruning was performed. Specifically, in the buds that were guided without pinching in the previous year, all the branches having a diameter of less than about 1.5 cm in the root portion of the branches branched from the buds were excised and branched from the buds. In a branch having a cross-sectional diameter of about 1.5 cm or more at the root portion of the branch, a portion having a cross-sectional diameter of less than about 1.5 cm was cut off.

2. Collection of mulberry sprouts Around May of the same year, sprouts that had been pruned in 1 above had sprouts that grew to about 10 to 15 cm on the branches branched from the long branches. From April 20 to 27, branches with the shoots were cut from the roots, and shoots that had grown to about 10 to 15 cm were collected by scrubbing from the tips of the branches in the direction of the roots. The total weight of the collected shoots was about 30 kg.

Preparation Example 2 Production of Mulberry Tea Leaves Using Mulberry Sprouts as Raw Materials After washing 3 kg of mulberry shoots collected in Preparation Example 1, the mulberry shoots were put into a zonal steamer (manufactured by Kawasaki Kiko Co., Ltd.) Steamed for ~ 100 seconds. Subsequently, the mixture was put into a coarse koji machine (manufactured by Kawasaki Kiko Co., Ltd.) and subjected to a coarse koji process by twisting at an in-machine temperature of 65 ° C. for 50 to 60 minutes to obtain 600 g of mulberry tea leaves.

Comparative Preparation Example 1 Collection of Fresh Mulberry Leaves In the splendor from which shoots were collected in Preparation Example 1, about 30 cm of fresh leaves were attached to the long branches around July of the same year. On July 16, 2009, the fresh leaves were removed from the roots and collected. The total weight of the collected fresh leaves was about 199 kg.

Comparative Preparation Example 2 Production of Mulberry Tea Leaves Using Raw Mulberry Leaves After washing 199 kg of mulberry fresh leaves collected in Comparative Preparation Example 1, the mulberry leaves were put into a cutting machine (manufactured by Kawasaki Kiko Co., Ltd.) and cut to about 5 cm ^2. This was put into a band-type steamer (manufactured by Kawasaki Kiko Co., Ltd.) and steamed for 160 seconds with steam at 100 ° C. and subjected to a steaming process. Subsequently, the mixture was put into a coarse koji machine (manufactured by Kawasaki Kiko Co., Ltd.) and twisted at an in-machine temperature of 90 ° C. for 50 minutes to be subjected to a coarse koji process to obtain 40.5 kg of mulberry tea leaves.

Test Example 1 Comparison of properties of mulberry tea leaves made from mulberry sprouts and mulberry tea leaves made from raw mulberry leaves About mulberry tea leaves in Preparation Example 2 and mulberry tea leaves in Comparative Preparation Example 2, the shape, color and content of mulberry tea leaves The components (tannin, caffeine, theanine and vitamin C) and the color of the extract (mulberry tea) and their changes over time were compared and evaluated. The extract of mulberry tea leaves used for the evaluation was prepared by pouring 100 mL of 98 ° C. hot water into 1 g of tea leaves, letting it stand for 60 seconds, and passing it through a tea strainer. The shape and color of tea leaves and the color of the extract were evaluated by visual observation. The content of tea leaves is measured using a tea component analyzer GT-8 (manufactured by Shizuoka Seisakusho Co., Ltd.) after the tea is ground using a crusher CSM-F1 (manufactured by Fujiwara Seisakusho Co., Ltd.). Determined by automatic measurement. The results are shown in Table 1.

  From the results of Table 1, the mulberry tea leaves of the present invention have a green color like green tea compared to the conventional mulberry leaves produced from mulberry leaves, and contain abundantly balanced tannin, caffeine, theanine and vitamin C. I understand that. Further, it was found that the mulberry tea leaf extract of the present invention hardly changes to brown color by oxidation.

Test Example 2 Sensory Evaluation of Mulberry Tea Leaves Made from Mulberry Sprouts and Mulberry Tea Leaves Made from Mulberry Raw Leaves About Mulberry Tea Leaves from Preparation Example 2 and Mulberry Tea Leaves from Comparative Preparation Example 2 The taste was sensory-evaluated by 32 panelists, and each level was scored from 0 to 3 points based on sensory evaluation items (five sense test) used in general green tea.
The tea color shows visual appetite stimulation of tea, 0 points when the color is bad and does not stimulate appetite at all, 3 points when it is very clean green and stimulates appetite quite strongly It was.
Regarding the aroma of tea, 0 points were given when no refreshing feeling was felt, and 3 points were given when the refreshing feeling was felt quite strongly.
For the tea splash, 0 points were given when no splash was felt, and 3 points were given when the splash was felt quite strongly.
The overall evaluation was based on a comprehensive evaluation of the tea's color, aroma, splashing, etc., with 0 points indicating that it was not delicious at all and 3 points indicating that it was very delicious.
The mulberry tea leaf extract used for the evaluation was prepared in the same manner as in Test Example 1.
Table 2 shows the average score based on the sensory evaluation.

The results in Table 2 show that the mulberry tea leaf extract of the present invention is superior in tea color and aroma as compared to conventional mulberry tea leaf extract produced from raw mulberry leaves.
In addition, in the mulberry tea leaf extract of Comparative Preparation Example 2, sweetness is stronger and almost no smoldering is felt, whereas in the mulberry tea leaf extract of Preparation Example 2, in addition to sweetness, smoldering is also felt strongly. . That is, it was shown that the extract of mulberry tea leaves of the present invention has abundant scum necessary for deep taste like green tea.
The overall evaluation of the mulberry tea leaf extract of Preparation Example 2 was very high, indicating that the mulberry tea leaf extract of the present invention was excellent as a tea beverage.

Claims (9)

Mulberry tea leaves containing at least 3.0% by weight of tannin,
Mulberry tea leaf produced from shoots whose length from the root to the tip of the leaf blade is 10-50% of the length from the root to the tip of the mature raw leaf.   2. Mulberry tea leaf according to claim 1, containing at least 0.8% by weight of caffeine.   The mulberry tea leaf according to claim 1 or 2, further comprising theanine and vitamin C. A first step of guiding the primate branch,
In order to select a branch to be pruned from the branches branched from the long branch, the diameter of the cross section at the root portion of the branch is determined to be any length between 1.2 cm and 1.8 cm. 2 steps, and a branch having a diameter shorter than the length determined in the second step is cut from the root of the branch branched from the long branch, and a cross section at the root of the branch branched from the long branch In a branch having a diameter equal to or larger than the length determined in the second step, a third step of cutting a portion whose cross-sectional diameter is shorter than the length determined in the second step;
The mulberry tea leaf as described in any one of Claims 1-3 which uses the sprout extract | collected from the mulberry pruned by the method containing this as a raw material.   The mulberry tea leaf according to any one of claims 1 to 4, wherein the mulberry cultivar is Soiki (Ministry of Agriculture, Forestry and Fisheries, Variety Registration No. 16963). A method for producing mulberry tea leaves containing at least 3.0% by weight of tannin, comprising at least a steaming step and a crude koji step,
A production method using, as a raw material, a sprout whose length from the root to the tip of a leaf blade is 10 to 50% of the length from the root to the tip of a mature raw leaf.   The production method according to claim 6, wherein the mulberry shoots are subjected to a steaming step without cutting. A first step of guiding the primate branch,
In order to select a branch to be pruned from the branches branched from the long branch, the diameter of the cross section at the root portion of the branch is determined to be any length between 1.2 cm and 1.8 cm. 2 steps, and a branch having a diameter shorter than the length determined in the second step is cut from the root of the branch branched from the long branch, and a cross section at the root of the branch branched from the long branch In a branch having a diameter equal to or larger than the length determined in the second step, a third step of cutting a portion whose cross-sectional diameter is shorter than the length determined in the second step;
The manufacturing method of Claim 6 or 7 which uses the sprout extract | collected from the mulberry pruned by the method containing this as a raw material.   The manufacturing method as described in any one of Claims 6-8 whose varieties of a mulberry are Soki (Ministry of Agriculture, Forestry and Fisheries kind registration number 16963).