JP5951998B2 - Chafloside A high content tea leaves and method for producing the same - Google Patents

Description

  The present invention relates to a method for producing a tea leaf for beverages having an increased content of chafloside A, and more particularly to a method of burning that significantly increases the content of chafloside A.

  Chafuroside is an active ingredient contained in a trace amount in tea leaves such as oolong tea, green tea, roasted tea, and black tea. It is classified into flavone C glycosides which are a kind of flavone derivative, and chafloside A (formula (1)) and chafloside B have been identified to date (Patent Document 1).

  Anti-allergic action (Patent Document 1), carcinogenesis-inhibiting action (Patent Document 2), and the like are known as effects of chafloside. In particular, chafloside A has been reported to have a significant inhibitory effect on the formation of chemical-induced aberrant cryptoforsy (ACF, a type of precancerous colorectal cancer lesion) and intestinal polyp formation in colorectal cancer model mice ( Patent document 2), the expectation as a pharmaceutical ingredient is increasing.

  However, the Chafloside A content of tea leaves by HPLC analysis of the tea leaf extract is very low, 24.8 μg / g (tea leaves) for the highest oolong tea, 80 ng / g (tea leaves) for green tea, 4 μg / g (tea leaves) for roast tea, It is about 80 ng / g (tea leaves) for black tea (Patent Document 2). Therefore, since it is difficult to purify chafuroside A from tea leaves, in recent years, isovitexin (isovitexin, formula (2)) is sulfated, and chafuroside A is produced from sulfated isovitexin 2 ″ (isovitexin2 ″ -sulfate, formula (3)). A method was reported (FIG. 1, Patent Documents 3 and 4). However, since the chemical production method requires expensive or dangerous chemicals, it is strongly desired to increase the content of chafuroside A in the tea beverage by a safe and economical method.

  As such an attempt, Patent Document 2 reports that the chafloside content is increased by heat-treating tea leaves at 180 ° C. or higher. However, it has also been reported that when heat treatment at 180 ° C. or higher is performed, most of the chafuroside in the tea leaves is thermally decomposed (Patent Document 5). Therefore, Patent Document 5 discloses that the chafloside content in the dried tea leaves can be increased by heat-treating the dried tea leaves at 115 to 125 ° C for 100 to 350 minutes, or 125 to 150 ° C for 10 to 240 minutes. doing. However, the long-time treatment as described above is not preferable as an industrial production method for tea leaves for beverages.

  In the process of manufacturing tea leaves for beverages, heat treatment of crude tea (= dried tea leaves that have undergone various processes and can be stored for a long period of time) immediately prior to shipment for the purpose of improving the flavor of tea leaves and tea beverages (= heating process) )I do. Therefore, it would be advantageous if the chafloside content can be increased by heat treating the tea leaves. However, since tea leaves generally deteriorate in quality as a tea beverage when exposed to a high temperature for a long time, the temperature and heating time of the tea leaves in the above-described firing process must be minimized. However, the tea temperature in the firing process is strongly influenced not only by the temperature of the heating container but also by various factors (vapor pressure derived from moisture contained in the tea leaves, the amount of tea leaves input, and / or the capacity of the heating containers, etc.). To receive it, there was hardly ever been grasped.

JP 2004-035474 A JP 2006-342103 A JP 2005-289888 A WO2010 / 0776879 WO2009 / 057556

  Thus, high-temperature heat treatment is effective for increasing the content of chafuroside in tea leaves, but in order to avoid thermal degradation of chafroside and quality deterioration of tea beverages, the heating conditions (heating temperature and heating time) of tea leaves Must be kept within the proper range. However, the shorter the tea leaf heating time is set to avoid the above thermal decomposition and quality deterioration, the more the tea temperature reaches the equilibrium state, the more the heating process is completed. There was a problem of becoming unknown. For this reason, the reproducibility of the heating conditions in the heat treatment is very low, and the chafloside A content contained in the tea leaves after the heat treatment is not stable, so that it is considered that the industrialization of the heating step is difficult.

  In order to solve the above-mentioned problems, the present inventors have determined the heating conditions of tea leaves by tea temperature and intensively studied the conditions. As a result, isovitexin and / or sulfated isovitexin 2 ″ that is a chafuroside A precursor in tea leaves, It was found that the temperature conditions for increasing chafuroside A were different. When heat treatment suitable for increasing chafuroside A was performed after heat treatment for selectively increasing isovitexin and / or sulfated isovitexin 2 ″, sulfated isovitexin 2 It is found that the conversion from "to chafloside A efficiently occurs, and as a result, tea leaves having a significantly increased content of chafloside A are obtained, and at the same time, the quality as tea leaves for beverages is improved, and the present invention is completed. Furthermore, the heating process was performed while adding a steam-containing gas heated to 140 to 280 ° C. Doing, is also found that the quality of tea beverage extracted from tea leaves through the process is further improved.

  That is, the present invention is a method for producing tea leaves for beverages by putting dry tea leaves having a water content in the range of 1 to 10% by mass into a heated heating container and heating the tea leaves while stirring. The content of isovitexin and / or sulfated isovitexin 2 ″ is characterized in that the temperature of the tea leaves in the heating step is maintained in the range of 115 to 170 ° C. for 1 minute 30 seconds to 4 minutes 30 seconds. A method for producing increased tea leaves for beverages is provided.

  In the method for producing beverage tea leaves in which the content of isovitexin and / or sulfated isovitexin 2 ″ is increased, the heating container is divided into two or more sections, and each heating section can be maintained at the same or different temperature. And the tea leaves have the same temperature or higher temperature as they move between the compartments.

  The present invention is also a method for producing tea leaves for beverages, wherein tea leaves having increased content of isovitexin and / or sulfated isovitexin 2 ″ through the heating step are heated while being stirred in a heated heating container. In the heating step, the tea leaf temperature is maintained in the range of 171 to 205 ° C for 1 to 3 minutes, or higher than 205 ° C to 240 ° C for 15 to 30 seconds. A method for producing tea leaves for beverages having an increased amount is provided.

  In the method for producing a tea leaf for beverages with an increased content of the chafloside A, the heating container is divided into two or more sections, each heating section is a heating container that can be maintained at the same or different temperature, and the tea leaves are The temperature is the same or higher as it moves between the compartments.

  In the method for producing tea leaves for beverages having an increased content of isovitexin and / or sulfated vitexin 2 ″ or chafuroside A, a steam-containing gas heated to a temperature in the range of 240 to 280 ° C. is further added to the heating container. Provided is a method for producing beverage tea leaves, wherein the heating step is performed while blowing.

  A method for producing a tea leaf for beverage, wherein the content of isovitexin and / or sulfated vitexin 2 "or chaflocide A is increased, wherein the dried tea leaf is a dried tea leaf of a non-fermented tea leaf. provide.

  A method for producing a tea leaf for beverage, wherein the content of the isovitexin and / or sulfated vitexin 2 "or chafuroside A is increased, wherein the dried tea leaf is a dry tea leaf of a semi-fermented tea leaf. provide.

  Provided is a method for producing tea leaves for beverages wherein the content of isovitexin and / or sulfated vitexin 2 "or chafuroside A is increased, wherein the dried tea leaves are dried tea leaves obtained by fermentation. To do.

  Furthermore, this invention provides the tea leaf for drinks with a high content of chafloside A characterized by containing 40 micrograms or more of chafloside A per 1 g of dry tea leaves.

  By using the production method of the present invention, it is possible to safely, economically and simply produce tea leaves in which the content of chafuroside A having various beneficial physiological activities is greatly increased (several times to several hundred times). it can. This production method can be used for various tea leaves (for green tea, for oolong tea, for tea, roasted tea, etc.), and for tea beverages extracted from the tea leaves produced by this method, quality (appearance, light blue color, aroma, It also has excellent taste. The production method of the present invention is highly reproducible because the heating temperature of tea leaves is specified by the tea temperature, and thus the industrialization of the production process is easy.

It is the figure which showed the synthetic | combination path | route of the chafloside A. It is the result of having measured the time-dependent change of the tea temperature of the tea leaf after throwing into a heating container with a radiation thermometer (A) and / or thermography (B).

  The method for producing a tea leaf for beverage of the present invention will be described by taking tea leaf for green tea as an example, but the present invention is not limited to the tea leaf for green tea. By using the production method of the present invention for tea leaves for oolong tea, black tea, and roasted tea, tea leaves having a significantly increased content of chafuroside A can be produced.

Tea leaf The dry tea leaf used in the present invention has a water content in the range of 1 to 10% by mass. In the present invention, the moisture content of the dried tea leaves is a value calculated using the following formula from the mass before heating and the mass after heating when the tea leaves are heated at a temperature of 105 ° C. for 5 hours.
Moisture content (mass%) = 100 × (mass before heating−mass after heating) / mass before heating As the types of tea leaves that can be used in the present invention, green tea that is unfermented tea and tea leaves for roasted tea (for example, Karabe nicha, Yabukita tea, etc.), tea leaves for oolong tea that are semi-fermented tea (for example, Wuyi narcissus, Daffodil, narcissus, etc.) Is preferred.

  For the dried tea leaves, rough tea and green tea products (finished tea) can be used. In general, rough tea is a process of steaming fresh tea leaves that have been picked (process of steaming fresh tea leaves with steam to inactivate the enzymes in the fresh tea leaves), and rough rice cake process (blowing hot air on the tea leaves after the steaming process) Process to soften the tea leaves by applying pressure and friction), twisting process (pressing the tea leaves while rolling them to make the whole tea leaves even), middle-boiled process (wiping hot air on the tea leaves, The process of applying pressure to make the tea leaves twisted), the brewing process (heating the tea leaves, applying pressure to the tea leaves to shape and tighten the tea leaves), the drying process (drying the tea leaves) To be manufactured through each of the steps. Green tea products are used for tea leaves for beverages by performing processes such as the process of burning crude tea (process for improving the flavor by heating the crude tea) and the selection process (process for removing stems and fine tea leaves from the crude tea). It means the one with improved quality. The crude tea and green tea products may be used as dry tea leaves as they are, or may be used as shredded products that have been crushed by a crusher and adjusted to a size of 3 to 10 mm. In the embodiment of the present application, a thin cut material (cut No. 7) cut so as to pass through a sieve having a diameter of about 4.2 mm was mainly used.

Dried tea leaves vary depending on the type of tea leaves, the region where they are collected, and the season, but usually 10 to 10 micrograms of chaflocide A (formula 4) per gram of tea leaves, the precursor isovitexin (formula 5) And sulfated isovitexin 2 "(formula 6) in the range of several tens to several hundreds of micrograms and several micrograms to several tens of micrograms, respectively. Beverages having an increased content of chafuroside A according to the present invention The manufacturing method for tea leaves is the sulfated isovitexin 2 ”that dry tea leaves originally have
And it can be used regardless of the content of chafloside A.

Heating vessel The heating vessel that can be used in the present invention may be a heating vessel that is generally used in the process of burning tea leaves, but the heating compartment has two or more heating sections so that the multistage heating treatment can be performed with one heating vessel. It is preferable to have a temperature control function that is divided into compartments and that is independent for each compartment. However, in the multi-stage heat treatment according to the present invention, there is no necessity to continuously perform each heating step, and an interval of several hours to several months can be provided between each heating step. May be a heating device having only one section.
The heating container used in the present invention needs to have a function to keep stirring tea leaves efficiently so that the temperature of the tea leaves quickly becomes homogeneous in each heating section. If the cylindrical container is preferably placed horizontally, and the protrusions or grooves are spirally provided on the inner wall surface, the tea leaves are efficiently stirred as the container rotates. As an example of such a heating container, there is an IH fired machine (FR100K-1, manufactured by Kawasaki Kiko Co., Ltd.) used in the present invention. The IH wound around the fuselage is divided into three parts, and three types of temperatures can be set for each heating section.

  The heating container used in the present invention is a tea leaf feeder for continuously supplying tea leaves to the heating container (for example, a tea leaf feeder, manufactured by Kawasaki Kiko Co., Ltd.), or a steam containing gas. Devices (for example, Super Steamer, Kawasaki Kiko Co., Ltd.) may be combined. In the present invention, when the tea leaves are fed using the tea leaf feeder, and the steam-containing gas is blown into the heating container, the super steamer is used. The water vapor-containing gas used in the present invention is preferably heated water vapor or water vapor-containing gas. The water vapor-containing gas preferably has a water vapor amount of 50 g / h (hour) or more, and more preferably 80 g / h or more. The amount of steam-containing gas blown into the heating vessel varies depending on conditions such as the capacity and temperature of the heating vessel, but the amount of water vapor is preferably in the range of 10 to 100 g / h, and most preferably 50 g / h. .

The temperature of the tea leaves in the tea temperature measurement heating container is preferably measured in a short time using a non-contact thermometer such as a radiation thermometer or thermography, considering that the measurement object (tea leaves) is moving at high speed. . In the present invention, a small window is provided at the outlet of the heating container (IH firer, FR100K-1, manufactured by Kawasaki Kiko Co., Ltd.) so that the internal temperature hardly changes by opening and closing. Then, the small window is opened quickly, and the temperature of the tea leaf in the portion corresponding to 80% of the total groove length (from the tea leaf inlet) of the groove provided on the inner wall of the heating cylindrical container is set in contact with the window. The measurement was performed in an extremely short time using a radiation thermometer or a camera for thermography.

Heating conditions In the present invention, the heating temperature suitable for selectively increasing isovitexin and / or sulfated isovitexin 2 ″, which is a chafuroside A precursor, in the tea leaves is a tea temperature in the range of 115 to 170 ° C., The heating time is preferably 115 to 165 ° C., most preferably 120 to 160 ° C. The heating time at tea temperature suitable for increasing isovitexin and / or sulfated isovitexin 2 ″ is 1 minute 30 seconds to 4 minutes 30 Seconds are preferred, more preferably 2 to 4 minutes. The heating temperature for efficiently converting sulfated isovitexin 2 ″ to chafuroside A is a tea temperature of 171 to 205 ° C., more preferably 175 to 200 ° C., most preferably 180 to 200 ° C. 3 minutes, more preferably 1 minute 30 seconds to 2 minutes 30 seconds, most preferably 1 minute 30 seconds to 2 minutes, or tea temperature higher than 205 ° C to 240 ° C, more preferably 210 to 235 ° C The heat treatment is most preferably in the range of 215 to 230 ° C. for 15 to 30 seconds, and more preferably 20 to 30 seconds.
Then, after the heat treatment for selectively increasing the isovitexin and / or sulfated isovitexin 2 ″, the heat treatment for promoting the conversion of the sulfated isovitexin 2 ″ to chafuroside A is carried out, thereby containing chafuroside A. Tea leaves whose amount is increased several to several hundred times can be produced. The amount of chaflocide A in the dried tea leaves obtained according to the present invention does not fall below 40 μg per 1 g of dried tea leaves.

  The multi-stage heat treatment is not only effective for increasing the Chafloside A content of tea leaves, but is also beneficial for improving the quality of tea beverages extracted from tea leaves. This is because the tea beverage extracted from the tea leaves subjected to the multi-stage heat treatment of the present invention is superior in flavor to the tea leaves subjected to the one-stage heat treatment. Furthermore, when the multistage heat treatment is performed while blowing the heated steam-containing gas into the heating container, the quality of the tea beverage extracted from the tea leaves is further improved. The temperature of the water vapor-containing gas used for this purpose is preferably 240 to 280 ° C, more preferably 250 to 270 ° C, and most preferably 260 ° C.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

In Tables 3 to 14, sulfated isovitexin 2 ″ is expressed as PreChaA and chafuroside A is expressed as ChaA, and the unit of each content is μg / g (= mass of dried tea leaves). The unit of isovitexin is also μg. / G (= mass of dry tea leaves), and the unit of tea temperature is ° C.
In Tables 3 to 11, ** in the table is an example in which isovitexin and PreChaA are selectively increased and the increase in ChaA is not significant, and * is an example in which the conversion from PreChaA to ChaA is significantly promoted. Each is shown.

The analysis method used in the examples will be described.
As an equipment heating device, an IH burning machine (FR100K-1 (IH)) was used, and a tea leaf feeder and a super steamer (both manufactured by Kawasaki Kiko Co., Ltd.) were used as necessary. As described above, the heating device used in the present invention is provided with a small window for measuring tea temperature at a site corresponding to 80% of the total groove length (running length of tea leaves) when viewed from the tea leaf charging portion.

Tea temperature measurement As described above, the tea temperature of tea leaves after 80% of the total heating time was measured by inserting a radiation thermometer or a thermographic camera into a small window provided in the heating device. FIG. 2A shows a graph of the change over time in tea temperature measured with a radiation thermometer. Table 1 below shows the measurement results of both the radiation thermometer and the thermography for the total heating time, time to tea temperature measurement, tea temperature, and the like. Further, a graph of Table 1 is shown in FIG. 2B.

  Looking at the graph (Fig. 2A) measured with a radiation thermometer, the tea temperature rises quickly after the tea leaves are put into the heating vessel, but it is found that the state reaches an equilibrium state at a temperature lower than the set temperature of the heating vessel. . It can be seen that the tea temperature measured by thermography with higher accuracy than that of the radiation thermometer is even lower, reaching a nearly parallel state at a lower tea temperature (Table 1, FIG. 2B). There are various reasons why the tea temperature does not reach the set temperature of the heating container within the above heating time (within 20 minutes 48 seconds) (insufficient heating time, influence of water vapor from tea leaves, etc.) It was revealed that there was a difference of at least 16.9 to 19.5 ° C. between the set temperature of the container and the tea temperature (calculated from thermographic measurement values after 26 minutes). Therefore, it was shown that the heating temperature of tea leaves should be specified by the tea temperature, not the set temperature of the heating container.

  In view of the above results, in the present invention, a more accurate thermography is used for the tea temperature measurement. From the graph of FIG. 1B, the tea temperature measured by thermography can be estimated to be about 142 ° C. (180 ° C. setting) or about 152 ° C. (190 ° C. setting) two minutes after charging the heating container. When this value is compared with the tea temperature after 26 minutes (163.1 ° C at 180 ° C setting, 170.5 ° C at 190 ° C setting), the tea temperature after 2 minutes is the tea temperature after 26 minutes (= almost equilibrium state) ) About 87.1% (180 ° C. setting) or 89.4% (190 ° C. setting). When the same calculation is performed, the tea temperature 2 minutes after the heating vessel is charged is close to about 92.8% (set at 180 ° C.) to about 93.5% (set at 190 ° C.) of the tea temperature after 5 minutes and 12 seconds. Can be guessed as a value. In addition, the tea temperature 6 minutes 48 seconds after charging the heating container is estimated to be a value close to about 101.4% (180 ° C. setting) to about 101.6% (190 ° C. setting) of the tea temperature 5 minutes 12 seconds later. it can.

The tea leaves after the component analysis heating step were pulverized with a coffee mill to obtain tea leaf powder. 5 ml of 50% by mass methanol was added to 50 mg of the tea leaf powder, and stirring and extraction in a 80 ° C. hot water bath were performed for 30 minutes in a glass screw-mouth test tube together with a rotor. The extract (= tea leaf extract) was centrifuged (6200 rpm, 2 minutes) using a centrifuge (small microcentrifuge, PMC-060T, manufactured by TOMY), and 100 μl of the supernatant was used with 50% by mass of methanol. Then, 5 μl of the solution was quantitatively analyzed for isovitexin, sulfated isovitexin 2 ″, and chafuroside A using an HPLC-MS / MS apparatus.

  Agilent 1200SL (manufactured by Agilent Technologies) was used as the HPLC apparatus, Cadenza CD C18HT (inner diameter: 3 mm, length: 150 mm, manufactured by Intact) was used as the column, and API4000Q-TRAP (manufactured by AB SEX) was used as the MS apparatus. As a developing solution, A solution (0.1% formic acid) and B solution (100% by mass methanol) were used, and gradient elution was performed with the following settings.

Sensory evaluation A tea strainer was placed in a tea bowl, and 2 g of tea leaves after the heating process were put into the tea strainer, and 200 ml of hot water was poured from above. After leaving still for 3 minutes, the tea leaves were taken out after stirring about 10 times, and 4 to 8 panelists were allowed to drink the extracted tea beverages. The sensory evaluation of the tea beverages was performed by the following two methods.
(Evaluation 1) 4-8 panelists sampled the tea drinks, and received 1 point for the best quality and 0 points for the others. The total score of all members was evaluated.
(Evaluation 2) 4-8 panelists evaluated the appearance, color, aroma, and taste of the tea beverage in 0 to 3 points (0 points: inferior, 1 point: slightly inferior, 2 points: Usually, 3 points: good), an average score was calculated for each evaluation item. And the total score of all the evaluation items was made into comprehensive evaluation.

Example 1
The tea leaves for green tea were subjected to a heat treatment at a constant temperature, and the influence of the heating temperature on the content of isovitexin, sulfated isovitexin 2 ″ (PreChaA) and chafuroside A (ChaA) in tea leaves was analyzed. The heating container used is divided into three heating zones, so it is possible to set the temperature in three stages, but all three zones are set to the same temperature.The total heating time is 6 minutes 30 seconds, so the tea temperature measurement time is 5 After 12 minutes (see Table 1), the tea leaves used were dried tea leaves of green tea leaves 1 that had been subjected to cutting treatment No. 7. The results are shown in Table 3.
As described above, ** in the table is an example in which isovitexin and PreChaA are selectively increased without significantly increasing ChaA, and * is an example in which the conversion from PreChaA to ChaA is significantly promoted. Each example is shown.

  In tea leaves 1 for green tea subjected to No. 7 cutting treatment, selection of isovitexin and PreChaA in the example (**) in which the tea temperature at 12 minutes to 155.5 ° C. after 5 minutes and 12 seconds from the introduction of the heating container Increase was observed. On the other hand, a significant increase in ChaA was observed in the Examples (*) where the tea temperature was 172.2 to 186.9 ° C. Therefore, it is clear that the temperature at which the selective increase of isovitexin and / or PreChaA occurs in the dried tea leaves is different from the temperature at which the conversion from PreChaA to ChaA actively occurs, and the latter is higher. became.

  In order to increase the ChaA content in tea leaves, it is most effective to promote the conversion of PreChaA to ChaA after the PreChaA is sufficiently increased. Therefore, first, it was decided to determine heating conditions for selectively and effectively increasing isovitexin and / or PreChaA in tea leaves.

In Example 1, a selective increase in isovitexin and PreChaA was remarkably observed in tea leaves (**) having a tea temperature of 129.8 to 155.5 ° C. 5 minutes and 12 seconds after charging the heating container, but 5 minutes. In tea leaves having a tea temperature of 122.7 ° C. or lower or 172.2 ° C. or higher after 12 seconds, no selective increase in isovitexin and PreChaA was observed. From Table 1, it can be inferred that the tea temperature 2 minutes after charging the heating vessel was about 92.8-93.5% of the tea temperature 5 minutes 12 seconds later (paragraph [0039]), 5 minutes 12 seconds. It can be inferred that the tea temperatures after 2 minutes of the tea leaves that were later 122.7 ° C. and 129.8 ° C. were about 113.9 to 114.7 ° C. and 120.5 to 121.4 ° C., respectively. . Therefore, in order to cause a selective increase in isovitexin and / or PreChaA, it is considered necessary that the tea temperature after 2 minutes is higher than about 114.7 ° C., that is, 115 ° C. or higher.
Similarly, the tea temperature after 6 minutes and 48 seconds can be estimated to be about 101.4 to 101.6% of the tea temperature after 5 minutes and 12 seconds (Table 1), and the tea temperature after 5 minutes and 12 seconds is 155. The tea temperatures at the end of the heating time (after 6 minutes 30 seconds) of 5 ° C and 172.2 ° C were about 157.7 to 158.0 ° C and about 174.6 to 175.0 ° C (= It can be presumed that the temperature was lower than the tea temperature (assuming that it was heated up to 6 minutes 48 seconds). Therefore, in order to cause a selective increase in isovitexin and / or PreChaA, the tea temperature at the end of the heating step is lower than about 174.6 ° C., that is, 170 ° C. or less, more preferably 160 ° C. or less. It is considered necessary.
From the above, the heating conditions suitable for causing a selective increase in isovitexin and / or PreChaA with respect to the dried tea leaves of green tea leaves cut No. 7 are tea temperatures of 115 to 170 ° C., more preferably 115 to It can be said that heating is performed in the range of 160 ° C. for about 4 minutes and 30 seconds.

Example 2
Next, in order to investigate the influence by the difference in the cutting method of tea leaves, the tea leaves 1 for green tea used in Example 1 were cut by 3 mm, and the same analysis as in Example 1 was performed. The same method as in Example 1 was used except for the cutting mode of tea leaves.

As is apparent from Table 4, even when 3 mm cut dry tea leaves were used, the heating temperature (**) that caused a selective increase in isovitexin and PreChaA and the heating temperature that promoted the conversion from PreChaA to ChaA (*) ) Was different and the latter was shown to be hotter.
The selective increase in isovitexin and / or PreChaA is hardly observed in tea leaves having a tea temperature of 120.3 ° C. after 5 minutes and 12 seconds from the introduction of the heating container, and is remarkable in tea leaves having 127.4 ° C. The tea temperature after 2 minutes of the tea leaves after 12 minutes at 12 minutes and 127.4 degrees Celsius after 5 minutes and 12 seconds were about 111.6 to 112.5 degrees Celsius and about 118.2 to 119 respectively. It can be estimated that the temperature was 1 ° C. (Table 1). Therefore, in order to cause a selective increase in isovitexin and / or PreChaA for tea leaves 1 for green tea cut 3 mm, the tea temperature after 2 minutes is higher than about 112.5 ° C., that is, 115 ° C. or higher. It is considered necessary.
In addition, a selective increase in isovitexin and PreChaA is observed in tea leaves with a temperature of 156.4 ° C. 5 minutes and 12 seconds after charging in the heating container, but an increase in ChaA is significant in tea leaves at 169.3 ° C., so isovitexin And a selective increase in PreChaA. The tea temperatures at the end of the tea leaf heating time (after 6 minutes and 30 seconds) when the tea temperatures after 5 minutes and 12 seconds were 156.4 ° C. and 169.3 ° C. were about 158.6 to 158.9, respectively. It can be inferred that the temperature was lower than that at about 171.7 to 172.0 ° C. (= the tea temperature when heated up to 6 minutes 48 seconds) (Table 1). Therefore, in order to cause a selective increase in PreChaA, it is considered necessary that the tea temperature at the end of the heating step is lower than about 171.7 ° C., that is, 170 ° C. or less, more preferably 160 ° C. or less. .

  From the above, the heating conditions suitable for causing a selective increase of isovitexin and / or PreChaA for both tea leaves 1 for green tea subjected to No. 7 cutting and 3 mm cutting treatment are as follows: It can be said that the heating is preferably in the range of 115 to 160 ° C. for about 4 minutes and 30 seconds. Further, although omitted in the present application, it has been confirmed that the heating temperature for selectively increasing the PreChaA has little influence on the presence or absence of the cutting treatment. Therefore, it can be said that the heating method for selectively increasing the isovitexin and / or PreChaA of the present invention can be applied regardless of whether or not the tea leaves are cut and the cutting style is different.

Example 3
Next, the result using tea leaves for oolong tea is shown. The same analysis method as in Example 1 was used except that the types of tea leaves were different.

Even when tea leaves 1 for oolong tea are used, the tea temperature (**) suitable for the selective increase of isovitexin and PreChaA is different from the tea temperature (*) suitable for promoting the conversion from PreChaA to ChaA. It was shown to be hotter.
In Example 3, in tea leaves (**) having a temperature of 126.3 to 156.5 ° C. 5 minutes and 12 seconds after charging the heating container, a selective increase in isovitexin and PreChaA was significantly observed. No selective increase in PreChaA was observed in tea leaves having a temperature of 121.0 ° C. or lower, or 178.1 ° C. or higher. After 5 minutes and 12 seconds, the tea temperatures after 12 minutes of tea were 121.0 ° C and 126.3 ° C, respectively, were about 112.3 to 113.1 ° C and about 117.2 to 118.1 ° C, respectively. (Table 1). Therefore, in order to cause a selective increase in isovitexin and / or PreChaA, it is considered necessary that the tea temperature after 2 minutes is higher than about 113.1 ° C., that is, 115 ° C. or higher.
Similarly, the tea temperature at the end of the tea leaf heating time after 16 minutes at 15 minutes and 168.2 ° C. was about 164.9 to 165.2 ° C. and about 180.6 ° C., respectively. It can be presumed that the temperature was lower than ˜180.9 ° C. (= tea temperature when it was assumed to be heated up to 6 minutes 48 seconds). Therefore, in order for the selective increase in isovitexin and / or PreChaA to occur, the tea temperature at the end of the heating step needs to be lower than about 180.6 ° C., that is, 180 ° C. or lower, more preferably 170 ° C. or lower. it is conceivable that.

From the above, the heating conditions suitable for causing a selective increase in isovitexin and / or PreChaA with respect to the dried tea leaves of oolong tea leaves 1 are those in which the tea temperature is 115 to 180 ° C, more preferably 115 to 170 ° C. It can be said that it is heating for about 4 minutes 30 seconds.
Although omitted in the present application, when the dried tea leaves of other types of tea leaves for oolong tea (tea leaves for oolong tea 2) are used, almost the same results as the tea leaves for oolong tea 1 are obtained.

Example 4
The result using tea leaves for black tea is shown below. The same analysis method as in Example 1 was used except that the types of tea leaves were different.

Even when tea leaves 1 for tea are used, the tea temperature (**) suitable for the selective increase of isovitexin and PreChaA is different from the tea temperature (*) suitable for promoting the conversion from PreChaA to ChaA, the latter being the same Higher temperature.
In Example 4, a selective increase in isovitexin and PreChaA was remarkably observed in tea leaves (**) having a tea temperature of 135.5 to 165.6 ° C. 5 minutes and 12 seconds after charging the heating container. In tea leaves having a temperature of 173.4 ° C. or higher, no selective increase in isovitexin and PreChaA was observed. Since the tea temperature after 2 minutes of the tea leaves after 5 minutes and 12 seconds is 135.5 ° C. can be estimated to be about 125.7-126.7 ° C. (Table 1), the tea temperature after 2 minutes is about It is believed that a selective increase in isovitexin and / or PreChaA occurs at 125.7 ° C and above, perhaps at lower tea temperatures (about 115-120 ° C). The tea temperatures at the end of the tea leaf heating time after 16 minutes at 5 minutes and 12 seconds at 166.6 ° C. and 173.4 ° C. were about 168.9 to 169.3 ° C. and about 175.8 ° C., respectively. It can be presumed that the temperature was lower than 176.2 ° C. (= the tea temperature assuming that it was heated up to 6 minutes 48 seconds). Therefore, it can be seen that the tea temperature at the end of the heating step needs to be lower than about 175.8 ° C., that is, 170 ° C. or lower in order to cause a selective increase in isovitexin and / or PreChaA.
From the above, in order to cause a selective increase in isovitexin and / or PreChaA with respect to the dried tea leaves of black tea leaves, the tea temperature is about 115 to 170 ° C, more preferably about 115 minutes to 160 ° C, and about 4 minutes and 30 seconds. This heat treatment is considered effective.

  From the results of Examples 1 to 4, in order to selectively increase the content of isovitexin and / or PreChaA, the effective heating conditions for green tea, oolong tea, and tea leaves are as follows: It can be said that heating is performed within a range of 115 to 170 ° C, more preferably 115 to 165 ° C, and most preferably 120 to 160 ° C for about 4 minutes and 30 seconds.

Example 5
The heating time and the increase rate of isovitexin and / or PreChaA were examined. The set temperature of the heating vessel was the same as that of one of the examples (**) in which the selective increase in PreChaA was noticeable in Example 3, and analysis conditions other than the setting of the heating time were in accordance with Example 3.

  From Table 7, it can be seen that the selective increase of isovitexin and PreChaA is also observed in the heat treatment for 3 minutes and 40 seconds, but the tea leaves heated for 6 minutes and 30 seconds are more markedly increased. And in the example heated for 8 minutes and 30 seconds or more, since the increase in ChaA becomes remarkable, it can be seen that the heating time causing the selective increase in isovitexin and / or PreChaA is too long. Since it is considered that the tea temperature becomes 120 ° C. or more in less than 2 minutes after charging the tea leaves into the heating container (FIG. 2B), the heating time at the heating temperature suitable for selective increase of isovitexin and / or PreChaA is as follows: 1 minute 30 seconds to 4 minutes 30 seconds is considered appropriate.

Examples 6 and 7
Next, the heating conditions for promoting the conversion from PreChaA to ChaA were examined. The setting temperature of the first two sections of the heating container used in the present invention is set to 190 ° C., that is, the same setting temperature as that of the embodiment (**) in which PreChaA is selectively increased in Examples 1 and 2, and the third section is set to 190. The temperature was set higher than ° C. The analysis conditions other than the set temperature of the third section and the heating time are the same as those of the example performed at 190 ° C. in Example 1.

  Compared to Example 1, which was heated all the time at a temperature suitable for selective increase of isovitexin and PreChaA (here, Comparative Example), in Examples 7 and 8, which were treated at a higher temperature in the third compartment, the content of ChaA was higher. It increased remarkably 2.1 to 2.8 times. Moreover, even if it compares with the Example (*) in which the remarkable increase in ChaA was recognized in Examples 1 and 2, the content of ChaA is significantly higher. From these results, it was shown that the multi-stage heat treatment is superior to the constant temperature heating as the heat treatment for increasing the content of ChaA. In addition, compared with non-heated Comparative Example 1 (ChaA content is less than 0.1 μg / g tea leaves), in Examples 6 and 7, the ChaA content was increased about 448 to 593 times, that is, about 450 to 600 times. It will be.

  In Example 1, where the tea temperature at 15 minutes after 5 minutes and 12 seconds from the heating container was 155.5 ° C., almost no conversion from PreChaA to ChaA was observed, whereas the tea temperature was 184.9 to 197.9. In Example 6, which was at 0 ° C., PreChaA turned to decrease and was converted to ChaA. Therefore, if the tea temperature for 1 minute 18 seconds from the tea temperature measurement (5 minutes 12 seconds later) to the end of the heating process (6 minutes 30 seconds later) is higher than about 184.9 ° C, conversion from PreChaA to ChaA Was sufficiently promoted, and it was found that a tea leaf having an increased ChaA content was obtained.

Example 8-13
Therefore, the conditions for converting PreChaA to ChaA were examined in more detail using the methods of Examples 6 and 7.

In Examples 8 to 11 and 13, a significant increase in ChaA was observed in any tea leaves. Among these, the heating time was the shortest in Example 8, the longest was in Example 10, and the time from the tea temperature measurement to the end of the heating process was 1 minute 3 seconds and 1 minute 42 seconds, respectively ( Table 1). The tea temperature at the time of measurement was the lowest at 171.4 ° C. (Example 8), and the highest was 198.1 ° C. (Example 10). Therefore, from the above example, when the heat treatment is performed for 1 minute 3 seconds to 1 minute 42 seconds after the tea temperature reaches 171.4 to 198.1 ° C., the conversion from PreChaA to ChaA occurs significantly. Indicated.
In Example 12, almost no increase in the ChaA content was observed in tea leaves having a tea temperature of 163.7 ° C. or lower or 207.2 ° C. or higher after 5 minutes and 12 seconds. However, in the tea leaves in which the tea temperature is in the range of 179.7 to 203.8 ° C., the ChaA content is greatly increased by continuing to heat for 1 minute 18 seconds thereafter (*). The tea temperatures at the end of the tea leaf heating process after 5 minutes and 12 seconds were 203.8 ° C. and 207.2 ° C. were about 206.7-207.1 ° C. and about 210.1-210. It is considered that the temperature is lower than 5 ° C. (= the tea temperature assuming that it is heated up to 6 minutes 48 seconds) (Table 1). Therefore, from Example 12, it is shown that the conversion from PreChaA to ChaA is remarkably promoted by heating for about 1 minute 18 seconds in the range where the tea temperature is higher than 163.7 ° C and lower than 206.7 ° C. It was done.

  From the results of Examples 8 to 13, the dry tea leaves for green tea were heat treated for 1 to 3 minutes in the range of 171 to 205 ° C., thereby promoting the conversion from PreChaA to ChaA to ChaA. It is thought that the content can be greatly increased.

Examples 14 and 15
Table 10 shows the results of studies on tea leaves 1 and 2 for oolong tea according to the methods of Examples 8 to 13.

  From Example 14, although the tea temperature of 177.8-203.2 ° C. after 5 minutes and 12 seconds was further heat-treated for 1 minute and 18 seconds, the ChaA content was significantly increased (with non-heated Comparative Example 3 and Compared with an increase of about 7.3 to 9.3 times, ChaA is significantly reduced by thermal decomposition in tea leaves having a tea temperature of 208.3 ° C. The tea temperature at the end of the tea leaf heating process after 20 minutes and 20 seconds at 20 minutes and 208.3 ° C. was about 206.0 to 206.5 ° C. and about 211.2 to 20 ° C., respectively. It is considered that the temperature was lower than 211.6 ° C. (= tea temperature assuming that it was heated up to 6 minutes 48 seconds) (Table 1). Therefore, it is considered that the ChaA content is sufficiently increased if the tea leaf 1 for oolong tea is subjected to a heat treatment for about 1 to 3 minutes in the range of 171 to 205 ° C. Heat treatment in this range is also effective for other types of tea leaves for oolong tea, and about 5.9 to 6.0 times as much increase in ChaA content was observed in tea leaves 2 for oolong tea (Example 15). . Furthermore, although omitted in the present application, it was confirmed that the ChaA content significantly increased when the tea temperature for tea 1 was subjected to heat treatment for about 1 to 3 minutes in the range of 171 to 205 ° C. ing.

  Therefore, in any dry tea leaves for green tea, oolong tea, and black tea, to promote the conversion from PreChaA to ChaA and increase the ChaA content by heat treatment for 1 to 3 minutes, the tea temperature is increased to 171 to 205 ° C. It has become clear that it should be maintained within the range.

  As a general theory of chemical reaction, the reaction time can be shortened by raising the reaction temperature. Then, about the said heating process for accelerating | stimulating the conversion from PreChaA to ChaA and increasing ChaA content, it was examined whether heating time could be shortened by raising heating temperature.

Example 16
After heat treatment for selectively increasing isovitexin and PreChaA (= heating step 1) on tea leaf 1 for oolong tea, and then heat treatment (= heating step 2) under the heating conditions shown in Table 11, tea leaves The contents of PreChaA and ChaA contained in were analyzed. In the heating step 1, the condition (*) in which the measured tea temperature was 133.1 ° C. in Example 5 was used. The results are shown in Table 11.

In the example where the total heating time was 1 minute, the tea temperature was measured 48 seconds after the heating container was charged, and then the heating was continued for 12 seconds. Similarly, the tea temperature is measured after a total heating time of 1 minute 30 seconds, in a 2 minute embodiment, 1 minute 12 seconds, or 1 minute 36 seconds, and then heating continues for 18 seconds or 24 seconds. . Since the tea temperature within 2 minutes after the heating container changes rapidly (Fig. 2A, Fig. 2B), it is difficult to predict the tea temperature during this period, but the tea temperature from the time of measurement to the end of heating is higher than the measured tea temperature. It can be said that it was.
Considering the results in Table 11 in view of this, the heat treatment for only 12 seconds after the tea temperature reached 186.3 to 189.3 ° C. is approximately insufficient for promoting the conversion from PreChaA to ChaA. (Example 16). Similarly, even if heating was continued for 18 seconds after the tea temperature reached 193.8 to 196.3 ° C., the increase in ChaA was insufficient (Example 17). However, in the tea leaves in which the tea temperature reached 200.8 ° C. (Example 17), a significant increase in ChaA content was observed by continuing to heat for 18 seconds thereafter (about 5% compared to Comparative Example 7). .8 to 7.5 times). Furthermore, in Example 18 in which heating was continued for 24 seconds, it was shown that the ChaA content significantly increased when the tea temperature reached 201.8 to 227.8 ° C. (compared with Comparative Example 7). (5.9 to 8.6 times).
That is, it was revealed that the conversion from PreChaA to ChaA is significantly promoted by heating for 18 seconds at a tea temperature higher than 196.3 ° C. or 24 seconds at 201.8 ° C. or higher. From this, if the tea temperature reaches higher than 205 ° C., it is considered that the ChaA content is sufficiently increased by the heat treatment for about 15 seconds. And even if it heated for 24 seconds after reaching 227.8 degreeC, the ChaA high content tea leaf was obtained (Example 18), and it is estimated that the upper limit of the said tea temperature is around 240 degreeC.

  From the above results, if the tea temperature is higher than 205 ° C. and within the range of 240 ° C. or less, the heat treatment for 15 seconds to 30 seconds sufficiently promotes the conversion from PreChaA to ChaA and the chafloside A content is increased. A significant increase is expected.

  From the results so far (Examples 1 to 18), the tea temperature is 115 to 170 ° C., preferably 115 to 165 ° C., more preferably 120 for any dry tea leaves for green tea, oolong tea, and black tea. After the heat treatment for maintaining in the range of ~ 160 ° C for 1 minute 30 seconds to 4 minutes 30 seconds, more preferably 2 to 4 minutes, the tea temperature is 171 to 205 ° C, more preferably 175 to 200 ° C, Most preferably, the heat treatment is maintained in the range of 180 to 200 ° C. for 1 to 3 minutes, more preferably 1 minute 30 seconds to 2 minutes 30 seconds, most preferably 1 minute 30 seconds to 2 minutes, or the tea temperature is By performing a heat treatment at a temperature higher than 210 ° C. to 240 ° C., more preferably 215 to 235 ° C., most preferably 215 to 230 ° C. for 15 to 30 seconds, more preferably 20 to 30 seconds, It has been found that is increased contents of Furosaido A several times to several hundred times.

Examples 19 and 20
Next, the quality of tea leaves with increased chafloside A content obtained by the production method of the present invention as tea leaves for beverages was examined. According to Example 3, the tea leaves were extracted from the tea leaves that had undergone the heating step, and the sensory evaluation of the tea drinks was performed (Evaluation 1). In the comparative example, tea leaves having a higher ChaA content than the tea leaves used in the examples by constant temperature heat treatment at high temperature were used.

The tea beverage extracted from the tea leaves (Examples 19 and 20) subjected to the multistage heat treatment of the present invention is superior in sensory evaluation than the tea beverage extracted from the tea leaves (Comparative Examples 8 and 9) subjected to the constant temperature heat treatment. It was shown that. When asked the panelists about their impressions, the evaluation was “There is a refreshing feeling and the aftertaste is clean”.
Therefore, unlike the conventional constant temperature heat treatment method, it became clear that the use of the multi-stage heat treatment method according to the present invention not only increases the ChaA content but also improves the quality as a tea leaf for beverages. .

  Furthermore, sensory evaluation was also performed on the tea beverages extracted from the ChaA-rich tea leaves obtained in Examples 17 and 18 (Evaluation 2). From Table 13 below, it can be seen that the tea leaves subjected to the multi-stage heat treatment of the present invention are excellent not only in the ChaA content but also in all evaluation items.

Example 21
In the process of burning tea leaves, attempts have been made to improve the quality of tea beverages by adding heated steam-containing gas and far infrared rays. Therefore, the effects of heating steam and far infrared rays in the heating process according to the present invention were examined.
As the heating steam, a steam-containing gas heated to 200 ° C. or 260 ° C. was used. For far-infrared rays, a far-infrared ray generator was inserted from the tea leaf inlet of the heating container. It has been confirmed that far-infrared rays generated from the far-infrared ray generator reach about half of the heating container. Moreover, the method of (Evaluation 1) was used for sensory evaluation.

  The tea leaves to which far infrared rays were added had a burnt odor, and the sensory evaluation of the tea beverage extracted from the tea leaves was also very low. On the other hand, it became clear that addition of water vapor-containing gas improves the sensory evaluation of tea beverages. The improvement effect is greater for the steam-containing gas heated to 260 ° C. than 200 ° C. Further, although omitted in the present application, similar results were obtained for tea leaves other than green tea leaves 1. Therefore, the steam-containing gas heated to 260 ° C. was used for the subsequent analysis.

Examples 22-25
About tea leaves 1 and 2 for oolong tea, heat treatment of tea leaves was performed while blowing steam-containing gas heated to 260 ° C., and sensory evaluation of tea drinks extracted from the tea leaves was performed (Evaluation 2).

When Examples 21 and 22 and Examples 23 and 24 having the same setting temperature of the heating container are compared with each other, the tea temperature is reduced to 0. 0 by performing the heat treatment while blowing the steam-containing gas heated to 260 ° C. The temperature increased by 5 to 1.5 ° C, and the chafloside A content tended to increase slightly. And in sensory evaluation, the tea leaves to which the water vapor-containing gas is added always have a higher overall evaluation (an increase of 1.78 to 4.0 points). Therefore, the addition of the steam-containing gas heated to 260 ° C. in the tea leaf heating step according to the present invention further improves the quality of the tea beverage extracted from the tea leaf without impairing the increase in the chafuroside A content. It was shown that
Although omitted in the present application, the same quality improvement effect of the tea beverage as in the case of using the steam-containing gas heated to 260 ° C. is recognized even when the steam-containing gas heated to 240 to 280 ° C. is used. ing.

  From the above results, in the heating step for increasing the chafuroside A content of the tea leaves according to the present invention, the steam-containing gas heated to 240 to 280 ° C., preferably 250 to 270 ° C., most preferably 260 ° C. is blown. It has been clarified that the quality of the tea beverage extracted from the tea leaves after the heating process is further improved by performing the heating process.

Claims (6)

A method for producing a tea leaf for beverage by putting dry tea leaf having a water content in a range of 1 to 10% by mass into a heated heating container and heating the tea leaf while stirring, the heating step The temperature of the tea leaves in
After being maintained in the range of 115 ° C. to 170 ° C. for 1 minute 30 seconds to 4 minutes 30 seconds ,
171 ° C. or higher 205 ° C. or less of the range of 1 to 3 minutes, or 205 ° C. than kept 15-30 seconds at a high temperature and a range of 240 ° C. or less Rukoto,
A method for producing tea leaves for beverages having an increased content of chafuroside A. The method according to claim 1, wherein the heating container is a heating container divided into two or more sections,
The compartments are maintained at the same or different temperatures for each compartment, and
The tea leaves become the same or higher temperature as they move between the compartments;
A method for producing tea leaves for beverages. The method according to claim 1 or 2, further beverage tea leaves and performing said heating step while blowing steam-containing gas which has been heated to a temperature in the range of 240 ° C. or higher 280 ° C. or less in the heating vessel Manufacturing method. The method according to any one of claims 1 to 3 , wherein the dried tea leaves are dried tea leaves of non-fermented tea leaves. The method according to any one of claims 1 to 3 , wherein the dried tea leaves are dried tea leaves of semi-fermented tea leaves. The method according to any one of claims 1 to 3 , wherein the dried tea leaves are dried tea leaves of fermented tea leaves.

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