JP4583417B2 - Method for producing fermented tea - Google Patents

Description

  The present invention relates to a method for producing fermented tea, characterized in that tea leaves or a mixture of tea leaves and tea stems are subjected to two-stage fermentation. Hereinafter, unless otherwise specified, tea leaves and a mixture of tea leaves and tea stems are collectively referred to as tea leaves and the like.

  As the dietary habits of Japan become richer, the number of adults with symptoms of hyperlipidemia has increased, and as a result, it has become a problem inducing diseases such as obesity, arteriosclerosis, and thrombosis. As a prophylactic / therapeutic agent for hyperlipidemia, cholesterol lowering action contained in various foods has been attracting attention, and the functionality of teas, one of which has attracted attention.

  For example, fermented tea, which is a lipid metabolism improving action of puer tea, which is a kind of black tea of Chinese tea (see, for example, Non-Patent Document 1), and cholesterol temporarily reducing action of various black teas (see, for example, Non-Patent Document 2). ) Has been reported, and a blood glucose level increase-inhibiting substance composed of an extract of black tea having such an action is known (for example, see Patent Document 1).

  Extracts such as tea leaves contain catechins and theanine as functional substances. Theaflavins are catechins and oxidative derivatives of chlorogenic acid, and are produced in the fermentation process of tea leaves and the like. For this reason, green tea extracts that have not undergone an enzymatic oxidation process contain almost no theaflavins, but they are enzymatically oxidized and are commonly referred to as semi-fermented teas such as oolong tea and black tea, and mold and yeast. The extract of black tea, generally called post-fermented tea, fermented with various fungi, contains a high concentration.

  Moreover, the extract of fermented tea, such as tea leaves, contains tannin more than green tea. Examples of tannins in tea leaves include gallate derivatives of catechins, and actions such as antioxidant activity are recognized.

  The production of black tea, which is classified as post-fermented tea among fermented teas, generally requires a long-term fermentation with fungi, and has a unique flavor after a long-term aging process over several years. Become. Based on the inventor's knowledge, black tea having physiological activities such as cholesterol-lowering action and diabetes-improving action that are not found in oolong tea and black tea of green tea and oxidative fermented tea, but are found in black tea that is post-fermented tea It has been found that a fermentation period of about 40 days or more is usually required to produce.

  On the other hand, when producing fermented tea, the inventors produce black tea in a short period of time while maintaining physiological activities such as cholesterol lowering activity by fermenting tea leaves in the presence of tea stems. A method has been proposed (see Patent Document 2).

  Even in such a situation, from an industrial viewpoint, it is desired to improve the method for producing black tea in a short time while maintaining the characteristics of fermented tea.

Sano et al., 1986 Chem. Pharm. Bull (Tokyo) 34, 1, p221-228 Yang et al., Pharmaceutical Research, Vol. 35, no. 6, 1997: 505-512 JP 2002-370994 A JP 2005-333929 A

  In view of the above circumstances, the present invention is a method for producing black tea in a shorter period of time, and contains theaflavins and tannin, which are the characteristics of fermented tea, in a high concentration, and has the effect of improving diabetes. An object is to provide a manufacturing method.

  The first invention is a method for producing fermented tea in which tea leaves or a mixture of tea leaves and tea stems is fermented to achieve the above object, and (Step A) pretreatment at 30 to 40 ° C. for 2 to 48 hours Provided is a method for producing fermented tea, characterized by being subjected to a step of performing fermentation, and then (step B) a step of performing fermentation at 45 to 55 ° C. for 7 to 40 days.

  2nd invention is related with the manufacturing method of fermented tea of Claim 1 in which the mixture of a tea leaf and a tea stem contains 20-60 weight part of tea stems with respect to 100 weight part of tea leaves.

  3rd invention is related with the manufacturing method of fermented tea of Claim 1 or 2 which uses Aspergillus niger, Aspergillus oryzae, or Rhizopus delimer for the said fermentation.

  According to the method for producing fermented tea of the present invention, it is possible to produce black tea having a diabetes-improving action in a short period of time by containing theaflavin and tannin at high concentrations in the fermented tea and the extract of the fermented tea. Become.

  As tea leaves and tea stems used in the present invention, tea leaves and tea stems obtained from tea trees such as Chinese large leaf species, Chinese middle leaf species, Chinese small leaf species, Shan species, Assam species and the like can be used.

  The tea leaves used in the present invention may be heat-treated immediately after picking the tea leaves etc. for the purpose of preventing the oxidation reaction by enzymes contained in the tea leaves etc. before performing the fermentation treatment. Processed tea leaves such as oolong tea that has been self-digested with the included enzyme and semi-fermented once or fully fermented black tea may be used.

  The method of the present invention is characterized by fermenting a mixture of tea leaves and tea stems. The size of tea leaves and tea stems used for fermentation is not particularly limited. You may use as it is, and you may use what was cut with the crusher, the grinder, the mill, the ball mill, etc.

  The tea leaves and the like to be subjected to fermentation are humidified by spraying before fermentation, and the water content is preferably 30 to 60% by weight, more preferably 30 to 50% by weight (total amount 100% by weight). If the water content before fermentation is less than 30% by weight, fermentation tends to not proceed sufficiently, and if it exceeds 60% by weight, it will be spoiled by various bacteria, which is not preferable.

  The water content at the end of the fermentation is preferably 15 to 30% by weight, more preferably 16 to 20% by weight (total amount 100% by weight). When the amount of water at the end of fermentation exceeds 30% by weight, there is a tendency to cause spoilage, and when it is less than 15% by weight, there is a tendency that fermentation does not proceed sufficiently.

  The method of the present invention comprises a two-stage fermentation of step A and then step B performed. The pretreatment fermentation temperature in Step A is 30 to 40 ° C, preferably 32 to 39 ° C, and particularly preferably 35 to 38 ° C. If the fermentation temperature in step A is less than 30 ° C., the fermentation cannot be started quickly and a long fermentation period is required, so that the fermentation cannot be completed within 40 days in step B. If the fermentation temperature in step A exceeds 40 ° C., the fermentation proceeds locally excessively, so that the growth of mycelia concentrates in a very small part. As a result, the air permeability becomes worse due to adhesion of the tea leaves and the like, and conversely, spores cannot be formed and the hyphae cannot be extended throughout the tea leaves.

  The pretreatment fermentation time in Step A is 2 to 48 hours, preferably 2 to 36 hours. If the fermentation time of step A is less than 2 hours, the fermentation cannot be started quickly and a long fermentation period is required, so that the fermentation cannot be completed within 40 days in step B. If the fermentation time of the process A exceeds 48 hours, it is difficult to control the fermentation of the process B, which causes an interruption of the fermentation or rot, which is not preferable.

  After the process A, the fermentation temperature in the process B is reached by natural temperature increase or heat temperature increase by fermentation heat. The fermentation temperature in process B is 45-55 degreeC, Preferably it is 46-52 degreeC. If the fermentation temperature in step B is less than 45 ° C., the fermentation does not proceed sufficiently and the intended black tea cannot be obtained in a short period of time. If the fermentation temperature in step B exceeds 55 ° C., the fungus is killed and fermentation is not preferred.

  The fermentation period in Step B is 7 to 40 days, preferably 10 to 38 days. If the fermentation period in step B is less than 7 days, fermentation is not sufficient and the intended black tea cannot be obtained. If the fermentation period in Step B exceeds 40 days, it is not preferable because decay tends to proceed.

  The mixture of tea leaves and tea stems used in the present invention preferably contains 20 to 60 parts by weight, more preferably 30 to 40 parts by weight of tea stems per 100 parts by weight of tea leaves. If the stem of tea is less than 20 parts by weight with respect to 100 parts by weight of tea leaves, the air permeability during fermentation tends to decrease. When the amount of tea stem exceeds 60 parts by weight with respect to 100 parts by weight of tea leaves, the abundance of tea leaves decreases, and the amount of active ingredients (theaflavins and tannins) produced from tea leaves tends to decrease.

  When fermenting tea leaves or the like by the action of microorganisms by the method of the present invention, it is preferable to ferment by the action of fungi in order to sufficiently obtain the flavor and ingredients peculiar to fermented tea. Examples of the fungus that can be used in the present invention include fungi belonging to the genus Aspergillus or Rhizopus. Of these, Aspergillus niger, Aspergillus oryzae, and Rhizopus delemar are preferred for sufficiently producing theaflavins and tannins by fermentation. The fungi used for fermentation can be used alone or in combination of two or more.

  These strains can be obtained from the Independent Administrative Institution Product Evaluation Technology Foundation, ATCC and other strain distribution agencies and seed strain sales companies, for example, Akita Imano Corporation.

  In the present invention, to inoculate fungi into tea leaves, etc., a method of powder mixing tea leaves and fungi spores as they are, the fungal spores are premixed with a food excipient such as wheat flour, rice flour, barley flour, Examples include a method of diluting a fungal spore and then mixing it with tea leaves or the like, a method of suspending a fungal spore in physiological saline or the like and spraying it on a tea leaf or the like.

  In this invention, it is preferable to start fermentation by inoculating 0.001-1 weight part of fungi with respect to 100 weight parts of tea leaves etc., and 0.01-0.5 weight part is more preferable. If the amount of inoculated fungi is less than 0.001 part by weight, the fermentation may not proceed sufficiently, and if it exceeds 1 part by weight, it is not preferable from the economical viewpoint that the production cost is excessive.

  Tea leaves inoculated with fungi can be fermented on a bed in the fermentation chamber. The components of the obtained fermented tea can be extracted by, for example, putting fermented tea leaves or the like in an extraction tank and adding water or hot water. The obtained extract is subjected to solid-liquid separation by centrifugation, and then foreign matters and the like are removed by a filter press to obtain an extract. Such extracts can be concentrated or further dried. Examples of such a concentration method include, but are not limited to, vacuum concentration, membrane concentration, freeze concentration, and the like. Drying can be performed by using a device such as spray drying, freeze drying, kneader, or Nauta mixer. . The obtained concentrated liquid or powder can be used as a functional food as it is or as a powder extract as it is or added to other foods.

  The extract of tea leaves and the like thus obtained exhibits α-glucosidase inhibitory activity. Living organisms cannot absorb ingested starch and saccharides as they are, and cannot absorb them unless they are broken down into monosaccharides. α-Glucosidase is an important enzyme involved in this degradation and is the only enzyme that is present on the mucous membrane of the small intestine and breaks down maltose and sucrose produced from ingested starch into monosaccharides, thus inhibiting this enzyme. The substance inhibits the absorption of sugar, thereby suppressing an increase in blood glucose level, and further exhibits an action for improving diabetes. Actually, inhibitors having an α-glucosidase action are used as pharmaceuticals (such as acarbose and voglibose).

Although the foodstuff which can add the said extract is not specifically limited, The following can be illustrated.
(1) Agricultural and fishery products Harusame, Koshian, Konnyaku, Bread, Noodles (immediate noodles, pasta, raw noodles, dried noodles), rice cakes, cereal foods, processed soybean products (tofu, soymilk, natto, frozen tofu), processed fishery products (paste products) , Salmon, crab-flavored crab, fish ham, fish sausage, fish wiener, sprinkles, green tea paste, egg-containing food (soup, salmon, etc.), canned food (oil sardine, yakitori), retort food (curry, stew, spaghetti) etc).
(2) Dairy products Milk, processed milk, lactic acid bacteria beverages, butter, cheese, condensed milk, powdered milk.
(3) Confectionery Cake, mousse, dessert, ice cream, candy, chocolate, gummy, candy, cookie, wafer, jelly.
(4) Seasoning Miso, soy sauce, umami flavor seasoning, powdered natural seasoning, sauce, dressing, grilled meat sauce, mirin, curry, stew, spice, spice, yogurt.
(5) Beverages Soft drinks (carbonated drinks, fruit drinks, sports drinks, nutritional drinks), beverages (coffee, cocoa, wort).
(6) Health food (dietary supplement)
Saponin-containing foods (Ginseng root-containing foods, Ezokogi-containing foods), sugar-containing foods (fructooligosaccharide-containing foods, isomaltoligosaccharide-containing foods, galactooligosaccharide-containing foods), polysaccharides (shiitake-containing foods, mucopolysaccharide / protein-containing foods, chondroitin Sulfuric acid-containing foods, garlic mushrooms (reishi) -containing foods), chitin / chitosan-containing foods), mineral-containing foods (calcium-containing foods, alfalfa-containing foods, prunes extract foods, beta-carotene-containing foods), fats and oils-containing foods, vitamin E-containing fats and oils , Wheat (wheat, pigeon) germ oil, soybean germ oil, rice germ oil, food containing eicosapentanoic acid, food containing soybean lecithin, food containing gamma linolenic acid (primrose oil, borage oil), food containing docosahexaenoic acid, protein Food (food containing soybean protein, casein, whey White, carp processed foods), taurine-containing foods (oysters processed foods, freshwater clam processed foods).
(7) Other processed foods, processed foods for abnormal amino acid metabolism, liquid food (disease food).

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

Example 1
Chinese large leaf tea leaves were harvested, and the tea leaves were placed in a direct-fired kettle and roasted at 90 ° C. for 25 minutes. After standing to cool, spray with warm water using a spray bottle to bring the water content to 32% by weight (100% by weight in total) and the temperature of the tea leaves to 37 ° C., and then put it into the fermentation room. Aspergillus niger , Manufactured by Akita Imano Co., Ltd.) was added and mixed well with 100 parts by weight of tea leaves. The temperature in the fermentation chamber was set to 35 ° C., and pretreatment fermentation was performed at the same temperature for 24 hours (Step A). Next, after the temperature in the fermentation chamber naturally increased to 50 ° C., fermentation was performed at the same temperature of 50 ° C. for 24 days (step B).

  198 g of the obtained fermented tea was put into an extraction tank, 1000 mL of water was added, and the mixture was heated at 120 ° C. for 1 hour to obtain 1150 mL of a crude extract. The crude extract was centrifuged and then subjected to filter press to remove foreign matters and obtain an extract. The extract was concentrated and freeze-dried to obtain 41 g of extract. The amount of extract per 100 g of the obtained fermented tea was 20.7 g (see Table 1).

Measurement of the amount of theaflavins The above extract was dissolved again in water, and the amount of theaflavins was measured by HPLC analysis using a reverse phase column. The results are shown in Table 2 as the amount of theaflavin (mg) contained in 1 g of the extract and the amount of theaflavin (mg) per 100 g of tea leaves as the raw material.

Measurement of tannin amount The above extract was dissolved again in water, and the total tannin amount was measured by a colorimetric method based on the iron tartrate method. The results are shown in Table 2 as the amount of tannin (g) contained in 100 g of the extract and the amount of tannin (g) per 100 g of tea leaves as a raw material.

Measurement of enzyme (α-glucosidase) activity The composition of the reaction solution was 0.7 mL of a 60 mM substrate solution (dissolved in sucrose in 0.1 M potassium phosphate buffer (pH 6.3)), test substance solution (extract above) 0.2 mL of a 50% by weight dimethyl sulfoxide aqueous solution) and enzyme solution (rat small intestine acetone powder (manufactured by Sigma) dissolved in 0.1 M potassium phosphate buffer (pH 6.3) at 100 mg / mL) ) 0.1 mL (1.0 mL in total). The extract concentration in the reaction solution was 10 mg / mL. This reaction solution was reacted at 37 ° C. for 15 minutes, and the reaction was stopped by adding 1.5 ml of 2M Tris-HCl buffer (pH 7.0) to prepare a test solution.

The amount of glucose produced by the enzyme reaction was measured with a commercially available kit (Glucose B Test Wako (manufactured by Wako Pure Chemical Industries, Ltd.)) 200 μL of the kit coloring reagent and 50 μL of the test solution per well were added to a 96-well microplate, After incubating at 37 ° C. for 30 minutes, absorbance at 490 nm was measured with a microplate reader (BIO RAD, MODEL 550) In the above reaction solution, 0.1 M potassium phosphate buffer (pH 6.3) was used instead of the substrate solution. ) _Was taken as the blank value, and the value obtained by subtracting the blank value from the absorbance value was _designated as A _490s, and the absorbance when the 50% by weight dimethyl sulfoxide aqueous solution was added instead of the test solution was taken as the control value (A _{490 c)} and then to determine the α- glucosidase inhibitory activity by the following equation. the measurement was conducted twice It was the measured value of the average value.
α-glucosidase inhibitory activity (%) = [(A _490c −A _490s ) / A _490c ] × 100
The results are shown in Table 2.

Examples 2-6
The tea leaves in Example 1 are 20 parts by weight (Example 2), 30 parts by weight (Example 3), 40 parts by weight (Example 4), 50 parts by weight (Examples) of tea stems with respect to 100 parts by weight of tea leaves. 5) or 60 parts by weight (Example 6) Except for changing to a mixture of tea leaves and tea stems, fermentation was performed in the same manner as in Example 1 to obtain an extract.

Comparative Example 1
The tea leaves in Example 1 were fermented in the same manner as in Example 1 except that they were changed to a mixture of tea leaves and tea stems containing 70 parts by weight of tea stems with respect to 100 parts by weight of tea leaves to obtain an extract. It was.

  For Examples 2 to 6 and Comparative Example 1, the amount of the extract obtained is shown in Table 1, the amount of theaflavins and tannin measured in the same manner as in Example 1, and the α-glucosidase inhibitory activity of the extract are shown in Table 2. .

  According to Table 1, even when the content of tea stem was increased to 60 parts by weight with respect to 100 parts by weight of tea leaves (Examples 1 to 6), no decrease in the amount of extract was observed. In Comparative Example 1 in which the content of the tea stem is 70 parts by weight with respect to 100 parts by weight of the tea leaves, it can be seen that the amount of the extract decreases.

  According to Table 2, even when the tea stem content was increased to 60 parts by weight with respect to 100 parts by weight of tea leaves (Examples 1 to 6), theaflavins content and tannin content and the extract's α-glucosidase inhibitory activity There was no decline. In Comparative Example 1 where the tea stem content is 70 parts by weight with respect to 100 parts by weight of tea leaves, it can be seen that the theaflavins content, the tannin content, and the α-glucosidase inhibitory activity of the extract tend to decrease. .

Examples 7-11
The tea leaves in Example 1 were changed to a mixture of tea leaves and tea stems containing 30 parts by weight of tea stems with respect to 100 parts by weight of tea leaves, and step A was performed at 32 ° C. for 2 hours (Example 7), 32 ° C. 36 hours (Example 8), 35 hours at 19 ° C. (Example 9), 38 ° C. for 5 hours (Example 10) and 38 ° C. for 48 hours (Example 11). An extract was obtained by fermentation in the same manner.

Comparative Examples 2 and 3
The tea leaves in Example 1 were changed to a mixture of tea leaves and tea stems containing 30 parts by weight of tea stems with respect to 100 parts by weight of tea leaves, and step A was performed at 25 ° C for 36 hours (Comparative Example 2) and 45 ° C. The sample was fermented in the same manner as in Example 1 except that the extraction was performed for 48 hours (Comparative Example 3).

  For Examples 7 to 11 and Comparative Examples 2 and 3, the amount of the extract obtained is shown in Table 3, the amount of theaflavins and tannin measured in the same manner as in Example 1, and the α-glucosidase inhibitory activity of the extract are shown in Table 4. Shown in

  According to Table 3, the fermentation temperature of the process A is in the range of 30 to 40 ° C., and in Examples 7 to 11 in which the fermentation time is in the range of 2 to 48 hours, the amount of extract obtained is large and the fermentation is sufficiently Shows progress. On the other hand, in Comparative Example 2 where the fermentation temperature in Step A is 25 ° C. and Comparative Example 3 where it is 45 ° C., it can be seen that the amount of extract obtained is reduced.

  According to Table 4, in Examples 7 to 11 where the fermentation temperature in Step A is in the range of 30 to 40 ° C. and the fermentation time is in the range of 2 to 48 hours, fermented tea having a high theaflavin content and tannin content is obtained. It turns out that it is obtained. Moreover, it is shown that the alpha-glucosidase inhibitory activity of the extract in Examples 7-11 is also high. On the other hand, in Comparative Example 2 in which the fermentation temperature in Step A is 25 ° C. and in Comparative Example 3 in which it is 45 ° C., the theaflavins content, tannin content and α-glucosidase inhibitory activity are all reduced. This is clearly shown in Comparative Example 3 where the fermentation temperature of A is high.

Examples 12-17
The tea leaves in Example 1 were changed to a mixture of tea leaves and tea stems containing 30 parts by weight of tea stems with respect to 100 parts by weight of tea leaves, and step B was carried out at 47 ° C for 8 days (Example 12) at 47 ° C. Example 1 with the exception of 38 days (Example 13), 32 days at 50 ° C. (Example 14), 20 hours at 52 ° C. (Example 15), 7 days at 54 ° C. and 38 days at 54 ° C. An extract was obtained by fermentation in the same manner.

Comparative Examples 4 and 5
The tea leaves in Example 1 were changed to a mixture of tea leaves and tea stems containing 30 parts by weight of tea stems with respect to 100 parts by weight of tea leaves, and step B was performed at 42 ° C. for 8 days (Comparative Example 4) and at 58 ° C. An extract was obtained by fermentation in the same manner as in Example 1 except that it was performed for 38 days (Comparative Example 5).

  For Examples 12 to 17 and Comparative Examples 4 and 5, the amount of the extract obtained is shown in Table 5, the amount of theaflavins and tannin measured in the same manner as in Example 1, and the α-glucosidase inhibitory activity of the extract are shown in Table 6. Shown in

  According to Table 5, in Examples 12 to 17 where the process B fermentation temperature is in the range of 45 to 55 ° C. and the fermentation period is in the range of 7 to 40 days, the amount of extract obtained is large and the fermentation proceeds sufficiently. Is shown. On the other hand, in Comparative Example 4 where the fermentation temperature in Step B is 42 ° C. and Comparative Example 5 where the fermentation temperature is 58 ° C., it can be seen that the amount of extract obtained is reduced.

  According to Table 6, in Examples 12 to 17 where the process B fermentation temperature is in the range of 45 to 55 ° C. and the fermentation period is in the range of 7 to 40 days, fermented tea having a high theaflavin content and tannin content is obtained. I understand that It is also shown that the extract has a high α-glucosidase inhibitory activity. On the other hand, Comparative Example 4 in which the fermentation temperature in Step B is 42 ° C. and Comparative Example 5 in which the fermentation temperature is 58 ° C. show that the theaflavins content, tannin content and α-glucosidase inhibitory activity all decrease. In Comparative Example 5 where the fermentation temperature of B is high, a decrease in the α-glucosidase inhibitory activity is markedly exhibited.

Examples 18-22
Aspergillus niger was added in an amount of 0.8 part by weight (Example 18), 0.2 part by weight (Example 19), 0.05 part by weight (Example 20), and 100 parts by weight of tea leaves. An extract was obtained by fermentation in the same manner as in Example 1 except that the content was 01 parts by weight (Example 21) or 0.001 parts by weight (Example 22).

Comparative Example 6
An extract was obtained by fermentation in the same manner as in Example 1 except that the amount of Aspergillus niger added was 0.0005 parts by weight with respect to 100 parts by weight of tea leaves.

  For Examples 18 to 22 and Comparative Example 6, the amount of the extract obtained is shown in Table 7, and the amount of theaflavins and tannin measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract are shown in Table 8. .

  According to Table 7, with respect to 100 parts by weight of tea leaves, when the amount of Aspergillus niger added is in the range of 0.001 to 0.8% by weight (Examples 18 to 22), there is no significant difference in the amount of extract obtained. However, it can be seen that when the amount of Aspergillus niger added is 0.0005 parts by weight (Comparative Example 6), the amount of the extract decreases.

  According to Table 8, when the amount of Aspergillus niger added is 0.001 to 0.8% by weight with respect to 100 parts by weight of tea leaves (Examples 18 to 22), theaflavins content and tannin content, and α of the extract -No decrease in glucosidase inhibitory activity was observed. It can be seen that Comparative Example 6 in which the amount of Aspergillus niger added is 0.0005 parts by weight tends to decrease both the theaflavins content, the tannin content, and the α-glucosidase inhibitory activity of the extract.

Comparative Examples 7-11
Chinese large leaf tea leaves were harvested, and the tea leaves were placed in a direct-fired kettle and roasted at 90 ° C. for 25 minutes. After standing to cool, spray with warm water using a spray bottle to set the moisture content to 32% by weight (100% by weight in total) and the temperature of the tea leaves to 37 ° C., and then put it into the fermentation room. Aspergillus niger 0.1 part by weight was added to 100 parts by weight of tea leaves and mixed well. This mixture was stirred at 35 ° C. for 24 hours (Comparative Example 7), 25 ° C. for 7 days (Comparative Example 8), 25 ° C. for 38 days (Comparative Example 9), 54 ° C. for 7 days (Comparative Example 10), and 54 ° C. And fermented for 38 days (Comparative Example 11).

  The obtained fermented tea obtained an extract by the same method as in Example 1. About Comparative Examples 7-11, the amount of obtained extracts is shown in Table 9, and the amounts of theaflavins and tannins measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extracts are shown in Table 10.

  Comparative Example 7 having a short fermentation time and Comparative Examples 8 and 9 having a low fermentation temperature had a small amount of extract according to Table 9, and according to Table 10, the amounts of theaflavins and tannins and α-glucosidase of the extract It can be seen that the inhibitory activity also shows a low value.

  Comparative Examples 10 and 11 correspond to those in which fermentation was performed without passing through the fermentation process according to Process A in Examples 16 and 17, respectively. According to Table 9, it was revealed that Comparative Examples 10 and 11 had a smaller extract amount than Examples 16 and 17, and fermentation did not proceed at an early stage without Step A. Further, according to Table 10, it can be seen that, without step A, the theaflavins content, tannin content, and α-glucosidase inhibitory activity all show low values.

Examples 23 to 28 and Comparative Example 12
Fermentation was carried out in the same manner as in Examples 1 to 6 and Comparative Example 1 except that the fungus used for fermentation was changed to Aspergillus oryzae (for separately selected miso, manufactured by Higuchi Matsunosuke Shoten) instead of Aspergillus niger. To obtain an extract. Table 11 shows the amount of the extract obtained, and Table 12 shows the amounts of theaflavins and tannins measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract.

  According to Table 11, even when the tea leaves are fermented using Aspergillus oryzae, the content of the tea stem is within the range of 60 parts by weight or less with respect to 100 parts by weight of the tea leaves (Examples 23 to 28). There was no decline. In Comparative Example 12 in which the content of the tea stem is 70 parts by weight with respect to 100 parts by weight of the tea leaves, it can be seen that the amount of the extract decreases.

  According to Table 12, even when the tea stem content was increased to 60 parts by weight with respect to 100 parts by weight of tea leaves (Examples 23 to 28), no decrease in tannin content was observed, and α-glucosidase inhibition of the extract was observed. The activity was also high. On the other hand, in Comparative Example 12, in which the content of tea stem is 70 parts by weight with respect to 100 parts by weight of tea leaves, the theaflavins content, tannin content, and α-glucosidase inhibitory activity of the extract tend to decrease. I understand.

Comparative Examples 13-17
The fungus used for fermentation was changed to Aspergillus oryzae (assorted miso, manufactured by Higuchi Matsunosuke Shoten) instead of Aspergillus niger, fermented in the same manner as in Comparative Examples 7 to 11, and extracted. Got. Table 13 shows the amount of the extract obtained, and Table 14 shows the amount of theaflavins and tannin measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract.

  Even when fermented with Aspergillus oryzae, Comparative Example 13 with a short fermentation time and Comparative Examples 14 and 15 with a low fermentation temperature had a small amount of extract, the amount of theaflavins and tannins, and α-glucosidase inhibition of the extract. It can be seen that the activity is also low (Tables 13 and 14). Furthermore, when fermented without going through the process A (Comparative Examples 16 and 17), it can be seen that the extract amount, the theaflavins content, the tannin content and the α-glucosidase inhibitory activity are all low (Tables 13 and 14). .

Examples 29 to 34 and Comparative Example 18
An extract was obtained by fermenting in the same manner as in Examples 1 to 6 and Comparative Example 1 except that the fungus used for fermentation was changed to Aspergillus niger and replaced with Rhizopus delimer (ATCC 34612). The obtained extract amount is shown in Table 15, and the theaflavins amount and tannin amount measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract are shown in Table 16.

  According to Table 15, when fermenting tea leaves and the like using Rhizopus delimer, the content of the tea stem is 60 parts by weight or less with respect to 100 parts by weight of tea leaves (Examples 29 to 34). There was no decline.

  According to Table 16, even when the tea stem content was increased to 60 parts by weight with respect to 100 parts by weight of tea leaves (Examples 29 to 34), no decrease in tannin content was observed, and the extract was inhibited by α-glucosidase. The activity was also high. On the other hand, in Comparative Example 18 in which the content of tea stem is 70 parts by weight with respect to 100 parts by weight of tea leaves, the theaflavins content, tannin content, and α-glucosidase inhibitory activity of the extract tend to decrease. I understand that.

Comparative Examples 19-23
A fungus used for fermentation was fermented in the same manner as in Comparative Examples 7 to 11 except that Aspergillus niger was replaced with Rhizopus derimer (ATCC 34612) to obtain an extract. The obtained extract amount is shown in Table 17, and the theaflavins amount and tannin amount measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract are shown in Table 18.

  Even when fermented with Rhizopus delimer, in Comparative Example 19 having a short fermentation time and Comparative Examples 20 and 21 having a low fermentation temperature, the amount of the extract was small, the amount of theaflavins and tannins, and the α-glucosidase inhibition of the extract. It can be seen that the activity is also low (Tables 17 and 18). Further, when fermented without going through step A (Comparative Examples 22 and 23), it can be seen that the extract amount, the theaflavins content, the tannin content and the α-glucosidase inhibitory activity are all low (Tables 17 and 18). .

Comparative Examples 24-29
The microorganism used for fermentation was fermented in the same manner as in Examples 1 to 6 and Comparative Example 1 except that Bacillus Natto (ATCC15245) was used instead of Aspergillus niger to obtain an extract. . The amount of the extract obtained is shown in Table 19, and the amount of theaflavins and tannin measured in the same manner as in Example 1 and the α-glucosidase inhibitory activity of the extract are shown in Table 20.

  When using Bacillus natto, fermentation of tea leaves or the like does not proceed, the amount of the extract is small, the amount of theaflavins and tannins, and the α-glucosidase inhibitory activity of the extract are also low (Tables 19 and 20).

Claims (3)

A method for producing fermented tea in which tea leaves or a mixture of tea leaves and tea stems is fermented, wherein (Step A) a step of pretreatment fermentation at 30 to 40 ° C. for 2 to 48 hours, and then (Step B) 45 to 55 A method for producing a fermented tea, characterized by being subjected to a step of performing fermentation at 7 ° C for 7 to 40 days. The method for producing fermented tea according to claim 1, wherein the mixture contains 20 to 60 parts by weight of tea stems with respect to 100 parts by weight of tea leaves. The method for producing fermented tea according to claim 1 or 2, wherein Aspergillus niger, Aspergillus oryzae or Rhizopus delimer is used for the fermentation.