Gardenia tea leaf extract and preparation method thereof

Abstract

The invention belongs to a preparation method of a plant extract, and particularly relates to a bright yellow-green to blue cape jasmine tea extract and a preparation method thereof. The preparation method of the gardenia tea leaf extract comprises the following steps: taking a mixture of gardenia fruits and tea leaves as a raw material, and performing enzymolysis to obtain the gardenia tea leaf extract which is bright green to blue. The method comprises the following steps: reacting amino acids contained in gardenia and tea leaves, amino acids and peptides generated after enzyme treatment by using tannase, protease and beta-glucosidase, and genipin generated after enzyme reaction of geniposide contained in the gardenia by using the enzymes to generate blue pigment; by adjusting the residual amount of the yellow pigment components gardenia yellow and crocein contained in the gardenia, blue and yellow are mixed to be green. The gardenia tea extract disclosed by the invention does not need pigment identification, is heat-resistant, is insensitive to pH value change, and presents bright green to blue.

Description

Technical Field

[0001] This invention pertains to methods for preparing plant extracts, particularly gardenia and tea extracts that exhibit a bright yellow-green to blue color, and their preparation method. Background Technology

[0002] Known blue colorants used in food and other applications include Food Blue No. 1 (disodium 2-(bis{4-[N-ethyl-N-(3-sulfonylphenylmethyl)amino]phenyl}methylonyl)benzenesulfonate), spirulina pigment, and gardenia blue pigment. Food Blue No. 1 and spirulina pigment are bright, low in red, high in yellow, and exhibit a vivid blue hue. However, because Food Blue No. 1 is a synthetic colorant, there is a trend of consumers avoiding its use as their awareness of food safety increases. Furthermore, while spirulina pigment is a natural pigment, it is prone to fading due to heat and is also expensive. Gardenia blue pigment, on the other hand, is not only a natural pigment but also heat-stable, overcoming the aforementioned drawbacks of Food Blue No. 1 and spirulina pigment, and is therefore widely used in the food industry.

[0003] Gardenia (scientific name: Gardenia jasminoides var. jasminoides Gardenia (Gardenia) is an evergreen broad-leaved shrub belonging to the Rubiaceae family and the Gardenia genus. Its flowers are fragrant and sweet, earning it the reputation as one of the "Three Great Fragrant Trees." Gardenia tea, jasmine tea, and osmanthus tea are considered among the most representative flower teas in China and are widely loved. In addition, gardenia fruit has the effects of maintaining and improving blood flow and liver health, as well as anti-inflammatory effects. It can be used as a raw material in traditional Chinese medicine and can also be brewed into tea. Furthermore, due to its yellow, blue, and red pigment components and its relative stability to changes in light, heat, and pH, it is widely used for food coloring. Gardenia yellow pigment is easily extracted with water, making it convenient for home use and also used for coloring ingredients such as chestnut cakes in festive dishes. Gardenia blue pigment requires the iridoid glycosides contained in the fruit to react with β-glucosidase to produce genipin, which then combines with protein hydrolysates such as HVP to develop color. Therefore, when using gardenia blue pigment, it should be labeled as "gardenia blue pigment," "gardenia colorant," or "coloring agent (gardenia)."

[0004] Green colorants used in foods include synthetic colorants food green No. 3 (fast green FCF) and food green No. 4 (green S), which are stable to light, heat, and pH changes, but are avoided in health-conscious products. Chlorophyll, spirulina pigment, gardenia green pigment, and the like are used as natural pigments. Chlorophyll is a natural pigment contained in most plants, and is highly safe and suitable for health-conscious people, but magnesium-bound chlorophyll is not resistant to light and heat, and is sensitive to pH changes, and easily fades and browns. Although there are also more stable zinc- or copper-bound chlorophyll preparations, their use in foods is limited. Spirulina pigment is characterized by bright and vivid green color, but, as described above, it is not resistant to heat, and thus can be used only in ice cream and jelly and the like. In addition, gardenia green pigment preparations mixed by blending gardenia blue pigment and safflower yellow pigment are excellent in heat resistance and pH stability, and are widely used as colorants in beverages and baked goods.

[0005] Patent Document 1 (Japanese Patent Publication No. 2022-86917) discloses that plant green pigment chlorophyll is stabilized by adding black ginger extract or citrus extract.

[0006] Patent Document 2 (Japanese Patent Publication No. 2020-137455) discloses a method for producing green juice in which green color is maintained for a long period by adding copper ions or calcium ions.

[0007] Patent Documents 3 and 4 (Japanese Patent No. 5184711, Japanese Patent No. 7503064) cite examples in which copper chlorophyll is used to stabilize green color and applied to green tea and edible oil. However, copper chlorophyll is a chemical synthetic additive, and has a food use standard, and must be labeled as "colorant (chlorophyll copper)" or the like.

[0008] Similarly, Patent Document 5 (Japanese Patent Publication No. 2005-333862) also discloses examples in which additives containing copper ions or zinc ions (inorganic salts, gluconate) are used in combination with chlorophyll-containing raw materials during food production to stabilize green color. However, these have a use standard, and must be labeled as additives.

[0009] Patent Document 6 (Japanese Patent Publication No. 2004-41237) also cites an example in which zinc-containing yeast is used in combination, and can be applied to some plastic bottle green tea beverages, but has a yeast-derived aroma, and the yeast can precipitate over time, which can reduce the value of the food. SUMMARY

[0010] The technical problem to be solved by the present application is to provide a preparation method for gardenia • tea leaf extract, which is a coloring plant extract that can be applied to foods.

[0011] To solve the above technical problems, the present application provides a preparation method of gardenia • tea extract: taking the mixture of gardenia fruits and tea leaves as raw material, after enzymolysis, the gardenia • tea extract (bright green to blue gardenia • tea extract) is obtained.

[0012] In the present application: the amino acids contained in gardenia and tea, the amino acids and peptides generated after enzymatic treatment of the amino acids using tannase, protease and β-glucosidase, and the genipin generated after enzymatic reaction of geniposide contained in gardenia using the above enzymes react to generate blue pigment; by adjusting the residual amount of yellow pigment components in gardenia (gardenia yellow and crocetin), the mixture of blue and yellow is green.

[0013] As an improvement of the preparation method of gardenia • tea extract of the present application, the following steps are included: 1) Mix gardenia fruits and tea leaves to obtain a mixed raw material, wherein the weight content of tea leaves in the mixed raw material is 5-95%; Add water to the mixed raw material at 90±10℃ and stir for 15±5 minutes; the weight ratio of the mixed raw material: water is 1:8-12; Note: By adjusting the mixing ratio of gardenia and tea, the color of gardenia • tea extract can be arbitrarily adjusted from yellow-green to blue; 2) Cool the product obtained in step 1) to the enzymolysis temperature, adjust the pH value to 4.5-7.2 (preferably 4.8-6.5, more preferably 6.0); add tannase and protease, and incubate at the enzymolysis temperature for 0.5-24 hours (preferably 1-16 hours, more preferably 3-5 hours) for the first enzyme reaction; the tannase: mixed raw material = 100-500 U / 100 g, and the protease: mixed raw material = 7000-9000 U / 100 g; Then, add β-glucosidase and incubate at the enzymolysis temperature for 0.5-15 hours (preferably 1-5 hours, more preferably 3-5 hours) for the second enzyme reaction; the β-glucosidase: mixed raw material = 800-2500 U / 100 g; The enzymolysis temperature is 30-60℃ (preferably 40-50℃); Note: The amino acids contained in gardenia and tea, the amino acids and peptides generated after enzymatic treatment of the amino acids using the above enzymes, and the genipin generated after enzymatic reaction of geniposide contained in gardenia using the above enzymes react to generate blue pigment; and by mixing the yellow pigment components (including crocetin and crocetin) contained in gardenia, the color of gardenia • tea extract can be arbitrarily adjusted from yellow-green to blue.

[0014] 3) Separate (solid-liquid separation) the product obtained in step 2); the liquid obtained by separation is the enzyme reaction liquid; The enzyme reaction solution is heated to deactivate the enzyme, and then cooled to ≤30℃, 10%~100% polyvinylpyrrolidone based on the weight of the gardenia fruit is added, slowly stirred at 30±5℃ for 15±5 minutes, and then filtered with filter paper. The obtained filtrate (clear liquid) is the gardenia • tea extract.

[0015] Description: The gardenia • tea extract is heated to sterilize (at 95℃ for 15 minutes) to deactivate the enzyme, and then aseptically filled as the product.

[0016] By controlling the amount of polyvinylpyrrolidone (PVPP) used, the remaining amount of yellow pigment components (including crocin, crocetin) contained in the gardenia is selectively adsorbed and removed, so as to adjust the color of the gardenia • tea extract to yellow-green to blue.

[0017] As a further improvement of the preparation method of the gardenia • tea extract of the present application, in step 2), 1M sodium bicarbonate is used to adjust the pH value.

[0018] As a further improvement of the preparation method of the gardenia • tea extract of the present application, the tea is non-fermented tea (non-fermented tea steamed, non-fermented tea pan-fried), semi-fermented tea, or fermented tea.

[0019] Especially preferred are non-fermented tea and semi-fermented tea with fresh and strong aroma.

[0020] The present application also simultaneously provides a food-grade pigment: mixing several kinds of gardenia • tea extract to adjust to the desired yellow-green to blue food-grade pigment.

[0021] Description: The food-grade pigment can be used to produce yellow-green to blue liquid food, semi-solid food, and solid food. The addition amount is generally 0.1~5.0%.

[0022] The gardenia • tea extract of the present application does not need pigment identification, and is heat-resistant, not sensitive to pH value changes, and presents bright green to blue.

[0023] The present application has been intensively studied with the development of plant extracts as the subject, and it has been found that: after mixing gardenia with tea and performing certain enzyme treatment, a gardenia • tea extract that is not easy to fade and brown over time, is safer, does not need to be labeled with a colorant, and presents green to blue can be produced, thereby completing the present application.

[0024] In the present application, in order to quantify the color of the extract of the present application, when the absorbance at λ605nm measured by a spectrophotometer is set as A, and the absorbance at 480nm is set as B, the value of A / B is in the range of 0.47 to 2.5.

[0025] In summary, the present application obtains a green and non-fading gardenia • tea extract by mixing gardenia and tea and subjecting them to enzymatic treatment. In addition, the obtained gardenia • tea extract can be used in food, beverage and powder compositions containing the extract.

[0026] The present application has the following technical advantages: The gardenia • tea extract obtained by the preparation method of the present application exhibits a bright green to blue color, and is stable to light, heat and pH changes. By adding the extract to food and the like, green and non-fading food and the like can be obtained.

[0027] The tea used in the present application is not particularly limited, and examples thereof include steamed non-fermented tea such as sencha, bancha, kabusecha, gyokuro, kabanos, and higurashi tea; pan-fried non-fermented tea such as yabukita tea, aoyanagi tea, and various Chinese teas; semi-fermented tea such as hojicha, tieguanyin tea, and oolong tea; and fermented tea such as black tea, abo bancha, kishiguri tea, and pu-erh tea. Non-fermented tea and semi-fermented tea having a fresh and rich aroma are particularly preferred. The tea can be in a non-dried, dried or frozen state, and can be cut or pulverized to improve the extraction efficiency. As common knowledge, the above-mentioned teas each contain about 25% or more of protein, which can be decomposed by the combination of tannase and protease, thereby producing an extract having a fresh and rich aroma.

[0028] The gardenia fruit is not particularly limited, but is preferably a wild or cultivated gardenia fruit, or a commercially available gardenia fruit. The gardenia fruit can be produced in China, Japan, etc., and is preferably a gardenia fruit produced in Zhejiang Province and Guangxi Zhuang Autonomous Region of China. As common knowledge, the gardenia fruit contains crocin, crocetin and iridoid glycoside (gardenoside) as yellow pigment components, and the gardenoside can be combined with the protein degradation product treated with β-glucosidase to produce a blue pigment, and can be combined with the protein degradation product treated with esterase to produce a red pigment. The gardenia fruit can be in a non-dried, dried or frozen state, and can be cut or pulverized to improve the extraction efficiency. In addition, the gardenia contains about 7% of protein, which can be decomposed by protease treatment to produce amino acids and peptides.

[0029] The enzyme used in the present application is not particularly limited, and any enzyme having tannase activity can be used. Specifically, the following can be exemplified: a tannase-producing fungus belonging to the genera Aspergillus, Penicillium, Rhizopus, Mucor, etc., a substance obtained by subjecting the culture of these filamentous fungi to solid culture and liquid culture according to the conventional method using a culture medium for culturing these filamentous fungi, and then purifying the obtained culture or a treated product thereof according to the conventional method. Commercially available tannases such as Tannase KT05D (produced by Kikkoman Biochemifa Company), Tannase (produced by Sanryo Co., Ltd.), and Sumizyme TAN (produced by Shin Nippon Chemical Co., Ltd.) can also be used. The amount of tannase used depends on its potency, etc., and cannot be generalized, and for example, it can be used in the range of 0.1 to 50 U / g based on the weight of the tea material.

[0030] The temperature conditions under which the tannase acts can be appropriately set within the temperature range in which the tannase acts, for example, about 30 to 60°C, preferably about 40 to 50°C. In addition, the pH conditions under which the tannase acts can be appropriately set within the pH range in which the tannase acts, for example, pH about 4.5 to 7.2, preferably pH about 4.8 to 6.5. Furthermore, the time during which the tannase acts can be appropriately set depending on the amount of tannase or tannin used, the temperature conditions, etc., for example, about 0.5 to 24 hours, preferably about 1 to 16 hours.

[0031] The protease used in the present application is not particularly limited, and at least one protease derived from an animal, a plant, and a microorganism can be used, for example, Protease A, Protease M, Protease P, Umamizyme, Peptidase R, Newlase A, Newlase F (all of which are derived from Aspergillus oryzae and are produced by Amano Enzyme Inc.); Sumizyme AP, Sumizyme LP, Sumizyme MP, Sumizyme FP, Sumizyme LPL (all of which are derived from Aspergillus oryzae and are produced by Shin Nippon Rika Co., Ltd.); Protease FN (derived from Aspergillus oryzae and produced by Wakodo Co., Ltd.); Denapsin 2P, Denazyme AP, XP-415 (all of which are derived from Aspergillus oryzae and are produced by Nagase Chemtex Corporation); Orientase 20A, Orientase ON S, Tetolase S (all of which are derived from Aspergillus oryzae and are produced by HANKYU Bioindustry Co., Ltd.); Sakanase F, PD enzyme, IP enzyme, AO-protease (all of which are derived from Aspergillus oryzae and are produced by Kikkoman Biochemifa Company); Sakanase (derived from Aspergillus oryzae and produced by Kyowa Hakko Kogyo Co., Ltd.); Panchdase YP-SS, Panchdase NP-2, Panchdase P (all of which are derived from Aspergillus oryzae and are produced by Yakult Honsha Co., Ltd.); Flavourzyme (derived from Aspergillus oryzae and produced by Novo Nordisk Bioindustry Co., Ltd.); kokulase SS, kokulase P (all of which are derived from Aspergillus oryzae and are produced by San-Ei Gen F.F.I., Inc.); VERON PS, COROLASE PN-L (all of which are derived from Aspergillus oryzae and are produced by ROEHM Enzyme Co.); Protease N, Protease NL, Protease S, Proleather FG-F (all of which are derived from Aspergillus oryzae and are produced by Amano Enzyme Inc.Protease, Protease N, Protease P, Deskin, Depilase, Protease A, ThermoASE (all of which are bacterial-derived proteases manufactured by Takara Shuzo Co., Ltd.), Bioprase XL-416F, Bioprase SP-4FG, Bioprase SP-15FG (all of which are bacterial-derived proteases manufactured by Nagase ChemteX Corporation), Directional Enzyme 90N, Nucleicin, Directional Enzyme 10NL, Directional Enzyme 22BF (all of which are bacterial-derived proteases manufactured by HANKYU Bioindustry Co., Ltd.), Aroase AP-10 (bacterial-derived protease manufactured by Yakult Honsha Co., Ltd.), Protease Complex, Neutral Protease, Alkaline Protease (all of which are bacterial-derived proteases manufactured by Novo Nordisk Bioindustry Co., Ltd.), COROLASE N, COROLASE 7089, VERON W, VERON P (all of which are bacterial-derived proteases manufactured by ROEHM Enzyme Co., Ltd.), ENZYLON NBS (bacterial-derived protease manufactured by Rokuo Kasei Co., Ltd.), Alkaline Protease GL440, Purafect 4000L, Protease 899, Protex 6L (all of which are bacterial-derived proteases manufactured by Kyowa Enzyme Co., Ltd.), Pronase AS, Pronase AF (all of which are actinomycete-derived proteases manufactured by Kyowa Hakko Kogyo Co., Ltd.), Tasinase (actinomycete-derived protease manufactured by Kyowa Enzyme Co., Ltd.), Papain W-40 (plant-derived protease manufactured by Amano Enzyme Inc.), Food Grade Purified Papain (plant-derived protease manufactured by Nagase ChemteX Corporation), and other animal-derived pepsin and trypsin, etc. The amount of protease used depends on its potency, etc., and cannot be generalized, and for example, can be in the range of 0.01 to 100 U / g based on the weight of the tea material.

[0032] The temperature conditions under which the protease acts can be appropriately set within the temperature range under which the protease acts, for example, about 30 to 60°C, preferably about 40 to 50°C. In addition, the pH conditions under which the protease acts can be appropriately set within the pH range under which the protease acts, for example, pH about 4.0 to 7.5, preferably pH about 4.5 to 6.3. Furthermore, the time under which the protease acts can be appropriately set depending on the amount of protease or protein used, the temperature conditions, etc., for example, about 0.5 to 24 hours, preferably about 1 to 16 hours.

[0033] The β-glucosidase used in the present application is not particularly limited as long as it is an enzyme having β-glucosidase activity, such as an enzyme derived from Aspergillus niger, Trichoderma reesei, Trichoderma viride, almond, and the like. Commercially available enzymes having β-glucosidase activity can also be used. Examples of commercially available enzymes having β-glucosidase activity include Sumizyme C6000, Sumizyme AC, Sumizyme C, Sumizyme X, Sumizyme BGT, and Sumizyme BGA (manufactured by Shin Nihon Chemical Co., Ltd.), Cellulosin AC40, Cellulosin T3, and Cellulosin AL (manufactured by HBI Co., Ltd.), Onozuka 3S, Y-NC (manufactured by Yakult Pharmaceutical Industry Co., Ltd.), Aromase H2, Cellulase A "Amano" 3, and Cellulase T "Amano" 4 (manufactured by Amano Enzyme Inc.), and β-glucosidase [FDY-2242] (manufactured by Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.), and the like.

[0034] The temperature conditions under which the β-glucosidase acts can be appropriately set within the temperature range in which the β-glucosidase acts, such as about 30 to 60°C, preferably about 40 to 50°C. In addition, the pH conditions under which the β-glucosidase acts can be appropriately set within the pH range in which the β-glucosidase acts, such as a pH of about 3.5 to 7.0, preferably a pH of about 4.3 to 6.6. Furthermore, the time during which the β-glucosidase acts can be appropriately set depending on the amount of β-glucosidase or geniposide used, the temperature conditions, and the like, such as about 0.5 to 15 hours, preferably about 1 to 5 hours.

[0035] In one embodiment of the present application, gardenia is mixed with tea raw material in a range of 95:5 to 5:95, 8 to 50 parts by weight of water is added to 1 part by weight of the mixed raw material, sterilized at about 60 to about 121°C for about 2 seconds to about 20 minutes, and then cooled. The tannase and protease described above are added, and enzyme treatment is performed at about 20 to about 60°C for about 30 minutes to about 24 hours. After the enzyme treatment, β-glucosidase is further added, and enzyme treatment is performed at about 20 to about 60°C for about 30 minutes to about 15 hours. Then, the enzyme is inactivated at about 60 to about 121°C for about 2 seconds to about 20 minutes, and then cooled. The solid matter is removed by centrifugation, filtration with filter paper, or the like. Then, the yellow pigment component crocin and safflor yellow acid are removed by adsorption with PVPP in an amount of 1 to 50% by weight of the gardenia raw material used. The remaining amount of the yellow pigment is adjusted, and the color of the tea extract is arbitrarily adjusted to yellow-green to blue. After the process, the solid matter is removed by centrifugation and filtration with filter paper, or the like. Thus, a clear tea extract is obtained. The gardenia • tea extract thus obtained can be concentrated as needed.

[0036] The gardenia • tea extract of the present application is generally used as it is in a beverage or the like. However, if necessary, an aromatic component such as an aromatic distillate, an aromatic extract, or a spice, and a taste component such as a taste extract or an amino acid can be added to prepare a color, aroma, and taste-enhanced extract. In addition, the tea extract of the present application is generally used in a liquid form. However, if necessary, the extract can be powdered by adding an excipient such as dextrin, processed starch, cyclodextrin, or gum arabic.

[0037] The tea extract of the present application thus obtained can be sterilized by heating after or before being filled into a container. More preferably, the extract is sterilized by heating at a high temperature for a short time using a heat exchanger, and then frozen and stored in a cold or frozen state. Thus, the tea extract of the present application can be kept in a bright green to blue color for a long period of time. DETAILED DESCRIPTION

[0038] The present application will be described in more detail by way of examples and comparative examples.

[0039] In the following examples: The green tea (powdered) had a water content of 10% or less.

[0040] The gardenia fruit was dried, and had a water content of about 5.0%.

[0041] The tannase KT05D (produced by Kikkoman Biochemifa Company) had an enzyme activity of 5,000 U / g. The protease M (produced by Amano Enzyme Inc.) had an enzyme activity of 40,000 U / g. Sumizyme AC, enzyme activity 4,000 U / g

[0042] Example 1, a preparation method of Gardenia • Tea extract, the following steps are sequentially performed: 1), Gardenia fruits produced in Zhejiang Province 20 g and Longjing green tea tea leaves (powder) produced in Hangzhou City, Zhejiang Province 80 g are mixed to prepare a mixed raw material. 100 g of the mixed raw material is added to 1000 g of soft water heated to 90°C, and stirred at 90°C for 15 minutes.

[0043] 2), the product of step 1) is cooled to 45°C, and the pH value is adjusted to 6.0 with 1M sodium bicarbonate; 0.08 g of tannase KT05D (produced by Kikkoman Biochemifa Company) is added, then 0.2 g of protease M (produced by Amano Enzyme Inc.) is added, and a first enzyme reaction is performed at 45°C for 4 hours.

[0044] Subsequently, 0.5 g of Sumizyme AC is added as a β-glucosidase, and a second enzyme reaction is performed at 45°C for 4 hours.

[0045] 3), the product of step 2) is centrifuged (8000 rpm x 20 minutes) to remove the solid components, and about 800 g of enzyme reaction liquid is obtained.

[0046] The enzyme reaction liquid is heated at 90°C for 15 minutes to inactivate the enzyme. Subsequently, it is cooled to 30°C, 10 g of polyvinylpyrrolidone (PVPP: produced by Boai Xin Kaiyuan Pharmaceutical Co., Ltd.) is added, and slowly stirred at 30°C for 15 minutes, then filtered with filter paper to obtain a clear liquid. The solution is sterilized by heating at 95°C for 15 minutes to obtain Gardenia • Tea extract 1. Subsequent aseptic filling is performed as a product.

[0047] That is, in this Example 1, the weight ratio of polyvinylpyrrolidone / Gardenia fruits = 50%.

[0048] Example 2, a preparation method of Gardenia • Tea extract, the following steps are sequentially performed: 1), Gardenia fruits produced in Zhejiang Province 50 g and Longjing green tea tea leaves (powder) produced in Hangzhou City, Zhejiang Province 50 g are mixed to prepare a mixed raw material. 100 g of the mixed raw material is added to 1000 g of soft water heated to 90°C, and stirred at 90°C for 15 minutes.

[0049] 2) ) The product obtained in step 1) was cooled to 45°C, and the pH was adjusted to 6.0 with 1 M sodium bicarbonate. To this was added tannase KT05D (produced by Kikkoman Biochemifa Company) 0.05 g, and then protease M (produced by Amano Enzyme Inc.) 0.2 g, and a first enzyme reaction was carried out at 45°C for 4 hours.

[0050] Subsequently, Sumizyme AC 0.5 g was further added as β-glucosidase, and a second enzyme reaction was carried out at 45°C for 4 hours.

[0051] 3) ) The same as step 3) of Example 1, to obtain Gardenia • tea extract 2.

[0052] Namely, in this Example 2, the weight ratio of polyvinylpyrrolidone / Gardenia fruit = 20%.

[0053] Example 3, a method for producing a Gardenia • tea extract, the following steps were carried out in order: 1) ) Gardenia fruit produced in Zhejiang Province 80 g was mixed with Longjing green tea tea leaves (powder) produced in Hangzhou City, Zhejiang Province 20 g to prepare a mixed raw material. 100 g of this mixed raw material was added to soft water 1000 g heated to 90°C, and stirred at 90°C for 15 minutes.

[0054] 2) ) The product obtained in step 1) was cooled to 45°C, and the pH was adjusted to 6.0 with 1 M sodium bicarbonate. To this was added tannase KT05D (produced by Kikkoman Biochemifa Company) 0.02 g, and then protease M (produced by Amano Enzyme Inc.) 0.2 g, and a first enzyme reaction was carried out at 45°C for 4 hours.

[0055] Subsequently, Sumizyme AC 0.5 g was further added as β-glucosidase, and a second enzyme reaction was carried out at 45°C for 4 hours.

[0056] 3) ) The same as step 3) of Example 1, to obtain Gardenia • tea extract 3.

[0057] Namely, in this Example 3, the weight ratio of polyvinylpyrrolidone / Gardenia fruit = 12.5%.

[0058] Example 4, a method for producing a Gardenia • tea extract: The difference from Example 2 is only in step 3): the amount of polyvinylpyrrolidone was changed from 10 g to 50 g; the rest is the same as Example 2. Gardenia • tea extract 4 was obtained.

[0059] That is, in this Example 4, the weight ratio of polyvinylpyrrolidone / gardenia fruits = 100%.

[0060] Example 5, a method for preparing a gardenia • tea extract, comprising the following steps in sequence: The difference from Example 2 is that: In Step 2), the amount of tannase KT05D is changed from 0.05 g to 0.10 g, the amount of protease M is changed from 0.2 g to 0.5 g, and the first enzyme reaction time is changed from 4 hours to 8 hours. In Step 3), the amount of polyvinylpyrrolidone is changed from 10 g to 50 g. The rest is the same as Example 2. Gardenia • tea extract 5 is obtained.

[0061] That is, in this Example 5, the weight ratio of polyvinylpyrrolidone / gardenia fruits = 100%.

[0062] Comparative Example 1, a method for preparing a gardenia • tea extract, comprising the following steps in sequence: 1) 3 g of gardenia fruits produced in Zhejiang Province and 97 g of Longjing green tea leaves (powder) produced in Hangzhou City, Zhejiang Province are mixed to prepare a mixed raw material. 100 g of the mixed raw material is added to 1000 g of soft water heated to 90°C, and stirred at 90°C for 15 minutes.

[0063] 2) The product obtained in Step 1) is cooled to 45°C, and the pH value is adjusted to 6.0 with 1M sodium bicarbonate. Then, 0.08 g of tannase KT05D (produced by Kikkoman Biochemifa Company) is added, followed by the addition of 0.2 g of protease M (produced by Amano Enzyme Inc.), and a first enzyme reaction is carried out at 45°C for 4 hours.

[0064] Subsequently, 0.5 g of Sumizyme AC is further added as a β-glucosidase, and a second enzyme reaction is carried out at 45°C for 4 hours.

[0065] 3) The same as Step 3) of Example 1, gardenia • tea extract 6 is obtained.

[0066] That is, in this Comparative Example 1, the weight ratio of polyvinylpyrrolidone / gardenia fruits = 333.3%.

[0067] Comparative Example 2, a method for preparing a gardenia • tea extract, comprising the following steps in sequence: The difference from Comparative Example 1 is only that "3 g of gardenia fruits + 97 g of Longjing green tea leaves" is changed to "97 g of gardenia fruits + 3 g of Longjing green tea leaves"; The rest is the same as Comparative Example 1; gardenia • tea extract 7 is obtained.

[0068] That is, in this Comparative Example 2, the weight ratio of polyvinylpyrrolidone / gardenia fruit = 10.3%.

[0069] Experiment 1, color measurement of the extract The gardenia • tea leaf extract obtained in the above Examples and Comparative Examples was diluted 1000-fold with ion exchange water to prepare a test sample for measurement. The color of the test sample was measured using a spectrophotometer (U-9000 type, Hitachi High-Technologies Corporation). The measurement conditions were as follows: the absorbance at a measurement wavelength (λ) of 605 nm and a wavelength (λ) of 480 nm was measured, and the ratio of the respective absorbance values (λ605, λ480) (λ605 / λ480) was used as an index of color. The higher this value (λ605 / λ480) is, the lighter the yellow color is, and the closer the liquid color is to blue. For example, in the case of a commercially available gardenia blue pigment, this value is 105.9, while in the case of a commercially available gardenia yellow pigment, it is 0.05. In addition, in the case of a commercially available gardenia green pigment, it is 2.56.

[0070] Color measurement results The gardenia • tea leaf extract obtained in Examples 1 to 5 and Comparative Examples 1 to 2 was diluted 1000-fold and measured using the above color measurement method to calculate (λ605 / λ480). Commercially available gardenia yellow, blue, and green pigments were diluted with ion exchange water and measured in the same manner as the color index. The results are shown in Table 1.

[0071] Experiment 2, sensory evaluation (visual evaluation) The gardenia • tea leaf extract obtained in Examples 1 to 5 and Comparative Examples 1 to 2 was diluted 400-fold and evaluated visually for color by 5 experienced evaluators. The evaluation criteria were as follows: 5. greenish blue close to blue; 4. greenish blue (turquoise) with a slight blue tint; 3. pure green; 2. bright green with a slight yellow tint; 1. yellowish green.

[0072] The average values of the 5 evaluators were calculated. The results are shown in Table 1.

[0073] Table 1 Color measurement and sensory evaluation results of gardenia • tea leaf extract

[0074] As can be seen from Table 1, Examples 1 to 5 are in the range of yellowish green to turquoise blue, Comparative Example 1 is yellowish green close to yellow, and Comparative Example 2 is blueish green close to blue.

[0075] Experiment 3, heat resistance test The gardenia • tea leaf extracts obtained in Examples 1 to 5 and Comparative Examples 1 to 2 were heated under UHT sterilization conditions (132°C, 30 seconds), and after cooling to 30°C, diluted 1000 times with ion exchange water, and measured by the color measurement method of Experiment 1 above, and (λ605 / λ480) was calculated. Then, the tea leaf extracts were diluted 400 times with ion exchange water, and the color was visually evaluated by 5 experienced judges according to the method of Experiment 2 above. The results are shown in Table 2.

[0076] Table 2: Color measurement and sensory evaluation results of gardenia • tea leaf extracts after heating at 132°C for 30 seconds

[0077] From Table 2, it can be seen that after the heat resistance experiment, Examples 1 to 5 were still in the range of yellow-green to sea blue, while Comparative Example 1 changed to yellow (orange) containing red, and Comparative Example 2 changed to blue-green containing red. It is shown that the heat resistance of Comparative Examples 1 and 2 is not as good as Examples 1 to 5 of the present application.

[0078] Experiment 4, light resistance test The gardenia • tea leaf extracts obtained in Examples 1 to 5 and Comparative Examples 1 to 2 were sterilized by UHT (132°C, 30 seconds), and then aseptically filled into transparent plastic bottles. The filled plastic bottles were placed in a light irradiation test machine LC-QHX-180F (produced by Licheng Technology Co., Ltd.) at 30°C, and irradiated with light for 168 hours continuously under 6000 lux conditions. The tea leaf extracts were diluted 1000 times with ion exchange water, and measured by the color measurement method of Experiment 1, and (λ605 / λ480) was calculated. Then, the tea leaf extracts were diluted 400 times with ion exchange water, and the color was visually evaluated by 5 experienced judges according to Experiment 2. The results are shown in Table 3.

[0079] Table 3: Color measurement and sensory evaluation results of gardenia • tea leaf extracts after light irradiation for 168 hours under 6000 lux conditions

[0080] From Table 3, it can be seen that after the light resistance experiment, Examples 1 to 5 were still in the range of yellow-green to sea blue, while Comparative Example 1 changed to yellow (orange) containing red, and Comparative Example 2 changed to blue-green containing red. It is shown that the light resistance of Comparative Examples 1 and 2 is not as good as Examples 1 to 5 of the present application.

[0081] As described above, the extract of gardenia and tea obtained by the method of the present embodiment shows blue-green from bright yellow-green in appearance without red, and its color tone does not change in the abuse test using heat or light. In contrast, Comparative Example 1 changes from a color close to yellow to yellow (orange) containing red through the abuse test using heat or light. Furthermore, Comparative Example 2 also changes to blue-green containing red. Therefore, the extract of gardenia and tea obtained by the preparation method of the present embodiment is resistant to heat and light, has little color change even if stored for a long time, and shows bright green to blue.

[0082] Comparative Example 3, in comparison with Example 2, was changed as follows: Step 2) was changed to: tannase KT05D, protease M, Sumizyme AC were added at one time and reacted at 45°C for 4 hours, 6 hours, and 8 hours, respectively. The rest was identical to Example 2.

[0083] Comparative Example 4, Example 2 was changed as follows: "Polyvinylpyrrolidone" was changed to diatomite, and the amount used was kept unchanged, and the rest was identical to Example 2.

[0084] Comparative Example 5, Example 2 was changed as follows: "Polyvinylpyrrolidone" was changed to activated carbon (GW-H; Kao Corporation (Shanghai) Limited), and the amount used was kept unchanged, and the rest was identical to Example 2.

[0085] Table 4 Color measurement of gardenia and tea extract (λ 605 nm / λ 480 nm)

[0086] In Comparative Example 3, by allowing the three enzymes to react at the same time, the respective reactions were hindered, and thus the production of blue pigment was inhibited Comparative Example 4 is not as resistant to heat and light as the present embodiment. Comparative Example 5 cannot obtain the yellow-green to sea-blue color required by the present embodiment.

[0087] Finally, it should be noted that the above only lists several specific embodiments of the present embodiment. Obviously, the present embodiment is not limited to the above embodiments, and many variations can be made. All variations that can be directly derived or inferred by those skilled in the art from the disclosure of the present embodiment should be considered as falling within the scope of the present embodiment.

Claims

1. A method for preparing Gardenia • Tea leaf extract, characterized by comprising the following steps: The application discloses a preparation method of gardenia tea extract. ​ 2. The method of claim 1, wherein the preparation of the gardenia • tea leaf extract is characterized by: The method comprises the following steps: 1) mixing gardenia fruits and tea leaves to obtain mixed raw materials, wherein the weight content of the tea leaves in the mixed raw materials is 5-95%; adding water to the mixed raw materials at 90±10 DEG C and stirring for 15±5 minutes; the weight ratio of the mixed raw materials to water is 1:8-12; 2) cooling the obtained product in step 1) to an enzymolysis temperature, adjusting the pH value to 4.5-7.2, adding tannase and protease, and performing a first enzymolysis reaction at the enzymolysis temperature for 0.5-24 hours; the weight ratio of the tannase to the mixed raw materials is 100-500 U / 100 g, and the weight ratio of the protease to the mixed raw materials is 7000-9000 U / 100 g; then, adding β-glucosidase, and performing a second enzymolysis reaction at the enzymolysis temperature for 0.5-15 hours; the weight ratio of the β-glucosidase to the mixed raw materials is 800-2500 U / 100 g; the enzymolysis temperature is 30-60 DEG C; 3) separating the obtained product in step 2); the separated liquid is an enzymolysis reaction liquid; adding polyvinylpyrrolidone with a weight of 10%-100% of the gardenia fruits to the enzymolysis reaction liquid, slowly stirring at 30±5 DEG C for 15±5 minutes, and then filtering with filter paper; the obtained filtrate is the gardenia tea extract.

3. The preparation method of the gardenia tea extract according to claim 2, wherein in step 2), the pH value is adjusted by using 1M sodium bicarbonate.

4. The preparation method of the gardenia tea extract according to claim 3, wherein the tea leaves are non-fermented tea, semi-fermented tea or fermented tea.

5. The gardenia tea extract prepared by any one of the methods in claims 1-4. A plurality of gardenia tea extracts as claimed in claim 5 are mixed to obtain food-grade pigments with yellow-green to blue colors. ​ 6. A food grade pigment characterized in that: ​

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