A method for preparing colorless tea drink without tea polyphenols and theophylline

Abstract

The invention relates to a method for preparing a colorless tea drink without tea polyphenols and theophylline, and belongs to the technical field of tea drinks. The method of the invention uses tea leaves and water as raw materials, and obtains tea water after the tea leaves are leached with water. The tea water adopts active adsorption to remove pigments, and adopts modified AB‑8 macroporous polystyrene type non-polar adsorption resin and XAD‑2 macroporous adsorption resin to obtain aroma substances by step-by-step adsorption, and the aroma substances do not contain tea polyphenols and theophylline. The colorless and odorless tea liquid after adsorption is rapidly aged at high temperature and high pressure, and then negative pressure distillation is performed to obtain a distillate with tea polyphenols and theophylline removed. The distillate is compounded with the aroma substances to obtain a tea drink. The method is a colorless, tea polyphenol-free and theophylline-free refreshing tea drink, which is conducive to sleep, reduces gastrointestinal damage, and provides consumers with more diverse choices.

Description

Technical Field

[0001] The invention belongs to the technical field of tea beverages, and in particular relates to a method for preparing a colorless tea beverage without tea polyphenols or theophylline. Background Art

[0002] Tea, as a long-standing and popular drink, has rich historical and cultural connotations. Tea polyphenols in tea have significant antioxidant properties and can neutralize free radicals in the body, which is of great significance for preventing aging and various chronic diseases. However, tea polyphenols are not only beneficial. For people with sensitive stomachs, tea polyphenols can irritate the gastrointestinal mucosa, causing symptoms such as stomach discomfort, acid reflux and even vomiting. Moreover, tea polyphenols can affect the absorption of certain minerals, such as iron and calcium, to a certain extent, which may bring potential health problems to people who already have mineral deficiencies. Theophylline, as another important ingredient in tea, belongs to the methyl purine class of drugs. It can stimulate the central nervous system, improve alertness and attention, and make people feel refreshed. But this characteristic can also have negative effects. For people with neurasthenia or insomnia, the excitatory effect of theophylline can disrupt their sleep patterns, leading to problems such as difficulty falling asleep, shallow sleep or dreaming. In addition, theophylline may also affect the cardiovascular system. For people with weak heart function or cardiovascular disease, the intake of theophylline can cause discomfort symptoms such as tachycardia and palpitations.

[0003] As people pay more attention to health and individuals react differently to tea ingredients, the demand for tea without tea polyphenols and theophylline is gradually emerging. On the one hand, some special groups, such as pregnant women, breastfeeding women, children, and patients with specific diseases (such as gastrointestinal diseases, cardiovascular diseases, sleep disorders, etc.), need to avoid the potential risks brought by tea polyphenols and theophylline. On the other hand, even healthy people may want to choose tea without stimulant ingredients in certain specific situations, such as when it is close to bedtime, to avoid affecting sleep quality.

[0004] This requires providing consumers with more diverse tea choices and pushing the tea industry towards a more refined and personalized direction. Summary of the invention

[0005] In view of the above-mentioned technical problems of tea polyphenols and theophylline in existing tea drinks, it is necessary to provide consumers with more diverse tea drink choices. The present invention provides a method for preparing colorless tea drinks without tea polyphenols and theophylline. The pigment is removed from tea water by active adsorption. AB-8 macroporous polystyrene non-polar adsorption resin column and XAD-2 macroporous adsorption resin column are used to obtain aroma substances by step-by-step adsorption. The aroma substances do not contain tea polyphenols and theophylline. The colorless and odorless tea liquid after adsorption is rapidly aged at high temperature and high pressure, and then negative pressure distillation is performed to obtain a distillate from which tea polyphenols and theophylline are removed. The distillate is compounded with aroma substances to obtain a tea drink. The tea drink is a colorless, tea polyphenol-free and theophylline-free refreshing tea drink that helps sleep, reduces gastrointestinal damage, and provides consumers with more diverse choices. The specific technical scheme is as follows:

[0006] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0007] S1, Extraction:

[0008] Extracting tea leaves with water to obtain an extract;

[0009] S2, decolorization:

[0010] The extract is decolorized by an activated carbon column to obtain a colorless tea liquid;

[0011] S3, deodorization:

[0012] Passing the colorless tea liquid at 10°C to 15°C through an AB-8 macroporous polystyrene non-polar adsorption resin column at a speed of 5BV / h to 10BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0013] S4: The AB-8 macroporous polystyrene non-polar adsorption resin column is eluted with an aqueous NaOH solution to obtain a primary eluent, and the pH of the primary eluent is adjusted to 6.5-7 with an aqueous hydrochloric acid solution; the primary eluent at 10°C-15°C is passed through a XAD-2 macroporous adsorption resin column at a rate of 5BV / h-10BV / h to intercept aroma substances again, and the XAD-2 macroporous adsorption resin column is eluted with an aqueous NaOH solution to obtain a secondary eluent, and the pH of the secondary eluent is adjusted to 6.5-7 with an aqueous hydrochloric acid solution, and finally freeze-dried to obtain aroma substances;

[0014] The AB-8 macroporous polystyrene non-polar adsorption resin column is filled with AB-8 macroporous polystyrene non-polar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0015] S5: boiling the colorless and odorless tea liquid obtained in S3 in a high temperature and high pressure furnace to obtain the boiled colorless and odorless tea liquid, cooling the temperature to 90° C., and distilling the boiled colorless and odorless tea liquid in a negative pressure distillation furnace until it is evaporated to dryness, and cooling the steam to form a distillate;

[0016] S6, compound:

[0017] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0018] In S1 of the above preparation method, the specific method of the leaching is:

[0019] Add tea leaves into water to obtain a mixed solution in a mass ratio of tea leaves to water = 1: (10-30); extract the mixed solution at a constant temperature of 75° C. to 95° C. in a water bath for 30 min to 180 min, and filter to obtain an extract.

[0020] In S2 of the above preparation method, the specific method of decolorization is:

[0021] The extract at 40°C to 50°C is passed through an activated carbon column at a speed of 8BV / h to 15BV / h to decolorize and obtain colorless tea liquid.

[0022] In S4 of the above preparation method, the concentration of the NaOH aqueous solution is 5wt% to 8wt%.

[0023] In S4 of the above preparation method, the concentration of the aqueous hydrochloric acid solution is 0.8 mol / L to 1.2 mol / L.

[0024] In S4 of the above preparation method, the pore size of the AB-8 macroporous polystyrene non-polar adsorption resin is 12nm~16nm; the modification method of the AB-8 macroporous polystyrene non-polar adsorption resin is: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: (0.02~0.05): (0.005~0.01), oligofructose and oligogalactose are dissolved in water to obtain an infusion; according to the volume ratio, AB-8 macroporous polystyrene non-polar adsorption resin: infusion = 1: (5~10), the AB-8 macroporous polystyrene non-polar adsorption resin is placed in the infusion, stirred and mixed for more than 5min, filtered, the AB-8 macroporous polystyrene non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene non-polar adsorption resin modified with oligofructose and oligogalactose.

[0025] In S4 of the above preparation method, the pore size of the XAD-2 macroporous adsorption resin is 9 nm; the modification method of the XAD-2 macroporous adsorption resin is: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: (0.02 ~ 0.05): (0.005 ~ 0.01), oligofructose and oligogalactose are dissolved in water to obtain an infusion; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion = 1: (5 ~ 10), the XAD-2 macroporous adsorption resin is placed in the infusion, stirred and mixed for more than 5 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0026] In S4 of the above preparation method, the molecular weight of the fructooligosaccharide is between 300Da and 1000Da; the molecular weight of the galacto-oligosaccharide is between 500Da and 1000Da.

[0027] In S5 of the above preparation method, the parameters of the high temperature and high pressure furnace cooking are: pressure of 0.2MPa to 0.5MPa, temperature of 120°C to 150°C, and time of 10min to 20min.

[0028] In S5 of the above preparation method, the cooling temperature is 70°C to 90°C.

[0029] In S5 of the above preparation method, the parameters of the distillation in the negative pressure distillation furnace are: pressure of 70 kPa to 90 kPa, and temperature of 70° C. to 90° C.

[0030] The method for preparing a colorless tea beverage without tea polyphenols and theophylline provided by the present invention has the following beneficial effects compared with the prior art:

[0031] 1. The method of the present invention adopts AB-8 macroporous polystyrene non-polar adsorption resin column and XAD-2 macroporous adsorption resin column to purify aroma substances twice, which can effectively filter out tea polyphenols and theophylline in tea leaves. AB-8 macroporous polystyrene non-polar adsorption resin and XAD-2 macroporous adsorption resin are repellent to tea polyphenols and theophylline, and can effectively reduce the residual amount of tea polyphenols and theophylline in aroma substances. In the subsequent compounding, tea polyphenols and theophylline will not be introduced.

[0032] 2. The method of the present invention uses a high-temperature and high-pressure furnace to steam the colorless and odorless tea liquid, which can achieve accelerated aging and accelerate the aging of the components that are not adsorbed by the activated carbon and the resin column to obtain a unique taste.

[0033] 3. The method of the present invention adopts a negative pressure distillation furnace to distill the colorless and odorless tea liquid. On the one hand, the negative pressure distillation will not cause secondary high-temperature destruction to the product. On the other hand, it can well distill and separate low-boiling point substances, so that the obtained distillate does not contain tea polyphenols and theophylline; after compounding and mixing with aroma substances, the zero content of tea polyphenols and theophylline is guaranteed.

[0034] 4. The adsorption flow rate of AB-8 macroporous polystyrene non-polar adsorption resin column and XAD-2 macroporous adsorption resin column is 5BV / h~10BV / h. The setting of this flow rate can, on the one hand, well ensure the adsorption amount of aroma substances, and on the other hand, well purify and remove tea polyphenols and theophylline in aroma substances.

[0035] 5. Fructooligosaccharides and galactoligosaccharides are small molecular water-soluble viscous substances. AB-8 macroporous polystyrene non-polar adsorption resin and XAD-2 macroporous adsorption resin are modified with fructooligosaccharides and galactoligosaccharides in a certain proportion, so that fructooligosaccharides and galactoligosaccharides adhere to the pore walls of the resin to form a film. When encountering tea leaves, the film has a certain viscosity when it comes into contact with water, and has better selectivity for aroma substances. It can adsorb aroma substances more quickly and stably, reduce the pore size, and has better rejection of tea polyphenols and theophylline; thus, it can better purify aroma substances and make the residual amount of tea polyphenols and theophylline in the aroma substances reach undetectable level.

[0036] 6. Fructooligosaccharides and galacto-oligosaccharides can be eluted together with aroma substances and incorporated into the aroma substances. After being compounded into tea drinks, they play a certain role in regulating intestinal flora, promoting digestion, and lowering cholesterol.

[0037] 7. The present invention uses activated carbon to effectively remove pigments in tea drinks, thereby preparing colorless tea drinks.

[0038] 8. The method for preparing colorless tea drinks without tea polyphenols and theophylline of the present invention can effectively remove tea polyphenols and theophylline in tea drinks, fill in natural aroma substances, and retain other beneficial ingredients and unique flavors in tea drinks. The preparation of colorless, tea polyphenol-free and theophylline-free refreshing tea drinks can help sleep, reduce gastrointestinal damage, provide consumers with more diverse choices, and also promote the development of the tea drink industry in a more refined and personalized direction. DETAILED DESCRIPTION

[0039] The present invention is further described below in conjunction with specific implementation cases, but the present invention is not limited to these embodiments.

[0040] Example 1

[0041] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0042] S1, Extraction:

[0043] The tea leaves were crushed in a mass ratio of tea leaves to water = 1:30, and then added into water to obtain a mixed solution; the mixed solution was subjected to constant temperature leaching at 95°C in a water bath for 180 minutes, and then filtered to obtain an extract;

[0044] S2, decolorization:

[0045] The 50°C extract was passed through an activated carbon column at a rate of 15 BV / h to decolorize and obtain a colorless tea liquid;

[0046] S3, deodorization:

[0047] Passing the colorless tea liquid at 15°C through an AB-8 macroporous polystyrene non-polar adsorption resin column with a pore size of 16 nm at a speed of 10 BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0048] S4: an AB-8 macroporous polystyrene non-polar adsorption resin column is eluted with an 8wt% NaOH aqueous solution to obtain a primary eluate, and the primary eluate is adjusted to pH 7 with an aqueous hydrochloric acid solution with a concentration of 1.2 mol / L; the primary eluate at 15°C is passed through a XAD-2 macroporous adsorption resin column with a pore size of 9 nm at a speed of 10 BV / h to intercept aroma substances again, and the XAD-2 macroporous adsorption resin column is eluted with an 8wt% NaOH aqueous solution to obtain a secondary eluate, and the secondary eluate is adjusted to pH 7 with an aqueous hydrochloric acid solution with a concentration of 1.2 mol / L, and finally freeze-dried to obtain aroma substances;

[0049] The AB-8 macroporous polystyrene nonpolar adsorption resin column is filled with the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0050] S5: the colorless and odorless tea liquid obtained in S3 is boiled in a high-temperature and high-pressure furnace at a pressure of 0.5 MPa and a temperature of 150° C. for 20 minutes to obtain the boiled colorless and odorless tea liquid, and after cooling to 90° C., the boiled colorless and odorless tea liquid is distilled in a negative pressure distillation furnace at a pressure of 90 kPa and a temperature of 90° C. until evaporated to dryness, and the steam is cooled to form a distillate;

[0051] S6, compound:

[0052] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0053] Among them, the modification method of AB-8 macroporous polystyrene type non-polar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.03: 0.008, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, AB-8 macroporous polystyrene type non-polar adsorption resin: infusion solution = 1:8, AB-8 macroporous polystyrene type non-polar adsorption resin is placed in the infusion solution, stirred and mixed for 8 minutes, filtered, the AB-8 macroporous polystyrene type non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene type non-polar adsorption resin modified with oligofructose and oligogalactose.

[0054] Among them, the modification method of XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.03: 0.008, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion solution = 1:8, XAD-2 macroporous adsorption resin is placed in the infusion solution, stirred and mixed for 8 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0055] Example 2

[0056] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0057] S1, Extraction:

[0058] According to the mass ratio of tea leaves to water = 1:25, tea leaves are added to water to obtain a mixed solution; the mixed solution is subjected to constant temperature extraction in a 90°C water bath for 150 minutes, and an extract is obtained by filtering;

[0059] S2, decolorization:

[0060] The extract at 48°C was passed through an activated carbon column at a rate of 12 BV / h to decolorize and obtain a colorless tea liquid;

[0061] S3, deodorization:

[0062] Passing the colorless tea liquid at 14°C through an AB-8 macroporous polystyrene non-polar adsorption resin column with a pore size of 15 nm at a speed of 8 BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0063] S4: eluting the AB-8 macroporous polystyrene non-polar adsorption resin column with a 7wt% NaOH aqueous solution to obtain a primary eluate, adjusting the pH of the primary eluate to 6.8 with a 1.0mol / L hydrochloric acid aqueous solution; then passing the primary eluate at 14°C through a XAD-2 macroporous adsorption resin column with a pore size of 9nm at a rate of 8BV / h to intercept aroma substances again, eluting the XAD-2 macroporous adsorption resin column with a 7wt% NaOH aqueous solution to obtain a secondary eluate, adjusting the pH of the secondary eluate to 6.8 with a 1.0mol / L hydrochloric acid aqueous solution, and finally freeze-drying to obtain aroma substances;

[0064] The AB-8 macroporous polystyrene nonpolar adsorption resin column is filled with the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0065] S5: the colorless and odorless tea liquid obtained in S3 is boiled in a high-temperature and high-pressure furnace at a pressure of 0.4 MPa and a temperature of 140° C. for 18 minutes to obtain the boiled colorless and odorless tea liquid, and after cooling to 85° C., the boiled colorless and odorless tea liquid is distilled in a negative pressure distillation furnace at a pressure of 85 kPa and a temperature of 85° C. until evaporated to dryness, and the steam is cooled to form a distillate;

[0066] S6, compound:

[0067] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0068] Among them, the modification method of AB-8 macroporous polystyrene type non-polar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100:0.02:0.005, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, AB-8 macroporous polystyrene type non-polar adsorption resin: infusion solution = 1:5, AB-8 macroporous polystyrene type non-polar adsorption resin is placed in the infusion solution, stirred and mixed for 5 minutes, filtered, the AB-8 macroporous polystyrene type non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene type non-polar adsorption resin modified with oligofructose and oligogalactose.

[0069] Among them, the modification method of XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.02: 0.005, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion solution = 1:5, XAD-2 macroporous adsorption resin is placed in the infusion solution, stirred and mixed for 5 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0070] Example 3

[0071] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0072] S1, Extraction:

[0073] According to the mass ratio of tea leaves to water = 1:20, tea leaves are added to water to obtain a mixed solution; the mixed solution is subjected to constant temperature extraction in a water bath at 80°C for 90 minutes, and an extract is obtained by filtering;

[0074] S2, decolorization:

[0075] The extract at 45°C was passed through an activated carbon column at a rate of 10 BV / h to decolorize and obtain a colorless tea liquid;

[0076] S3, deodorization:

[0077] Passing the colorless tea liquid at 12°C through an AB-8 macroporous polystyrene non-polar adsorption resin column with a pore size of 14 nm at a rate of 6.5 BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0078] S4: an AB-8 macroporous polystyrene non-polar adsorption resin column is eluted with a 6.5wt% NaOH aqueous solution to obtain a primary eluate, and the primary eluate is adjusted to pH 6.6 with a 1.0mol / L hydrochloric acid aqueous solution; the primary eluate at 12°C is passed through a XAD-2 macroporous adsorption resin column with a pore size of 9nm at a rate of 6.5BV / h to intercept aroma substances again, and the XAD-2 macroporous adsorption resin column is eluted with a 6.5wt% NaOH aqueous solution to obtain a secondary eluate, and the secondary eluate is adjusted to pH 6.7 with a 1.0mol / L hydrochloric acid aqueous solution, and finally freeze-dried to obtain aroma substances;

[0079] The AB-8 macroporous polystyrene nonpolar adsorption resin column is filled with the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0080] S5: the colorless and odorless tea liquid obtained in S3 is boiled in a high-temperature and high-pressure furnace at a pressure of 0.3 MPa and a temperature of 130° C. for 15 minutes to obtain the boiled colorless and odorless tea liquid, and after cooling to 80° C., the boiled colorless and odorless tea liquid is distilled in a negative pressure distillation furnace at a pressure of 80 kPa and a temperature of 80° C. until evaporated to dryness, and the steam is cooled to form a distillate;

[0081] S6, compound:

[0082] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0083] Among them, the modification method of AB-8 macroporous polystyrene non-polar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100:0.02:0.01, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, AB-8 macroporous polystyrene non-polar adsorption resin: infusion solution = 1:5, AB-8 macroporous polystyrene non-polar adsorption resin is placed in the infusion solution, stirred and mixed for 8 minutes, filtered, the AB-8 macroporous polystyrene non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene non-polar adsorption resin modified with oligofructose and oligogalactose.

[0084] Among them, the modification method of XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.05: 0.005, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion solution = 1:10, XAD-2 macroporous adsorption resin is placed in the infusion solution, stirred and mixed for 6 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0085] Example 4

[0086] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0087] S1, Extraction:

[0088] According to the mass ratio of tea leaves to water = 1:15, tea leaves are added to water to obtain a mixed solution; the mixed solution is subjected to constant temperature extraction in a water bath at 78°C for 60 minutes, and an extract is obtained by filtering;

[0089] S2, decolorization:

[0090] The extract at 42°C was passed through an activated carbon column at a rate of 9 BV / h to decolorize and obtain a colorless tea liquid;

[0091] S3, deodorization:

[0092] Passing the colorless tea liquid at 12°C through an AB-8 macroporous polystyrene non-polar adsorption resin column with a pore size of 13 nm at a speed of 7 BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0093] S4: eluting the AB-8 macroporous polystyrene non-polar adsorption resin column with a 6wt% NaOH aqueous solution to obtain a primary eluate, adjusting the pH of the primary eluate to 6.6 with a 0.9mol / L hydrochloric acid aqueous solution; then passing the primary eluate at 12°C through a XAD-2 macroporous adsorption resin column with a pore size of 9nm at a rate of 7BV / h to intercept aroma substances again, eluting the XAD-2 macroporous adsorption resin column with a 6wt% NaOH aqueous solution to obtain a secondary eluate, adjusting the pH of the secondary eluate to 6.6 with a 0.9mol / L hydrochloric acid aqueous solution, and finally freeze-drying to obtain aroma substances;

[0094] The AB-8 macroporous polystyrene nonpolar adsorption resin column is filled with the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0095] S5: the colorless and odorless tea liquid obtained in S3 is boiled in a high-temperature and high-pressure furnace at a pressure of 0.3 MPa and a temperature of 125° C. for 12 minutes to obtain the boiled colorless and odorless tea liquid, and after cooling to 75° C., the boiled colorless and odorless tea liquid is distilled in a negative pressure distillation furnace at a pressure of 75 kPa and a temperature of 75° C. until evaporated to dryness, and the steam is cooled to form a distillate;

[0096] S6, compound:

[0097] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0098] Among them, the modification method of AB-8 macroporous polystyrene non-polar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100:0.05:0.005, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, AB-8 macroporous polystyrene non-polar adsorption resin: infusion solution = 1:10, AB-8 macroporous polystyrene non-polar adsorption resin is placed in the infusion solution, stirred and mixed for 6 minutes, filtered, the AB-8 macroporous polystyrene non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene non-polar adsorption resin modified with oligofructose and oligogalactose.

[0099] Among them, the modification method of XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.02: 0.01, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion solution = 1:5, XAD-2 macroporous adsorption resin is placed in the infusion solution, stirred and mixed for 6 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0100] Example 5

[0101] A method for preparing a colorless tea beverage without tea polyphenols and theophylline, comprising the following steps:

[0102] S1, Extraction:

[0103] According to the mass ratio of tea leaves to water = 1:10, tea leaves are added to water to obtain a mixed solution; the mixed solution is subjected to constant temperature extraction at 75°C in a water bath for 30 minutes, and an extract is obtained by filtering;

[0104] S2, decolorization:

[0105] The extract at 40°C was passed through an activated carbon column at a rate of 8 BV / h to decolorize and obtain a colorless tea liquid;

[0106] S3, deodorization:

[0107] Passing the colorless tea liquid at 10°C through an AB-8 macroporous polystyrene non-polar adsorption resin column with a pore size of 12 nm at a speed of 5 BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid;

[0108] S4: eluting the AB-8 macroporous polystyrene non-polar adsorption resin column with a 5wt% NaOH aqueous solution to obtain a primary eluate, adjusting the pH of the primary eluate to 6.5 with a 0.8mol / L hydrochloric acid aqueous solution; then passing the primary eluate at 10°C through a XAD-2 macroporous adsorption resin column with a pore size of 9nm at a rate of 5BV / h to intercept aroma substances again, eluting the XAD-2 macroporous adsorption resin column with a 5wt% NaOH aqueous solution to obtain a secondary eluate, adjusting the pH of the secondary eluate to 6.5 with a 0.8mol / L hydrochloric acid aqueous solution, and finally freeze-drying to obtain aroma substances;

[0109] The AB-8 macroporous polystyrene nonpolar adsorption resin column is filled with the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose;

[0110] S5: the colorless and odorless tea liquid obtained in S3 is boiled in a high-temperature and high-pressure furnace at a pressure of 0.2 MPa and a temperature of 120° C. for 10 min to obtain the boiled colorless and odorless tea liquid, and after cooling to 70° C., the boiled colorless and odorless tea liquid is distilled in a negative pressure distillation furnace at a pressure of 70 kPa and a temperature of 70° C. until evaporated to dryness, and the steam is cooled to form a distillate;

[0111] S6, compound:

[0112] The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

[0113] The manufacturer of the AB-8 macroporous polystyrene non-polar adsorption resin used in the above embodiments is Tianjin Bohong Resin Technology Co., Ltd.; the manufacturer of the XAD-2 macroporous adsorption resin used is Wuhan Weiqi Boxing Biotechnology Co., Ltd. The tea used is Tieguanyin.

[0114] Among them, the modification method of AB-8 macroporous polystyrene type non-polar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.05: 0.01, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, AB-8 macroporous polystyrene type non-polar adsorption resin: infusion solution = 1:10, AB-8 macroporous polystyrene type non-polar adsorption resin is placed in the infusion solution, stirred and mixed for 10 minutes, filtered, the AB-8 macroporous polystyrene type non-polar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene type non-polar adsorption resin modified with oligofructose and oligogalactose.

[0115] Among them, the modification method of XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose = 100: 0.05: 0.01, oligofructose and oligogalactose are dissolved in water to obtain an infusion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: infusion solution = 1:10, XAD-2 macroporous adsorption resin is placed in the infusion solution, stirred and mixed for 8 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose.

[0116] The molecular weight of the fructooligosaccharide used in the above embodiments is between 300Da and 1000Da; the molecular weight of the galacto-oligosaccharide is between 500Da and 1000Da.

[0117] Comparative Example 1

[0118] The colorless tea liquid does not use AB-8 macroporous polystyrene non-polar adsorption resin column to adsorb aroma substances, but directly uses XAD-2 macroporous adsorption resin column to adsorb aroma substances; other parameters and methods are the same as in Example 1.

[0119] Comparative Example 2

[0120] The colorless tea liquid only uses AB-8 macroporous polystyrene non-polar adsorption resin column to adsorb aroma substances, and does not use XAD-2 macroporous adsorption resin column to adsorb aroma substances; other parameters and methods are the same as in Example 1.

[0121] Comparative Example 3

[0122] The colorless and odorless tea liquid is not boiled in a high-temperature and high-pressure furnace, but is directly distilled in a negative pressure distillation furnace; other parameters and methods are the same as in Example 1.

[0123] Comparative Example 4

[0124] The colorless and odorless tea liquid is not distilled in a negative pressure distillation furnace; other parameters and methods are the same as in Example 1.

[0125] Comparative Example 5

[0126] The adsorption flow rates of the AB-8 macroporous polystyrene non-polar adsorption resin column and the XAD-2 macroporous adsorption resin column are both 3 BV / h; other parameters and methods are the same as in Example 1.

[0127] Comparative Example 6

[0128] XAD-4 macroporous adsorption resin column was used to replace XAD-2 macroporous adsorption resin column; other parameters and methods were the same as those in Example 1.

[0129] Comparative Example 7

[0130] AB-8 macroporous polystyrene non-polar adsorption resin and XAD-2 macroporous adsorption resin were not modified; other parameters and methods were the same as in Example 1.

[0131] Comparative Example 8

[0132] In the modification method of AB-8 macroporous polystyrene non-polar adsorption resin, the mass ratio of the immersion liquid is purified water: oligofructose: oligogalactose = 100: 0.01: 0.0028; in the modification method of XAD-2 macroporous adsorption resin, the mass ratio of the immersion liquid is purified water: oligofructose: oligogalactose = 100: 0.01: 0.028; other parameters and methods are the same as in Example 1.

[0133] Comparative Example 9

[0134] In the modification method of AB-8 macroporous polystyrene non-polar adsorption resin, the mass ratio of the immersion liquid is purified water: oligofructose: oligogalactose = 100: 0.037: 0.001; in the modification method of XAD-2 macroporous adsorption resin, the mass ratio of the immersion liquid is purified water: oligofructose: oligogalactose = 100: 0.037: 0.001; other parameters and methods are the same as in Example 1.

[0135] The tea polyphenols and theophylline contents of the tea drinks prepared in the above-mentioned embodiments and comparative examples were tested.

[0136] After the colorless tea drink without tea polyphenols and theophylline was concentrated to 20% volume, the tea polyphenol content was detected by high performance liquid chromatography (HPLC), and the theophylline content was detected by high performance liquid chromatography-mass spectrometry (HPLC-MS). The test results are shown in Table 1 below.

[0137] Table 1 Tea polyphenols and theophylline content

[0138]

[0139]

[0140] It can be seen from the above results that the tea prepared by the methods of Examples 1 to 5 does not contain tea polyphenols and theophylline, and the removal rate of tea polyphenols and theophylline is 100%. It can be seen from the results of Comparative Examples 1 and 2 that reducing the AB-8 macroporous polystyrene non-polar adsorption resin column or reducing the XAD-2 macroporous adsorption resin column will cause the aroma substances to contain a small amount of tea polyphenols and theophylline, and the purification ability of the aroma substances is poor. It can be seen from the results of Comparative Example 3 that the removal degree of tea polyphenols and theophylline is not affected by not using a high-temperature and high-pressure furnace to boil tea water, that is, the tea water is not accelerated to age. It can be seen from the results of Comparative Example 4 that the tea liquid contains a large amount of tea polyphenols and theophylline without distillation in a negative pressure distillation furnace. It can be seen from the results of Comparative Example 5 that slow adsorption will increase the adsorption amount of tea polyphenols and theophylline, thereby increasing the content of tea polyphenols and theophylline in the aroma substances. As shown in the results of Comparative Example 6, the use of XAD-4 macroporous adsorption resin column to replace XAD-2 macroporous adsorption resin column will increase the adsorption of tea polyphenols and theophylline, and the tea polyphenols and theophylline in the aroma substances have poor purification. As shown in the results of Comparative Example 7, the modified resin has better adsorption selectivity for aroma substance components, which can make the resin adsorb aroma substances more quickly, reduce the pore size, and have better rejection for tea polyphenols and theophylline. As shown in the results of Comparative Examples 8-9, in the resin modification, the ratio of oligofructose and oligogalactose is changed, and when the ratio of purified water: oligofructose: oligogalactose is not within the range of 100: (0.02-0.05): (0.005-0.01) of the present invention, the adsorption of aroma substances by the resin will be reduced, containing a small amount of tea polyphenols and theophylline.

Claims

1. A method for preparing a colorless tea drink without tea polyphenols and theophylline, characterized in that: The steps include: S1, Extraction: Extracting tea leaves with water to obtain an extract; S2, decolorization: The extract is decolorized by an activated carbon column to obtain a colorless tea liquid; S3, deodorization: Passing the colorless tea liquid at 10°C to 15°C through an AB-8 macroporous polystyrene non-polar adsorption resin column at a speed of 5BV / h to 10BV / h to intercept the aroma substances in the colorless tea liquid and obtain colorless and odorless tea liquid; S4: The AB-8 macroporous polystyrene non-polar adsorption resin column is eluted with an aqueous NaOH solution to obtain a primary eluent, and the pH of the primary eluent is adjusted to 6.5-7 with an aqueous hydrochloric acid solution; the primary eluent at 10°C-15°C is passed through a XAD-2 macroporous adsorption resin column at a rate of 5BV / h-10BV / h to intercept aroma substances again, and the XAD-2 macroporous adsorption resin column is eluted with an aqueous NaOH solution to obtain a secondary eluent, and the pH of the secondary eluent is adjusted to 6.5-7 with an aqueous hydrochloric acid solution, and finally freeze-dried to obtain aroma substances; The AB-8 macroporous polystyrene non-polar adsorption resin column is filled with AB-8 macroporous polystyrene non-polar adsorption resin modified with oligofructose and oligogalactose; the XAD-2 macroporous adsorption resin column is filled with XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose; The pore size of the AB-8 macroporous polystyrene nonpolar adsorption resin is 12nm-16nm; the modification method of the AB-8 macroporous polystyrene nonpolar adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose=100:(0.02-0.05):(0.005-0.01), oligofructose and oligogalactose are dissolved in water to obtain an immersion solution; according to the volume ratio, AB-8 macroporous polystyrene nonpolar adsorption resin: immersion solution=1:(5-10), the AB-8 macroporous polystyrene nonpolar adsorption resin is placed in the immersion solution, stirred and mixed for more than 5min, filtered, the AB-8 macroporous polystyrene nonpolar adsorption resin is taken, and dried to obtain the AB-8 macroporous polystyrene nonpolar adsorption resin modified with oligofructose and oligogalactose; The pore size of the XAD-2 macroporous adsorption resin is 9 nm; the modification method of the XAD-2 macroporous adsorption resin is as follows: according to the mass ratio, purified water: oligofructose: oligogalactose=100:(0.02-0.05):(0.005-0.01), oligofructose and oligogalactose are dissolved in water to obtain an immersion solution; according to the volume ratio, XAD-2 macroporous adsorption resin: immersion solution=1:(5-10), the XAD-2 macroporous adsorption resin is placed in the immersion solution, stirred and mixed for more than 5 minutes, filtered, the XAD-2 macroporous adsorption resin is taken, and dried to obtain the XAD-2 macroporous adsorption resin modified with oligofructose and oligogalactose; S5: boiling the colorless and odorless tea liquid obtained in S3 in a high temperature and high pressure furnace to obtain the boiled colorless and odorless tea liquid, cooling the boiled colorless and odorless tea liquid, and distilling the boiled colorless and odorless tea liquid in a negative pressure distillation furnace until it is evaporated to dryness, and cooling the steam to form a distillate; S6, compound: The aroma substances are added into the distillate, mixed and dissolved, so as to obtain a colorless tea drink without tea polyphenols and theophylline.

2. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S1, the specific method of the extraction is: Add tea leaves into water to obtain a mixed solution in a mass ratio of tea leaves to water = 1: (10-30); extract the mixed solution at a constant temperature of 75° C. to 95° C. in a water bath for 30 min to 180 min, and filter to obtain an extract.

3. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S2, the specific method of decolorization is: The extract at 40°C to 50°C is passed through an activated carbon column at a speed of 8BV / h to 15BV / h to decolorize and obtain colorless tea liquid.

4. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S4, the concentration of the NaOH aqueous solution is 5wt% to 8wt%.

5. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S4, the concentration of the hydrochloric acid aqueous solution is 0.8 mol / L to 1.2 mol / L.

6. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S4, the molecular weight of the fructooligosaccharide is between 300Da and 1000Da; the molecular weight of the galacto-oligosaccharide is between 500Da and 1000Da.

7. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S5, the parameters of the high temperature and high pressure furnace cooking are: pressure of 0.2MPa to 0.5MPa, temperature of 120°C to 150°C, and time of 10min to 20min.

8. The method for preparing a colorless tea drink without tea polyphenols and theophylline according to claim 1, characterized in that: In S5, the cooling temperature is 70°C to 90°C; the parameters of the distillation in the negative pressure distillation furnace are: pressure of 70kPa to 90kPa, and temperature of 70°C to 90°C.

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