Preparation method of tea leaves rich in tea polyphenols

Abstract

The invention relates to a preparation method of tea leaves rich in tea polyphenols, and belongs to the technical field of tea leaf preparation, the preparation method of the tea leaves rich in the tea polyphenols comprises the following steps: uniformly mixing green tea leaves and a composite infusion agent, and then rocking the green tea leaves; performing cooling and microwave fixation on the rocked tea leaves; and drying the tea leaves after fixation. By compounding pectinase and cellulase, main components forming plant cell walls such as cellulose and pectin can be decomposed, local collapse, dissolution or looseness of the cell walls are caused, and the dissolution rate of effective components is increased; the beta-cyclodextrin and the curcumin are both of a special outer-hydrophilic and inner-hydrophobic structure, fat-soluble effective components can be included, the solubility of the fat-soluble effective components is increased, the stability of tea polyphenol components is improved, and then the tea leaves are rich in tea polyphenol.

Description

Technical Field

[0001] The invention belongs to the technical field of tea preparation and relates to a method for preparing tea rich in tea polyphenols. Background Art

[0002] With the rapid development of my country's tea industry economy, the scale of tea processing and deep processing is increasing day by day. Tea polyphenols are a compound naturally formed in tea leaves, which has many health benefits. Tea polyphenols are a powerful antioxidant that can help remove free radicals in the body, thereby slowing down the aging process of cells. The content of tea polyphenols in tea varies depending on the type of tea and the processing method. Generally speaking, the content of tea polyphenols in green tea and white tea is higher. Tea polyphenols remove free radicals, delay cell aging, and reduce the risk of chronic diseases; it helps to lower blood pressure cholesterol, reduce the risk of arteriosclerosis, and protect cardiovascular health. It has anti-inflammatory properties, reduces inflammation, and relieves inflammatory diseases such as arthritis. Tea polyphenols inhibit the growth and spread of cancer cells and reduce the incidence of certain cancers. In addition, it promotes fat decomposition, improves metabolism, and helps lose weight and control weight.

[0003] In the integration of today's tea culture and modern technology, tea polyphenols, as a precious ingredient in tea, have attracted much attention for its excellent antioxidant, anti-inflammatory and anti-cancer health benefits. In order to fully tap and utilize this natural treasure, scientists continue to explore and optimize the extraction technology of tea polyphenols. At present, there are many mainstream tea polyphenol extraction methods on the market, each of which carries unique scientific wisdom and practical experience, including solvent extraction, enzyme extraction, β-cyclodextrin-assisted extraction, supercritical fluid extraction, ultrasonic extraction and microwave extraction. These technologies are like bright pearls, together forming a bright starry sky in the field of tea polyphenol extraction.

[0004] Solvent extraction, as a traditional and classic extraction method, mainly relies on the solvent's ability to dissolve tea polyphenols. By selecting a suitable solvent (such as ethanol, water, etc.) and extracting under suitable temperature and time conditions, tea polyphenols can be effectively separated from tea leaves. However, this method also faces challenges such as solvent residue and low extraction efficiency. To this end, researchers continue to optimize solvent types, ratios and extraction conditions in order to achieve higher extraction purity and yield.

[0005] Enzyme extraction is an innovative technology that uses biological enzymes to degrade tea cell walls, thereby promoting the release of tea polyphenols. The high efficiency and specificity of enzymes allow this method to reduce the generation of harmful substances while ensuring the activity of tea polyphenols. However, issues such as enzyme cost, stability, and reaction condition control still need to be further resolved.

[0006] β-cyclodextrin-assisted extraction is a green and environmentally friendly extraction strategy that has emerged in recent years. β-cyclodextrin, as a non-toxic and biodegradable cyclic oligosaccharide, can form a stable inclusion complex with tea polyphenols, thereby improving the solubility and stability of tea polyphenols. This technology not only helps to improve the extraction efficiency, but also effectively protects the biological activity of tea polyphenols.

[0007] Supercritical fluid extraction, with its unique supercritical state (i.e. the state of a substance at a temperature and pressure higher than its critical value), demonstrates extraordinary extraction capabilities. Supercritical fluids (such as supercritical carbon dioxide) have excellent solubility and permeability, and can penetrate deep into the tea leaves to extract tea polyphenols quickly and efficiently. In addition, this technology also has the advantages of being environmentally friendly, energy-saving, and easy to separate and purify, and is an important development direction in the field of tea polyphenol extraction in the future.

[0008] Ultrasonic extraction and microwave extraction are two rapid extraction technologies based on physical field effects. Ultrasonic waves can accelerate the dissolution of tea polyphenols from tea leaves through cavitation, thermal and mechanical effects; while microwaves, through their unique heating method, can rapidly heat up the inside of tea leaves, accelerating the rupture of cell walls and the release of tea polyphenols. Both technologies have the advantages of short extraction time, high efficiency and low energy consumption, but in practical applications, it is still necessary to pay attention to controlling parameters to avoid damage to tea polyphenols.

[0009] In the face of the shortcomings and limitations of a single extraction method, an innovative idea of ​​synergistic extraction is proposed. The synergistic extraction method aims to achieve efficient, high-purity, and low-energy extraction of tea polyphenols by integrating the advantages of multiple extraction technologies. For example, solvent extraction can be combined with enzyme extraction, using enzymatic hydrolysis to improve the permeability of tea cells, and then combined with the solubility of the solvent to achieve full extraction of tea polyphenols; or supercritical fluid extraction can be combined with ultrasonic extraction, using the synergistic effect of the solubility of supercritical fluid and the cavitation effect of ultrasonic waves to further improve the extraction efficiency and purity. Summary of the invention

[0010] The object of the present invention is to provide a method for preparing tea rich in tea polyphenols. The present invention can decompose the main components of plant cell walls such as cellulose and pectin by compounding pectinase and cellulase, causing the cell wall to partially collapse, dissolve or loosen, thereby accelerating the dissolution rate of effective ingredients; both beta-cyclodextrin and curcumin have a special outer hydrophilic and inner hydrophobic structure, which can encapsulate fat-soluble effective ingredients, increase their solubility, and improve the stability of tea polyphenol components, thereby making the tea rich in tea polyphenols.

[0011] A method for preparing tea leaves rich in tea polyphenols, the method comprising the following steps:

[0012] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0013] Step 2: Cool and microwave the tea leaves after shaking;

[0014] Step 3: Dry the green tea leaves after withering.

[0015] As a preferred technical solution of the present invention, in step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5-6.

[0016] As a preferred technical solution of the present invention, in step 1, the shaking is performed 8-10 times, each time for 4-6 minutes.

[0017] As a preferred technical solution of the present invention, in step one, the rotation speed of the green tea shaking machine is 15-20r / min.

[0018] As a preferred technical solution of the present invention, in step one, the composite infusion comprises the following components by weight: 10-15 parts of pectinase, 15-18 parts of cellulase, 8-10 parts of β-cyclodextrin, 2-3 parts of curcumin, 1-1.2 parts of sodium alginate, 1-2 parts of xylitol, 2-3 parts of emulsion and 60-65 parts of buffer.

[0019] As a preferred technical solution of the present invention, cellulase only destroys the cell walls of tea leaves and has no effect on non-cellulose substances, so it has no effect on tea polyphenols.

[0020] As a preferred technical solution of the present invention, in step one, the emulsion is monoglycerol fatty acid ester.

[0021] As a preferred technical solution of the present invention, in step 2, the cooling is performed at a temperature of 20-30°C and a humidity of 50-80% for 1.5-2.0 hours.

[0022] As a preferred technical solution of the present invention, in step 2, the microwave sterilization time is 40-90s.

[0023] As a preferred technical solution of the present invention, in step three, the drying is performed at 60-70° C. for 1 hour.

[0024] Beneficial effects of the present invention:

[0025] The present invention adds curcumin, which is a polyphenol compound containing multiple hydroxyl groups and benzene ring structures in its structure. It interacts with tea polyphenols through hydrogen bonds, thereby increasing the extraction rate of tea polyphenols. At the same time, curcumin has good antioxidant properties and can effectively inhibit the oxidative degradation of tea polyphenols, thereby protecting the structure and activity of tea polyphenols. Pectinase and cellulase can decompose the main components of plant cell walls such as cellulose and pectin, causing the cell wall to partially collapse, dissolve or loosen, and accelerate the dissolution rate of effective ingredients; both β-cyclodextrin and curcumin have a special external hydrophilic and internal hydrophobic structure, which can encapsulate fat-soluble effective ingredients, increase their solubility, and improve the stability of the effective ingredients. DETAILED DESCRIPTION

[0026] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0027] Example 1

[0028] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0029] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0030] Step 2: Cool and microwave the tea leaves after shaking;

[0031] Step 3: Dry the green tea leaves after withering.

[0032] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.

[0033] In step 1, the shaking is performed 8 times, each time for 4 minutes.

[0034] In step 1, the rotation speed of the tea shaking machine is 15r / min.

[0035] In step 1, the composite infusion comprises the following components by weight: 10 parts of pectinase, 15 parts of cellulase, 8 parts of β-cyclodextrin, 2 parts of curcumin, 1 part of sodium alginate, 1 part of xylitol, 2 parts of emulsion and 60 parts of buffer.

[0036] In step one, the emulsion is monoglyceride of fatty acid.

[0037] In step 2, the cooling is performed at 20° C. and 50% humidity for 1.5 hours.

[0038] In step 2, the microwave sterilization time is 40s.

[0039] In step three, the drying is performed at 60° C. for 1 hour.

[0040] Example 2

[0041] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0042] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0043] Step 2: Cool and microwave the tea leaves after shaking;

[0044] Step 3: Dry the green tea leaves after withering.

[0045] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.2.

[0046] In step 1, the shaking is performed 9 times, each time for 4.5 minutes.

[0047] In step 1, the rotation speed of the tea shaking machine is 16r / min.

[0048] In step 1, the composite infusion comprises the following components by weight: 11 parts of pectinase, 15.8 parts of cellulase, 8.5 parts of β-cyclodextrin, 2.2 parts of curcumin, 1 part of sodium alginate, 1.2 parts of xylitol, 2.2 parts of emulsion and 61 parts of buffer.

[0049] In step one, the emulsion is monoglyceride of fatty acid.

[0050] In step 2, the drying is performed at a temperature of 22° C. and a humidity of 58% for 1.6 hours.

[0051] In step 2, the microwave sterilization time is 52s.

[0052] In step three, the drying is performed at 62° C. for 1 hour.

[0053] Example 3

[0054] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0055] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0056] Step 2: Cool and microwave the tea leaves after shaking;

[0057] Step 3: Dry the green tea leaves after withering.

[0058] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.5.

[0059] In step 1, the shaking is performed 9 times, each time for 5 minutes.

[0060] In step 1, the rotation speed of the tea shaking machine is 18 r / min.

[0061] In step 1, the composite infusion comprises the following components by weight: 12 parts of pectinase, 16.5 parts of cellulase, 9 parts of β-cyclodextrin, 2.5 parts of curcumin, 1.1 parts of sodium alginate, 1.5 parts of xylitol, 2.5 parts of emulsion and 62 parts of buffer.

[0062] In step one, the emulsion is monoglyceride of fatty acid.

[0063] In step 2, the drying is performed at a temperature of 25° C. and a humidity of 65% for 1.8 hours.

[0064] In step 2, the microwave sterilization time is 65s.

[0065] In step three, the drying is performed at 65° C. for 1 hour.

[0066] Example 4

[0067] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0068] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0069] Step 2: Cool and microwave the tea leaves after shaking;

[0070] Step 3: Dry the green tea leaves after withering.

[0071] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.8.

[0072] In step 1, the shaking is performed 9 times, each time for 5.5 minutes.

[0073] In step 1, the rotation speed of the tea shaking machine is 19r / min.

[0074] In step 1, the composite infusion comprises the following components by weight: 14 parts of pectinase, 17 parts of cellulase, 9.5 parts of β-cyclodextrin, 2.8 parts of curcumin, 1.2 parts of sodium alginate, 1.8 parts of xylitol, 2.8 parts of emulsion and 64 parts of buffer.

[0075] In step one, the emulsion is monoglyceride of fatty acid.

[0076] In step 2, the drying is performed at a temperature of 28° C. and a humidity of 72% for 1.9 hours.

[0077] In step 2, the microwave sterilization time is 78s.

[0078] In step three, the drying is performed at 68° C. for 1 hour.

[0079] Example 5

[0080] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0081] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0082] Step 2: Cool and microwave the tea leaves after shaking;

[0083] Step 3: Dry the green tea leaves after withering.

[0084] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:6.

[0085] In step 1, the shaking is performed 10 times, each time for 6 minutes.

[0086] In step 1, the rotation speed of the tea shaking machine is 20r / min.

[0087] In step 1, the composite infusion comprises the following components by weight: 15 parts of pectinase, 18 parts of cellulase, 10 parts of β-cyclodextrin, 3 parts of curcumin, 1.2 parts of sodium alginate, 2 parts of xylitol, 3 parts of emulsion and 65 parts of buffer.

[0088] In step one, the emulsion is monoglyceride of fatty acid.

[0089] In step 2, the drying is performed at a temperature of 30° C. and a humidity of 80% for 2.0 hours.

[0090] In step 2, the microwave sterilization time is 90s.

[0091] In step three, the drying is performed at 70° C. for 1 hour.

[0092] Comparative Example 1

[0093] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0094] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0095] Step 2: Cool and microwave the tea leaves after shaking;

[0096] Step 3: Dry the green tea leaves after withering.

[0097] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.8.

[0098] In step 1, the shaking is performed 9 times, each time for 5.5 minutes.

[0099] In step 1, the rotation speed of the tea shaking machine is 19r / min.

[0100] In step 1, the composite infusion comprises the following components by weight: 31 parts of cellulase, 9.5 parts of β-cyclodextrin, 2.8 parts of curcumin, 1.2 parts of sodium alginate, 1.8 parts of xylitol, 2.8 parts of emulsion and 64 parts of buffer.

[0101] In step one, the emulsion is monoglyceride of fatty acid.

[0102] In step 2, the drying is performed at a temperature of 28° C. and a humidity of 72% for 1.9 hours.

[0103] In step 2, the microwave sterilization time is 78s.

[0104] In step three, the drying is performed at 68° C. for 1 hour.

[0105] Comparative Example 2

[0106] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0107] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0108] Step 2: Cool and microwave the tea leaves after shaking;

[0109] Step 3: Dry the green tea leaves after withering.

[0110] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.8.

[0111] In step 1, the shaking is performed 9 times, each time for 5.5 minutes.

[0112] In step 1, the rotation speed of the tea shaking machine is 19r / min.

[0113] In step 1, the composite infusion comprises the following components by weight: 14 parts of pectinase, 17 parts of cellulase, 12.3 parts of curcumin, 1.2 parts of sodium alginate, 1.8 parts of xylitol, 2.8 parts of emulsion and 64 parts of buffer.

[0114] In step one, the emulsion is monoglyceride of fatty acid.

[0115] In step 2, the drying is performed at a temperature of 28° C. and a humidity of 72% for 1.9 hours.

[0116] In step 2, the microwave sterilization time is 78s.

[0117] In step 3, the drying is performed at 68° C. for 1 hour.

[0118] Comparative Example 3

[0119] A method for preparing tea leaves rich in tea polyphenols comprises the following steps:

[0120] Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them;

[0121] Step 2: Cool and microwave the tea leaves after shaking;

[0122] Step 3: Dry the green tea leaves after withering.

[0123] In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5.8.

[0124] In step 1, the shaking is performed 9 times, each time for 5.5 minutes.

[0125] In step 1, the rotation speed of the tea shaking machine is 19r / min.

[0126] In step 1, the composite infusion comprises the following components by weight: 14 parts of pectinase, 17 parts of cellulase, 12.3 parts of β-cyclodextrin, 1.2 parts of sodium alginate, 1.8 parts of xylitol, 2.8 parts of emulsion and 64 parts of buffer.

[0127] In step one, the emulsion is monoglyceride of fatty acid.

[0128] In step 2, the drying is performed at a temperature of 28° C. and a humidity of 72% for 1.9 hours.

[0129] In step 2, the microwave sterilization time is 78s.

[0130] In step three, the drying is performed at 68° C. for 1 hour.

[0131] The tea leaves prepared in Examples 1-5 and Comparative Examples 1-3 were tested for tea polyphenol content, and the test results are shown in Table 1.

[0132] Table 1

[0133]

[0134]

[0135] From the test results in Table 1, it can be seen that compared with Comparative Examples 1-3, the tea polyphenols content of the tea leaves prepared in Examples 1-5 of the present invention is significantly better than that in Comparative Examples 1-3.

[0136] The present invention adds curcumin, which is a polyphenol compound containing multiple hydroxyl groups and benzene ring structures in its structure. It interacts with tea polyphenols through hydrogen bonds, thereby increasing the extraction rate of tea polyphenols. At the same time, curcumin has good antioxidant properties and can effectively inhibit the oxidative degradation of tea polyphenols, thereby protecting the structure and activity of tea polyphenols. Pectinase and cellulase can decompose the main components of plant cell walls such as cellulose and pectin, causing the cell wall to partially collapse, dissolve or loosen, and accelerate the dissolution rate of effective ingredients; both β-cyclodextrin and curcumin have a special external hydrophilic and internal hydrophobic structure, which can encapsulate fat-soluble effective ingredients, increase their solubility, and improve the stability of the effective ingredients.

[0137] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing tea leaves rich in tea polyphenols, characterized in that: The tea preparation method comprises the following steps: Step 1: Mix the green tea leaves and the compound infusion evenly and then shake them; Step 2: Cool and microwave the tea leaves after shaking; Step 3: Dry the green tea leaves after withering.

2. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 1, the mass ratio of the green tea leaves to the composite infusion is 24:5-6.

3. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 1, the shaking is performed 8-10 times, each time for 4-6 minutes.

4. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 1, the rotation speed of the tea-shaking machine is 15-20 r / min.

5. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 1, the composite infusion comprises the following components by weight: 10-15 parts of pectinase, 15-18 parts of cellulase, 8-10 parts of β-cyclodextrin, 2-3 parts of curcumin, 1-1.2 parts of sodium alginate, 1-2 parts of xylitol, 2-3 parts of emulsion and 60-65 parts of buffer.

6. The method for preparing tea leaves rich in tea polyphenols according to claim 5, characterized in that: In step one, the emulsion is monoglyceride of fatty acid.

7. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 2, the cooling is performed at a temperature of 20-30° C. and a humidity of 50-80% for 1.5-2.0 hours.

8. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step 2, the microwave sterilization time is 40-90s.

9. The method for preparing tea leaves rich in tea polyphenols according to claim 1, characterized in that: In step three, the drying is performed at 60-70° C. for 1 hour.

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