Method for increasing theaflavin content in tea leaves
By using the residual heat of the pan-fried tea leaves for secondary fermentation and packaging, the complexity and high cost of increasing theaflavin content have been solved, resulting in a significant increase in theaflavin content and the maintenance of tea quality.
Patent Information
- Application Number
- CN202511408816.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2025-12-12
AI Technical Summary
Existing technologies for increasing the theaflavins content in tea are complex, costly, and may affect other aspects of tea quality, making it difficult to achieve efficient and low-cost improvements.
After pan-frying, the tea leaves undergo secondary fermentation using residual heat. Food-grade plastic bags and burlap bags are used for packaging to control fermentation conditions and promote the synthesis of theaflavins. This process includes pan-frying, sealing, and drying.
It significantly increases the theaflavin content by 37.5%-38.5%, is simple to operate, low in cost, maintains the other qualities of tea without damage, and improves the overall quality.
Abstract
Description
Technical Field
[0001] This invention relates to the field of tea processing technology, and more specifically to a method for increasing the theaflavins content in tea. Background Technology
[0002] Theaflavins, also known as thearubigins, are important polyphenol oxidation products in tea, primarily found in fully fermented black tea. They are key components that give black tea its bright golden color and unique flavor. Other types of tea (such as oolong tea and dark tea) may also contain small amounts of theaflavins, but at significantly lower levels than black tea. Biochemically, theaflavins are substances with phenolic hydroxyl groups forming benzophenone structures, and were the first compounds found in tea with definite pharmacological effects. Theaflavins account for 0.5% to 2% of the dry weight of tea, depending on the processing method. Theaflavins play a role in the bright color and strong flavor of tea, and are also important components for the intensity and freshness of the tea's taste. They also possess various health benefits such as antioxidant, anti-inflammatory, and lipid-lowering effects. However, the total amount of theaflavins in black tea is generally between 1.3% and 1.8%, which is relatively low. Therefore, increasing the theaflavin content in tea is of great significance for improving tea quality and nutritional value.
[0003] Currently, methods for increasing theaflavins content in tea processing mainly focus on optimizing fermentation parameters, such as precise control of temperature, humidity, and time. However, these methods often require complex equipment and strict process monitoring, resulting in high costs and operational difficulties. Furthermore, some methods may adversely affect other quality components of tea during fermentation, leading to a decline in the overall quality of the tea.
[0004] Therefore, how to develop a simple, efficient, low-cost method to increase the theaflavins content of tea while maintaining other qualities of tea is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a method for increasing the theaflavins content in tea, so as to overcome the shortcomings of the prior art.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A method for increasing the theaflavins content in tea leaves specifically includes the following steps:
[0008] (1) Select tea leaves that are plump, tender green, and free from pests, diseases and mechanical damage for later use;
[0009] (2) The tea leaves are stir-fried using the pan-frying process;
[0010] (3) Quickly remove the stir-fried tea leaves from the pan, immediately put them into a food-grade plastic bag and seal it quickly, then put them into a burlap bag.
[0011] (4) Use the residual heat of the tea leaves after frying to allow the tea leaves to undergo secondary fermentation in a burlap bag;
[0012] (5) After the second fermentation is completed, the tea leaves are taken out, dried, sieved and packaged to obtain the finished tea.
[0013] Furthermore, in step (2) above, the frying temperature is 180-220℃ and the time is 3-8 minutes.
[0014] The further beneficial effects of the above-mentioned method are that by selecting fresh tea leaves and using conventional pan-frying techniques, the tea leaves achieve the appropriate degree of fixation, stopping enzyme activity, fixing the quality of the tea, and simultaneously dissipating some of the grassy aroma, creating favorable conditions for subsequent fermentation. The pan-frying temperature is controlled between 180-220℃, and the frying time is adjusted according to the variety and freshness of the tea leaves, generally 3-8 minutes. The ideal state is when the tea leaves soften, can be formed into a ball by hand, crumbles easily when released, has a slight elasticity, and the aroma of tea is evident.
[0015] Furthermore, in step (3) above, the material of the food-grade plastic bag is polyethylene (PE) or polypropylene (PP), etc.
[0016] The further beneficial effect of the above-mentioned method is that the food-grade plastic bag selected in this invention has good sealing properties and a certain degree of flexibility, which can withstand the gas pressure generated by the tea during the secondary fermentation process, while not releasing harmful substances that would contaminate the tea.
[0017] Furthermore, in step (3) above, the food-grade plastic bag is 50-100cm long, 30-60cm wide, and 0.05-0.2mm thick, with a sealing device at the opening. Even further, the sealing device is a zipper closure or a heat-sealing strip.
[0018] A further beneficial effect of adopting the above-mentioned method is that the size of the food-grade plastic bags is designed according to the processing volume of tea and packaging requirements. The opening of the food-grade plastic bags is equipped with sealing devices such as zipper closures or heat-sealing strips to ensure good sealing performance.
[0019] Furthermore, in step (3) above, the linen bag is woven from natural linen fibers.
[0020] The further beneficial effect of the above-mentioned method is that the burlap bag selected in this invention has good air permeability and heat preservation, which can regulate the temperature and humidity environment during the secondary fermentation process of tea to a certain extent, and at the same time provide a relatively stable fermentation space for tea.
[0021] Furthermore, in step (3) above, the burlap bag is 60-110cm long and 40-70mm wide, and has a sealing device at the opening. Even further, the sealing device is a drawstring or a snap fastener.
[0022] A further beneficial effect of the above-mentioned approach is that the size of the burlap bag should be slightly larger than that of the food-grade plastic bag so that it can be easily filled with the plastic bag. The opening of the burlap bag is equipped with a drawstring or snap closure device for easy sealing after tea leaves are filled.
[0023] Furthermore, in step (4) above, the secondary fermentation time is 25-35 minutes.
[0024] The further beneficial effect of the above-mentioned method is that, during the secondary fermentation process, the microorganisms and enzymes inside the tea leaves continue to work under suitable temperature and humidity conditions, promoting the synthesis and transformation of components such as theaflavins.
[0025] Furthermore, in step (5) above, the drying temperature is 80-90℃ and the time is 1-2h.
[0026] The further beneficial effect of the above method is that, through drying, the moisture content of the tea leaves is reduced to 5%-6%.
[0027] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:
[0028] 1. Increase the content of theaflavins
[0029] This invention utilizes the residual heat of the tea leaves after roasting to conduct a secondary fermentation under specific packaging conditions. This provides suitable conditions for the activity of microorganisms and enzymes within the tea leaves, effectively promoting the synthesis and conversion of theaflavins and significantly increasing the theaflavin content in the tea. Experimental verification shows that tea processed using this method has a 37.5%-38.5% higher theaflavin content than tea processed using traditional methods.
[0030] 2. Simple and convenient to operate
[0031] The method of this invention does not require complex equipment investment or strict process monitoring. It only requires adding a simple packaging step and a short secondary fermentation time to the conventional pan-frying process to increase the theaflavins content. It is simple to operate and suitable for large-scale tea processing and production.
[0032] 3. Low cost
[0033] The food-grade plastic bags and burlap bags used in this invention are low-cost and reusable, reducing tea processing costs. Furthermore, since no additional energy consumption is required to maintain the fermentation temperature, production costs are further reduced.
[0034] 4. Maintain other qualities of the tea
[0035] The secondary fermentation process of this invention is carried out under relatively mild conditions, which will not adversely affect other quality components of tea such as tea polyphenols, amino acids, and aroma substances. It can maintain the quality characteristics of tea such as color, aroma, and taste, and improve the overall quality of tea.
[0036] In summary, the method of the present invention can effectively increase the theaflavins content in tea, and is simple and convenient to operate, low in cost, while maintaining other qualities of tea, thereby improving the overall quality of tea. Detailed Implementation
[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0038] Example 1
[0039] The methods to increase the theaflavins content in tea include the following steps:
[0040] (1) Selection of tea leaves
[0041] Select 10kg of fresh Fuding Da Bai tea leaves. The tea leaves should have plump buds and leaves, tender green color, and be free from diseases, pests, and mechanical damage.
[0042] (2) Stir-frying process
[0043] Place the tea leaves into the frying machine, set the frying temperature to 200℃, and the frying time to 5 minutes. During the frying process, stir the tea leaves continuously to ensure that they are heated evenly. After frying, the tea leaves become soft, can be squeezed into a ball by hand, and crumble when released. They are slightly elastic and have a distinct tea aroma.
[0044] (3) Remove from the pot and pack into bags
[0045] Quickly remove the stir-fried tea leaves from the pan and pack them into a food-grade polyethylene plastic bag measuring 80cm in length, 50cm in width, and 0.1mm in thickness. Seal the plastic bag with a zipper closure.
[0046] (4) Secondary packaging
[0047] Place the food-grade polyethylene plastic bag containing tea into a linen bag woven from natural hemp fibers, measuring 90cm in length and 60cm in width. Tighten the drawstring at the opening of the linen bag to seal it.
[0048] (5) Secondary fermentation with residual heat
[0049] Place the burlap bag containing tea leaves in a well-ventilated indoor environment with a suitable temperature (20-25℃) to allow for secondary fermentation using the residual heat of the tea leaves. The fermentation time is 30 minutes.
[0050] (6) Follow-up processing
[0051] After the secondary fermentation is completed, the burlap bag and food-grade polyethylene plastic bag are opened, the tea leaves are taken out and put into a dryer for drying. The drying temperature is controlled at 80℃ and the drying time is 2 hours, so that the moisture content of the tea leaves is reduced to 5%-6%. Then the dried tea leaves are sieved to remove impurities and fragments, and finally packaged to obtain the finished tea.
[0052] Testing revealed that the theaflavins content of tea processed using the method described in this embodiment was 1.8%, while the theaflavins content of the same batch of tea processed using traditional methods was 1.3%, representing an increase of 38.5%. Simultaneously, the tea exhibited a vibrant green color, a long-lasting aroma, and a fresh, invigorating taste, resulting in a significant improvement in overall quality.
[0053] Example 2
[0054] The methods to increase the theaflavins content in tea include the following steps:
[0055] (1) Selection of tea leaves
[0056] Select 8kg of fresh Zhenghe Da Bai tea leaves. The tea leaves should have plump buds and leaves, tender green color, and be free from pests, diseases, and mechanical damage.
[0057] (2) Stir-frying process
[0058] Place the tea leaves into the frying machine, set the frying temperature to 190℃, and the frying time to 4 minutes. During the frying process, stir the tea leaves continuously to ensure that they are heated evenly. After frying, the tea leaves become soft, can be squeezed into a ball by hand, and will crumble when released. They are slightly elastic and have a distinct tea aroma.
[0059] (3) Remove from the pot and pack into bags
[0060] Quickly remove the stir-fried tea leaves from the pan and pack them into a food-grade polypropylene plastic bag measuring 70cm in length, 45cm in width, and 0.08mm in thickness. Seal the plastic bag with a heat seal strip.
[0061] (4) Secondary packaging
[0062] Place the food-grade polyethylene plastic bag containing tea into a linen bag woven from natural hemp fibers, measuring 80cm in length and 55cm in width. Fasten the buckle at the opening of the linen bag to seal it.
[0063] (5) Secondary fermentation with residual heat
[0064] Place the burlap bag containing tea leaves in a well-ventilated indoor environment with a suitable temperature (20-25℃) to carry out secondary fermentation using the residual heat of the tea leaves. The fermentation time is 30 minutes.
[0065] (6) Follow-up processing
[0066] After the secondary fermentation is completed, the burlap bag and food-grade polyethylene plastic bag are opened, the tea leaves are taken out and put into a dryer for drying. The drying temperature is controlled at 85℃ and the drying time is 1.5 hours, so that the moisture content of the tea leaves is reduced to 5%-6%. Then the dried tea leaves are sieved to remove impurities and fragments, and finally packaged to obtain the finished tea.
[0067] Testing revealed that the tea processed using the method described in this embodiment contained 1.65% theaflavins, while the same batch of tea processed using traditional methods contained only 1.2% theaflavins, representing an increase of 37.5%. Furthermore, the tea exhibited a vibrant green color, a long-lasting aroma, and a fresh, invigorating taste, resulting in a significant improvement in overall quality.
[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for increasing the theaflavins content in tea, characterized in that, Specifically, the following steps are included: (1) Select tea leaves that are plump, tender green, and free from pests, diseases and mechanical damage for later use; (2) The tea leaves are stir-fried using the pan-frying process; (3) Quickly remove the stir-fried tea leaves from the pan, immediately put them into a food-grade plastic bag and seal it quickly, then put them into a burlap bag. (4) Use the residual heat of the tea leaves after frying to allow the tea leaves to undergo secondary fermentation in a burlap bag; (5) After the second fermentation is completed, the tea leaves are taken out, dried, sieved and packaged to obtain the finished tea.
2. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (2), the frying temperature is 180-220℃ and the time is 3-8 minutes.
3. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (3), the food-grade plastic bag is made of polyethylene or polypropylene.
4. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (3), the food-grade plastic bag is 50-100cm long, 30-60cm wide, and 0.05-0.2mm thick, and has a sealing device at the opening.
5. The method for increasing the theaflavins content in tea according to claim 4, characterized in that, The sealing device is a zipper seal or a heat seal.
6. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (3), the linen bag is woven from natural linen fibers.
7. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (3), the burlap bag is 60-110cm long and 40-70mm wide, and has a sealing device at the opening.
8. A method for increasing the theaflavins content in tea according to claim 7, characterized in that, The sealing device is a drawstring or a buckle.
9. The method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (4), the secondary fermentation time is 25-35 minutes.
10. A method for increasing the theaflavins content in tea according to claim 1, characterized in that, In step (5), the drying temperature is 80-90℃ and the time is 1-2h.