Method for promoting aged tea flavor of tea leaves by using saturated salt solution

Abstract

The invention discloses a method for promoting the flavor of aged tea leaves by using a saturated salt solution, which comprises the following steps: placing a food-grade saturated salt solution in a sealable cavity environment, enabling the temperature and water activity of the cavity environment to meet preset requirements, placing tea leaves to be treated with preset water content in the cavity environment, then closing the cavity environment, and placing the tea leaves to be treated in the cavity environment. In cooperation with constant-temperature and constant-humidity equipment, the tea leaves to be treated are allowed to stand for a preset period of time under the conditions of constant temperature, humidity control and light shielding, so that the tea leaves are aged, and an aged tea flavor is formed; the scheme has the advantages that the processing time is short, batch processing can be realized, and the aged-flavor tea leaves can be directionally produced, the tea leaves can statically absorb water (water generated by saturated salt volatilization) in a cavity environment within a short time of 30-60 days through the processing of the scheme, and the aged-tea-flavor tea leaves can be reprocessed on a large scale.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, and in particular to a method for enhancing the flavor of aged tea using a saturated salt solution. Background Technology

[0002] Aged tea is favored by some consumers for its unique flavor. The aging of tea is a complex and interesting process, like a subtle dialogue between the internal substances of tea and time. Simply put, tea aging refers to the phenomenon in which the flavor substances contained in tea undergo a series of chemical reactions such as oxidation, polymerization, and hydrolysis under the influence of environmental conditions such as oxygen, temperature, and humidity during the storage process, resulting in changes in the color, aroma, and taste of the tea.

[0003] The commonly used tea aging techniques currently include the following:

[0004] 1. Humidification and Heating Artificial Aging Technology: This method mainly involves spraying water to humidify raw tea (black tea, white tea, red tea, oolong tea) (water accounts for 10% to 20% of the tea weight), heating and piling it (35℃ to 45℃) for a period of time (7 to 30 days), so that the tea undergoes a post-fermentation process similar to the "piling" of black tea. Then it is dried to a moisture content of 5% to 8% to form the finished tea. The processed finished tea has the unique aged aroma and flavor of aged tea (aged tea, old tea, vintage tea).

[0005] The process can be briefly summarized as follows: finished tea → humidification (moistening) → heating and stacking → drying → aging tea.

[0006] 2. Black Tea Pile Fermentation Technique: This method requires a humid and hot environment. The temperature at the center of the pile must be precisely controlled within the range of 50℃ to 65℃. Temperature is adjusted and kept uniform by turning the pile. The initial moisture content of the raw tea leaves (crude tea) should be approximately 60%. Water is added as needed during turning to maintain a high humidity environment (relative humidity > 85%). A moderately anaerobic state must be maintained inside the pile to facilitate fermentation dominated by anaerobic / facultative anaerobic microorganisms. However, complete anoxic conditions are detrimental; brief aeration through turning is necessary to replenish oxygen, dissipate waste gases, and promote balanced reaction. Fermentation time is significantly affected by the raw materials, temperature, and humidity, ranging from a few hours to several weeks (approximately 40-60 days for ripe Pu-erh tea). The fermentation process is based on the degree of fermentation (browning of leaves, loss of grassy aroma, and the appearance of mellow fragrance), rather than a fixed time; it requires "tea-based processing."

[0007] The process can be summarized as follows: fresh leaves → fixation → rolling → piling → drying → finished tea.

[0008] 3. Natural Aging Technology for Tea: This method requires a controlled environment with moderate ventilation, a temperature of 20℃-25℃, relative humidity of 60%-75%, and protection from light. It utilizes time to slowly oxidize and synergize with microorganisms in finished tea products (such as raw Pu-erh tea, aged white tea, Liubao tea, and traditional oolong tea), achieving flavor and quality enhancement. The ideal range is within this range; excessively high humidity (>80%) easily leads to mold growth, while excessively low humidity (<50%) halts oxidation. Aging requires several years or even decades. The optimal drinking period varies for different tea types (e.g., raw Pu-erh tea approximately 10-30 years, white tea 3-15 years). Non-sealed packaging provides the oxygen needed for oxidation, but excessive exposure must be avoided to prevent aroma loss.

[0009] Among these methods, artificial aging techniques involving humidification and heating require materials to be piled up under long-term high temperature and high humidity conditions, which can easily produce off-flavors and odors. The final drying process can cause the aroma compounds in the tea to volatilize. Although this creates an aged flavor, the overall quality of the tea decreases, and microorganisms can easily grow during the piling process. In order to preserve the tea's original aroma, the drying temperature is controlled at a low level, resulting in insufficient sterilization of microorganisms and potential residual activity, posing a quality and safety hazard. The piling technique for dark tea is limited to the initial processing of dark tea and is suitable for processing from fresh leaves to finished tea. It is not suitable for the further processing of finished tea or for reprocessing finished tea into aged tea flavor products. Natural aging techniques for tea, on the other hand, are time-consuming, generally requiring 3 to 15 years to develop the flavors of aged teas from different years. During long-term natural storage, it requires handling warehouse pressure, and natural aging is greatly affected by the storage environment, often resulting in unstable and uneven quality. This makes it impossible to mass-produce or scale up production, and it cannot be converted into economic benefits in a timely manner.

[0010] Therefore, how to propose a reliable and stable aging process that can promote the formation of flavor in aged tea while ensuring its quality is a topic of great practical significance. Summary of the Invention

[0011] In view of this, the purpose of this invention is to provide a method for promoting the flavor of aged tea using a saturated salt solution that has a stable aging effect, is convenient and easy to operate.

[0012] To achieve the above-mentioned technical objectives, the technical solution adopted by this invention is as follows:

[0013] A method for promoting the aged flavor of tea using a saturated salt solution includes: placing a food-grade saturated salt solution in a sealable cavity environment, ensuring that the temperature and moisture activity of the cavity environment meet preset requirements, then placing tea leaves with a preset moisture content into the cavity environment, and then sealing it, allowing the tea leaves to be treated to stand for a preset time under constant temperature, humidity, and light-proof conditions, so that the tea leaves can age and develop an aged flavor.

[0014] As a possible alternative implementation, the food-grade saturated salt solution described in this solution is prepared from food-grade sodium nitrate or sodium chloride.

[0015] In this method, a saturated solution of food-grade sodium nitrate or sodium chloride is used to regulate the water activity in a sealed cavity, creating stable humidity conditions, while the oxygen level in the sealed cavity maintains a moderate oxidation reaction. This method places dried tea leaves in a temperature-controlled and humidity-controlled sealed cavity. Humidity control within the sealed cavity assists in the aging of the tea leaves. By placing a saturated salt solution, varying humidity environments are created through the evaporation of water from the saturated salt solution. This allows the tea leaves to absorb the gradually released environmental moisture, causing the compounds in the tea leaves to undergo non-enzymatic oxidation, promoting the formation of aged flavor and significantly increasing the content of aged aroma substances, thus creating a more harmonious aged flavor in terms of sensory perception.

[0016] As a preferred implementation method, this solution places the food-grade saturated salt solution in a sealable cavity environment, maintaining the temperature of the cavity environment at 25±2℃ and the water activity at 0.740~0.760.

[0017] As a preferred embodiment, the moisture content of the tea leaves to be treated in this scheme is preferably 3% to 5%. When the moisture content of the tea leaves to be treated is higher than this range, as a preferred embodiment, the tea leaves to be treated in this scheme are further pretreated, which includes drying the tea leaves to be treated at a temperature of 40 to 50°C until the moisture content is 3% to 5%.

[0018] As a possible alternative implementation, the tea leaves to be processed in this solution are further placed in a food-grade breathable bag when placed in the cavity environment.

[0019] As a preferred implementation method, the settling time described in this solution is preferably 10 to 90 days; as a preferred example, the settling time described in this solution is 30 to 90 days. During the settling process, the cavity environment is opened for ventilation for 30 minutes every 10 days, and then it is resealed and the constant temperature, humidity control and light protection conditions are maintained.

[0020] As a preferred implementation method, after the tea leaves have been aged, the moisture content is tested. If the moisture content exceeds the preset value, the tea leaves are dried at a temperature of 40-70°C until the moisture content is lower than the preset value.

[0021] As an example, before the tea leaves to be treated are placed in the cavity environment, when preparing 1000 mL of saturated sodium nitrate solution, first measure about 532 g of water, then gradually add 468 g of sodium nitrate while stirring until the solid no longer dissolves, and finally bring the volume to 1000 mL to prepare 1000 mL of saturated sodium nitrate solution. When using a desiccator as the cavity environment, the saturated sodium nitrate solution is placed in a standard desiccator to maintain a stable closed environment, then the desiccator is sealed with Vaseline, and then the desiccator is placed in a constant temperature and humidity chamber (25°C, 65% RH) for equilibration for 7 days to form a closed cavity environment with a consistent water activity (aw = 0.743). When sodium chloride is used as the saturated salt solution, a similar effect can be achieved with the saturated sodium chloride water activity aw = 0.755.

[0022] Based on the above, the finished tea leaves are placed in an oven and dried at 40-50℃ for 3-6 hours, until the moisture content reaches a monolayer state of 3%-5%. Then, 500g of the finished tea is placed in a food-grade breathable gauze bag and placed in a desiccator that has undergone the above balancing treatment, maintaining constant temperature and humidity conditions, and then left to stand in the dark for 30-90 days. During this standing period, the lid is opened for 30 minutes every 10 days. During this process, the tea leaves begin to reabsorb the free water molecules volatilized from the saturated salt solution, and slowly and gradually transform into semi-free water and bound water within the tea leaves. During this time, the water molecules act as a solvent, participating in the oxidation of flavor compounds within the tea leaves. After 30 days, the tea begins to develop a distinct aged tea flavor, which becomes more pronounced with longer storage.

[0023] In this method, the duration of tea reabsorption can be controlled according to flavor requirements. Finally, the reabsorbed tea is taken out and its moisture content is tested. Generally, the moisture content of the reabsorbed tea is 6%-9% or lower. Operators can then dry the tea at 40-70℃ for 3-6 hours, depending on the type of tea, until the moisture content reaches approximately 5%. For black tea, white tea, etc., the moisture content can be controlled to meet the corresponding product standards. If it directly meets the standards, drying is not necessary.

[0024] This solution allows raw tea to be directly reprocessed into tea with the flavor of aged tea. The entire production process can be mass-produced and can promote the development of the flavor of naturally aged tea (1-15 years) within 10-90 days.

[0025] This scheme uses raw tea as the raw material for the reprocessing of aged tea flavor, but it does not spray water on the raw tea or actively add moisture to the raw tea. Therefore, it can avoid or reduce the degree of intervention of secondary drying, thereby reducing the loss of tea aroma components caused by low-temperature drying.

[0026] Based on the above, this solution also proposes a aged tea flavored tea, which is prepared by the method described above, and the tea is white tea, oolong tea, black tea, dark tea, green tea, yellow tea, jasmine tea, etc.

[0027] Compared with existing technologies, the present invention, employing the above-described technical solution, has the following advantages: This solution offers advantages such as short processing time, batch processing capability, and targeted production of aged tea flavors. Through this solution, tea leaves can statically absorb water (water produced by the volatilization of saturated salts) within a cavity environment within a short period of 30-60 days, enabling large-scale reprocessing to produce aged tea flavors. Depending on the number of days of static water absorption, this solution can adjust the aging time by optimizing the processing time, thereby targeted processing to produce aged tea flavors similar to those naturally aged for 1-3 years, 4-7 years, 8-12 years, and over 15 years. Because the aging process is conducted in a sealed environment with controlled humidity, temperature, and oxygen, the transformation of tea flavor proceeds in a consistent aging direction. Simultaneously, it avoids the impact of environmental odors, off-flavors, and microbial metabolism on tea quality. Therefore, the quality of the aged tea products processed using this solution is significantly superior to existing technologies such as "artificial aging with heating and humidification," and the samples exhibit better uniformity and consistency. In addition, the entire reprocessing of aged tea flavor in this scheme uses raw tea as raw material, but does not spray water on the raw tea or add extra moisture to the raw tea. Therefore, it can avoid or reduce the degree of secondary drying, thereby reducing the loss of tea aroma components caused by low-temperature drying. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a radar chart showing the tea tasting characteristics at different processing times according to the method described in this scheme;

[0030] Figure 2 This is a hierarchical clustering heatmap of volatile components in tea leaves at different treatment times using the method described in this scheme;

[0031] Figure 3 This diagram illustrates the changes in the content of key substances in tea leaves treated with this method at different treatment times.

[0032] Figure 4 This is a diagram showing the ACI values ​​of key substances in tea leaves after treatment using the method described in this scheme. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This embodiment takes black tea as an example and proposes a method for enhancing the aged flavor of tea using a saturated salt solution, which includes the following:

[0035] Prepare 1000 mL of food-grade saturated sodium nitrate solution and place it in an open reagent bottle. Then place the bottle in a standard desiccator with a diameter of 24 cm (the inside of the desiccator is used as a cavity environment) to maintain a stable closed environment. Simultaneously set up three parallel samples and seal the desiccator with Vaseline. Then place them in a constant temperature and humidity chamber (25℃, 65%RH) for two days to equilibrate and allow them to form a closed environment with a consistent water activity (aw=0.743).

[0036] 500g of Jin Mudan black tea, pre-dried to a moisture content of 4.5%, was placed into food-grade breathable gauze bags and then placed in the desiccator that had undergone the above treatment. The tea leaves (Jin Mudan black tea) were kept at a constant temperature of 25℃, under controlled humidity and light conditions. The black tea leaves and the saturated sodium nitrate solution did not come into direct contact, and the lid was opened for ventilation for 30 minutes every 10 days.

[0037] In this scheme, samples are taken and tested every 10 days, specifically at 10, 20, 30, 40, 50, and 60 days. Three parallel experiments are used to achieve three replicates. The final 60-day processed tea, after testing, has a moisture content of 5.5%–6.5%, which meets the national standard GB / T13738.2-2017 "Black Tea Part 2: Congou Black Tea" requirement of ≤7.0%. Therefore, drying is not required.

[0038] Review and quantitative descriptive analysis

[0039] Samples taken at 10, 20, 30, 40, 50, and 60 days were tasted and evaluated by nine professional tasters (five women and four men) from the Tea Industry Innovation Laboratory of Fujian Agriculture and Forestry University, according to GB / T23776—2018 "Sensory Evaluation Methods for Tea". Aroma quality was evaluated using comments. After discussion, five aroma attributes (floral, sweet, aged, grassy, ​​and persistent) and six taste attributes (astringent, sour, aged, rough, grassy, ​​and strong) were quantitatively described and analyzed. A five-point intensity scale was then used for scoring, with an intensity scale of 0–5 (0 for undetectable, 1 for weak, 2 for weak, 3 for strong, 4 for strong, and 5 for very strong). Each sample was randomly evaluated three times, and the average score was taken as the final score. The results are shown below. Figure 1 As shown.

[0040] from Figure 1 The results analysis shows the impact of the closed-loop humidity control treatment on the sensory quality of black tea. The 30-day treatment group exhibited a mellow aroma, reaching the sensory perception threshold for the first time. Under closed-loop humidity control, prolonged storage promotes the aging of tea flavor, accompanied by secondary changes such as increased astringency and decreased body. Therefore, the simultaneous appearance of mellow aroma and mellow flavor reveals a series of chemical reactions occurring during storage, which are perceived by taste receptors to form the mellow flavor characteristic. Dynamic changes in other flavor factors (such as increased astringency and greenness) disrupt the original flavor balance, further highlighting the sensory significance of mellow flavor through a contrast effect. Together with the mellow aroma, they construct the characteristic flavor system of tea in the later stages of storage.

[0041] from Figure 1 It can also be seen that as the processing time is extended (10 to 60 days), the sensory characteristics of black tea show a trend of gradually transforming from floral and fruity aroma to aged aroma.

[0042] In terms of aroma, samples aged 10-20 days were still dominated by floral and sweet aromas, with no apparent aged aroma. By 30 days, the aged aroma began to reach a sensory threshold, while the floral and sweet aromas significantly diminished. Extending the time further to 40-60 days, the intensity of the aged aroma continued to increase and became the dominant aroma attribute, while the floral and sweet aromas weakened considerably. Overall, the radar chart results revealed a "floral-aged aroma" progression in the aroma characteristics of black tea during artificial aging, consistent with the dynamic mechanism of the volatilization and decay of floral and fruity aromas and the accumulation of aged aroma substances during tea storage.

[0043] Figure 1 Aroma radar map ( Figure 1 A) and flavor radar chart ( Figure 1B) Combining these findings, it can be seen that the changes in the flavor dimension are highly consistent with the aroma results. Samples aged 10–20 days exhibited a predominantly mellow and sweet flavor, lacking aged characteristics; by 30 days, aged characteristics began to appear, accompanied by a slight increase in astringency and a decrease in richness. Further extending to 40–60 days, the aged characteristics gradually intensified, closely matching the temporal progression of aroma aging.

[0044] Volatile component determination

[0045] For the determination of volatile components, the following method is used in this scheme:

[0046] (1) Extraction of volatile components: Weigh 0.5g of tea powder into a 20mL headspace vial, add 3mL of water and 20μL of ethyl decanoate (internal standard) and mix thoroughly. After equilibration at 60℃ for 15min, push out the extraction head and adsorb it 1cm above the tea sample for 40min, desorb it for 5min, and then extract the next sample. Each sample was tested 3 times.

[0047] (2) Gas chromatography conditions: The carrier gas was helium with a purity of ≥99.99%, the linear flow rate was 48.40 cm·s⁻¹, the injection port temperature was set to 250℃, and the splitless mode was used. The initial GC temperature was 35℃ for 2 min, then the temperature was increased to 210℃ at 5℃ / min and held for 3 min, and then increased to 250℃ at 10℃ / min and held for 1 min.

[0048] (3) Mass spectrometry conditions: ionization energy 70 eV, ion source temperature 230℃, transfer line temperature 230℃, mass (m / z) scan range 35~350, solvent delay time 4 min.

[0049] Qualitative and quantitative analysis of volatile compounds and ROAV calculation:

[0050] Qualitative analysis: Based on the mass spectrometry information of each chromatographic peak in the total ion chromatogram, a tandem search was performed using the NIST20.0 standard mass spectrometry library. The results were combined with retention time (RT), retention index (RI), RI range deviation ±50, mass spectrometry matching degree ≥80%, and relevant literature for further qualitative analysis.

[0051] Quantitative analysis: Quantification was performed using the internal standard method. 20 μL of ethyl decanoate solution (10 mg·L⁻¹) was added to 3 mL of tea infusion. -1 The compound was used as an internal standard, followed by SPME extraction. The relative content of each compound was calculated by comparing its peak area with that of the internal standard, using the following formula:

[0052]

[0053] Where: M i M represents the peak area of ​​the volatile components. is The area of ​​the internal standard peak; mis m is the mass of the added ethyl caprate internal standard; V is the volume of the sample.

[0054] Relative odor activity value (ROAV) is a quantitative measurement method, calculated by the ratio of the concentration of a volatile compound to its odor threshold in the corresponding medium. Generally, compounds with ROAV > 1 are considered to play an important role in the overall aroma of the analyzed sample, and 0.5 < ROAV < 1 indicates that the volatile compound has a potential contribution to the overall aroma but has not reached a dominant role. According to previous studies, the calculation formula of ROAV is as follows:

[0055]

[0056] Where C i represents the relative content of the i-th volatile compound (unit: μg·kg -1 ); C stan is the relative content of the aroma compound with the highest relative content in the sample (unit: μg·kg -1 ); T stan is the odor threshold of the characteristic benchmark compound in water (unit: μg·kg -1 ); T i is the odor threshold of this compound in water (unit: μg·kg -1 ).

[0057] Figures 2 to 4 shows the effect of airtight humidity control treatment on the volatile components of black tea.

[0058] It can be known that as the storage time prolongs, the content of aroma components shows dynamic changes. Some aroma components such as linalool (citrus flower sweet rose aroma), methyl salicylate (mint aroma), etc. show a negative regulation trend, while 2,2,6-trimethylcyclohexanone (earthy aroma), dihydroactinidiolide (coumarin aroma), etc. show significant positive regulation characteristics.

[0059] Based on the VIP value screening of the OPLS-DA model (VIP > 1), a total of 52 key aroma compounds that contribute significantly to the sample discrimination were identified and a heat map was drawn. Figure 2 shows the hierarchical clustering heat map of volatile components at different treatment times. Among them, Figure 2 the 10-1 on the abscissa represents the 1st group in the three parallel experimental groups after 10 days of aging treatment, and the others are类推 in the same way and will not be elaborated here.

[0060] Overall, the levels of most floral and fresh-scented compounds (such as linalool, nerol, and α-ionone) were high at 10–20 days, then gradually decreased, especially weakening significantly at 50–60 days. This is consistent with the trend of gradually diminishing floral and fruity aromas observed in sensory evaluations.

[0061] In contrast, some compounds associated with aged aroma and woody notes (such as 2,2,6-trimethylcyclohexanone, trans-2-nonenal, β-ionone, and dihydrolinalool) gradually accumulate during the later stages of storage, reaching their peak at 40–60 days. This enhancement of the aroma is highly consistent with the significant improvement in "aged aroma" observed in sensory evaluations.

[0062] Furthermore, esters (such as hexanoate and leaf hexanoate) are at higher levels in the early stages of storage, providing black tea with a distinct fruity aroma and freshness, but their levels decrease significantly in the later stages. This trend indicates that esters are prone to hydrolysis or oxidation during storage, leading to a decline in aroma and sweetness.

[0063] Since 2,2,6-trimethylcyclohexanone, trans-2-nonenal, and dihydroactinol are key flavor compounds that accumulate during aging in tea and polyphenol-rich plants, from Figure 3 The changes in the content of key substances show that the contents of all three gradually increased with the extension of treatment time (10–60 days). Among them, 2,2,6-trimethylcyclohexanone, a typical "aging marker" in red wine, increased from 19.05 μg / kg at 10 days to 33.99 μg / kg at 60 days in this study, exhibiting an accumulation trend similar to that during natural aging. trans-2-nonenal, a typical aging flavor compound, reached a content of 31.14 μg / kg at 60 days, a significant increase compared to 10 days, demonstrating its crucial role in the formation of aged aroma. Dihydroactinol, an important potential marker for the formation of woody aroma in aged tea, also continuously increased with time in the experiment (from 8.52 μg / kg at 10 days to 17.43 μg / kg at 60 days), highly consistent with the pattern observed in previous studies distinguishing between new and aged white tea.

[0064] Based on this, the ACI values ​​of the three key aroma compounds mentioned above were analyzed (see reference). Figure 4Aroma Character Impact (ACI) is an important indicator for measuring the contribution of a particular aroma compound to the overall aroma. It considers not only the relative content of compounds but also their olfactory threshold for weighted calculation, thus more accurately reflecting the impact of substances on actual sensory perception. ACI analysis can identify and confirm dominant aroma compounds, providing a basis for the analysis of aged tea aroma characteristics and the screening of key biomarkers. The results showed that with prolonged treatment time, the ACI values ​​of 2,2,6-trimethylcyclohexanone, trans-2-nonenal, and dihydroactinolone all gradually increased, reaching 0.88%, 0.81%, and 0.45% respectively at 60 days, significantly higher than at 10 days. Among them, the ACI values ​​of 2,2,6-trimethylcyclohexanone and trans-2-nonenal significantly exceeded 0.5% after 40 days, indicating that they played a decisive role in the overall formation of aged aroma. Although the ACI value of dihydroactinolone was relatively low, it continued to increase and remained above 0.1%, which is highly consistent with its role as a contributor to woody aroma characteristics during the aging process of white tea. Combining the changes in content with the ACI analysis results, it can be seen that the experimental group showed obvious aged aroma in the 30-60 day stage, thus verifying that this process can effectively simulate the accumulation of key aroma substances and sensory performance of natural aging in a short period of time.

[0065] Figure 4 For the comparison of key dark matter ACI values, different varieties, production areas, and seasons will have significant differences in the content of dihydroactinolide, a carotenoid oxidation degradation product in tea. The corresponding year cannot be directly proved by comparing data (experimental group and aged tea in other literature). Therefore, it can only be analyzed by combining the functional relationship and trend between different data groups with sensory evaluation and compound ACI values.

[0066] In this study, the inventors compared the changes in dihydroactinol content in tea obtained by the above method (designated as the experimental group) with those in naturally aged black tea and white tea samples (existing literature [1], [2]). The results are shown in Table 1. It can be seen that during the treatment period of 10 to 50 days, the content of this substance (dihydroactinol) in the experimental group increased from 8.52 μg / kg to 14.84 μg / kg, showing a significant upward trend overall, and showed a high correlation with both types of naturally aged samples. Correlation analysis showed that the correlation coefficient between the experimental group and the naturally aged black tea group was r = 0.972 (p < 0.01), and the correlation coefficient between the experimental group and the naturally aged white tea group was r = 0.974 (p < 0.05), both reaching a highly significant level. This indicates that the experimental treatment can not only induce the accumulation of this key aroma substance, but also has a dynamic law that is highly consistent with the natural aging process.

[0067] Table 1 Comparison of Key Substance Contents

[0068]

[0069] [1]Tao, Meng, Xiao et al. Effect of 1-20years storage on volatiles and aromaof Keemun congou black tea by solvent extraction-solid phase extraction-gaschromatography-mass spectrometry[J]. LWT-FOOD SCIENCE AND TECHNOLOGY, 2021,136.

[0070] [2] Huang Wei. A Study on the Flavor and Quality of Aged Zhenghe White Tea [D], 2024.

[0071] The above description is only a part of the embodiments of the present invention and does not limit the scope of protection of the present invention. Any equivalent device or equivalent process transformation made based on the content of the present invention specification and drawings, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for enhancing the flavor of aged tea using a saturated salt solution, characterized in that, It includes: A food-grade saturated salt solution is placed in a sealable cavity environment, and the temperature and water activity of the cavity environment are brought to the preset requirements. Then, tea leaves with a preset moisture content are placed in the cavity environment and sealed. With the help of a constant temperature and humidity device, the tea leaves are left to stand for a preset time under constant temperature, controlled humidity, and light-proof conditions to allow the tea leaves to age and develop a aged tea flavor.

2. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 1, characterized in that, The food-grade saturated salt solution is prepared from food-grade sodium nitrate or sodium chloride.

3. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 1 or 2, characterized in that, A food-grade saturated salt solution is placed in a sealable cavity environment, with the temperature of the cavity maintained at 25±2℃ and the water activity reaching 0.740~0.

760.

4. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 3, characterized in that, The moisture content of the tea leaves to be treated is 3% to 5%.

5. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 4, characterized in that, The tea leaves to be processed are also pre-treated, which includes drying the tea leaves at a temperature of 40-50°C until their moisture content is 3%-5%.

6. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 1, characterized in that, When the tea leaves to be processed are placed in the cavity environment, they are also placed in a food-grade breathable bag.

7. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 3, characterized in that, The settling period is 10 to 90 days.

8. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 7, characterized in that, The settling period is 30 to 90 days. During the settling period, the cavity environment is opened for ventilation for 30 minutes every 10 days, and then it is resealed and the constant temperature, humidity and light-proof conditions are maintained.

9. The method for enhancing the flavor of aged tea using a saturated salt solution as described in claim 3, characterized in that, After the tea leaves have been aged, their moisture content is tested. If the moisture content exceeds the preset value, the leaves are dried at a temperature of 40-70°C until the moisture content is lower than the preset value.

10. A type of aged tea with a distinctive flavor, characterized in that... It is prepared by the method described in any one of claims 1 to 9, wherein the tea is white tea, oolong tea, black tea, dark tea, green tea, yellow tea, or jasmine tea.

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