Agilawood tea and preparation method thereof

Abstract

The invention provides agilawood tea and a preparation method thereof, and belongs to the technical field of tea product processing. The agilawood tea is prepared from agilawood leaves, fiveleaf gynostemma herb, sweet-scented osmanthus and a momordica grosvenori extract. Firstly, the agilawood leaves and the fiveleaf gynostemma herb are subjected to fixation and then are mixed with the sweet-scented osmanthus, and rolling is performed to obtain compound tea; mixing siraitia grosvenorii and ethyl acetate, and performing ultrasonic extraction, filtration, concentration and evaporation to dryness to obtain a siraitia grosvenorii extract; and finally, mixing the compound tea and the fructus momordicae extract, fermenting, and drying to obtain the agilawood tea. Osmanthus fragrans is added into the agilawood tea, so that the fragrance of the osmanthus fragrans is reserved, and the taste is improved; the siraitia grosvenorii extract is added, so that sweetness can be provided, and the lung moistening function of the tea can be enhanced; and the added gynostemma pentaphylla has the efficacy of decreasing internal heat. Through the mode of combining low-temperature fermentation with gradient drying, the content of total flavonoids in the agilawood tea can be increased, and bitter taste of the agilawood tea can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of tea product processing, and in particular to agarwood tea and a preparation method thereof. Background Art

[0002] Agarwood leaves are rich in active ingredients such as flavonoids, polysaccharides and volatile oils, and have anti-inflammatory and analgesic effects, laxative and detoxification, sleep-aiding, blood sugar and lipid-lowering, qi-invigorating and essence-benefiting, and anti-tumor effects. In recent years, tea products made from agarwood leaves have gradually attracted attention, but tea products in the prior art have the following problems: traditional agarwood tea uses agarwood leaves as raw materials, the tea soup has a light aroma and a slightly bitter taste, and the palatability is poor; tea leaves prepared using agarwood leaves alone have a limited total flavonoid content and a free radical scavenging rate of less than 60%; in the prior art, the preparation of agarwood tea uses high temperature killing or long fermentation time, which leads to the degradation of flavonoids and the loss of effective ingredients. Therefore, it is of great significance to study a kind of agarwood tea and its preparation method to improve the total flavonoid content. Summary of the invention

[0003] The object of the present invention is to provide an agarwood tea and a preparation method thereof, so as to solve the problems in the prior art that tea products using agarwood leaves as raw materials have a bitter taste and a low total flavonoid content.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides an agarwood tea, which is prepared from agarwood leaves, gynostemma pentaphyllum, osmanthus and monk fruit extracts.

[0006] Preferably, the mass ratio of the extracts of agarwood leaves, gynostemma pentaphyllum, osmanthus and momordica grosvenori is 60-80:8-15:5-10:1-5.

[0007] The present invention provides a method for preparing the above-mentioned agarwood tea, comprising the following steps:

[0008] (1) fixing the agarwood leaves and gynostemma pentaphyllum, and then mixing and rolling them with osmanthus to obtain a composite tea;

[0009] (2) mixing the monk fruit and ethyl acetate, performing ultrasonic extraction, filtering, concentrating and evaporating to obtain a monk fruit extract;

[0010] (3) The compound tea and the monk fruit extract are mixed, fermented, and dried to obtain agarwood tea.

[0011] Preferably, in step (1), the killing is performed by steam, the steam temperature is 70 to 90° C., and the killing time is 1 to 5 minutes.

[0012] Preferably, in step (1), the kneading time is 20 to 30 minutes.

[0013] Preferably, in step (2), the solid-liquid ratio of the monk fruit and ethyl acetate is 1:10-20; the temperature of the ultrasonic extraction is 60-80°C, and the time of the ultrasonic extraction is 20-40 min.

[0014] Preferably, in step (3), the relative humidity during fermentation is 60-80%, the temperature is 30-40° C., and the fermentation time is 4-6 hours.

[0015] Preferably, in step (3), the drying comprises primary drying and secondary drying.

[0016] Preferably, the initial baking temperature is 30-50° C. and the time is 10-30 min.

[0017] Preferably, the re-drying temperature is 60-70° C., and the re-drying is stopped until the water content is ≤5%.

[0018] Beneficial effects of the present invention:

[0019] (1) Osmanthus fragrans is added to the agarwood tea of ​​the present invention, which retains the fragrance of osmanthus fragrans and improves the taste; the addition of monk fruit extract can not only provide sweetness but also enhance the lung moistening function of tea; the addition of gynostemma pentaphyllum has the effect of reducing internal heat.

[0020] (2) The present invention uses agarwood leaves, osmanthus, gynostemma pentaphyllum and monk fruit extracts as raw materials, combined with low-temperature fermentation and gradient drying methods, which can not only increase the content of total flavonoids in agarwood tea, but also avoid the bitterness of agarwood tea. DETAILED DESCRIPTION

[0021] The invention provides an agarwood tea, which is prepared from agarwood leaves, gynostemma pentaphyllum, osmanthus and monk fruit extracts.

[0022] In the present invention, the mass ratio of the extracts of agarwood leaves, gynostemma pentaphyllum, osmanthus and momordica grosvenori is 60-80:8-15:5-10:1-5, preferably 65-75:10-12:7-9:2-4, and more preferably 70:10:10:3.

[0023] The present invention also provides a method for preparing the above-mentioned agarwood tea, comprising the following steps:

[0024] (1) fixing the agarwood leaves and gynostemma pentaphyllum, and then mixing and rolling them with osmanthus to obtain a composite tea;

[0025] (2) mixing the monk fruit and ethyl acetate, performing ultrasonic extraction, filtering, concentrating and evaporating to obtain a monk fruit extract;

[0026] (3) The compound tea and the monk fruit extract are mixed, fermented, and dried to obtain agarwood tea.

[0027] In the present invention, in step (1), the killing is carried out by steam killing, the temperature of the steam is 70-90°C, preferably 75-85°C, more preferably 80°C; the killing time is 1-5 min, preferably 2-4 min, more preferably 3 min.

[0028] In the present invention, in step (1), the kneading time is 20 to 30 minutes, preferably 20 minutes, 25 minutes, or 30 minutes.

[0029] In the present invention, in step (2), the solid-liquid ratio of the monk fruit and ethyl acetate is 1:10-20, preferably 1:12-18, and more preferably 1:15; the temperature of the ultrasonic extraction is 60-80°C, preferably 65-75°C, and more preferably 70°C; the time of the ultrasonic extraction is 20-40min, preferably 25-35min, and more preferably 30min.

[0030] In the present invention, in step (3), the relative humidity during fermentation is 60-80%, preferably 70%; the temperature is 30-40°C, preferably 35°C; and the time is 4-6h, preferably 5h.

[0031] In the present invention, in step (3), the drying includes primary drying and secondary drying.

[0032] In the present invention, the temperature of the initial baking is 30-50° C., preferably 40° C., and the time is 10-30 min, preferably 20 min.

[0033] In the present invention, the re-drying temperature is 60-70° C., preferably 65° C., and the re-drying is stopped until the water content is ≤5%.

[0034] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0035] Example 1

[0036] 7kg of agarwood leaves and 1kg of young leaves of Gynostemma pentaphyllum were picked, treated with cold air, and then placed in a steam-fixing machine for fixing: the vacuum degree in the steam-fixing machine was controlled to be 0.5MPa, the temperature of the steam was 70°C, and the fixing was performed for 3min; after the fixing was completed, 1kg of osmanthus was added, and the leaves were rolled for 20min to obtain a compound tea;

[0037] The monk fruit is dried, crushed, and passed through 100 meshes to obtain monk fruit powder, which is then added to ethyl acetate at a solid-liquid ratio of 1:15. The temperature of the mixture is heated to 70°C, ultrasonic extraction is performed for 30 minutes, and the ultrasonic extraction is completed. The filtrate is concentrated and evaporated at 60°C to obtain the monk fruit extract.

[0038] Add 0.3 kg of monk fruit extract to the above-mentioned compound tea, ferment for 5 hours at a relative humidity of 70% and a temperature of 35°C, and transfer to an oven for drying after fermentation: the initial baking temperature is 40°C for 20 minutes, and the secondary baking temperature is 65°C, until the moisture content is ≤5%, to obtain agarwood tea, which can be bagged.

[0039] Example 2

[0040] 6 kg of agarwood leaves and 1.5 kg of young leaves of Gynostemma pentaphyllum were picked, treated with cold air, and then placed in a steam fixing machine for fixing: the vacuum degree in the steam fixing machine was controlled to be 0.5 MPa, the temperature of the steam was 90°C, and the fixing was performed for 1 min; after the fixing was completed, 0.5 kg of osmanthus was added, and the leaves were rolled for 30 min to obtain a composite tea;

[0041] The monk fruit is dried, crushed, and passed through 100 meshes to obtain monk fruit powder, which is then added to ethyl acetate at a solid-liquid ratio of 1:20. The temperature of the mixture is heated to 60°C, ultrasonic extraction is performed for 20 minutes, and the ultrasonic extraction is completed. The filtrate is concentrated and evaporated at 60°C to obtain the monk fruit extract.

[0042] Add 0.1 kg of monk fruit extract to the above-mentioned compound tea, ferment for 6 hours at a relative humidity of 80% and a temperature of 30°C, and transfer to an oven for drying after fermentation: the initial baking temperature is 30°C for 30 minutes, and the secondary baking temperature is 60°C, until the moisture content is ≤5%, to obtain agarwood tea, which can be bagged.

[0043] Example 3

[0044] 8kg of agarwood leaves and 0.8kg of young leaves of Gynostemma pentaphyllum were picked, treated with cold air, and then placed in a steam fixing machine for fixing: the vacuum degree in the steam fixing machine was controlled to be 0.5MPa, the temperature of the steam was 80°C, and the fixing was performed for 5min; after the fixing was completed, 0.8kg of osmanthus was added, and the mixture was rolled for 25min to obtain a composite tea;

[0045] The monk fruit is dried, crushed, and passed through 100 meshes to obtain monk fruit powder, which is then added to ethyl acetate at a solid-liquid ratio of 1:10. The temperature of the mixture is heated to 80°C, ultrasonic extraction is performed for 40 minutes, and the ultrasonic extraction is completed. The filtrate is concentrated and evaporated at 60°C to obtain the monk fruit extract.

[0046] Add 0.5 kg of monk fruit extract to the above-mentioned compound tea, ferment for 4 hours at a relative humidity of 60% and a temperature of 40°C, and transfer to an oven for drying after fermentation: the initial baking temperature is 50°C for 10 minutes, and the secondary baking temperature is 70°C, until the moisture content is ≤5%, to obtain agarwood tea, which can be bagged.

[0047] Comparative Example 1

[0048] The difference from Example 1 is that no Gynostemma pentaphyllum was added, and other conditions were the same.

[0049] Comparative Example 2

[0050] The difference from Example 1 is that no monk fruit extract is added, and other conditions are the same.

[0051] Comparative Example 3

[0052] The difference from Example 1 is that sweet osmanthus is not added, and other conditions are the same.

[0053] Take 1 g of the agarwood tea of ​​Examples 1 to 3 and Comparative Examples 1 to 3, brew it twice with 90° C. water at a tea-to-water ratio of 1:50, each brewing for 30 minutes, filter and mix the tea soup for standby use.

[0054] Take rutin standard solution (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0mL), water (blank control) and tea soup 1.0mL each into a test tube, add 70% (volume fraction) ethanol solution to 5mL, add 0.4mL of 50g / L sodium nitrite aqueous solution, mix well and let stand for 6min, add 0.4mL of 100g / L aluminum nitrate aqueous solution, mix well and let stand for 6min, add 4mL of 40g / L sodium hydroxide aqueous solution, mix well and react for 15min, and measure its absorbance at a wavelength of 510nm. Draw a standard curve based on different concentrations of rutin standard solution and its measurement results, and calculate the content of total flavonoids in the tea soup sample. The results are shown in Table 1:

[0055] Table 1 Measurement results of Examples 1 to 3 and Comparative Examples 1 to 3

[0056] serial number Total flavonoids content (mg / g) Example 1 17.2 Example 2 16.5 Example 3 15.8 Comparative Example 1 8.3 Comparative Example 2 12.1 Comparative Example 3 13.5

[0057] As can be seen from Table 1, the flavonoid content of the agarwood tea of ​​Examples 1 to 3 is significantly higher than that of Comparative Examples 1 to 3, and can reach up to 17.2 mg / g.

[0058] 10 professionally trained sensory evaluators were selected to evaluate the tea soup. No irritating food (such as coffee, spicy food) was consumed within 2 hours before the test. The test was conducted in an independent laboratory without strong odor, constant temperature and soft light. The evaluation indexes and scoring standards are shown in Table 2:

[0059] Table 2 Evaluation indicators and scoring criteria

[0060]

[0061]

[0062] Testing process:

[0063] 1. Initial evaluation: Each judge smells the tea aroma in turn and records his or her first impression.

[0064] 2. Drinking: Sip the tea in small sips, hold it on the tongue for 5 seconds and swallow it, and evaluate the taste and aftertaste.

[0065] 3. Re-evaluation: Repeat the test after an interval of 10 minutes and take the average of the two scores to reduce individual bias.

[0066] 4. Data statistics: Remove extreme values ​​(if the mean difference is > ±2σ), calculate the comprehensive score and sort, the statistical results are shown in Table 3:

[0067] Table 3 Sensory evaluation results of Examples 1 to 3 and Comparative Examples 1 to 3

[0068] serial number Final rating Example 1 9 Example 2 8 Example 3 8 Comparative Example 1 6 Comparative Example 2 5 Comparative Example 3 5

[0069] It can be seen from Table 3 that the agarwood tea of ​​Examples 1 to 3 has a better taste, with the highest score being 9 points.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A kind of agarwood tea, characterized in that: The agarwood tea is prepared from agarwood leaves, gynostemma pentaphyllum, osmanthus and monk fruit extracts.

2. The agarwood tea according to claim 1, characterized in that The mass ratio of the agarwood leaf, gynostemma pentaphyllum, osmanthus and momordica grosvenori extracts is 60-80:8-15:5-10:1-5.

3. The method for preparing agarwood tea according to claim 1 or 2, characterized in that: The steps include: (1) fixing the agarwood leaves and gynostemma pentaphyllum, and then mixing and rolling them with osmanthus to obtain a composite tea; (2) mixing the monk fruit and ethyl acetate, performing ultrasonic extraction, filtering, concentrating and evaporating to obtain a monk fruit extract; (3) The compound tea and the monk fruit extract are mixed, fermented, and dried to obtain agarwood tea.

4. The method for preparing agarwood tea according to claim 3, characterized in that: In step (1), the greening is performed by steam, the temperature of the steam is 70 to 90° C., and the greening time is 1 to 5 minutes.

5. The method for preparing agarwood tea according to claim 3 or 4, characterized in that: In step (1), the kneading time is 20 to 30 minutes.

6. The method for preparing agarwood tea according to claim 5, characterized in that: In step (2), the solid-liquid ratio of the monk fruit and ethyl acetate is 1:10-20; the temperature of the ultrasonic extraction is 60-80° C., and the time of the ultrasonic extraction is 20-40 min.

7. The method for preparing agarwood tea according to claim 4 or 6, characterized in that: In step (3), the relative humidity during fermentation is 60-80%, the temperature is 30-40° C., and the fermentation time is 4-6 hours.

8. The method for preparing agarwood tea according to claim 7, characterized in that: In step (3), the drying includes primary drying and secondary drying.

9. The method for preparing agarwood tea according to claim 8, characterized in that: The temperature of the initial baking is 30-50° C. and the time is 10-30 minutes.

10. The method for preparing agarwood tea according to claim 8 or 9, characterized in that: The re-drying temperature is 60-70° C., and the re-drying is stopped until the water content is ≤5%.

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