Processing method for increasing content of non-ester EPSF compounds in white tea

Abstract

The invention discloses a processing method for increasing the content of non-ester EPSF compounds in white tea, and belongs to the technical field of tea processing. The method comprises the following steps: taking white tea, carrying out high-temperature and high-pressure steam treatment, spreading and cooling treatment and drying treatment, and sequentially carrying out normal-pressure steaming treatment, brick pressing treatment, floating treatment and drying and aroma enhancing treatment on the dried white tea. According to the tea processing method, the reaction of theanine and catechin can be promoted to form an EPSF compound through high-temperature and high-pressure steam treatment, ester type EPSF can be promoted to be degraded and converted into non-ester type EPSF through floating treatment, the effect of increasing the content of the non-ester type EPSF compound in white tea is remarkable, and the content can be increased by more than 10 times.

Description

Technical Field

[0001] The invention belongs to the technical field of tea processing, and particularly relates to a processing method for increasing the content of non-ester EPSF compounds in white tea. Background Art

[0002] White tea is one of the six traditional teas in my country. It is a slightly fermented tea with the effects of reducing fire and inflammation, anti-oxidation, anti-radiation, anti-mutation, regulating blood lipids, regulating immune function, and preventing cardiovascular and cerebrovascular diseases. White tea (old white tea) that has been stored for a long time is considered to have stronger pharmacological effects and is often used by the people as a good medicine for reducing fire and inflammation and treating colds. According to research, old white tea contains a high content of characteristic components of N-ethyl-2-pyrrolidone-substituted catechins (EPSF). EPSF is a class of catechin derivatives. In recent years, studies have shown that EPSF compounds have a wide range of biological activities, such as good protection against hydrogen peroxide-induced human microvascular endothelial cell damage, suggesting that EPSF components may have anti-cardiovascular disease effects; it can inhibit the formation of advanced glycation end products, suggesting that EPSF components may have the effect of preventing the occurrence and development of diabetes; in addition, EPSF compounds have been found to have antioxidant, anti-inflammatory, acetylcholinesterase activity inhibition, and α-glucosidase activity inhibition. Depending on whether they contain galloyl groups, EPSF compounds can be divided into ester-type EPSFs (R-EGCG-cThea, S-EGCG-cThea, R-ECG-cThea, S-ECG-cThea, etc.) and non-ester-type EPSFs (R-EGC-cThea, S-EGC-cThea, R-EC-cThea, S-EC-cThea, etc.).

[0003] The applicant applied for a Chinese invention patent for a processing method for increasing the content of R-EGCG-cThea in white tea on January 29, 2019, and its publication number is 109757569 A. The invention specifically discloses taking white tea and subjecting it to high-temperature and high-pressure steam treatment; cooling treatment; drying treatment; storage treatment under oxygen-rich conditions at room temperature; and aroma treatment. The present invention is a tea processing method that can significantly increase the content of R-EGCG-cThea in white tea, and has the following advantages: catechin components substituted by 8-CN-ethyl-2-pyrrolidone have good biological activity and health effects, and increase the content of such components represented by R-EGCG-cThea in white tea, which has originality and great market potential; the tea processing method has a significant effect on increasing the content of R-EGCG-cThea in white tea, and the increase can reach 5-50 times; the processing method has the advantages of simple operation and low cost, and has broad application prospects in the field of white tea processing.

[0004] However, studies have shown that non-ester catechins are less bitter and have a sweet aftertaste than ester catechins, so the applicant speculates that non-ester EPSF may contribute better to the flavor quality of tea than ester EPSF. Based on this, developing a tea processing method that can significantly increase the content of non-ester EPSF in white tea is expected to further improve the health benefits and flavor quality of white tea. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to design and provide a technical solution for a processing method for increasing the content of non-ester EPSF compounds in white tea. The method has the advantages of simple operation, low cost, significant effect, etc.

[0006] The present invention is specifically implemented by the following technical solutions: The invention provides a processing method for increasing the content of non-ester EPSF compounds in white tea, comprising the following steps: taking the white tea and subjecting it to high-temperature and high-pressure steam treatment, cooling treatment, drying treatment, normal-pressure steaming treatment, brick pressing treatment, blooming treatment and drying and aroma treatment.

[0007] Furthermore, the high-temperature and high-pressure steam treatment is specifically carried out in a temperature-controllable high-pressure closed device, with a high temperature of 100°C-150°C, a high pressure of 0.15-0.5MPa, and a steam treatment time of 5-120min.

[0008] Furthermore, the cooling treatment is specifically as follows: spreading at a room temperature of 20-30°C, with a leaf thickness of 3-10cm and a spreading time of 0.5-24h.

[0009] Furthermore, the drying process is specifically carried out in an oven at a temperature of 60-110° C. for a time of 10-120 min.

[0010] Furthermore, the atmospheric pressure steaming treatment is specifically as follows: the pressure is atmospheric pressure, the steam temperature is 100° C., and the time is 30-60 seconds.

[0011] Furthermore, the brick pressing process specifically includes: pressing the white tea after the normal pressure steaming process into bricks, and the mass of each white tea brick is 300-1000 grams.

[0012] Furthermore, the "flowering" treatment is specifically as follows: placing the white tea brick in a flowering room inoculated with Eurotium cristatum for 12-24 days of flowering.

[0013] Further, the flower blooming treatment is specifically as follows: ① controlling the temperature in the flower blooming room to 31-33° C. and the humidity to 70%-80% for 3-7 days; ② controlling the temperature in the flower blooming room to 28-31° C. and the humidity to 80%-85% for 2-4 days; ③ controlling the temperature in the flower blooming room to 25-28° C. and the humidity to 80%-85% for 2-4 days; ④ controlling the temperature in the flower blooming room to 25-28° C. and the humidity to 76%-83% for 5-9 days.

[0014] Furthermore, the drying and aroma extraction is specifically: using a tea aroma extraction machine to dry and aroma extract at a temperature of 70-100° C. for 20-60 minutes.

[0015] The beneficial effects of the present invention are: 1) Non-ester EPSF compounds have good biological activity and health effects. Increasing the content of non-ester EPSF compounds in white tea has originality and great market potential; 2) In this tea processing method, high temperature and high pressure steam treatment can promote the reaction between theanine and catechins to form EPSF compounds, and flowering treatment can promote the degradation and conversion of ester-type EPSF into non-ester-type EPSF, which has a significant effect on increasing the content of non-ester-type EPSF compounds in white tea, with the increase ratio reaching more than 10 times; 3) This processing method has the advantages of simple operation and low cost, and has broad application prospects in the field of white tea processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 These are the chemical structural formulas of the four main non-ester EPSF compounds in white tea.

[0017] Figure 2 These are photos of dry white tea and tea soup before and after being processed using the technology of the present invention. DETAILED DESCRIPTION

[0018] The following is a detailed description in conjunction with the embodiments: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0019] Example 1

[0020] 1) Collect 10 kg of Shoumei white tea; 2) Steam the Shoumei white tea at 125°C and 0.18MPa for 10 minutes; 3) Cool at 25℃, with a leaf thickness of 5cm and a spreading time of 3h; 4) Dry the cooled Shoumei white tea in an oven at a temperature of 90°C for 40 minutes; 5) The dried Shoumei white tea is steamed at normal pressure, with a steam temperature of 100°C and a time of 45 seconds.

[0021] 6) The white tea is pressed into bricks, and each white tea brick weighs 500 grams.

[0022] 7) Place the white tea bricks in a flowering room inoculated with Eurotium cristatum for flowering, and control the temperature in the flowering room to 32°C and the humidity to 75% for 4 days; adjust the temperature in the flowering room to 30°C and the humidity to 84% for 3 days; adjust the temperature in the flowering room to 28°C and the humidity to 85% for 3 days; adjust the temperature in the "flowering" room to 28°C and the humidity to 80% for 6 days; the above is a total of 16 days.

[0023] 8) Dry the bloomed white tea bricks to enhance the aroma at 90°C for 30 minutes.

[0024] 9.5 kg of Shoumei white tea was obtained. As shown in Table 1, the content of non-ester EPSF compounds increased from 0.1221 mg / g to 2.0233 mg / g by UHPLC-Q-Exactive absolute quantitative analysis, with a change of 16.6 times. Among them, the four main non-ester EPSF compounds 8- CR -EGC-cThea, 8- CS -EGC-cThea, 8- CR -EC-cThea,8- CS -EC-cThea contents were 17.9, 20.0, 15.3 and 14.2 times those before treatment, respectively.

[0025] Figure 1 These are the chemical structural formulas of the four main non-ester EPSF compounds in white tea.

[0026] Figure 2 The photos of dry white tea and tea soup before and after the treatment of the present invention are shown in Figure 1. Compared with before the treatment, the surface of the dry white tea has "golden flowers" formed by Eurotium cristatum, and the color of the tea soup changes from light yellow to orange-yellow to brown.

[0027] Table 1. Changes in the contents of main non-ester EPSF compounds before and after treatment with the technology of the present invention

[0028] Example 2

[0029] 1) Collect 10 kg of Shoumei white tea; 2) Steam the Shoumei white tea at 150°C and 0.32MPa for 60 minutes; 3) Cool at 30℃ room temperature, with the leaf thickness of 10cm and the spreading time of 15h; 4) Dry the cooled Shoumei white tea in an oven at a temperature of 100°C for 10 minutes; 5) The dried Shoumei white tea is steamed at normal pressure, with a steam temperature of 100°C and a time of 60 seconds.

[0030] 6) The white tea is pressed into bricks, and each white tea brick weighs 1000 grams.

[0031] 7) Place the white tea bricks in a flowering room inoculated with Eurotium cristatum for flowering, and control the temperature in the flowering room to 31°C and the humidity to 70% for 7 days; adjust the temperature in the flowering room to 31°C and the humidity to 85% for 4 days; adjust the temperature in the flowering room to 25°C and the humidity to 80% for 3 days; adjust the temperature in the "flowering" room to 25°C and the humidity to 83% for 5 days; the above is a total of 20 days.

[0032] 8) Dry the bloomed white tea bricks to extract the aroma at a temperature of 100°C for 20 minutes.

[0033] 9.5 kg of Shoumei white tea was obtained. As shown in Table 2, the absolute quantitative analysis by liquid chromatography-high resolution mass spectrometry UHPLC-Q-Exactive showed that the content of non-ester EPSF compounds increased from 0.1221 mg / g to 1.6593 mg / g, with a change of 13.6 times. Among them, the four main non-ester EPSF compounds 8- CR -EGC-cThea, 8- CS -EGC-cThea, 8- CR -EC-cThea,8- CS -EC-cThea contents were 14.4, 17.4, 12.8 and 10.9 times those before treatment, respectively.

[0034] Table 2. Changes in the contents of main non-ester EPSF compounds before and after treatment with the technology of the present invention

[0035] Example 3

[0036] 1) Collect 10 kg of White Peony White Tea; 2) Steam the white peony tea at 100°C and 0.5 MPa for 5 minutes; 3) Cool at room temperature of 20℃, with a leaf thickness of 5cm and a spreading time of 24h; 4) Dry the cooled white peony white tea in an oven at a drying temperature of 60°C for 120 minutes; 5) The dried white peony white tea is steamed at normal pressure, with a steam temperature of 100°C and a time of 30 seconds.

[0037] 6) The white tea is pressed into bricks, and each white tea brick weighs 1000 grams.

[0038] 7) Place the white tea bricks in a "flowering" room inoculated with Eurotium cristatum for "flowering", and control the temperature in the flower-blooming room to 33°C and the humidity to 80% for 3 days; adjust the temperature in the flower-blooming room to 28°C and the humidity to 80% for 2 days; adjust the temperature in the flower-blooming room to 25°C and the humidity to 85% for 2 days; adjust the temperature in the "flowering" room to 25°C and the humidity to 76% for 5 days; the above is a total of 12 days.

[0039] 8) Dry the bloomed white tea bricks to enhance the aroma at a temperature of 80°C for 60 minutes.

[0040] 9.5 kg of white peony tea was obtained. As shown in Table 3, the absolute quantitative analysis by liquid chromatography-high resolution mass spectrometry UHPLC-Q-Exactive showed that the content of non-ester EPSF compounds increased from 0.1156 mg / g to 2.1665 mg / g, with a change of 18.7 times. Among them, the four main non-ester EPSF compounds 8- CR -EGC-cThea, 8- CS -EGC-cThea, 8- CR -EC-cThea,8- CS -EC-cThea contents were 21.2, 22.2, 16.5 and 16.2 times those before treatment, respectively.

[0041] Table 3. Changes in the contents of main non-ester EPSF compounds before and after treatment with the technology of the present invention

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A processing method for increasing the content of non-ester EPSF compounds in white tea, comprising the following steps: The white tea is subjected to high-temperature and high-pressure steam treatment, cooling treatment, and drying treatment, wherein the dried white tea is sequentially subjected to normal-pressure steaming treatment, brick pressing treatment, flower development treatment, and drying and aroma treatment.

2. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The high temperature and high pressure steam treatment is specifically carried out in a temperature-controllable high pressure closed device, with a high temperature of 100-150° C., a high pressure of 0.15-0.5 MPa, and a steam treatment time of 5-120 min.

3. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The cooling treatment specifically includes: spreading at a room temperature of 20-30°C, with a leaf thickness of 3-10cm and a spreading time of 0.5-24h.

4. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The drying process is specifically carried out in an oven at a temperature of 60-110° C. for a time of 10-120 min.

5. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The atmospheric pressure steaming treatment specifically includes: atmospheric pressure, steam temperature of 100° C., and time of 30-60 seconds.

6. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The brick pressing process specifically comprises: pressing the white tea after the normal pressure steaming process into bricks, and the mass of each white tea brick is 300-1000 grams.

7. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The flowering treatment is specifically as follows: placing the white tea brick in a flowering room inoculated with Eurotium cristatum for 12-24 days.

8. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 7, characterized in that: The flower-growing treatment is specifically as follows: ① controlling the temperature in the flower-growing room to 31-33° C. and the humidity to 70%-80% for 3-7 days; ② controlling the temperature in the flower-growing room to 28-31° C. and the humidity to 80%-85% for 2-4 days; ③ controlling the temperature in the flower-growing room to 25-28° C. and the humidity to 80%-85% for 2-4 days; ④ controlling the temperature in the flower-growing room to 25-28° C. and the humidity to 76%-83% for 5-9 days.

9. A processing method for increasing the content of non-ester EPSF compounds in white tea according to claim 1, characterized in that: The drying and aroma-enhancing method specifically comprises: using a tea aroma-enhancing machine to dry and aroma-enhance the tea at a temperature of 70-100° C. for 20-60 minutes.

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