High-quality tea processing technology

Abstract

The invention discloses a high-quality tea leaf processing technology, and belongs to the technical field of tea leaf processing, and the high-quality tea leaf processing technology comprises the following steps: (1) fresh leaf pretreatment; (2) performing microwave fixation; (3) rolling; and (4) freeze drying. According to the high-quality tea leaf processing technology provided by the invention, the tea leaf processing technology is improved, so that infection of microorganisms is effectively avoided, a very good killing effect on mold, escherichia coli and the like existing in fresh leaves is achieved, and meanwhile, decomposition of bifenthrin, imidacloprid and carbendazim can be promoted, so that the quality of tea leaves is improved, and the quality of the tea leaves is improved. And the health of consumers is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of tea processing, and particularly relates to a high-quality tea processing technology. Background Art

[0002] In recent years, the problem of tea hygiene quality has become a prominent issue restricting China's export expansion. Currently, while the international community further raises the requirements for pesticide residues and heavy metal limits in tea, control requirements for various harmful microorganisms in tea have also been put forward. The numbers of molds and Escherichia coli have also become two important control indicators for tea hygiene quality. Processing is an important factor affecting the safety of tea hygiene quality. Processing operations have a certain removal effect on chemical pesticides existing in fresh tea leaves, and the degradation rate of residual pesticides in fresh tea leaves is generally between 50% and 80%. In addition, during the tea-making process, the material has high moisture, a long processing time, and a wide environmental contact surface, which is extremely likely to cause the contamination and massive reproduction of microorganisms (especially molds and bacteria). Chemical pesticides and microorganisms are the two most important aspects of tea hygiene quality safety. Currently, there are many research reports on the changes in the respective contents of chemical pesticides and microorganisms during the tea processing process, but there is less research on tea microorganisms, and most of them focus on one or two aspects, and there is no report on the comprehensive research of these two aspects. Therefore, it is of positive significance to improve the relative decomposition rate of chemical pesticides through the improvement of processing technology, avoid the infection of microorganisms, improve the safety level of tea hygiene quality, expand China's tea exports, and safeguard the health of consumers. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-quality tea processing technology to solve the deficiencies in the prior art.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A high-quality tea processing technology includes the following steps:

[0006] (1) Pretreatment of fresh tea leaves:

[0007] a. Place the fresh tea leaves in a bamboo utensil for spreading, and perform ultrasonic treatment while spreading;

[0008] b. Place the fresh tea leaves treated in operation a in a cold plasma device for cold plasma treatment, and take them out for standby after completion;

[0009] (2) Microwave fixation:

[0010] Place the fresh tea leaves pretreated in step (1) in a microwave fixation machine for microwave fixation treatment, and take out the tea leaves for standby after completion;

[0011] (3) Rolling:

[0012] Place the tea leaves after microwave fixation in step (2) into a rolling machine for rolling, and then perform wrapping rolling before setting aside.

[0013] (4) Freeze-drying:

[0014] Place the rolled tea leaves in step (3) into a vacuum freeze-drying chamber for vacuum drying treatment, and after completion, perform stem picking and packaging.

[0015] Furthermore, during the ultrasonic treatment in operation a of step (1), control the frequency of the ultrasonic wave to be 30 - 40 kHz.

[0016] Furthermore, during the withering treatment in operation a of step (1), wither until the moisture content of the fresh leaves is 70 - 80%.

[0017] Furthermore, during the cold plasma treatment in operation b of step (1), control the frequency to be 8 - 9 MHz, the power to be 100 - 120 W, and the air flow rate to be 200 - 240 mL / min.

[0018] By adopting the above technical solution, place the fresh leaves in a bamboo utensil for withering, and perform ultrasonic treatment during withering. Under the cavitation effect, acoustic streaming effect, and thermal effect of the ultrasonic wave, the pores of the fresh leaf cells open and close, promoting the loss of moisture, improving the withering efficiency. At the same time, under the action of the ultrasonic wave, the fresh leaf fibers are softened, laying a good foundation for subsequent rolling into strips and improving the tea quality. Then place it in a cold plasma device for cold plasma treatment. By controlling the technical parameters of the cold plasma treatment, improve the activity of the fresh leaf epidermal cells, cooperate with the ultrasonic treatment to strengthen, promote the decomposition of chemical pesticides, and prevent the invasion of microbial flora.

[0019] Furthermore, during the microwave fixation in step (2), control the power of the microwave to be 300 - 400 W.

[0020] By adopting the above technical solution, use microwave-assisted fixation. By controlling the power of the microwave, further promote the decomposition of chemical pesticides and inactivate the microbial flora existing in the tea leaves, thereby improving the tea quality.

[0021] Furthermore, during the vacuum drying treatment in step (4), control the vacuum degree to be 2 - 3 Pa, the freezing temperature to be -8 - -4 °C, the freezing time to be 8 - 12 min, the drying temperature to be 50 - 60 °C, and dry until the moisture content is 6 - 9%.

[0022] By adopting the above technical solution, perform vacuum freeze-drying treatment on the tea leaves after rolling, which can not only prevent the invasion of microbial flora but also prevent the loss of active ingredients in the tea leaves, and maintain good color and aroma.

[0023] The present invention has the following beneficial effects:

[0024] The present application provides a high-quality tea processing technology. By improving the tea processing technology, it effectively avoids the invasion of microorganisms, has a good killing effect on molds, Escherichia coli, etc. existing in fresh tea leaves, and can promote the decomposition of bifenthrin, imidacloprid, and carbendazim, thereby improving the quality of tea and ensuring the health of consumers. Description of the Drawings

[0025] Figure 1 It is a comparison chart of test data on the relative decomposition rate of chemical substances in the tea of each embodiment, comparative example, and control group in the specific implementation part of the present application. Specific Implementation Modes

[0026] Next, the technical solutions of the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Example 1

[0028] A high-quality tea processing technology includes the following steps:

[0029] (1) Pretreatment of fresh tea leaves:

[0030] a. Place the fresh tea leaves in a bamboo utensil for spreading, and perform ultrasonic treatment while spreading;

[0031] b. Place the fresh tea leaves treated in operation a in a cold plasma device for cold plasma treatment, and take them out for standby after completion;

[0032] (2) Microwave fixation:

[0033] Place the fresh tea leaves pretreated in step (1) in a microwave fixation machine for microwave fixation treatment, and take out the tea leaves for standby after completion;

[0034] (3) Rolling:

[0035] Place the tea leaves treated by microwave fixation in step (2) in a rolling machine for rolling, and then perform wrapping rolling and set aside;

[0036] (4) Freeze-drying:

[0037] Place the rolled tea leaves in step (3) in a vacuum freeze-drying oven for vacuum drying treatment, and then perform stem picking and packaging.

[0038] During the ultrasonic treatment described in operation a of step (1), control the frequency of the ultrasonic wave to 30 kHz.

[0039] During the spreading treatment described in operation a of step (1), spread until the moisture content of the fresh leaves is 70%.

[0040] During the cold plasma treatment described in operation b of step (1), control the frequency to 8 MHz, the power to 100 W, and the air flow rate to 200 mL / min.

[0041] During the microwave fixation described in step (2), control the power of the microwave to 300 W.

[0042] During the vacuum drying treatment described in step (4), control the vacuum degree to 2 Pa, the freezing temperature to -8 °C, the freezing time to 8 min, the drying temperature to 50 °C, and dry until the moisture content is 6%.

[0043] Example 2

[0044] A high-quality tea processing technology includes the following steps:

[0045] (1) Fresh leaf pretreatment:

[0046] a. Place the fresh leaves in a bamboo utensil for spreading, and perform ultrasonic treatment while spreading;

[0047] b. Place the fresh leaves treated in operation a in a cold plasma device for cold plasma treatment, and take them out for standby after completion;

[0048] (2) Microwave fixation:

[0049] Place the fresh leaves pretreated in step (1) in a microwave fixation machine for microwave fixation treatment, and take out the tea for standby after completion;

[0050] (3) Rolling:

[0051] Place the tea treated by microwave fixation in step (2) in a rolling machine for rolling, and then perform wrapping rolling and set aside;

[0052] (4) Freeze-drying:

[0053] Place the rolled tea in step (3) in a vacuum freeze-drying chamber for vacuum drying treatment, and then perform stem picking and packaging.

[0054] During the ultrasonic treatment described in operation a of step (1), control the frequency of the ultrasonic wave to 35 kHz.

[0055] During the spreading treatment described in operation a of step (1), spread until the moisture content of the fresh leaves is 75%.

[0056] During the cold plasma treatment described in operation b of step (1), the frequency is controlled at 8.5 MHz, the power is 110 W, and the gas flow rate is 220 mL / min.

[0057] During the microwave fixation described in step (2), the power of the microwave is controlled at 350 W.

[0058] During the vacuum drying treatment described in step (4), the vacuum degree is controlled at 2.5 Pa, the freezing temperature is -6 °C, the freezing time is 10 min, the drying temperature is 55 °C, and it is dried until the moisture content is 7.5%.

[0059] Example 3

[0060] A high-quality tea processing technology includes the following steps:

[0061] (1) Fresh leaf pretreatment:

[0062] a. Place the fresh leaves in a bamboo utensil for withering, and perform ultrasonic treatment during withering;

[0063] b. Place the fresh leaves treated in operation a in a cold plasma equipment for cold plasma treatment, and take them out for standby after completion;

[0064] (2) Microwave fixation:

[0065] Place the fresh leaves pretreated in step (1) in a microwave fixation machine for microwave fixation treatment, and take out the tea for standby after completion;

[0066] (3) Rolling:

[0067] Place the tea treated by microwave fixation in step (2) in a rolling machine for rolling, and then perform wrapping rolling and set aside;

[0068] (4) Freeze-drying:

[0069] Place the rolled tea in step (3) in a vacuum freeze-drying chamber for vacuum drying treatment, and then perform stem picking and packaging.

[0070] During the ultrasonic treatment described in operation a of step (1), the frequency of the ultrasonic wave is controlled at 40 kHz.

[0071] During the withering treatment described in operation a of step (1), wither until the moisture content of the fresh leaves is 80%.

[0072] During the cold plasma treatment described in operation b of step (1), the frequency is controlled at 9 MHz, the power is 120 W, and the gas flow rate is 240 mL / min.

[0073] During the microwave fixation described in step (2), the power of the microwave is controlled at 400 W.

[0074] During the vacuum drying treatment described in step (4), the vacuum degree is controlled at 3 Pa, the freezing temperature is -4°C, the freezing time is 12 min, the drying temperature is 60°C, and it is dried until the moisture content is 9%.

[0075] Comparative Example 1

[0076] Compared with Example 2, in the fresh leaf pretreatment of step (1) in this Comparative Example 1, the entire process of operation a is omitted, and the method steps other than this are the same.

[0077] Comparative Example 2

[0078] Compared with Example 2, in the fresh leaf pretreatment of step (1) in this Comparative Example 2, the entire process of operation b is omitted, and the method steps other than this are the same.

[0079] Comparative Example 3

[0080] Compared with Example 2, in this Comparative Example 3, the entire process of fresh leaf pretreatment in step (1) is omitted, and the method steps other than this are the same.

[0081] Comparative Example 4

[0082] Compared with Example 2, in this Comparative Example 4, the microwave killing green treatment in step (2) is replaced with a conventional killing green treatment, and the method steps other than this are the same.

[0083] Comparative Example 5

[0084] Compared with Example 2, in this Comparative Example 5, the vacuum freeze-drying in step (4) is replaced with constant temperature (60°C) drying, and the method steps other than this are the same.

[0085] Comparative Example 6

[0086] Compared with Example 2, in this Comparative Example 6, the microwave killing green treatment in step (2) is replaced with a conventional killing green treatment, and at the same time, the vacuum freeze-drying in step (4) is replaced with constant temperature (60°C) drying, and the method steps other than this are the same.

[0087] Control Group

[0088] The application number is: A method for killing green tea leaves disclosed in CN201810519694.8. Specifically refer to the method of Example 2 in the specific implementation part of this invention.

[0089] To compare the effects of this application, fresh leaves picked in the same batch were selected as the test objects. The picked fresh leaves were randomly divided into 8 equal-quality and equal-quantity portions, and then tea was prepared using the methods of Example 2, Comparative Examples 1-6, and the control group respectively. Then, the decomposition rates of bifenthrin, imidacloprid, and carbendazim were tested with reference to the standard of NY / T 761-2008 (specific test comparison data are as Figure 1 shown); the total number of colonies, the number of molds, and the number of Escherichia coli were detected with reference to the standard of GB 4789-2010 (specific test comparison data are shown in Table 1 below).

[0090] Table 1

[0091]

[0092]

[0093] Note: The total number of colonies in the fresh leaves is 2.3×10 4 cfu / g, the number of molds is 5.2×10 2 cfu / g, and the number of Escherichia coli is 1.5×10 3 cfu / g.

[0094] As can be seen from Table 1 above, this application provides a high-quality tea processing technology. By improving the tea processing technology, the invasion of microorganisms is effectively avoided, and molds, Escherichia coli, etc. existing in the fresh leaves have a good killing effect, thereby improving the quality of tea.

[0095] From Figure 1 it can be seen that this application provides a high-quality tea processing technology. Through this processing technology, the decomposition of bifenthrin, imidacloprid, and carbendazim can be promoted, thereby improving the quality of tea.

[0096] The above are only the preferred embodiments of the present invention, but the present invention is not limited to the described implementation scope. Any changes made according to the concept of the present invention, or equivalent implementation examples modified into equivalent changes, still within the spirit covered by the specification, shall be within the protection scope of the present invention.

Claims

1. A high-quality tea processing technology, characterized in that, It includes the following steps: (1) Pretreatment of fresh leaves: a. Place the fresh leaves in a bamboo utensil for withering, and conduct ultrasonic treatment during withering; b. Place the fresh leaves treated in operation a in a cold plasma device for cold plasma treatment, and take them out for standby after completion; (2) Microwave fixation: Place the fresh leaves pretreated in step (1) in a microwave fixation machine for microwave fixation treatment, and take out the tea leaves for standby after completion; (3) Rolling: Place the tea leaves treated by microwave fixation in step (2) in a rolling machine for rolling, and then carry out wrapping rolling and keep for standby; (4) Freeze-drying: Place the rolled tea leaves in step (3) in a vacuum freeze-drying box for vacuum drying treatment, and after completion, pick out the stems and package them.

2. The high-quality tea processing technology according to claim 1, wherein During the ultrasonic treatment described in operation a of step (1), control the frequency of the ultrasonic wave to be 30 - 40 kHz.

3. The high-quality tea processing technology according to claim 1, characterized in that, During the withering treatment described in operation a of step (1), wither until the moisture content of the fresh leaves is 70 - 80%.

4. The high-quality tea processing technology according to claim 1, characterized in that, During the cold plasma treatment described in operation b of step (1), control the frequency to be 8 - 9 MHz, the power to be 100 - 120 W, and the air flow rate to be 200 - 240 mL / min.

5. The high-quality tea processing technology according to claim 1 is characterized in that, During the microwave fixation described in step (2), control the power of the microwave to be 300 - 400 W.

6. The high-quality tea processing technology according to claim 1 is characterized in that, During the vacuum drying treatment described in step (4), control the vacuum degree to be 2 - 3 Pa, the freezing temperature to be -8 - -4 °C, the freezing time to be 8 - 12 min, the drying temperature to be 50 - 60 °C, and dry until the moisture content is 6 - 9%.

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