Jasmine Tea Processing Equipment and Method Based on Microwave Segmentation Technology

Abstract

This invention belongs to the field of jasmine tea processing technology, and discloses a jasmine tea processing equipment and method based on microwave segmented technology. The processing method involves mixing pre-treated green tea leaves and fresh jasmine flowers, followed by scenting under microwave conditions of varying power. Then, drying and pesticide residue degradation are performed in stages under different microwave conditions, specifically including three stages: microwave pre-degradation treatment, microwave main drying and degradation treatment, and microwave constant temperature shaping treatment. The equipment used includes a vibrating sieve, a hot air dryer, a tea leaf storage silo, an automatic screening machine, a fruit and vegetable washing machine, a fresh flower storage silo, a mixing tank, a microwave processing device, an air curtain cooling device, a sieving and grading device, a first conveyor belt, and a second conveyor belt. This invention achieves improved scenting efficiency, shortened drying cycle, and pesticide residue degradation through the organic combination of microwave scenting and microwave segmented drying.

Description

Technical Field

[0001] This invention belongs to the field of jasmine tea processing technology, specifically relating to a jasmine tea processing equipment and method based on microwave segmentation technology. Background Technology

[0002] Jasmine tea is typically made by scenting green tea with jasmine flowers using a traditional scenting process. It combines the refreshing aroma of green tea with the rich fragrance of jasmine, and also possesses the health benefits of both tea and jasmine, such as calming, beautifying the skin, clearing the liver and improving eyesight, clearing heat and detoxifying, antibacterial and anti-inflammatory properties, aiding digestion, and promoting weight loss and lowering cholesterol. The processing of jasmine tea mainly includes steps such as tea base preparation, fresh flower preservation, scenting, and drying. Scenting involves mixing and layering the prepared tea base with open jasmine flowers in a specific ratio. This allows the tea base to absorb moisture and aroma from the flowers, while the flowers generate heat through respiration. Therefore, the temperature inside the pile rises during scenting. To prevent the tea from deteriorating due to high temperatures, the pile needs to be turned over to dissipate heat (ventilation), ensuring the flowers continue to release their fragrance and the tea fully absorbs it. Currently, scenting still relies heavily on manual intervention, including ventilation, heat dissipation, and mixing. Furthermore, to obtain high-quality jasmine tea, multiple scenting processes (such as five, seven, or nine scentings) are often required, leading to low processing efficiency. Mechanical scenting often suffers from short contact time between the tea and flowers and insufficient absorption. Additionally, most jasmine teas are currently dried with hot air at 90-100℃. Prolonged high-temperature drying can easily degrade heat-sensitive flavor and nutrients in jasmine tea. Furthermore, both tea leaves and jasmine flowers may carry pesticide residues during jasmine tea production. In particular, the commonly used methods of washing jasmine flowers during fresh flower cultivation are inefficient and ineffective at degrading pesticides bound inside the cells. Subsequent scenting and drying processes also fail to effectively degrade and remove pesticide residues. Therefore, current jasmine tea processing techniques suffer from problems such as low scenting efficiency, drying affecting the nutritional components of the tea, and difficulty in degrading and removing pesticide residues. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention discloses a jasmine tea processing equipment and method based on microwave segmentation technology. By organically combining microwave scenting with microwave segmented drying, it achieves improved scenting efficiency, shortened drying cycle, and degradation of pesticide residues.

[0004] This invention is achieved using the following technical solution: A method for processing jasmine tea based on microwave segmentation technology includes the following steps: S1. Select roasted green tea, remove tea stems, fragments and impurities, and sieve to obtain tea base raw material. Dry the tea base raw material again at 60-70℃ for 15-20 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 4-6%. The re-drying reduces the moisture content in the tea base and makes the tea base form a loose and porous structure, which is conducive to the subsequent adsorption of floral fragrance. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water for 10-15 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment with a temperature of 22-25℃ and a relative humidity of 70-80% for 4-6 hours to obtain fresh flower material, which promotes the slow opening of the flowers and releases aroma precursor substances; S3. The tea base and fresh flower material are evenly mixed to obtain a mixture. The mixture is then subjected to high-power microwave treatment. The microwave power is 100-150W, the temperature is controlled at 30-33℃, and the treatment time is 2-3 hours. In this way, through the gentle thermal effect and molecular vibration of microwaves, the transformation of jasmine aroma precursors is accelerated, promoting the slow release of rich aroma from the fresh flowers, while avoiding the volatilization of aroma caused by high temperature. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave power in the low-power microwave treatment is 80-120 W, and the temperature is controlled at 28-30℃. The treatment time is 3-4 hours. This maintains the best adsorption environment for tea leaves and fresh flowers. The microwave vibration makes the pores of the tea leaves fully open, enhances the adsorption efficiency of tea fragrance on jasmine fragrance, and at the same time inhibits local heating in the scenting pile, replacing the traditional artificial ventilation and heat dissipation. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. In the microwave pre-degradation treatment, the microwave power is 300-400W, the temperature is controlled at 45-50℃, and the treatment time is 3-5min. The raw materials are preheated by microwave action to reduce the temperature difference in subsequent drying and to initially break the chemical bonds of pesticide molecules. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. In the microwave drying degradation treatment, the microwave power is 500-600W, the temperature is controlled at 55-60℃, and the treatment time is 5-8min. In this way, while rapidly evaporating and removing moisture, the microwave can also improve the degradation effect of residual pesticides. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 200-300W, the temperature is controlled at 50-55℃, and the treatment time is 3-5min. This stabilizes the moisture content in the jasmine tea and avoids high temperature damage to the flavor components. S8. The scenting material processed in step S7 is quickly cooled to room temperature to prevent residual heat from causing the tea to deteriorate or lose its aroma. After cooling, it is sieved to obtain the finished jasmine tea.

[0005] Furthermore, in step S2, the temperature of the clean water does not exceed 30°C.

[0006] Furthermore, in step S3, the weight ratio of the tea base to the fresh flower material is (4-6):1.

[0007] Furthermore, the microwave processing in steps S3 and S4 uses microwaves with a frequency not exceeding 1000MHz and operates in an intermittent mode, that is, the microwave operates for 1 minute and then pauses for 2 minutes.

[0008] Furthermore, the microwave processing in steps S5, S6 and S7 all uses microwaves with a frequency of 2450MHz.

[0009] Furthermore, in step S8, the scented material treated in step S7 is cooled to 20-25°C at a rate of 1-3°C / min.

[0010] A jasmine tea processing device based on microwave segmentation technology includes the following apparatus: Vibrating screen: Used to remove tea stems, broken pieces and impurities from green tea, and to send the screened green tea to a hot air dryer for further processing; Hot air dryer: used to dry green tea to obtain tea blanks, and the cooled tea blanks are sent to the tea blank storage silo for storage; Automatic sorting machine: used to remove sepals, stems, broken flowers and moldy individuals from fresh jasmine flowers, and send the sorted fresh jasmine flowers to a fruit and vegetable washing machine for further processing; Fruit and vegetable washing machine: used for washing fresh jasmine flowers with clean water; Fresh flower storage bin: Used for fresh flower materials. After being cleaned by a fruit and vegetable washing machine, fresh jasmine flowers are sent to a cultivation room to promote flowering, and then sent to the fresh flower storage bin for preservation. Mixing tank: Used to receive tea leaves from the tea leaf storage bin and fresh flower material from the fresh flower storage bin, and to mix them evenly; Microwave processing device: used to microwave process materials, and the microwave processing device is divided into five regions, each region is provided with one or more microwave feed ports for feeding microwaves into the corresponding region; Air curtain cooling device: used to cool materials that have been treated with microwaves; Screening and grading device: used to screen materials of different particle sizes; The discharge port of the mixing tank and the microwave processing device are connected by a first conveyor belt, and a second conveyor belt is provided in each area of ​​the microwave processing device.

[0011] Furthermore, the thickness of the material on the first and second conveyor belts is 3 to 5 cm; the speed of the first and second conveyor belts is 0.5 to 1 m / min.

[0012] Furthermore, each area of ​​the microwave device is equipped with a temperature detection device at its entrance. When the entrance temperature of a certain area exceeds the lower limit of the operating temperature of that area, the conveyor belt speed is increased. For every 3°C increase, the processing time of that area is shortened by 10 to 15 seconds.

[0013] Compared with existing technologies, this technical solution has the following advantages: 1. In the scenting stage, this invention employs a phased microwave treatment. The gentle thermal effect of microwaves precisely controls the scenting environment temperature, replacing traditional manual temperature control and avoiding the problems of high-temperature burning of the flowers and low-temperature adsorption efficiency. The molecular vibration effect of microwaves loosens the adhesion between tea particles, increasing the contact area between the tea and fresh flowers, while simultaneously opening the internal pores of the tea, improving the adsorption capacity and uniformity of the floral aroma. The combination of intermittent stirring conveyor belt and segmented power control eliminates the need for manual ventilation and heat dissipation, achieving automation and continuity in the scenting process. In the microwave drying stage, the microwaves used have strong penetrating power, directly acting on the water molecules inside the tea leaves, causing them to vibrate, heat up, and evaporate rapidly. Compared to traditional hot air drying, the drying efficiency is significantly improved. Moreover, the segmented gradient power design ensures rapid moisture removal while avoiding the damage to heat-sensitive components such as tea polyphenols and amino acids caused by single high temperatures, achieving synergy between drying and quality preservation. In addition, the thermal effect of microwaves can kill more than 90% of bacteria, mold, and insect eggs on the surface of the tea leaves, extending the product's shelf life.

[0014] 2. This invention can significantly shorten the scenting time of jasmine tea and improve the scenting efficiency. At the same time, it can effectively degrade pesticide components such as acetamiprid and chlorpyrifos residues in jasmine flowers. Compared with traditional drying methods, it can not only avoid the pyrolysis of heat-sensitive components and ensure the quality of tea, but also quickly degrade pesticide residues inside the tea. Furthermore, with appropriate equipment, it can achieve continuous operation and meet the requirements of automated and large-scale production. Attached Figure Description

[0015] Figure 1 This is a connection diagram of the device described in Example 1.

[0016] Figure 2 This is a statistical chart showing the detection of acetamiprid and imidacloprid content in jasmine tea after treatment under different microwave and temperature conditions in Experiment Example 1. CK represents the control group, and W1 to W4 represent Examples 2 to 5.

[0017] Figure 3This is a statistical chart showing the detection of acetamiprid and imidacloprid content in jasmine tea obtained after different treatment methods in Experiment Example 2. CK represents the control group, and W1 to W4 represent Examples 2 to 5.

[0018] Figure 4 This is a statistical chart showing the detection of nutrient content in jasmine tea obtained after different treatment methods in Experiment Example 2, where 1 to 4 represent Examples 2 to 5.

[0019] Reference numerals: 1-Vibrating screen, 2-Hot air dryer, 3-Tea blank storage bin, 4-Automatic screening machine, 5-Fruit and vegetable washing machine, 6-Fresh flower storage bin, 7-Mixing tank, 8-Microwave processing device, 9-Air curtain cooling device, 10-Screening and grading device, 11-First conveyor belt, 12-Second conveyor belt. Detailed Implementation

[0020] The present invention is further illustrated by the following examples, but these are not intended to limit the invention. Specific experimental conditions and methods not specified in the following examples are generally conventional methods well known to those skilled in the art.

[0021] Example 1: A jasmine tea processing device based on microwave segmentation technology, such as... Figure 1 As shown, it includes the following devices: Vibrating screen 1: Used to remove tea stems, broken pieces and impurities from green tea, and send the screened green tea to hot air dryer 2 for further processing; Hot air dryer 2: used to dry green tea to obtain tea blanks. The cooled tea blanks are sent to tea blank storage bin 3 for storage. Automatic sorting machine 4: Used to remove calyxes, stems, damaged flowers and moldy individuals from fresh jasmine flowers, and send the sorted fresh jasmine flowers to fruit and vegetable washing machine 5 for processing; Fruit and vegetable washing machine 5: Used for washing fresh jasmine flowers with clean water; Fresh flower storage bin 6: Used for fresh flower materials. After being cleaned by the fruit and vegetable washing machine 5, the fresh jasmine flowers are sent to the cultivation room to promote flowering, and then sent to the fresh flower storage bin 6 for storage. Mixing tank 7: Used to receive tea leaves from tea leaf storage bin 3 and fresh flower material from fresh flower storage bin 6, and to mix them evenly; Microwave processing device 8: used to microwave process materials, and the microwave processing device 8 is divided into five regions, each region is provided with one or more microwave feed ports for feeding microwaves into the corresponding region; Air curtain cooling device 9: Used to cool materials that have undergone microwave treatment; Screening and grading device 10: used for screening materials of different particle sizes; The discharge port of the mixing tank 7 and the microwave processing device 8 are connected by a first conveyor belt 11. Each area of ​​the microwave processing device 8 is provided with a second conveyor belt 12. Each area of ​​the microwave device 8 is equipped with a temperature detection device at its entrance. When the entrance temperature of a certain area exceeds the lower limit of the operating temperature of that area, the speed of the conveyor belt is increased. For every 3°C increase, the processing time of that area is shortened by 10 to 15 seconds.

[0022] Example 2: A jasmine tea processing method based on microwave segmentation technology, which uses the equipment described in Example 1, specifically includes the following steps: S1. Select roasted green tea, remove tea stems, fragments, and impurities, and sieve to obtain tea base material. Dry the tea base material again at 65℃ for 18 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 5%. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water at 23℃ for 12 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment with a temperature of 23℃ and a relative humidity of 75% for 5 hours to obtain fresh flower material. S3. The tea base and fresh flower material are evenly mixed to obtain a mixture. The weight ratio of the tea base to the fresh flower material is 5:1. The thickness of the mixture on the conveyor belt is 4cm. The speed control range of the conveyor belt is 0.5~1m / min. The mixture is first subjected to high-power microwave treatment. The frequency of the microwave in the high-power microwave treatment is 945MHz, the power is 120W, the intermittent working mode is adopted, the microwave works for 1 minute and then pauses for 2 minutes, and the temperature is controlled at 32℃. The treatment time is 2.5 hours. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave frequency in the low-power microwave treatment is 945MHz, the power is 100W, the intermittent operation mode is adopted, the microwave is paused for 2 minutes after 1 minute of operation, and the temperature is controlled at 29℃. The treatment time is 3.5h. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. The microwave power in the microwave pre-degradation treatment is 350W, the frequency is 2450MHz, the temperature is controlled at 46℃, and the treatment time is 4min. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. The microwave power in the microwave drying degradation treatment is 550W, the frequency is 2450MHz, the temperature is controlled at 56℃, and the treatment time is 6min. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 250W, the frequency is 2450MHz, the temperature is controlled at 52℃, and the treatment time is 4.5min. S8. The scenting material processed in step S7 is cooled to 23°C at a rate of 2°C / min, and then sieved to obtain the finished jasmine tea.

[0023] Example 3: A jasmine tea processing method based on microwave segmentation technology, which uses the equipment described in Example 1, specifically includes the following steps: S1. Select roasted green tea, remove tea stems, fragments, and impurities, and sieve to obtain tea base material. Dry the tea base material again at 60℃ for 20 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 4%. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water at 20℃ for 10 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment with a temperature of 22℃ and a relative humidity of 70% for 4 hours to obtain fresh flower material. S3. The tea base and fresh flower material are evenly mixed to obtain a mixture. The weight ratio of the tea base to the fresh flower material is 4:1. The thickness of the mixture on the conveyor belt is 3cm. The speed of the conveyor belt is controlled within the range of 0.5 to 1m / min. The mixture is first subjected to high-power microwave treatment. The frequency of the microwave in the high-power microwave treatment is 945MHz, the power is 100 to 150W, and the intermittent working mode is adopted. After microwave working for 1 minute, it is paused for 2 minutes. The temperature is controlled at 30℃, and the treatment time is 3h. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave frequency in the low-power microwave treatment is 945MHz, the power is 80W, the intermittent working mode is adopted, the microwave is paused for 2 minutes after working for 1 minute, and the temperature is controlled at 28℃. The treatment time is 4 hours. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. The microwave power in the microwave pre-degradation treatment is 300W, the frequency is 2450MHz, the temperature is controlled at 45℃, and the treatment time is 5min. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. The microwave power in the microwave drying degradation treatment is 500W, the frequency is 2450MHz, the temperature is controlled at 55℃, and the treatment time is 8min. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 200W, the frequency is 2450MHz, the temperature is controlled at 50℃, and the treatment time is 5min. S8. The scenting material processed in step S7 is cooled to 25°C at a rate of 1°C / min, and then sieved to obtain the finished jasmine tea.

[0024] Example 4: A jasmine tea processing method based on microwave segmentation technology, which uses the equipment described in Example 1, specifically includes the following steps: S1. Select roasted green tea, remove tea stems, fragments, and impurities, and sieve to obtain tea base material. Dry the tea base material again at 68℃ for 16 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 4.5%. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water at 23℃ for 12 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment at 23℃ and 78% relative humidity for 5 hours to obtain fresh flower material. S3. The tea base and fresh flower material are evenly mixed to obtain a mixture. The weight ratio of the tea base to the fresh flower material is 5.5:1. The thickness of the mixture on the conveyor belt is 4cm. The speed control range of the conveyor belt is 0.5~1m / min. The mixture is first subjected to high-power microwave treatment. The frequency of the microwave in the high-power microwave treatment is 945MHz, the power is 120W, the intermittent working mode is adopted, the microwave works for 1 minute and then pauses for 2 minutes, and the temperature is controlled at 32℃. The treatment time is 2.5h. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave frequency in the low-power microwave treatment is 945MHz, the power is 100W, the intermittent operation mode is adopted, the microwave is paused for 2 minutes after 1 minute of operation, and the temperature is controlled at 28℃. The treatment time is 3.5h. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. The microwave power in the microwave pre-degradation treatment is 350W, the frequency is 2450MHz, the temperature is controlled at 48℃, and the treatment time is 3.5min. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. The microwave power in the microwave drying degradation treatment is 550W, the frequency is 2450MHz, the temperature is controlled at 59℃, and the treatment time is 7min. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 250W, the frequency is 2450MHz, the temperature is controlled at 53℃, and the treatment time is 4.5min. S8. The scenting material processed in step S7 is cooled to 20-25°C at a rate of 1-3°C / min. After cooling, it is sieved to obtain the finished jasmine tea.

[0025] Example 5: A jasmine tea processing method based on microwave segmentation technology, which uses the equipment described in Example 1, specifically includes the following steps: S1. Select roasted green tea, remove tea stems, fragments, and impurities, and sieve to obtain tea base material. Dry the tea base material again at 70℃ for 15 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 6%. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water at 25℃ for 15 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment with a temperature of 25℃ and a relative humidity of 80% for 6 hours to obtain fresh flower material. S3. The tea base and fresh flower material are evenly mixed to obtain a mixture. The weight ratio of the tea base to the fresh flower material is 6:1. The thickness of the mixture on the conveyor belt is 5cm. The speed control range of the conveyor belt is 0.5~1m / min. The mixture is first subjected to high-power microwave treatment. The frequency of the microwave in the high-power microwave treatment is 945MHz, the power is 150W, the intermittent working mode is adopted, the microwave works for 1 minute and then pauses for 2 minutes, and the temperature is controlled at 33℃. The treatment time is 2h. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave frequency in the low-power microwave treatment is 945MHz, the power is 120W, the intermittent working mode is adopted, the microwave is paused for 2 minutes after working for 1 minute, and the temperature is controlled at 30℃. The treatment time is 3 hours. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. The microwave power in the microwave pre-degradation treatment is 400W, the frequency is 2450MHz, the temperature is controlled at 50℃, and the treatment time is 3min. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. The microwave power in the microwave drying degradation treatment is 600W, the frequency is 2450MHz, the temperature is controlled at 60℃, and the treatment time is 5min. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 300W, the frequency is 2450MHz, the temperature is controlled at 50℃, and the treatment time is 4min. S8. The scenting material processed in step S7 is cooled to 25°C at a rate of 3°C / min, and then sieved to obtain the finished jasmine tea.

[0026] Experimental Example 1: Following the method described in Example 2, in step S6, different power microwaves or different temperatures were used for treatment. Fresh jasmine flowers that had undergone treatment were used as a control (CK). The degradation rates of acetamiprid and chlorpyrifos in the resulting jasmine tea were measured. Specific results are shown in [link to experimental example]. Figure 2 .

[0027] Depend on Figure 2 As the data shows, the present invention can achieve good pesticide residue degradation within the power and temperature range, and by controlling the temperature to avoid damaging the heat-sensitive components in jasmine tea, it can also control energy consumption.

[0028] Experimental Example 2: Jasmine tea was produced according to the methods described in Examples 2-5, and freshly bloomed jasmine flowers after treatment were used as a control. The moisture content, acetamiprid, and chlorpyrifos content of the product were tested. Specific test results are shown below. Figure 3 Simultaneously, the contents of tea water extract, tea polysaccharides, tea polyphenols, amino acids, catechins, and caffeine in jasmine tea were detected. Specific results can be found in [link to results]. Figure 4 .

[0029] Depend on Figure 3 and Figure 4 As can be seen from the data, the method described in this invention can avoid the destruction and loss of nutrients in jasmine tea. In particular, by adjusting the processing time of the microwave constant temperature shaping process according to the material temperature in the microwave main drying degradation process (Examples 2-4), the nutrients in jasmine tea can be better protected.

[0030] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for processing jasmine tea based on microwave segmentation technology, characterized in that: Includes the following steps: S1. Select roasted green tea, remove tea stems, fragments, and impurities, and sieve to obtain tea base material. Dry the tea base material again at 60-70℃ for 15-20 minutes, and then cool it to room temperature to obtain tea base. The moisture content of the tea base is 4-6%. S2. Take mature jasmine flowers with unopened corollas, remove the calyx, stems, damaged flowers and moldy individuals, rinse with clean water for 10-15 seconds, drain the surface water, spread evenly on a clean flower spreading rack, and then pre-spread in an environment with a temperature of 22-25℃ and a relative humidity of 70-80% for 4-6 hours to obtain fresh flower material. S3. Mix the tea base and fresh flower material evenly to obtain a mixture. Take the mixture and subject it to high-power microwave treatment. The power of the microwave in the high-power microwave treatment is 100-150W, the temperature is controlled at 30-33℃, and the treatment time is 2-3h. S4. The mixture processed in step S3 is subjected to low-power microwave treatment. The microwave power in the low-power microwave treatment is 80-120W, the temperature is controlled at 28-30℃, and the treatment time is 3-4h. S5. After the mixture processed in step S4 is screened to remove residual flower residue and fine tea dust, the scenting material is obtained. The scenting material is then subjected to microwave pre-degradation treatment. The microwave power in the microwave pre-degradation treatment is 300-400W, the temperature is controlled at 45-50℃, and the treatment time is 3-5min. S6. The scented material treated in step S5 is subjected to microwave drying degradation treatment. The microwave power in the microwave drying degradation treatment is 500-600W, the temperature is controlled at 55-60℃, and the treatment time is 5-8min. S7. The scented material processed in step S6 is subjected to microwave constant temperature shaping treatment. The microwave power in the microwave constant temperature shaping treatment is 200-300W, the temperature is controlled at 50-55℃, and the treatment time is 3-5min. S8. The scented material processed in step S7 is rapidly cooled to room temperature, and then sieved to obtain the finished jasmine tea.

2. The jasmine tea processing method based on microwave segmentation technology according to claim 1, characterized in that: Includes the following steps: In step S2, the temperature of the clean water should not exceed 30℃.

3. The jasmine tea processing method based on microwave segmentation technology according to claim 1, characterized in that: Includes the following steps: In step S3, the weight ratio of the tea base to the fresh flower material is (4-6):

1.

4. The jasmine tea processing method based on microwave segmentation technology according to claim 1, characterized in that: Includes the following steps: The microwave processing in steps S3 and S4 uses microwaves with a frequency not higher than 1000MHz and operates in an intermittent mode, that is, the microwave operates for 1 minute and then pauses for 2 minutes.

5. The jasmine tea processing method based on microwave segmentation technology according to claim 4, characterized in that: Includes the following steps: The microwave processing in steps S5, S6 and S7 all uses microwaves with a frequency of 2450MHz.

6. The jasmine tea processing method based on microwave segmentation technology according to claim 1, characterized in that: The process includes the following steps: In step S8, the scented material processed in step S7 is cooled to 20-25°C at a rate of 1-3°C / min.

7. A jasmine tea processing device based on microwave segmentation technology, applied to the method described in any one of claims 1 to 6, characterized in that: Includes the following devices: Vibrating screen (1): used to remove tea stems, broken pieces and impurities from green tea, and to send the screened green tea to a hot air dryer (2) for processing; Hot air dryer (2): used to dry green tea to obtain tea blanks. The cooled tea blanks are sent to the tea blank storage silo (3) for storage. Automatic sorting machine (4): used to remove calyxes, stems, broken flowers and moldy individuals from fresh jasmine flowers, and send the sorted fresh jasmine flowers to the fruit and vegetable washing machine (5) for processing; Fruit and vegetable washing machine (5): Used to wash fresh jasmine flowers with clean water; Fresh flower storage bin (6): Used for fresh flower materials. After the fresh jasmine flowers are cleaned by the fruit and vegetable washing machine (5), they are sent to the cultivation room to promote flowering, and then sent to the fresh flower storage bin (6) for preservation. Mixing tank (7): used to receive tea leaves from tea leaf storage bin (3) and fresh flower material from fresh flower storage bin (6) and mix them evenly; Microwave processing device (8): used to microwave process materials, and the microwave processing device (8) is divided into five regions, each region is provided with one or more microwave feed ports for feeding microwaves into the corresponding region; Air curtain cooling device (9): used to cool materials after microwave treatment; Screening and grading device (10): used to screen materials of different particle sizes; The discharge port of the mixing tank (7) and the microwave processing device (8) are connected by a first conveyor belt (11), and a second conveyor belt (12) is provided in each area of ​​the microwave processing device (8).

8. The jasmine tea processing equipment based on microwave segmentation technology according to claim 7, characterized in that: The thickness of the material on the first conveyor belt (11) and the second conveyor belt (12) is 3-5 cm; the speed of the first conveyor belt (11) and the second conveyor belt (12) is 0.5-1 m / min.

9. The jasmine tea processing equipment based on microwave segmentation technology according to claim 7, characterized in that: Temperature detection devices are provided at the entrance of each area in the microwave device (8). When the entrance temperature of a certain area exceeds the lower limit of the working temperature of that area, the speed of the conveyor belt is increased. For every 3°C increase, the processing time of that area is shortened by 10 to 15 seconds.

Images