Clean production process of jasmine tea

Abstract

The invention relates to the technical field of jasmine flower processing, and discloses a jasmine flower tea clean production process which comprises the following steps: S1, compound excitation pretreatment of jasmine flowers: performing ultrasonic treatment and ozone activation treatment on fresh jasmine flowers; s2, performing low-temperature dynamic multi-phase scenting: mixing the treated jasmine flowers with tea leaves, and performing multi-stage scenting by using a partitioned dynamic gas phase regulation and control system; s3, aroma trapping and re-injection: trapping non-adsorbed aroma components in the scenting tail gas through a molecular sieve adsorption and condensation recovery technology, and circularly injecting into the scenting chamber; s4, performing comprehensive drying on the tea leaves and the remaining flowers: performing a combined drying process of microwave drying, infrared drying and vacuum drying on the scented tea leaves; and carrying out water extraction and alcohol precipitation or fermentation conversion on the scented residual flowers. Through the synergistic effect of ultrasonic waves and ozone, the jasmine flower fragrance release efficiency is improved, microbial pollution is reduced, the adsorption efficiency of tea on aromatic molecules is improved, and fragrance waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of jasmine processing, in particular to a clean production process for jasmine tea. Background Art

[0002] Jasmine tea is a traditional and popular tea category, and its production core lies in the scenting process. However, due to technical limitations, the traditional scenting process has many shortcomings, which directly affect the aroma intensity, product consistency and production efficiency of jasmine tea. The defects of the existing technology are mainly reflected in the following aspects: In the prior art, jasmine pretreatment mostly relies on simple airing or washing, trying to improve the scenting effect by reducing moisture. However, this method is inadequate in terms of processing efficiency and aroma release. The cell wall of jasmine remains intact, and the aromatic molecules contained therein cannot be released quickly, especially in the early stage of scenting, and the aroma concentration is not ideal. What is more serious is that the effect of airing is greatly affected by external conditions such as humidity and temperature, and the treatment results fluctuate significantly. There are also deficiencies in microbial control, which can easily cause oxidation or deterioration of the flower materials, burying hidden dangers for the subsequent scenting process. Overall, the existing pretreatment methods are not only inefficient, but also limit the potential of jasmine aroma.

[0003] The existing scenting process usually uses a constant gas phase concentration method to release aroma. The entire process is not regulated in stages, and the changes in the adsorption rate of tea leaves are ignored. In the early stage of scenting, the concentration of aromatic molecules is low, resulting in low adsorption efficiency; in the later stage, when the tea leaves are close to saturation, a large number of aromatic molecules in the gas phase have nowhere to be adsorbed and are wasted. This mode of operation not only makes the utilization rate of aroma resources extremely low, but also easily causes the aroma intensity of the product to be unstable. At the same time, the traditional scenting tail gas is directly discharged, which dissipates a large number of precious aromatic molecules, which not only wastes resources, but also increases production costs and environmental burdens. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a clean production process for jasmine tea, which solves the problems of low aroma utilization, serious waste of resources, unstable product quality, etc. in the existing jasmine tea production process.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a clean production process of jasmine tea, comprising the following steps: S1. Composite excitation pretreatment of jasmine flowers: ultrasonic treatment and ozone activation treatment of fresh jasmine flowers; S2. Low-temperature dynamic multi-phase scenting: Mix the processed jasmine flowers with tea leaves and perform multi-stage scenting using a partitioned dynamic gas phase control system; S3, aroma capture and re-injection: the unabsorbed aroma components in the scenting tail gas are captured through molecular sieve adsorption and condensation recovery technology, and recycled into the scenting room; S4. Comprehensive drying of tea leaves and residual flowers: The tea leaves after scenting are dried by a combination of microwave drying, infrared drying and vacuum drying; the residual flowers after scenting are subjected to water extraction, alcohol precipitation or fermentation conversion.

[0006] Preferably, the ultrasonic frequency of the ultrasonic treatment of jasmine in step S1 is 20 to 50 kHz, the power density is 0.3 to 0.6 W / cm², and the treatment time is 5 to 10 minutes.

[0007] Preferably, the ozone concentration of the ozone activation treatment in step S1 is 5-10 ppm, the treatment time is 3-7 minutes, the ozone flow rate is 1-2 L / min, and the pressure is 0.05-0.1 MPa.

[0008] Preferably, in step S2, the temperature of the scenting is 30-40° C., the humidity is 60%-75%, and the gas phase flow rate is 0.5-1.0 m / s.

[0009] Preferably, the multi-stage scenting in step S2 includes: Initial enhancement stage: gas phase concentration is 2.0-3.0 mg / L, and the duration is 6-12 hours; Uniform diffusion stage: gas phase concentration is 1.5-2.0 mg / L, time is 8-16 hours; Adsorption enhancement stage: gas phase concentration is 1.0-1.5 mg / L, and the time is 4-8 hours.

[0010] Preferably, in step S3, the tail gas is captured by a molecular sieve adsorption device, the pore size of the molecular sieve is 0.3-0.5 nm, and the tail gas flow rate is 0.8-1.5 m / s.

[0011] Preferably, the condensation recovery in step S3 includes two-stage condensation: the primary condensation temperature is 30-40°C, and the deep condensation temperature is 5-10°C.

[0012] Preferably, in step S4, the microwave drying power of the tea leaves is 2-3 kW, the temperature is 40-50° C., and the time is 10-15 minutes.

[0013] Preferably, in step S4, the infrared drying temperature is 50-60° C., the time is 5-10 minutes, and the vacuum drying temperature is 40-50° C., the vacuum pressure is 0.02-0.05 MPa, and the time is 30-60 minutes.

[0014] Preferably, when the residual flowers are subjected to water extraction and alcohol precipitation treatment in step S4, the mass ratio of water to residual flowers is 1:10-1:15, the extraction temperature is 60° C., the extraction time is 1 hour, and the ethanol concentration of the alcohol precipitation is 70%-90%.

[0015] The present invention provides a clean production process for jasmine tea, which has the following beneficial effects: 1. The present invention adopts composite excitation pretreatment technology, and through ultrasonic cavitation and ozone gas synergistic treatment, significantly improves the release efficiency of jasmine fragrance components, and delays the oxidation and deterioration of flowers. Compared with the prior art that simply uses natural volatilization or a single pretreatment method, it solves the problems of insufficient release of fragrance components and low initial fragrance concentration.

[0016] 2. The present invention introduces a low-temperature dynamic multi-phase scenting process, adopts staged gas phase concentration control and multi-phase circulation release technology, and realizes efficient adsorption of jasmine fragrance. Compared with the problems of uneven gas phase release and low aroma utilization rate in the scenting process in the prior art, this process improves the adsorption efficiency of tea leaves for aromatic components, reduces aroma loss, and shortens the scenting time.

[0017] 3. The present invention significantly improves the utilization rate of tail gas resources through tail gas capture and re-injection technology combining molecular sieve adsorption with multi-stage condensation. Compared with the direct emission of aromatic components in tail gas in the prior art, this solution effectively reduces resource waste and reduces waste gas emissions, achieving higher environmental friendliness.

[0018] 4. The present invention adopts a combined drying process, and through the combined application of microwave, infrared and vacuum drying, it realizes low-temperature and efficient drying of tea leaves and full locking of their aroma. Compared with the traditional single high-temperature drying process, it solves the problems of aroma loss and unstable quality caused by high temperature, and significantly reduces energy consumption during the drying process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example: Please refer to the attached Figure 1 The embodiment of the present invention provides a clean production process for jasmine tea, comprising the following steps: S1. Composite excitation pretreatment of jasmine flowers: ultrasonic treatment and ozone activation treatment of fresh jasmine flowers; Jasmine Cleansing: Put freshly picked jasmine flowers into low-concentration ozone water (ozone concentration is 2-5ppm, water temperature is 20-25℃) for 2-5 minutes to remove surface impurities and microorganisms through the strong oxidizing effect of ozone.

[0022] Ultrasonic treatment: The cleaned jasmine flowers were soaked in deionized water, the ultrasonic frequency was set to 20-50kHz, the power density was 0.3-0.6W / cm², and the treatment time was 5-10 minutes.

[0023] Ozone Activation Treatment: During the ultrasonic treatment, low concentration ozone gas (5-10 ppm) is added simultaneously, the flow rate is 1-2 L / min, the pressure is controlled at 0.05-0.1 MPa, and the treatment time is 3-7 minutes.

[0024] S2. Low-temperature dynamic multi-phase scenting: Mix the processed jasmine flowers with tea leaves and perform multi-stage scenting using a partitioned dynamic gas phase control system; Use a closed multifunctional scenting room, equipped with a gas phase concentration monitoring system (detection range of 1.0-3.0 mg / L), a circulating air flow system, and a dynamic temperature and humidity control module. The temperature is controlled at 30-40°C, the humidity is 60%-75%, and the gas phase flow rate is 0.5-1.0 m / s.

[0025] Initial enhancement stage: Mix jasmine flowers and tea leaves in a certain proportion (1:3 to 1:5) and spread them in the scenting room with a flower layer thickness of 2 to 5 cm. The gas phase concentration is adjusted to 2.0 to 3.0 mg / L for 6 to 12 hours.

[0026] Uniform diffusion stage: adjust the air flow speed to 0.6-0.8 m / s, maintain the concentration at 1.5-2.0 mg / L, and control the humidity at 65%-70% for 8-16 hours.

[0027] Adsorption enhancement stage: The unabsorbed aromatic molecules are collected in a circular manner and the concentration is maintained at 1.0-1.5 mg / L through the gas re-injection device for 4-8 hours.

[0028] S3, aroma capture and re-injection: the unabsorbed aroma components in the scenting tail gas are captured through molecular sieve adsorption and condensation recovery technology, and recycled into the scenting room; The exhaust gas is treated by a molecular sieve adsorption device. The molecular sieve material is activated carbon fiber or zeolite (pore size range is 0.3~0.5nm), and the exhaust gas flow rate is controlled at 0.8~1.5m / s.

[0029] The tail gas is treated by a two-stage condensation device, with the primary condensation temperature at 30-40°C and the deep condensation temperature at 5-10°C, condensing the aromatic molecules into liquid.

[0030] The recovered liquid aromatic molecules are injected back into the scenting chamber in a ratio of 1:50 to 1:100, liquid:gas, through an atomizing injection device, forming a closed-loop circulation system.

[0031] S4. Comprehensive drying of tea leaves and residual flowers: The tea leaves after scenting are dried by a combination of microwave drying, infrared drying and vacuum drying; the residual flowers after scenting are subjected to water extraction, alcohol precipitation and fermentation transformation.

[0032] Tea drying: Microwave drying: initial dehydration, power range is 2-3kW, temperature is controlled at 40-50℃, time is 10-15 minutes.

[0033] Infrared drying: for aroma setting, the temperature is 50-60℃, and the time is 5-10 minutes.

[0034] Vacuum drying: final shaping, the temperature is controlled below 50°C, the vacuum pressure is 0.02-0.05MPa, and the time is 30-60 minutes.

[0035] Remaining flower treatment: Water extraction and alcohol precipitation: add the remaining flowers into water, and extract at 60℃ for 1 hour at a ratio of flower to water of 1:10-1:15; precipitate the extract with ethanol (concentration 70%-90%) to separate the aroma extract.

[0036] Fermentation conversion: Add the residue after extraction into yeast solution (concentration 10 6 ~10 7 CFU / mL), and ferment at 30-35°C for 48-72 hours to prepare organic fertilizer or biologically active materials.

[0037] Example 1: Composite excitation pretreatment of jasmine flowers Take fresh jasmine flowers and wash them in ozone water with an ozone concentration of 3ppm and a water temperature of 25℃ for 4 minutes. After washing, place the flowers in an ultrasonic device, inject deionized water, set the ultrasonic frequency to 30kHz, power density to 0.4W / cm², and treat for 8 minutes. At the same time, introduce ozone gas with a concentration of 8ppm, a flow rate of 1.5L / min, and a pressure of 0.08MPa.

[0038] Low temperature dynamic multiphase heating Jasmine flowers and tea leaves are mixed in a mass ratio of 1:4, with a flower layer thickness of 3cm. The mixture is placed in a closed scenting room, with a temperature of 35°C and a humidity of 70%. The scenting process is divided into three stages: In the initial stage, the gas phase concentration was maintained at 2.8 mg / L for 10 hours.

[0039] During the diffusion stage, the air flow velocity was adjusted to 0.7 m / s and the gas phase concentration was maintained at 1.8 mg / L for 14 h.

[0040] During the adsorption stage, the tail gas was collected and re-injected in a circular manner, and the gas phase concentration was set to 1.2 mg / L for 6 hours.

[0041] Aroma capture and reinjection The tail gas is treated with molecular sieves with a pore size of 0.4nm and the tail gas flow rate is controlled at 1.2m / s. The primary condensation temperature of the condensation device is 40℃ and the deep condensation is 8℃. The recovered aromatic liquid is atomized at a ratio of 1:80 and then re-injected into the scenting room.

[0042] Drying of tea leaves and residual flowers The tea leaves after scenting are dried by microwave at a power of 2.5kW, a temperature of 45°C, and a time of 12 minutes. Then infrared drying is performed at a temperature of 55°C and a time of 8 minutes. Finally, vacuum drying is performed at a temperature below 48°C, a vacuum pressure of 0.03MPa, and a time of 50 minutes. The remaining flowers after scenting are extracted with water at a ratio of 1:12, at an extraction temperature of 60°C, for 1 hour, and then the extract is precipitated with 75% ethanol.

[0043] Embodiment 2: Composite excitation pretreatment of jasmine flowers The jasmine flowers were washed in ozone water (ozone concentration 2ppm, soaked for 3 minutes), treated with 20kHz ultrasonic wave, power density 0.35W / cm², time 10 minutes. Then 5ppm ozone gas was introduced, pressure controlled at 0.1MPa, and treated for 6 minutes.

[0044] Low temperature dynamic multiphase heating Mix jasmine flowers and tea leaves in a ratio of 1:5, with a flower layer thickness of 4cm, a scenting temperature of 30℃ and a humidity of 65%. The process is divided into three stages: In the initial high concentration stage, the gas phase concentration was 3.0 mg / L and the duration was 6 hours.

[0045] In the mid-term stable diffusion stage, the gas phase concentration was 2.0 mg / L, the air flow velocity was 0.6 m / s, and the time was 12 hours.

[0046] In the recycling stage, the tail gas is recovered and injected at a concentration of 1.5 mg / L for 8 hours.

[0047] Aroma capture and recirculation The tail gas is adsorbed by molecular sieve (pore size 0.5nm), the tail gas flow rate is 0.9m / s, and the condensation temperature is set to 35℃ (primary) and 5℃ (deep condensation). The collected liquid aromatic substances are diluted to a ratio of 1:100 and then atomized and sprayed into the scenting room, and the cycle is repeated 4 times.

[0048] Drying and by-product handling The tea leaves were dried by microwave at 3kW, 48°C, and 10 minutes, followed by infrared drying (57°C, 7 minutes), and finally vacuum drying (below 50°C, 0.02MPa, 60 minutes). The remaining flowers were extracted by water (ratio 1:10, extraction temperature 65°C, 40 minutes), and then fermented to prepare organic fertilizer.

[0049] Embodiment 3: Composite excitation pretreatment of jasmine flowers Jasmine flowers were washed with 4ppm ozone water at 20℃ for 5 minutes. Then they were placed in an ultrasonic treatment apparatus at 25kHz, 0.5W / cm², and 7 minutes. 7ppm ozone gas was introduced at a flow rate of 1.8L / min and a pressure of 0.09MPa for 5 minutes.

[0050] Low temperature dynamic multiphase heating Mix jasmine flowers and tea leaves in a mass ratio of 1:3, and spread them in a thickness of 3cm. The temperature is controlled at 32℃, the humidity is 70%, and the scenting time is 36 hours: In the initial stage, the gas phase concentration was 2.5 mg / L and the time was 8 hours.

[0051] In the diffusion stage, the gas phase concentration was 1.8 mg / L, the time was 16 hours, and the air flow velocity was 0.8 m / s.

[0052] In the strengthening stage, the concentration after aroma recovery is 1.0 mg / L, and the time is 12 hours.

[0053] Aroma capture and recycling The tail gas is treated by a molecular sieve adsorption device (pore size 0.4nm), with a tail gas flow rate of 1.0m / s. The primary condensation temperature is 40℃, and the deep condensation is 10℃. The recovered aromatic components are sprayed and atomized into the scenting chamber at a ratio of 1:70, and the cycle is continued for 6 times.

[0054] Drying process Microwave drying (power 3kW, temperature 50℃, time 10 minutes); infrared drying (temperature 60℃, time 8 minutes); vacuum drying (temperature below 50℃, vacuum pressure 0.03MPa, time 45 minutes).

[0055] Embodiment 4: Composite excitation pretreatment of jasmine flowers Take fresh jasmine flowers, wash them with ozone water (concentration 3ppm, time 4 minutes), treat them with 25kHz ultrasonic wave, power density 0.45W / cm², time 8 minutes, and introduce 6ppm ozone gas for 6 minutes.

[0056] Scenting process Jasmine flowers and tea leaves are mixed in a ratio of 1:4, scenting temperature is 35℃, humidity is 65%, flower layer thickness is 3cm, time is 28 hours: In the initial stage, the gas phase concentration was 2.6 mg / L and the time was 10 hours.

[0057] Diffusion stage, concentration 1.8 mg / L, time 14 hours.

[0058] In the circulation stage, the tail gas is recovered and then injected at a concentration of 1.3 mg / L for 4 hours.

[0059] Aroma recovery and reuse The tail gas was adsorbed by molecular sieve (pore size 0.3nm), the flow rate was 1.1m / s, and the condensation temperature was 35℃ and 8℃. The recovered aromatic liquid was injected into the scenting chamber at a ratio of 1:90 and circulated for 5 times.

[0060] Residual flower treatment The remaining flowers after scenting are added with water in a ratio of 1:12 for extraction at a temperature of 60°C for 1 hour, and the extract is precipitated with 80% ethanol to separate the jasmine essential oil. The residue after extraction is fermented at a temperature of 32°C for 72 hours to produce a functional fertilizer.

[0061] Embodiment 5: Pretreatment of Jasmine Jasmine flowers were soaked in water with an ozone concentration of 2ppm for 3 minutes, rinsed with deionized water, and then treated with 20kHz ultrasonic waves at a power of 0.3W / cm² for 10 minutes. 8ppm ozone gas was introduced at a pressure of 0.08MPa for 6 minutes.

[0062] Scenting Jasmine and tea leaves were mixed in a ratio of 1:5, with a scenting temperature of 30°C and a humidity of 70%. The initial gas phase concentration was 3.0 mg / L, and the time was 8 hours; the gas phase concentration in the diffusion stage was 1.7 mg / L, and the time was 16 hours; the tail gas recovery injection concentration was 1.2 mg / L, and the time was 6 hours.

[0063] Drying and recycling Microwave power is 2.8kW, drying temperature is 45℃, time is 12 minutes; infrared drying temperature is 58℃, time is 7 minutes; vacuum drying temperature is below 50℃, pressure is 0.03MPa, time is 55 minutes. The aromatic components of tail gas are condensed and recovered for the preparation of essential oil.

[0064] Comparative Example 1: Preparation process: Jasmine flower pretreatment: Fresh jasmine flowers were dried under natural conditions for 2 hours to remove surface moisture and some impurities, and then washed with ozone-free water and subjected to ultrasonic treatment.

[0065] Low-temperature dynamic multiphase scenting: Jasmine flowers that have not been treated with composite excitation were mixed with tea leaves in a ratio of 1:4. The scenting conditions were kept consistent with those in Example 1, with a temperature of 35° C., a humidity of 70%, a scenting time of 28 hours, and the same staged gas phase concentration control.

[0066] Tail gas treatment: The tail gas is recovered by simple condensation without molecular sieve adsorption treatment. The condensation temperature is only set at 20°C without deep condensation.

[0067] Drying process: The tea drying process in Example 1 was followed, but the remaining flowers were not subjected to water extraction and alcohol precipitation treatment and were simply discarded directly.

[0068] Comparative Example 2: Preparation process: Jasmine flower pretreatment: The ultrasonic and ozone treatment method of Example 2 was used, with an ultrasonic frequency of 25 kHz, an ozone concentration of 5 ppm, and a treatment time of 10 minutes.

[0069] Low-temperature dynamic multi-phase scenting: jasmine flowers and tea leaves are mixed in a ratio of 1:5, the flower layer thickness is 4cm, the scenting temperature is 30℃, and the humidity is 65%. The scenting time is 28 hours, and the gas phase concentration and airflow speed are adjusted in three stages (initial concentration 3.0mg / L, mid-term 2.0mg / L, and late stage 1.5mg / L).

[0070] Tail gas treatment: The tail gas is discharged directly without molecular sieve adsorption and condensation recovery, and is not recycled.

[0071] Drying and residual flower treatment: Completed according to the drying and water extraction and alcohol precipitation method in Example 2.

[0072] Comparative Example 3: Preparation process: Jasmine pretreatment: The pretreatment method of Example 3 was used, with an ozone concentration of 4 ppm, an ultrasonic frequency of 30 kHz, a power density of 0.45 W / cm², and a treatment time of 8 minutes.

[0073] Scenting process: Jasmine flowers and tea leaves are mixed in a ratio of 1:3, the temperature is 32°C, and the humidity is 70%. The gas phase concentration is set to a single value of 2.5 mg / L, the scenting time is 28 hours, and there is no stage-by-stage dynamic control of the gas phase concentration and flow rate.

[0074] Tail gas treatment and recycling: Molecular sieve adsorption device (pore size 0.4nm) is used, the primary condensation temperature is 40℃, the deep condensation temperature is 8℃, and the gas is recycled and injected at a ratio of 1:70.

[0075] Drying: Same as Example 3.

[0076] Comparative Example 4: Preparation process: Jasmine pretreatment: The composite excitation treatment method of Example 4 was used, with an ozone concentration of 3 ppm, an ultrasonic frequency of 25 kHz, a power density of 0.4 W / cm², and a treatment time of 7 minutes.

[0077] Scenting process: jasmine flowers and tea leaves are mixed in a ratio of 1:4, the flower layer thickness is 3cm, the scenting temperature is 35℃, the humidity is 65%, and the scenting time is 28 hours. The gas phase concentration is regulated in stages (initial 2.6mg / L, mid-term 1.8mg / L, and 1.3mg / L after tail gas recovery).

[0078] Tail gas capture and recycling: Molecular sieve adsorption and two-stage condensation technology (pore size 0.3nm, condensation temperature 35℃ and 8℃) are used, and the recycling ratio is 1:90.

[0079] Drying: Only traditional high-temperature hot air drying is used, the temperature is 80℃, the time is 60 minutes, and there is no microwave, infrared and vacuum drying steps.

[0080] Comparative Example 5: Preparation process: Jasmine pretreatment: The composite excitation pretreatment process of Example 5 was adopted, with an ozone concentration of 2 ppm, an ultrasonic frequency of 20 kHz, a power density of 0.3 W / cm², and a treatment time of 10 minutes.

[0081] Scenting process: Jasmine and tea are mixed in a ratio of 1:5, the scenting temperature is 30°C, the humidity is not controlled, and it changes naturally with the indoor conditions (humidity range is 50%-80%). The scenting time is 28 hours, the initial gas phase concentration is 3.0mg / L, and the gas phase concentration in the diffusion stage is 1.7mg / L. No tail gas recovery injection and concentration precise control are performed.

[0082] Tail gas treatment: Tail gas is discharged directly without molecular sieve adsorption and condensation recovery equipment.

[0083] Drying process: A combination of microwave drying and infrared drying (microwave power 2.5 kW, temperature 45°C, time 12 minutes; infrared temperature 55°C, time 8 minutes) is used, without a vacuum drying step.

[0084] Experimental Example 1: Effect of jasmine compound stimulation treatment on aroma release Experimental Description Purpose Verify the effect of ozone and ultrasound synergistic treatment technology on the release of the main aromatic molecules of jasmine.

[0085] Experimental materials and equipment Fresh jasmine flowers, deionized water, ozone generator, ultrasonic treatment device, gas chromatography-mass spectrometry (GC-MS).

[0086] Analytical standard substances: linalool, phenylethyl alcohol, methyl benzoate.

[0087] Experimental procedures Sample processing Example 1 Sample: Take 50 grams of fresh jasmine flowers and soak them in deionized water with an ozone concentration of 3 ppm for 4 minutes at a water temperature of 25° C. Then, place the treated jasmine flowers in an ultrasonic treatment device, set the ultrasonic frequency to 30 kHz, the power density to 0.4 W / cm², and treat for 8 minutes.

[0088] Comparative Example 1 Sample: Take 50 grams of fresh jasmine flowers and dry them naturally in the air at a temperature of 25° C. for 2 hours without any additional treatment.

[0089] Balance of volatile aromatic components After the sample processing was completed, the jasmine flowers were placed in a sealed container for 30 minutes to ensure that the volatile aromatic components reached equilibrium.

[0090] Fragrance component testing GC-MS was used to analyze the main aromatic components (linalool, phenylethyl alcohol, methyl benzoate, etc.) in each group of jasmine flowers. Each group of samples was measured three times, and the peak areas were recorded and the average values ​​were calculated.

[0091] Table name: Effects of different pretreatment methods on the release of main aromatic components of jasmine Experimental Summary After jasmine flowers were treated with ozone and ultrasound, the release of aromatic molecules increased significantly. GC-MS data showed that the content of linalool and phenylethanol after the composite treatment was much higher than that of the naturally air-dried samples. The oxidative effect of ozone accelerated the metabolism of jasmine cells, while the cavitation effect of ultrasound destroyed the cell wall structure. This combination of physical and chemical effects directly promoted the release of endogenous aromatic molecules. In contrast, the natural air-drying method had a weak stimulation on cells and the release amount was low.

[0092] In the experimental data, the content of the main aromatic molecules in the composite treatment samples fluctuated slightly, indicating the stability of the treatment effect. In contrast, the release of aromatic molecules in the naturally air-dried samples was not only low, but also varied greatly, showing its uncertainty in the process. The drying conditions were significantly affected by the environment, while the composite treatment technology controlled the release rate and directionality through an external energy field, making the release of aromatic molecules more efficient and controllable.

[0093] Experimental Example 2: Effect of Dynamic Multiphase Scenting on the Adsorption Effect of Tea Experimental Description Purpose Verify the effect of dynamic multiphase staged gas phase concentration control on the adsorption of jasmine main aromatic molecules by tea.

[0094] Experimental materials and equipment Jasmine flowers, green tea raw materials (uniform particles).

[0095] Multifunctional scenting equipment (with gas concentration monitoring and control system).

[0096] Liquid chromatography (HPLC) with standard solutions (linalool, phenylethyl alcohol, methyl benzoate).

[0097] Experimental procedures Sample processing Example 2 Sample: Jasmine and green tea were mixed in a mass ratio of 1:5 and placed in a scenting room. The temperature was controlled at 35°C and the humidity was 70%. The gas phase concentration was dynamically regulated in three stages: the initial stage was set at 3.0 mg / L and lasted for 10 hours; the diffusion stage was set at 2.0 mg / L and lasted for 14 hours; the adsorption enhancement stage was set at 1.5 mg / L and lasted for 4 hours, and the total scenting time was 28 hours.

[0098] Comparative Example 3 Sample: Jasmine flowers and green tea were mixed in a mass ratio of 1:5 and placed in a scenting room. The scenting temperature and humidity were kept consistent, the gas phase concentration was set to a fixed value of 2.5 mg / L, and the scenting was carried out for 28 hours without stage-by-stage regulation.

[0099] Sample collection and testing After the scenting process is completed, 50 g of the tea sample is randomly taken for analysis of the content of adsorbed aromatic molecules.

[0100] Each set of samples was repeated three times, and the contents of linalool, phenylethanol and methyl benzoate adsorbed into the tea leaves were detected by HPLC, and the peak areas were recorded and the concentrations were calculated.

[0101] Experimental setup The samples of the embodiment and the comparative example were collected separately to ensure the consistency of the experimental conditions, and only the gas phase concentration control mode was changed.

[0102] The experiment was repeated three times and the average value was taken to reduce the experimental error.

[0103] Table name: Effects of different scenting gas phase concentration control modes on the adsorption of aromatic components by tea leaves Experimental Summary The dynamic multi-phase staged scenting process has shown significant advantages in improving the adsorption efficiency of tea. The experimental data clearly show that under the dynamic control mode, the content of linalool and phenylethanol is significantly higher than that of the fixed concentration control group. This improvement is due to the high-concentration aroma environment in the initial stage, which quickly enhances the adsorption capacity of the tea surface, while the subsequent mid-term stable diffusion concentration setting reduces the waste and adsorption saturation problems caused by excessive release. In contrast, the adsorption efficiency of the fixed concentration group was insufficient in both the initial and later stages.

[0104] The key to tea leaves' adsorption of aromatic molecules lies in the concentration gradient of gas-phase molecules and adsorption kinetics. Dynamic regulation releases high-concentration aromas in stages to form a strong concentration gradient, which promotes the directional diffusion of aromatic molecules to the surface of tea leaves. Combined with the aroma kinetics mechanism, this process optimizes the molecular mass transfer efficiency while ensuring the uniformity of adsorption. The fixed concentration group, due to the lack of regulation of concentration fluctuations, failed to provide sufficient molecular diffusion power during the high adsorption demand stage, which directly led to low adsorption efficiency.

[0105] The difference in gas phase regulation mode also lies in the uniformity of adsorption. Dynamic regulation not only increases the overall adsorption amount, but also effectively reduces the adsorption difference between tea particles, showing better aroma consistency. This is particularly important in combination with the multi-phase stage setting, especially in the combination of diffusion and intensification stages, the full contact between tea and gas phase is guaranteed. The single setting of the fixed concentration mode significantly reduces the sustainability of adsorption in the later stage, affecting the overall aroma persistence of the tea.

[0106] Experimental Example 3: Effect of tail gas recovery and reinjection on resource utilization Purpose Verify the resource utilization effect of tail gas molecular sieve adsorption and condensation recovery technology, and evaluate the recovery efficiency of aromatic components in tail gas and the ability to reduce waste by comparing the recovery and direct emission processes.

[0107] Experimental materials and equipment Multifunctional smelling room with exhaust gas collection and discharge pipes.

[0108] Molecular sieve adsorption device (pore size 0.4nm), condensation recovery system (primary condensation temperature 35℃, deep condensation temperature 8℃).

[0109] Gas chromatography-mass spectrometry (GC-MS).

[0110] Jasmine and tea mixed sample (at a ratio of 1:5).

[0111] Experimental procedures Sample processing Example 3 Sample: The tail gas is passed through a molecular sieve adsorption device (pore size 0.4 nm), and after gas filtration, it enters a two-stage condensation device (primary condensation temperature 35°C, deep condensation temperature 8°C). The condensed liquid aromatic components are collected and returned to the scenting room for recycling. The total tail gas flow and molecular sieve adsorption quality are recorded during the scenting process.

[0112] Comparative Example 2 Sample: The tail gas was not treated in any way and was directly discharged from the scenting room through the discharge pipe. The total flow rate and the concentration of the main aromatic components of the tail gas during the scenting process were recorded.

[0113] Exhaust gas collection and detection A gas sampling device was used to collect samples from the exhaust gas outlet of the scenting room every hour to measure the mass concentration of aromatic molecules (including linalool, phenylethyl alcohol and methyl benzoate) in the exhaust gas.

[0114] For Example 3, the total mass of the aromatic liquid recovered by the molecular sieve device and the condensation device was recorded, and the aromatic molecule content therein was analyzed.

[0115] Experimental setup The temperature of the scenting room was set at 30°C, the humidity was 65%, and the gas phase concentration was dynamically controlled. The total scenting time was 28 hours. The two groups of experiments were repeated 3 times and the average value was taken.

[0116] Table name: Effect of tail gas recovery and direct emission on the utilization rate of aromatic components The tail gas recovery technology significantly reduces the emission of aromatic molecules and realizes efficient resource recycling. The data show that the emission of linalool and phenylethyl alcohol in the tail gas of Example 3 is reduced by more than 70% compared with direct emission. Through the combination of molecular sieve adsorption and condensation recovery, the aromatic molecules that were originally easily wasted are effectively recovered and reused, ultimately making the scenting process greener and more efficient. This difference highlights the high selectivity of the tail gas recovery device in capturing volatile aromatic substances.

[0117] The core of tail gas treatment lies in capture efficiency and separation effect. The molecular sieve selectively adsorbs aromatic molecules through its specific pore size, significantly reducing the loss of aromatic components in the gas phase. The condensing device further converts the gas phase molecules into liquid phase by lowering the temperature, thereby stably storing them. In Comparative Example 2, the tail gas is discharged directly without treatment, resulting in a large number of aromatic molecules being lost with the airflow, which is a resource waste problem that is difficult to avoid in traditional scenting processes. Through mechanism analysis, this waste is mainly due to the uncontrolled diffusion of the gas phase, and the introduction of recovery technology has effectively changed this situation.

[0118] In addition, the concentration of various main components in the recovered aromatic liquid is high and uniform, which provides the possibility for secondary utilization. In Example 3, the recovered liquid is reinjected to make the scenting process more efficient, while the comparative example 2 of the untreated tail gas cannot achieve this cycle optimization. Combined with the data, it is speculated that this tail gas treatment method not only reduces production costs, but also significantly improves the utilization rate of aroma, which is a direct innovation of the traditional scenting process.

[0119] Experimental Example 4: Effect of combined drying process on tea aroma retention rate Purpose Verify the effect of the combined low-temperature drying process (microwave + infrared + vacuum) on improving the aroma retention rate of tea after drying, and evaluate its superiority over traditional high-temperature hot air drying.

[0120] Experimental materials and equipment Jasmine tea that has been scented (produced under the same scenting conditions).

[0121] Microwave drying equipment, infrared drying device, vacuum drying oven.

[0122] Hot air drying equipment (comparative experiment).

[0123] Electronic nose device, liquid chromatography (HPLC), standard solutions (linalool, phenylethyl alcohol, methyl benzoate).

[0124] Experimental procedures Sample processing Example 4 Sample: The scented tea leaves are treated by a combined drying process: Microwave drying: power 2.5 kW, temperature 45°C, time 12 minutes.

[0125] Infrared drying: temperature 55°C, time 8 minutes.

[0126] Vacuum drying: the temperature is controlled below 48°C, the vacuum pressure is 0.03MPa, and the time is 50 minutes.

[0127] Comparative Example 4 Sample: The scented tea leaves were dried using high-temperature hot air at a temperature of 80°C for 60 minutes.

[0128] Aroma detection The overall aroma intensity of the dried tea leaves was detected using an electronic nose device, recording the signal peaks of volatile aromatic molecules.

[0129] HPLC was used to detect the residual concentrations of the main aromatic molecules (linalool, phenylethyl alcohol, and methyl benzoate) in tea and analyze the aroma retention rate.

[0130] Experimental setup The experiments were completed under the same scenting conditions, with the drying process being the only variable.

[0131] Each group of samples was measured three times and the average value was taken to reduce the error.

[0132] Table name: Effect of different drying processes on tea aroma retention rate The combined drying process significantly improves the aroma retention rate of tea. The experimental results show that the residual amounts of linalool and phenylethanol in the sample of Example 4 are higher than those in the high-temperature hot air drying group. The rapid dehydration effect of microwave drying avoids the thermal damage of aroma molecules by high temperature, while infrared drying stabilizes the distribution of aroma molecules, and vacuum drying further reduces oxidation losses in a low-oxygen environment. In contrast, the hot air drying of Comparative Example 4 causes a large amount of aromatic molecules to volatilize under high temperature conditions, resulting in significant aroma loss, and the electronic nose data also reflects that its signal peak is significantly lower than that of the embodiment.

[0133] The effect of the drying process on the stability of aromatic molecules is directly related to the drying temperature and environmental conditions. The internal heating mechanism of microwave drying evenly distributes heat in the tea leaves through the rapid oscillation of water molecules, avoiding the volatilization of aromatic molecules caused by surface overheating. Infrared drying further consolidates the lock of aroma through non-contact thermal radiation. Vacuum drying reduces oxidation reactions by lowering the ambient air pressure. These processes work synergistically, making the aromatic component content of the sample in the example not only high but also more stable.

[0134] Another key factor in aroma loss is the dynamic change of drying time and moisture content. The combined process greatly shortens the time of the high humidity stage through the staged dehydration and aroma locking design, thereby reducing the loss of volatile aroma molecules. In the comparative example, high-temperature hot air drying, due to high-temperature direct heating and long-term treatment, causes sensitive molecules such as linalool and phenylethanol to evaporate quickly, and forms irreversible aroma loss in the later low-humidity stage. This phenomenon is clearly reflected in the experimental data.

[0135] Experimental Example 5: Effects of humidity control and exhaust gas circulation on the consistency of scenting effect Purpose Verify the impact of precise humidity control and exhaust gas recycling technology on the aroma uniformity and overall quality of scented tea, and evaluate its contribution to product consistency and aroma adsorption by comparing with processes without humidity control and exhaust gas recovery.

[0136] Experimental materials and equipment Jasmine and green tea blend (1:5 ratio).

[0137] Fumigation equipment with humidity control module and exhaust gas recirculation system.

[0138] Standard scoring table for sensory evaluation (based on GB / T23776).

[0139] Liquid chromatography (HPLC), aromatic molecule standard solution (linalool, phenylethyl alcohol, methyl benzoate).

[0140] Experimental procedures Scenting settings Example 5 Sample: Humidity is precisely controlled at 65%-70%, tail gas concentration is monitored and recycled into the circulation system (concentration 1.2 mg / L, 6 cycles of injection). Scenting temperature is 35°C, time is 28 hours.

[0141] Comparative Example 5: The humidity was not controlled, and the natural fluctuation was between 50% and 80%. The tail gas was directly discharged without recovery and circulation. The temperature and time of the scenting were the same.

[0142] Sample collection After each group of scenting is completed, equal amounts of tea samples are taken from the upper, middle and bottom layers for aroma uniformity testing.

[0143] The scented tea leaves are sent to 10 professional judges for sensory evaluation, including indicators such as aroma intensity, consistency and tea soup taste.

[0144] Detection Methods Uniformity detection: The contents of main aromatic molecules (linalool, phenylethyl alcohol, methyl benzoate) were detected in samples of different levels, and the data were recorded by HPLC to calculate the uniformity of aroma distribution among tea leaves.

[0145] Sensory scoring: Each reviewer conducted a blind evaluation of the samples, with a score range of 1-10 and the average value was taken.

[0146] Table name: Effects of humidity control and exhaust gas circulation on tea aroma uniformity and sensory scores Experimental Summary The technology of precise humidity control and tail gas circulation plays a vital role in improving the consistency of the quality of scented tea. The experimental data clearly show that the aroma distribution of the example samples is more uniform, and the difference in the linalool content in the upper, middle and lower layers of tea is small, while there is a significant unevenness in the comparative samples, especially the aromatic molecule content of the bottom layer of tea is obviously insufficient. This difference is mainly due to the decrease in the diffusion and adsorption efficiency of aroma molecules in the environment when the humidity is not controlled. At the same time, the direct emission of tail gas leads to the continuous loss of high-concentration aromatic molecules, which in turn affects the overall adsorption effect of tea.

[0147] Humidity balances and promotes the process of tea leaves adsorbing aromatic molecules. Controlling the humidity within the range of 65%-70% can significantly reduce the aroma volatilization caused by moisture fluctuations and accelerate the adsorption kinetics of gas-phase aromatic molecules on the surface of tea leaves. In the comparative example, the humidity naturally changes greatly. The aroma volatilization rate is too fast under low humidity conditions, while the high humidity environment inhibits the release and diffusion of the aroma, resulting in uneven adsorption between tea leaves. Combined with the mechanism analysis, this humidity instability directly affects the dynamic balance of aromatic molecules in the entire scenting environment.

[0148] The tail gas circulation further optimizes the controllability of the gas phase concentration. By injecting high-concentration tail gas in multiple cycles, the example sample achieves a long-term efficient adsorption environment. This method effectively compensates for the loss during the natural release of the aroma and maintains the stability of the aroma concentration. In the comparative example, the direct emission of tail gas caused a large amount of resource waste, and the gas phase concentration could not continuously meet the adsorption requirements, resulting in inconsistency in the quality of tea. From the experimental results, the sensory evaluation also clearly reflects the difference between the two processes. The tail gas circulation and humidity control jointly ensure the richness and uniformity of the tea aroma, which is significantly better than the traditional method.

[0149] 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 clean production process for jasmine tea, characterized in that: The following steps are involved: S1. Composite excitation pretreatment of jasmine flowers: ultrasonic treatment and ozone activation treatment of fresh jasmine flowers; S2. Low-temperature dynamic multi-phase scenting: Mix the processed jasmine flowers with tea leaves and perform multi-stage scenting using a partitioned dynamic gas phase control system; S3, aroma capture and re-injection: the unabsorbed aroma components in the scenting tail gas are captured through molecular sieve adsorption and condensation recovery technology, and recycled into the scenting room; S4. Comprehensive drying of tea leaves and residual flowers: The tea leaves after scenting are dried by a combination of microwave drying, infrared drying and vacuum drying; the residual flowers after scenting are subjected to water extraction, alcohol precipitation and fermentation transformation.

2. A jasmine tea clean production process according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic treatment of the jasmine in step S1 is 20 to 50 kHz, the power density is 0.3 to 0.6 W / cm², and the treatment time is 5 to 10 minutes.

3. A clean production process for jasmine tea according to claim 1, characterized in that: The ozone concentration of the ozone activation treatment in step S1 is 5-10 ppm, the treatment time is 3-7 minutes, the ozone flow rate is 1-2 L / min, and the pressure is 0.05-0.1 MPa.

4. A clean production process for jasmine tea according to claim 1, characterized in that: In the step S2, the temperature of the scenting is 30-40° C., the humidity is 60%-75%, and the gas phase flow rate is 0.5-1.0 m / s.

5. A clean production process for jasmine tea according to claim 1, characterized in that: The multi-stage scenting in step S2 includes: Initial enhancement stage: gas phase concentration is 2.0-3.0 mg / L, and the duration is 6-12 hours; Uniform diffusion stage: gas phase concentration is 1.5-2.0 mg / L, time is 8-16 hours; Adsorption enhancement stage: gas phase concentration is 1.0-1.5 mg / L, and the time is 4-8 hours.

6. A clean production process for jasmine tea according to claim 1, characterized in that: In step S3, the tail gas is captured by a molecular sieve adsorption device, the pore size of the molecular sieve is 0.3-0.5 nm, and the tail gas flow rate is 0.8-1.5 m / s.

7. A clean production process for jasmine tea according to claim 1, characterized in that: The condensation recovery in step S3 includes two-stage condensation: the primary condensation temperature is 30-40°C, and the deep condensation temperature is 5-10°C.

8. A clean production process for jasmine tea according to claim 1, characterized in that: In step S4, the microwave drying power of the tea leaves is 2-3 kW, the temperature is 40-50° C., and the time is 10-15 minutes.

9. A clean production process for jasmine tea according to claim 1, characterized in that: In step S4, the infrared drying temperature is 50-60° C., the time is 5-10 minutes, and the vacuum drying temperature is 40-50° C., the vacuum pressure is 0.02-0.05 MPa, and the time is 30-60 minutes.

10. The clean production process of jasmine tea according to claim 1, characterized in that: When the residual flowers are subjected to water extraction and alcohol precipitation treatment in step S4, the mass ratio of water to residual flowers is 1:10-1:15, the extraction temperature is 60° C., the extraction time is 1 hour, and the ethanol concentration of the alcohol precipitation is 70%-90%.

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