CN107047895A - A kind of preparation method of celery leaf tea - Google Patents

Abstract

The invention relates to the technical field of tea processing, in particular to a method for preparing celery leaf tea. It changes the status quo that celery leaves can only be used as process waste, and brings a new way for the processing and utilization of celery leaves and value-added and efficiency enhancement. In the invention, after the celery leaves are withered, aired and greened, steam is combined with microwaves to fix the greens, and after kneading, medium and short-wave infrared are used to dry the tea leaves, and the celery leaf semi-fermented tea is obtained through a suitable brewing process. The prepared celery leaf tea is firm and solid, dark green in color, rich in aroma, bright in color after brewing, fresh and mellow in taste, and has health benefits such as blood pressure reduction, fat reduction, and anti-oxidation.

Description

A kind of preparation method of celery leaf tea

technical field

The invention relates to the technical field of tea processing, in particular to a method for preparing celery leaf semi-fermented tea with antioxidant activity.

Background technique

According to statistics, there are more than 6,000 varieties of Chinese tea. The more common classification method in the world is to classify according to the production method, which is divided into three categories, namely non-fermented tea, semi-fermented tea, and fully fermented tea. During the production process, the chlorophyll in the tea is destroyed, and the degree of fermentation varies from 20% to 70%, which is semi-fermented tea. Semi-fermented tea combines the production methods of fermented tea and non-fermented tea. The quality is between the two. It has both the strong flavor of fermented tea and the fragrance of non-fermented tea, so it has "green leaves and red borders" reputation.

In the actual production of semi-fermented tea, the way of frying greens is basically adopted. But stir-frying has strict requirements on the amount of leaves and temperature, which is difficult to control. If the amount of leaves is too much, the stir-frying will be uneven, the temperature will rise slowly, and the frying time will be long, and the fried green leaves will easily produce an abnormal dull yellow smell; If the frying temperature is too high, the leaves tend to be scorched and uneven, and the contents cannot be transformed normally. Therefore, if the temperature is too high, the color of the outer leaves will be affected, causing it to lose its tender green color and become off-white; if the temperature is too low, the tea leaves will not be fully ripe, the aroma will be low, the taste will be light, and the soup will be turbid.

In the actual production of semi-fermented tea, the drying method of hot air drying is basically adopted. However, the thermal efficiency of air-heat drying is low, the loss of heat-sensitive nutrients such as vitamins or active ingredients is relatively large, and the quality of finished tea is not stable enough.

Celery is an annual or perennial herb of the Umbelliferae family. Celery leaves are typical dark green vegetables with much higher nutritional and health value than celery stems. They are rich in protein, fat, carbohydrates, dietary fiber, various vitamins and manganese. , zinc, copper, phosphorus, selenium and other trace elements. The protein content of celery leaves exceeds that of most root vegetables. Celery contains a unique ingredient - apigenin, which is a naturally occurring flavonoid. Apigenin has anti-inflammatory, antihypertensive, anti-allergic and other biological effects. Other polyphenolic flavonoids such as gallic acid contained in celery have good antioxidant effects and can prevent aging, arteriosclerosis, and cardiovascular diseases. Therefore, celery has long been dubbed the reputation of "medicine celery" by people.

In the past ten years, the planting area of celery in my country has remained relatively stable at about 550,000 hectares, accounting for 3% of the total vegetable area, with a total output of about 20 million tons. At the same time, when products such as industrialized production and processing of celery juice, in order to alleviate the bitter taste of the product, before squeezing the juice, it should be cut to remove most of the celery leaves. Although the amount of celery leaves is quite considerable, they are basically discarded as waste because there is no good way to process and utilize them. This practice is undoubtedly a great waste of celery leaf resources, and the comprehensive utilization value of celery has not been realized. The invention provides a celery leaf tea and a processing method thereof. The tea has health functions such as reducing blood pressure, reducing fat, and resisting oxidation, and brings a new way for the processing and utilization of celery leaves and value-added and efficiency enhancement.

Contents of the invention

The purpose of the present invention is to overcome the defective that above-mentioned prior art exists, has proposed a kind of preparation method of celery leaf tea, and it can only be used as the present situation of process waste in changing celery leaf, and is the processing utilization and value-added synergistic belt of celery leaf Here comes a new way.

In order to achieve the above object, the technical solution adopted in the present invention is: a kind of preparation method of celery leaf tea, it is characterized in that: the step of described preparation method is:

1) Fresh celery leaves are removed from old, tender, yellow and pest-infested leaves;

2) Wither the celery leaves obtained in step 1): Spread them flat on the tea sample tray with a thickness of 0.4-1cm, wither in sunlight for 20-30 minutes at a temperature of 24-28°C, and turn the celery every 7-9 minutes leaves, celery leaves after wilting;

3) Spread the withered celery leaves in a tea sample tray in a cool place indoors and let them dry for 8-12 minutes to get green celery leaves;

4) In an environment with a temperature of 22-26°C and a relative humidity of 60-80%, green the celery leaves after drying;

5) Use the method of steam combined with microwave to fix green celery leaves to get green celery leaves. The steam fixation time is 90~210s, and the microwave fixation adopts medium heat, medium high heat or high fire, and the fixation time is 70~110s;

6) Alternately knead and bake the celery leaves after greening. Knead lightly at the beginning, then transfer to an oven for initial drying at 80-90°C, then knead again in the middle period, then transfer to an oven for re-drying at 60-70°C after kneading, and knead lightly at a later stage , kneading 3~5 times in total, 4~6min each time;

7) Using a medium-short-wave infrared dryer to dry the celery leaves after kneading at a drying temperature of 40-80°C to obtain dried semi-fermented celery leaf tea with a moisture content of 5-8%.

The greening steps in the step 4) are:

a) Shake green: Use bamboo cradle to flip and shake the blades, the speed is 55~65 rpm;

b) Green spreading: after shaking, the celery leaves are spread in the indoor tea sample tray for green spreading;

c) Shake green and spread green alternately for 3 to 5 times to make green celery leaves.

The tea sample dish is a circular bamboo dish with a diameter of 35 cm.

The cradle described in step 4a) is a cylinder-shaped manual cradle with a length of 45 cm and a diameter of 25 cm.

The steam fixation in step 5) uses atmospheric pressure steam, and the microwave fixation uses a microwave oven with an output power of 700W.

The celery leaf tea is semi-fermented tea.

Compared with prior art, the present invention has following advantage and effect:

1) Dark-colored vegetables are rich in nutrients such as calcium, iron, and vitamins. As a typical dark green vegetable, celery leaves contain dietary fiber and polyphenol flavonoids such as apigenin, which have fat-lowering, slimming, anti-oxidation, etc. Health benefits, however, tea polyphenols are astringent and have a certain stimulating effect on the stomach, and the stimulation is stronger in the case of an empty stomach. The semi-fermented tea is made from celery leaves, on the one hand, the polyphenols can be properly enzymatically catalyzed Oxidation, reduce the heavy bitter taste of celery leaves; on the other hand, it can better retain bioactive components such as polyphenols and flavonoids in celery leaves;

2) Finishing adopts steam combined with microwave technology. Steaming can make the temperature of leaves rise rapidly, inactivate the activity of oxidase, and the appropriate heat and humidity to form the necessary quality characteristics of tea can be carried out more fully. Combined microwave combines the advantages of both, which can moderately inactivate oxidase;

3) Drying adopts medium and short wave infrared dryer. Infrared drying is heat transfer in the form of radiation. The infrared wavelength used in infrared drying is about 0.75~4μm, so it is called medium and short wave infrared drying. After celery leaf tea absorbs infrared rays, it causes internal molecules to vibrate, and the rapid collision and friction between molecules are quickly converted into heat energy, which makes the inside and outside of the tea evenly heated, but the penetration ability of infrared rays is poor, so it needs to be turned frequently. Stir it every 20-30 minutes, the taste of celery leaf tea is rich and sweet, and the soup color is clear and bright. Infrared drying technology can improve the thermal efficiency of drying, save energy and improve the quality of tea.

Description of drawings

Fig. 1 is the flowchart of the processing method of celery leaf tea of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Specific tests include:

The following three embodiments all adopt the following materials:

1. Materials

The celery leaves used in the experiment are celery varieties, and the raw materials come from the food processing and distribution workshop of Northwest A&F University.

Remove the leaves that are too old, too tender, yellow, and have diseases and insect pests, and the raw materials of young and strong celery leaves are the best. Different age and tenderness, different ingredients, different physical properties, different greenness, tenderness, rawness and ripeness, uneven drying and wetness, too much powdered tea and broken tea will bring great difficulties to the continuous production of tea. . Over-aged celery leaves have reduced internal substances. Because of the high sugar content, the water is sweet, and it is difficult to knead and the cords are loose, which is not conducive to the release of tea quality. Over-tender celery leaves have insufficient accumulation of internal substances, high freshness, but weak tea quality, and insufficient fiber development. When the greening process is guaranteed to ensure that the green and strong leaves are moderately greened, the young shoots are easy to kill too much, resulting in poor toughness of the finished tea leaves. Hand kneading That is broken.

The sensory evaluation of celery leaf tea refers to the national standard "GBT 23776-2009 "Tea Sensory Evaluation Method", and 10 people (5 males and 5 females) with professional food knowledge are selected as the sensory evaluation personnel. And the bottom of the leaf is evaluated, and the full score is 100 points. The determination of suitable conditions for each process is based on the content of key indicators combined with sensory evaluation results.

Embodiment one:

The step of a kind of preparation method of celery leaf tea is:

1) Fresh celery leaves are removed from old, tender, yellow and pest-infested leaves;

2) Wither the celery leaves obtained in step 1): Spread them flat on the tea sample tray with a thickness of 1 cm, wither in sunlight for 30 minutes at a temperature of 28°C, and turn the celery leaves every 9 minutes to obtain withered celery leaves;

The weight loss rate of celery leaves is controlled at a suitable level of 16.02%, the luster of the leaf surface disappears, and it turns dark green and slightly soft, which is suitable for subsequent processes;

3) Spread the withered celery leaves in a tea sample tray in a cool place indoors and dry them for 12 minutes to obtain dried green celery leaves;

The weight loss rate is controlled at a suitable level of 6.58%. The moisture in each part of the celery leaf is redistributed evenly, the heat is distributed between the leaves, and the leaves are soft. The sensory score is 82.96, which is suitable for subsequent processes.

4) In an environment with a temperature of 26°C and a relative humidity of 80%, green the celery leaves after drying;

The greening steps in the step 4) are:

a) Shake green: Use a bamboo cradle to flip and shake the blades at a speed of 65 rpm;

b) Green spreading: after shaking, the celery leaves are spread in the indoor tea sample tray for green spreading;

c) Shake the greens and spread the greens alternately for 5 times to make green celery leaves;

Light greening: first shake for 2 minutes, green for 0.5 hours, second for 3 minutes, green for 1 hour, third for 6 minutes, green for 1 hour, fourth for 8 minutes, green for 1.5 hours, fifth for 10 minutes, and green for 2 hours. After heavy greening, the green smell of celery leaves basically disappeared, the peroxidase and polyphenol oxidase activities were 189.43 (△OD470/min·g) and 198.64 (△OD420/min·g) respectively, and the polyphenol content was 13.02mg /g, flavonoid content 12.53mg/g.

5) Use steam combined with microwave method to de-enzyme the celery leaves after greening to get celery leaves after de-enzyming. The steam de-enzyming time is 90s, and the microwave de-enzyming adopts high fire, and the de-enzyming time is 70s;

Even if the celery leaf tea has been properly moistened and heated, the killing effect is fast and uniform. The activities of PPO and POD were 3.35 (△OD420/min·g) and 2.18 (△OD470/min·g), respectively, which were relatively low, and the fermentation process of celery leaf tea would continue very slowly.

6) Alternately knead and bake the celery leaves after greening. Knead lightly at the beginning, then transfer to an oven for initial drying at 85°C, knead again in the middle, and then transfer to an oven for re-drying at 65°C after kneading, knead lightly at the later stage, and knead for 5 times, kneading for 4 minutes each time;

The extract content of celery leaf tea that was kneaded 5 times reached 40.59%, and the sliver rate was higher, reaching more than 85%. The cell damage rate was high, and the acidity of the cell juice increased to destroy chlorophyll.

7) Using a medium-short-wave infrared dryer to dry the rolled celery leaves at a drying temperature of 80°C to obtain dried semi-fermented celery leaf tea with a moisture content of 6.03%.

The tea sample dish is a circular bamboo dish with a diameter of 35 cm.

The cradle described in step 4a) is a cylinder-shaped manual cradle with a length of 45 cm and a diameter of 25 cm.

The steam fixation in step 5) uses atmospheric pressure steam, and the microwave fixation uses a microwave oven with an output power of 700W.

The sensory score of the semi-fermented tea celery leaf tea in this example was 84.79.

Brew with water at 100°C for 10 minutes, when the ratio of liquid to material is 110:1mL/g, the maximum amount of tea polyphenols dissolved in celery leaves can reach 12.12mg/g, the proportion of water and tea is appropriate, the tea leaves are fully stretched and soaked, and the tea soup has a strong taste.

Embodiment two:

The step of a kind of preparation method of celery leaf tea is:

1) Fresh celery leaves are removed from old, tender, yellow and pest-infested leaves;

2) Wither the celery leaves obtained in step 1): Spread them flat on a tea sample tray with a thickness of 0.5cm, wither in sunlight for 25 minutes at a temperature of 26°C, and turn the celery leaves every 8 minutes to obtain withered celery leaves ;

The weight loss rate of celery leaves is controlled at a suitable level of 11.76%, the gloss of the leaf surface disappears, turns dark green, slightly soft, and is suitable for subsequent processes;

3) Spread the withered celery leaves in a tea sample tray in a cool place indoors and dry them for 10 minutes to obtain dried green celery leaves;

Spread the celery leaves after withering in tea sample trays in a cool place indoors to dry green respectively. The bamboo tea sample tray is used because it is natural and clean, which can prevent bacteria from multiplying and produce odors, and can circulate air. Spread the celery leaves after withering in a tea sample tray in a cool place indoors and dry them for 10 minutes to obtain celery leaves after drying. The weight loss rate is controlled at a suitable level of 5.08%. The heat is dissipated, the leaves are soft, and the sensory score is 86.4, which is suitable for subsequent processes.

4) In an environment with a temperature of 25°C and a relative humidity of 70%, green the celery leaves after drying;

The greening steps in the step 4) are:

a) Shake green: use bamboo cradle to flip and shake the blades, the speed is 60 rpm;

b) Green spreading: after shaking, the celery leaves are spread in the indoor tea sample tray for green spreading;

c) Shake green and spread green alternately for 4 times to make green celery leaves;

In the process of shaking green, based on the difference in water loss, the soluble substances and water in the stems and veins are transported to the leaves, commonly known as "water leakage", which has a great impact on the aroma and taste of celery leaf tea. Too slow is not conducive to the progress of the water. After shaking, the celery leaves are spread in the indoor tea sample tray for greening. Set three levels of greening: light, medium and severe. The deeper the degree, the longer the number of times of greening, shaking time and spreading time. Moderate greening: 1 shake for 2 minutes, green stand for 0.5 hours, second shake for 3 minutes, green stand for 1 hour, third shake for 8 minutes, green stand for 1 hour, fourth shake for 12 minutes, stand green for 2.5 hours. After moderate greening, the green smell of celery leaves basically disappeared, the peroxidase and polyphenol oxidase activities were 179.70 (△OD470/min·g) and 213.92 (△OD420/min·g), and the polyphenol content was 16.07 mg/g, flavonoid content 15.8mg/g;

5) Use steam combined with microwave method to de-enzyme the green celery leaves to obtain de-enzyme celery leaves, wherein the steam de-enzyme time is 150s, and the microwave de-enzyme adopts medium heat, and the de-enzyme time is 70s;

Steaming for 150s + microwave medium heat for 70s, even though the celery leaf tea has a proper heat and humidity effect, the effect of killing greens is also fast and uniform. The activities of PPO and POD were 2.01 (△OD420/min·g) and 1.76 (△OD470/min·g), respectively, which were relatively low, and the fermentation process of celery leaf tea would continue very slowly.

6) Alternately knead and bake the celery leaves after greening. Knead lightly at the beginning, then transfer to an oven for initial drying at 85°C, knead again in the middle, and then transfer to an oven for re-drying at 65°C after kneading, knead lightly at the later stage, and knead for 5 times, kneading for 5 minutes each time;

Kneading pressure masters "light, heavy, light", because at the beginning, the tea leaves are relatively fragile, and the tea juice has not been kneaded, so it is lightly pressed; when it is in the middle, the tea juice comes out, and the tea leaves are relatively moist, so it can be pressed heavily ; Finally, the tea leaves are basically formed, so as to prevent the strips from being crushed, knead them as gently as possible.

After the celery leaf tea is finished, put it into the white square cloth towel while it is hot, lift the four corners of the square towel, vibrate and tighten it, put it into the kneading machine kneading bucket, knead, knead, squeeze, and press in the bucket, constantly turning and tightening. The extract content of celery leaf tea that was kneaded 4 times reached 39.57%, and the sliver rate was higher, reaching more than 90%. The cell damage rate was high, and the acidity of the cell juice increased to destroy chlorophyll.

7) Using a medium-short-wave infrared dryer to dry the celery leaves after kneading at a drying temperature of 50°C to obtain dried semi-fermented celery leaf tea with a moisture content of 6.1%.

The tea sample dish is a circular bamboo dish with a diameter of 35 cm.

The cradle described in step 4a) is a cylinder-shaped manual cradle with a length of 45 cm and a diameter of 25 cm.

The steam fixation in step 5) uses atmospheric pressure steam, and the microwave fixation uses a microwave oven with an output power of 700W.

The semi-fermented celery leaf tea obtained in Example 2 had a good sensory score, with a score of 87.05.

Effects of different brewing techniques on the quality of celery leaf tea:

Take liquid-to-material ratios of 70:1, 80:1, 90:1, 100:1, and 110:1 mL/g, respectively, and brew them with 90°C water for 6 minutes. When the liquid-to-material ratio is 100:1 mL/g, celery leaf tea The maximum amount of phenol dissolved is 10.90mg/g, the proportion of water and tea is appropriate, the tea leaves are fully stretched and soaked, and the tea soup has a strong taste.

Brewing at 70, 80, 90, 95, and 100°C for 6 minutes at a liquid-to-solid ratio of 100:1mL/g, and brewing at 95°C is conducive to the dissolution of tea polyphenols from celery leaves, with a value of 10.83mg/g.

At 100:1mL/g liquid-to-solid ratio and 95°C, brew for 2, 4, 6, 8, and 10 minutes respectively. When the brewing time is 8 minutes, tea polyphenols in celery leaves have enough time to dissolve, and the content is 10.84mg/g , basically does not cause oxidation of polyphenols.

Embodiment three:

The step of a kind of preparation method of celery leaf tea is:

1) Fresh celery leaves are removed from old, tender, yellow and pest-infested leaves;

2) Wither the celery leaves obtained in step 1): Spread them flat on a tea sample tray with a thickness of 0.4cm, wither in sunlight for 20 minutes at a temperature of 24°C, and turn the celery leaves every 7 minutes to obtain withered celery leaves ;

The weight loss rate of celery leaves is controlled at a suitable level of 10.57%, and the gloss of the leaves disappears, turning dark green and slightly soft, which is suitable for subsequent processes.

3) Spread the withered celery leaves in a tea sample tray in a cool place indoors and dry them for 8 minutes to obtain dried green celery leaves;

The weight loss rate is controlled at a suitable level of 4.58%. The water redistribution in each part of the celery leaf is even, the heat is dissipated between the leaves, and the leaves are soft. The sensory score is 83.59, which is suitable for subsequent processes.

4) In an environment with a temperature of 22°C and a relative humidity of 60%, green the celery leaves after drying;

The greening steps in the step 4) are as follows:

a) Shake green: Use a bamboo cradle to turn over and shake the blades at a speed of 55 rpm;

b) Green spreading: after shaking, the celery leaves are spread in the indoor tea sample tray for green spreading;

c) Shake green and spread green alternately for 3 times to make green celery leaves;

Light greening: first shake for 3 minutes, green for 1 hour, second shake for 6 minutes, green for 1 hour, third shake for 8 minutes, green for 2.5 hours. After light greening, the green smell of celery leaves basically disappeared, the peroxidase and polyphenol oxidase activities were 91.37 (△OD470/min·g) and 280.50 (△OD420/min·g), and the polyphenol content was 18.61 mg/g, flavonoid content 14.02mg/g.

5) Use steam combined with microwave method to de-enzyme the celery leaves after greening to get celery leaves after de-enzyming. The steam de-enzyming time is 180s, and the microwave de-enzyming uses high fire, and the de-enzyming time is 70s;

Even if the celery leaf tea has been properly moistened and heated, the killing effect is fast and uniform. The activities of PPO and POD were 1.85 (△OD420/min·g) and 1.44 (△OD470/min·g), respectively, which were relatively low, and the fermentation process of celery leaf tea would continue very slowly.

6) Alternately knead and bake the celery leaves after greening. Knead lightly at the beginning, then transfer to an oven for initial drying at 85°C, knead again in the middle, and then transfer to an oven for re-drying at 65°C after kneading, knead lightly at a later stage, and knead for 3 times, kneading for 5 minutes each time;

The extract content of celery leaf tea that has been kneaded 3 times reaches 36.76%, the slitting rate is as high as 85%, the cell damage rate is high, the acidity of the cell juice increases and destroys chlorophyll, and the chlorophyll content is 1056.89μg/g;

7) Using a medium-short-wave infrared dryer to dry the celery leaves after kneading at a drying temperature of 40°C to obtain dried semi-fermented celery leaf tea with a moisture content of 6.98%.

The tea sample dish is a circular bamboo dish with a diameter of 35 cm.

The cradle described in step 4a) is a cylinder-shaped manual cradle with a length of 45 cm and a diameter of 25 cm.

The steam fixation in step 5) uses atmospheric pressure steam, and the microwave fixation uses a microwave oven with an output power of 700W.

The semi-fermented celery leaf tea obtained in this example had a good sensory score, with a score of 85.44.

Effects of different brewing techniques on the quality of celery leaf tea

Brew with water at 70°C for 2 minutes, when the ratio of liquid to material is 70:1mL/g, the maximum amount of tea polyphenols dissolved in celery leaves can reach 8.30mg/g, the proportion of water to tea is appropriate, the tea leaves are basically stretched and soaked, and the tea soup has a strong taste.

Claims (6)

1. a preparation method of celery leaf tea, is characterized in that: the step of described preparation method is: 1) Fresh celery leaves are removed from old, tender, yellow and pest-infested leaves; 2) Wither the celery leaves obtained in step 1): Spread them flat on the tea sample tray with a thickness of 0.4-1cm, wither in sunlight for 20-30 minutes at a temperature of 24-28°C, and turn the celery every 7-9 minutes leaves, celery leaves after wilting; 3) Spread the withered celery leaves in a tea sample tray in a cool place indoors and let them dry for 8-12 minutes to get green celery leaves; 4) In an environment with a temperature of 22-26°C and a relative humidity of 60-80%, green the celery leaves after drying; 5) Use the method of steam combined with microwave to fix green celery leaves to get green celery leaves. The steam fixation time is 90~210s, and the microwave fixation adopts medium heat, medium high heat or high fire, and the fixation time is 70~110s; 6) Alternately knead and bake the celery leaves after greening. Knead lightly at the beginning, then transfer to an oven for initial drying at 80-90°C, then knead again in the middle period, then transfer to an oven for re-drying at 60-70°C after kneading, and knead lightly at a later stage , kneading 3~5 times in total, 4~6min each time; 7) Using a medium-short-wave infrared dryer to dry the celery leaves after kneading at a drying temperature of 40-80°C to obtain dried semi-fermented celery leaf tea with a moisture content of 5-8%. 2. The preparation method of a kind of celery leaf tea according to claim 1, characterized in that: the greening step in the step 4) is: a) Shake green: Use bamboo cradle to flip and shake the blades, the speed is 55~65 rpm; b) Green spreading: after shaking, the celery leaves are spread in the indoor tea sample tray for green spreading; c) Shake green and spread green alternately for 3 to 5 times to make green celery leaves. 3. The preparation method of a kind of celery leaf tea according to claim 1, characterized in that: the tea sample dish is a circular bamboo dish with a diameter of 35cm. 4. The method for making celery leaf tea according to claim 3, characterized in that: the cradle described in step 4a) is a cylinder-shaped manual cradle with a length of 45 cm and a diameter of 25 cm. 5. A method for making celery leaf tea according to claim 4, characterized in that: the steam finishing described in step 5) uses atmospheric pressure steam, and the microwave finishing uses a microwave oven with an output power of 700W . 6. The preparation method of a kind of celery leaf tea according to claim 1, characterized in that: said celery leaf tea is semi-fermented tea.