A kind of Alpinia officinalis leaf compressed tea and preparation method thereof

Abstract

The present invention relates to the field of food processing, and in particular to a Ligustrum lucidum leaf compressed tea and a preparation method thereof. The preparation method of the Ligustrum lucidum leaf compressed tea provided by the present invention comprises the following steps: subjecting Ligustrum lucidum leaf fresh leaves to a first withering, shaking, a second withering, a third withering and drying in sequence to obtain Ligustrum lucidum leaf loose tea; and steaming, pressing and drying the Ligustrum lucidum leaf loose tea to obtain Ligustrum lucidum leaf compressed tea. The Ligustrum lucidum leaf compressed tea product prepared by the present invention has reduced bitterness, moderate sweetness, light aftertaste and a richer aroma. In addition, the method provided by the present invention can make full use of Ligustrum lucidum leaf resources, especially slightly coarse and old, large-leaf resources. Compared with traditional processes, the Ligustrum lucidum leaf compressed tea prepared by the present invention has a taste that is more easily accepted by consumers, which is conducive to opening up the consumer market.

Description

Technical Field

[0001] The invention relates to the field of tea processing, in particular to a kind of Alpinia zedoaria leaf and keel pressed tea and a preparation method thereof. Background Art

[0002] Lithocarpus litseifolius (Hance) Chun is an evergreen plant of the genus Lithocarpus in the Fagaceae family, commonly known as sweet tea or Xupu Yao tea. Lithocarpus litseifolius mainly contains flavonoids, triterpenes, polyphenols and other ingredients. The National Compilation of Chinese Herbal Medicines records that "Lithocarpus litseifolius leaves have the effect of clearing heat and removing dampness, and can be used for damp-heat dysentery, skin itching, carbuncle, malignant ulcers and other symptoms." Pharmacological studies have shown that Lithocarpus litseifolius has the effects of lowering blood sugar, blood pressure, blood lipids, anti-oxidation, anti-allergy and anti-cancer. In addition, Lithocarpus litseifolius is also a natural sweetener resource, and its sweet ingredients are mainly trifoliate glycosides. Lithocarpus litseifolius has been approved by the National Health and Family Planning Commission for use as a new resource food (No. 7 of 2017), and is known as the "tree cordyceps", which is of great development value.

[0003] At present, the utilization of Ligusticum chuanxiong resources is relatively single, mainly developing Ligusticum chuanxiong tender leaves into green tea, instant tea, etc., not only the product variety is single, but also the slightly coarse and old, large leaf resources have not been well developed and utilized. At this stage, the relatively single product form of Ligusticum chuanxiong not only cannot meet the needs of consumers, but also cannot fully utilize Ligusticum chuanxiong resources. In addition, the current Ligusticum chuanxiong tea products are too sweet and have a bitter taste; many consumers do not like this taste, which reduces its market acceptance and seriously hinders the development of the Ligusticum chuanxiong industry. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a Ligustrum lucidum leaf compressed tea and a preparation method thereof. The preparation method provided by the present invention can obtain a Ligustrum lucidum leaf compressed tea with a sweet taste, and the method can make full use of Ligustrum lucidum leaf resources, especially slightly coarse and old, large leaf resources can produce compressed tea with good taste and aroma. The finished Ligustrum lucidum leaf compressed tea produced by the present invention has low bitterness, moderate sweetness, light aftertaste, and a stronger aroma.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The invention provides a method for preparing a compressed tea of ​​Ligusticum chuanxiong leaves and branches, comprising the following steps:

[0007] The fresh leaves of Ligustrum lucidum are sequentially subjected to first withering, shaking, second withering, third withering and drying to obtain Ligustrum lucidum loose tea;

[0008] The loose tea of ​​Ligustrum lucidum is sequentially steamed, pressed and dried to obtain Ligustrum lucidum compressed tea.

[0009] Preferably, the shaking time is 35 to 50 minutes.

[0010] Preferably, the first withering is a first indoor withering; the temperature of the first withering is 25-32° C.; the water content of the leaves obtained by the first withering is 60wt.%-65wt.%;

[0011] The second withering is outdoor withering; the outdoor withering comprises: placing the leaf raw material after shaking under the sun for 3 hours when the sunlight is weak; the water content of the leaves obtained by the second withering is 42wt.% to 47wt.%;

[0012] The third withering method is the second indoor withering; the temperature of the third withering is 25-32° C.; the water content of the leaves obtained by the third withering is 22wt.%-27wt.%.

[0013] Preferably, the fresh leaves of the Ligusticum chuanxiong include young leaves of the Ligusticum chuanxiong and / or slightly coarse, old and large leaves of the Ligusticum chuanxiong.

[0014] Preferably, the drying temperature is 45±5°C; and the water content of the loose tea of ​​Alpinia officinalis is 5wt.%.

[0015] Preferably, after the second withering, screening is also included; the thickness of the leaves after screening is 1 to 2 cm.

[0016] Preferably, the tea steaming time is 2 minutes; the drying temperature is 40-50° C.; and the water content of the dried tea obtained by drying is ≤5wt.%.

[0017] The invention provides a compressed tea of ​​the leaves of the elm of Ligustrum lucidum prepared by the preparation method described in the technical scheme, wherein the content of trilobatin in the compressed tea of ​​the leaves of the elm of Ligustrum lucidum is 64.631-70.351 mg / g, the content of phlorizin is 4.812-6.072 mg / g, the content of 3-hydroxyphlorizin is 1.413-1.653 mg / g, the content of neohesperidin dihydrochalcone is 0.021-0.161 mg / g, and the content of phlorizin is 1.641-3.401 mg / g.

[0018] Preferably, the moisture content of the Arborvitae compressed tea is 3-5%, the total ash content is 4.5-6.5%, the water extract content is 36-38%, the free amino acid content is 3-4%, the total flavonoids content is 6.5-8%, the tea polyphenols content is 20-24%, theaflavin content is 0.6-0.8%, and thearubigins content is 7.5-9.5%.

[0019] The present invention provides a method for preparing a tea drink of Ligustrum lucidum leaf compressed tea, wherein the Ligustrum lucidum leaf compressed tea is obtained by the preparation method described in the above technical scheme, and the preparation method comprises the following steps: mixing the Ligustrum lucidum leaf compressed tea with water to boil the tea and steam the tea;

[0020] The mass volume ratio of the Ligustrum lucidum leaf compressed tea to water is 6g:1100mL; the time for boiling the tea is 10min; and the time for steaming the tea is 2min.

[0021] Beneficial effects: The present invention provides a method for making Ligustrum lucidum compressed tea, the method comprising the following steps: subjecting Ligustrum lucidum fresh leaves to a first withering, a shaking, a second withering, a third withering, a fourth withering and drying in sequence to obtain Ligustrum lucidum loose tea; subjecting the Ligustrum lucidum loose tea to a steaming, pressing and drying in sequence to obtain Ligustrum lucidum compressed tea. The present invention creatively adds the shaking process during the withering process of Ligustrum lucidum compressed tea, thereby improving the aroma, types and contents of biochemical components in Ligustrum lucidum compressed tea, and improving the sensory quality of Ligustrum lucidum compressed tea; the method of the present invention can be used to process compressed tea products with excellent comprehensive quality in appearance, aroma, taste and shape. When the prior art prepares green tea from Litsea cubeba, the fresh leaves of Litsea cubeba are directly treated with withering, and the green tea product finally obtained retains a high content of sweet substances, mainly sweet substances such as trifoliatin, phlorizin, neohesperidin dihydrochalcone, phlorizin, 3-hydroxyphlorizin, etc., resulting in a particularly sweet taste, which is difficult for many consumers to accept. In addition, the content of tannins in the tea polyphenols in the green tea is also relatively high, so the sweet taste is also relatively heavy. Therefore, Litsea cubeba green tea is not popular with consumers. The present invention withers and dries, so that the compressed tea has a low content of sweet substances and a relatively low content of tea polyphenols tannins, and is combined with steaming and low-temperature drying during cake pressing, so that the finally obtained finished product has reduced bitterness, moderate sweetness, light sweetness, and a stronger aroma. The tea soup meets the needs of the public, and the acceptance of Litsea cubeba compressed tea products in consumer groups is improved. The results of the embodiments of the present invention show that the compressed tea of ​​the Ligusticum chuanxiong prepared by the method of the present invention has the advantages of being pure and strong, and improves the contents of moisture, total ash and theaflavins in the tea product, and reduces the contents of water extract, free amino acids, total flavonoids, tea polyphenols and thearubigins. Specifically, the moisture content of the Ligusticum chuanxiong compressed tea obtained by the preparation method of the present invention reaches 3.67%, the total ash content reaches 5.31%, the water extract content is reduced to 36.55%, the free amino acid content is reduced to 3.72%, the total flavonoids content is reduced to 7.26%, the tea polyphenols content is reduced to 21.48%, the theaflavins content reaches 0.78%, and the thearubigins content is reduced to 8.98%.

[0022] Moreover, the production method provided by the present invention uses fresh leaves of the Ligustrum lucidum as raw materials, and is not limited to tender leaves, thereby realizing the comprehensive utilization of the Ligustrum lucidum leaf resources; at the same time, the Ligustrum lucidum compressed tea produced by the present invention is easy to brew, has a golden soup color, and tastes sweet. Compared with traditional green tea, the acceptance of the Ligustrum lucidum compressed tea among consumers is greatly improved, and the market scope has been greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0024] Figure 1 The compressed tea made from the leaves and branches of the Alpinia zeylanicum of the present invention;

[0025] Figure 2 The tea base of the Alpinia officinalis leaf and branch compressed tea produced by the present invention;

[0026] Figure 3 The tea soup of the compressed tea made from the leaves and branches of the Alpinia officinalis of the present invention;

[0027] Figure 4 is a mixed standard curve;

[0028] Figure 5 is the standard curve of trilobatin;

[0029] Figure 6 is the standard curve of phlorizin;

[0030] Figure 7 is the standard curve of 3-hydroxyphlorizin;

[0031] Figure 8 This is the standard curve of neohesperidin dihydrochalcone;

[0032] Fig. 9 This is the standard curve of phloretin. DETAILED DESCRIPTION

[0033] The present invention provides a method for preparing a compressed tea of ​​Ligustrum lucidum leaf and branch, the method comprising the following steps:

[0034] The fresh leaves of Ligustrum lucidum are sequentially subjected to first withering, shaking, second withering, third withering and drying to obtain Ligustrum lucidum loose tea;

[0035] The loose tea of ​​Ligustrum lucidum is sequentially steamed, pressed and dried to obtain Ligustrum lucidum compressed tea.

[0036] The present invention performs a first withering on fresh leaves of the Ligustrum lucidum to obtain primary withered tea leaves. The fresh leaves of the Ligustrum lucidum described in the present invention preferably include tender leaves of the Ligustrum lucidum and / or slightly coarse, old and large leaves of the Ligustrum lucidum, more preferably tender leaves of the Ligustrum lucidum; the slightly coarse, old and large leaves of the Ligustrum lucidum are preferably large leaves of the Ligustrum lucidum grown in the current year. The leaves of the Ligustrum lucidum are relatively large, and the tenderest part of the leaves is generally processed into green tea in the prior art; while the slightly coarse, old and large leaves grown in the current year cannot be rolled and shaped, and it is difficult to process them into green tea. The production method described in the present invention can utilize the tender leaves and slightly coarse, old and large leaves of the Ligustrum lucidum, so that the Ligustrum lucidum can be fully utilized to reduce waste.

[0037] In the present invention, the preferred method for picking fresh leaves of the Ligusticum chuanxiong is as follows: on a sunny day, pick the fresh leaves of the Ligusticum chuanxiongong after the dew has dried up. The utensils and transportation vehicles for holding the fresh leaves must have good air permeability, avoid squeezing and long-term stacking, avoid exposure to sunlight, and avoid the fresh leaves from being worn and turned red.

[0038] The first withering method of the present invention is preferably the first indoor withering; the indoor withering method is preferably temperature-controlled withering in a withering trough; direct exposure to natural light is avoided during indoor withering; the temperature of the first withering is preferably 25-32°C, more preferably 27-30°C; the stacking thickness of the leaves used for the first withering is preferably 0.5-1.0 cm, more preferably 0.7-0.9 cm. The moisture content of the primary withered tea leaves of the present invention is preferably 60wt.%-65wt.%, more preferably 60wt.%.

[0039] Withering is the core of the present invention, and the quality of withering directly determines the quality of a compressed tea. During the withering process, the leaves lose water and are accompanied by respiration, the activity of enzymes is enhanced, macromolecular substances such as protein, starch, and insoluble protopectin are degraded, small molecular glucose, amino acids and other substances beneficial to the quality of the finished tea are increased, and polyphenols are oxidized to varying degrees; during the withering process, the quality of the tea will be affected if the water is lost too quickly or too slowly; and timely sun drying and shaking of the tea promotes aroma conversion.

[0040] After the first withering, the present invention performs shaking of the primary withered tea leaves to obtain shaken tea leaves. The shaking time of the present invention is preferably 35 to 50 minutes, more preferably 40 to 45 minutes, and more preferably 45 minutes. The shaking of the present invention is conducive to removing astringency and inducing aroma, achieving the effect of removing astringency and retaining aroma, and preparing good tea with harmonious taste, aroma and mouthfeel.

[0041] After obtaining the shaking green tea leaves, the present invention performs a second withering on the shaking green tea leaves to obtain intermediate withered tea leaves. The second withering of the present invention is preferably outdoor withering, and the time of the outdoor withering is preferably 3 hours. The outdoor withering of the present invention is preferably performed by placing the shaking green tea leaves in the sun when the sunlight is weak in the morning and / or evening, and the sunlight is gentle at this time, and avoid exposure to the sun at noon. The water content of the intermediate withered tea leaves of the present invention is preferably 42wt.% to 47wt.%, more preferably 45wt.%.

[0042] After obtaining the intermediate withered tea leaves, the present invention preferably further comprises sieving the intermediate withered tea leaves to obtain sifted tea leaves; after the sifting, the thickness of the leaves is preferably 1 to 2 cm; the sifting method is preferably two sieves and one sieve. The present invention can appropriately gather the tea leaves through sifting, slow down the evaporation of water, promote the balanced distribution of water in the leaves, and enhance the permeability of the cell membrane; it can also increase the leaf temperature, continue to promote the enzymatic oxidation degradation, transformation and hydrolysis of polyphenols, pigments and other contained substances, and promote the transformation and formation of aroma components; and sifting can make the effective ingredients in the stem veins transported to the mesophyll cells along with the water, so that the withered leaves will show a recovery phenomenon, further promoting the transformation of substances; at the same time, the present invention changes the state of the leaves through sifting to avoid sticking to the sieve, which is conducive to the curling of the tea leaves and makes the dry tea more stylish. It can be seen that sifting can slow down the loss of water from fresh leaves that lose water quickly, and can also accelerate the loss of water from fresh leaves that lose water slowly, balancing the loss rate and thus achieving the synergistic effect of fresh leaf water loss and substance change.

[0043] After obtaining the intermediate withered tea leaves, the present invention performs a third withering on the intermediate withered tea leaves to obtain high-grade withered tea leaves. The third withering method of the present invention is preferably second indoor withering; the indoor withering method is preferably temperature-controlled withering in a withering trough; the temperature of the third withering is 25 to 32°C, more preferably 27 to 30°C. The moisture content of the high-grade withered tea leaves of the present invention is preferably 22wt.% to 27wt.%, more preferably 25wt.%.

[0044] The invention combines indoor withering and outdoor withering, which is beneficial to the formation of tea aroma and shortens the withering time.

[0045] After obtaining high-grade withered tea leaves, the present invention dries the special-grade withered tea leaves to obtain Ligustrum lucidum loose tea. The drying temperature of the present invention is preferably 40-50°C, more preferably 50°C. The present invention selects slow baking at a low temperature of 45±5°C to further dissipate the moisture in the tea leaves, promote the slow transformation of the contained substances, improve the aroma, etc. The moisture content of the Ligustrum lucidum loose tea of ​​the present invention is preferably 5wt.%.

[0046] After obtaining the loose tea of ​​Ligustrum lucidum, the present invention steams, presses and dries the loose tea of ​​Ligustrum lucidum to obtain Ligustrum lucidum compressed tea. The specific method of steaming tea in the present invention is preferably to mix the loose tea of ​​Ligustrum lucidum with water and steam the tea; the time for steaming the tea is preferably 2 minutes. In an embodiment of the present invention, the loose tea of ​​Ligustrum lucidum is spread on a steamer covered with gauze for steaming. In the present invention, the method of steaming tea can not only make the tea leaves more compact, but also remove the green and astringent smell. The tea leaves treated with steaming are more fragrant and the green and astringent taste is further reduced, and the taste is purer.

[0047] After the tea is steamed, the tea leaves obtained by steaming are pressed to obtain tea cakes; the thickness of the tea cakes is preferably 0.5 cm; the pressing time is preferably 2 to 3 minutes. The steamed tea leaves are evenly placed before pressing to avoid inconsistent thickness of the tea cakes. The size of the pressing mold of the present invention is preferably 5 cm×5 cm; based on the mass of the loose tea of ​​Ligustrum lucidum, the amount of tea leaves in the mold is preferably 8 g.

[0048] After obtaining the tea cake, the present invention dries the tea cake to obtain dried tea. The drying of the present invention is preferably low-temperature slow baking; the drying time is preferably 40 to 48 hours; the drying temperature is preferably 40 to 50°C, more preferably 45 to 50°C; the moisture content of the dried tea is preferably below 5%, more preferably 4wt.% to 5wt.%.

[0049] The present invention combines the two steps of steaming tea and slow baking at low temperature to further remove the astringency of tea leaves and enhance the tea aroma.

[0050] After obtaining the dried tea, the present invention preferably packages the dried tea to obtain the Ligustrum lucidum leaf compressed tea. The present invention has no limitation on the packaging method, and any method known to those skilled in the art can be used. If the Ligustrum lucidum leaf compressed tea is not consumed immediately, the present invention preferably stores the Ligustrum lucidum leaf compressed tea in a cool and dry place.

[0051] The invention provides a compressed tea of ​​the leaves of the ginger genus obtained by the production method described in the technical scheme, wherein the content of trilobatin in the compressed tea is 64.631-70.351 mg / g, the content of phlorizin is 4.812-6.072 mg / g, the content of 3-hydroxyphlorizin is 1.413-1.653 mg / g, the content of neohesperidin dihydrochalcone is 0.021-0.161 mg / g, and the content of phlorizin is 1.641-3.401 mg / g. The moisture content of the compressed tea of ​​the Ligustrum lucidum leaf of the present invention is preferably 3-5%, the total ash content is preferably 4.5-6.5%, the water extract content is preferably 36-38%, the free amino acid content is preferably 3-4%, the total flavonoids content is preferably 6.5-8%, the tea polyphenols content is preferably 20-24%, the theaflavins content is preferably 0.6-0.8%, and the thearubigins content is preferably 7.5-9.5%. The moisture content of the compressed tea of ​​the Ligustrum lucidum leaf is more preferably 3.67%, the total ash content is more preferably 5.31%, the water extract content is more preferably 36.55%, the free amino acid content is more preferably 3.72%, the total flavonoids content is more preferably 7.26%, the tea polyphenols content is more preferably 21.48%, the theaflavins content is more preferably 0.78%, and the thearubigins content is more preferably 8.98%. The Ligustrum lucidum leaf compressed tea provided by the present invention has moderate sweetness, reduced bitterness, light aftertaste, and richer aroma. The tea soup meets the needs of the public, and the acceptance of Ligustrum lucidum leaf compressed tea products among consumer groups is improved; and the preparation method of the Ligustrum lucidum leaf compressed tea of ​​the present invention uses Ligustrum lucidum leaf fresh leaves as raw materials, is not limited to tender leaves, and makes full use of the slightly coarse and old, large leaf resources of Ligustrum lucidum leaf. Therefore, the Ligustrum lucidum leaf compressed tea of ​​the present invention solves many problems in the prior art: 1. Ligustrum lucidum leaf tea products are too sweet, 2. Ligustrum lucidum leaf tea products have a heavy bitter taste, and 3. Ligustrum lucidum leaf slightly coarse and old, large leaf resources are wasted.

[0052] The present invention also provides a method for making a tea drink of Ligustrum lucidum compressed tea, wherein the Ligustrum lucidum compressed tea is obtained by the method described in the above technical solution, and the method comprises the following steps: mixing the Ligustrum lucidum compressed tea with water to boil and stew the tea; the mass volume ratio of the Ligustrum lucidum compressed tea to water is 6g:1100mL; the boiling time is 10min; the stewing time is 2min. The drinking method provided by the present invention can obtain tea with better taste, tea aroma and stronger tea aroma, and can also avoid the situation where the tea is too sweet by controlling the amount of water used. Moreover, the Ligustrum lucidum compressed tea produced by the present invention is easy to brew, has a golden soup color and a sweet taste. Compared with traditional green tea, the Ligustrum lucidum compressed tea has greatly improved its acceptance among consumer groups, and its market scope has been greatly improved.

[0053] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0054] Example 1

[0055] The process flow is: picking → indoor withering → shaking → outdoor withering → screening → indoor withering → drying → steaming tea → pressing → drying.

[0056] ① Tea picking: Collect 20-30 catties of fresh leaves. On a sunny day, after the dew has dried, pick and remove the tender leaves for making green tea. The containers and transportation tools for holding fresh leaves must be well ventilated, avoid squeezing and long-term accumulation, avoid exposure to sunlight, and avoid the fresh leaves from being worn and turned red.

[0057] ② Indoor withering: Indoor withering trough temperature-controlled withering, the indoor temperature is 25-32°C, the stacking thickness of the leaves is 0.5-1.0cm, the withering is about 24 hours, and the moisture content of the obtained tea is about 60wt.%.

[0058] ③Shaking: Shake the tea leaves for 45 minutes.

[0059] ④ Outdoor withering: When the sunlight is gentle, place the fresh leaves in the sun in the morning and evening when the sunlight is weak, and wither for about 3 hours. The moisture content of the obtained tea leaves is about 45wt.%.

[0060] ⑤ Combine two sieves into one sieve. The thickness of the leaves after combined sieving is 1 to 2 cm.

[0061] ⑥ Indoor withering: The steps are the same as step ②, withering at 25-32°C for about 24 hours, and the moisture content of the obtained tea leaves is about 25wt.%.

[0062] ⑦ Drying: The tea leaves obtained in step ⑥ are slowly dried at 45±5℃ to obtain loose tea, i.e. loose tea, also known as raw tea. Figure 2 As shown, the water content of the loose tea of ​​Ligusticum chuanxiong is about 5wt.%.

[0063] ⑧ Steaming tea: Choose a clean pot, add 2L of water, put in a clean steamer, cover the steamer with clean gauze, and spread 8g of the above-mentioned Ligustrum lucidum leaf loose tea on the gauze. Steam for 2 minutes after the water in the pot boils.

[0064] ⑨ Pressing: Take out the steamed tea leaves, put them evenly into the tea pressing instrument, and place them in the center. Be careful to place them evenly to avoid inconsistent thickness of the tea cakes. Use a 5cm*5cm mold to press them into small tea cakes with a thickness of 0.5cm. The pressing time is 2 to 3 minutes.

[0065] ⑩ Drying: Place the tea cakes in a drying oven, arrange them neatly layer by layer, heat and maintain the temperature at 45±5℃, and bake for 40-48h until the moisture content of the tea cakes is below 5wt.%, and obtain the Alpinia officinalis leaf pressed tea. Figure 1 As shown; store in a cool, dry place.

[0066] Comparative Example 1

[0067] ① Tea picking: Collect 20-30 catties of fresh leaves. On a sunny day, after the dew has dried, pick and remove the tender leaves for making green tea. The containers and transportation tools for holding fresh leaves must be well ventilated, avoid squeezing and long-term accumulation, avoid exposure to sunlight, and avoid the fresh leaves from being worn and turned red.

[0068] ② Indoor withering: Temperature-controlled withering in indoor withering troughs, with ventilation on all sides and no direct exposure, at 25-32°C, with a leaf thickness of 0.5-1.0 cm, withering for about 24 hours, the moisture content of the obtained tea is about 35wt.%.

[0069] Comparative Example 2

[0070] The steps are the same as those in Comparative Example 1, except that the indoor withering time is 48 hours.

[0071] Comparative Example 3

[0072] Green tea production method:

[0073] (1) Process flow: spreading → killing green → rolling → cooling → rolling → low temperature drying and dehydration → rolling → tumbling → frying → low temperature drying → screening → aroma enhancement → finished product.

[0074] (2) Processing points

[0075] 1) Spread

[0076] Spread the young leaves of Alpinia officinalis in a clean, ventilated and dry place with a thickness of about 10 cm, and turn them over gently every 2 hours. Spread them until they lose about 5% to 10% of water, lose their luster, and become soft to the touch.

[0077] 2) Finishing

[0078] Use steam to kill the green tea, the killing time is 30 seconds. You can also use a killing machine pot temperature of 120℃ to kill the green tea. The killing green tea should not clump when squeezed by hand, have a sweet taste, and no burnt smell, green leaf smell or fishy smell.

[0079] 3) Rolling

[0080] The tea is rolled more than twice with a tea rolling machine, usually for 5 to 8 minutes, which can be extended as needed. It is best to roll the tea until it becomes a natural strip without damaging the buds and leaves, and with a slight amount of tea juice on the surface to protect the color.

[0081] 4) Stir-fry

[0082] After kneading, use a tea frying machine to tumble fry the tea at a temperature of 220°C for 2 minutes.

[0083] 5) Drying

[0084] After tumbling, use a dryer to dry the mixture to a moisture content of ≤10%.

[0085] 6) Titian

[0086] Use a dryer to extract the fragrance and reach a moisture content of ≤7%.

[0087] The contents of moisture, total ash, water extract, free amino acids, tea polyphenols, total flavonoids, theaflavins and thearubigins of the loose tea of ​​Zingiber officinale in Example 1, the compressed tea of ​​Zingiber officinale in Example 1 and the tea prepared in Comparative Examples 1 to 3 were investigated. The specific investigation method is as follows:

[0088] ① Determination of moisture content: Use the 105℃±2℃ constant weight method (first method) in GB / T 8304-2013 "Determination of moisture content in tea".

[0089] ② Determination of total ash content: adopt the first method in GB 5009.4-2016 "National Food Safety Standard - Determination of Ash in Food".

[0090] ③ Determination of water extract content: Determine using the full amount method in GB / T 8305-2013 “Determination of tea water extract”.

[0091] ④ Determination of free amino acid content: Determination was carried out using the ninhydrin colorimetric method specified in GB / T 8314-2013 “Determination of the total amount of free amino acids in tea”.

[0092] ⑤ Determination of tea polyphenols content: The Folin phenol colorimetric method in GB / T 8313-2018 "Determination method for tea polyphenols and catechins in tea" was used for determination.

[0093] ⑥Determination of total flavonoids content: determined by spectrophotometry.

[0094] ⑦ Determination of theaflavin and thearubigin content: The system colorimetric method was used. The survey results are shown in Table 1.

[0095] Table 1 Comparison of ingredients of tea leaves prepared in Example 1 and Comparative Examples 1 to 4

[0096]

[0097] As can be seen from Table 1, the theaflavins content of the Alpinia galanga loose tea and Alpinia galanga compressed tea is high, and the tea polyphenols content and total flavonoids content in the tea are reduced to a certain extent. Therefore, the bitterness and sweetness can be reduced, and the taste of the tea can be improved. The tea soup is golden in color and sweet in taste. The aftertaste after entering the throat is also much lighter, and the taste is easier for the public to accept. It can also avoid the irritation of the stomach and intestines by excessively high concentrations of tea polyphenols, and retain a certain amount of tea polyphenols to provide the body with appropriate nutrients.

[0098] Comparative Example 4

[0099] Preparation technology of unshaken Ligustrum lucidum leaf tea

[0100] The process flow is: picking → indoor withering → outdoor withering → screening → indoor withering → drying → steaming → pressing → drying.

[0101] ① Tea picking: Collect 20 to 30 kilograms of fresh leaves. Figure 1 On sunny days, after the dew has dried, pick and remove the tender leaves for making green tea. The containers and transportation vehicles for holding the fresh leaves must be well ventilated, avoid squeezing and long-term stacking, avoid exposure to sunlight, and avoid the fresh leaves from being worn and turned red.

[0102] ② Indoor withering: Indoor withering trough temperature-controlled withering, the indoor temperature is 25-32°C, the stacking thickness of the leaves is 0.5-1.0cm, the withering is about 24 hours, and the moisture content of the obtained tea is about 60wt.%.

[0103] ③ Outdoor withering: When the sunlight is gentle, place the fresh leaves in the sun in the morning and evening when the sunlight is weak, and wither for about 3 hours. The moisture content of the obtained tea leaves is about 45wt.%.

[0104] ④ Combine two sieves into one sieve. The leaf thickness after combining two sieves is 1 to 2 cm.

[0105] ⑤ Indoor withering: The steps are the same as step ②, withering at 25-32°C for about 24 hours, and the moisture content of the obtained tea leaves is about 25wt.%.

[0106] ⑥ Drying: The tea leaves obtained in step ⑤ are slowly dried at 45±5℃ to obtain loose tea of ​​Ligustrum lucidum leaf, i.e. loose tea, also known as raw tea. Figure 2 As shown, the water content of the loose tea of ​​Ligusticum chuanxiong is about 5wt.%.

[0107] The tea soup color, aroma, taste and leaf bottom of the compressed tea of ​​Ligustrum lucidum in Example 1 and the tea leaves prepared in Comparative Examples 3 to 4 were investigated by 20 people with professional knowledge of food sensory analysis as judges. The results are shown in Table 2. Figure 2 and Figure 3 .

[0108] Table 2 Comparison of the sensation of tea leaves prepared in Example 1 and Comparative Examples 3-4

[0109] index Comparative Example 3 Comparative Example 4 Example 1 Soup color Orange-red, bright Light orange, bright Light orange, bright aroma Sweet Green Air Pure, strong taste Sweet to bitter Green flavor, strong sweetness Rich, moderately sweet Tea leaves Soft, broken, dark red Prickly hand, green in color Soft, green color

[0110] From Table 2, Figure 2 and Figure 3 It can be seen that the tea base of the shaken Ligustrum lucidum compressed tea is soft and green in color, and the tea soup is light orange-yellow and bright; the taste of Ligustrum lucidum green tea is too sweet, with a bitter aftertaste, and the taste is unacceptable; compared with green tea, the shaken Ligustrum lucidum compressed tea has a mellow taste and moderate sweetness; compared with the unshaken Ligustrum lucidum compressed tea, the shaken Ligustrum lucidum compressed tea has removed the green smell, has a stronger aroma, and has a softer leaf base.

[0111] Comparative Example 5

[0112] Production process of Alpinia officinalis black tea: Alpinia officinalis fresh leaves → withering → rolling → fermentation → drying

[0113] Withering: Indoor withering, fresh leaves of Alpinia zeylanicum are spread thinly to 2-3 cm, at an average temperature of 20°C, until the water content of fresh leaves reaches 62wt.%-63wt.%;

[0114] Kneading: no pressure for 5 minutes, light pressure for 10 minutes, heavy pressure for 10 minutes, light pressure for 5 minutes, heavy pressure for 10 minutes, light pressure for 5 minutes;

[0115] Fermentation: The temperature of the fermentation room is 28°C and the relative humidity is above 90%, and the fermentation is carried out for 4 hours;

[0116] Drying: Heat at 100°C until completely dry.

[0117] Comparative Example 6

[0118] Oolong tea production method:

[0119] ① Tea picking: Picking is done from 9:00 to 12:00 in the morning after the dew has dried, and from 13:30 to 16:00 in the afternoon. The weather should be sunny and the light should be sufficient to facilitate the sun-drying process. In terms of picking techniques, the "horse-riding picking" method is adopted. Hold the tea branches with the index finger and thumb, spread the leaves on both sides of the fingers, and gently break them upward. The utensils and transportation tools for fresh leaves must have good air permeability, avoid squeezing and long-term accumulation, avoid exposure to sunlight, and avoid excessive wilting of fresh leaves.

[0120] ② Sunlight withering: Fresh leaves picked from the tea garden should be spread out immediately to cool down to prevent the leaves from getting suffocated, and then spread out thinly and evenly at a temperature of about 25°C for 20 minutes. During the process, the leaves should be turned over frequently to ensure even sun drying, and they should be turned over 3 to 4 times.

[0121] ③ Indoor withering: Use natural withering method, ventilation on all sides, no direct exposure, at 20-25℃, the leaf thickness is 0.5-1.0cm.

[0122] ④ Shaking the tea leaves: It mainly includes two processes, shaking and standing, but it needs to be repeated and repeated for 6 to 9 times. The specific steps are: 1. The first and second shaking is to use both hands to shake the tea leaves on the bamboo sieve to revive the tea leaves. 2. The third to ninth shaking is to shake the bamboo sieve up and down, shaking the tea leaves in the sieve in a wave-like manner, causing the leaves to rub and collide with each other, and rub against the sieve wall and bottom, thereby destroying the leaf edge cells of the tea leaves and causing the tea leaves to turn red. At the same time, the standing time gradually increases with the number of shaking times.

[0123] ⑤ Fixing the green tea: After the green tea is made, put the green tea into the tea frame for fermentation for about 90 minutes. When the green tea emits a slight flower and fruit honey fragrance, it can be fixed. The specific steps are: the temperature in the pot is required to be around 220℃. When the green tea is poured into the bottom of the pot, it will make intermittent crackling sounds. After frying for 5 to 8 minutes, it can be taken out of the pot; after fixing the green tea, the leaves are bright green and wrinkled. There is no moisture when pinching the tea embryo with your hands, and the tea embryo is dry and does not stick to your hands. It smells fresh and fragrant.

[0124] ⑥Rolling: After the withering process is completed, when the tea embryo cools to 30℃, rolling can be carried out to make the leaves into strips or rolls. The rolling is done manually, and the rolling time is about 4 to 8 minutes each time, which can be adjusted according to the age of the leaves.

[0125] ⑦ Drying: Dry the Alpinia argyi Oolong tea at 80℃ for 90min.

[0126] The trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone and phlorizin of the samples obtained from different steps of the preparation of Example 2, Comparative Example 3, Comparative Example 5 and Comparative Example 6 were investigated, and the samples were sent to Youming Biological Co., Ltd. for testing. The contents of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone and phlorizin were determined by phenyl isothiocyanate pre-column derivatization reversed-phase high performance liquid chromatography. The test results are shown in Table 3;

[0127] The specific steps of phenyl isothiocyanate pre-column derivatization reversed-phase high performance liquid chromatography are as follows:

[0128] 1. Sample Pretreatment

[0129] Accurately weigh 0.25 g of leaf powder sample into a 5 mL glass test tube, add 2 mL of chromatographic grade methanol and seal the tube, oscillate and mix for 3 min, ultrasonically extract for 30 min, then centrifuge at 8000 rpm for 5 min, take the supernatant into a test tube, filter with a 0.45 μm organic filter membrane and set aside.

[0130] 2. Standard sample processing

[0131] Preparation of mixed standards: Accurately weigh 5 mg of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone and phlorizin standards into a 5 mL volumetric flask, add chromatographic grade methanol to make up to 5 mL, and prepare a mixed standard solution with a concentration of 1 mg / mL for each component. Subsequently, the above standard solutions were diluted with chromatographic grade methanol to 0.1 mg / mL, 0.05 mg / mL, 0.01 mg / mL, and 0.005 mg / mL mixed standard solutions.

[0132] Preparation of single standard: weigh about 1 mg of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone, and phlorizin standard into 5 mL glass test tubes, add 1 mL of chromatography grade methanol to prepare single standard solutions of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone, and phlorizin, respectively.

[0133] 3. Preparation of related reagents

[0134] Mobile phase A: 0.08% formic acid solution, obtained by adding 800 μL of chromatography-grade formic acid to 1000 mL of ultrapure water, followed by passing through a membrane and ultrasonically degassing before use.

[0135] Mobile phase B: 100% methanol, passed through the membrane and degassed by ultrasonic treatment before use.

[0136] 4.HPLC separation

[0137] Chromatographic column: C18 (4.6×250 mm, 5 μm), injection volume 20 μL, detection wavelength: 260 nm, flow rate: 0.8 mL / min, column temperature: 24°C, time: 35 min, gradient elution program see Table 3.

[0138] Table 3 Gradient elution program

[0139]

[0140]

[0141] 5. Precision experiment

[0142] The 1 mg / mL mixed standard was injected 5 times continuously, the peak area value was determined, and the RSD of the peak area was calculated. The results showed that the RSD of the peak area of ​​trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone, and phlorizin were 0.21%, 0.27%, 0.25%, 0.41%, and 0.35%, respectively, indicating that the instrument has good precision.

[0143] 6. Stability test

[0144] The sample solution was injected at 0h and 24h after preparation, and the peak area values ​​were recorded. The results showed that the RSDs of the peak areas of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone, and phlorizin were 0.53%, 0.61%, 0.39%, 0.54%, and 0.37%, respectively, indicating that the sample solution was stable within 24h.

[0145] 7. Repeatability Experiment

[0146] The same sample was weighed twice, and the sample solutions were prepared and injected. The peak areas were measured. The results showed that the average RSDs of the peak areas of trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone, and phlorizin were 3.2%, 1.3%, 2.9%, 3.5%, and 2.6%, respectively, indicating that this method has good repeatability.

[0147] 8. Standard Curve

[0148] The chromatogram of the mixed standard for preparing the standard curve is as follows: Figure 4 As shown, Figure 4 The peaks from left to right in the figure refer to: 3-hydroxyphlorizin, phlorizin, trilobatin, neohesperidin dihydrochalcone and phlorizin.

[0149] Single-label standard curve: The standard curve of trilobatin is Y=0.52155+423.70931*x, r 2 =0.99999, such as Figure 5 As shown; the standard curve of phlorizin is Y=0.08407+333.10553*x, r 2 =1, such as Figure 6 As shown; the standard curve of 3-hydroxyphlorizin is Y=-0.55402+321.93158*x, r 2 =0.99998, such as Figure 7 As shown; the standard curve of neohesperidin dihydrochalcone is Y=0.24727+296.00023*x, r 2 =1, such as Figure 8 As shown; the standard curve of phloretin is Y = 0.92358 + 444.48449 × x, r 2 =0.99998, such as Fig. 9 shown. Figure 6 to Figure 9 The horizontal axis is the concentration and the vertical axis is the peak area.

[0150] The trilobatin, phlorizin, 3-hydroxyphlorizin, neohesperidin dihydrochalcone and phlorizin of the samples obtained in different steps of the preparation methods of Example 1, Comparative Example 3, Comparative Example 5 and Comparative Example 6 were investigated, and the results are shown in Table 4.

[0151] Table 4 Dynamic changes in the contents of five sweet components of Alpinia officinalis leaves under different processing methods

[0152]

[0153]

[0154] As shown in Table 4, when processed into green tea, the first thing to do is to wither the green tea leaves, and the most sweet substances are retained, so the green tea product tastes too sweet. When making the Litsea cubeba pressed tea, the green tea leaves are withered without withering, and the resulting tea product retains the least sweet substances. This also solves the problem that the green tea products mainly produced by Litsea cubeba are too sweet and difficult for consumers to accept. It can be seen that if you want to extract sweeteners, you should wither the green tea leaves immediately after picking. If you want to process it into a tea product with a popular taste, you can consider making Litsea cubeba pressed tea.

[0155] A response surface experiment was conducted, and the quality of the compressed tea of ​​Ligustrum lucidum, tea boiling time, and tea stewing time were selected as independent variables. According to the response surface experimental design method, the sensory evaluation score was used as the response value, and a three-factor three-level response surface experimental design was carried out. The sensory evaluation score response surface factor level table 5 was used to optimize the optimal tea brewing process of Ligustrum lucidum compressed tea.

[0156] Assume that the amount of Ligustrum lucidum compressed tea is factor A, set the amount of 4g of Ligustrum lucidum compressed tea to -1, the amount of 5g of Ligustrum lucidum compressed tea to 0, and the amount of 6g of Ligustrum lucidum compressed tea to 1.

[0157] Let the brewing time be factor B, set the brewing time of 8 minutes to -1, the brewing time of 10 minutes to 0, and the brewing time of 12 minutes to 1.

[0158] Assume that the stewing time of tea is factor C, set the stewing time of 1 minute to -1, the stewing time of 2 minutes to 0, and the stewing time of 3 minutes to 1.

[0159] Table 5. Sensory evaluation score response surface factor level table

[0160]

[0161]

[0162] The specific grouping is detailed in Example 2 and Comparative Examples 10 to 18.

[0163] Example 2

[0164] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 6 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 2 min.

[0165] Comparative Example 10

[0166] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 4 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 2 min.

[0167] Comparative Example 11

[0168] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 2 min.

[0169] Comparative Example 12

[0170] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the boiling time is 8 min, and the stewing time is 2 min.

[0171] Comparative Example 13

[0172] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the boiling time is 8 min, and the stewing time is 2 min.

[0173] Comparative Example 14

[0174] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 2 min.

[0175] Comparative Example 15

[0176] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 12 min, and the tea stewing time is 2 min.

[0177] Comparative Example 16

[0178] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 1 min.

[0179] Comparative Example 17

[0180] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 2 min.

[0181] Comparative Example 18

[0182] The mass of the Ligustrum lucidum leaf compressed tea prepared in Example 1 is 5 g, the water is 1100 mL, the tea boiling time is 10 min, and the tea stewing time is 3 min.

[0183] Sensory evaluation test

[0184] 20 personnel with professional knowledge of food sensory analysis were selected as judges to conduct sensory evaluation on the teas of Example 2 and Comparative Examples 10 to 18, and scored according to the sensory evaluation standard for Ligustrum lucidum leaf compressed tea. After one group was completed, the mouth was rinsed with warm water and the next cup was tasted. The sensory evaluation standard for Ligustrum lucidum leaf compressed tea is shown in Table 6, and all scores are calculated by rounding off the average score.

[0185] Table 6 Sensory evaluation standards for Alpinia officinalis compressed tea

[0186]

[0187] The sensory scores of Example 2 and Comparative Examples 10 to 18 were investigated, and the specific response surface analysis results are shown in Table 7.

[0188] Table 7 Response surface analysis experimental results

[0189]

[0190]

[0191] As shown in Table 7, A0B0C0 has the highest sensory score of 85.6 points, that is, the mass of the compressed tea of ​​Alpinia zedoaria leaves and branches is 5g, the brewing time is 10min, and the stewing time is 2min.

[0192] The data in Table 7 are processed to obtain the variance results of each item in the regression equation. The results are shown in Table 8.

[0193] Table 8 Variance of each term in the regression equation

[0194]

[0195] Note: “*” indicates a significant effect on the results (P<0.05); “**” indicates an extremely significant effect on the results (P<0.01).

[0196] It can be seen from Table 8 that the P value of the established model is significant < 0.01, and the P value of the lack-of-fit term is not significant, indicating that the model has high reliability.

[0197] Based on the above response surface model analysis, the Design-Expert8.0.6 software was used for optimization, and the optimal brewing process of Ligustrum lucidum compressed tea was obtained as follows: Ligustrum lucidum compressed tea mass 5.78g, tea boiling time 10.00min, tea stewing time 1.76min, and the sensory evaluation prediction value of Ligustrum lucidum compressed tea was 87.5 points. For the convenience of actual operation, the tea boiling process was revised to 1100mL of water mass, 6.00g of Ligustrum lucidum compressed tea, 10.00min of tea boiling time, and 2.00min of tea stewing time. A verification test was carried out with this process flow, and the average sensory score of Ligustrum lucidum compressed tea was 87.3 points. The results showed that the fitting effect of this method was good and it had practical value.

[0198] Example 3

[0199] The steps are the same as those in Example 1, except that the shaking time is 30 min.

[0200] Comparative Example 19

[0201] The steps are the same as those in Example 1, except that the shaking time is 60 min.

[0202] The taste and ingredients of tea leaves of Example 1, Example 3, Comparative Example 4 and Comparative Example 19 were investigated. The method for detecting the ingredients of tea leaves has been described in detail in the aforementioned embodiment part and will not be repeated here.

[0203] Sensory evaluation test

[0204] 20 persons with professional knowledge of food sensory analysis were selected as judges to conduct sensory evaluation on the teas of Example 1, Example 3, Comparative Example 4 and Comparative Example 19. The sensory evaluation criteria are shown in Table 9, and all scores were calculated by rounding off the average score.

[0205] The test results of tea components and sensory evaluation results are shown in Table 10.

[0206] Table 9 Sensory evaluation standards

[0207] Evaluation score Sensory evaluation standards 0~73 points The smell is obvious and the taste is bitter 74-79 points The green smell is more obvious and the taste is bitter 80-84 points The sweet aroma is slightly less obvious, and the taste is slightly bitter 85-89 points Sweet aroma, slightly astringent taste 90-100 points The sweet aroma is more obvious, and the taste is mellow and mild

[0208] Table 10 Research on shaking green tea process

[0209]

[0210]

[0211] Note: No shaking is for comparative example 4, shaking time is 30 min for example 3, shaking time is 45 min for example 1, and shaking time is 60 min for comparative example 19.

[0212] From the data in Table 9, it can be seen that the un-shaken Ligustrum lucidum pressed tea has a stronger smell and a bitter taste, while the Ligustrum lucidum pressed tea that has been shaken for 45 minutes has a more obvious sweet aroma and a mellow and mild taste.

[0213] In summary, when the present invention prepares the compressed tea of ​​Ligustrum lucidum, the process of shaking green is creatively added during the withering process, which improves the types and contents of aroma and biochemical components in the compressed tea of ​​Ligustrum lucidum, and improves the sensory quality of the compressed tea of ​​Ligustrum lucidum; the method of the present invention can be used to process compressed tea products with excellent comprehensive quality in appearance, fragrance, taste and shape. When Ligustrum lucidum is prepared into green tea by the prior art, the fresh leaves of Ligustrum lucidum are directly subjected to the withering treatment, and the green tea finished product finally obtained has a high content of sweet substances retained, mainly sweet substances such as trifoliatin, phlorizin, neohesperidin dihydrochalcone, phlorizin, 3-hydroxyphlorizin, etc., resulting in a particularly sweet taste, which is difficult for many consumers to accept, and the content of tannin in the tea polyphenols in green tea is also relatively high, so the aftertaste is also relatively bitter, so Ligustrum lucidum green tea is not popular with consumers. The invention uses withering and drying to obtain compressed tea with less sweet substances and relatively low contents of tea polyphenol tannins, and combines with steaming and low-temperature drying during cake pressing to finally obtain a finished product with moderate sweetness, reduced bitterness, light aftertaste and richer aroma. The tea soup meets the needs of the general public, and the acceptance of the Ligusticum chuanxiong compressed tea product among consumers is improved.

[0214] Moreover, the preparation method provided by the present invention uses fresh leaves of Ligustrum lucidum as raw materials, not limited to tender leaves, and realizes the comprehensive utilization of Ligustrum lucidum leaf resources. The Ligustrum lucidum pressed tea prepared by the present invention is easy to brew, has a golden soup color, and tastes sweet. Compared with traditional craft tea, the acceptance of Ligustrum lucidum pressed tea among consumers is greatly improved, and the market scope is greatly improved.

[0215] Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing Ligustrum lucidum leaf compressed tea, characterized in that: It consists of the following steps: The fresh leaves of Ligustrum lucidum are sequentially subjected to first withering, shaking, second withering, sieving, third withering and drying to obtain Ligustrum lucidum loose tea; Sequentially steaming, pressing and drying the Ligustrum lucidum leaf loose tea to obtain Ligustrum lucidum leaf compressed tea; The shaking time is 35 to 50 minutes; The first withering is a first indoor withering; the temperature of the first withering is 25-32° C.; the water content of the leaves obtained by the first withering is 60wt.%-65wt.%; The second withering is outdoor withering; the outdoor withering comprises: placing the leaves after shaking under the sun for 3 hours when the sunlight is weak; the water content of the leaves obtained by the second withering is 42wt.% to 47wt.%; The third withering is the second indoor withering; the temperature of the third withering is 25-32°C; the water content of the leaves obtained by the third withering is 22wt.%-27wt.%; The fresh leaves of the Litsea cubeba include tender leaves of the Litsea cubeba and / or slightly coarse, old and large leaves of the Litsea cubeba; The drying temperature is 45±5°C; the water content of the loose tea of ​​Ligustrum lucidum is 5wt.%; After the second withering, the process further includes screening; after the screening, the thickness of the leaves is 1 to 2 cm; The tea steaming time is 2 minutes; the drying temperature is 40-50° C.; the water content of the dried tea obtained by drying is ≤5wt.%.

2. A compressed tea made from the leaves of Alpinia zedoariae by the method of claim 1, characterized in that: The content of trilobatin in the Ligusticum chuanxiong compressed tea is 64.631-70.351 mg / g, the content of phlorizin is 4.812-6.072 mg / g, the content of 3-hydroxyphlorizin is 1.413-1.653 mg / g, the content of neohesperidin dihydrochalcone is 0.021-0.161 mg / g, and the content of phlorizin is 1.641-3.401 mg / g.

3. The pressed tea of ​​Ligusticum chuanxiong leaves according to claim 2, characterized in that: The moisture content of the compressed tea of ​​Pinus armeniaca leaves is 3-5%, the total ash content is 4.5-6.5%, the water extract content is 36-38.5%, the free amino acid content is 3-4%, the total flavonoids content is 6.5-8%, the tea polyphenols content is 20-24%, theaflavins content is 0.6-0.8%, and thearubigins content is 7.5-9.5%.

4. A method for preparing a tea beverage made from Ligustrum lucidum leaves, wherein the Ligustrum lucidum leaves compressed tea is obtained by the method of claim 1, characterized in that: The preparation method comprises the following steps: mixing the compressed tea of ​​Ligustrum lucidum leaf with water to boil the tea and to steam the tea; The mass volume ratio of the Ligustrum lucidum leaf compressed tea to water is 6g:1100mL; the time for boiling the tea is 10min; and the time for steaming the tea is 2min.

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