CN107751436B - Vietnam ampelopsis stem tea fermented tea and preparation method thereof - Google Patents

Abstract

The invention discloses a fermented tea of Vietnam army stem tea, which takes one bud of tender leaves of the Vietnam army stem tea and one leaf of tender leaves of the Vietnam army stem tea as raw materials and is a fully fermented tea. The preparation process flow comprises the steps of fresh leaf picking, withering leaf preparation, slicing, rolling, fermentation, gross fire primary drying, full fire and aroma raising. The dry tea of the fermented tea of the Vietnamese ampelopsis stem prepared by the invention is dark brown and black, and the tea is tightly tied; the tea brewed by boiling water is orange and bright in liquor color, fresh and sweet in taste, free of bitter and astringent feeling, unique in flower fragrance, 30-35.8% of water extract, 14.2-22.8% of tea polyphenol, 1.8-3.2% of flavone and 1.5-2.0% of amino acid, the utilization rate of nutrient components in the raw materials is remarkably improved, and a new direction is provided for development and utilization of the tea embracing the stems in Vietnam.

Description

Vietnam ampelopsis stem tea fermented tea and preparation method thereof

Technical Field

The invention relates to the field of production and processing of fermented tea, in particular to fermented tea prepared by taking Vietnamese ampelopsis stem tea leaves as a raw material and a preparation method thereof.

Background

Vietnam tea (Camellia plexicaulis) belongs to ancient tea group plant of Camellia in Theaceae, is native to Liangshan province in North Vietnam, and currently has three red, yellow and white varieties. Blooming in four seasons, huge leaves and unique flower type. The red Vietnam stem holding tea is also called begonia tea and four-season stem holding tea, and is a four-season good seed for viewing flowers and leaves. The special meat is pink red, the petals are thick and are similar to hard flowers, the flower is shaped like a Chinese flowering crabapple, a golden stamen, a single petal and a medium flower, and the fresh, elegant and bright feeling is brought to people when the flower is opened; the leaves are wide and similar to loquat leaves, and are bright, and the base of the leaves embraces the stem, so the tea is named as stem embracing tea; the pot can be potted in the flowering period in four seasons, is very shade-resistant, can try indoor cultivation, and has high ornamental value.

The introduction of the Vietnam hugging tea in China in recent years is mainly to carry out research on garden value, cultivation, breeding, physiological ecology and the like. Yan Dingyu and the like show that the tea polyphenol content of the tender leaves of several camellia species such as Vietnam stem-clasping tea and the like is 30.44% > 11.89% > 8.62% > 7.23% in sequence through analysis of the tea polyphenol content of the leaves of the Vietnam stem-clasping tea and the like, and the Yan Dingyu and the like are in the same camellia genus, but the tea polyphenol content of the Vietnam stem-clasping tea is obviously higher than that of other camellia species, and even higher than that of a plurality of high-quality green teas (25.22%). Tea polyphenol is also called tea tannin and tea tannin, comprises flavanols, anthocyanin, flavonoid, flavonol, phenolic acid and the like, is not only a natural nontoxic antioxidant, but also an ideal natural medicine, has biological activities of eliminating free radicals, resisting oxidation and the like, has good effects in the aspects of delaying senility, resisting oxidation, inhibiting bacteria and killing bacteria, resisting viruses, preventing and resisting cancers and inhibiting tumors, preventing and treating cardiovascular diseases, beautifying and protecting skin, enhancing immunity and the like, and is widely applied to the fields of food, cosmetics, medical care and the like. The tea leaves with the stems of the army, which are rich in tea polyphenols, lays a good material foundation for developing the tea leaves with the stems of the army of Vietnam into various tea products with health care functions for human bodies.

However, at present, the Vietnam ampelopsis tea is only used for cultivating indoor leaf-watching plants and ornamental flowers, and no research institute for related tea making exists. The reason is analyzed, and the following problems mainly exist: (1) since the introduction of the Vietnam stem-embracing tea, research is mainly focused on the aspect of propagation and cultivation, at present, the research related to digging the processing potential is less, the tender leaves and buds of the Vietnam stem-embracing tea are made into green tea according to the green tea process deactivating enzyme, and the finished product has obvious bitter taste and poor taste due to higher tea polyphenol content; (2) the tea leaves in the south of Vietnam have thick and leathery quality, are difficult to dehydrate during withering, and have strict requirements on conditions of withering temperature and humidity compared with common tea. (3) The leaves of the Vietnam stem-holding tea are much larger than the common tea, the rolling is not easy to form, the cells are not damaged uniformly, the strips after the rolling are loose, the fermentation is not uniform, the volume of the dry tea is expanded, and the tea is inconvenient to brew due to the thick strips.

Disclosure of Invention

Aiming at the problems of high phenol content, bitter taste, thick leaf, difficult water leakage, difficult forming by rolling, easy uneven fermentation and the like of the leaves of the vietnam stem-clasping tea, the invention provides the vietnam stem-clasping tea fermented tea and the preparation method thereof, the tender leaves of the vietnam stem-clasping tea are selected and subjected to withering, slicing, rolling, fermentation, primary drying by gross fire, spreading and drying in the air, full fire and fragrance improvement to obtain the vietnam stem-clasping tea fermented tea, the prepared product is red brown and dark, tight in strip, and has bright orange yellow and bright soup color after being brewed with boiling water, fresh and sweet taste, no bitter and unique flower fragrance, the water extract content is 30-35.8%, the tea polyphenol content is 14.2-22.8%, the flavone content is 1.8-3.2%, and the amino acid content is 1.5-2.0%. Obviously improves the utilization rate of the nutrient components in the raw materials.

The invention adopts the following technical scheme to solve the technical problems:

a fermented tea of Vietnam stem-holding tea is prepared from tender leaves of Vietnam stem-holding tea, including one bud, one leaf and two leaves, as raw materials.

The preparation method of the Vietnamese ampelopsis stem tea fermented tea comprises the following process steps:

(1) picking fresh leaves: picking tender leaves of the tea leaves of the Vietnam army stems as raw materials;

(2) preparing withered leaves: the tender leaves picked in the step (1) are thinly spread and withered;

(3) slicing: slicing the withered leaves obtained in the step (2);

(4) rolling: rolling the slices obtained in the step (3);

(5) fermentation: fermenting the rolled leaves obtained in the step (4);

(6) primary baking with gross fire: drying the fermented leaves obtained in the step (5) at the temperature of 100-110 ℃ for 10-15 min;

(7) spreading for cooling: spreading and cooling the primary dried leaves obtained in the step (6) to room temperature;

(8) and (3) full fire: drying the tea leaves obtained in the step (7) in a dryer at the temperature of 60-85 ℃ for 1-1.5 h to obtain crude Vietnam stem holding tea;

(9) and (3) fragrance extraction: and (4) carrying out aroma improvement on the crude Vietnam army stem tea obtained in the step (8) to obtain finished Vietnam army stem tea.

The tender leaves of the Vietnamese ampelopsis stem tea in the step (1) are tender leaves with one bud and one leaf and two leaves.

And (3) performing thin withering, wherein the thickness of the thin withering is 0.5-1.0 cm, the withering temperature is 28-33 ℃, the relative humidity RH is 60-70%, and the water content of the withered leaves is controlled at 62-65% after the withering is finished.

The slice in the step (3) is a sheet with the size of 8mm multiplied by 15 mm.

The rolling environment condition in the step (4) requires low temperature and high humidity, namely an environment with the temperature of 20-24 ℃ and the humidity of 85-95%; the rolling process comprises the following steps: air kneading is carried out for 15-35 min without pressure, pressurization is carried out for 20-30 min, decompression is carried out for 3-5 min, pressurization is carried out for 10-25 min, and decompression is carried out for 3-5 min.

In the fermentation in the step (5), the fermentation temperature is 28-33 ℃, the humidity is more than 95%, the ventilation and oxygen introduction time is set to be 40-60 min/time, the fermentation is carried out for 3-6 hours, and the fermentation can be finished when the grass smell disappears and the faint scent is initially shown;

and (3) carrying out primary drying on the rough fire in the step (6) in a dryer, setting the temperature to be 100-110 ℃, thinly spreading the fermented leaves to be 0.5-0.8 cm, feeding the tea after the dryer reaches the set temperature, drying for 10-15 min, and controlling the moisture of the primary dried leaves to be 20-25%.

And (7) spreading for cooling, wherein the thickness of the spread tea is 2-3 cm.

And (3) carrying out aroma extraction in an aroma extracting machine at the temperature of 110-120 ℃, feeding tea after the aroma extracting machine reaches the set temperature, drying for 20-30 min, spreading for cooling for 40min, and extracting aroma for 10-15 min to obtain the finished tea of the Vietnam bayberry stem tea.

The invention has the advantages that:

the fermented dried tea prepared by the method of the invention has dark brown and smooth tea red and tight rope; the tea soup after being brewed by boiling water is orange and bright, has fresh and sweet taste, no bitter feeling and unique flower fragrance, and has the water extract content of 30-35.8 percent, the tea polyphenol content of 14.2-22.8 percent, the flavone content of 1.8-3.2 percent and the amino acid content of 1.5-2.0 percent. Obviously improves the utilization rate of nutrient components in the raw materials and provides a new direction for the development and utilization of the Vietnam hugging tea.

Detailed Description

The following examples are given to illustrate specific embodiments of the present invention, but should not be construed to limit the scope of the claims.

Example 1

A fermented tea of Vietnam stem-holding tea is prepared from tender leaves of Vietnam stem-holding tea, including one bud, one leaf and two leaves, as raw materials. The preparation process flow is as follows: picking fresh leaves, preparing withered leaves, slicing, rolling, fermenting, primarily drying by gross fire, sufficiently firing, extracting fragrance and storing finished products. The method comprises the following specific steps:

1. picking fresh leaves: the tender leaves of the Vietnam ampelopsis tea are picked, one bud is picked, the other leaves are picked as raw materials for standby, the content of effective components such as phenolic substances of old leaves is low, the preparation effect of the fermented tea is not good, and insect buds, diseased buds and damaged buds are avoided.

2. Preparing withered leaves: and (3) spreading the tender leaves picked in the step (1) in a bamboo skin drying sieve to dissipate water, wherein the tender leaves are required to be spread thinly during withering because the water loss of the thick and leathery tea leaves is difficult, the spreading thickness is 0.8m, the withering temperature is 29 ℃, the relative humidity is RH60%, and the water content of the withered leaves is controlled to be 62% after the withering is finished.

3. Slicing: and (3) slicing the withered leaves of the tea leaves of the Vietnam army stem obtained in the step (2), and cutting the leaves into about 8mmX15mm slices.

4. Rolling: and (3) rolling the slices obtained in the step (3), wherein the rolling can be carried out manually or by using a rolling machine, and the principle of light-heavy-light rolling is mastered. The proper twisting mark is that the strip rope is tightly coiled and is tightly held by hands, and the tea juice overflows without dripping. The rolling environment condition requires low temperature and high humidity, namely an environment with the temperature of 20 ℃ and the humidity of 85 percent; the rolling process comprises the following steps: air-kneading without pressure for 15min, pressurizing for 30min, decompressing for 5min, pressurizing for 10min, and decompressing for 3 min.

5. Fermentation: and (4) stacking or transferring the rolled leaves in the step (4) to a fermentation machine capable of controlling temperature, humidity and oxygen, fermenting at the fermentation temperature of 30 ℃, the humidity of more than 95 percent, setting the air and oxygen exchange time for 60 min/time, fermenting for 5 hours, and finishing fermentation when the grass smell disappears and the faint scent is displayed.

6. Primary baking with gross fire: setting the temperature of a dryer at 105 ℃, thinning the fermented leaves obtained in the step 5 to be 0.6cm, feeding the tea after the dryer reaches the set temperature, drying for 12min, and controlling the moisture of the primarily dried leaves to be 20%.

7. Spreading for cooling: 6, spreading the primarily dried leaves obtained in the step 6 to cool to room temperature, and spreading the tea to a thickness of about 2.5 cm;

8. and (3) full fire: and (4) drying the tea leaves obtained in the step (7) in a dryer with full fire, setting the temperature of the dryer at 70 ℃, and drying for 1.2h to obtain the crude Vietnam baotian tea.

9. And (3) fragrance extraction: and (4) extracting aroma of the crude tea of the Vietnam stem-embracing tea dried in the step (8), setting the temperature of an aroma extracting machine to be 110 ℃, drying the tea for 25min after the aroma extracting machine reaches the set temperature, spreading for cooling for 40min, setting the temperature of the aroma extracting machine to be 120 ℃, and extracting aroma for 10min to obtain the finished product tea of the Vietnam stem-embracing tea.

The fermented tea of the vietnamese ampelopsis stem prepared by the embodiment is stored in a sealed manner under the conditions of light resistance, drying and no peculiar smell. The product is characterized in that: the dry tea is dark brown, firm, orange and bright in soup color, fresh and sweet in taste, free of bitter and astringent feeling and unique in flower fragrance. 30% of water extract, 18.8% of tea polyphenol, 1.8% of flavone and 1.5% of amino acid.

Example 2

A fermented tea of Vietnam stem-holding tea is prepared from tender leaves of Vietnam stem-holding tea, including one bud, one leaf and two leaves, as raw materials. The preparation process flow is as follows: picking fresh leaves, preparing withered leaves, slicing, rolling, fermenting, primarily drying by gross fire, sufficiently firing, extracting fragrance and storing finished products. The method comprises the following specific steps:

1. picking fresh leaves: the tender leaves of the Vietnam ampelopsis tea are picked, one bud is picked, the other leaves are picked as raw materials for standby, the content of effective components such as phenolic substances of old leaves is low, the preparation effect of the fermented tea is not good, and insect buds, diseased buds and damaged buds are avoided.

2. Preparing withered leaves: and (3) spreading the tender leaves picked in the step (1) in a bamboo skin drying sieve to dissipate water, wherein the tender leaves are required to be spread thinly during withering because the water loss of the thick and leathery tea leaves is difficult, the spreading thickness is 0.5m, the withering temperature is 31 ℃, the relative humidity is RH 66%, and the water content of the withered leaves is controlled to be 64% after the withering is finished.

3. Slicing: and (3) slicing the withered leaves of the tea leaves of the Vietnam army stem obtained in the step (2), and cutting the leaves into about 8mmX15mm slices.

4. Rolling: and (3) rolling the slices obtained in the step (3), wherein the rolling can be carried out manually or by using a rolling machine, and the principle of light-heavy-light rolling is mastered. The proper twisting mark is that the strip rope is tightly coiled and is tightly held by hands, and the tea juice overflows without dripping. The rolling environment condition requires low temperature and high humidity, namely an environment with the temperature of 22 ℃ and the humidity of 90 percent; the rolling process comprises the following steps: air kneading without pressure for 25min, pressurizing for 20min, decompressing for 3min, pressurizing for 20min, and decompressing for 4 min.

5. Fermentation: and (4) stacking or transferring the rolled leaves in the step (4) to a fermentation machine capable of controlling temperature, humidity and oxygen, fermenting at the fermentation temperature of 28 ℃, the humidity of more than 95 percent, setting the time of air exchange and oxygen exchange for 50 min/time, fermenting for 6 hours, and finishing fermentation when the grass smell disappears and the faint scent is displayed.

6. Primary baking with gross fire: setting the temperature of the dryer at 100 ℃, wherein the thickness of the fermented leaves obtained in the step 5 is 0.5cm, feeding the tea after the temperature of the dryer reaches the set temperature, drying for 10min, and controlling the moisture of the primary dried leaves at 25%.

7. Spreading for cooling: 6, spreading the primarily dried leaves obtained in the step 6 to cool to room temperature, and spreading the tea to be about 3cm thick;

8. and (3) full fire: and (7) drying the tea leaves obtained in the step (7) in a drier with full fire, setting the temperature of the drier at 60 ℃, and drying for 1.5h to obtain the crude Vietnam hugging tea.

9. And (3) fragrance extraction: and (4) extracting aroma of the crude tea of the Vietnam stem-embracing tea dried in the step (8), setting the temperature of an aroma extracting machine to be 110 ℃, drying the tea for 30min after the aroma extracting machine reaches the set temperature, spreading for cooling for 40min, setting the temperature of the aroma extracting machine to be 120 ℃, and extracting aroma for 12min to obtain the finished product tea of the Vietnam stem-embracing tea.

The fermented tea of the vietnamese ampelopsis stem prepared by the embodiment is stored in a sealed manner under the conditions of light resistance, drying and no peculiar smell. The product is characterized in that: the dry tea is dark brown, firm, orange and bright in soup color, fresh and sweet in taste, free of bitter and astringent feeling and unique in flower fragrance. The content of water extract is 33.2%, the content of tea polyphenol is 14.2%, the content of flavone is 2.2%, and the content of amino acid is 1.9%.

Example 3:

a fermented tea of Vietnam stem-holding tea is prepared from tender leaves of Vietnam stem-holding tea, including one bud, one leaf and two leaves, as raw materials. The preparation process flow is as follows: picking fresh leaves, preparing withered leaves, slicing, rolling, fermenting, primarily drying by gross fire, sufficiently firing, extracting fragrance and storing finished products. The method comprises the following specific steps:

1. picking fresh leaves: the tender leaves of the Vietnam ampelopsis tea are picked, one bud is picked, the other leaves are picked as raw materials for standby, the content of effective components such as phenolic substances of old leaves is low, the preparation effect of the fermented tea is not good, and insect buds, diseased buds and damaged buds are avoided.

2. Preparing withered leaves: the tender leaves picked in the step 1 are spread in a bamboo skin drying sieve to lose water, and because the thick and leathery tea leaves with stems are difficult to lose water, the tender leaves need to be spread thinly during withering, the spreading thickness is 1.0cm, the withering temperature is 33 ℃, the relative humidity is RH 70%, and the water content of the withered leaves is controlled to be 65% after the withering is finished.

3. Slicing: and (3) slicing the withered leaves of the tea leaves of the Vietnam army stem obtained in the step (2), and cutting the leaves into about 8mmX15mm slices.

4. Rolling: and (3) rolling the slices obtained in the step (3), wherein the rolling can be carried out manually or by using a rolling machine, and the principle of light-heavy-light rolling is mastered. The proper twisting mark is that the strip rope is tightly coiled and is tightly held by hands, and the tea juice overflows without dripping. The rolling environment condition requires low temperature and high humidity, namely an environment with the temperature of 24 ℃ and the humidity of 95 percent; the rolling process comprises the following steps: air-kneading without pressure for 35min, pressurizing for 25min, decompressing for 4min, pressurizing for 25min, and decompressing for 5 min.

5. Fermentation: and (4) stacking or transferring the rolled leaves in the step (4) to a fermentation machine capable of controlling temperature, humidity and oxygen, fermenting at the fermentation temperature of 33 ℃, the humidity of more than 95 percent, setting the air and oxygen exchange time of 40 min/time, fermenting for 3 hours, and finishing fermentation when the grass smell disappears and the faint scent is displayed.

6. Primary baking with gross fire: setting the temperature of the dryer at 110 ℃, thinning the fermented leaves obtained in the step 5 to be 0.8cm in thickness, feeding the tea after the temperature of the dryer reaches the set temperature, drying for 15min, and controlling the moisture of the primarily dried leaves to be 22%.

7. Spreading for cooling: 6, spreading the primarily dried leaves obtained in the step 6 to cool to room temperature, and spreading the tea to a thickness of about 2.0 cm;

8. and (3) full fire: and (4) drying the tea leaves obtained in the step (7) in a dryer with full fire, wherein the temperature of the dryer is set to be 85 ℃, and the drying time is 1.0h, so that the crude Vietnam stem tea is obtained.

9. And (3) fragrance extraction: and (4) extracting aroma of the crude tea of the Vietnam stem-embracing tea dried in the step (8), setting the temperature of an aroma extracting machine to be 115 ℃, drying the tea for 20min after the aroma extracting machine reaches the set temperature, spreading for cooling for 40min, setting the temperature of the aroma extracting machine to be 120 ℃, and extracting aroma for 10min to obtain the finished product tea of the Vietnam stem-embracing tea.

The fermented tea of the vietnamese ampelopsis stem prepared by the embodiment is stored in a sealed manner under the conditions of light resistance, drying and no peculiar smell. The product is characterized in that: the dry tea is dark brown, firm, orange and bright in soup color, fresh and sweet in taste, free of bitter and astringent feeling and unique in flower fragrance. 35.8 percent of water extract, 22.8 percent of tea polyphenol, 3.2 percent of flavone and 2.0 percent of amino acid.

Claims (2)

1. A preparation method of the Vietnamese ampelopsis stem tea fermented tea is characterized by comprising the following process steps:

(1) picking fresh leaves: picking tender leaves of the tea leaves of the Vietnam army stems as raw materials;

(2) preparing withered leaves: the tender leaves picked in the step (1) are thinly spread and withered;

(3) slicing: slicing the withered leaves obtained in the step (2);

(4) rolling: rolling the slices obtained in the step (3);

(5) fermentation: fermenting the rolled leaves obtained in the step (4);

(6) primary baking with gross fire: drying the fermented leaves obtained in the step (5) at the temperature of 100-110 ℃ for 10-15 min;

(7) spreading for cooling: spreading and cooling the primary dried leaves obtained in the step (6) to room temperature;

(8) and (3) full fire: drying the tea leaves obtained in the step (7) in a dryer at the temperature of 60-85 ℃ for 1-1.5 h to obtain crude Vietnam stem holding tea;

(9) and (3) fragrance extraction: the raw tea of the Vietnam ampelopsis stem holding tea obtained in the step (8) is subjected to aroma improvement to obtain finished Vietnam ampelopsis stem holding tea;

the tender leaves of the Vietnamese ampelopsis stem tea in the step (1) are tender leaves with one bud and one leaf and two leaves;

the withering is carried out in a thin spreading mode in the step (2), the spreading thickness is 0.5-1.0 cm, the withering temperature is 28-33 ℃, the relative humidity RH is 60% -70%, and the water content of withered leaves is controlled to be 62% -65% after the withering is finished;

the slice in the step (3) is a sheet with the size of 8mm multiplied by 15 mm;

the rolling environment condition in the step (4) requires low temperature and high humidity, namely an environment with the temperature of 20-24 ℃ and the humidity of 85-95%; the rolling process comprises the following steps: air kneading without pressing for 15-35 min, pressurizing for 20-30 min, decompressing for 3-5 min, pressurizing for 10-25 min, decompressing for 3-5 min;

in the fermentation in the step (5), the fermentation temperature is 28-33 ℃, the humidity is more than 95%, the ventilation and oxygen introduction time is set to be 40-60 min/time, the fermentation is carried out for 3-6 hours, and the fermentation can be finished when the grass smell disappears and the faint scent is initially shown;

the gross fire primary drying in the step (6) is carried out in a dryer, the temperature is set to be 100-110 ℃, the thickness of the spread fermented leaves is 0.5-0.8 cm, the tea is fed after the dryer reaches the set temperature, the drying time is 10-15 min, and the moisture of the primary dried leaves is controlled to be 20-25%;

and (3) carrying out aroma extraction in an aroma extracting machine at the temperature of 110-120 ℃, feeding tea after the aroma extracting machine reaches the set temperature, drying for 20-30 min, spreading for cooling for 40min, and extracting aroma for 10-15 min to obtain the finished tea of the Vietnam bayberry stem tea.

2. The preparation method of the fermented tea of the vietnamese ampelopsis stem tea as claimed in claim 1, wherein the spreading and cooling in the step (7) are carried out, and the thickness of the spread tea is 2 cm-3 cm.