CN114158628A

CN114158628A - Preparation method of camellia nitidissima tea

Info

Publication number: CN114158628A
Application number: CN202111564195.9A
Authority: CN
Inventors: 谢阳姣; 唐国翠; 何秋梅; 姚涵雅; 李耀燕; 闫国跃; 高慧; 陆文萍; 莫创宇
Original assignee: Dongxing Tianzhilin Agricultural Technology Co ltd; Guangxi University of Chinese Medicine
Current assignee: Dongxing Tianzhilin Agricultural Technology Co ltd; Guangxi University of Chinese Medicine
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-03-11

Abstract

The invention belongs to the technical field of tea preparation, and particularly relates to a preparation method of camellia nitidissima tea. The invention provides a preparation method of camellia nitidissima tea, which takes fresh camellia nitidissima leaves as raw materials, leads the fresh camellia nitidissima leaves to be heated more uniformly in the de-enzyming process through a mode of shredding firstly and de-enzyming, is easy to emit green odor, promotes the formation of good fragrance, better inhibits the enzymatic oxidation of tea polyphenol in the fresh leaves, and improves the sensory quality of the camellia nitidissima tea. Meanwhile, the combined fixation mode of microwave fixation and steaming is adopted, so that the conditions of tea frying, incomplete fixation and non-uniform fixation caused by the conventional fixation mode can be avoided; the steaming is carried out after microwave enzyme deactivation, so that the leather leaves of the golden camellia can be softer, the subsequent rolling of juice is facilitated, the cell walls of the leaves are better damaged, and the separation of beneficial components in the tea leaves is promoted.

Description

Preparation method of camellia nitidissima tea

Technical Field

The invention belongs to the technical field of tea preparation, and particularly relates to a preparation method of camellia nitidissima tea.

Background

The golden camellia is a traditional medicinal plant in Guangxi and a traditional folk medicine in Zhuang nationality, has wide biological activity and important medicinal value, and is recorded in Guangxi autonomous region Zhuang medicine quality Standard (second volume), has the functions of clearing heat and removing toxicity, and inducing diuresis and reducing edema, and is mainly used for treating diseases such as nephritis, edema, urinary tract infection, sphagitis, dysentery, hypertension and the like. The research shows that the golden camellia mainly contains flavonoid components, and the pharmacological research in vivo and in vitro proves that the golden camellia has various pharmacological effects of resisting oxidation, resisting tumors, regulating blood fat, reducing blood sugar, resisting skin photoaging and the like, and has extremely high economic value.

At present, the research on the golden camellia at home and abroad mainly focuses on the aspects of chemical components, genetic diversity and pharmacological action of the golden camellia, and the research on the aspects of tea processing technology, product quality and the like is very little. In addition, most of the existing golden camellia tea leaves take flowers of the golden camellia as a main tea drink flow, but researches show that the fresh golden camellia leaves contain higher content of beneficial chemical components, so that the development of a tea preparation method taking the fresh golden camellia leaves as raw materials is promoted. Although a small amount of golden camellia preparation process using fresh golden camellia leaves as a preparation raw material exists, the conventional preparation method is mostly adopted to prepare the golden camellia, the prepared golden camellia leaves have the defects of appearance, liquor color, aroma, taste and the like to different degrees, the sensory quality is poor, and the content of beneficial components such as protein, total flavone, total polyphenol, polysaccharide, theanine and the like contained in the finished product is low, so that the golden camellia preparation process is difficult to be accepted by consumers.

Disclosure of Invention

Based on the technical problems, the invention aims to provide a preparation method of camellia nitidissima tea. The camellia nitidissima tea prepared by the preparation method has better sensory evaluation and higher integral content of beneficial ingredients.

In order to achieve the above purpose, the invention provides the following technical scheme:

the invention provides a preparation method of camellia nitidissima tea, which comprises the following preparation steps:

the golden camellia leaf shreds are subjected to enzyme deactivation, rolling and drying to obtain golden camellia leaf tea;

the water removing comprises microwave water removing and steaming.

Preferably, the width of the golden camellia leaf shreds is 1.4-2.0 mm.

Preferably, the microwave enzyme deactivating is carried out at the temperature of 100 ℃ for 30-40 s.

Preferably, the steaming temperature is 140-220 ℃, and the time is 4-5 min.

Preferably, turning over the golden camellia leaf shreds 2-4 min after steaming.

Preferably, before steaming, spreading the golden camellia leaf shreds subjected to microwave enzyme deactivation in a steaming device with the initial temperature of 230-300 ℃.

Preferably, the rolling comprises rolling the tea leaves subjected to water removal into a ball shape, rolling for 5-15 min for the first time, spreading out the ball shape, and rolling for 3-10 min for the second time.

Preferably, the diameter of the dough is 6-10 cm.

Preferably, the drying comprises spreading and drying; the spreading and drying thickness is 1.5-3 cm, the temperature is 30-40 ℃, the humidity is 85-95%, and the time is 3-5 h;

the drying temperature is 35-50 ℃, the thickness is 1.5-3 cm, the time is 2-4 h, and the stirring is carried out once every 30 min.

The invention also provides the camellia nitidissima tea prepared by the preparation method, wherein the protein content in the amino acid content of the camellia nitidissima tea is more than 3.9mg/ml, and the total polysaccharide content is more than 0.5 mg/ml. .

Has the advantages that:

the invention provides a preparation method of camellia nitidissima tea, which takes fresh camellia nitidissima leaves as raw materials, leads the fresh camellia nitidissima leaves to be heated more uniformly in the de-enzyming process through a mode of shredding firstly and de-enzyming, is easy to emit green odor, promotes the formation of good fragrance, better inhibits the enzymatic oxidation of tea polyphenol in the fresh leaves, and improves the sensory quality of the camellia nitidissima tea.

Meanwhile, the invention adopts a combined enzyme-deactivating mode of microwave enzyme-deactivating and steaming, can avoid the conditions of tea leaf frying paste, incomplete enzyme-deactivating and uneven enzyme-deactivating caused by the conventional enzyme-deactivating mode, and steam enzyme-deactivating after microwave enzyme-deactivating can make the leather leaves of the golden camellia softer, thus being beneficial to subsequent rolling to produce juice, better damaging the cell walls of the leaves and promoting the separation of beneficial components in the tea.

Secondly, the invention adopts a preparation mode of shredding the golden camellia tea, and also solves the technical problem that the golden camellia leaves cannot be twisted into strips, so that the finished tea is more beautiful, the fragrance of the tea is better released, and the fragrance is stronger.

Drawings

In order to more clearly illustrate the technical solution in the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below.

FIG. 1 shows tender leaves of Camellia nitidissima according to the preparation method;

FIG. 2 shows the cut Camellia nitidissima of example 1;

FIG. 3 shows the cut Camellia nitidissima after the deactivation of enzymes in example 1;

FIG. 4 shows the twisted golden camellia leaves of example 1;

FIG. 5 is Camellia Chysantha leaf tea obtained in example 1;

FIG. 6 is a standard curve of amino acid content measurement in Experimental example 2;

FIG. 7 is a standard curve of protein content measurement in Experimental example 2;

FIG. 8 is a standard curve of the total polyphenol content measurement in Experimental example 2;

FIG. 9 is a standard curve of the measurement of the total flavone content in Experimental example 2;

FIG. 10 is a standard curve for determination of total polysaccharide content in Experimental example 2.

Detailed Description

the water removing comprises microwave water removing and steaming.

The invention preferably uses fresh leaves of the golden camellia to prepare the golden camellia leaf shreds. The method for obtaining the fresh golden camellia leaves preferably comprises the following steps: picking up golden camellia leaves, cleaning, spreading and airing at a ventilation place at room temperature until the surfaces of the leaves are anhydrous, and obtaining the fresh golden camellia leaves. According to the method, golden camellia leaves are preferably picked in sunny days, and the leaves are preferably tender leaves on new branches, are healthy and have no plant diseases and insect pests; the new branch is lighter in color than the old branch, and the leaves shown as A, B, C, D and E in FIG. 1 are young leaves on the new branch. The room temperature is preferably 23-25 ℃, the spreading and drying thickness is preferably 1-1.5 cm, such as about 2-3 leaves which are staggered and overlapped.

After the fresh golden camellia leaves are obtained, the fresh golden camellia leaves are preferably shredded to obtain golden camellia leaf shreds. The width of the golden camellia leaf shreds is preferably 1.4-2.0 mm, and more preferably 1.5-1.8 mm. Before the fresh golden camellia leaves are shredded, the method preferably further comprises the step of removing petioles on the fresh golden camellia leaves. The preparation mode of the shredding is beneficial to evaporating the moisture of the fresh leaves, so that the tea leaves are softened, the subsequent rolling and forming are facilitated, meanwhile, the tea leaves can be formed more easily, and the technical problem that the leather leaves are not easy to roll into strip ropes is solved.

After the golden camellia leaf shreds are obtained, microwave enzyme deactivation is carried out on the golden camellia leaf shreds, and the temperature of the microwave enzyme deactivation is preferably 100 ℃; the microwave enzyme deactivation time is preferably 30-40 s, more preferably 30-35 s, and further preferably 30 s. The device and related parameters used for microwave enzyme deactivation are not particularly limited, and only the enzyme deactivation temperature is ensured to be reached, for example, a microwave oven is adopted in the embodiment of the invention.

The method comprises the step of steaming the golden camellia leaf shreds subjected to microwave enzyme deactivation to obtain the enzyme-deactivated golden camellia leaf shreds. Before the steaming, the golden camellia leaf shreds subjected to microwave enzyme deactivation are preferably spread in a steaming device, wherein the initial temperature of the steaming device is preferably 230-300 ℃, more preferably 250-280 ℃, and more preferably 270 ℃; the water in the steaming device is preferably in a boiling state; the thickness of the spread is preferably 0.5-2 cm, more preferably 0.8-1.5 cm, and even more preferably 1 cm; the green steaming device is preferably a steamer, a steaming grate or a steaming rack, and more preferably a steamer; preferably, the steaming device further comprises a layer of gauze, for example, when the steaming device is a steamer, a layer of gauze is placed on a steamer tray of the steamer, and the golden camellia leaf shreds after microwave enzyme deactivation are spread on the gauze, and the gauze has the function of preventing the leaf shreds from adhering to the wall bottom and the steamer grate. The specification and the source of the gauze and the steaming device are not particularly limited, and the gauze and the steaming device are used conventionally in the field.

The steaming temperature is preferably 140-220 ℃, more preferably 160-200 ℃, and more preferably 180 ℃; the steaming time is preferably 4-5 min, more preferably 4.5-5 min, and further preferably 5 min. The golden camellia leaf shreds are preferably turned over in the 2 nd to 4 th min of steaming, and more preferably for 3 min. The invention has no special limitation on the turning mode, and the operation is conventional in the field. The tea leaf tea leaves are uniformly heated based on the mode of shredding firstly and then deactivating enzymes, green odor is better dispersed, formation of good aroma is promoted, and enzymatic oxidation of tea polyphenol and the like in fresh leaves is better inhibited. Meanwhile, the combined enzyme-deactivating mode of microwave enzyme-deactivating and steaming not only can promote the softening of leaves, but also is beneficial to the subsequent rolling of juice, better damages cell walls, and can overcome the problems that the conventional enzyme-deactivating mode is easy to cause the tea to be burnt, the enzyme-deactivating is not uniform and the enzyme-deactivating is incomplete.

And (3) obtaining the tea shreds of the camellia chrysantha after the enzyme deactivation, and rolling the tea shreds of the camellia chrysantha after the enzyme deactivation. The rolling preferably comprises the steps of rolling the tea leaves subjected to enzyme deactivation into a ball shape, firstly rolling, spreading the ball shape, and secondly rolling to obtain the rolled tea leaves. The rolling of the invention is preferably dough-like rolling. The diameter of the dough is preferably 6-10 cm, more preferably 6.5-9 cm, and further preferably 7 cm; the first rolling time is preferably 5-15 min, more preferably 7-12 min, and even more preferably 10 min; the second rolling time is preferably 3-10 min, more preferably 4-8 min, and even more preferably 5 min; the kneading surface is preferably pressed and kneaded by the left hand with right hand gravity force for matching stirring; the first twisting force is heavier than the second twisting force. The twisting force is not specially limited, and the twisting force can be adjusted according to the conventional twisting force in the field. Before the rolling, the method also preferably spreads and dries the tea leaves after the enzyme deactivation to a touchable temperature; the spreading and drying thickness is preferably 2-3 cm, and the spreading and drying time is preferably 10 min. The rolling mode can better control the rolling force, effectively destroy tea tissues to roll out golden camellia tea juice, and ensure the shape of tea shreds to make the shape of the golden camellia tea juice more attractive.

After the twisted golden camellia leaf filaments are obtained, the twisted golden camellia leaf filaments are preferably dried to obtain the golden camellia tea. The drying according to the invention preferably comprises spreading and drying. The water content of the dried camellia nitidissima tea is preferably 6-8%.

The invention preferably carries out spreading and drying at constant temperature, wherein the spreading and drying temperature is preferably 30-40 ℃, and more preferably 37 ℃; the spreading and drying humidity is preferably 85-95%, more preferably 88-92%, and even more preferably 90%; the spreading and drying thickness is preferably 1.5-3 cm, and more preferably 2 cm; the spreading and drying time is preferably 3-5 h, and more preferably 4 h. The spreading and drying device is not particularly limited, and any device capable of ensuring the spreading and drying conditions can be used, such as a constant temperature box.

The drying temperature is preferably 35-50 ℃, more preferably 38-48 ℃, and more preferably 45 ℃; the drying thickness is preferably 1.5-3 cm, more preferably 1.6-2.5 cm, and even more preferably 2 cm; the drying time is preferably 2-4 h, and more preferably 3.5 h. The invention preferably turns the tea leaves once every 30 min. The drying device is not particularly limited in the present invention, and any device capable of ensuring the above drying conditions may be used, such as an oven.

The invention preferably further comprises packaging the camellia nitidissima to obtain finished camellia nitidissima tea, wherein the packaging preferably comprises removing unformed tea shreds, removing impurities and packaging; the packaging preferably comprises initial packaging and boutique packaging; the initial packaging is preferably made of paper or cotton cloth; the golden camellia tea is preferably packaged into a packaging box or a packaging box after initial packaging, the specific packaging process is not particularly limited, and the golden camellia tea can be packaged by conventional packaging operation in the field. The packaged camellia nitidissima tea is preferably stored in a cool and dry place.

According to the classification of the tea preparation method, the camellia nitidissima tea prepared by the preparation method preferably belongs to green tea.

The invention also provides the camellia nitidissima tea prepared by the preparation method, wherein the protein content in the amino acid content of the camellia nitidissima tea is more than 3.9mg/ml, and the total polysaccharide content is more than 0.5 mg/ml.

In order to further illustrate the present invention, the following detailed description of the technical solutions provided by the present invention is made with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of the present invention.

Example 1

A preparation method of camellia nitidissima tea comprises the following preparation steps:

picking: fresh leaves of golden camellia are picked in sunny days in 11 months, the fresh leaves are tender leaves on new branches, and the golden camellia is healthy and free of diseases and insect pests. After picking, putting the fresh-keeping agent into a transparent plastic packaging bag, and keeping the temperature at 22 ℃ midway. After the leaves are cleaned, the indoor spreading and drying thickness of the leaves ventilated at the room temperature of 23-25 ℃ is 1-1.5 cm, about 2-3 leaves are staggered and overlapped until the surfaces of the leaves are anhydrous, and about 3 hours.

Shredding: the petioles of 250g of the cleaned leaves were cut off and filaments of 1.4 to 2.0mm width were cut as shown in FIG. 2.

De-enzyming: placing the golden camellia leaf shreds in a microwave oven, spreading the golden camellia leaf shreds with the thickness of about 1cm, adjusting the thickness to about 100 ℃ for deactivation of enzymes for 30s, transferring the golden camellia leaf shreds into a steamer with 270 ℃ water boiling, placing a layer of gauze in a steamer tray, placing the microwave deactivated leaf shreds in the steamer tray, spreading the microwave deactivated leaf shreds for about 1cm, and adjusting the temperature of the steamer tray to 180 ℃ for steam deactivation of enzymes. Turning over the cut tobacco in the 3 rd minute of steam deactivation, and continuing steam deactivation for 2min to turn the cut tobacco to dark yellow as shown in FIG. 3.

Rolling: and (3) spreading and airing the killed cut leaves for about 10min at the thickness of 2-3 cm until the cut leaves are warm and can be touched. Kneading the leaf shreds into a ball with diameter of about 7cm, pressing and kneading with the left hand with heavy force of the right hand, stirring (kneading for 10 min), spreading the ball, and kneading with light force for 5 min. The twisted tobacco filaments are shown in FIG. 4.

Spreading and airing: and (3) transferring the twisted tobacco leaves into a thermostat, spreading the tobacco leaves with the thickness of about 2cm, setting the temperature at 37 ℃ and the humidity at 90%, and keeping the time for 4 hours.

Drying: placing in an oven, spreading to a thickness of about 2cm, setting the temperature at 45 deg.C for 3.5h, turning over every 30min, and finally making the water content of the leaf shreds between 6% and 8% to obtain Camellia Chysantha leaf tea, as shown in FIG. 5.

Packaging: removing unformed tea leaves, removing impurities, wrapping with paper, packaging in a packaging box, and storing in a cool and dry place.

Examples 2 to 4 and comparative examples 1 to 12

Golden camellia tea is prepared in the manner of example 1, except that the related parameters of fixation are different, wherein the related parameters of fixation and the properties after fixation in examples 1-4 and comparative examples 1-12 are shown in table 1.

TABLE 1 deactivation of enzymes of examples 1 to 4 and comparative examples 1 to 12, relevant parameters and post-deactivation properties

As can be seen from Table 1, the golden camellia leaf shreds obtained by the water-removing method in the embodiments 1-4 have the color changed from green to dark, the color is dark yellow, the texture is soft, the shape is not obviously changed, and the green smell is emitted. The golden camellia leaf shreds prepared by the preparation method in the comparative examples 1-12 have changed color, are easy to break, have curled shapes, cannot emit green smell, and have heavy green smell which cannot meet the standard of subsequent rolling.

Comparative examples 13 to 32

Golden camellia tea is prepared according to the method in the example 1, the difference is that the fixation method is different, only microwave fixation, only steaming or only stir-frying are carried out, wherein the fixation related parameters and the properties after fixation in the comparative examples 13-32 are shown in table 2.

Table 2 relative water-removing parameters and properties after water-removing in comparative examples 13-32

As can be seen from table 2, the microwave deactivation or steaming mode alone has a poor deactivation effect on camellia nitidissima, especially cannot remove the green odor in the camellia nitidissima, and meanwhile, the shape and color of the cut leaves obtained by deactivation in the comparative example cannot meet the requirements of the subsequent preparation steps. Meanwhile, the fixation can be realized by adopting a fixation mode, the color, the shape and the smell of the tea can not simultaneously achieve the fixation effect, and the tea is easily burnt due to uneven fixation heating.

Comparative example 33

The white tea processing technology comprises the following steps: withering about 250g of fresh honeysuckle tea leaves for about 2 hours; naturally drying until the water content is 6-8 percent.

Comparative example 34

The processing technology of the dark tea comprises the following steps: taking about 250g of fresh honeysuckle tea leaves, frying the fresh honeysuckle tea leaves in a pot, deactivating enzymes, heating the pot to 220-240 ℃ for 5min, manually kneading the fresh honeysuckle tea leaves, and firstly softly kneading the fresh honeysuckle tea leaves for 5 min-heavily kneading the fresh honeysuckle tea leaves for 10 min-softly kneading the fresh honeysuckle tea leaves for 3 min; drying in sunlight; sun-drying for 2 hours at 8-10 o' clock in the morning; tidal water, the tidal water amount is 30%; solid state fermentation (compaction) in cloth bags; turning the piles every 2 days; deblocking and screening; naturally drying until the water content is 6-8 percent.

Comparative example 35

The yellow tea processing technology comprises the following steps: taking about 250g of fresh honeysuckle tea leaves, withering for 2 hours, and preferably keeping the water content of the leaves between 60 and 68 percent; frying the pan to remove the green, wherein the temperature of the pan is 220-240 ℃ and the time is 5 min; manually kneading, and firstly softly kneading for 5 min-heavily kneading for 10 min-softly kneading for 3 min; the tea is stewed to be yellow, the color of the leaves is changed into yellow green, the green smell disappears, the strong fragrance is emitted for 7 days, and the tea is naturally dried until the water content is 6-8 percent.

Comparative example 36

The processing technology of the green tea comprises the following steps: withering about 250g of fresh honeysuckle tea leaves for about 2 hours, wherein the water content is 60-68%; performing green-making, namely thinly spreading withered leaves on a water screen, shaking the green leaves for 2min and standing for 1min for 3-5 times alternately, and stopping after the 3 rd shaking is performed and the 5 th time is performed by assisting a hand (namely, the leaves are furled by two hands, and are held up and lightly tapped and shaken); frying the pan to remove the green, wherein the temperature of the pan is 220-240 ℃ and the time is 5 min; manually kneading, and firstly softly kneading for 5 min-heavily kneading for 10 min-softly kneading for 3 min; naturally drying until the water content is 6-8 percent.

Comparative example 37

The green tea processing technology comprises the following steps: taking about 250g of fresh honeysuckle tea leaves, frying in a pot, deactivating enzymes, heating the pot to 220-240 ℃, and keeping for 5 min; manually kneading, and firstly softly kneading for 5 min-heavily kneading for 10 min-softly kneading for 3 min; deblocking; drying at the pot temperature of 120-130 ℃ for 10 min. The water content of the raw tea is 6-8%.

Comparative example 38

The black tea processing technology comprises the following steps: taking about 250g of fresh honeysuckle tea leaves, withering for 2 hours, and preferably keeping the water content of the leaves between 60 and 68 percent; manually kneading, and firstly softly kneading for 5 min-heavily kneading for 10 min-softly kneading for 3 min; fermenting for 15 days, wherein the temperature is controlled to be 24-25 ℃, the humidity is 85-97%; naturally drying until the water content is 6-8 percent.

Experimental example 1

Sensory evaluation was performed on the tea leaves prepared in example 1 and comparative examples 33 to 38, and the criteria for sensory evaluation are shown in table 3, and the results are shown in table 4.

TABLE 3 sensory evaluation criteria

In the present invention, 20 persons were randomly invited to perform sensory evaluation on the appearance, liquor color, aroma, taste and leaf bottom of the tea leaves prepared in example 1 and comparative examples 33 to 38, respectively, the average value of 20 persons was taken, and then the final score of each tea leaf was calculated by the proportion of each factor: the calculation formula is as follows: the total score is the mean value of each factor of sigma multiplied by the corresponding score coefficient.

Table 4 sensory evaluation results of tea leaves prepared in example 1 and comparative examples 33 to 38

	Comparative example 33	Comparative example 34	Comparative example 35	Comparative example 36	Comparative example 37	Comparative example 38	Example 1
								Outer shape	90	80	90	90	82	83	95
Color of soup	88	98	91	92	89	90	93
								Fragrance	96	95	94	90	94	80	93
Taste of the product	95	95	94	92	92	80	93
								Leaf bottom	90	80	85	85	85	85	93
Total score	92.8	90.05	91.8	90.3	89	82.25	93.5

As can be seen from table 4, the camellia nitidissima tea prepared by the preparation method of the invention has better quality than the camellia nitidissima prepared by the conventional preparation method in appearance, liquor color, aroma, taste and leaf bottom, and has better comprehensive sensory quality.

Experimental example 2

The contents of amino acid, protein, total flavone, total polyphenol and total polysaccharide in the tea leaves prepared in the example 1 and the comparative examples 33 to 38 are measured by adopting an ultraviolet spectrophotometer, and the measuring methods are respectively as follows: wherein the particle size of the sample powder used in each measurement method is not more than 60 mesh.

Determination of amino acid content

The standard curve drawing method comprises the following steps:

1. accurately weighing 11.7mg of theanine, and dissolving the theanine in 25mL of distilled water to obtain a mother solution;

2. accurately sucking 0.0mL, 0.8mL, 0.85mL, 0.9mL, 0.95mL and 1.0mL of mother liquor, and metering to 5mL of volumetric flask as working solution;

3. accurately sucking 2mL of working solution, adding 1mL of phosphate buffer solution and 1mL of 2% ninhydrin solution, heating in boiling water bath for 15min, taking out, standing for 10min, and cooling;

4. the absorbance was measured at a wavelength of 570nm using a 1cm cuvette, and an amino acid standard curve was plotted.

The method for measuring the sample comprises the following steps:

1. preparation of a sample: accurately weighing 1.1g of tea powder sample, adding distilled water into a 15mL volumetric flask, putting into an ultrasonic machine, and carrying out ultrasonic treatment at 40 ℃ for 30min (the ultrasonic frequency is 40 KHZ);

2. after ultrasonic treatment, the mixture is poured into a 50mL centrifuge tube, the volumetric flask is rinsed twice with 10mL of distilled water, then the mixture is poured into the 50mL centrifuge tube, and the centrifuge tube is placed into a centrifuge for 10min at 4 ℃ and 4000 r/min.

3. Accurately sucking 3mL of sample solution from a centrifuge tube and putting the sample solution into a 5mL volumetric flask;

4. adding phosphate buffer solution 1mL and 2% ninhydrin solution 1mL, boiling water bath for 15min, taking out, standing for 10min, and cooling;

5. the absorbance was measured at a wavelength of 570nm using a 1cm cuvette and recorded well.

Protein content determination

The standard curve drawing method comprises the following steps:

1. accurately weighing 100mg of bovine serum albumin standard, and dissolving the bovine serum albumin standard in 50mL of distilled water to obtain 2mg/mL of bovine serum albumin standard solution as mother solution;

2. accurately sucking 4mL of mother liquor and 1mL of Coomassie brilliant blue reagent into a 5mL volumetric flask, covering a stopper, reversing and uniformly mixing, standing at room temperature for 2min, measuring an absorbance at 595nm by using a 1cm cuvette, and drawing a protein standard curve.

The method for measuring the sample comprises the following steps:

1. accurately weighing 0.4g of tea powder sample into a mortar, adding 5mL of 0.1mol/mLNaOH solution, grinding into homogenate, transferring into a 50mL centrifuge tube, and rinsing the mortar four times by taking 40mL of 0.1mol/mLNaOH solution.

2. Standing for 45min indoors, placing in a centrifuge at 4 deg.C and 4000r/min, and centrifuging for 20 min.

3. Accurately sucking 3mL of centrifuged supernatant, adding 1.5mL of Coomassie brilliant blue reagent into a 5mL volumetric flask, plugging, reversing and mixing uniformly, standing at room temperature for 2min, measuring the light absorption value at 595nm by using a 1cm cuvette, and recording.

Determination of total flavone content

The standard curve drawing method comprises the following steps:

1. accurately weighing a rutin standard substance, adding 60% ethanol, fixing the volume to a 100mL volumetric flask, and obtaining 0.2mg/mL rutin standard substance stock solution as mother solution;

2. accurately sucking 0.0mL, 0.4mL, 0.8mL, 1.2mL, 1.6mL and 2.0mL of mother liquor, and metering to a 5mL volumetric flask;

3. 60% ethanol is added into 5mL volumetric flasks respectively to obtain working solution with constant volume.

4. Transferring the working solution with constant volume to a 10mL volumetric flask, adding 0.3mL of 5% sodium nitrite solution, shaking up, and standing for 6 min;

5. adding 0.3mL of 10% aluminum nitrate solution, shaking up, and standing for 6 min;

6. adding 4mL of 0.4% aluminum nitrate solution, shaking up, and standing for 12 min; measuring absorbance at 510nm wavelength with 1cm cuvette, and drawing total flavone standard curve.

The method for measuring the sample comprises the following steps:

1. accurately weighing 0.4g of tea powder sample, adding 60% ethanol solution into a 25mL volumetric flask, putting into an ultrasonic machine, and carrying out ultrasonic treatment at 40 ℃ for 30 min;

2. after ultrasonic treatment, the mixture is poured into a 50mL centrifuge tube, the volumetric flask is rinsed twice with 20mL of 60% ethanol solution, and then the rinsing solution is poured into the 50mL centrifuge tube again, and the centrifuge tube is placed into a centrifuge for 15min at 4 ℃ and 4000 r/min.

3. Accurately sucking 1mL of centrifuged supernatant, transferring the supernatant into a 10mL volumetric flask, and adding 9mL of 60% ethanol solution to perform constant volume to obtain working solution;

4. accurately sucking 1mL of working solution into a 10mL volumetric flask, adding 0.3mL of 5% sodium nitrite solution, shaking up, and standing for 6 min;

6. adding 4mL of 0.4% aluminum nitrate solution, shaking up, and standing for 12 min; the absorbance was measured at a wavelength of 510nm using a 1cm cuvette and recorded.

Total polyphenol content determination

The standard curve drawing method comprises the following steps:

1. accurately weighing 3.2mg of gallic acid standard, and dissolving in 25mL of distilled water to obtain 0.01mg/mL of standard stock solution;

2. respectively transferring 0.0mL, 0.2mL, 0.4mL, 0.6mL, 0.8mL and 1.0mL of gallic acid standard storage solution into a 15mL volumetric flask;

3. 3.5mL, 3.3mL, 3.1mL, 2.9mL, 2.7mL and 2.5mL of distilled water were added into the volumetric flask of the previous step;

4. adding 5mL of 10% forinophenol reagent, shaking up, and standing for 5 min;

5. adding 7.5% Na₂CO₃Shaking the solution 4mL evenly;

6. after reaction at room temperature in the dark for 1h, the absorbance was measured at 765nm wavelength in a 1cm cuvette, and a total polyphenol standard curve was plotted.

Adding distilled water into a tea powder sample, fixing the volume to a 20mL volumetric flask, putting the volumetric flask into an ultrasonic machine, and carrying out ultrasonic treatment at 40 ℃ for 30 min;

2. after the ultrasonic treatment, the mixture is poured into a 50mL centrifuge tube, the volumetric flask is rinsed twice with 20mL of distilled water, and then the rinsing solution is poured into the 50mL centrifuge tube again, and the centrifuge tube is placed into a centrifuge for 15min at 4 ℃ and 4000 r/min.

3. Accurately sucking 1mL of centrifuged supernatant, adding 5mL of 10% forrin phenol reagent, shaking up, and standing for 5 min;

4. adding 7.5% Na₂CO₃Shaking the solution 4mL evenly;

5. after reaction at room temperature in the dark for 1h, the absorbance was measured at 765nm using a 1cm cuvette and recorded.

Total polysaccharide assay

The standard curve drawing method comprises the following steps:

1. accurately weighing 16mg of glucose standard substance, and using distilled water to be fixedly contained in a 50mL volumetric flask to obtain 0.32mg/mL glucose standard stock solution;

2. respectively transferring 0.0 muL, 50 muL, 100 muL, 150 muL, 200 muL and 250 muL of glucose standard stock solution into a 1mL volumetric flask;

3. respectively adding 1000 mul, 950 mul, 900 mul, 850 mul, 800 mul and 750 mul distilled water into the volumetric flask of the step 1mL to be used as working solution;

4. adding 0.6mL of 3% phenol solution into the working solution, and shaking up; then slowly adding 5mL of concentrated sulfuric acid, and shaking up gently; placing in boiling water bath for 25 min.

5. After being taken out, the solution is placed indoors for 10min to be cooled, and a 1cm cuvette is used for measuring the light absorption value at 490nm wavelength to draw a total polysaccharide standard curve.

The method for measuring the sample comprises the following steps:

1. accurately weighing 0.3g of tea powder sample, adding distilled water, fixing the volume to a 15mL volumetric flask, putting into an ultrasonic machine, and carrying out ultrasonic treatment at 40 ℃ for 30 min;

2. after the ultrasonic treatment, the mixture is poured into a 50mL centrifuge tube, the volumetric flask is rinsed with 15mL of distilled water for three times, and then the rinsing liquid is poured into the 50mL centrifuge tube again, and the centrifuge tube is placed into a centrifuge for 15min at 4 ℃ and 4000 r/min.

3. Accurately sucking 1mL of centrifuged supernatant, adding 4mL of distilled water into a 5mL volumetric flask for dilution to serve as working solution;

4. sucking 1mL of working solution and adding 0.6mL of 3% phenol solution, and shaking up; then slowly adding 5mL of concentrated sulfuric acid, and shaking up gently; placing in boiling water bath for 25 min.

5. After taking out, the sample was left indoors for 10min to cool, and the absorbance was measured at 490nm using a 1cm cuvette and recorded.

Data of standard curves of amino acids, proteins, total flavonoids, total polyphenols and total polysaccharides are shown in Table 6 and FIGS. 6 to 10, in which the ordinate is absorbance value.

TABLE 6 Standard Curve data for amino acids, proteins, Total Flavonoids, Total polyphenols and Total polysaccharides

The contents of amino acids, proteins, total flavonoids, total polyphenols and total polysaccharides in example 1 and comparative examples 23 to 28 measured according to the above standard curve data are shown in table 7.

TABLE 7 contents of amino acids, proteins, total flavonoids, total polyphenols and total polysaccharides in example 1 and comparative examples 33 to 38

As can be seen from table 7, the contents of protein and polysaccharide in the camellia nitidissima tea obtained by the preparation method of the present invention are significantly higher than the contents of the corresponding components in the tea prepared in the comparative example; the amino acid content of the tea prepared by the method is equivalent to that of white tea, yellow tea, green tea and green tea, and is obviously higher than that of black tea and black tea; the content of the total flavonoids is in the same level with the whole tea, and the difference between various kinds of tea is not great; the content of tea polyphenol is lower than that of white tea, but in terms of tea polyphenol, the higher the content of tea polyphenol in tea is, the better the content of tea polyphenol is, and a proper amount of tea polyphenol is not needed for people to influence the health. Therefore, in conclusion, the beneficial component content of the camellia nitidissima tea obtained by the preparation method is higher overall.

The examples show that the camellia nitidissima tea prepared by the preparation method provided by the invention has better sensory evaluation and higher integral content of beneficial ingredients.

The invention is funded by a capital project driven by Guangxi innovation and developed specially (Guike AA18118049-7) and a Guangxi natural science foundation key project (2020GXNSFDA297029), and is explained in detail.

Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and all of the embodiments belong to the protection scope of the present invention.

Claims

1. A preparation method of camellia nitidissima tea is characterized by comprising the following preparation steps:

the water removing comprises microwave water removing and steaming.

2. The preparation method according to claim 1, wherein the golden camellia leaf filaments have a width of 1.4-2.0 mm.

3. The preparation method according to claim 1, wherein the microwave enzyme deactivation is carried out at 100 ℃ for 30-40 s.

4. The preparation method according to claim 1, wherein the steaming is carried out at a temperature of 140 to 220 ℃ for 4 to 5 min.

5. The preparation method according to claim 4, wherein the golden camellia leaf shreds are turned over at the 2-4 min of steaming.

6. The preparation method according to claim 4 or 5, wherein before the steaming, the golden camellia leaf shreds after microwave enzyme deactivation are flatly spread in a steaming device with the initial temperature of 230-300 ℃.

7. The preparation method according to claim 1, wherein the rolling comprises rolling the deactivated golden camellia leaves into a mass shape, a first rolling for 5-15 min, a spreading and rolling for 3-10 min.

8. The method according to claim 7, wherein the diameter of the dough is 6 to 10 cm.

9. The method of claim 1, wherein the drying comprises spreading and drying; the spreading and drying thickness is 1.5-3 cm, the temperature is 30-40 ℃, the humidity is 85-95%, and the time is 3-5 h;

10. Camellia chrysantha tea prepared by the preparation method of any one of claims 1 to 9, wherein the content of protein in the camellia chrysantha tea is more than 3.9mg/ml, and the content of total polysaccharide in the camellia chrysantha tea is more than 0.5 mg/ml.