A tea spreading / withering method

Abstract

The present invention belongs to the technical field of tea, and in particular to a method for spreading / withering tea leaves. The method comprises: setting a laser light field at a place for spreading / withering fresh tea leaves, and performing laser treatment when the tea leaves are spread / withered; the laser treatment uses a blue laser light source with a wavelength of 435 to 455 nm and / or a red laser light source with a wavelength of 645 to 665 nm, and when the blue laser and the red laser are used, the red-blue light intensity ratio is controlled to be 0.2 to 9:1, and the total light intensity is 0.1 to 5.0 μmol·m ‑2 ·s ‑1 ; The laser treatment duration is ≥ 1 h. The present invention performs laser supplementary lighting treatment during the spreading / withering process of tea leaves, so that fresh tea leaves form secondary accumulation of nutrients during the spreading / withering process, effectively regulate the nutritional components and nutritional value of tea leaves, and can simultaneously improve the flavor quality and nutritional quality of tea leaves. The overall method is simple and efficient, and the use of laser supplementary lighting has lower energy consumption and saves more resources.

Description

Technical Field

[0001] The invention belongs to the technical field of tea, and in particular relates to a tea spreading / withering method. Background Art

[0002] my country is a major tea-producing country with many varieties of tea. Although the production processes of different teas are different, the first step in the processing of all teas is to spread or wither the fresh leaves.

[0003] The environmental factors affecting the spreading and withering of tea leaves mainly include light, temperature, humidity, ventilation, etc. The spreading / withering process refers to the process of treating tea leaves by light or heat. In this process, light has an important influence on the quality of tea leaves. The conventional spreading / withering process requires the rapid drying of tea leaves in conjunction with light. In traditional processes, fresh tea leaves are mainly spread / withered naturally and by sunlight. This is often affected by the weather, takes a long time to process, and the production time and quality of tea leaves are difficult to guarantee. Artificial light sources have the characteristics of stable and adjustable light intensity, which is suitable for large-scale production. However, the actual treatment effect on tea leaves is still not as good as natural light, so the actual use effect is also relatively limited.

[0004] With the development of tea craftsmanship, it has been discovered that using specific artificial light sources to assist with withering can cause certain changes and improvements in the taste of tea, so some research has been conducted.

[0005] For example, in recent years, the application of LED light sources in tea withering has aroused people's interest. Representative existing patent technologies include CN104642574A, which provides a tea withering device based on LED light sources and a corresponding withering method, and CN104430951A, which provides a method for light withering of black tea, which uses a yellow, red or orange LED light source for single light source irradiation withering, such as CN105994828A, which provides a method for light withering of orange light, and CN105104602A, which provides a method for preservation of fresh green tea leaves, which provides a method for light withering of yellow monochromatic light. However, the above methods are all based on light withering treatment with general quality light, and among them, CN104430951A, CN105994828A and CN105104602A control the Lx parameter of general quality light to achieve control of the withering process. However, LED light sources still have problems such as wide spectral range, large light dispersion, low photoelectric conversion efficiency, high energy consumption, small irradiation area, low irradiation height, and difficulty in accurately coordinating light quality ratio and power, which limits their application in the field of tea processing. Summary of the invention

[0006] In order to solve the problems that the existing tea withering adopts sunlight withering or conventional general quality light, such as LED light for assisted withering, the actual effect is relatively limited, and the quality of tea flavor is mainly improved by consuming nutrients, resulting in a decrease in the actual nutritional value of the tea, the present invention provides a tea spreading / withering method.

[0007] The objects of the present invention are:

[0008] 1. Use laser light source to effectively assist in spreading / withering tea leaves;

[0009] 2. Achieve simultaneous improvement of tea flavor quality and tea nutritional value quality during auxiliary spreading / withering treatment;

[0010] 3. Reduce the auxiliary spreading / withering energy consumption generated during the actual spreading / withering process.

[0011] To achieve the above objectives, the present invention adopts the following technical solutions.

[0012] A tea spreading / withering method,

[0013] The method comprises:

[0014] A laser light field is set up at the tea leaf spreading / withering site, and laser treatment is performed when the tea leaves are spread / withering;

[0015] The laser treatment uses a blue laser light source with a wavelength of 435 to 455 nm and / or a red laser light source with a wavelength of 645 to 665 nm to control the red-blue light intensity ratio to be 0.2 to 9:1, and the total light intensity to be 0.1 to 5.0 μmol·m -2 ·s -1 ;

[0016] The laser treatment time is ≥1 h.

[0017] In the technical solution of the present invention, the key lies in the selection of laser and the reasonable and effective regulation of parameters such as laser wavelength, red-to-blue light intensity ratio and total light intensity.

[0018] For the existing tea spreading / withering schemes, most of them use sunlight or LED general quality light for irradiation treatment, and all of them have the same characteristics, that is, they are actually based on the effect of light radiation heat, and the radiation heat of light is used to achieve the speed of spreading / withering and the more uniform water loss of tea leaves, and to a certain extent consume some nutrients to adjust the taste. As recorded in paragraph

[0036] of the technical scheme of CN104430951A, under different light quality treatments, the content of tea polyphenols is further improved, but in the actual working process, the improvement of its content is not caused by its net quality improvement, but the consumption of nutrients in the actual light supplementation treatment process of the scheme, thus resulting in the effect of relatively improving the content of tea polyphenols. As recorded in paragraph

[0069] of the technical scheme of CN105104602A, under different light quality treatments, the content of tea polyphenols is also further improved. It can be seen that the effect of light supplementation and withering is to consume nutrients. However, in the present invention, researchers found that after the fresh tea leaves are picked, they still have life activities such as photosynthesis, respiration, and transpiration. After the tea leaves are plucked and separated from the body, part of the material transmission is blocked, and the general light cannot directly and effectively achieve the above-mentioned promotion effect. That is, photosynthesis cannot be carried out under the action of general light, or it is very difficult to carry out photosynthesis, because the wavelength range of the general light source is wide and the light source generates a lot of heat, causing the leaves to lose water quickly, thus affecting the further optimization and accumulation of fresh tea leaf substances.

[0019] In this regard, the difference of the present invention is that laser is used for supplementary light spreading / withering. Laser is significantly different from common general light sources such as LED light sources, mainly because the high coherence and energy density of laser are much higher than common general light sources, so the effects produced are also far different. For example, the blue light penetration ability of general light sources is weak, and it is usually not directly absorbed by plant chloroplasts. It needs to be converted into lutein and carotene before it can be transferred to chlorophyll for photosynthesis. However, under the laser light source, the defect of shallow blue light penetration is compensated and can be directly absorbed by chloroplasts. In the case where general light cannot promote photosynthesis of tea leaves after picking in vitro during supplementary light withering, laser supplementary light withering can produce completely different technical effects. Through the selection and regulation of appropriate light bands, light intensity ratios, and total light intensity, secondary controllable accumulation and conversion of nutrients are produced, which is significantly better and completely different from the effect of "consuming nutrients and adjusting content ratio" of general light supplementary light withering.

[0020] At the same time, the present invention finds that when laser light supplementation is used for spreading or withering, with the activation of various hydrolases and oxidases in leaf cells, a series of complex biochemical reactions such as decomposition of macromolecular substances and synthesis of new substances will occur in the leaves, low molecular weight proteins and polypeptide compounds in leaf protein will undergo hydrolysis reactions under the action of enzymes, free amino acids will increase, the proportion and content of the main chemical components in fresh tea leaves will change, and the soluble content will increase. That is, under the action of laser at low intensity, fresh tea leaves can be photosynthesized quickly, prompting the leaves to further synthesize effective substances such as sugars and amino acids after picking, increase the content of free amino acids and water-soluble sugars, and change the structural ratio of chlorophyll, by inducing and increasing the activity of certain enzymes in fresh leaves, promoting enzymatic hydrolysis of proteins in leaves to generate free amino acids, thereby facilitating the formation of substances with aroma and flavor, and providing a material basis for biochemical changes in subsequent processes.

[0021] As a preference,

[0022] The laser light source of the laser light field irradiates the fresh tea leaves in a top illumination, side illumination and / or oblique illumination manner.

[0023] The laser light source can be assembled into various lamps as needed, including but not limited to straight tube lamps, UFO lamps, ring lamps, and projection lamps. The laser light source can be used alone or in combination with existing light sources.

[0024] As a preference,

[0025] The laser light source is arranged at a distance of ≥0.5 m from the fresh tea leaves.

[0026] Laser light sources have high energy and can easily scorch the tea leaves when they are too close to the withering tea leaves.

[0027] As a preference,

[0028] The laser light source is a semiconductor laser light source.

[0029] Semiconductor laser light sources can more effectively ensure a uniform light output layout.

[0030] The beneficial effects of the present invention are:

[0031] The present invention performs laser supplementary lighting treatment during the withering process of tea leaves, so that fresh tea leaves form secondary accumulation of nutrients during the withering process, effectively regulates the nutritional components and nutritional value of the tea leaves, and can simultaneously improve the flavor quality and nutritional quality of the tea leaves. The overall method is simple and efficient, and the use of laser supplementary lighting has lower energy consumption and saves more resources. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0033] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0034] Unless otherwise specified, the conventional spreading withering processes described in the embodiments of the present invention are all conventional tea spreading withering processes.

[0035] Example 1

[0036] A tea spreading / withering method, comprising the following steps:

[0037] 1) Arrange the laser light source in the tea leaf withering place, 2 meters above the surface of the fresh leaves, with top illumination, and each lamp irradiates an area of ​​60 square meters. Adjust the projection angle of the light source to make the light field evenly distributed;

[0038] 2) After picking, the fresh tea leaves (medium tea 108) are spread in the withering tank with a thickness of 10 cm;

[0039] 3) Before the conventional withering process, set the laser light source, select a blue laser light source with a wavelength of 455 nm and a red laser light source with a wavelength of 665 nm, adjust the red-blue ratio to 8:1, and the total laser intensity to 0.8 μmol·m -2 ·s -1 After the fresh leaves are spread out and the withering process begins, the laser light source is started, and the laser supplementary lighting treatment is performed in the first 4 hours of the conventional withering process;

[0040] 4) After withering, the fresh tea leaves are processed and made into rock tea according to existing technology.

[0041] This group is labeled BG1.

[0042] Comparative Example 1

[0043] Based on Example 1:

[0044] Step 3) Use natural light as the light source as CK1-1;

[0045] Step 3) Replace the laser light source with an LED light source with equal light intensity ratio and total light intensity as CK1-2;

[0046] Step 3) With equal light intensity ratio and total light intensity of 400 μmol·m -2 ·s -1 The LED light source replaces the laser light source as CK1-3.

[0047] In the above experimental groups, due to the different characteristics of LED light and laser, under the same total light intensity, the CK1-2 group can almost be regarded as a control group without light.

[0048] Among them, the sensory evaluation of tea leaves was conducted on the BG1 and CK1-1 test groups, as shown in the following table.

[0049] Group Appearance / 25% Soup color / 10% Aroma / 25% Flavor / 30% Leaf bottom / 10% Total score BG1 Tight knot, slightly curled, slightly black and smooth (91) Bright orange-red (90.5) Sweeter, slightly fruity (91.5) More mellow, sweeter (90.5) Soft, smooth, with buds, bright red (89) 90.7 CK1-1 Tight knot, slightly curled, slightly black and smooth (91) Orange-red, still bright (85) Still sweet, slightly fruity (90) Glycol (89) Soft, smooth, with buds, bright red (89) 89.8

[0050] In addition, the quality of tea leaves in groups BG1 and CK1-1 to 3 was physically and chemically identified. The identification results are shown in the following table.

[0051] Group Tea polyphenols / % Free amino acids / % Soluble sugar / % Caffeine / % BG1 13.2 4.6 2.9 3.9 CK1-1 12.9 4.2 2.4 4.5 CK1-2 11.3 3.9 2.1 4.8 CK1-3 13.5 4.0 2.2 4.3

[0052] Combined with the above table, it can be seen that under the condition of similar water content, the tea polyphenols, free amino acids and soluble sugar contents of the BG1 test group tea treated by the technical solution of the present invention are significantly increased compared with the CK1-1 test group tea, and the aminophenol ratio is increased by 7%, which significantly improves the overall flavor quality of the tea. And by comparing the BG1 test group and the CK1-2 test group, it can be seen that there are significant differences in the supplementary light treatment between laser light quality and general light quality. When the CK1-1 test group and the CK1-3 test group used high-intensity general light quality, the content of tea polyphenols and free amino acids in the CK1-1 test group decreased, and the content of tea polyphenols in the CK1-3 test group increased, but the content of free amino acids decreased, indicating that general light withering is positively correlated with the tea polyphenol content of tea leaves, but for free amino acids, it shows that specific red and blue general light supplementary light cannot effectively inhibit the loss of free amino acids. After testing, the use of orange-yellow LED supplementary light withering can inhibit the loss of aromatic amino acids and sweet amino acids to a certain extent, but the loss of umami amino acids and fresh amino acids is still inevitable. However, it can be seen from the BG1 test group that the content of free amino acids has been increased when laser supplementary light withering is used. This is because red and blue lasers are conducive to promoting the decomposition of proteins and the accumulation of amino acids, which makes the content of free amino acids in the BG1 test group increase instead of decrease. The caffeine content in the BG1 test group is the lowest, which shows that the supplementary light operation during the withering process of tea leaves has a significant effect on the synthesis of caffeine in the leaves. Comparison between the CK1-1 test group and the CK1-2 test group shows that the synthesis of caffeine under weak light conditions is more advantageous, which is also in line with the synthesis conditions of caffeine in the leaves, while the caffeine content of CK1-3 decreases under strong light conditions, which improves the flavor quality of the tea soup and makes the astringency lighter, which is also in line with the rule that strong light inhibits the synthesis of caffeine in the leaves. However, the BG1 test group of the technical solution of the present invention uses laser supplementary light with the same light intensity as CK1-2, but the caffeine content is significantly reduced. This is because the assisted withering of laser light quality can effectively achieve the degradation of caffeine.

[0053] In addition, the main component of tea polyphenols that is beneficial to humans is EGCG (catechin). Further characterization tests were conducted on the EGCG content of each group, and the results are shown in the following table.

[0054] Group BG1 CK1-1 CK1-2 CK1-3 EGCG / % 7.03 6.32 5.71 6.12

[0055] It can be seen from the above table that although the total content of tea polyphenols after the laser light supplementation treatment of the present invention is not significantly increased, the actual effective ingredient EGCG content is significantly increased, and the amino acid and soluble sugar contents are also much higher than those of other groups. It can be seen that the laser light supplementation treatment of the present invention has a significant impact on the nutritional composition of tea, which not only improves the flavor quality of the tea, but also further improves the nutritional value quality.

[0056] In addition, the dry weight of the BG1, CK1-1, CK1-2 and CK1-3 test groups was characterized, among which the dry weight of the BG1 test group, CK1-1 and CK1-2 test groups were almost the same. Taking CK1-1 as the blank control standard, the dry weight of the tea obtained in the BG1 test group was 99.7% of the dry weight of the tea obtained in the CK1-1 test group, the dry weight of the tea obtained in the CK1-2 test group was 100.9% of the dry weight of the tea obtained in the CK1-1 test group, and the dry weight of the tea obtained in the CK1-3 test group was only 96.2% of that in the CK1-1 test group, which showed a significant decrease. This also confirms the conclusion that the increase in effective ingredients brought about by the aforementioned existing LED supplementary lighting solution is achieved at the expense of and consumption of other nutrients.

[0057] Example 2

[0058] A tea spreading / withering method, comprising the following steps:

[0059] 1) Place the laser light source at the place where the fresh tea leaves are spread, 0.5 meters above the surface of the fresh leaves, with side illumination, and adjust the projection angle of the light source to make the light field evenly distributed;

[0060] 2) After picking the fresh tea leaves (Longjing 43), spread them in the spreading trough with a thickness of 3 cm;

[0061] 3) Before the conventional spreading process begins, set up the laser light source, select a blue laser light source with a wavelength of 435 nm and a total laser intensity of 0.1 μmol·m -2 ·s -1 , laser light supplementation treatment is performed 1 hour before the conventional spreading process;

[0062] 4) After spreading, the fresh tea leaves are processed and made into green tea according to existing technology.

[0063] This group is marked as BG2.

[0064] Comparative Example 2

[0065] Based on Example 2:

[0066] Step 3) Use natural light as the light source as CK2-1;

[0067] Step 3) Replace the laser light source with a blue LED light source of equal light intensity as CK2-2;

[0068] Step 3) With a light intensity of 400 μmol·m -2 ·s -1 The blue LED light source replaces the laser light source as CK2-3.

[0069] In the above experimental groups, due to the different characteristics of LED light and laser, under the same total light intensity, the CK2-2 group can almost be regarded as a control group without light.

[0070] Among them, the sensory evaluation of tea leaves was conducted on the BG2 and CK2-1 test groups, as shown in the following table.

[0071] Group Appearance / 25% Soup color / 10% Aroma / 25% Flavor / 30% Leaf bottom / 10% Total score BG2 Flat and smooth, tender green and fresh (90) Bright green, clear (90) Long-lasting fragrance (90) Fresh, mellow and dry (93) Even, bright green (91) 91 CK2-1 Flat and smooth, tender green and fresh (90) Bright green, clear (86) Fresh and lasting fragrance (84) Fresh and refreshing (85) Even, bright green (91) 86.7

[0072] In addition, the quality of tea leaves in groups BG2 and CK2-1 to 3 was physically and chemically identified. The results are shown in the following table.

[0073] Group Tea polyphenols / % Amino Acid / % Soluble sugar / % Caffeine / % BG2 19.1 4.3 2.6 4.1 CK2-1 18.6 3.8 2.2 4.3 CK2-2 16.3 3.5 1.9 4.6 CK2-3 18.9 3.7 2.0 4.2

[0074] The test results of Example 1 and Comparative Example 1 show that the ratio of aminophenol to tea increases by 10% after laser light supplementation treatment, which has a direct impact on the nutritional composition of tea leaves. The EGCG content is also tested and characterized. The results are shown in the following table.

[0075] Group BG2 CK2-1 CK2-2 CK2-3 EGCG / % 11.97 11.81 8.69 9.72

[0076] From the above table, it can be seen that although the total content of tea polyphenols after the laser light supplementation treatment of the present invention is not significantly increased, the actual effective ingredient EGCG content is slightly higher than that of the CK2-1 test group, significantly higher than that of the CK2-2 and CK2-3 test groups, and the free amino acid and soluble sugar content is also much higher than that of other groups. It can be seen that the laser light supplementation treatment of the present invention has a significant impact on the nutritional composition of tea leaves, so that not only the flavor quality of tea leaves is improved, but also the nutritional value quality is further improved. However, compared with the test group of Example 1, it can be seen that the improvement of flavor quality by blue light alone is relatively more significant, but the actual nutritional value quality improvement effect is weaker than the test group of red and blue light synergy.

[0077] In addition, the dry weight of the BG2, CK2-1, CK2-2 and CK2-3 test groups was characterized. The dry weight difference between the BG2, CK2-1 and CK2-2 test groups was ≤1% of the dry weight of the CK2-1 test group, while the dry weight of the tea obtained from the CK2-3 test group was only 97.6% of that of the CK1-1 test group, which was a significant decrease.

[0078] Example 3

[0079] A tea spreading / withering method, comprising the following steps:

[0080] 1) Place the laser light source at the tea leaf withering site, 3 meters above the surface of the fresh leaves, in top illumination mode, and adjust the projection angle of the light source to make the light field evenly distributed;

[0081] 2) After picking the fresh tea leaves (Fuding Dahao), spread them in the withering tank with a thickness of 15 cm;

[0082] 3) Before the conventional withering process begins, set up the laser light source, select a red laser light source with a wavelength of 645 nm and a total laser intensity of 5.0 μmol·m -2 ·s -1 After the fresh leaves are spread out and the withering process begins, the laser light source is started, and the laser supplementary lighting treatment is performed for the first 6 hours in the conventional withering process;

[0083] 4) After withering, the fresh tea leaves are subsequently processed and made into white tea according to existing technology.

[0084] This group is marked as BG3.

[0085] Comparative Example 3

[0086] Based on Example 3:

[0087] Step 3) Replace the laser light source with artificial natural light (using full-spectrum LED to simulate the sunlight environment around 13:00 at noon) as CK3-1;

[0088] Step 3) Replace the laser light source with a red LED light source of equal light intensity as CK3-2;

[0089] Step 3) With a light intensity of 400 μmol·m -2 ·s -1 The red LED light source replaces the laser light source as CK3-3.

[0090] In the above experimental groups, due to the different characteristics of monochromatic LED light and laser, under the same total light intensity, the CK3-2 group can almost be regarded as a control group without light.

[0091] Among them, the sensory evaluation of tea leaves was conducted on the BG3 and CK3-1 test groups, as shown in the following table.

[0092] Group Appearance / 25% Soup color / 10% Aroma / 25% Flavor / 30% Leaf bottom / 10% Total score BG3 Natural shape, dark green color (91) Bright apricot yellow (92) Noble, with a floral scent (91) Pure and refreshing (92) Even (91) 91.4 CK3-1 Curved, dark green in color (89) Green and yellow are still bright (88) Green air (85) Slightly green (89) Miscellaneous (87) 87.7

[0093] In addition, the quality of tea leaves in groups BG3 and CK3-1 to 3 was physically and chemically identified. The identification results are shown in the following table.

[0094] Group Tea polyphenols / % Amino Acid / % Soluble sugar / % Caffeine / % BG1 23.5 4.2 3.4 4.4 CK1-1 22.3 3.6 2.7 4.8 CK1-2 23.2 3.2 2.4 5.2 CK1-3 22.6 3.4 2.5 4.9

[0095] Combined with the above table, it can be seen that under the condition of similar water content, the tea polyphenols, free amino acids and soluble sugar content of the BG3 test group tea treated by the technical solution of the present invention are significantly increased compared with the CK3-1 test group tea, and the aminophenol ratio increases by 11%, which significantly improves the flavor quality of the overall tea. The EGCG content of each group was further characterized and tested, as shown in the following table.

[0096] Group BG3 CK3-1 CK3-2 CK3-3 EGCG / % 12.81 12.85 11.36 11.91

[0097] In the comparison between Example 2 and Comparative Example 2, it can be seen from the table above that although the total content of tea polyphenols is significantly increased after the laser light supplementation treatment of the present invention, the actual effective ingredient EGCG content is basically the same as that of the CK3-1 test group, higher than that of the CK3-2 and CK3-3 test groups, and the amino acid and soluble sugar content is also much higher than that of other groups. It can be seen that the laser light supplementation treatment of the present invention has a significant impact on the nutritional composition of tea leaves, so that not only the flavor quality of tea leaves is improved, but also the nutritional value quality is further improved. However, compared with the test group of Example 1, it can be seen that the single red light also has a relatively more significant improvement in flavor quality, but the effect of improving the actual nutritional value quality is not very significant.

[0098] However, a comprehensive comparison of Examples 1 to 3 and Comparative Examples 1 to 3 shows that the use of appropriate single red light and single blue light laser supplementary light to assist tea withering has a more significant effect on improving the flavor quality, especially in terms of aroma. When red and blue lasers are combined, the effect of improving the flavor quality is also more obvious, but the improvement in nutritional value quality is even better. When LED light is used for auxiliary withering, it is found that although the appropriate light intensity (about 380 to 450 μmol·m -2 ·s -1 ) can also assist withering, and compared with the conventional withering treatment without supplementary light, it has the effect of improving nutritional value, but compared with the sunlight group, it cannot significantly improve the nutritional value, and even slightly decreases it. Therefore, the current tea withering LED supplementary light solution is basically an alternative solution for rainy weather, rather than a mainstream solution, and has obvious limitations. However, for the technical solution of the present invention, the use of laser withering treatment can effectively produce significant improvements in both flavor quality and nutritional value quality.

[0099] Example 4

[0100] Based on the technical solution of Example 1, a control variable test was conducted on the overall fill light strategy.

[0101] The details are shown in the following table.

[0102] Group Specific laser light supplement strategy (660 nm red light and 450 nm blue light) BG1 <![CDATA[Red and blue light intensity ratio is 8:1, total laser light intensity is 0.8 μmol·m -2 ·s -1 > BG4-1 <![CDATA[Red to blue light intensity ratio is 6:1, total laser light intensity is 0.8 μmol·m -2 ·s -1 > BG4-2 <![CDATA[Red to blue light intensity ratio is 7:1, total laser light intensity is 0.8 μmol·m -2 ·s -1 > BG4-3 <![CDATA[Red to blue light intensity ratio is 9:1, total laser light intensity is 0.8 μmol·m -2 ·s -1 > BG4-4 <![CDATA[Red to blue light intensity ratio is 10:1, total laser light intensity is 0.8 μmol·m -2 ·s -1 > BG4-5 <![CDATA[Red and blue light intensity ratio 1:5, total laser light intensity 0.8 μmol·m -2 ·s -1 > BG4-6 <![CDATA[Red to blue light intensity ratio is 1:5, total laser light intensity is 1.2 μmol·m -2 ·s -1 > BG4-7 <![CDATA[Red to blue light intensity ratio is 1:5, total laser light intensity is 1.6 μmol·m -2 ·s -1 > BG4-8 <![CDATA[Red and blue light intensity ratio 1:5, total laser light intensity 2.0 μmol·m -2 ·s -1 > BG4-9 The red-blue light intensity ratio is 1:3, and the total laser intensity is 1.6 μmol·m-2·s-1 BG4-10 The red-blue light intensity ratio is 1:4, and the total laser intensity is 1.6 μmol·m-2·s-1 BG4-11 The ratio of red to blue light intensity is 1:6, and the total laser light intensity is 1.6 μmol·m-2·s-1 BG4-12 The red-blue light intensity ratio is 1:7, and the total laser light intensity is 1.6 μmol·m-2·s-1

[0103] The nutritional value of each group was analyzed and the results are shown in the following table.

[0104] Group EGCG / % Amino Acid / % Soluble sugar / % BG1 7.03 4.60 2.9 BG4-1 6.58 4.25 2.57 BG4-2 6.78 4.39 2.82 BG4-3 6.85 4.35 2.78 BG4-4 6.64 4.22 2.54 BG4-5 6.32 4.20 2.53 BG4-6 6.70 4.68 2.89 BG4-7 6.74 4.78 2.93 BG4-8 6.67 4.50 2.81 BG4-9 6.37 4.29 2.63 BG4-10 6.61 4.52 2.82 BG4-11 6.75 4.66 2.86 BG4-12 6.32 4.26 2.67

[0105] As can be seen from the table above, compared with monochromatic laser, the synergistic combination of red and blue lasers can significantly improve the nutritional value and quality of tea. There is a certain correlation between the light intensity ratio of red and blue light and the total light intensity. For example, when the red light ratio is high, a lower total light intensity should be used, which can significantly improve the content of catechins (EGCG). When the blue light is strong, the total light intensity can be increased to 1.2-2.0 μmol·m-2·s-1. Under this condition, the technical solution of the present invention significantly improves the amino acid content in tea, and the overall taste and flavor are better.

Claims

1. A tea spreading / withering method, characterized in that: The method comprises: A laser light field is set up at the tea leaf spreading / withering site, and laser treatment is performed when the tea leaves are spread / withering; The laser treatment uses a blue laser light source with a wavelength of 435 to 455 nm and a red laser light source with a wavelength of 645 to 665 nm. When the blue laser and the red laser are used together, the red-blue light intensity ratio is controlled to be 0.2 to 9:1, and the total light intensity is 0.1 to 5.0 μmol·m -2 ·s -1 , or using a light intensity of 0.1 μmol·m -2 ·s -1 , a blue laser with a wavelength of 435 nm, or a light intensity of 5.0 μmol·m -2 ·s -1 , red laser with a wavelength of 645 nm; The laser treatment duration is ≥ 1 h; The method is used to increase the aminophenol ratio of tea leaves after withering; During the treatment process of the method, laser is used to promote the rapid photosynthesis of fresh tea leaves to synthesize sugars and amino acids.

2. A tea spreading / withering method according to claim 1, characterized in that: The laser light source of the laser light field irradiates the fresh tea leaves in a top illumination, side illumination and / or oblique illumination manner.

3. A tea spreading / withering method according to claim 2, characterized in that: The laser light source is arranged at a distance of ≥0.5 m from the fresh tea leaves.

4. A tea spreading / withering method according to claim 1, characterized in that: The laser light source is a semiconductor laser light source.