Preparation method of honeysuckle green tea

Abstract

The invention discloses a preparation method of honeysuckle green tea, which comprises the following steps: (1) picking and maintaining flowers: picking flower buds in a big white stage or a second white stage and flowers in a flowering stage as raw materials, spreading thinly, ventilating and placing; (2) preparing a tea picking fresh tea leaves with one bud and two leaves or one bud and three leaves, and performing rolling, fixation and drying treatment to prepare the green tea base with the water content of 3-5%; (3) alternate filling: taking the honeysuckle and the green tea base in proportion, and alternately putting the honeysuckle and the green tea base into a tray layer by layer; (4) scenting and aroma enhancing: putting the filled multi-layer stacked tray into a scenting box; (5) drying and water control: independently taking the tea base for high-temperature drying, and cooling after drying; and (6) jacquard storage: uniformly stacking and boxing the tea bases, placing a small amount of honeysuckle in the tea bases, and statically jacquard to obtain a honeysuckle green tea sample. Compared with the traditional scented tea, the honeysuckle green tea product prepared by the invention has the advantages of compact tea appearance, emerald green color, strong flower fragrance, transparent and bright soup color and mellow taste.

Description

Technical Field

[0001] The invention relates to the technical field of green tea preparation, in particular to a method for preparing honeysuckle green tea. Background Art

[0002] The 2020 edition of the Pharmacopoeia stipulates that honeysuckle is the dried buds or flowers with early blooms of the Caprifoliaceae plant Lonicerajaponica Thunb, which has the effects of clearing away heat and detoxifying, and evacuating wind-heat. In 2014, it was included in the "List of Chinese Medicinal Materials with Medicinal and Edible Origins" and is often used as a food ingredient. The current preparation of honeysuckle tea mainly involves mixing honeysuckle buds and tea leaves, and implementing processes such as co-withering or co-fermentation to prepare honeysuckle fermented tea. The types of tea mentioned are mostly fermented or semi-fermented teas such as black tea, dark tea and oolong tea, and there is less content related to honeysuckle green tea.

[0003] Existing honeysuckle green tea is mainly divided into two contents. One is to learn from the green tea processing method, apply the relevant technology to honeysuckle buds, and prepare pure honeysuckle substitute tea, such as Chinese patents CN 01108675.0 and CN 201410539746.X; the other is to mix honeysuckle and green tea to prepare related scented tea, such as Chinese patent CN 201810503904.4. In Chinese patent CN2018105003904.4, the main raw materials of the prepared honeysuckle green tea are dry tea leaves and honeysuckle buds. The honeysuckle used includes honeysuckle buds and flowers, in which the flowers and tea leaves are stacked in layers to enhance the fragrance, the buds are dried by mechanical steaming, and the buds and tea leaves are mixed to obtain tea samples. The interlayer stacking process needs to be repeated 5 to 9 times, and the amount of flowers used is large. The cost of mechanical steaming is relatively high, and the overall operation is relatively complicated. The purpose of the patent focuses on solving the problem of unstable chlorogenic acid content after honeysuckle processing, but lacks in-depth research on the process of blending tea samples and floral fragrance, and the degree of fusion of the honeysuckle tea aroma is not significant.

[0004] Therefore, a method for preparing honeysuckle green tea with simple operation, simple process and low cost is needed, which can prepare honeysuckle green tea with high camellia aroma fusion and good tea quality. Summary of the invention

[0005] Aiming at the problems that the existing preparation method of honeysuckle green tea has complex operation, high cost, unobvious fusion of camellia aroma, poor tea quality, etc., the invention proposes honeysuckle green tea and a preparation method.

[0006] The honeysuckle green tea and preparation method thereof comprise the following steps:

[0007] S1. Flower picking and maintenance: Pick the flower buds in the big white stage or the second white stage and the flowers in the silver flower stage as raw materials, spread them thinly and place them in a ventilated place;

[0008] S2, tea slab preparation: picking fresh tea leaves with one bud and two leaves or one bud and three leaves, and making green tea slabs with a water content of 3% to 5% through rolling, withering and drying;

[0009] S3, alternate filling: take the honeysuckle in S1 and the green tea in S2 in proportion, and put them into the tray alternately layer by layer;

[0010] S4, scenting and aroma preparation: placing the multi-layer stacked trays loaded in S3 into a scenting box, which has a circulating airflow passage from bottom to top, and uses the circulating airflow for cooling; configuring the box temperature and airflow velocity, and implementing the separate scenting and aroma preparation process;

[0011] S5, drying and water control: take the tea leaves from S4 and dry them at high temperature, the drying temperature is 50-70°C, and the drying time is 10-15 minutes; after drying, cool the tea leaves to control the water content of the tea leaves to ≤5%;

[0012] S6, jacquard storage: evenly pile the tea leaves in S5 into boxes, put a small amount of honeysuckle in S1 into the boxes, perform static jacquard to obtain honeysuckle green tea sample, and store at low temperature in a refrigerator at 0-4℃.

[0013] In a preferred embodiment of the present invention, the thin spreading thickness in S1 is ≤3 cm, the time is 4 to 6 hours, and it is not turned over.

[0014] In a preferred embodiment of the present invention, the tray in S3 is a combination of PET mesh and wooden structure, and the honeysuckle tray is covered with medical gauze; each layer of the trays is stacked directly without leaving any gaps, and the top and bottom layers are both tea base layers, the number of tea base layers is 3 to 6 layers, and the corresponding honeysuckle layers are 2 to 5 layers.

[0015] Furthermore, the stacking thickness of the tea leaves and honeysuckle is ≤3 cm, and the mass ratio of honeysuckle to tea leaves is 1:5.

[0016] In a preferred embodiment of the present invention, the box temperature in S4 is ≤25°C, the air flow rate is 1-2 m / s, and the scenting time is 10-12 h.

[0017] Furthermore, the mass ratio of honeysuckle to tea leaves in S6 is 1:50.

[0018] In a preferred embodiment of the present invention, the final water content of the honeysuckle green tea sample obtained in S6 is ≤8%.

[0019] Furthermore, the operations from S3 to S6 are all carried out in a cool, shaded place with an ambient temperature of ≤25°C to maintain long-term stability.

[0020] Implementing the embodiments of the present invention has the following beneficial effects:

[0021] The invention adopts a camellia separation scenting method and uses medical gauze as a cushion layer, which has the advantages of: firstly, the separation scenting can avoid large-scale contact of camellia, which would cause the green tea base to deteriorate due to excessive water absorption; secondly, the medical gauze cushion layer is used to effectively absorb the moisture of the honeysuckle flowers, and at the same time, the air permeability of the gauze can promote the full play of the honeysuckle fragrance, and finally separate the honeysuckle fragrance and moisture; thirdly, the anthers and filaments in the honeysuckle flowers are small, similar in size to tea leaves, and it is difficult to achieve complete separation from the tea leaves. The separation scenting method can achieve simple and effective separation of honeysuckle and tea base, so that there is no flower in the tea and no tea in the flower, which is beneficial to subsequent processing.

[0022] Streamlined preparation process: The present invention simplifies the process by removing the flower-raising and flower-picking processes through separate scenting, extraction and storage, reducing the need for configuration of related equipment such as screens, and shortening the traditional preparation process of "scenting → flower-picking → drying → flower-picking → storage" to "scenting → drying → storage", effectively streamlining the scented tea preparation process and shortening the scented tea production cycle.

[0023] Reduced flower cost: The present invention adopts a multi-layer three-dimensional stacking structure for scenting. The alternately filled green tea and honeysuckle trays are directly stacked to form a nearly closed scenting space, which is conducive to the full dissipation of the flower fragrance into the tea leaves. Compared with the conventional mixing scenting, the amount of flowers added in a single production cycle is small, the utilization efficiency of the flower fragrance is high, and the cost of flowers is effectively reduced.

[0024] The production cost is reduced: the present invention only uses wooden pallets, medical gauze and other materials in the preparation of honeysuckle green tea. Compared with commonly used steam equipment, microwave equipment and other equipment, the material cost is low and easy to obtain.

[0025] The product preserves color and enhances aroma: the present invention preserves color, enhances aroma and flavor of green tea through a simple preparation method. The obtained green tea has a tight appearance, emerald green color, rich and lasting floral aroma, clear soup color, and fresh and mellow taste with floral aroma. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a multi-layer three-dimensional stacked structure;

[0028] Figure 2 The tea soup and dry tea of ​​Comparative Example 1;

[0029] Figure 3 The tea soup and dry tea of ​​Example 1;

[0030] Figure 4 The tea soup and dry tea of ​​Example 2;

[0031] Figure 5 The tea soup and dry tea of ​​Example 3;

[0032] In the figure: a wooden frame 1, a tea layer 2, a PET mesh and medical gauze 3, a PET mesh 4 and a honeysuckle layer 5. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The preparation method of the honeysuckle green tea comprises the following steps:

[0035] S1. Flower collection and maintenance: Pick flower buds in the big white stage or the second white stage and flowers in the silver flower stage as raw materials, spread them thinly and place them in a ventilated place; the thickness of the thin spread should be ≤3cm, and the time should be 4 to 6 hours, and do not turn them over.

[0036] The flowering period of honeysuckle is divided into three green stages, two white stages, big white stages, silver flower stages and golden flower stages, which is about 15 days. It usually blooms in early May, and the flowering period changes rapidly. The content of chlorogenic acid in honeysuckle is higher in the three green stages to the big white stages, and the content of luteolin is higher in the two white stages to the silver flower stages. Considering comprehensively, the flower buds in the big white stage or the two white stage and the flowers in the silver flower stage are selected as raw materials. When the honeysuckle buds turn from green to white, it means that they will enter the two white stage and can be harvested. The harvesting time is generally selected before 10 am on a non-rainy day and avoid sun exposure. When the honeysuckle is moist with dew, it is picked to ensure that the flower has sufficient fragrance and high content of effective components. A ventilated bamboo basket should be selected for picking, and it should be placed in a cool, shaded and ventilated place in time after picking. Spread the fresh honeysuckle thinly on the bamboo mat, with a thickness of ≤3cm, for 4 to 6 hours, and do not turn it over to avoid oxidation and blackening of the honeysuckle due to turning over, which will reduce the quality.

[0037] S2. Tea base production: fresh tea leaves with one bud and two leaves or one bud and three leaves are picked, and processed by rolling, withering and drying to produce green tea base with a moisture content of 3% to 5%.

[0038] S3. Alternating loading: Take the honeysuckle in S1 and the green tea blanks in S2 in proportion, and put them into the tray alternately layer by layer; the honeysuckle tray is covered with medical gauze; the trays are stacked directly without leaving any gaps, and the top and bottom layers are both tea blank layers, the number of tea blank layers is 3 to 6 layers, and the corresponding honeysuckle layers are 2 to 5 layers; the stacking thickness of tea blanks and honeysuckle is ≤3 cm, and the mass ratio of honeysuckle to tea blanks is 1:5.

[0039] The tray is a combination of PET mesh and wooden structure to avoid the oxidation and blackening of honeysuckle caused by the use of metal and other material trays. The honeysuckle tray is filled with medical gauze to absorb moisture from the honeysuckle. Medical gauze is absorbent cotton that has been dried at high temperature. It meets food standards, has good air permeability, strong water absorption, and will not drop floating cotton yarn fibers, which will affect the quality of honeysuckle and tea. Each layer of trays is stacked directly without leaving gaps. The top and bottom layers are both tea layers. The number of tea layers is 3 to 6 layers, and the number of honeysuckle layers is 2 to 5 layers. The overall multi-layer three-dimensional stacking structure is constructed to form a nearly closed scenting space to promote the full dissipation of floral fragrance. The stacking thickness of tea and honeysuckle is ≤3cm, and the ratio of honeysuckle to tea blank is 1:5.

[0040] See also Figure 1 , Figure 1 It is a multi-layer three-dimensional stacked structure. The reason for adopting a multi-layer structure: the fragrance of honeysuckle is fresh and fragrant, but compared with other flowers such as jasmine and osmanthus, the fragrance of honeysuckle flowers is lighter. In addition, the fragrance of honeysuckle flowers only exists in fresh flowers, and dried flowers that have been dried or stored for a long time have basically no fragrance.

[0041] The light fragrance of honeysuckle means that when preparing honeysuckle green tea, a large amount of honeysuckle is required to achieve a fragrance level similar to that of other scented teas. The conventional scenting process is to mix fresh flowers and tea leaves evenly and place them together to enhance the fragrance. If the conventional scenting method is used, the water content of large quantities of honeysuckle is high, which can easily cause the green tea base to absorb too much water and deteriorate, affecting the quality of tea leaves and scented tea.

[0042] Therefore, a method is now needed to prevent the water from the honeysuckle flowers from contaminating the tea leaves and to improve the utilization rate of the honeysuckle aroma.

[0043] Composition of multi-layer structure: multi-layer three-dimensional stacking structure, composed of stacking pallets. The pallets are round or square, fixed with wooden frames on all sides, and supported by PET mesh in the middle.

[0044] The principle of the multi-layer structure: tea leaves are placed on the top and bottom layers of the tray, and the middle layer is alternately stacked with honeysuckle and tea leaves. The wooden racks around the tray can be stacked together. The wooden racks and the top and bottom tea leaves are used to achieve the overall closed nature of the multi-layer structure, so that the aroma of honeysuckle can be fully dissipated in a closed environment and absorbed and retained by the tea leaves.

[0045] In order to reduce the environmental humidity of the overall structure, medical absorbent cotton gauze is laid inside the honeysuckle layer to fully absorb the moisture of the honeysuckle flowers. At the same time, the permeability of the gauze grid is used to promote the dissipation of the aroma.

[0046] Advantages of multi-layer structure: Advantages of absorbent cotton gauze material: Compared with conventional mesh materials such as PET, nylon, and steel wire, absorbent cotton gauze has the advantage of strong water absorption; compared with conventional cloth, mesh, pure cotton gauze and other absorbent materials, absorbent cotton gauze has the advantages of not shedding cotton hair and mesh breathability.

[0047] The conventional scenting method is to mix the flowers and tea evenly, and then place them in a closed scenting box for scenting. The defects are that, first, long-term storage can easily cause the scented tea to accumulate and generate heat, and second, the amount of flowers is affected by the water content. Therefore, during the scenting process, the box needs to be opened and stirred, and the flowers need to be vented to dissipate heat before being piled up for scenting again. The number of flowers needs to be limited to prevent the tea from absorbing too much water. The advantages of the multi-layer structure are that, first, a separate scenting method is used to separate the amount of flowers and water content of the honeysuckle flowers; second, a closed scenting environment is constructed to reduce the probability of the honeysuckle fragrance escaping from the scenting environment during Brownian motion; third, absorbent cotton gauze is used to absorb the moisture of the honeysuckle to reduce the impact of the moisture in the flowers on the environmental humidity.

[0048] The correlation between the multi-layer structure and the scenting box: The multi-layer structure is a separate closed structure, similar to building a small closed scenting structure, to achieve closed scenting of flowers and tea leaves. The scenting box is equipped with an airflow channel, which uses the ventilation airflow from bottom to top to take away the heat generated during the scenting of the flower tea, and is used to cool the internal environment.

[0049] The multi-layer structure is placed in a scenting box, and the flowers and tea leaves are scented separately using the multi-layer structure. Absorbent cotton gauze is used to absorb excess moisture and control the ambient humidity. The ambient temperature is controlled using the airflow in the scenting box. This achieves low-cost control of ambient temperature and humidity as a whole, while utilizing the adsorption properties of tea leaves to efficiently absorb and retain the aroma of honeysuckle.

[0050] Process optimization achieved by the separate scenting process: The separate scenting of tea flowers is achieved by adopting a multi-layer structure. This process has achieved the separation of tea flowers, temperature and humidity control, which makes the conventional "scenting → flower picking → drying" process can be simplified to "scenting → drying". (Note: "flower picking" means screening flowers, that is, separating flowers and tea leaves through a sieve)

[0051] In the conventional drying process, high temperatures above 100°C are often used to dehumidify the tea leaves, and high-quality flowers are subsequently used for the weaving process to enhance the fragrance of the scented tea. Since the aroma of honeysuckle is relatively light, in order to avoid the disappearance of the fragrance due to high-temperature drying, this process uses 50-70°C for drying and dehumidification, and a small amount of honeysuckle is subsequently used for aroma enhancement during storage. This simplifies the conventional "drying → weaving → storage" process into a "drying → storage" process.

[0052] S4, scenting and aroma enhancement: Place the multi-layer stacked trays filled in S3 into the scenting box, which has a circulating airflow passage from bottom to top, so that the low-temperature airflow is blown in from the bottom of the box and sucked out from the top, and circulated repeatedly, and the circulating airflow is used to cool the box. Configure the box temperature and airflow velocity, and implement the separate scenting and aroma enhancement process. The box temperature is ≤25℃, and a low room temperature environment is maintained during scenting to avoid high-temperature loss and high-speed escape of honeysuckle aroma components. The airflow velocity is 1-2m / s, and the scenting time is 10-12h.

[0053] S5, drying and water control: Take the tea leaves from S4 and dry them at high temperature, the drying temperature is 50-70℃, and the drying time is 10-15min; after drying, cool the tea leaves and control the water content to ≤5%; the drying process helps to remove excess water, facilitate the better fusion of tea leaves and flower fragrance, and maintain the quality of flower tea. The water content of the tea leaves is controlled at 5% or less because flowers will be added in the subsequent storage process, which makes the tea leaves absorb water, resulting in a slight increase in water content.

[0054] S6, jacquard storage: evenly pile the tea leaves in S5 and put a small amount of honeysuckle in S1 into the box, with the mass ratio of honeysuckle to tea leaves being 1:50, and perform static jacquard so that the floral fragrance in the enclosed space can be fully dispersed into the tea leaves. Store at low temperature in a refrigerator at 0-4℃ to prevent the tea sample from getting damp and deteriorating, and obtain a honeysuckle green tea sample. Control the final moisture content of the mixed tea leaves of honeysuckle and green tea to ≤8%.

[0055] The operations from S3 to S6 are all carried out in a cool and shaded place to avoid exposure to the sun, which may cause the honeysuckle to lose too much water, oxidize and turn black, and reduce the effective ingredients; the chlorophyll in the tea leaves will decompose faster, causing browning, and ultimately reducing the quality of the scented tea. The ambient temperature should be ≤25℃ and remain stable for a long time.

[0056] Compared with traditional scented tea, the honeysuckle green tea product prepared by the invention has compact tea leaves, emerald green color, strong floral fragrance, bright soup color and mellow taste. Specific embodiments

[0058] 1. Test methods

[0059] 1. Test grouping: The specific test group is divided into 4 groups, namely (1) Comparative Example 1: ordinary scented tea sample, without honeysuckle; (2) Example 1: separate scented tea sample, using the above-mentioned small amount of jacquard method; (3) Example 2: conventional mixing scented tea sample, other steps are the same as Example 1; (4) Example 3: separate scented tea sample, using conventional mixing scented proportions for jacquard. Detailed settings are shown in Table 1 below.

[0060] Table 1 Comparison table of examples and comparative examples

[0061]

[0062] 2. Test method: After storage, tea samples were obtained from each embodiment and comparative example. Tea leaves from each example were brewed with boiling water according to conventional methods to obtain tea soup.

[0063] 2. Test results

[0064] The test results of tea samples, soup color, etc. of the three embodiments and one comparative example were compared, and it was found that embodiment 1 was the best embodiment. Compared with comparative example 1, the tea sample of embodiment 1 was emerald green in color, with a strong floral fragrance when smelled up close, and the tea leaves were tightly rubbed by hand; the tea soup of embodiment 1 was clear and bright, without turbidity, mellow in taste, long aftertaste, and strong honeysuckle aroma. The tea sample of embodiment 2 had slightly curled tea leaves, dark yellow in color, and light floral fragrance, which was mostly due to the fact that a large amount of honeysuckle flowers were used in the conventional mixing and scenting process, causing the tea leaves to absorb water and deteriorate, thereby affecting the efficiency of floral fragrance adsorption; the tea soup of embodiment 2 had a darker soup color, was slightly turbid, had a more astringent taste, and did not have a strong honeysuckle aroma. The tea samples of Example 3 are mostly curled in appearance, with a yellow-green color and a strong floral fragrance. The reason for this is that a large amount of honeysuckle flowers are used in the jacquard process, causing the tea leaves to absorb water and deteriorate. The tea soup of Example 3 is dark and turbid in color, has a green taste, and has a certain honeysuckle aroma. The reason for this is that the honeysuckle flowers cannot be completely separated from the tea leaves, and fine substances such as anthers in some flowers are adsorbed on the tea leaves, affecting the taste of the brewed tea soup.

[0065] By comparing the three examples, it can be found that Example 1 effectively separates the honeysuckle aroma and water, so that the tea leaves can absorb the honeysuckle aroma to a large extent without causing water absorption and deterioration, and finally produce honeysuckle green tea with a high degree of tea aroma fusion. The specific test results are shown in Table 2 below.

[0066] Table 2 Test results comparison table

[0067]

[0068] See also Figure 2-5 , Figure 2 The tea soup and dry tea of ​​Comparative Example 1; Figure 3 The tea soup and dry tea of ​​Example 1; Figure 4 The tea soup and dry tea of ​​Example 2; Figure 5 The tea soup and dry tea of ​​Example 3.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing honeysuckle green tea, characterized in that: The following steps are involved: S1. Flower picking and maintenance: Pick the flower buds in the big white stage or the second white stage and the flowers in the silver flower stage as raw materials, spread them thinly and place them in a ventilated place; S2, tea slab preparation: picking fresh tea leaves with one bud and two leaves or one bud and three leaves, and making green tea slabs with a water content of 3% to 5% through rolling, withering and drying; S3, alternate filling: take the honeysuckle in S1 and the green tea in S2 in proportion, and put them into the tray alternately layer by layer; S4, scenting and aroma preparation: placing the multi-layer stacked trays loaded in S3 into a scenting box, which has a circulating airflow passage from bottom to top, and uses the circulating airflow for cooling; configuring the box temperature and airflow velocity, and implementing the separate scenting and aroma preparation process; S5, drying and water control: take the tea leaves from S4 and dry them at high temperature, the drying temperature is 50-70°C, and the drying time is 10-15 minutes; after drying, cool the tea leaves to control the water content of the tea leaves to ≤5%; S6, jacquard storage: evenly pile the tea leaves in S5 into boxes, put a small amount of honeysuckle in S1 into the boxes, perform static jacquard to obtain honeysuckle green tea sample, and store at low temperature in a refrigerator at 0-4℃.

2. The method for preparing honeysuckle green tea according to claim 1, characterized in that: The thickness of the thin layer in S1 is ≤3cm, and the time is 4 to 6 hours. Do not stir.

3. The method for preparing honeysuckle green tea according to claim 1, characterized in that: The tray in S3 is a combination of PET mesh and wooden structure, and the honeysuckle tray is covered with medical gauze; each layer of trays is stacked directly without leaving any gaps, and the top and bottom layers are both tea base layers, the number of tea base layers is 3 to 6 layers, and the corresponding honeysuckle layers are 2 to 5 layers.

4. The method for preparing honeysuckle green tea according to claim 3, characterized in that: The stacking thickness of the tea leaves and honeysuckle is ≤3 cm, and the mass ratio of honeysuckle to tea leaves is 1:

5.

5. The method for preparing honeysuckle green tea according to claim 1, characterized in that: In the S4, the box temperature is ≤25°C, the air flow rate is 1-2m / s, and the scenting time is 10-12h.

6. The method for preparing honeysuckle green tea according to claim 1, characterized in that: The mass ratio of honeysuckle to tea leaves in S6 is 1:

50.

7. The method for preparing honeysuckle green tea according to claim 6, characterized in that: The final water content of the honeysuckle green tea sample obtained in S6 is ≤8%.

8. The method for preparing honeysuckle green tea according to any one of claims 1 to 7, characterized in that: The operations from S3 to S6 are all carried out in a cool, shaded place with an ambient temperature of ≤25°C to maintain long-term stability.

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