A Gastrodia elata processing method and application for directionally enhancing the content of gastrodin based on photo-assisted heat

Abstract

The present invention belongs to the technical field of biopharmaceutical empowered processing, and discloses a gastrodia elata processing method and application for directionally enhancing the content of gastrodin based on photo-assisted heat. The method includes the selection of gastrodia elata raw materials, cleaning, screening, slicing, secondary screening, and ultraviolet light-assisted hot air drying. The content of gastrodin in the gastrodia elata processed by the photo-assisted hot air drying technology of the present invention has significant advantages compared with that of sun-dried gastrodia elata, freeze-dried gastrodia elata, and single hot air drying at 150 °C for 3 h. The content of gastrodin reaches 20.28 mg / g, which is significantly higher than the standard that the total content of gastrodin and p-hydroxybenzyl alcohol in the Chinese Pharmacopoeia shall not be less than 2.5 mg / g, providing a theoretical basis and technical support for the economic value and empowerment of gastrodia elata.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical empowered processing, and in particular, to a gastrodia elata processing method and application for enhancing the content of gastrodin based on light-assisted heat orientation. Background Technique

[0002] Gastrodia elata is a plant of the genus Gastrodia in the Orchidaceae family. It has a medicinal history of more than two thousand years in China. In 2019, it was included in the catalog of both medicine and food homologues. Gastrodia elata has various pharmacological effects such as anti-convulsion, sedative-hypnotic, analgesic, promoting intelligence and anti-aging, blood pressure lowering, improving blood supply, and neuroprotection. The beneficial effects of gastrodia elata are mainly due to its rich phenolic substances, such as gastrodin, p-hydroxybenzyl alcohol, and parishin glycosides. Among them, gastrodin is designated as the quality control component by the Chinese Pharmacopoeia (2020 edition) and is an important indicator for evaluating the quality of gastrodia elata.

[0003] Gastrodin belongs to the single-benzyl class of aromatic compounds, which consists of an aromatic core and a sugar moiety connected by a glycosidic bond. Its chemical structural formula is shown as (A) below. As the most abundant effective monomer component in gastrodia elata, gastrodin exerts its sedative-hypnotic effect by balancing the release of neurotransmitters, reducing the expression of inflammatory factors, improving the function of the hypothalamic-pituitary-adrenal axis, and increasing the abundance of gut microbiota. The chemical structural formula of p-hydroxybenzyl alcohol is shown as (B) below. Compared with gastrodin, it lacks a glucose group and is the aglycone formed by the hydrolysis of gastrodin. By regulating the balance between excitation and inhibition of the cerebral cortex, it not only has a good effect on improving learning and memory function disorders but also has a repair and protection effect on nervous system damage. The phenolic glycoside compounds in gastrodia elata mainly exist in the form of parishin glycosides, which are formed by one molecule of citric acid linked to different amounts of gastrodin. They are classified and named according to the position and number of ester bonds between gastrodin and citric acid, such as parishin A, B, C, and E. Parishin has thermal instability, and during heating, the ester bond is prone to breakage, resulting in the interconversion and migration between parishin glycoside compounds or between them and gastrodin and p-hydroxybenzyl alcohol. As shown in the hydrolysis process (C) of parishin A, under heating conditions, parishin A can be acid-hydrolyzed to obtain gastrodin and parishin B, C, and G. Further hydrolysis can obtain gastrodin and parishin E, and finally hydrolysis can obtain gastrodin and p-hydroxybenzyl alcohol.

[0004]

[0005] Among them, the molecular structural formulas of gastrodin (A), p-hydroxybenzyl alcohol (B), the hydrolysis process of parishin A (C), and the biosynthetic pathway of gastrodin (D). Note: Glc: glucose group; GAS: gastrodin; HBA: p-hydroxybenzyl alcohol; UDP-Glc: uridine diphosphate glucose; UDP: uridine diphosphate.

[0006] Pharmacopoeia of the People's Republic of China (2020 Edition) stipulates that, calculated on the dried product (with water content not exceeding 15.0%), the total amount of gastrodin and p-hydroxybenzyl alcohol in Gastrodia elata should not be less than 2.5 mg / g. However, the growth and quality of Gastrodia elata are affected by factors such as climate, soil, terrain, temperature, and humidity. The contents of gastrodin and p-hydroxybenzyl alcohol in fresh Gastrodia elata are relatively low, and even some of them do not meet the requirements of the Chinese Pharmacopoeia. Their contents will continue to decrease with the extension of storage time. Research shows that the processing process after harvesting plays a key role in retaining and increasing the contents of gastrodin and p-hydroxybenzyl alcohol. The traditional drying method of Gastrodia elata requires steaming before drying in the sun for 3-4 days. During the steaming process, the non-covalent interaction between Gastrodia elata starch and polyphenols may be destroyed, affecting its stability and nutritional value during processing and storage. In addition, boiling treatment may cause quality loss, with problems such as complex operation, long production cycle, and low retention rate of active ingredients. In order to improve the content of active ingredients and production efficiency after processing Gastrodia elata, the urgent problem to be solved is to adopt a convenient drying method to retain the content of gastrodin in Gastrodia elata while maximizing the conversion of p-hydroxybenzyl alcohol and parishin glycosides into gastrodin, further improving the quality and processing efficiency of Gastrodia elata.

[0007] Specifically, the technical problems existing in the prior art are as follows: (1) The content of gastrodin in fresh Gastrodia elata is insufficient, and even some of them do not meet the requirements of the Chinese Pharmacopoeia. Its content will continue to decrease with the extension of the storage time of Gastrodia elata, with the risk of being lower than the drug quality standard. (2) The traditional processing technology level is low, the processing cycle is long, and quality control is difficult. Some innovative methods have relatively high costs and are difficult to be industrialized and popularized.

[0008] Through retrieval, the following several patent publication documents related to this invention patent application are found:

[0009] 1. Most of the Gastrodia elata tablets currently on the market have different levels of processing complexity. They need to be soaked and steamed, which can easily reduce their medicinal effects and greatly increase their production costs. The Chinese patent publication "A Drying Method for Gastrodia elata Tablets (CN110478438A)" provides a processing method for Gastrodia elata tablets, including the following steps: First, harvest the newly grown Gastrodia elata of the current year, select Gastrodia elata with uniform shape and moderate size, weighing 180 - 220 g. Second, first wash the soil on the outer skin with warm water, cut off the head and tail of the washed Gastrodia elata, and then make a transverse cut of the Gastrodia elata. The thickness of the Gastrodia elata slices is 1.5 mm - 3 mm. The sliced Gastrodia elata tablets are naturally dried for 5 - 8 h, and then the dried Gastrodia elata tablets are soaked in honey water for 1 - 2 h. Third, hang the honey-soaked Gastrodia elata tablets in a drying oven, then fill the drying oven with inert gas, and then adopt a closed-loop drying method. The drying duration is 48 - 60 h. The drying is carried out in two stages. The first 30 h is the first drying stage. The drying temperature in the drying oven during the first drying stage is 40℃ - 60℃. After the first drying for 2 h, drying ventilation is carried out, and then ventilation and air exchange are carried out every 5 h. Then enter the second drying stage. The drying temperature in the drying oven during the second drying stage is 30℃ - 40℃. Ventilation is carried out every 8 h of drying. After drying is completed, take out the Gastrodia elata tablets.

[0010] The existing problems are: (1) Natural drying is required in this method, which may introduce impurities. (2) This processing method for Gastrodia elata tablets is too cumbersome and has a high time cost, which limits the large-scale processing and production of Gastrodia elata. (3) Adding honey during the processing may have side effects on diabetic patients, liver cirrhosis patients, and hypoglycemic people, reducing the audience of Gastrodia elata tablets.

[0011] 2. Aiming at the problem that the content of gastrodin and p-hydroxybenzyl alcohol in Gastrodia elata processed under the traditional processing technology is insufficient and there is a risk of being lower than the drug quality standard, the Chinese patent publication "A Microwave Hot Air Drying Method for Gastrodia elata (CN110638941A)" provides a processing method for Gastrodia elata, including the following steps: First, wash the outer skin of fresh, plump and moderately sized Gastrodia elata from Yunnan Zhaotong clean. Second, put it into a water bath pot and steam it. The steaming temperature is 80 - 100℃, and the steaming time is 10 - 15 min. Third, after steaming, let it be naturally dried for 1 - 3 h to room temperature. After cooling, cut the Gastrodia elata into slices with a thickness of 3 - 5 mm. After slicing, evenly spread the cut Gastrodia elata on a tray. Fourth, put it into a microwave drying oven with a power of 200 W - 400 W, a hot air temperature of 40 - 60℃, a drying time of 15 - 25 min, and a microwave frequency of 2000 - 3000 MHz. After drying is completed, carry out vacuum packaging.

[0012] The existing problems are as follows: (1) A significant drawback of microwave drying in this method is its inherent non-uniform heating, which may lead to local overheating and charring; (2) This method requires natural drying after steaming. The main problem is that natural drying is greatly affected by external factors, the drying time is not fixed, and the product uniformity is poor.

[0013] In contrast, the present invention is essentially different from the above-mentioned patent disclosure documents. The method of the present invention is a drying process for processing Gastrodia elata to increase the content of gastrodin by precisely controlling the temperature and time of ultraviolet light irradiation combined with hot air drying. First, by controlling different drying temperatures and times, the drying parameters that can maximize the content of gastrodin are determined, and then, combined with the characteristics of strong penetration and high photochemical activity of ultraviolet light, the content of gastrodin in Gastrodia elata is further increased. As shown in the biosynthetic pathway (D) of gastrodin, the selective homolytic cleavage of the pyrophosphate bond in UDP-glucose is initiated by ultraviolet light to generate glucose radicals, which then undergo an O-glycosylation reaction with p-hydroxybenzyl alcohol, promoting the conversion of p-hydroxybenzyl alcohol in Gastrodia elata to gastrodin, thereby increasing the content of gastrodin in Gastrodia elata. By precisely controlling the drying temperature and time and combining ultraviolet light curing, the processing flow of the method of the present invention is as Figure 1 shown, providing an efficient, safe, and economical method for processing Gastrodia elata, and at the same time providing a processing method for subsequent optimal extraction of gastrodin components in Gastrodia elata, greatly improving the medicinal value of Gastrodia elata. Summary of the Invention

[0014] The object of the present invention is to overcome the deficiencies in the prior art and provide a method for processing Gastrodia elata based on photo-assisted heat-directed enhancement of gastrodin content and its application.

[0015] The technical solution adopted by the present invention to solve its technical problems is:

[0016] A method for processing Gastrodia elata based on photo-assisted heat-directed enhancement of gastrodin content, the method comprising selecting Gastrodia elata raw materials, washing, screening, slicing, secondary screening, and ultraviolet light-assisted hot air drying.

[0017] Furthermore, it includes the following steps:

[0018] (1) Slicing: Cut Gastrodia elata into round thin slices with a thickness of 3 - 4.5 mm;

[0019] (2) Photo-assisted hot air drying: Continuously assist hot air drying with ultraviolet light of 750 - 952 THz, 315 - 400 nm to obtain the finished product;

[0020] The hot air drying conditions are: drying at 90 - 160 °C for 1 - 5 h.

[0021] Furthermore, the specific steps are as follows:

[0022] 1) Fruit selection: Select Gastrodia elata fruits, with a weight of 120 - 140 g per fruit;

[0023] 2) Cleaning: Clean the soil on the surface of Gastrodia elata with running water;

[0024] 3) Screening: After cleaning, screen out Gastrodia elata fruits with mildew spots or rot found after cleaning;

[0025] 4) Slicing: Transversely cut Gastrodia elata into slices with a thickness of 3 - 4.5 mm;

[0026] 5) Secondary screening: Conduct secondary screening on the slices, and select thin Gastrodia elata slices without pests and without hollow hearts;

[0027] 6) Light-assisted hot air drying: Take 15 - 20 g of thin Gastrodia elata slices and place them on a tray, put them into a hot air drying oven, and under the condition of uniform and continuous stimulation of ultraviolet light at 750 - 952 THz and 315 - 400 nm, adjust the hot air drying temperature to 90 - 160 °C and dry for 1 - 5 h. The humidity of the drying environment is not controlled to obtain the finished product.

[0028] 7) Dehumidifying packaging and sterilizing storage.

[0029] Furthermore, the Gastrodia elata fruits are fresh, without rot, pests, mildew spots, with uniform body shape and appropriate size.

[0030] Furthermore, use a slicing machine to transversely cut Gastrodia elata into slices with a thickness of 3 - 4.5 mm.

[0031] Furthermore, the ultraviolet light is ultraviolet light at 769 THz and 390 nm.

[0032] Furthermore, the hot air drying temperature is 150 °C and dry for 3 h.

[0033] Application of the Gastrodia elata processing method as described above in increasing the content of gastrodin in Gastrodia elata.

[0034] The advantages and positive effects obtained by the present invention are:

[0035] 1. The present invention adopts light-assisted hot air drying technology to conduct convenient ultra-high temperature processing on Gastrodia elata, which can not only greatly increase the content of gastrodin and exert its medicinal value, but also improve the drying efficiency, and at the same time can reduce unnecessary waste of energy.

[0036] 2. The content of gastrodin in gastrodia elata processed by the light-assisted hot air drying technology of the present invention has significant advantages compared with that of sun-dried gastrodia elata, freeze-dried gastrodia elata, and hot air drying alone at 150 °C for 3 h. The content of gastrodin reaches 20.28 mg / g, which is significantly higher than the standard that the total content of gastrodin and p-hydroxybenzyl alcohol in the Chinese Pharmacopoeia shall not be less than 2.5 mg / g, providing a theoretical basis and technical support for the economic value and empowerment of gastrodia elata.

[0037] 3. The light-assisted hot air drying technology of gastrodia elata in the present invention uses physical and photochemical methods to safely and greenly increase the content of gastrodin in gastrodia elata, with a doubled drying rate and simple quality control, suitable for large-scale production by enterprises.

[0038] 4. Using gastrodia elata processed by the light-assisted hot air drying technology of the present invention as a processing raw material, the subsequent processing cost is low and the safety is relatively high, and the product has high market competitiveness.

[0039] 5. The present invention relates to a processing technology for gastrodia elata, a food and drug homologous agricultural product. By directionally processing gastrodia elata, the content of its main medicinal ingredient, gastrodin, is increased. This method uses ultraviolet light-assisted hot air drying technology to reasonably configure parameters such as the drying temperature, time, and the frequency and wavelength of ultraviolet light, so that the content of gastrodin in gastrodia elata is maximally doubled while being retained.

[0040] 6. The present invention solves the problems of the long production cycle of the traditional sun-drying technology of gastrodia elata and the easy mixing of impurities and bacteria, and solves the problem of inappropriate control of the steaming time in the traditional process of steaming gastrodia elata first and then drying at low temperature. If the steaming time is insufficient, gastrodigenin in gastrodia elata cannot be effectively converted into gastrodin, and at the same time, the activity of β-glycosidase is retained, which accelerates the decomposition of gastrodin and leads to a decrease in the content of gastrodin; over-steaming will cause serious damage to the cells in gastrodia elata, resulting in the overflow of the contents, and the loss of some water-soluble components such as gastrodin, thus reducing the quality of gastrodia elata.

[0041] The method of the present invention is a convenient, accurate and directional processing method for increasing the content of gastrodin in gastrodia elata. It increases the drying rate of fresh gastrodia elata while also increasing the content of gastrodin, improves the quality of the processed gastrodia elata, shortens the production cycle of the traditional processing of gastrodia elata by solidifying first and then drying, and improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is the process flow chart of the precise processing of gastrodia elata in the present invention;

[0043] Figure 2 It is the standard curve graph of gastrodin in the present invention;

[0044] Figure 3This is the graph showing the effect of different drying temperatures on the content of gastrodin in Gastrodia elata Blume in the present invention. Among them, different letters a, b, c, d, and e represent significant differences determined by Duncan's test (p < 0.05, where p represents the probability value).

[0045] Figure 4 This is the graph showing the effect of different drying times on the content of gastrodin in Gastrodia elata Blume in the present invention. Among them, different letters a, b, c, d, and ab represent significant differences determined by Duncan's test (p < 0.05, where p represents the probability value).

[0046] Figure 5 This is the graph showing the effect of traditional processing and light-assisted hot air drying technology on the content of gastrodin in Gastrodia elata Blume in the present invention. Among them, different letters a, b, c, d, and e represent significant differences determined by Duncan's test (p < 0.05, where p represents the probability value). Detailed implementation manners

[0047] The present invention will be further described below in conjunction with embodiments. The following embodiments are narrative and not restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0048] All kinds of experimental operations involved in the specific embodiments are conventional techniques in the art. For parts not specifically noted in this article, those of ordinary skill in the art can refer to various commonly used reference books, scientific and technological literatures, or relevant specifications, manuals, etc. before the filing date of this invention application for implementation.

[0049] A Gastrodia elata Blume processing method based on light-assisted heat for directional enhancement of gastrodin content, the method comprising selection of Gastrodia elata Blume raw materials, cleaning, screening, slicing, secondary screening, and ultraviolet light-assisted hot air drying.

[0050] Preferably, it includes the following steps:

[0051] (1) Slicing: Cut Gastrodia elata Blume into round slices with a thickness of 3 - 4.5 mm.

[0052] (2) Light-assisted hot air drying: Continuously assist hot air drying with ultraviolet light of 750 - 952 THz and 315 - 400 nm to obtain the finished product.

[0053] The hot air drying conditions are: drying at 90 - 160 °C for 1 - 5 h.

[0054] Preferably, the specific steps are as follows:

[0055] 1) Fruit selection: Select Gastrodia elata Blume fruits with a weight of 120 - 140 g per fruit.

[0056] 2) Cleaning: Clean the soil on the surface of Gastrodia elata Blume with running water.

[0057] 3) Screening: After cleaning, screen out and remove the Gastrodia elata fruits with mildew spots or rot found after cleaning.

[0058] 4) Slicing: Transversely cut the Gastrodia elata into slices with a thickness of 3 - 4.5 mm.

[0059] 5) Secondary screening: Conduct secondary screening on the slices, and select the thin Gastrodia elata slices without pests and without hollow hearts.

[0060] 6) Light-assisted hot air drying: Take 15 - 20 g of the thin Gastrodia elata slices and place them on a tray, then put them into a hot air drying oven. Under the condition of uniform and continuous stimulation of ultraviolet light at 750 - 952 THz and 315 - 400 nm, adjust the hot air drying temperature to 90 - 160 °C and dry for 1 - 5 h. Do not control the humidity of the drying environment to obtain the finished product.

[0061] 7) Dehumidify and package, sterilize and store.

[0062] Preferably, the Gastrodia elata fruits are fresh, without rot, pests, mildew spots, with uniform shape and appropriate size.

[0063] Preferably, use a slicing machine to transversely cut the Gastrodia elata into slices with a thickness of 3 - 4.5 mm.

[0064] Preferably, the ultraviolet light is ultraviolet light at 769 THz and 390 nm.

[0065] Preferably, the hot air drying temperature is 150 °C and dry for 3 h.

[0066] Application of the Gastrodia elata processing method as described above in increasing the content of gastrodin in Gastrodia elata.

[0067] Specifically, the related preparation and detection are as follows:

[0068] Example 1

[0069] See Figure 1 , select the Gastrodia elata fruits from Xiaocaoba, Zhaotong, Yunnan, China, which are fresh, without rot, pests, mildew spots, with uniform size and moderate maturity, and weigh 120 - 140 g. Wash the surface soil with running water, screen again after cleaning, remove the Gastrodia elata fruits with mildew spots or rot found after cleaning, and then cut the selected Gastrodia elata into round slices with a thickness of 3.9 mm, and conduct the following treatment:

[0070] Sun drying: The selected thin Gastrodia elata slices (50 g) are first steamed in a steamer at 100 °C for 20 min, and then placed in a glass petri dish and naturally dried in the sun for 4 days, turning them over every other day, detecting the change in water content, and collecting the materials when the water content reaches about 10% to obtain sun-dried Gastrodia elata.

[0071] Lyophilization: The thin slices of Gastrodia elata (50 g) after secondary selection were stored in a -80 °C refrigerator for 2 - 4 h, then placed in a vacuum freeze dryer. The system was evacuated to an absolute pressure of 60 - 70 Pa, pre-cooled to -60 °C, and freeze-dried for 18 h. When the moisture content of the Gastrodia elata slices was adjusted to about 10%, the material was discharged to obtain freeze-dried Gastrodia elata.

[0072] Hot air drying: The thin slices of Gastrodia elata (20 g) after secondary selection were placed on a tray and put into a hot air drying oven. The temperature was adjusted to 90 - 160 °C for drying for 4 h, and the slices were turned over every 1 h.

[0073] The dried Gastrodia elata was ground into powder using a grinder, and an appropriate amount of the powder was taken to measure and record the moisture content. 0.5 g of the powder was placed in a 50 mL centrifuge tube, 25 mL of a 50% methanol solution by volume was added, and it was placed in an ultrasonic instrument at 25 °C and a frequency of 40 kHz for ultrasonic treatment for 30 min. Then it was centrifuged at 8000 r / min and 4 °C for 20 min. The supernatant was taken and filtered through a 0.22 μm organic filter membrane into a brown injection vial and placed in a high performance liquid chromatograph for quantitative analysis.

[0074] The chromatographic grade gastrodin standard was prepared into standard solutions with concentrations of 0.5, 0.25, 0.08, 0.04, 0.02, 0.01 mg / mL, and the chromatographic peak areas were measured. Using the standard concentration (mg / mL) as the abscissa and the peak area as the ordinate, a standard curve was plotted and linear regression calculation was performed: Gastrodin standard curve: Y = 2×10 7 x + 81316, R 2 = 0.9998 ( Figure 2 )

[0075] The content of gastrodin in Gastrodia elata was detected using a high performance liquid chromatograph at a detection wavelength of 220 nm. Chromatographic column: kromasil C18 (250 mm × 4.6 mm, 5 μm); column temperature: 30 °C; injection volume: 20 μL; Phase A: aqueous solution containing 0.1% formic acid, Phase B: methanol containing 0.1% formic acid; flow rate: 1 mL / min. The solvent elution gradient of Phase B was: 0 - 2 min: 5%, 2 - 4 min: 5 - 15%, 4 - 12 min: 15 - 25%, 25 - 35 min: 25 - 35%, 25 - 28 min: 35 - 100%, 28 - 30 min: 100%, 30 - 30.5 min: 100 - 5%, 30.5 - 32 min: 5%.

[0076] When the drying time was 4 h, the change in the gastrodin content of Gastrodia elata after different drying temperatures was as Figure 3As shown, the content of gastrodin in sun-dried gastrodia elata is 3.51 mg / g, and the content of gastrodin in freeze-dried gastrodia elata is 2.76 mg / g. Moreover, the content of gastrodin shows a trend of first increasing and then decreasing with the increase of drying temperature. When the temperature increases to 150 °C, the content of gastrodin reaches the highest at 8.56 mg / g, which is 2.44 times that of sun-dried gastrodia elata and 3.10 times that of freeze-dried gastrodia elata. As the temperature continues to increase to 160 °C, the content of gastrodin in gastrodia elata decreases to 5.93 mg / g. It can be seen that appropriately increasing the drying temperature can convert some gastrodigenin in gastrodia elata into gastrodin, thereby increasing the content of gastrodin. And the content of gastrodin at 150 °C for 4 h has a significant difference compared with that after other different temperature treatments. Therefore, Example 2 will explore the influence of the change of gastrodin content in gastrodia elata after different drying times at 150 °C.

[0077] Example 2

[0078] See Figure 1 , select fresh, non-rotten, pest-free, mold-free, and evenly sized moderately mature gastrodia elata fruits from Xiaocaoba, Zhaotong, Yunnan, China, with a weight of 120 - 140 g. Rinse off the soil on the surface with running water, and after cleaning, screen again to remove the gastrodia elata fruits with mold or rot found after cleaning. Then cut the selected gastrodia elata into round slices with a thickness of 3.9 mm and perform the following treatments:

[0079] Sun-drying: The secondarily selected gastrodia elata slices (50 g) are first steamed in a steamer at 100 °C for 20 min, and then placed in a glass petri dish to be naturally sun-dried for 4 days, turning them over every other day. Detect the change in water content, and collect the materials when the water content reaches about 10% to obtain sun-dried gastrodia elata.

[0080] Freeze-drying: The secondarily selected gastrodia elata slices (50 g) are placed in a -80 °C refrigerator for 2 - 4 h, and then put into a vacuum freeze-dryer. The system is evacuated to an absolute pressure of 60 - 70 Pa, pre-cooled to -60 °C, and freeze-dried for 18 h. When the water content of the gastrodia elata slices is regulated to about 10%, the materials are discharged to obtain freeze-dried gastrodia elata.

[0081] Hot air drying: The secondarily selected gastrodia elata slices (20 g) are loaded onto a plate and placed in a hot air drying oven. The temperature is regulated to dry at 150 °C for 1 - 5 h, and the slices are turned over every 1 h.

[0082] The method for sample extraction and determination of gastrodin content is the same as that in Example 1.

[0083] When the drying temperature is 150 °C, the change in gastrodin content in gastrodia elata after different drying times is as Figure 4As shown in the figure, the content of gastrodin in sun-dried gastrodia elata is 3.51 mg / g, and the content of gastrodin in freeze-dried gastrodia elata is 2.76 mg / g. Moreover, the content of gastrodin shows a trend of first increasing and then decreasing with the extension of the drying time. When the drying time is extended to 3 h, the highest content of gastrodin is 10.05 mg / g, which is 2.86 times that of sun-dried gastrodia elata and 3.64 times that of freeze-dried gastrodia elata. After that, as the drying time is further extended to 5 h, the content of gastrodin gradually decreases to 7.75 mg / g. It can be seen that an appropriate drying time is also a key factor in increasing the content of gastrodin in gastrodia elata, and the content of gastrodin is the highest at 150°C and 3 h. Compared with the content of gastrodin after being treated with different drying temperatures and times, the value shows a significant difference. Therefore, regulating suitable drying parameters is crucial for increasing the content of gastrodin. In Example 3, on the basis of these optimal drying parameters, ultraviolet light irradiation will be used as an auxiliary to further explore its influence on the content of gastrodin.

[0084] Example 3

[0085] See Figure 1 , select fresh, non-rotten, pest-free, mold-free, and evenly sized moderately mature gastrodia elata fruits from Xiaocaoba, Zhaotong, Yunnan, China, with a weight of 120 - 140 g. Rinse the surface soil with running water, and after cleaning, screen again to remove the gastrodia elata fruits with mold or rot found after cleaning. Then cut the selected gastrodia elata into round slices with a thickness of 3.9 mm and perform the following treatments:

[0086] Sun-drying: The secondarily selected gastrodia elata slices (50 g) are first steamed in a steamer at 100°C for 20 min, and then placed in a glass petri dish and naturally dried in the sun for 4 days, turning them over every other day. Detect the change in water content, and collect the materials when the water content reaches about 10% to obtain sun-dried gastrodia elata.

[0087] Freeze-drying: The secondarily selected gastrodia elata slices (50 g) are placed in a -80°C refrigerator and stored for 2 - 4 h, then put into a vacuum freeze-dryer. Evacuate to an absolute system pressure of 60 - 70 Pa, pre-cool to -60°C, and freeze-dry for 18 h. Control the water content of the gastrodia elata slices to about 10% and then discharge to obtain freeze-dried gastrodia elata.

[0088] Steaming: The secondarily selected gastrodia elata slices (50 g) are placed in a steamer and steamed at 100°C for 20 min to obtain the finished product.

[0089] Steaming combined with hot air drying: The secondarily selected gastrodia elata slices (50 g) are placed in a steamer and steamed at 100°C for 20 min, then loaded onto a plate and placed in a hot air drying oven. Control the temperature at 150°C and dry for 3 h to obtain the finished product, turning them over every 1 h.

[0090] Ultraviolet light-assisted hot air drying: The sliced gastrodia elata (20 g) after secondary selection was loaded onto a tray and placed in a hot air drying oven. Under the condition of uniform and continuous stimulation by ultraviolet light (769 THz, 390 nm), the temperature was controlled at 150 °C for drying for 3 h, and the slices were turned over every 1 h.

[0091] The sample extraction and the determination method of gastrodin content were the same as those in Example 1.

[0092] As Figure 5 shown, the gastrodin contents in sun-dried, freeze-dried, and steamed gastrodia elata were 3.51 mg / g, 2.76 mg / g, and 0.64 mg / g respectively. At the same time, the gastrodin content (7.52 mg / g) of gastrodia elata after steaming combined with hot air drying at 150 °C for 3 h was also measured as a control. The gastrodin content in gastrodia elata after ultraviolet light combined with hot air drying at 150 °C for 3 h was 20.28 mg / g, which was 5.78 times, 7.35 times, and 2.70 times the gastrodin contents in sun-dried, freeze-dried, and steamed combined with hot air drying at 150 °C for 3 h respectively. In addition, based on the improvement of gastrodin content by using hot air drying alone at 150 °C for 3 h, the addition of ultraviolet light assistance could further increase the gastrodin content by 102%, further enhancing the gastrodin content. After processing gastrodia elata by the method of the present invention, balisonglycoside compounds and p-hydroxybenzyl alcohol in gastrodia elata can be converted into gastrodin, doubling the gastrodin content. Only the gastrodin content is significantly higher than the standard that the total amount of gastrodin and p-hydroxybenzyl alcohol in gastrodia elata in the Chinese Pharmacopoeia shall not be less than 2.5 mg / g. Using the ultraviolet light-assisted hot air drying technology can not only double the gastrodin content in gastrodia elata while retaining it, but also shorten the drying time and improve the drying efficiency. Therefore, it is very necessary to use this technology for convenient and accurate processing of gastrodin in gastrodia elata.

[0093] It can also be seen that there is a synergistic effect between the two steps of ultraviolet light (769 THz, 390 nm) and hot air drying at 150 °C for 3 h in the method of the present invention, which can synergistically increase the gastrodin content in the prepared gastrodia elata.

[0094] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that: various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments.

Claims

1. A processing method for Gastrodia elata based on photo-assisted heat-directed enhancement of gastrodin content, characterized in that: The method includes selecting Gastrodia elata raw materials, cleaning, screening, slicing, secondary screening, and ultraviolet light-assisted hot air drying: It includes the following steps: (1) Slicing: Cut Gastrodia elata into circular thin slices with a thickness of 3 - 4.5 mm; (2) Light-assisted hot air drying: Use ultraviolet light with a frequency of 750 - 952 THz and a wavelength of 315 - 400 nm to continuously assist hot air drying to obtain the finished product; The conditions for hot air drying are: drying at 90 - 160 °C for 1 - 5 h.

2. The gastrodia elata processing method according to claim 1, wherein: The specific steps are as follows: 1) Fruit selection: Select Gastrodia elata fruits with a weight of 120 - 140 g per fruit; 2) Cleaning: Wash the soil on the surface of Gastrodia elata with running water; 3) Screening: After cleaning, screen to remove Gastrodia elata fruits with mildew spots or rot found after cleaning; 4) Slicing: Horizontally cut Gastrodia elata into slices with a thickness of 3 - 4.5 mm; 5) Secondary screening: Conduct secondary screening on the slices to select Gastrodia elata thin slices without pests and without hollow hearts; 6) Light-assisted hot air drying: Take 15 - 20 g of Gastrodia elata thin slices and place them on a plate, put them into a hot air drying oven, and under the condition of uniform and continuous stimulation of ultraviolet light with a frequency of 750 - 952 THz and a wavelength of 315 - 400 nm, adjust the hot air drying temperature to dry at 90 - 160 °C for 1 - 5 h, and do not control the humidity of the drying environment to obtain the finished product; 7) Dehumidify and package, sterilize and store.

3. The gastrodia elata processing method according to claim 1, wherein: The Gastrodia elata is a fresh, non-rotten, pest-free, mildew-free, evenly shaped and moderately sized Gastrodia elata fruit.

4. The gastrodia elata processing method according to claim 1, wherein: Use a slicing machine to horizontally cut Gastrodia elata into slices with a thickness of 3 - 4.5 mm.

5. The gastrodia elata processing method according to claim 1, characterized in that: The ultraviolet light is ultraviolet light with a frequency of 769 THz and a wavelength of 390 nm.

6. The Gastrodia elata processing method according to any one of claims 1 to 5, characterized in that: The hot air drying temperature is drying at 150 °C for 3 h.

7. Use of the Gastrodia elata processing method according to any one of claims 1 to 6 in increasing the content of gastrodin in Gastrodia elata.

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