Process for extracting rhododendron dauricum essential oil by synergistically promoting hydro-distillation through glucose oxidase

Abstract

The invention discloses a process for extracting folium rhododendri daurici essential oil by synergistically promoting hydro-distillation through glucose oxidase, and belongs to the technical field of folium rhododendri daurici essential oil extraction.The process comprises the following steps that S1, folium rhododendri daurici leaves are checked, impurities, worm eggs and moldy leaves are removed, and the folium rhododendri daurici leaves are ground and sieved; s2, adding a proper amount of sterile ddH2O, uniformly mixing, adding an enzyme preparation, and performing water bath; s3, after the water bath is finished, distilling and extracting the rhododendron dauricum essential oil. According to the process for extracting the rhododendron dauricum essential oil by synergistically promoting the hydro-distillation through the glucose oxidase, through mutual cooperation of various enzymes, the dissolution rate and the extraction rate of the rhododendron dauricum essential oil can be greatly increased, the content of oxygen-containing compounds in effective components-volatile components in the rhododendron dauricum essential oil is increased, and then the utilization rate of the rhododendron dauricum is increased; the method is green and efficient, consumes short time, does not use an organic solvent, and does not affect subsequent research and application; the method has low requirements on equipment, is simple and easy to operate and can be used for industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of extracting essential oil from Rhododendron dauricum L., and in particular to a process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation promoted by glucose oxidase Background Art

[0002] Rhododendron dauricum L. is a traditional Chinese medicine. According to the "Dictionary of Traditional Chinese Medicine", its aliases are Rhododendron dauricum L. var. mollifolium Nakai, Rhododendron mucronulatum Turcz., Rhododendron parvifolium Adams, and Rhododendron dauricum L. It is the dried leaves of Rhododendron dauricum L. of the genus Rhododendron in the family Ericaceae. It is harvested in summer and autumn and dried in the shade or in the sun. It is mostly rolled into a tube shape, and some are wrinkled and broken. After the complete leaves are flattened, they are oval or oblong-ovate, 2-7.5 cm long and 1-3 cm wide, with a blunt apex, a nearly round or broadly cuneate base, entire margins, dark green to brownish green on the upper surface, scattered with light yellow glandular scales, and grayish green on the lower surface with many glandular scales.

[0003] Rhododendron dauricum L. has a fragrant smell, is cold in nature and bitter in taste. Various preparations and volatile oils extracted from Rhododendron dauricum L. with ethanol or water have the effects of relieving cough and reducing phlegm when taken orally or by intraperitoneal injection. It is commonly used for acute and chronic bronchitis, relieving cough, reducing phlegm and relieving asthma. Because of its fragrant smell, the essential oil of Rhododendron dauricum L. is often used in the production of essence and blending spices, and is also used in tobacco flavoring.

[0004] At present, the main methods for extracting essential oil from Rhododendron dauricum L. are steam distillation method, compound solvent extraction method, supercritical CO2 extraction method, microwave distillation method, etc. There are problems such as low extraction rate of essential oil, few types of extracted components, insufficient utilization of Rhododendron dauricum L., waste of resources, time-consuming, high requirements for equipment, and the influence of organic solvent residues on subsequent research and utilization. Summary of the Invention

[0005] The purpose of the present invention is to provide a process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation promoted by glucose oxidase to solve the problems of low extraction rate of essential oil from Rhododendron dauricum L., insufficient utilization, time-consuming, high requirements for extraction equipment, and organic solvent residues in the current methods.

[0006] To achieve the above purpose, the present invention provides a process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation promoted by glucose oxidase, and the steps are as follows:

[0007] S1. Check the leaves of Rhododendron dauricum L., remove impurities, insect eggs and mildewed leaves, powder and sieve.

[0008] S2. Add an appropriate amount of sterile ddH2O, mix evenly and then add enzyme preparation, and perform water bath.

[0009] S3. After the water bath is completed, distill and extract the essential oil of Rhododendron dauricum L.

[0010] Preferably, the Rhododendron dauricum leaves in step S1 are dry leaves obtained by low-temperature drying or air-drying of fresh leaves; the sieving refers to sieving through a 40-mesh sieve.

[0011] Preferably, in step S2, the mass ratio of sterile ddH2O to Rhododendron dauricum powder is 1:15, and the pH is adjusted to 4-6 after adding sterile ddH2O.

[0012] Preferably, the enzyme preparation in step S2 is a mixture of one of cellulase, hemicellulase, pectinase, α-amylase and glucose oxidase; the method of adding the enzyme preparation is to first add one of cellulase, hemicellulase, pectinase, α-amylase, and after mixing evenly, then add glucose oxidase.

[0013] Preferably, the enzyme activity to mass ratio of cellulase / hemicellulase / pectinase / α-amylase to dry Rhododendron dauricum powder is 600U:1g.

[0014] Preferably, the enzyme preparation is a mixture of cellulase and glucose oxidase, the activity unit ratio of cellulase to glucose oxidase is 6:1, and the enzyme activity unit to mass ratio of the added amount of glucose oxidase to dry Rhododendron dauricum powder is 200U:1g.

[0015] Preferably, the water bath condition in step S2 is 50-70°C for 1h.

[0016] Preferably, the distillation extraction condition in step S3 is heating with a 100W water bath and a distillation time of 1-2h.

[0017] An application of the extraction process of Rhododendron dauricum essential oil by glucose oxidase synergistically promoting hydrogel distillation as described above in the extraction of Rhododendron dauricum essential oil.

[0018] In the present invention, at the optimal pH and optimal reaction temperature, cellulase / hemicellulase / pectinase / α-amylase is used to fully destroy the cell structure of Rhododendron dauricum, and at the same time, glucose oxidase is used to rapidly hydrolyze the glucose released from the cells, avoiding the inhibitory effect of the increased glucose in the environment on the activity of cellulase / hemicellulase / pectinase / α-amylase, so as to ensure the continuous and efficient progress of the enzymatic hydrolysis reaction, thereby greatly increasing the dissolution rate of Rhododendron dauricum essential oil, improving the yield of Rhododendron dauricum essential oil, and making full use of Rhododendron dauricum.

[0019] Therefore, the extraction process of Rhododendron dauricum essential oil by glucose oxidase synergistically promoting hydrogel distillation provided by the present invention has the following specific technical effects: [[ID=...]] [[ID=...]]

[0020] (1) The extraction process provided by the present invention can greatly improve the dissolution rate and extraction rate of Rhododendron dauricum essential oil through the mutual cooperation of multiple enzymes, increase the content of oxygenated compounds in the volatile components, which are the effective components in Rhododendron dauricum essential oil, and thus improve the utilization rate of Rhododendron dauricum.

[0021] (2) The extraction process provided by the present invention is green and efficient, time-consuming short, does not use organic solvents, and does not affect subsequent research and applications.

[0022] (3) The extraction process provided by the present invention has low requirements for equipment, is simple and easy to operate, and can be industrially produced.

[0023] The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is the single-factor experimental result of the extraction rate of Rhododendron dauricum essential oil with different enzyme types in the embodiment of the present invention;

[0026] Figure 2 It is the single-factor experimental result of the extraction rate of Rhododendron dauricum essential oil with different enzyme addition amounts in the embodiment of the present invention;

[0027] Figure 3 It is the single-factor experimental result of the extraction rate of Rhododendron dauricum essential oil with different water bath temperatures in the embodiment of the present invention;

[0028] Figure 4 It is the single-factor experimental result of the extraction rate of Rhododendron dauricum essential oil with the pH of the reaction solution in the embodiment of the present invention;

[0029] Figure 5 It is the result of the extraction rate of Rhododendron dauricum essential oil with different addition amounts of glucose oxidase in the embodiment of the present invention;

[0030] Figure 6 It is the total ion current chromatogram of the Rhododendron dauricum essential oil extracted in Example 4 of the present invention;

[0031] Figure 7 It is the total ion current chromatogram of the Rhododendron dauricum essential oil extracted in the comparative example. Detailed Embodiments

[0032] The technical solution of the present invention will be further described below through the accompanying drawings and embodiments.

[0033] In order to make the purpose, technical solutions and advantages of the present application more clear, thorough and complete, the technical solutions of the present invention will be clearly and completely described below through the accompanying drawings and embodiments. The following detailed descriptions are all descriptions of embodiments, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms adopted by the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present application belongs.

[0034] The instruments, equipment, reagents and materials used in the examples were all obtained through commercial channels. Glucose oxidase was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., with an enzyme activity of 10,000 U / g. Hemicellulase was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., with an enzyme activity of 20,000 U / g. Pectinase was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., with an enzyme activity of 50,000 U / g. α-Amylase was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with an enzyme activity of 1,500 U / g. Cellulase was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with an enzyme activity of 10,000 U / g.

[0035] Example 1

[0036] A pre-experiment on the extraction of Rhododendron dauricum essential oil was carried out as follows:

[0037] Remove the impurities, insect eggs and mildewed leaves from the Rhododendron dauricum leaves. Cut the leaves into small pieces with a side length not greater than 0.5 cm with scissors and add them to the powder mill bin. Sample with the powder mill for 90 s, and then pass the obtained dry powder through a 40-mesh sieve. Divide the sieved Rhododendron dauricum powder into 2 parts, 50 g each, and label them as the cellulase group and the glucose oxidase-cellulase group respectively.

[0038] Add 750 mL of sterilized ddH2O to the cellulase group. After stirring and mixing evenly, adjust the pH to 5 with 1 M NaOH and 1 M HCl, and add 3 g of cellulase; add 750 mL of sterilized ddH2O to the glucose oxidase-cellulase group. After stirring and mixing evenly, adjust the pH to 5 with 1 M NaOH and 1 M HCl, and add 3 g of cellulase and 1 g of glucose oxidase.

[0039] After stirring and mixing evenly, put all the liquid into a 3000 mL round-bottom flask and enzymolyze it at 50 °C for 1 h in a water bath. After the enzymolysis is completed, place the flask and its solution in a water bath pot, install a light oil extractor and a condenser above it, and heat it at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the Rhododendron dauricum essential oil.

[0040] The following formula was used: extraction rate of Rhododendron dauricum essential oil = mass of Rhododendron dauricum essential oil / mass of dry Rhododendron dauricum powder to calculate the extraction rate of Rhododendron dauricum essential oil. The extraction rate of the cellulase group was 0.1493%, and that of the glucose oxidase - cellulase group was 0.1848%. The extraction rate of Rhododendron dauricum essential oil in the glucose oxidase - cellulase group was significantly improved.

[0041] Example 2

[0042] A single - factor experiment on the extraction of Rhododendron dauricum essential oil was carried out as follows:

[0043] (1) Type of enzyme

[0044] The impurities, eggs and mildewed leaves in Rhododendron dauricum leaves were removed. The leaves were cut into small pieces with side lengths not greater than 0.5 cm using scissors and added to the powdering machine bin. The powdering machine was used for 90 s, and then the obtained dry powder was passed through a 40 - mesh sieve. The sieved Rhododendron dauricum powder was divided into 4 portions, each weighing 50 g, and were respectively denoted as the hemicellulase group, pectinase group, α - amylase group, and cellulase group.

[0045] The hemicellulose group was added with 750 mL of sterilized ddH2O. After stirring and mixing evenly, the pH was adjusted to 5 with 1M NaOH and 1M HCl, and 3 g of hemicellulase was added; the pectinase group was added with 750 mL of sterilized ddH2O. After stirring and mixing evenly, the pH was adjusted to 5 with 1M NaOH and 1M HCl, and 3 g of pectinase was added; the α - amylase group was added with 750 mL of sterilized ddH2O. After stirring and mixing evenly, the pH was adjusted to 5 with 1M NaOH and 1M HCl, and 3 g of α - amylase was added; the cellulase group was added with 750 mL of sterilized ddH2O. After stirring and mixing evenly, the pH was adjusted to 5 with 1M NaOH and 1M HCl, and 3 g of cellulase was added.

[0046] After stirring and mixing evenly, all the liquid was put into a 3000 - mL round - bottom flask and enzymolyzed at 50 °C in a water bath for 1 h. After the enzymolysis ended, the flask and its solution were placed in a water bath, and a light oil extractor and a condenser were installed above. It was heated at a power of 100 W for 1.5 h. The oily substance above the light oil extractor was collected, which was the Rhododendron dauricum essential oil. The following formula was used: extraction rate of Rhododendron dauricum essential oil = mass of Rhododendron dauricum essential oil / mass of dry Rhododendron dauricum powder to calculate the extraction rate of Rhododendron dauricum essential oil.

[0047] The extraction rates of Rhododendron dauricum essential oil obtained by the hemicellulase group, pectinase group, α - amylase group, and cellulase group are shown in Figure 1 .

[0048] It can be seen from Figure 1 that cellulase is the optimal enzyme choice, and the extraction rate of Rhododendron dauricum essential oil is 0.1498%.

[0049] (2) Dosage of enzyme

[0050] Select cellulase for the experiment. Remove impurities, eggs, and mildewed leaves from the leaves of Rhododendron dauricum L. Use scissors to cut the leaves into small pieces with side lengths not greater than 0.5 cm, and add them to the powder mill bin. Sample with the powder mill for 90 s, then pass the obtained dry powder through a 40-mesh sieve, and divide the sieved Rhododendron dauricum L. powder into 5 portions, each portion being 50 g.

[0051] Add 750 mL of sterilized ddH2O respectively, adjust the pH to 5 with 1 M NaOH and 1 M HCl, and add 1.5 g, 3 g, 4.5 g, 6 g, and 7.5 g of cellulase respectively. Calculated based on the overall solution, the enzyme concentrations are 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% respectively.

[0052] After stirring and mixing evenly, put all the liquid into a 3000 mL round-bottom flask, and carry out enzymatic hydrolysis at 50 °C in a water bath for 1 h. After the enzymatic hydrolysis is completed, place the flask and its solution in a water bath, install a light oil extractor and a condenser above, and heat at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the essential oil of Rhododendron dauricum L. Calculate the extraction rate of the essential oil of Rhododendron dauricum L. using the following formula: extraction rate of the essential oil of Rhododendron dauricum L. = mass of the essential oil of Rhododendron dauricum L. / mass of the dry powder of Rhododendron dauricum L.

[0053] Calculate the extraction rates of the essential oil of Rhododendron dauricum L. obtained with different enzyme addition amounts as shown in Figure 2 .

[0054] It can be seen from Figure 2 that when the cellulase addition amount reaches 0.6%, the optimal enzyme concentration is reached, and the extraction rate of the essential oil of Rhododendron dauricum L. is 0.1657%.

[0055] (3) Water bath temperature

[0056] Select cellulase for the experiment. Remove impurities, eggs, and mildewed leaves from the leaves of Rhododendron dauricum L. Use scissors to cut the leaves into small pieces with side lengths not greater than 0.5 cm, and add them to the powder mill bin. Sample with the powder mill for 90 s, then pass the obtained dry powder through a 40-mesh sieve, and divide the sieved Rhododendron dauricum L. powder into 5 portions, each portion being 50 g.

[0057] Add 750 mL of sterilized ddH2O respectively, adjust the pH to 5 with 1 M NaOH and 1 M HCl, and add 4.5 g of cellulase respectively. After stirring and mixing evenly, put all the liquid into a 3000 mL round-bottom flask, and carry out enzymatic hydrolysis at 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C in a water bath for 1 h respectively. After the enzymatic hydrolysis is completed, place the flask and its solution in a water bath, install a light oil extractor and a condenser above, and heat at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the essential oil of Rhododendron dauricum L.

[0058] Use the following formula: extraction rate of Rhododendron dauricum essential oil = mass of Rhododendron dauricum essential oil / mass of Rhododendron dauricum dry powder to calculate the extraction rate of Rhododendron dauricum essential oil. The extraction rates of Rhododendron dauricum essential oil obtained in different water bath temperature groups are shown in Figure 3 。

[0059] From Figure 3 it can be seen that the optimal water bath temperature is 70 °C, and the extraction rate of Rhododendron dauricum essential oil is 0.1749%.

[0060] (4) pH

[0061] Select cellulase for the experiment. Remove impurities, eggs and mildewed leaves from Rhododendron dauricum leaves. Use scissors to cut the leaves into small pieces with side lengths not greater than 0.5 cm, and add them to the powder mill bin. Grind the sample for 90 s with a powder mill, then pass the obtained dry powder through a 40-mesh sieve, and then divide the Rhododendron dauricum powder into 5 portions, each portion being 50 g.

[0062] Add 750 mL of sterilized ddH2O respectively, adjust the pH to 3, 4, 5, 6, 7 with 1 M NaOH and 1 M HCl respectively, and then add 4.5 g of cellulase respectively. After stirring and mixing evenly, put all the liquid into a 3000 mL round-bottom flask, and carry out enzymatic hydrolysis at 70 °C water bath for 1 h. After the enzymatic hydrolysis is completed, place the flask and its solution in a water bath pot, install a light oil extractor and a condenser above, and heat at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the Rhododendron dauricum essential oil.

[0063] Use the following formula: extraction rate of Rhododendron dauricum essential oil = mass of Rhododendron dauricum essential oil / mass of Rhododendron dauricum dry powder to calculate the extraction rate of Rhododendron dauricum essential oil.

[0064] The extraction rates of Rhododendron dauricum essential oil obtained from reaction solutions with different pH values are shown in Figure 4 。

[0065] From Figure 4 it can be seen that the optimal pH is 5, and the extraction rate of Rhododendron dauricum essential oil is 0.179%.

[0066] Example 3

[0067] Determine the optimal parameter combination for the extraction of Rhododendron dauricum essential oil as follows:

[0068] According to the single-factor experimental results of Example 2, a three-level and three-variable Box-Behnken experimental design obtained by Design Expert 8.0 was used to calculate the effects of each single factor and its interaction factors on the yield of Rhododendron dauricum essential oil, optimize the extraction process of Rhododendron dauricum essential oil, and predict the optimal yield. The three variables of the response surface experiment were determined according to the single-factor experiment, namely enzyme concentration, water bath temperature, and pH. Taking the yield of Rhododendron dauricum essential oil as the response value, a total of 17 groups of experiments were included. Experiments were carried out respectively according to the experimental conditions given by the response surface software, and the average value of the yield of Rhododendron dauricum essential oil under each experimental condition was recorded (the results are shown in Table 1). After corresponding the yield of Rhododendron dauricum essential oil with the corresponding conditions, it was input into the software for variance analysis to analyze the experimental data and test the significance of the statistical model.

[0069] Table 1

[0070]

[0071]

[0072] The optimal extraction conditions of Rhododendron dauricum essential oil predicted by the response surface software were as follows: pH was 4, water bath temperature was 66 °C, and cellulase concentration was 0.8%. Under the above conditions, the model predicted that the optimal yield of Rhododendron dauricum essential oil could reach 0.175%. Three verification experiments were carried out with the obtained conditions, and finally the yield of Rhododendron dauricum essential oil was 0.1752 ± 0.0042%, indicating that the experimental value and the predicted value of the yield of Rhododendron dauricum essential oil could fit well under the extraction conditions predicted by the model.

[0073] Example 4

[0074] Extract Rhododendron dauricum essential oil with the optimal parameter combination determined in Example 3, and the method is as follows:

[0075] Select cellulase for the experiment, remove impurities, insect eggs, and mildewed leaves in Rhododendron dauricum leaves, cut the leaves into small pieces with a side length not greater than 0.5 cm with scissors, and add them to the sample grinder bin. Grind the sample for 90 s with a sample grinder, then pass the obtained dry powder through a 40-mesh sieve, and divide the sieved Rhododendron dauricum powder into 4 portions, each portion being 50 g.

[0076] Add 750 mL of sterilized ddH2O respectively, adjust the pH to 4 with 1 M NaOH and 1 M HCl, and add 6.0 g of cellulase respectively. Then add 0.5 g, 1.0 g, 1.5 g, and 2.0 g of glucose glucoamylase to them.

[0077] After stirring and mixing evenly, put all the liquid into a 3000 mL round-bottom flask and enzymatically hydrolyze it at 66 °C in a water bath for 1 h. After the enzymatic hydrolysis is completed, place the flask and its solution in a water bath, install a light oil extractor and a condenser above it, and heat it at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the essential oil of Rhododendron dauricum L..

[0078] Use the following formula: extraction rate of essential oil of Rhododendron dauricum L. = mass of essential oil of Rhododendron dauricum L. / mass of dry powder of Rhododendron dauricum L. to calculate the extraction rate of essential oil of Rhododendron dauricum L.. The extraction rates of essential oil of Rhododendron dauricum L. obtained with different addition amounts of glucose oxidase are shown in Figure 5 .

[0079] It can be seen from Figure 5 that when the addition amount of glucose oxidase is 1.0 g, the extraction rate begins to reach the maximum value, and the calculated extraction rate of essential oil of Rhododendron dauricum L. is 0.2139%.

[0080] Comparative example

[0081] Extract the essential oil of Rhododendron dauricum L. by the currently commonly used method. The method is as follows:

[0082] Currently, the commonly used method for extracting the essential oil of Rhododendron dauricum L. is the steam distillation method. The specific method is as follows:

[0083] Remove the impurities, insect eggs and mildewed leaves in the Rhododendron dauricum L. leaves, cut the leaves into small pieces with side lengths not greater than 0.5 cm with scissors, and add them to the powder mill bin. Grind for 90 s with a powder mill, then pass the obtained dry powder through a 40-mesh sieve, weigh 50 g of the sieved Rhododendron dauricum L. powder, and add it to a 3000 mL round-bottom flask.

[0084] Add 750 mL of sterilized ddH2O to the round-bottom flask. After stirring and mixing evenly, place the flask and its solution in a water bath, install a light oil extractor and a condenser above it, and heat it at a power of 100 W for 1.5 h. Collect the oily substance above the light oil extractor, which is the essential oil of Rhododendron dauricum L..

[0085] Use the following formula: extraction rate of essential oil of Rhododendron dauricum L. = mass of essential oil of Rhododendron dauricum L. / mass of dry powder of Rhododendron dauricum L. to calculate the extraction rate of essential oil of Rhododendron dauricum L., and the extraction rate of essential oil of Rhododendron dauricum L. is 0.1224%.

[0086] Effect example

[0087] Perform GC-MS detection on the essential oil of Rhododendron dauricum L. extracted in Example 4 and the comparative example:

[0088] The gas chromatography conditions are as follows: the carrier gas is high-purity helium, the flow rate is 1 μL / min, and the split ratio is 1:20; the inlet temperature is 250 °C. Temperature programming: the initial temperature is 50 °C, hold for 2 min, increase the temperature to 160 °C at a rate of 4 °C / min, hold for 2 min; increase the temperature to 270 °C at a rate of 4 °C / min, hold for 5 min.

[0089] Mass spectrometry conditions: Electron impact (EI) ion source, ionization voltage 70 eV; solvent delay time 3.5 min; ion source temperature 230 °C; scanning range 29 - 600 amu.

[0090] The total ion chromatogram of the Rhododendron dauricum essential oil extracted in Example 4 is shown in Figure 6 , and the total ion chromatogram of the Rhododendron dauricum essential oil extracted in the comparative example is shown in Figure 7 . From Figure 6 and Figure 7 , it can be seen that the proportion of oxygen-containing compounds in the volatile oil components, which are the active ingredients extracted from the Rhododendron dauricum essential oil prepared in Example 4, is higher than that in the Rhododendron dauricum essential oil extracted by the traditional method.

[0091] The chemical components and relative mass fractions of each component of the Rhododendron dauricum essential oil extracted in Example 4 analyzed by GC-MS are shown in Table 2, and the chemical components and relative mass fractions of each component of the Rhododendron dauricum essential oil extracted in the comparative example are shown in Table 3.

[0092] Table 2

[0093]

[0094]

[0095]

[0096] Table 3

[0097]

[0098]

[0099]

[0100] From the information in Table 2 and Table 3, it can be known that the Rhododendron dauricum essential oil (Example 4) extracted by using the Rhododendron dauricum essential oil extraction method provided by the present invention retains most of the volatile components of Rhododendron dauricum, and significantly improves the extraction rate of the Rhododendron dauricum essential oil.

[0101] Therefore, a glucose oxidase synergistic promotion hydrodistillation Rhododendron dauricum essential oil extraction process provided by the present invention can significantly improve the dissolution rate and extraction rate of the Rhododendron dauricum essential oil through the mutual cooperation of multiple enzymes, increase the content of oxygen-containing compounds in the volatile components, which are the active ingredients in the Rhododendron dauricum essential oil, and thus improve the utilization rate of Rhododendron dauricum; it is green and efficient, time-consuming short, does not use organic solvents, and does not affect subsequent research and applications; it has low requirements for equipment, is simple and easy to operate, and can be industrially produced.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements do not enable the modified technical solutions to depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation with the synergistic promotion of glucose oxidase, characterized in that, Here are the steps: S1. Check the red leaves on the mountain, remove impurities, insect eggs and moldy leaves, grind them into powder and sieve; S2. Add an appropriate amount of sterile ddH2O, mix well, add enzyme preparation, and place in water bath; S3. After the water bath is completed, distill and extract the Rhododendron australis essential oil.

2. The extraction process of Rhododendron dauricum essential oil by hydrodistillation synergistically promoted by glucose oxidase according to claim 1, wherein: The Manshanhongye in step S1 is fresh leaves that have been dried by low-temperature extraction or shade drying; the sieving refers to sieving through a 40-mesh sieve.

3. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation synergistically promoted by glucose oxidase according to claim 1, characterized in that: In step S2, the mass ratio of sterile ddH2O to Rhodiola rosea powder is 1:15, and the pH is adjusted to 4-6 after adding sterile ddH2O.

4. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation with the synergistic promotion of glucose oxidase according to claim 1, characterized in that: The enzyme preparation in step S2 is a mixture of one of cellulase, hemicellulase, pectinase, α-amylase and glucose oxidase; the method of adding the enzyme preparation is to first add one of cellulase, hemicellulase, pectinase, α-amylase, mix well, and then add glucose oxidase.

5. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation with the synergistic promotion of glucose oxidase according to claim 4, characterized in that: Cellulase / hemicellulase / pectinase / α-amylase: The enzyme activity to mass ratio of Rhizoma Cynanchum dry powder is 600U:1g.

6. The extraction process of Rhododendron dauricum essential oil by hydrodistillation promoted by glucose oxidase according to claim 4, characterized in that: The enzyme preparation is a mixture of cellulase and glucose oxidase, the activity unit ratio of cellulase: glucose oxidase is 6:1, and the added amount of glucose oxidase: the enzyme activity unit and mass ratio of Manshanhong dry powder is 200U:1g.

7. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation synergistically promoted by glucose oxidase according to claim 1, characterized in that: The water bath condition in step S2 is 50-70° C. for 1 hour.

8. A process for extracting essential oil from Rhododendron dauricum L. by hydrodistillation synergistically promoted by glucose oxidase according to claim 1, characterized in that: The distillation extraction conditions in step S3 are heating the water bath at 100W and the distillation time is 1-2 hours.

9. Use of the glucose oxidase-assisted hydrocondensation distillation Rhododendron chinense essential oil extraction process as described in any one of claims 1 to 8 in the extraction of Rhododendron chinense essential oil.

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