Efficient extraction method of fructus galangae flower essential oil

Abstract

The invention relates to an efficient extraction method of fructus galangae flower essential oil. The efficient extraction method comprises the following steps: selecting fresh young flowers of fructus galangae in the initial flowering stage as an extraction sample; carrying out wall breaking and homogenizing on the extracted sample; the wall breaking and homogenizing time is 2 minutes; and taking the extracted sample after wall breaking and homogenization, adding purified water according to a material-liquid ratio of 1: 3-1: 11, carrying out distillation extraction at 93-240 DEG C for 2-6 hours, collecting distillate, and drying to obtain the fructus galangae flower essential oil. According to the scheme provided by the invention, the relatively high biological activity of the fructus galangae flower essential oil can be maintained while the extraction rate of the fructus galangae flower essential oil is increased.

Description

Technical Field

[0001] The present application relates to the technical field of cardamom flower essential oil extraction, and in particular to a method for efficiently extracting cardamom flower essential oil. Background Art

[0002] Cardamom (scientific name Alpinia galanga (L.) Willd.), also known as Greater Galangal, is a perennial plant of the genus Alpinia in the ginger family. It is widely distributed and cultivated in tropical and subtropical regions of Asia and is an important local economic crop. Cardamom has the effects of regulating qi and relieving pain, strengthening the stomach and digestion, removing dampness and dispelling cold, and dispelling wind and relieving itching. It is mainly used to treat abdominal distension and pain, rheumatic joint pain, poisonous insect bites, skin itching, rashes, eczema, scabies, etc. Its tender stems can be boiled and dipped in seasonings or pickled before eating. Its tubers are essential seasoning spices for making the famous dish Tom Yum Goong. Its inflorescences are also boiled and pounded before eating. In addition, cardamom is also commonly used in cosmetics and daily chemical products. Cardamom is used as an active material for body care, such as skin creams, shampoos, conditioners and other skin care products and cosmetics. At present, the research on cardamom mainly focuses on the chemical composition analysis and related pharmacological activity research of cardamom fruits and tubers, and there is no report on the efficient extraction method of its flower essential oil.

[0003] Essential oils, also known as volatile oils and aromatic oils, are a class of volatile and fat-soluble oily substances contained in multiple parts of spice plants. Plant essential oils have a variety of physiological activities, including antibacterial, anti-inflammatory, antiviral, analgesic, anti-tumor, mosquito repellent, penetration-promoting, and antioxidant. Essential oils are found in the roots, stems, leaves, flowers, fruits, and seeds of spice plants. However, since the essential oil content in flowers is usually very low and the essential oil in flowers is usually highly volatile, the extraction of plant essential oils in flowers is the most difficult and the extraction rate is often very low. For example, the extraction rate of fresh rose essential oil by steam distillation is generally 0.02% to 0.05%, that is, at least 2-5 tons of fresh roses are needed to extract 1 kg of rose essential oil. The related art publication number CN113509409B discloses a method for preparing cardamom flower essential oil and its application. The method comprises taking cardamom flowers, adding an appropriate amount of ultrapure water, and performing steam distillation extraction for 4 hours. The distillate is collected, separated, and dried with anhydrous sodium sulfate to obtain cardamom flower essential oil. The extraction rate is 0.05% to 0.1%. It can be seen that the extraction technology of cardamom flower essential oil has not yet reached the optimal state, and its extraction rate still needs to be further improved to reduce the production cost of enterprises and obtain higher economic benefits. In addition, the essential oil extraction of most spice plants is only carried out in laboratories and cannot be industrialized and mass-produced.

[0004] Therefore, there is an urgent need to provide a method for extracting cardamom flower essential oil, which can improve the extraction rate of cardamom flower essential oil while maintaining high biological activity of cardamom flower essential oil and carry out industrial mass production. Summary of the invention

[0005] In order to solve or partially solve the problems existing in the related art, the present application provides an efficient extraction method of cardamom flower essential oil, which can improve the extraction rate of cardamom flower essential oil while maintaining high biological activity.

[0006] The present application provides an efficient method for extracting cardamom flower essential oil, comprising the following steps:

[0007] Cardamom flowers in the early flowering stage are broken and homogenized, and then distilled and extracted with water. The distillate is dried to obtain cardamom flower essential oil.

[0008] Optionally, the cell wall breaking and homogenization time is 2 minutes.

[0009] Optionally, the distillation extraction temperature is 93-240°C.

[0010] Optionally, the solid-liquid ratio (g:mL) of cardamom flower to water is 1:3 to 1:11; and the distillation extraction time is 2 to 6 hours.

[0011] Optionally, the solid-liquid ratio (g:mL) is 1:7 to 1:9; and the distillation extraction time is 5 to 6 hours.

[0012] Optionally, the solid-liquid ratio (g:mL) is 1:7; and the distillation extraction time is 5 hours.

[0013] The present application also provides cardamom flower essential oil prepared by the above-mentioned efficient extraction method.

[0014] The present application also provides a pilot method for an efficient extraction method of cardamom flower essential oil. The pilot method is as follows: the wall breaking and homogenization time is 2 minutes; the solid-liquid ratio of cardamom flower to water is 1:5 (g:mL); the distillation extraction time is 5 hours, and the extraction temperature is 93°C.

[0015] The technical solution provided by this application may have the following beneficial effects:

[0016] 1) In the present application, cardamom flowers are broken and homogenized to extract cardamom flower essential oil, thereby improving the extraction rate of cardamom flower essential oil, and the extraction rate can reach up to 0.50%.

[0017] 2) In the present application, cardamom flowers in the early flowering period are selected and the distillation extraction temperature is reasonably controlled to improve the extraction rate of cardamom essential oil while maintaining the biological activity of the cardamom essential oil. The extracted cardamom essential oil has significant antioxidant activity.

[0018] 3) The method of the present application was used for pilot testing. The instrument-related control conditions used in the pilot testing were not as sophisticated as those of the small laboratory extractor, and there were more unadjustable and uncontrollable factors. Using the method of the present application, the extraction rate of red cardamom flower essential oil in the pilot testing was still as high as 0.387%, and had significant antioxidant activity.

[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0021] Figure 1 This application shows the schematic diagram of the antioxidant activity of different concentrations of cardamom flower essential oil. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0023] Example 1

[0024] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0025] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering stage and use a wall breaking machine to break the wall and homogenize; the wall breaking time is 2 minutes; the early flowering stage, that is, the red cardamom flowers are from bud to the early flowering stage (the outer bracts fall off, within 7 days of flowering, the entire inflorescence is open to a maximum of one third);

[0026] S2, take the cardamom flower after wall breaking and homogenization, add pure water according to the solid-liquid ratio of 1:5 (g:mL), distill and extract at 220°C, steam distill and extract for 5 hours, collect the distillate, and obtain the cardamom flower essential oil after drying with anhydrous sodium sulfate. Essential oil extraction rate == essential oil mass (g) / sample raw material mass (g) × 100%.

[0027] The essential oil extraction rate was 0.50% ± 0.036%.

[0028] Example 2

[0029] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0030] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering period and use a wall-breaking machine to break the wall and homogenize; the wall-breaking time is 2 minutes;

[0031] S2. Take the cardamom flower after wall breaking and homogenization, add pure water according to the solid-liquid ratio of 1:3, 1:5, 1:7, 1:9, 1:11, distill and extract at 220°C, steam distill for 4 hours, collect the distillate, and dry it with anhydrous sodium sulfate to obtain cardamom flower essential oil. Each solid-liquid ratio test was repeated 4 times. The test results are shown in Table 1

[0032] Table 1 Extraction rate of cardamom essential oil at different solid-liquid ratios

[0033]

[0034] As shown in Table 1, after comparing the mean values, the extraction rate of the solid-liquid ratio of 1:3 was 0.39±0.022, which was significantly lower than that of the other solid-liquid ratio groups. The essential oil extraction rates of the other solid-liquid ratios of 1:5, 1:7, 1:9 and 1:11 were all around 0.50, with no significant difference.

[0035] Example 3

[0036] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0037] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering period and use a wall-breaking machine to break the wall and homogenize; the wall-breaking time is 2 minutes;

[0038] S2, take the cardamom flower after broken wall homogenization, add pure water according to the solid-liquid ratio of 1:7, distillation extraction temperature 200 ℃, steam distillation extraction essential oil time is set to 2, 3, 4, 5, 6 hours, collect distillate, and obtain cardamom flower essential oil after drying with anhydrous sodium sulfate. Each distillation time is repeated 4 times. The test results are shown in Table 2.

[0039] Table 2 Extraction rate of cardamom essential oil at different distillation extraction times

[0040]

[0041]

[0042] It can be seen from Table 2 that different distillation extraction times have an impact on the essential oil extraction rate. When the distillation extraction time is 5 hours, the essential oil extraction rate is 0.48%±0.018%, and when the distillation extraction time is 6 hours, the essential oil extraction rate is 0.47%±0.060%. When other distillation extraction times are used, the essential oil extraction rates are all below 0.47%±0.060%.

[0043] Example 4

[0044] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0045] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering period and use a wall-breaking machine to break the wall and homogenize; the wall-breaking time is 2 minutes;

[0046] S2, take the cardamom flower after wall breaking and homogenization, add pure water according to the solid-liquid ratio of 1:6, distill and extract at 220°C, steam distill and extract for 4 hours, collect the distillate, and obtain cardamom flower essential oil after drying with anhydrous sodium sulfate. Each degree of crushing is repeated 4 times.

[0047] Comparative Example 1

[0048] The difference between Comparative Example 1 and Example 4 is that in step S1, the cardamom flowers are chopped into pieces of 2 cm, 1 cm, 0.5 cm, and 0.25 cm respectively, and other conditions remain unchanged. The test results of Example 4 and Comparative Example 1 are shown in Table 3.

[0049] Table 3 Extraction rate of cardamom essential oil at different crushing degrees

[0050]

[0051] As shown in Table 3, the maximum essential oil extraction rate of the extracted sample by shredding is 0.22%, which is much lower than the essential oil extraction rate of the broken wall homogenization in Example 4. It can be seen that the broken wall homogenization method can significantly improve the essential oil extraction rate compared with shredding the extracted sample.

[0052] Example 5

[0053] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0054] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering period, and chop them according to literature and patent reports;

[0055] S2. Take the chopped cardamom flowers, add purified water according to the solid-liquid ratio of 1:3, distill and extract at a temperature of 200° C. for 4 hours, collect the distillate, and dry it with anhydrous sodium sulfate to obtain cardamom flower essential oil. Repeat each degree of crushing 4 times.

[0056] Cardamom essential oil DPPH antioxidant test:

[0057] Add 100 μL of sample extracts of different concentrations (10 mg / ml to 0.078125 mg / ml, 2-fold dilution, 8 gradients) to a 96-well plate, then add 100 μL of DPPH solution (100 umoL / L), react in the dark for 30 minutes, and then measure the absorbance at 517. Use anhydrous ethanol as a blank control and VC as a positive control to detect the antioxidant activity of the extract. Do 3 replicates for each concentration and take the average value. DPPH free radical scavenging rate calculation formula: DPPH free radical scavenging rate = (D0-D1) / A0*100%.

[0058] Wherein, D1 is the absorbance after the reaction between plant essential oil and DPPH solution;

[0059] D0 is the absorbance after the reaction of anhydrous ethanol and DPPH solution.

[0060] Comparative Example 2

[0061] The difference between Comparative Example 2 and Example 5 is that the cardamom flowers in step S1 are cardamom flowers in full flowering period and late flowering period; the full flowering period is the 8th to 15th day of the flowering of the cardamom flowers (one-third of the whole inflorescence is in full bloom to at most fully bloomed); the late flowering period is the 16th day of the flowering of the cardamom flowers to the early stage of young fruit (the whole inflorescence is in full bloom, and one-third of the inflorescence has a small amount of young fruit); other conditions remain unchanged.

[0062] The experimental results of Example 5 and Comparative Example 2 are shown in Tables 4 and 5.

[0063] Table 4 Extraction rate of essential oil from cardamom flowers at different flowering periods

[0064]

[0065]

[0066] According to the test results in Table 4, the flowering period with the highest extraction rate of cardamom flower essential oil at different flowering periods is the early flowering period.

[0067] Table 5 Antioxidant activity of cardamom flowers at different flowering stages

[0068]

[0069] Note: IC of DPPH free radical scavenging 50 The lower the value, the stronger the antioxidant activity.

[0070] Example 6

[0071] An efficient method for extracting cardamom flower essential oil comprises the following steps:

[0072] S1. Weigh 300 g of fresh young flowers of red cardamom in the early flowering period and use a wall-breaking machine to break the wall and homogenize; the wall-breaking time is 2 minutes;

[0073] S2. Take the cardamom flower after wall breaking and homogenization, add pure water according to the solid-liquid ratio of 1:7, and steam distill for 4 hours. The distillation extraction temperatures are 160°C, 180°C, 200°C, 220°C, and 240°C, respectively. Collect the distillate, and dry it with anhydrous sodium sulfate to obtain cardamom flower essential oil. Each degree of crushing is repeated 4 times.

[0074] The steps of the DPPH antioxidant test of cardamom flower essential oil are the same as those of Example 5 above.

[0075] The experimental results of Example 6 are shown in Tables 6 and 7.

[0076] Table 6 Extraction rate of cardamom essential oil at different heating extraction temperatures

[0077]

[0078] According to the test results in Table 6, the temperature at which the cardamom flower essential oil extraction rate is highest is 200°C.

[0079] Table 7 Antioxidant activity of cardamom essential oil at different heating extraction temperatures

[0080]

[0081] Note: IC of DPPH free radical scavenging 50 The lower the value, the stronger the antioxidant activity.

[0082] According to the experimental results in Table 7, as the heating extraction temperature increases from 160℃ to 240℃, the DPPH half inhibition concentration IC 50 The value increased from 0.38mg / mL to 0.88mg / mL. This indicates that the lower the extraction temperature, the better the antioxidant activity of cardamom essential oil. Combining the data in Tables 3, 4, 5, 6 and 7, we found that for samples of cardamom flowers at the early flowering stage, with the same extraction temperature of 200℃ and extraction time of 4 hours, wall breaking and crushing significantly increased the extraction rate of cardamom essential oil, with extraction rates of 0.46% and 0.09% respectively. However, the effect on the antioxidant activity of the essential oil was not significant, and its IC 50 The values ​​were 0.68mg / mL and 0.61mg / mL respectively. Since many active substances in essential oils are heat-sensitive, under the premise of ensuring a certain essential oil extraction rate, a lower heating extraction temperature can be used to obtain cardamom flower essential oil with better activity.

[0083] Example 7: Pilot test of efficient extraction of cardamom flower essential oil

[0084] Combined with the previous data analysis, the above extraction method was slightly modified. The cardamom flowers in the early flowering period were broken and homogenized for 2 minutes, and then put into a 400L medium-sized steam extraction equipment. According to the material-liquid ratio of 1:5, the extraction temperature was heated to 93°C and distilled for 5 hours to extract the cardamom flower essential oil. The extraction rate was 0.387%. According to the DPPH antioxidant test method in the above test example 5, the antioxidant activity of the sample was tested and compared with common essential oils such as rose. The specific results are as follows Figure 1 And as shown in Table 6.

[0085] Table 8 Comparison of DPPH antioxidant activity of cardamom essential oil and common essential oils

[0086]

[0087] Note: IC of DPPH free radical scavenging 50 The lower the value, the stronger the antioxidant activity.

[0088] according to Figure 1 The test results in Table 8 show that the cardamom essential oil extracted by the method of the present application using a 400L medium-sized steam distillation extraction device has significant antioxidant activity, IC 50 The value is 0.258±0.003mg / mL, and its antioxidant activity is stronger than the commonly used essential oils tested, such as rose, ylang-ylang, lavender, white sandalwood, jasmine, benzoin, etc. The control conditions of the 400L medium-sized steam distillation extraction equipment are not as fine as the 5L small-scale extractor in the laboratory, and there are more unadjustable and uncontrollable factors. Using the method of the present application, the extraction rate of red cardamom flower essential oil in the pilot test is 0.387%, which is lower than the 0.5% of the laboratory test, but it is 3.5-7.7 times higher than the extraction rate of red cardamom flower essential oil reported in the relevant literature and patents (0.05-0.11%), while still maintaining significant antioxidant activity.

[0089] Free radicals are one of the main factors causing oxidation and aging. Discovering natural antioxidants from plant extracts has always been a global research hotspot in the fields of biology and hospital. According to incomplete statistics, except for rose essential oil, essential oils such as ylang-ylang, lavender, sandalwood, jasmine, and benzoin, which are commonly sold on the global market, have not been found to have significant antioxidant activity. In addition, since plant essential oils are heat-sensitive and volatile, many active substances will change or oxidize during the steam heating and distillation extraction process, resulting in a decrease in related activity. How to ensure that the essential oil extraction rate has a high antioxidant and other biological activity at a high extraction rate is a major challenge for the efficient extraction of plant essential oils.

[0090] In the present application, the cardamom flowers are broken and homogenized to significantly improve the extraction rate of the cardamom essential oil. Cardamom flowers in the early flowering period are selected and the distillation extraction temperature is reasonably controlled. The extraction rate of the cardamom essential oil is improved while the biological activity of the cardamom essential oil is maintained. The extracted cardamom essential oil has significant antioxidant activity.

[0091] Based on the above embodiments and comparative examples, it is shown that the method of the present application not only ensures a higher extraction rate, but also well guarantees the antioxidant activity of cardamom flower essential oil, which is beneficial to reducing production costs, improving economic value, and promoting the development of cardamom flower essential oil related industries.

[0092] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An efficient method for extracting cardamom flower essential oil, characterized in that: The following steps are involved: Cardamom flowers in the early flowering stage are broken and homogenized, and then distilled and extracted with water. The distillate is dried to obtain cardamom flower essential oil.

2. The efficient extraction method according to claim 1, characterized in that The cell wall breaking and homogenization time is 2 minutes.

3. The efficient extraction method according to claim 1, characterized in that The distillation extraction temperature is 93-240°C.

4. The efficient extraction method according to claim 1, characterized in that The solid-liquid ratio (g:mL) of the cardamom flower and water is 1:3 to 1:11; and the distillation extraction time is 2 to 6 hours.

5. The efficient extraction method according to claim 4, characterized in that: The solid-liquid ratio (g:mL) is 1:7 to 1:9; and the distillation extraction time is 5 to 6 hours.

6. The efficient extraction method according to claim 5, characterized in that: The solid-liquid ratio (g:mL) is 1:7; and the distillation extraction time is 5 hours.

7. Cardamom flower essential oil prepared according to the efficient extraction method according to any one of claims 1 to 6.

8. A pilot test method for the efficient extraction method of cardamom flower essential oil as claimed in claim 1, characterized in that: The pilot method is as follows: the wall breaking and homogenization time is 2 minutes; the solid-liquid ratio of cardamom flower to water is 1:5 (g:mL); the distillation extraction time is 5 hours, and the extraction temperature is 93°C.

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