Extraction method and analysis method of volatile flavor components in natural plants

Abstract

The invention belongs to the technical field of material test analysis methods, and particularly relates to an extraction method and an analysis method of volatile aroma components in natural plants. The method for extracting the volatile aroma components in the natural plants comprises the following steps: putting a natural plant sample into a distillation container in a solvent-assisted flavor evaporation device, putting an extraction solvent into a funnel, and extracting the volatile aroma components by adopting a solvent-assisted flavor evaporation technology, during extraction, an extraction solvent is added into the distillation container, and a sample and the extraction solvent in the distillation container are in a stirring state. On the basis of solvent-assisted flavor evaporation, a natural plant sample is directly loaded into a distillation container, so that the volatile flavor components are extracted from the sample and an extraction solvent in the distillation container in a stirring state, a solvent extraction step is not needed, and the loss of the volatile flavor components caused in a pretreatment process is avoided; moreover, the method is simple and convenient to operate, long in extraction time and high in extraction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of material testing and analysis methods, and in particular to an extraction method and an analysis method for volatile aroma components in natural plants. Background Art

[0002] The extraction of volatile aroma components from natural plants is of great significance in the fields of food, agriculture, medicine, flavors and fragrances, and the selection of appropriate extraction methods is crucial for the extraction of volatile aroma components from natural plants. At present, the main extraction methods for volatile aroma components from natural plants include simultaneous distillation extraction, headspace solid phase microextraction, supercritical fluid extraction, and solvent-assisted flavor evaporation.

[0003] Solvent-assisted flavor evaporation (SAFE) is a method for gently and comprehensively extracting volatile substances from complex matrices. It evaporates volatile components under high vacuum conditions without the need for high temperature conditions, which can effectively reduce the loss of heat-sensitive and volatile components in the sample. The flavor of the resulting extract is consistent with the sample, and the aroma is natural and realistic.

[0004] At present, the application of solvent-assisted flavor evaporation is mainly aimed at liquid samples, and SAFE extraction technology is less used in solid samples, and the solid samples to be extracted need to undergo a pretreatment process of solvent extraction. In October 2023, Mo Haoran et al. published the article "Headspace solid phase microextraction combined with solvent-assisted flavor evaporation to analyze the volatile components of seedless sea buckthorn and their aroma contribution". The volatile components of seedless sea buckthorn were analyzed by headspace solid phase microextraction and liquid-liquid extraction combined with solvent-assisted flavor evaporation (SAFE). In the SAFE extraction part, the sea buckthorn samples were pretreated by juicing and dichloromethane liquid-liquid extraction.

[0005] However, the pretreatment process of solvent extraction may cause the loss of some aroma components, and further after SAFE extraction, it cannot fully reflect the aroma information of the original sample, making the product aroma unnatural or different from the original sample, and the extracted volatile aroma components cannot accurately reflect the aroma information of the original sample. The extraction results are inaccurate, and the pretreatment process makes the extraction process time-consuming and cumbersome. Summary of the invention

[0006] The purpose of the present invention is to provide a method for extracting volatile aroma components from natural plants, so as to solve the problem of poor accuracy of extraction results when extracting volatile aroma components from natural plant samples in the prior art.

[0007] The second object of the present invention is to provide a method for analyzing volatile aroma components in natural plants, so as to solve the problem of poor accuracy of test results in the prior art when testing and analyzing volatile aroma components in natural plant samples.

[0008] In order to solve the above technical problems, the technical solution of the method for extracting volatile aroma components from natural plants of the present invention is: A method for extracting volatile aroma components from natural plants comprises the following steps: placing a natural plant sample in a distillation container in a solvent-assisted flavor evaporation device, placing an extraction solvent in a funnel, extracting the volatile aroma components using a solvent-assisted flavor evaporation technique, adding the extraction solvent into the distillation container during extraction, and the sample and the extraction solvent in the distillation container are in a stirring state.

[0009] The present invention improves the prior art and provides a method for extracting volatile aroma components from natural plants. On the basis of solvent-assisted flavor evaporation, the natural plant sample is directly loaded into a distillation container, and the extraction solvent in a funnel enters the distillation container. The sample and the extraction solvent in the distillation container are in a stirring state to extract the volatile aroma components. The stirring helps the sample to be heated evenly in the distillation container, and the extraction solvent dripping from the funnel can also be evenly mixed with the sample, thereby improving the extraction efficiency of the sample.

[0010] The extraction method of the present invention does not require the step of solvent extraction, and directly places the sample in a SAFE device for extraction, thereby avoiding the loss of volatile aroma components caused by the pretreatment process, retaining the sample aroma components to a greater extent, being able to fully reflect the aroma information of the original sample, and truly restoring the aroma characteristics of the raw materials, so that the extracted volatile aroma components can accurately reflect the aroma information of the original sample, thereby improving the accuracy of the extraction result, and the operation is simple, the extraction time is short, and the extraction efficiency is high.

[0011] In order to further increase the extraction amount of volatile aroma components such as esters, aldehydes and alcohols in natural plants, preferably, water or a surfactant solution is sprayed on the surface of the natural plant sample before extraction, the solid-liquid ratio of the natural plant sample to water or the surfactant solution is 1: (1-3) g / mL, and the concentration of the surfactant solution is 1.0-2.0 mg / mL.

[0012] In order to further increase the extraction amount of volatile aroma components in natural plants, preferably, the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, and Tween 80.

[0013] In order to further improve the extraction efficiency of volatile aroma components, preferably, the water bath temperature of the solvent-assisted flavor evaporation device is 20-40° C., and the system vacuum degree of the solvent-assisted flavor evaporation device is 10-3 ~10 -6 Pa; the extraction time is 2 to 5 hours. By utilizing the property of reducing the boiling point of the compound under vacuum conditions, the volatile aroma components are effectively released under low temperature conditions, which can effectively remove the interference of non-volatile compounds. By extracting under low temperature and high vacuum conditions, the extraction efficiency of volatile aroma components directly extracted from natural plant samples is improved.

[0014] In order to further extract the volatile aroma components in natural plants more completely, preferably, the stirring speed of the sample and the extraction solvent in the distillation container is 400-1000r / min, and the addition speed of the extraction solvent is 50-100 drops / min. By controlling the stirring speed and the addition speed of the extraction solvent, it is helpful for the sample to be heated evenly and mixed evenly with the extraction solvent, so that the volatile aroma components in the sample can be extracted.

[0015] In order to further improve the extraction efficiency of natural plants, preferably, the solid-liquid ratio of the natural plant sample to the extraction solvent is 1: (5~20) g / mL.

[0016] In order to further increase the extraction types and extraction amounts of volatile components of natural plants, preferably, the natural plant is selected from one of tobacco leaves, tea leaves, osmanthus, hops, tangerine peel, prickly ash, roxburghii, and rapeseed; the extraction solvent is an aqueous solution of phenethyl acetate or a dichloromethane solution of phenethyl acetate, wherein the concentration of phenethyl acetate in the extraction solvent is (0.9~1.1) μg / mL.

[0017] The technical scheme of the method for analyzing volatile aroma components in natural plants of the present invention is: A method for analyzing volatile aroma components in natural plants comprises the following steps: after extracting volatile aroma components in natural plants using the extraction method, the extract in the collection container of a solvent-assisted flavor evaporation device is made into a test liquid, and the volatile aroma components in the test liquid are tested and analyzed.

[0018] The method for analyzing volatile aroma components in natural plants provided by the present invention can greatly improve the types and contents of volatile aroma components detected during test analysis by adopting the extraction method for volatile aroma components in natural plants, greatly improve the detection accuracy of volatile aroma components in natural plants, and does not require liquid phase extraction pretreatment of samples, is simple to operate, saves detection time, and has high detection efficiency.

[0019] In order to further improve the separation effect of each component in the volatile aroma component, preferably, the test analysis is GC-MS analysis, and the chromatographic column used in the GC-MS analysis is a DB-5MS chromatographic column.

[0020] In order to further improve the detection accuracy of volatile aroma components, preferably, the chromatographic conditions during the GC-MS analysis are: the injection port temperature is 260~270℃; the temperature rise program is from 50~60℃ to 250~260℃ at 2~3℃ / min; the sample is injected in a splitless manner at 260~270℃, and the injection volume is 1~2 μL; the mass spectrometry conditions during the GC-MS analysis are: the ion source temperature is 230~240℃, the transmission line temperature is 270~280℃; the ionization voltage is 70~80 eV, and the scanning range is 33~455amu. DETAILED DESCRIPTION

[0021] The technical conception of the method for extracting volatile aroma components from natural plants of the present invention is as follows: A method for extracting volatile aroma components from natural plants comprises the following steps: placing a natural plant sample in a distillation container in a solvent-assisted flavor evaporation device, placing an extraction solvent in a funnel, extracting the volatile aroma components using a solvent-assisted flavor evaporation technique, adding the extraction solvent into the distillation container during extraction, and the sample and the extraction solvent in the distillation container are in a stirring state.

[0022] The existing SAFE technology, when extracting volatile aroma components from solid samples, first performs liquid phase extraction on the solid sample to obtain an extract, and then performs solvent-assisted flavor evaporation on the extract to extract the volatile aroma components. The method for extracting volatile aroma components from natural plants provided by the present invention is to perform evaporative extraction on the solid sample during the liquid phase extraction process, and directly use the extract obtained by the liquid phase extraction as an auxiliary evaporation solvent during the solvent-assisted flavor evaporation, thereby reducing the loss of volatile aroma components of the solid sample caused by the prior art of first extracting and then extracting, and can retain the aroma components of the sample to a greater extent, can fully reflect the aroma information of the original sample, and truly restore the aroma characteristics of the raw material, so that the extracted volatile aroma components can accurately reflect the aroma characteristics of the original sample, thereby improving the accuracy of the extraction result; and the method is simple to operate, short extraction time, and high extraction efficiency.

[0023] In a specific embodiment, the natural plant sample is equilibrated in a constant temperature and humidity chamber (temperature 22-25° C., humidity 60-70%) for 24-36 h before extraction.

[0024] In a specific embodiment, the natural plant sample is obtained by crushing or cutting the natural plant, the mesh number of the natural plant sample obtained by crushing is not less than 40 meshes, and the size of the natural plant sample obtained by cutting is (4~5) mm × (4~5) mm.

[0025] In a specific embodiment, the distillation container of the solvent-assisted flavor evaporation device is immersed in a constant temperature water bath, and the extraction temperature of the sample is controlled by controlling the water bath temperature of the constant temperature water bath; the collection container is immersed in liquid nitrogen, and liquid nitrogen is also added to the cold trap of the solvent-assisted flavor evaporation device.

[0026] In a specific embodiment, when the natural plant sample is cut or crushed without spraying water or surfactant on the surface, a high vacuum valve is set between the vacuum pump and the evaporation device during the extraction of volatile aroma components using the SAFE device. When evacuating the vacuum, the opening of the high vacuum valve is controlled to first evacuate the gas at a lower gas flow rate to prevent the solid sample powder from flying, and then the gas flow rate is slowly increased until the system vacuum degree of the SAFE device reaches the set vacuum degree. At this time, the SAFE device enters a stable extraction stage.

[0027] A method for analyzing volatile aroma components in natural plants comprises the following steps: after extracting volatile aroma components in natural plants using the extraction method, the extract in the collection container of a solvent-assisted flavor evaporation device is made into a test liquid, and the volatile aroma components in the test liquid are tested and analyzed.

[0028] In a specific embodiment, the test analysis can be GC-MS, GC-O-MS, GC-IMS, etc.

[0029] In a specific embodiment, the test liquid is the extract in the collection container that is naturally melted at room temperature and then concentrated; when the extraction solvent contains water or water is sprayed on the sample surface, the extract is extracted with an organic solvent after natural melting to obtain the extract, and the extract is dried with anhydrous Na2SO4 and then concentrated to obtain the test liquid; the organic solvent is selected from one or more of dichloromethane, acetonitrile, and methanol.

[0030] In a specific embodiment, the concentration can be nitrogen blowing concentration, rotary evaporation concentration, Weissler distillation concentration, etc.

[0031] The embodiments of the present invention are further described below in conjunction with specific examples. The chemical reagents involved in the following examples are all commercially available conventional products unless otherwise specified.

[0032] 1. Specific embodiments of the method for extracting volatile aroma components from natural plants of the present invention Example 1 The extraction method of volatile aroma components in the cigar tobacco leaves of the present embodiment is as follows: 1) Sample preparation: 10.0 g of cigar tobacco leaves were cut into pieces of 5 mm × 5 mm to obtain cigar tobacco leaf samples, and then the samples were placed in a constant temperature and humidity chamber (temperature 22 °C, humidity 60%) for 24 h for equilibration.

[0033] 2) Extraction: Accurately weigh 5.0 g of the cigar tobacco leaf sample after equilibrium in step 1) into the distillation flask on the left side of the SAFE device, and add a stirring magnet. Add 50 mL of distilled water (containing phenylethyl acetate, concentration 0.91 μg / mL) into the glass funnel as the extraction solvent. Set the circulating water bath temperature and the constant temperature water bath of the SAFE device to 40 °C, set the stirring speed to 400 r / min, add liquid nitrogen to the cold trap, turn on the molecular turbo pump, and wait until the system vacuum reaches 1×10 -3 Pa, slowly open the stopcock of the dropping funnel and control the flow rate of the extraction solvent to 100 drops / min, so that it drips slowly and evenly into the distillation flask. The extraction time is 2 h.

[0034] Example 2 The extraction method of volatile aroma components in the green Zanthoxylum bungeanum of the present embodiment is as follows: 1) Sample preparation: Grind the green peppercorns with a grinder and pass through a 40-mesh sieve to obtain the green peppercorn sample for later use.

[0035] 2) Extraction: Accurately weigh 5.0 g of the green pepper sample in step 1) into the distillation flask on the left side of the SAFE device, add a stirring magnet, add 25 mL of dichloromethane (containing phenylethyl acetate, concentration 1.02 μg / mL) into the glass funnel as the extraction solvent, set the circulating water bath temperature and the constant temperature water tank of the SAFE device to 20 °C, set the stirring speed to 1000 r / min, and add liquid nitrogen to the cold trap. In order to prevent the crushed green pepper sample from scattering into the system, set a high vacuum valve between the SAFE device and the vacuum pump. After closing the high vacuum valve, turn on the molecular turbo pump and wait until the system vacuum is stable to 1×10 -6 Pa, slowly open the high vacuum valve until the device system is fully connected to the vacuum pump, then slowly open the dropping funnel stopcock, control the extraction solvent flow rate to 50 drops / min, and allow it to drip slowly and evenly into the distillation flask. The extraction time is 2 h.

[0036] Example 3 The extraction method of volatile aroma components in the sweet osmanthus of the present embodiment is as follows: 1) Sample preparation: Take 10.0 g of osmanthus and cut it into pieces to obtain an osmanthus sample. Spray 10 mL of sodium dodecyl sulfate solution (concentration of 1.0 mg / mL) evenly on the surface of the osmanthus sample. After spraying, place the osmanthus sample in a constant temperature and humidity chamber (temperature 22 ℃, humidity 60%) for 24 h for equilibrium before use.

[0037] 2) Extraction: Accurately weigh 5.0 g of the osmanthus sample balanced in step 1) into the distillation flask on the left side of the SAFE device, add a stirring magnet, add 100 mL of dichloromethane (containing phenylethyl acetate, concentration 1.02 μg / mL) into the glass funnel as the extraction solvent, set the circulating water bath temperature and the constant temperature water tank of the SAFE device to 30 °C, set the stirring speed to 800 r / min, add liquid nitrogen to the cold trap, turn on the molecular turbo pump, and wait until the system vacuum reaches 1×10 -6 Pa, slowly open the stopcock of the dropping funnel and control the flow rate of the extraction solvent to 50 drops / min, so that it drips slowly and evenly into the distillation flask. The extraction time is 2 h.

[0038] Example 4 The method for extracting volatile aroma components from cigar tobacco leaves in this example is basically the same as that in Example 1, except that: in step 1), 10 mL of distilled water (solid-liquid ratio 1:1 g / mL) is sprayed on the surface of 10.0 g of cigar tobacco leaf sample, and then the sample is placed in a constant temperature and humidity chamber (temperature 22° C., humidity 60%) for 24 h for equilibrium.

[0039] Example 5 The method for extracting volatile aroma components from cigar tobacco leaves in this embodiment is basically the same as that in Example 1, except that: in step 1), 20 mL of distilled water (solid-liquid ratio 1:2 g / mL) is sprayed on the surface of 10.0 g of cigar tobacco leaf sample, and then the sample is placed in a constant temperature and humidity chamber (temperature 22°C, humidity 60%) for equilibration for 24 h before use.

[0040] Example 6 The method for extracting volatile aroma components from cigar tobacco leaves in this embodiment is basically the same as that in Example 1, except that: in step 1), 30 mL of distilled water (solid-liquid ratio 1:3 g / mL) is sprayed on the surface of 10.0 g of cigar tobacco leaf sample, and then the sample is placed in a constant temperature and humidity chamber (temperature 22°C, humidity 60%) for equilibration for 24 h before use.

[0041] 2. Specific embodiments of the method for analyzing volatile aroma components in natural plants of the present invention Example 7 The analysis method of the volatile aroma components in the cigar tobacco leaves of this embodiment is as follows: 1) Preparation of the test solution: After the extraction of volatile aroma components from cigar tobacco leaves using the extraction method of Example 1, the extract in the collection bottle of the solvent-assisted flavor evaporation device was naturally melted at room temperature, extracted three times with 15 mL of dichloromethane, and the three extracts were combined, dried overnight with anhydrous Na2SO4, and concentrated to 1 mL by nitrogen blowing to obtain the test solution.

[0042] 2) GC-MS analysis: The volatile aroma components in the test liquid were analyzed by GC-MS. The chromatographic column used in GC-MS analysis was DB-5MS chromatographic column (60 m×0.25 mm×0.25μm). The chromatographic conditions for GC-MS analysis were: injection port temperature was 270℃; temperature program: from 50℃ to 260℃ at 2℃ / min; injection was performed at 270℃ in splitless mode, and the injection volume was 1 μL; the mass spectrometry conditions for GC-MS analysis were: ion source temperature was 230℃, transfer line temperature was 280℃; ionization voltage was 70 eV, and scanning range was 33~455 amu; the GC-MS results were searched using the NIST17 spectral library, and compounds with a matching degree higher than 85% were selected for identification. The identified compounds were semi-quantitatively analyzed using the internal standard method.

[0043] A total of 50 volatile aroma components were identified in cigar tobacco leaves, with a total volatile content of 38383.03 ng / g.

[0044] In other embodiments, after the extraction of volatile aroma components in cigar leaves is completed using the extraction methods of Examples 4-6, the volatile aroma components in the cigar leaves are analyzed by GC-MS using the above method.

[0045] After using the extraction method of Example 4, the GC-MS analysis results of the volatile aroma components are as follows: a total of 44 volatile aroma components in cigar tobacco leaves were identified, and the total amount of volatiles was 16080.75 ng / g.

[0046] Example 8 The analytical method of volatile aroma components in the green Zanthoxylum bungeanum of the present embodiment is as follows: 1) Preparation of the test solution: After the extraction of volatile flavor components in green pepper by the extraction method of Example 2 is completed, the extract in the collection bottle of the solvent-assisted flavor evaporation device is naturally melted at room temperature, and then concentrated to 1 mL by nitrogen blowing to obtain the test solution.

[0047] 2) GC-MS analysis: The volatile aroma components in the test liquid were analyzed by GC-MS. The chromatographic column used in GC-MS analysis was DB-5MS chromatographic column (60 m×0.25 mm×0.25μm). The chromatographic conditions for GC-MS analysis were: injection port temperature was 270℃; temperature program: from 50℃ to 260℃ at 2℃ / min; injection was performed at 270℃ in splitless mode, and the injection volume was 1 μL; the mass spectrometry conditions for GC-MS analysis were: ion source temperature was 230℃, transfer line temperature was 280℃; ionization voltage was 70 eV, and scanning range was 33~455 amu; the GC-MS results were searched using the NIST17 spectral library, and compounds with a matching degree higher than 85% were selected for identification. The identified compounds were semi-quantitatively analyzed using the internal standard method.

[0048] A total of 55 volatile aroma components of green pepper were identified, with a total volatile content of 1523.62 ng / g.

[0049] Example 9 The analysis method of volatile aroma components in the sweet osmanthus of the present embodiment is as follows: 1) Preparation of the test solution: After the extraction of volatile aroma components in osmanthus fragrans by the extraction method of Example 3 is completed, the extract in the collection bottle of the solvent-assisted flavor evaporation device is naturally melted at room temperature, and then concentrated to 1 mL by nitrogen blowing to obtain the test solution.

[0050] 2) GC-MS analysis: The volatile aroma components in the test liquid were analyzed by GC-MS. The chromatographic column used in GC-MS analysis was DB-5MS chromatographic column (60 m×0.25 mm×0.25μm). The chromatographic conditions for GC-MS analysis were: injection port temperature was 270℃; temperature program: from 50℃ to 260℃ at 2℃ / min; injection was performed at 270℃ in splitless mode, and the injection volume was 1 μL; the mass spectrometry conditions for GC-MS analysis were: ion source temperature was 230℃, transfer line temperature was 280℃; ionization voltage was 70 eV, and scanning range was 33~455 amu; the GC-MS results were searched using the NIST17 spectral library, and compounds with a matching degree higher than 85% were selected for identification. The identified compounds were semi-quantitatively analyzed using the internal standard method.

[0051] A total of 58 volatile aroma components of Osmanthus fragrans were identified, with a total volatile content of 1803.50 ng / g.

[0052] 3. Comparison Comparative Example 1 In this comparative example, cigar tobacco leaves are subjected to ultrasound-assisted extraction-solvent-assisted flavor evaporation to extract volatile flavor components. The extraction method of volatile flavor components in cigar tobacco leaves is as follows: 1) Sample preparation: 10.0 g of cigar tobacco leaves were placed in a 40°C oven for 30 min. The dried tobacco leaves were crushed in a grinder and passed through a 40-mesh sieve. The obtained cigar tobacco leaf samples were placed in a constant temperature and humidity chamber (temperature 22°C, humidity 60%) for 24 hours for standby use.

[0053] 2) Ultrasonic-assisted extraction-solvent-assisted flavor evaporation extraction: Accurately weigh 5.0 g of the cigar tobacco leaf sample balanced in step 1) into a beaker, add 50 mL of distilled water (containing phenylethyl acetate, concentration 0.91 μg / mL), extract for 30 min at an ultrasonic power of 600 W, and use a suction filtration device to achieve solid-liquid separation after the extraction. The obtained extract was added to the glass funnel of the SAFE device. The circulating water bath temperature and the constant temperature water bath of the SAFE device were set to 40 °C. Liquid nitrogen was added to the cold trap, and the molecular turbo pump was turned on. When the system vacuum reached 1×10 -3 Pa, slowly open the stopcock of the dropping funnel and control the flow rate of the solvent so that it drips slowly and evenly into the distillation flask. The extraction time is 2 h.

[0054] The volatile aroma components were tested and analyzed using the analysis method for volatile aroma components in cigar tobacco leaves of Example 7. The test and analysis results showed that a total of 48 volatile aroma components were identified in cigar tobacco leaves, and the total amount of volatiles was 15123.44 ng / g.

[0055] Compared with the extraction method provided by the present invention, the types of volatile aroma components that can be identified and the total amount of volatiles are reduced by using the ultrasound-assisted extraction-solvent-assisted flavor evaporation extraction method of this comparative example.

[0056] IV. Experimental Examples The GC-MS quantitative test results of volatile aroma components in natural plants using different extraction methods are shown in Table 1.

[0057] Table 1 GC-MS quantitative test results of volatile aroma components in cigar tobacco leaves of Examples 1, 4-6 and Comparative Example 1

[0058] Note: “-” indicates not detected, “ / ” indicates data not shown.

[0059] From Table 1 and the above analysis results, it can be seen that compared with ultrasound-assisted extraction-solvent-assisted flavor evaporation (Comparative Example 1), the extraction method of Example 1 can identify more types of volatile aroma components and a higher total amount of volatiles. Although the types of volatile aroma components in Example 4 are lower than those in Comparative Example 1, its total amount of volatiles is still higher than that in Comparative Example 1; from the compound information identified in Example 1 and Comparative Example 1 in Table 1, it can be seen that the difference in the total amount of compounds between the two is mainly reflected in terpenes and alkaloids, such as: neophytadiene, nicotine and diene nicotine. These compounds help to enhance the taste and aroma of cigar tobacco leaves, while reducing the irritation and bitterness of tobacco leaves, making the aroma of tobacco leaves softer.

[0060] After the cigar tobacco leaf samples were treated with water spray (Examples 4-6), although the types of volatile aroma components in the cigar tobacco leaves were identified to be reduced, the total content of volatile aroma components was also reduced. However, it is worth noting that, from the information of some compounds identified in Examples 1 and 4-6 in Table 1, more types of ester compounds, such as butyl propionate, γ-butyrolactone, 2-ethylhexyl acetate, and ethyl octanoate, can be identified in the cigar tobacco leaf samples after water spray treatment, and the relative content of aldehyde compounds increases with the increase of the amount of water sprayed on the tobacco leaves, and the relative content of ester and alcohol compounds increases first, then decreases, and finally increases with the increase of the amount of water sprayed on the tobacco leaves. This shows that during the extraction process, the sprayed water can carry the compounds in a part of the tobacco leaf samples into the distillation head of the device, thereby improving the extraction efficiency of some compounds. In the future, according to this rule, the plant samples can be sprayed with solvents or surfactants before extraction to improve the extraction effect of specific types of compounds.

[0061] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for extracting volatile aroma components from natural plants, characterized in that: The method comprises the following steps: placing a natural plant sample in a distillation container in a solvent-assisted flavor evaporation device, placing an extraction solvent in a funnel, extracting volatile flavor components using a solvent-assisted flavor evaporation technique, adding the extraction solvent into the distillation container during extraction, and the sample and the extraction solvent in the distillation container are in a stirring state.

2. The method for extracting volatile aroma components from natural plants according to claim 1, characterized in that: Before extraction, water or surfactant solution is sprayed on the surface of the natural plant sample, the solid-liquid ratio of the natural plant sample to water or surfactant solution is 1: (1-3) g / mL, and the concentration of the surfactant solution is 1.0-2.0 mg / mL.

3. The method for extracting volatile aroma components from natural plants as claimed in claim 2, characterized in that: The surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide and Tween 80.

4. The method for extracting volatile aroma components from natural plants according to claim 1, characterized in that: The water bath temperature of the solvent-assisted flavor evaporation device is 20-40° C., and the system vacuum degree of the solvent-assisted flavor evaporation device is 10 -3 ~10 -6 Pa; the extraction time is 2 to 5 hours.

5. The method for extracting volatile aroma components from natural plants according to claim 1, characterized in that: The stirring speed of the sample and the extraction solvent in the distillation container is 400~1000r / min, and the addition speed of the extraction solvent is 50~100 drops / min.

6. The method for extracting volatile aroma components from natural plants according to claim 1, characterized in that: The solid-liquid ratio of the natural plant sample to the extraction solvent is 1: (5-20) g / mL.

7. The method for extracting volatile aroma components from natural plants according to claim 1, characterized in that: The natural plant is selected from one of tobacco leaves, tea leaves, osmanthus, hops, tangerine peel, prickly ash, roxburghii and rapeseed; the extraction solvent is an aqueous solution of phenethyl acetate or a dichloromethane solution of phenethyl acetate, wherein the concentration of phenethyl acetate in the extraction solvent is (0.9-1.1) μg / mL.

8. A method for analyzing volatile aroma components in natural plants, characterized in that: The following steps are involved: After the extraction is completed by the method for extracting volatile aroma components from natural plants according to any one of claims 1 to 7, the extract in the collection container of the solvent-assisted flavor evaporation device is made into a test liquid, and the volatile aroma components in the test liquid are tested and analyzed.

9. The method for analyzing volatile aroma components in natural plants according to claim 8, characterized in that: The test analysis is GC-MS analysis, and the chromatographic column used in the GC-MS analysis is a DB-5MS chromatographic column.

10. The method for analyzing volatile aroma components in natural plants according to claim 9, characterized in that: The chromatographic conditions during the GC-MS analysis are: the injection port temperature is 260~270°C; the temperature rise program is from 50~60°C to 250~260°C at 2~3°C / min; the sample is injected in a splitless manner at 260~270°C, and the injection volume is 1~2 μL; the mass spectrometry conditions during the GC-MS analysis are: the ion source temperature is 230~240°C, the transmission line temperature is 270~280°C; the ionization voltage is 70~80 eV, and the scanning range is 33~455 amu.

Images