CN104862079B - A kind of method for extracting faenum graecum blade essential oil - Google Patents

Abstract

The invention discloses a method for extracting the essential oil of fenugreek leaves, which comprises firstly kneading the leaves of fenugreek until the juice just comes out, drying naturally, crushing and sieving to obtain fenugreek leaf powder; Mix water and ethanol at a mass ratio of 1:85g/ml to make a mixture; put the mixture in a 55°C water bath for 21 hours; then centrifuge at a speed of 5000r/min for 30min, collect the supernatant, and put it into a test tube; finally put The test tube was placed in a water bath at 85°C and heated for 4.2 hours. After the ethanol was completely evaporated, the remaining part was the final extraction product - fenugreek essential oil. The method for extracting the essential oil of fenugreek leaves provided by the invention is separated and extracted by water bath, centrifugation and heating, the material is easy to obtain, the treatment is simple, the extraction efficiency is high, and the residual organic solvent content in the extracted essential oil is small, the method is simple, and the operation is simple. Convenience.

Description

A method for extracting fenugreek leaf essential oil

technical field

The invention belongs to the technical fields of medicine, food and chemical industry, and in particular relates to a method for extracting fenugreek leaf essential oil.

Background technique

Fenugreek is the seed of Trigonella foenun-graecu L., a leguminous plant. Fenugreek is also known as rue grass ("Shengjing Tongzhi"), vanilla, bitter grass, bitter flower, sweet alfalfa, etc. It is an annual leguminous plant. Herbaceous plant, the whole plant has aroma, the whole plant is harvested when the fruit is ripe, the seeds are planted, dried in the sun, can be used raw or slightly fried, it is a commonly used traditional Chinese medicine. It is mainly produced in my country's Tibet, Anhui, Sichuan, Ningxia, Gansu and other provinces. It mainly has the effects of warming the kidney and strengthening yang, dispelling cold and dehumidification, treating cold hernia, cold-damp beriberi, kidney deficiency, backache, and impotence. It is a famous Chinese medicine ingredient. Therefore, it is necessary to study the ingredients and extraction methods of fenugreek. The main active ingredient of fenugreek is volatile oil, which is also called essential oil. The components of volatile oil are relatively complex, mostly composed of dozens or even hundreds of compounds, generally Terpenoids, aromatic compounds, aliphatic compounds, nitrogen-sulfur compounds, etc. are the main components, but there are often certain components that account for a large amount, and have important uses in medicine, food and chemical industries. Pure natural plant essential oils have the following functions: fragrant smell, after the natural aroma enters the brain through the olfactory nerve, it can stimulate the front lobe of the brain to secrete two hormones, endorphin and enkephalin, and make the spirit in the most comfortable state. This is the best way to protect the soul. Moreover, different essential oils can be combined with each other to create a fragrance you like, which will not destroy the characteristics of the essential oils, but will make the essential oils more powerful. The essence of essential oils can prevent infectious diseases, fight bacteria, viruses, molds, prevent inflammation, prevent spasms, promote cell metabolism and cell regeneration, and make life better. Some essential oils can regulate endocrine organs, promote hormone secretion, and allow the body's physiological and psychological activities to develop well. At present, 95% of the aromatic plant essential oils are extracted by distillation, but when the hot steam is filled in the container, the aromatic essential oil components in the plant will evaporate along with the water vapor. Solvent extraction method, this extraction method is relatively expensive because of its complicated process. The traditional solvent extraction method extracts flowers, petals, flower buds and other parts of plants. The product after the first extraction is called "Concrete". If the natural secretions of plants are extracted, such as gums, resins or tree pastes, the first product is called "resinoid". After the first product "resin" or "cream" is extracted again with alcohol or alcohols, the final product of the second stage is called absolute oil (Absolute). Finally, the oil in the balm is washed away with volatile pure alcohol to obtain exquisite and expensive absolute oil, and the yield of extracted essential oil is relatively small.

At present, most of the active ingredients of fenugreek are extracted from its seeds with ether. The extraction of its active ingredients, namely essential oil, from the stems and leaves of fenugreek has been studied, but it is limited to extraction with ether, which has poor extraction effect and causes great environmental pollution. , can not be fully used in industrial production.

Contents of the invention

The purpose of the present invention is to provide a method for extracting the essential oil of leaves of fenugreek, aiming at solving the problems that the effective components of fenugreek are extracted with ether, the extraction effect is poor, and the environmental pollution is large.

The present invention is achieved in this way, a method for extracting the essential oil of Fenugreek leaves, the method for extracting the essential oils of Fenugreek leaves comprises the following steps:

First, knead the leaves of fenugreek by hand until the sap just comes out, so that the cells are broken, and the oxidative enzymes can further react with the organic substances to produce more essential oils. Dry naturally, let the water evaporate completely, crush and sieve to obtain fenugreek leaf powder, the purpose is to make the leaves smaller and fully contact with ethanol;

Next, mix the leaf powder and absolute ethanol according to the mass ratio of 1:85g/ml and put it into a conical flask, stir fully with a glass rod to completely immerse the leaf powder in absolute ethanol, let the leaf powder and ethanol fully contact to make a mixture, and seal the triangular flask. bottle to prevent ethanol from volatilizing;

Put the mixture again in a water bath at 55°C for 21 hours, let the organic substances in the plant cells be completely released at a certain temperature, and dissolve into ethanol; then centrifuge at a speed of 5000r/min for 30min to remove impurities and collect the supernatant , into the test tube;

Finally, put the test tube into an 85°C water bath and heat it for 4.2 hours to let the ethanol evaporate rapidly at a certain temperature. At the same time, use chromium sulfate to detect the ethanol content. of fenugreek essential oil.

The invention provides a method for extracting the essential oil of fenugreek leaves. By crushing the cells, the combination of organic matter and enzymes is accelerated, so that the yield of the essential oil is greatly increased; the cells are further broken by heating, that is, in a water bath, so that the essential oil is fully dissolved in ethanol, centrifuged to separate impurities, and further purify the essential oil. Heating and separating ethanol makes the ethanol volatilize quickly and improves the purity of the essential oil. The advantages of this method are that the material is easy to get, the processing is simple, the extraction efficiency is high, the essential oil content reaches 14%, and the residual organic solvent content in the extracted essential oil is small. The content is only 0.036%, the ethanol can be fully recovered and reused, the method is simple, and the operation is convenient.

Description of drawings

Fig. 1 is the flow chart of the method for extracting fenugreek leaf essential oil provided by the embodiment of the present invention;

Fig. 2 is the peak schematic diagram of the methanol extract provided by the embodiment of the present invention;

Fig. 3 is a schematic diagram of the peak of the absolute ethanol extract provided by the embodiment of the present invention;

Fig. 4 is the peak schematic diagram of the water extract provided by the embodiment of the present invention;

Figure 5 is a schematic diagram of superimposed peaks of three solvent extracts provided by the embodiments of the present invention;

In the figure: ("─" means methanol extract "---" means absolute ethanol extract "..." means water extract);

Fig. 6 is a schematic diagram of the influence of the solvent provided by the embodiment of the present invention on the extraction of the active ingredients of fenugreek;

Fig. 7 is a schematic diagram of the influence of the material ratio provided by the embodiment of the present invention on the extraction of active ingredients of fenugreek;

Fig. 8 is a schematic diagram of the influence of temperature on the extraction of active ingredients of fenugreek provided by the embodiment of the present invention;

Fig. 9 is a schematic diagram of the influence of time provided by the embodiment of the present invention on the extraction of active ingredients of fenugreek;

Fig. 10 is a schematic diagram of the influence of different rotating speeds on the purity of the essential oil of fenugreek leaves provided by the embodiment of the present invention;

Fig. 11 is a schematic diagram comparing the amount of essential oil in treated and untreated fenugreek leaves provided by the embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The present invention utilizes fenugreek leaves, applies absolute ethanol, separates and extracts through water bath, centrifugation and heating, the material is easy to obtain, the treatment is simple, the extraction efficiency is high, and the residual organic solvent content in the extracted essential oil is small, and the steps are simple. Easy to operate.

Below in conjunction with accompanying drawing 1, extraction method of the present invention is described in detail:

S101: firstly knead the leaves of fenugreek until the juice just comes out, dry naturally, crush and sieve to obtain fenugreek leaf powder;

S102: Next, mix the leaf powder and absolute ethanol into a conical flask according to the mass ratio of 1:85g/ml, stir fully with a glass rod to completely immerse the leaf powder into absolute ethanol to form a mixture, and seal the conical flask;

S103: Place the triangular flask containing the mixture in a 55°C water bath for 21 hours; then transfer it to a 50ml centrifuge tube, centrifuge at a speed of 5000r/min for 30min, collect the supernatant, and put it into a test tube;

S104: Finally, heat the test tube in a water bath at 85°C for 4.2 hours, and measure the ethanol content in the mixture at the same time. After the ethanol is completely evaporated, take out the test tube, and the remaining part is the final extraction product - fenugreek essential oil.

The application effect of the present invention is described in detail through the following experiments:

1. Experimental materials

The leaves of fenugreek fruit are picked when they are not yet fully mature, some of them are kneaded by hand until the juice just comes out, and then dried naturally, and some of them are left untreated, dried naturally, and collected for later use.

2. Reagents

Reagents: methanol, water ethanol, double distilled water.

3. Experimental method

Weigh 5g of Fenugreek powder, extract active ingredients with methanol, water ethanol, double distilled water. To study the influence of four single factor factors (solvent, material ratio, temperature, time) on the amount of essential oil extracted, one of the factors was used as a variable, and the other three factors were kept unchanged for the experiment. The centrifuge speed, distillation temperature and other indicators were studied.

4 Experimental results

4.1 The influence of different solvents on the amount of essential oil extracted

Choose different solvents (methanol, absolute ethanol, distilled water), according to material ratio 1:50, temperature 40 ℃, time 5h carry out experiment, method is the same as above, utilize UV-2450 ultraviolet-visible spectrophotometer to measure the extraction of three kinds of solvents obtained peak of the liquid. The results are shown in the following 2-Figure 5; from Figure 5, it can be obtained that the maximum peaks of the three solvents simultaneously appeared at the wavelength of 670nm. Therefore, this wavelength was used in the subsequent single factor factor analysis.

4.2 Analysis of influence of single factor on extraction

4.2.1 The effect of solvent on the extraction of active ingredients of fenugreek

The extracts of the above three solvents were diluted 50 times at the same time, and the light absorption value was measured at a wavelength of 670nm. The results are shown in Figure 6, and it can be seen from Figure 6 that the light absorption value of the methanol extract is the largest, indicating that methanol is the best solvent for extracting the active ingredients of Fenugreek, but methanol is toxic and will pollute the environment, and methanol The difference between the amount of extraction and ethanol is small, so the best extraction solvent is ethanol.

4.2.2 The effect of material ratio on the extraction of active ingredients of fenugreek

Solvent: ethanol, temperature: 40°C, time: 5h, material ratio gradient is 1:40～～～1:100, every 5 units is a gradient, 13 concentration gradients are set, the extraction method is the same as above, the result is shown in Figure 7 It can be seen from Figure 7 that the light absorption value is the largest when the material ratio is 1:85, indicating that 1:85 is the best material ratio for the extraction of active ingredients of fenugreek.

4.2.3 The effect of temperature on the extraction of active ingredients of fenugreek

Solvent: ethanol, material ratio: 1:85, time: 5h, the extraction method is the same as above, and the result is shown in Figure 8. It can be seen from Figure 8 that the light absorption value is the largest at a temperature of 55°C, indicating that 55°C is the effective time for fenugreek. Optimal temperature value for component extraction.

4.2.4 The effect of time on the extraction of active ingredients of fenugreek

Solvent: ethanol, material ratio: 1:85, temperature: 55°C, the extraction method is the same as above, and the results are shown in Figure 9:

It can be seen from Figure 9 that the light absorption value is the largest at 21 hours, indicating that 21 hours is the best time to extract the active ingredients of fenugreek.

4.3 Effects of different centrifugal speeds on the purity of fenugreek leaves essential oil

Get five groups of filtrates and centrifuge at 3000r/min, 4000r/min, 5000r/min, 6000r/min, and centrifuge at 7000r/min for 30 minutes, as shown in Figure 10, different centrifugal speeds have a greater impact on the extraction of fenugreek leaf essential oil Large; when the speed is between 3000r/min and 5000r/min, the amount of essential oil decreases significantly with the increase of the speed, and the centrifugal speed increases, the better the effect of removing impurities, the amount of essential oil tends to be stable when the speed is greater than 5000r/min The higher the speed, the greater the damage to the machine. Based on the above factors, the best centrifugal speed should be 5000r/min.

4.4 Effect of distillation temperature on the amount of essential oil in fenugreek leaves

Take five groups of filtrates and use a centrifuge to centrifuge them for 30 minutes at 5000r/min, distill and extract the centrifuged liquids in water baths at 70°C, 75°C, 80°C, 85°C, and 90°C respectively, and record the remaining Indexes such as the volume of ethanol, solution viscosity and the color change of solution and the time used for final ethanol volatilization; Results are as shown in table 1:

Table 1: Determination of the optimum temperature for extraction of essential oil from fenugreek leaves

It can be seen from Table 1 that when the extraction temperature is 70°C, 75°C, and 80°C, although the final extracted essential oil has good color and quality, the time used is too long, which is not conducive to the extraction of essential oil; when the extraction temperature is 85°C, the extracted essential oil The color is good, the quality is good, and the time used is short; at 90°C, although the time is short, the essential oil has poor color and quality, so 85°C is selected as the suitable temperature.

4.5 Extraction rate of essential oil in treated and untreated fenugreek leaves

Take five groups of filtrates of 1g of treated leaves and untreated stems and leaves, centrifuge at 5000r/min for 30min, take the centrifuged liquid and extract essential oil in a water bath at 85°C, weigh the amount of essential oil after obtaining the oil, and calculate according to the extraction rate of essential oil = The amount of oil/weight of fenugreek powder × 100%, the calculated extraction rate of essential oil from treated leaves of fenugreek was 14.4%, and the extraction rate of essential oil from untreated leaves of fenugreek was 10.7%. The results are shown in Figure 11:

In summary, the present invention adopts ethanol extraction and water-bath distillation to extract the essential oil in the leaves of fenugreek, adopts the extraction process of ethanol extraction, the yield of essential oil in the leaves of fenugreek is high, the whole experimental process time is shorter, and the temperature of the whole process is relatively high. Low, thus ensuring that the essential oil components will not be damaged by extraction.

Through the present invention, it is found that when the centrifugal speed is 5000r/min, the extraction temperature is 85°C and the material ratio (fenugreek leaf: absolute ethanol) obtained in the previous test is 1:85, the water bath extraction temperature is 55°C, and the water bath time is 21h , the extraction of essential oils from fenugreek leaves is the best. And it was found that the amount of essential oil in treated fenugreek leaves was slightly higher than that in untreated fenugreek leaves.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (4)

1. a kind of method for extracting faenum graecum blade essential oil, it is characterised in that the method bag of the extraction faenum graecum blade essential oil Include following steps：

The blade of faenum graecum is rubbed with hand to juice is just gone out first, dries naturally, grinding and sieving, obtains faenum graecum leaf powder；

Secondly leaf powder and absolute ethyl alcohol are pressed 1:85g/ml mixing is fitted into triangular flask, is sufficiently stirred for making leaf powder complete with glass bar Absolute ethyl alcohol is immersed, mixture is made, triangular flask is sealed；

The triangular flask that will be equipped with mixture again is put into water-bath 21h in 55 DEG C of water-baths；Then it is transferred in 50ml centrifuge tubes, is turning Speed collects supernatant to centrifuge 30min under 5000r/min, loads test tube；

Finally test tube is put into 85 DEG C of water-baths and heats 4.2h, while detecting ethanol content in mixed liquor, treats that ethanol is waved completely Hair falls, and takes out test tube, remainder is extraction end-product-faenum graecum blade essential oil.

2. application of the faenum graecum blade essential oil in pharmacy described in a kind of usage right requirement 1.

3. application of the faenum graecum blade essential oil in food described in a kind of usage right requirement 1.

4. application of the faenum graecum blade essential oil in chemical industry described in a kind of usage right requirement 1.