JPH0568804A - Extractive separation - Google Patents

Abstract

PURPOSE:To prevent an extract from being discharged from a separation tank, accompanied with solvent gas. CONSTITUTION:In extractive separation by fluid in the subcritical or supercritical state, when pressure in a separation tank 7 is decreased, solvent gas is separated from an extract to discharge it through a gas separation membrane 9, causing low boiling components, such as aroma ones accompanied with solvent gas to be effectively captured. Thus, in the production of perfume, an essence of high quality and high potency is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extraction / separation method using a subcritical or supercritical fluid, and more particularly to an extraction / separation method having a high efficiency of obtaining low boiling point components such as aroma components.

[0002]

2. Description of the Related Art Concentration and utilization of aroma components of natural products have been widely practiced for some time. Steam distillation, vacuum distillation, and solvent extraction have been widely used as methods for obtaining aroma components, but these methods cannot avoid the loss of aroma components due to the presence of a heating step. In particular, many natural fragrance components are susceptible to deterioration due to temperature and humidity.
It was often seen that it was lost in the extraction and purification process. In particular, it is difficult to collect the natural scent called low-boiling point components called top notes, and the extracts obtained were often inferior in light fragrance to the natural scent of natural products.

Therefore, it has been proposed to extract and separate the target aroma component using a subcritical or supercritical fluid that does not require the use of heating means.

A fluid in the supercritical state is a fluid in a state in which the critical temperature and the critical pressure are exceeded, and in the case of carbon dioxide, it is 3
1 ° C or higher, 75.3 kg / cm ² or higher, 9 for propane
6.7 ° C or higher, 43.4 kg / cm ² or higher, and ethylene: 9.9 ° C or higher, 52.2 kg / cm ² or higher. These fluids have a density and gas close to those of liquids. It is characterized by having a large diffusion constant close to it, and even fluids in the subcritical state under pressure and temperature conditions that do not exceed the critical point near the critical point are used for extraction and separation of various organic substances together with the fluid in the supercritical state. Has been. In particular, carbon dioxide is harmless as it is used as a food additive in beverages, there is no fear of combustion explosion in the extraction process, and since the critical temperature and critical pressure are relatively low, the temperature and pressure can be changed. By doing so, it is possible to easily change the dissolution characteristics, and it is an extractant suitable for food and medicine. In the case of carbon dioxide,
The fluid in the subcritical state has a temperature of 25 ° C or higher and a pressure of 50 kg.
/ Cm ² or more.

[0005]

FIG. 4 is a diagram for explaining an extraction method using a fluid in a supercritical state. It is introduced into a high pressure pump 2 from a storage tank 1 composed of a cylinder of solvent gas such as carbon dioxide. Then, the fluid in the supercritical state obtained by heating it to the critical temperature or higher in the heat exchanger 3 after being pressurized to the critical pressure or higher is introduced into the extraction tank 4 filled with the material to be extracted, and the predetermined extraction is completed. The supercritical fluid containing the extracted product is decompressed by the decompression valve 5 to a predetermined temperature in the heat exchanger 6, and then separated into the extract and the solvent gas in the separation layer 7. Extract is the outlet 8 of the separation tank
Or the solvent gas is released into the atmosphere as it is,
After being purified in the solvent gas purification apparatus 10 via the back pressure valve 11, it is sent to the solvent storage tank and used again for extraction.

Many methods for extracting aroma components using a fluid in a supercritical state have already been proposed. For example, JP-A-5
Japanese Patent No. 1-333185 describes a method for obtaining coffee oil containing an aroma component by using roasted coffee with carbon dioxide in a supercritical state. Also, JP-A-45-8624
The publication describes a method of extracting volatile aroma components from coffee, tea, etc. using a solvent in a supercritical state. None of the methods described in these publications describes how to prevent the extracted volatile aroma component from being dissipated from the separation tank.

On the other hand, Japanese Laid-Open Patent Publication No. 61-225139,
Japanese Patent Laid-Open No. 63-141559 describes a method in which a substance for inclusion of an aroma component is put in a separation tank in advance and the aroma component extracted with a fluid in a supercritical state is collected. However, in any of the products obtained by these methods, the extract contained something other than the natural product as the raw material, and the extract could not be directly used as a flavor.

Further, Japanese Patent Laid-Open No. 63-310601 describes a method in which the extract is cooled with carbon dioxide as a solvent gas and mixed with dry ice. In this method, the aroma component is prevented from being dissipated from the separation tank by cooling the extract, but when such a method is used for extracting the aroma component, the aroma component is obtained by mixing with dry ice. Since the fragrance component is used, it is difficult to blend as it is, and it is not suitable as an industrial production method. Finally, a device for separating dry ice is required. Further, since the carbon dioxide used for extraction is taken out of the system as dry ice, the carbon dioxide cannot be purified, cooled again and pressurized to be used as a solvent, which also causes an increase in extraction treatment cost.

The present invention prevents the fragrance component, especially the top note which is a low boiling point component, from dissipating when separating the extract containing the fragrance component extracted with the fluid in the supercritical state in the separation tank. It is intended to obtain an extract having a high aroma with a strong aroma, which is closer to that of a natural product.

[0010]

Means for Solving the Problems As a result of intensive investigations by the present inventors in order to collect the fragrance components that are likely to escape, the pressure of the fluid containing the extract in a subcritical or supercritical state is lowered. In the separation tank that separates the solvent gas by
It has been found that by providing a gas separation membrane that selectively permeates only the solvent gas in the solvent gas passage, it is possible to prevent the aroma component from escaping along with the solvent gas from the separation tank.

By such a method, it is possible to prevent a so-called top note, which is a so-called top note, and which has a low boiling point fragrance component, which is easily dissipated, from escaping from the separation tank and concentrates the fragrance component. You can get an extract containing the top notes, coffee,
It is suitable for extraction of various substances having volatile aroma components such as flowers, tea, cacao, black tea, bonito flakes, spices, and flavors.

Referring to the drawings, the present invention will be described with reference to FIG.
FIG. 3 is a diagram for explaining the extraction and separation method of the present invention, in which a solvent gas such as carbon dioxide is introduced from a carbon dioxide storage tank 1 such as a cylinder into a high-pressure pump 2 and pressurized above a critical pressure, and then a heat exchanger 3 At above, the fluid is heated to above the critical temperature to obtain a supercritical fluid. As the extraction solvent, subcritical or liquefied carbon dioxide can be used in addition to the supercritical fluid.

Carbon dioxide has a critical temperature of 31.6 ° C. and a critical pressure of 75.3 kg / cm ² , but in addition to carbon dioxide, ethylene (critical temperature 9.9 ° C., critical pressure 52.2 kg / cm ²
cm ² ), propane (critical temperature 96.7 ° C., critical pressure 4
Many gases such as 3.4 kg / cm ² ) can be used as the solvent gas. In general, carbon dioxide, which is a nonflammable gas having a relatively low critical temperature, harmless to the human body, is preferable.

In the extraction, the subcritical or supercritical fluid is introduced into the extraction tank 4 filled with the extraction raw material, the subcritical or supercritical fluid containing the extract is decompressed by the pressure reducing valve 5, and further, if necessary. Accordingly, when it is introduced into the separation tank 7 through the heat exchanger 6 at a predetermined temperature, the extract and the solvent gas are separated.

In the separation tank, it is necessary that the temperature and pressure are such that carbon dioxide can exist in a gas state. However, since the extract is an aroma component and is deteriorated at a high temperature, the temperature is as low as possible. It is desirable to separate under the conditions.

The extract is obtained from the extract take-out port 8 of the separation tank, and the solvent gas from which the extract has been separated is introduced into a gas separation device 9 having a gas separation membrane which selectively permeates only the solvent gas. As the gas separation membrane, it is possible to use a separation membrane such as a polyimide-based gas separation membrane, cellulose acetate, or cellulose triacetate membrane, but it is preferable that the pore size has fine pores of several angstroms, and the permeation rate of carbon dioxide. A polyimide-based gas separation membrane having a large gas flow rate and a low organic substance permeation rate is particularly preferable.

The separated solvent gas is introduced into the solvent gas storage tank 1 after removing water and the like contained in the solvent gas purifying apparatus 10 having an adsorbing device for activated carbon or the like, and used again for extraction.

As described above, the extraction conditions of the present invention are subcritical or supercritical, but the temperature is 25 to 100 ° C.
The pressure is preferably in the range of 50 to 500 kg / cm ² . However, many aroma components are easily altered by heat, and it is desirable to carry out each step such as extraction and separation at the lowest temperature possible, and the optimum extraction conditions are determined by the type and shape of each natural product as an extraction raw material. It is also possible to add substances such as water or alcohol as an entrainer when performing extraction, or to add organic substances such as water or alcohol to the raw material in advance to accelerate the extraction rate or extract specific components. You can also make it easier.

The extract containing the aroma component extracted with the solvent gas is separated into the solvent gas and the extract in the separation tank. Separation conditions are not particularly limited as long as the temperature and pressure at which carbon dioxide as a solvent becomes a gas state, but preferably 0 to 50 ° C,
It is desirable to carry out in the range of 0 to 60 kg / cm ² .

The extract containing the aroma component collected in the separation tank is accumulated in the lower portion of the separation tank, but the aroma component has a vapor pressure corresponding to the separation temperature in the separation tank and is separated together with carbon dioxide. Trying to escape from the tank. In addition, the extract surface is constantly washed with carbon dioxide flowing from the extraction tank, and a component with a small molecular weight and a low boiling point tends to escape along with carbon dioxide and escape to the outside of the separation tank. By providing the separation membrane, it is possible to prevent dissipation of the aroma component.

[0021]

According to the present invention, when the solvent gas from which the extract has been separated in the separation tank is taken out from the separation tank, a gas separation membrane that selectively permeates the solvent gas is provided in the flow path of the solvent gas. Prevents extracts such as components from being dissipated along with the solvent gas.

[0022]

EXAMPLES The present invention will be described in more detail below by showing Examples of the present invention.

Example 1 As shown in FIG. 2, an extraction tank 24 having an internal volume of 690 ml was filled with 230 g of roasted coffee grounds. In the extraction tank, carbon dioxide in a supercritical state at a temperature of 40 ° C. and a pressure of 350 kg / cm ² obtained by pressurizing carbon dioxide from a carbon dioxide cylinder 21 with a high-pressure pump 22 and heating with a heat exchanger 23 for 3 hours. It is supplied and decompressed by the decompression valve 25, and the temperature is 9 ° C and the pressure is 9 kg / cm in the separation tank 26.
Separation was performed under the condition of ² .

A gas separator 28 was provided in the carbon dioxide gas flow path of the separation tank. An air dryer UM-A5 manufactured by Ube Industries, Ltd. having a polyimide-based gas separation membrane was used as the gas separation device membrane. This gas separation membrane is 6 × 10 ^-5 cc / cm ² · sec · cmHg for carbon dioxide.
It had a gas permeability coefficient of.

The extract obtained from the separation tank was 5.2 g. In addition, coffee odor was hardly recognized in the carbon dioxide discharged through the gas separation membrane, and it had a strong sour odor.

The goodness and strength of the coffee flavor of the extract obtained from the extract outlet 27 of the separation layer were evaluated by sensory evaluation and headspace gas chromatography (HSGC).
Evaluated by analysis.

Further, the gas that has permeated the gas separation membrane is -3
Pass the collector 30 containing 0 ° C. ethanol,
The coffee flavor component that passed through the gas separation membrane together with carbon dioxide was collected in ethanol. Exhaust gas from the collector was discharged into the atmosphere through the exhaust port 31. The strength of coffee odor of the obtained ethanol collection liquid was evaluated by sensory evaluation and gas chromatography (GC).

Sensory evaluation of the extract was performed by 10 well-trained sensory panelists. An amount of the extract corresponding to 1 g of the ground coffee grounds was dissolved in 1 g of a 1% sugar ester ethanol solution, which was added to 200 g of pure water to evaluate the quality and strength of the flavor. Evaluation was carried out by a 7-point method, and the highest score was 7 and the lowest was 1, and the evaluation was made by the average score of all inspectors.

In the HSGC analysis of the extract, the total peak area value obtained by the analysis under the same conditions was determined as a guideline for the aroma intensity. HSGC is a so-called top flavor that is highly volatile among aroma components, in which the aroma components floating in the space of the sample bottle are analyzed by gas chromatography. It is effective for (top note) analysis and has a close relationship with the intensity of coffee aroma.

The sensory evaluation of the ethanol-collecting liquid was carried out in the same manner as the sensory evaluation of the extract except that the ethanol-collecting liquid was diluted with pure water by a factor of two. G of ethanol collection liquid
In the C analysis, the area values of all peaks except the ethanol peak among the peaks obtained by the analysis under the same conditions were obtained.

As shown in Table 1 for the sensory evaluation and the GC analysis results, the flavor of the extract is highly evaluated and the GC analysis value is high when the gas separation membrane is provided as compared with the case where it is not provided. There was a strong flavor. On the other hand, the coffee aroma component in the exhaust gas from the exhaust valve 29 was very small when the gas separation membrane was provided.

Comparative Example 1 As shown in FIG. 3, the same as Example 1 except that a back pressure valve 32 was provided in the gas flow path from the separation tank without providing a gas separation membrane to perform extraction separation. Extraction separation was performed under the conditions, and 5.1 g of an extract was obtained from the separation tank. The solvent gas discharged from the exhaust valve 29 during the extraction had a strong coffee odor. The extract thus obtained and the ethanol collection liquid obtained by treating in the same manner as in Example 1 were subjected to sensory evaluation, HSGC analysis and GC analysis in the same manner as in Example 1.

The results are shown in Table 1.

[0034]

[Table 1]

[0035]

EFFECT OF THE INVENTION In a method of extracting and separating with a fluid in a subcritical or supercritical state, the solvent gas separated from the extract by lowering the pressure in a separation tank is discharged through a gas separation membrane to form a solvent gas. It is possible to collect a low boiling point component such as an accompanying aroma component which is difficult to be collected, and in particular, in the production of a fragrance, a high-quality and high-potency extract can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an extraction / separation method of the present invention.

FIG. 2 is a diagram illustrating an extraction method using a fluid in a supercritical state described in Examples.

FIG. 3 is a diagram illustrating an extraction method using a fluid in a supercritical state described in a comparative example.

FIG. 4 is a diagram illustrating a conventional extraction method using a fluid in a supercritical state.

[Explanation of symbols]

1 ... Storage tank, 2 ... High pressure pump, 3 ... Heat exchanger, 4 ... Extraction tank, 5 ... Pressure reducing valve, 6 ... Heat exchanger, 7 ... Separation tank, 8 ... Extract outlet, 9 ... Gas separation device, 10 ... Solvent gas purifier, 11 ... Back pressure valve, 21 ... Carbon dioxide cylinder, 22 ...
High-pressure pump, 23 ... Heat exchanger, 24 ... Extraction tank, 25 ... Pressure reducing valve, 26 ... Separation tank, 27 ... Outlet port, 28 ... Gas separation device, 29 ... Exhaust valve, 30 ... Collection device, 31 ... Exhaust port , 32 ... Back pressure valve

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Kayoko Mishima 706-1 Shinbo, Okayama City, Okayama Prefecture (72) Inventor Shigeru Yamamoto 972-7-3 Hongo Town, Omiya City, Saitama Prefecture (72) Inventor Ritsuko Ishino Port of Tokyo 3-3-7-924, Kita-Aoyama, Ward

Claims (4)

[Claims] 1. A method of extraction and separation using a subcritical or supercritical fluid, wherein a solvent gas, which has been decompressed in a separation tank to separate the extract, is passed through a gas separation membrane which selectively permeates the solvent gas. Extraction and separation method characterized by discharging. 2. The extraction and separation method according to claim 1, wherein the gas separation membrane is a polyimide-based gas separation membrane. 3. The extraction and separation method according to claim 1, wherein the extract is a substance containing an aroma component. 4. The extract according to claim 3, which is a substance containing a volatile aroma component of coffee or tea.
The described extraction and separation method.