JPS645874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is free of polyphenols, resins and waxes and has a reduced nicotine content by 5 to 50% (relative to the tobacco from which the tobacco aroma oil is obtained). and relates to a novel product which is a clear tobacco aroma oil having a tobacco aroma characteristic of the raw tobacco used.
Furthermore, the present invention relates to a method for separating transparent tobacco aroma oil from tobacco extracts and its use.

When manufacturing tobacco products, imparting aroma to tobacco plays an important role.
Some or all of the tobacco aroma oil unique to a specific tobacco is extracted from highly aromatic tobacco or tobacco waste.
Attempts to isolate it for addition to other less aromatic tobaccos from the same source have previously been unsuccessful. This is because it has proven impossible to isolate anhydrous (clear) tobacco aroma oil that is free of resins and waxes and has a reduced nicotine content.

German Patent Application No. 2128779 states:
Tobacco is extracted with one or more solvents located between trichlorethylene and ethyl acetate in the eluotropic series and aromatic precursors are extracted from the resulting extract by heat treatment at 110 to 180°C. A method for isolating aroma substances from tobacco and converting aroma precursors is described, which is characterized in that the aroma substances are activated. The aroma product obtained by this method is a wax-like resinous material and contains all the waxes and resins of the starting product as well as the polyphenols and almost all the nicotine.

In German Patent Application No. 2142205,
In a method for selectively extracting nicotine from tobacco while preserving its aroma, the first step is to extract dry gas (e.g.
The aroma is removed by treatment with CO ₂ ) and then placed in a separation vessel B until the nicotine precipitated in vessel D is extracted from the tobacco in vessel A in a second stage using moist CO ₂ . A method is described which is characterized in that it is temporarily stored. In the third stage, the aroma substances present in container B are dissolved, for example by CO ₂ above the critical point,
It is returned to container A, where it is deposited on the tobacco.

The above methods are expensive and inefficient in obtaining and utilizing tobacco aroma. This is because the product obtained in the first stage is not a clear liquid tobacco aroma oil that can be separated from the resins and waxes, but almost all of the undesirable waxes and resins of the starting product as well as the undesirable This is because it is a paste-like material containing polyphenols. Moreover, these waxy and resinous substances prevent uniform distribution and aroma transfer in the re-aromatization of the tobacco to be treated. Polyphenols have the disadvantage, among other things, of impairing the aroma of smoke.

In German Patent Application No. 2844781,
For example CO ₂ 93 mol% + ethanol 7 mol% or
A method is described for the extraction treatment of vegetable and animal substances, in particular for the processing of tobacco, by using a binary solvent such as 94 mol % CO ₂ + 6 mol % butane. The purpose of this two-phase mixture is, for example, to avoid adducts formed in organic solvent extraction and changes in the treated material. When operating under supracritical pressure conditions using only CO ₂ , pressures of 150 bar or more are required to achieve adequate extraction.
With the method according to German Patent Application No. 28 44 781, the above-mentioned disadvantages can be avoided by adding, for example, a certain amount of alcoholic solvent as a covalent agent for the CO ₂ used for the extraction. .

This method, similar to the method according to DE 21 42 205, produces a paste containing only a small amount of aromatic substances, but all the wax and resin fractions of the tobacco used for extraction as well as undesired polyphenols. Only substances are produced as intermediate products.

None of the known methods makes it possible to obtain tobacco extracts or tobacco aromas that have a tobacco aroma characteristic of the particular raw tobacco used.

One object of the present invention is that the starting product qualitatively and quantitatively contains almost all the aroma substances, is free of resins, waxes and polyphenols, and that its nicotine content is - The object of the present invention is to obtain a clear and anhydrous tobacco aroma oil which is significantly reduced compared to the present invention.

This object is solved by the method defined in the claims.

Known methods for extracting tobacco with organic solvents or for extracting tobacco with gases above the critical point, such as e.g. CO ₂ , always remove almost all resins and waxes of the raw material and By primary extraction with organic solvents or mixtures of these solvents with each other or with carbon dioxide and a subsequent secondary extraction with CO ₂ to produce only pasty aromatic products containing polyphenols. It is surprising that a two-phase resin/fragrance oil mixture is produced which can be easily separated into a clear tobacco aroma oil and a solid resin/wax mixture free of aromatic compounds.

The invention will be explained in more detail below.

In the present invention, tobacco refers to fermented tobacco leaves, petioles, stems, powder, and tobacco waste.

Tobacco primary extract within the meaning of the present invention is:
Common organic solvents, especially benzene, toluene, methanol, ethanol, n-propanol, methylethyl acetate, diethyl ether, acetone, n-
Extracts prepared using propane, n-hexane, cyclohexane, petroleum ether, dichloromethane or trichloromethane or mixtures of these solvents. A primary extract in the sense of the present invention is also a CO ₂ extract, ie an extract prepared using CO ₂ as a solvent.

Adsorbents in the sense of the present invention include all customary adsorbents, in particular activated carbon, alumina, magnesium oxide, sodium aluminum silicate, bleaching earth,
bentonite, silica gel, diatomaceous earth, zeolitic molecular sieves and the like.

Tobacco aromatic oil in the sense of the present invention is very transparent at room temperature and free of resins and waxes as well as polyphenols and from which the tobacco extract contains up to 5 to 50% of the tobacco from which it is derived (in particular (up to 10 to 40%)
It has a reduced nicotine content and does not form turbidity or sediment when 95% strength ethanol (containing 95% by weight ethanol) is added.
It is an oily liquid with a tobacco aroma.

The preparation of the tobacco primary extract used according to the invention is carried out in particular by using tobacco in one of the solvents mentioned above.
It consists in extracting the seeds or (in the case of organic solvents) into a solvent mixture.

Preferably one of the abovementioned solvents (preferably _CO2 , n-hexane or dichloromethane)
Tobacco pre-milled using 3 to 30 parts by weight 1
Parts by weight are extracted. Depending on the efficiency of existing extraction equipment, the primary extraction is carried out for at least 10 minutes and at most 10 hours, preferably from 1 to 5 hours.

If organic solvents are used, the primary extraction is carried out under conditions of atmospheric pressure.

If CO ₂ is used in the primary extraction, the pressure and temperature conditions in the extraction vessel and separation vessel and the extraction time and CO ₂ flow rate are (single stage)
This is equivalent to what will be described later in connection with secondary extraction.

Undissolved residues from the treatment with these solvents are separated and the solvent-containing extract is concentrated by evaporation until a syrupy solvent-free tobacco extract is obtained. If organic solvents are used, the evaporation is preferably carried out under reduced pressure, particularly preferably at about 15 mmHg. If CO ₂ is used, the evaporation takes place in a separation vessel, as already mentioned, under the pressure and temperature conditions described below for the (single-stage) secondary extraction.

The tobacco primary extract obtained in this way is
It contains inter alia polyphenols, resins/waxes and nicotine and, as the inventors have found, is present in an easily obtainable form that is particularly suitable for subsequent secondary extraction (with _CO2 ).

The obtained tobacco primary extract is then thoroughly mixed with the adsorbent until, according to the invention, there is a uniform distribution between the extract and the adsorbent.
Particularly suitable adsorbents for this step are sodium aluminum silicate, bentonite, magnesium oxide and zeolitic molecular sieves. The mixing ratio of extract to adsorbent can be varied and adjusted to suit the consistency of the extract, the density and particle size of the adsorbent and the desired consistency resulting from the mixing. Generally 1:0.1 to 1:10
A suitable extract to adsorbent mixing ratio of 1:
Powdered extracts having an extract to adsorbent mixing ratio of 0.3 to 1:6 are preferred.

The extract/adsorbent mixture should not be in a ratio lower than 1:0.1. This is because the adsorbent used according to the invention is a clear, anhydrous material that can be easily separated from resins and waxes and the dissolution of aromatic substances in the subsequent secondary extraction (in the extraction vessel) with _CO2 . This is because it has a significant effect on the separation of tobacco aroma oil.

Mixing ratios greater than 1:10 still result in better dissolution and separation of tobacco aroma oil, but larger pressure vessel volumes must be accommodated.

According to the invention, the mixture of primary extract and adsorbent is extracted in a first pressure vessel (extraction vessel), preferably a high-pressure vessel, under constant pressure and temperature conditions with CO ₂ to remove all the aromatic in a second pressure vessel (separation vessel) following the extraction vessel until the substance is present as an oily liquid that can be easily separated from the resin and wax.

This secondary extraction with CO ₂ according to the method of the invention brings the CO ₂ used to extract the extract/adsorbent mixture above the critical point in terms of pressure and temperature (>73 bar and >31.3 °C ) or by keeping it below the critical point with respect to pressure and temperature (<73 bar and <31.3°C) or above the critical point with respect to pressure (>73 bar) and below the critical point with respect to temperature (<31.3°C) .

When operating under conditions above the critical point with respect to pressure and temperature, pressures of 85 to 250 bar and temperatures of +35°C to +90°C are preferably chosen. When operating in the subcritical pressure and temperature range, pressures of 25 to 70 bar and temperatures of +5°C to +25°C are preferred. 85 to 200 when operating at pressures above the critical point and temperature ranges below the critical point.
A pressure of bar and a temperature of +10°C to +30°C are preferred.

If a particularly low nicotine content is desired in the final product (secondary extract) (e.g. 5 to 10% with respect to the tobacco used for the primary extraction), an additional CO ₂ extraction step at low temperature can be claimed. can be inserted between the primary extraction specified in and the secondary extraction specified in .

For this purpose, (a) a first extraction stage with CO ₂ at a temperature of -25° C. to +5° C. and a pressure of about 20 to 25 bar in an extraction vessel; and (b) then a pressure and a pressure in said extraction vessel. temperature 25
CO ₂ raised above bar and above 5°C
Preferably, it is carried out in the second extraction stage.

In the first extraction stage with CO ₂ described above, the separation vessel is depressurized under pressure and temperature conditions below the critical point, with the separation (of nicotine) in the separation vessel occurring at approximately +15 °C or Preference is given to carrying out at a temperature of +30° C. and a pressure of about 2 to 15 bar. An extraction time of 0.5 to 2 hours, preferably about 1 hour, and a CO ₂ flow rate of 5 to 50 Kg/hr, preferably 10 to 30 Kg/hr are sufficient for this step. Surprisingly, this intervening CO ₂ extraction step almost exclusively removes nicotine and other secondary alkaloids from the primary extract/adsorbent mixture (but also aromatics, resins, waxes, etc.). Only the other components (excluding polyphenols and other such components which are themselves CO ₂ soluble) are eluted and precipitated in the separation vessel. The obtained nicotine is removed from the separation vessel before the next secondary extraction with _CO2 (aromatic extraction) begins.

In the process according to the invention as defined in the claims, especially in the secondary extraction, the separation conditions in the expansion vessel (separation vessel) are determined by the quality and quality of the product isolated according to the invention. Critical to quantity. The expansion pressure and expansion temperature are
It is advantageously in the range below the critical point of CO ₂ (subcritical pressure/subcritical temperature). 45 to 65
A pressure of about 50 to 55 bar and a temperature of about 20 to 25 bar is preferred.
A temperature of 0.degree. C. is particularly preferred. The separation within the expansion vessel is
Preferably, the pressure and temperature conditions within the extraction vessel are carried out with a simultaneous reduction in pressure and temperature.

The amount of CO ₂ flowing through the extraction vessel and the length of the flow-through treatment are also important for the method according to the invention. A total treatment time of 0.5 to 8 hours, preferably 1 to 5 hours and particularly preferably 2 to 4 hours is advantageous, and 1 kg of untreated tobacco
0.3 to 35 Kg/hour, preferably 3 to 30 Kg/hour and particularly preferably 5 to 15
Kg/hour total CO ₂ flow rate is advantageous.

As already mentioned above, the CO ₂ extraction conditions indicated above for the (one stage) secondary extraction such as pressure and temperature in the extraction vessel, pressure and temperature in the separation vessel, extraction time and CO ₂ flow rate are , is also valid for primary extraction if CO ₂ is used as solvent in the primary extraction. There is therefore no need to specifically enumerate these parameters again in the case of primary extraction.

In the process according to the invention, upon removal from the expansion vessel after the end of the secondary extraction, a solid/oil mixture is obtained which is already present as two phases. By simple filtration, this mixture can be separated into a clear, anhydrous tobacco aroma oil, free of polyphenols and with a significantly reduced nicotine content, and a solid resin/wax mixture with a relatively high nicotine content.

Another special feature of the tobacco aroma oil isolated according to the present invention is that it has a tobacco aroma characteristic of the particular source tobacco used. This property clearly distinguishes it from any existing tobacco extract. This is because it has not been possible to prepare the unique aroma of a specific raw material tobacco using any conventional tobacco extract. Due to this feature of the tobacco extract isolated according to the present invention, its physical composition is considered to be completely novel compared to the known art.

At the same time, aroma substances, polyphenols, nicotine,
Starting from a product containing resins, waxes and other substances (secondary tobacco extract), for the first time the separation and obtainment of tobacco aroma as a clear anhydrous oil can be carried out easily. achieved by any means possible and with particularly effective results. Neither the process itself nor the products obtained have been described or suggested in the prior art.

In the product obtained according to the invention, after the secondary extraction has ended, an easily separable tobacco aroma oil has a significantly reduced nicotine content and is free of polyphenols, resins and waxes. It is remarkable and surprising that a transparent layer of 100% and a resin/wax layer containing most of the primary extract nicotine is removed from the expansion vessel.

The tobacco components isolated by the primary extraction in the process according to the invention are present in a mixture with a powdered adsorbent and in a subsequent secondary extraction (with CO ₂ ).
Regarding their viscosity and solubility and separation properties, e.g. primary extraction of tobacco leaves (CO ₂ primary extraction)
What was surprising was that the same component behaved completely differently than the same component that received it alone.

This fact is very clear in the case of the particularly effective nicotine extraction optionally inserted according to the invention (possibly an intermediate extraction step). Thus, according to previous knowledge, nicotine and polyphenols can only be extracted using _CO2 , for example from tobacco leaves, only in the presence of moisture. However, in the process according to the invention, almost all of the nicotine is eluted from the primary extract prepared according to the invention and placed in a separate vessel, despite not adding or using water in any step. Precipitate. This new finding also indicates that almost pure nicotine (if desired) can be extracted from the primary extract/adsorbent mixture by -
An alternative method according to the invention results in selective extraction by (dry) CO ₂ extraction at temperatures between 25° C. and +5° C.

Even more surprising is the effect of improving the yield and purity of the product prepared according to the invention as well as its flavor.

Until now, little was known about the aromatic oil of tobacco. Aromatic oils isolated by conventional methods have only been prepared on a laboratory scale by steam distillation. The resulting oil was accompanied by a number of external odors, such as chamomile, fenugreek, pepper, valerian and amyl alcohol, probably caused by the formation of the processed product. The yield of this type of tobacco oil was about 0.1 to 0.2%.

As already mentioned, there are distinct differences between these tobacco oils and the tobacco aroma oils which have the pure aroma characteristic of the particular source tobacco isolated and used in accordance with the present invention. Thus, for example, an aromatic oil isolated from Havana tobacco has a Havana tobacco aroma, while an aromatic oil obtained from Kentucky tobacco has a Kentucky tobacco aroma. Similarly, aromatic oils isolated from Virginia, Turkish or Burley tobacco each have a pure aroma characteristic of that particular type of tobacco. Because of this special feature, which clearly differs from the prior art, it can be said that the tobacco aroma oil isolated according to the invention is completely new in its material composition compared to the products according to the prior art. can.

The tobacco aroma oil isolated by the method according to the invention is free of extraneous aromas, contains polyphenols,
It is free of resins and waxes, has a reduced nicotine content of 5 to 50% with respect to the tobacco leaf used and is obtained in yields of 0.8 to 2.5% (anhydrous oil).

Regarding the effect of tobacco flavoring, according to the invention the product isolated from Havana tobacco, for example, is 50 ppm and the aroma product isolated from Havana tobacco by the already known steam distillation is about 250 ppm.
has the same aromatic effect and intensity.

A further object of the invention is the use of the tobacco aroma oil obtained according to the invention for the flavoring of tobacco or tobacco products, in which case this flavoring is not only applied directly to the tobacco but also This can be done by flavoring the porous carrier material or the tobacco adhesive.

When applied directly to tobacco, the tobacco aroma oil according to the invention is suitable for use as a "top flavor" as well as for flavoring weakly aromatic or recycled tobacco depending on the source (casing). There is.

Another method of flavoring consists in applying tobacco aroma oil onto a porous carrier material that is in contact with the tobacco or tobacco product. Such porous carrier materials are present, for example, in the form of pieces of paper or clay, dummies, inner packaging materials (eg cardboard boxes, bags and the like).

As another embodiment of the flavoring by use of the tobacco aroma oil according to the invention, mention should also be made of its addition to adhesives for tobacco production. Examples for this are the adhesives customary for tobacco manufacturing, such as adhesives for cigar outer wraps, double-cut tobacco paper, etc.

The tobacco aroma oil obtained according to the invention decisively influences the variations that may or may occur during the production of cigarettes (differences in quality or differences in smoke aroma).

The amount of tobacco flavoring oil used to flavor tobacco or tobacco products will vary depending on the nature of the tobacco and the desired flavoring. For example, in the case of the aromatic oil obtained according to the invention from Havana tobacco, preferably 25 to 100 mg, particularly preferably 40 to 60 mg, i.e. 25 to 100 ppm, per kg of tobacco;
Preferably 40 to 60 ppm tobacco aroma oil is used.

The excellent efficacy and strength obtained with the products according to the invention are increased in particular by the presence of resin-, polyphenol- and wax-free tobacco aroma oils. This special property of this tobacco aroma oil shows special properties and novel characteristics compared to the prior art.

A particularly suitable apparatus for carrying out the secondary extraction according to the invention is described below (see accompanying drawings).

Liquid CO ₂ is removed from tank 1 at a pressure and temperature below the critical point. By heat exchanger 2
The CO ₂ is adjusted to the desired sub-critical or super-critical temperature and the desired super-critical or sub-critical pressure is obtained by the high pressure pump 3. Through the flow meter 16, the CO ₂ reaches the extraction vessel 4, where extraction of a mixture of primary extract and adsorbent takes place. The loading and unloading of the product into the extraction vessel 4 takes place intermittently by opening and closing the top opening after each extraction. The pressure within the extraction vessel is determined by a pressure valve 14. The liquid or fluid CO ₂ containing the melted tobacco content is led to a pressure regulating valve 8 (=pressure relief valve) via a butterfly valve 6, and then to a heat exchanger 9.
It is introduced into the pressure relief vessel 10 through the. The separation of the tobacco contents dissolved in CO ₂ is initiated by a pressure regulating valve 8 and supported by a reduction in temperature in a heat exchanger 9. The extracted tobacco components are
The clear tobacco aroma oil and the waxy, resinous nicotine product are separated in the expansion vessel 10, and these are separated either continuously via the valve 17 or by opening the vessel 10 after the extraction is completed. removed. At the end of each brew, the brew side of the device is also depressurized by opening valve 5. During extraction, the _CO2 leaving the expansion vessel 10 is recycled via conduit 11. The control of the device is carried out manually or by means of an electric control device 12, which inputs the temperature in the extraction vessel 4, measured by a thermocouple 13, pressure gauges 14 and 15.
The pressure measured at , the flow of CO ₂ leaving pressure vessels 4 and 10 and the flow rate measured at flow meter 7 are used. Depending on these measured values, the cooling in the pressure regulating valve 8 and the heat exchanger 9 is regulated.

If CO ₂ is used as solvent for the primary extraction, the equipment shown and described in the drawings is also used here.

The following examples illustrate the invention without limiting it.

Nicotine was measured by spectroscopic analysis using a method known as H. Kuhn's method (Handbook of Food Chemistry, Vol. 6 (1970), No. 321-325).
(“Handbuck der Lebensmittelchemie” Bd.,
(1970) Seiten 321bis 325)).

Example 1 1000 g of Havana tobacco (water content: 6.5%, nicotine content: 1.27%) are ground in a blade mill and extracted thoroughly in dichloromethane 10, and the solvent is evaporated under reduced pressure of 15 mm Hg.

75 g of a dark syrupy dichloromethane extract (primary extract) containing no solvent was obtained, which was thoroughly mixed with 90 g of sodium aluminum silicate (Na-Al zeolite) in a mixing machine (mixing ratio: 1:1.2).

This mixture was treated with _CO2 for 120 minutes in a closed high-pressure extraction vessel kept at a pressure of 230 bar and a temperature of 65°C. The pressure on the relief side was 50 bar and the temperature was 24°C.

The flow rate of CO ₂ is 6 Kg/hr.

At the end of the experiment, remove the two-phase mixture from the expansion vessel.
40.1 g was removed and separated by simple filtration into 22.5 g of clear oily tobacco aroma oil and 17.6 g of resin/wax precipitate.

The yield of clear anhydrous tobacco aroma oil was 2.25% of the tobacco used. The nicotine content is
19.22%, which was 35% with respect to the nicotine present in tobacco.

The yield of resin/wax precipitate was 1.76% and the nicotine content was 43% (absolute value), or 60% with respect to the nicotine present in the tobacco.

The obtained tobacco aromatic oil did not contain resin or wax, and neither precipitation nor turbidity occurred even when 95% ethanol was added.

Example 2 1000 g of Kentucky tobacco (water content: 8.0%, nicotine content: 1.7%) is ground in a cutting mill and extracted using CO ₂ as a solvent in a CO ₂ high-pressure extraction device (see drawing).

Extraction conditions: Pressure in extraction vessel: 250 bar Temperature in extraction vessel: 40°C Pressure in expansion vessel: 55 bar Temperature in expansion vessel: 22°C Processing time: 3 hours CO ₂ flow rate: 8 Kg/hr End of extraction Afterwards, 70 g of a brown hard paste (primary extract) is removed from the expansion vessel and thoroughly mixed with 140 g of bentonite.

This mixture was prepared under the same conditions as described in Example 1.
Subject to secondary extraction using _CO2 .

After the secondary extraction had ended, 38 g of the two-phase mixture were removed from the expansion vessel and separated by high pressure filtration (5 bar overpressure) into 29 g of the resin/wax mixture and 9 g of clear tobacco aroma oil.

The resulting tobacco aroma oil was free of resins, waxes and polyphenols, and had the characteristic scent of Kentucky tobacco. No turbidity occurred even when 95% ethanol was added.

Example 3 Grind 1000g of Burley tobacco (water content: 7%, nicotine content: 2.85%) with a blade mill,
Exhaustive extraction was carried out in -hexane 6 and the solvent used was evaporated under reduced pressure of 20 mmHg without leaving any residue.

65 g of a dark syrupy primary extract containing no solvent was obtained, which was mixed with 260 g of magnesium oxide.
(Mixing ratio: 1:4).

This mixture was then subjected to an intermediately connected CO ₂ extraction step in a closed high-pressure extraction vessel and then only to a secondary extraction: 1st stage: CO ₂ extraction temperature: -17 °C CO ₂ extraction pressure : 20 bar Temperature in the expansion vessel: +18°C Pressure in the expansion vessel: 8 bar Processing time: 40 minutes The flow rate of CO ₂ is 25 Kg/hr.

After the above processing time had elapsed, 25 g of almost colorless, odorless oil was removed from the expansion vessel. The nicotine content of this oil was 94.1% (absolute value), ie it was 82.5% with respect to the nicotine present in the tobacco.

Second stage (secondary extraction): The same material still present in the extraction vessel was further processed at increased pressure and temperature as follows: CO ₂ extraction temperature: +15 °C CO ₂ extraction pressure: 60 bar expansion Temperature in the vessel: +20° C. Pressure in the expansion vessel: 50 bar Second stage treatment time: 200 minutes The flow rate of CO ₂ was 15 Kg/hr.

After the above processing time has elapsed, the two-phase mixture 29.7
g was removed and separated by simple filtration into 15.5 g of clear tobacco aroma oil and 14.2 g of resin/wax precipitate.

The yield of clear tobacco aroma oil was 1.55% of the tobacco used and the nicotine content was 9.55% (absolute value), ie 5.2% with respect to the nicotine present in the tobacco. The isolated tobacco aroma oil was free of resin and wax, and did not precipitate or become cloudy upon addition of 95% concentration by weight of ethanol.

Example 4 1000 g of Turkish tobacco (Izmir) (water content: 7.2%, nicotine content: 1.45%) were thoroughly extracted in 8 ml of petroleum ether and 15 ml of solvent
Evaporate under reduced pressure of Hg until no residue remains.

Solvent-free dark syrupy primary extract
58 g was obtained, which was thoroughly mixed with 23.2 g of diatomaceous earth (mixing ratio: 1:0.4). This mixture was heated in a closed high-pressure vessel at a pressure of 180 bar and +20 °C.
treated with CO ₂ for 180 min at a temperature of .

The pressure on the relief side is 50 bar and the temperature is +20
It was warm at ℃. The flow rate of CO ₂ is 10Kg/hr.

At the end of the experiment, remove the two-phase mixture from the expansion vessel.
20 g was removed, which was separated by simple filtration into 12 g of clear tobacco aroma oil and 8 g of resin/wax precipitate.

The yield of clear tobacco aroma oil is 1.2% of the tobacco used, and the nicotine content is 23.2
% (absolute value), i.e. 31.5% with respect to the nicotine present in the tobacco.

The isolated tobacco aroma oil was free of resin and wax, and did not precipitate or become cloudy upon addition of 95% ethanol.

Example 5 The results of tobacco aroma oil isolated according to the invention were shown as follows: Clear tobacco aroma oil 0.14%, which did not produce turbidity in ethanol at a concentration of 95% by weight, compared with the known Obtained from the same Havana tobacco used using the steam distillation method. The nicotine content of this aromatic oil is 0.
It was %.

To evaluate the results, one experiment (Experiment A)
In one experiment, 1 kg of pre-deodorized tobacco was sprayed with 200 mg of the above aromatic oil in an ethanol solution, and in another experiment (experiment B), 250 mg was similarly sprayed. Another experiment (experiment C)
In the same manner, 250 mg was sprayed. In another experiment (Experiment C), 50 mg of tobacco aroma oil, isolated according to the invention as in Example 1 and dissolved in a solution of ethanol, was sprayed onto 1 Kg of pre-deodorized tobacco. .

The following results were obtained in the sensory test: Tobacco from Experiment A: This had a noticeably low aroma intensity, and the smoke aroma was not very strong relative to the overall aroma.

Tobacco from Experiment B: This was somewhat strong in aroma, but was accompanied by other aromas, and there was also an undesirable burnt sharpness to the smoke aroma.

Experiment C tobacco: It had a strong, pure, mellow aroma with no other aromas, and had a strong savory flavor in the smoke aroma. Tobacco C is clearly preferred and most suitable for flavoring purposes.

[Brief explanation of drawings]

The drawing shows an example of a device for carrying out the method according to the invention. In the above diagram, the main parts are shown with reference numbers as follows: 1...liquid CO ₂ tank,
2... Heat exchanger, 3... High pressure pump, 4... Extraction vessel, 5... Valve, 6... Butterfly valve, 7... Flow meter,
8... Pressure control valve, 9... Heat exchanger, 10... Expansion vessel, 11... Conduit, 12... Control device, 13
...Thermocouple, 14,15...Pressure gauge, 16...Flowmeter, 17...Valve.

Claims (1)

[Claims] 1. Tobacco extract as a primary extract obtained using a solvent is mixed with an adsorbent, this mixture is subjected to a secondary extraction using CO ₂ in an extraction vessel which is a closed pressure vessel, and By depressurizing in a second sealed pressure vessel, a separation vessel, under conditions of subcritical pressure and temperature, a transparent product that can be easily separated from the resin and wax and has a reduced nicotine content is produced. A method for obtaining tobacco aroma oil from tobacco extract, characterized in that the tobacco aroma oil is isolated. 2. Solvents for preparing the primary extract include benzene, toluene, methanol, ethanol, n
- The process according to claim 1, using propanol, methyl ethyl acetate, diethyl ether, acetone, propane, n-hexane, cyclohexane, petroleum ether, dichloromethane, trichloromethane or a mixture of these solvents or carbon dioxide. . 3. Claim 1, in which magnesium oxide, activated carbon, aluminum oxide, sodium aluminum silicate, bleaching earth, bentonite, silica gel, diatomaceous earth or zeolitic molecular sieve is used as an adsorbent during the secondary extraction. or the method described in Section 2. 4. A method according to any one of claims 1 to 3, using a primary extract:adsorbent mixing ratio of 1:0.1 to 1:10. 5 Perform secondary extraction with _CO2 in the extraction vessel under pressure and temperature conditions above the critical point and below the critical point.
Claims 1 to 4 are carried out either under pressure up to bar and temperature up to +5° C. below the critical point, or under pressure above the critical point and temperature below the critical point. The method described in any one of the above. 6. Any one of claims 1 to 5, wherein a tobacco aroma oil whose nicotine content is reduced to 5 to 50% of the nicotine content of tobacco leaves before primary extraction is obtained. The method described in section. 7. In order to reduce the nicotine content in the tobacco aroma oil to 5 to 10% of the nicotine content of the tobacco leaves before the primary extraction, the secondary extraction with CO ₂ is carried out in two steps: a -25 in the extraction vessel a first extraction stage with CO ₂ at a temperature of from 0° C. to +5° C. and a pressure of about 20 to 25 bar, and b then the pressure and temperature in said extraction vessel is reduced to 25
The second temperature rises above Bar and above 5°C.
7. A method according to any one of claims 1 to 6, carried out in the extraction step. 8 Any one of claims 1 to 7, in which the secondary extraction with CO ₂ is performed for 0.5 to 8 hours.
The method described in section. 9. In the secondary extraction, tobacco extract is extracted at a rate of 0.3 to 35 kg/hr per 1 kg of tobacco.
9. A method according to any one of claims 1 to 8, using _CO2 . 10 separating the product obtained during the secondary extraction in a separation vessel by filtration into resin and wax on the one hand and into clear tobacco aroma oil on the other hand;
A method according to any one of claims 1 to 9.