IMPROVED METHOD OF PRODUCING A LIQUID TOBACCO EXTRACT

Abstract

A method of producing a liquid tobacco extract is provided, the method including the steps of: preparing a tobacco material; heating the tobacco material in an extraction chamber at an extraction temperature of between 120 degrees Celsius and 160 degrees Celsius for at least 90 minutes; spraying atomised water into the extraction chamber during the heating step; collecting volatile compounds released from the tobacco material during the heating step; and forming a liquid tobacco extract comprising the collected volatile compounds. A liquid tobacco extract produced by the method is also provided.

Claims

1.-15. (canceled)

16. A method of producing a liquid tobacco extract, the method comprising the steps of: preparing a tobacco material; heating the tobacco material in an extraction chamber at an extraction temperature of between 120 degrees Celsius and 160 degrees Celsius for at least 90 minutes; spraying atomised water into the extraction chamber during the heating step; collecting volatile compounds released from the tobacco material during the heating step; and forming a liquid tobacco extract comprising the collected volatile compounds.

17. The method according to claim 16, wherein the spraying of atomised water produces a turbulent gas flow within the extraction chamber.

18. The method according to claim 16, wherein the atomised water is sprayed continuously into the extraction chamber during the heating step.

19. The method according to claim 16, wherein the atomised water is sprayed into the extraction chamber at a rate of at least 0.2 grams per second.

20. The method according to claim 16, wherein an average flow rate of the atomised water sprayed into the extraction chamber during the heating step is between 3 percent and 30 percent of a flow rate of the tobacco material through the extraction chamber.

21. The method according to claim 16, wherein the atomised water is atomised in a flow of compressed inert gas.

22. The method according to claim 16, wherein the atomised water is sprayed into the extraction chamber at a pressure of at least 1 bar.

23. The method according to claim 16, wherein the tobacco material is continuously circulated within the extraction chamber during the heating step.

24. The method according to claim 16, wherein an amount of nicotine extracted from the tobacco material during the heating step corresponds to at least 2 grams per kg of dry tobacco material.

25. The method according to claim 16, wherein the tobacco material is heated in a flow of inert gas during the heating step.

26. The method according to claim 16, wherein the tobacco material is heated at an extraction temperature of between 130 degrees Celsius and 150 degrees Celsius.

27. The method according to claim 16, further comprising the step of subjecting the tobacco material to an alkali treatment prior to the heating step.

28. The method according to claim 16, wherein the tobacco material is microwave heated during at least one step of the method.

29. The method according to claim 16, further comprising the step of drying or concentrating the collected volatile compounds.

30. A liquid tobacco extract produced by the method according to claim 16.

Description

COMPARATIVE EXAMPLE

[0171] In a method according to the present invention, a tobacco material was cut to form tobacco shreds having maximum dimensions of 2.5 millimetres by 2.5 millimetres and the tobacco shreds were loaded into an extraction chamber, without compression. The tobacco material was heated within the extraction chamber to a temperature of 140 degrees Celsius for a period of 120 minutes. During heating, a flow of nitrogen was passed through the extraction chamber at a flow rate of about 20 litres per minute. The tobacco flow rate was 30 kg per hour and the extraction chamber was rotated at a speed of 1 rpm in order to circulate the tobacco.

[0172] During the heating step, atomised water was sprayed continuously into the extraction chamber at a rate of approximately 0.5 grams per second, with a pressure of 1 bar and a temperature of 22 degrees Celsius.

[0173] The volatile compounds released from the tobacco material during the heating step were collected by condensation at 0 degrees Celsius and dissolved in propylene glycol.

[0174] The Nicotine Composition 1 shown in the table below is a liquid tobacco extract obtained directly from the extraction process according to the present invention, with the water spraying step.

[0175] In a second, comparative extraction method, the tobacco material was kept at a water content of about 10 percent o.v. (oven volatiles) and the tobacco material was extracted under the same conditions as described above, except that the water spraying step was omitted. The second extraction method was therefore not according to the present invention. The Nicotine Composition 2 shown in the table below is a liquid tobacco extract obtained directly from this second extraction method.

[0176] In a third, comparative extraction method, the tobacco material was moistened prior to the heating step to a water content of 20 percent o.v. (oven volatiles) and the moistened tobacco material was extracted under the same conditions as described above, except that the water spraying step was omitted. The third extraction method was therefore not according to the present invention. The Nicotine Composition 3 shown in the table below is a liquid tobacco extract obtained directly from this third extraction method.

[0177] Each of the nicotine compositions was analysed to measure the nicotine content and the nicotine yield was calculated based on the total dry weight of the tobacco material. The extraction yield of certain flavour compounds was also measured. The results of this analysis are shown in the table below:

TABLE-US-00001 Nicotine Nicotine Nicotine Composition Composition Composition 1 2 3 Nicotine extraction yield 3.4 1.6 2.0 (g/kg of dry tobacco) Sotolone extraction yield 42 25 n/a (g/kg of dry tobacco) 2-phenylethanol 5907 5101 n/a extraction yield (g/kg of dry tobacco) 3-methylbutanoic acid 2685 2327 n/a extraction yield (g/kg of dry tobacco) 2-methylbutanoic acid 3132 3043 n/a extraction yield (g/kg of dry tobacco)

[0178] As clearly shown in the table above, the inclusion of the water spraying step in the method according to the invention provides a significant increase in the nicotine extraction yield compared to the methods in which the water spraying step is omitted. The comparison between the nicotine yield for Nicotine Compositions 1 and 3 also demonstrates that the improvement in the nicotine yield is provided specifically by the spraying of atomised water, since the same increase in nicotine yield is not observed when the tobacco material is moistened prior to heating, as in the third comparative method above. As also shown in the table above, the inclusion of the water spraying step provides a significantly improved extraction yield for certain flavour compounds, including sotolone by 68%, 2-phenylethanol by 16%, 3-methylbutanoic acid by 15% and 2-methylbutanoic acid by 3%.