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 starting material including natural tobacco material such that during the step of preparing the tobacco starting material, the tobacco is not subjected to any treatment adapted to alter the pH of the tobacco; heating the tobacco starting material in a flow of inert gas at an extraction temperature of between 125 degrees Celsius and 160 degrees Celsius for between 90 minutes and 270 minutes; collecting volatile compounds released from the natural tobacco starting material during the heating step; and forming a liquid tobacco extract comprising the collected volatile compounds.

Claims

1.-15. (canceled)

16. A method of producing a liquid tobacco extract, the method comprising the steps of: preparing a tobacco starting material comprising natural tobacco material, wherein in the step of preparing the tobacco starting material, the tobacco is not subjected to any treatment adapted to alter the pH of the tobacco; heating the tobacco starting material in a flow of inert gas at an extraction temperature of between 125 degrees Celsius and 160 degrees Celsius for between 90 minutes and 270 minutes; collecting volatile compounds released from the natural tobacco starting 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 tobacco starting material is heated at an extraction temperature of between 125 degrees Celsius and 140 degrees Celsius.

18. The method according to claim 17, wherein the tobacco starting material is heated at the extraction temperature for at least 120 minutes.

19. The method according to claim 17, wherein the extraction temperature is selected to provide a liquid tobacco extract having a nicotine content of at least 0.2 percent by weight based on dry weight.

20. The method according to claim 17, wherein the extraction temperature is selected to provide a ratio by weight of (β-ionone+β-damascenone) to (phenol) of at least about 0.25.

21. The method according to claim 17, wherein the extraction temperature is selected to provide a ratio by weight of (furaneol+(2,3-diethyl-5-methylpyrazine)*100)) to (nicotine) of at least about 5×10.sup.−4.

22. The method according to claim 16, wherein the tobacco starting material is impregnated with an aerosol former before the heating step.

23. The method according to claim 16, wherein the volatile compounds are collected by condensation.

24. The method according to claim 16, wherein the volatile compounds are collected by absorption into a liquid solvent comprising an aerosol former.

25. The method according to claim 24, wherein the aerosol former comprises glycerin, propylene glycol, or a combination thereof.

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

27. The method according to claim 16, wherein the step of preparing the tobacco starting material comprises grinding the tobacco material to form a tobacco powder.

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

Description

EXAMPLE 1

[0149] A tobacco starting material is prepared from a flue-cured Bright tobacco material. The tobacco material is cut to form tobacco shreds having dimensions of 2.5 millimetres by 2.5 millimetres and the tobacco shreds are loaded into an extraction chamber, without compression. The tobacco starting material is heated within the extraction chamber to a temperature of 130 degrees Celsius for a period of 3 hours. During heating, a flow of nitrogen is passed through the extraction chamber at a flow rate of about 40 litres per minute.

[0150] The volatile compounds released from the tobacco starting material during the heating step are collected by absorption into a liquid solvent formed of propylene glycol at minus 10 degrees Celsius and with agitation of 750 rpm.

[0151] The nicotine composition of Example 1 is a liquid tobacco extract obtained directly from an extraction process at a temperature of 130 degrees Celsius for a period of 3 hours. The nicotine composition provides an optimised level of desirable flavour compounds such as β-damascenone and β-ionone to undesirable compounds such as phenol, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, (R,S)—N-nitrosoanatabine, (R,S)—N-nitrosoanabasine, N-nitrosonornicotine and 2-furanemethanol. The nicotine composition further provides a level of desirable flavour compounds such as furaneol and 2,3-diethyl-5-methylpyrazine to nicotine. The solution of propylene glycol with the collected volatile compounds is concentrated in a desiccation process to reduce the moisture level of the liquid tobacco extract to approximately 15 percent.

EXAMPLE 2

[0152] This example provides two nicotine compositions in accordance with the invention, both of which are liquid tobacco extracts obtained directly from an extraction process at a temperature of 130 degrees Celsius for a period of 3 hours.

EXAMPLE 2a

[0153] Example 2a relates to a liquid tobacco extract derived from flue-cured Bright tobacco material. The content of the concentrated liquid tobacco extract of Example 2a is as follows: [0154] Nicotine: 0.53% w/w [0155] Propylene Glycol: 91.8% w/w [0156] Water: 6.3% w/w [0157] Balance (including flavourants as detailed in Table 1 below): 1.57% w/w

EXAMPLE 2b

[0158] Example 2b relates to a liquid tobacco extract derived from Burley tobacco material. The content of the concentrated liquid tobacco extract of Example 2b is as follows: [0159] Nicotine: 1.82% w/w [0160] Propylene Glycol: 89.6% w/w [0161] Water: 5.7% w/w [0162] Balance (including flavourants as detailed in Table 1 below): 2.88% w/w

TABLE-US-00001 TABLE 1 Content of selected flavour compounds in liquid tobacco extract (all values given in micrograms per kilogram of liquid tobacco extract) 2,3- 2-ethyl- 2- 3- 3-methyl- 2- β- diethyl- 3,5- methyl- methyl- 2,4- meth- 2- Ex- Acetic β- damasce- 5-methyl- dimethyl- butanoic butanoic nonane- oxy- phenyl- ample acid ionone none furaneol pyrazine Vanillin pyrazine acid acid dione phenol ethanol Eugenol sotolone 2a 6193580 1352 2995 2420  39 1040  838 14081 20114 273 1649 19875 619 85 2b 3868247  939 1139  154 478  340 1980 16209 36356  69 3169 18196 845 36

[0163] The nicotine compositions of Examples 2a and 2b in accordance with the invention contain acceptably low levels of undesirable compounds such as phenol, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, (R,S)—N-nitrosoanatabine, (R,S)—N-nitrosoanabasine, N-nitrosonornicotine and 2-furanemethanol.

EXAMPLE 3

[0164] This example provides three nicotine compositions in accordance with the invention, each of which is a liquid tobacco extract obtained directly from an extraction process at a temperature of 130 degrees Celsius for a period of 3 hours.

EXAMPLE 3a

[0165] Example 3a relates to a liquid tobacco extract derived from oriental Bright tobacco material. The content of the liquid tobacco extract of Example 3a is as follows: [0166] Nicotine: 0.4% w/w [0167] Propylene glycol: 84% w/w [0168] Acetic Acid: 1.0% w/w [0169] Water: 12.5% w/w [0170] Balance (including flavourants): 2.1% w/w

EXAMPLE 3b

[0171] Example 3b relates to a liquid tobacco extract derived from flue-cured Bright tobacco material. The content of the liquid tobacco extract of Example 3b is as follows: [0172] Nicotine: 1.2% w/w [0173] Propylene Glycol: 84% w/w [0174] Acetic acid: 1.0% w/w [0175] Water: 12.5% w/w [0176] Balance (including flavourants): 1.3% w/w

EXAMPLE 3c

[0177] Example 3c relates to a liquid tobacco extract derived from Burley tobacco material. The content of the liquid tobacco extract of Example 3c is as follows: [0178] Nicotine: 2.6% w/w [0179] Propylene Glycol: 84% w/w [0180] Acetic acid: 0.5% w/w [0181] Water: 12.5% w/w [0182] Balance (including flavourants): 0.4% w/w

[0183] The nicotine compositions of Example 3 provide an optimised level of desirable flavour compounds such as β-damascenone and β-ionone to undesirable compounds such as phenol, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, (R,S)—N-nitrosoanatabine, (R,S)—N-nitrosoanabasine, N-nitrosonornicotine and 2-furanemethanol. The nicotine compositions further provide a level of desirable flavour compounds such as furaneol and 2,3-diethyl-5-methylpyrazine to nicotine.

EXAMPLE 4

[0184] The liquid tobacco extract of Example 1 was concentrated in a desiccation process to reduce the moisture level of the liquid tobacco extract to approximately 15 percent.

[0185] Glycerine was added to the resultant concentrated liquid tobacco extract to form the nicotine composition, such that the nicotine composition contained 20 percent by weight glycerine and 80 percent by weight liquid tobacco extract, based on the weight of the nicotine composition.

EXAMPLE 5

[0186] Example 4 relates to a nicotine composition in the form of a gel in accordance with the invention. The gel nicotine composition is formed from the liquid tobacco extract of Example 1.

[0187] The content of the gel nicotine composition is as follows: [0188] Liquid tobacco extract of Example 1: 99.0% w/w [0189] Agar: 1.0% w/w

EXAMPLE 6

[0190] Three tobacco starting materials are prepared from a flue-cured Bright tobacco material (6A), a Burley tobacco material (6B), and an Oriental tobacco material (6C), respectively.

[0191] Each one of the three tobacco materials is cut to form tobacco shreds having dimensions of 2.5 millimetres by 2.5 millimetres, and the tobacco shreds are loaded into an extraction chamber, without compression.

[0192] Each one of the tobacco starting materials is heated within the extraction chamber to a temperature of 130 degrees Celsius for a period of 120 minutes. During heating, a flow of nitrogen is passed through the extraction chamber at a flow rate of 2 litres per minute.

[0193] The volatile compounds released from each tobacco starting material during the heating step are collected by absorption into a liquid solvent formed of polypropylene glycol at 0 degrees Celsius.

[0194] A liquid tobacco extract is obtained directly from such extraction process. Each liquid extract obtained from each one of the three tobacco starting materials is then concentrated under vacuum (50 mbar) at 55 degrees Celsius until a moisture content of 12 percent±2 percent is reached.

TABLE-US-00002 TABLE 2 Value of selected ratios by weight of desirable to undesirable tobacco compounds within the liquid tobacco extracts (β-ionone + β- damascenone) to (4- (methylnitrosamino)-1-(3- pyridyl)-1-butanone + (furaneol + (R,S)-N-nitrosoanatabine + (2,3-diethyl- (R,S)-N- (β-ionone + β- 5-methylpyr- nitrosoanabasine + N- damascenone) to azine)*100)) nitrosonornicotine + ((2- Example (phenol) to (nicotine) furanemethanol)/600)) 6A 2.27 1.35 × 10.sup.−3 5.25 6B 2.96 1.71 × 10.sup.−3 3.50 6C 4.12 2.75 × 10.sup.−3 7.83

[0195] In all three liquid extracts in accordance with the invention 6A, 6B, and 6C the ratio by weight of (β-ionone+β-damascenone) to (phenol) is consistently and significantly above 2.0. Further, in all three liquid extracts in accordance with the invention 6A, 6B, and 6C the ratio by weight of (furaneol+(2,3-diethyl-5-methylpyrazine)*100)) to (nicotine) is consistently and significantly above 1×10.sup.−3. Additionally, in all three liquid extracts in accordance with the invention 6A, 6B, and 6C the ratio by weight of (β-ionone+β-damascenone) to (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone+(R,S)—N-nitrosoanatabine+(R,S)—N-nitrosoanabasine+N-nitrosonornicotine+((2-furanemethanol)/600)) is consistently and significantly above 3.