GB1593729A - Method of making a cigarette having relative filling power and a cigarette made thereby - Google Patents

Description

(54) A METHOD OF MAKING A CIGARETTE HAVING IMPROVED RELATIVE FILLING POWER, AND A CIGARETTE MADE THEREBY (71) We, IMPERIAL GROUP LIMITED, a British Company of Imperial House, 1 Grosvenor Place, London SW1X 7HB, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention concerns a method of making a cigarette having improved relative filling power and a cigarette made thereby.

It is known to expand tobacco to produce an overall increase in filling capacity of smoking tobacco, as measured by decrease in cigarette density necessary to achieve constant firmness, by moistening already moistened out tobacco lamina at 21% W/W moisture content to about 33% W/W moisture content and then drying back to about 16% W/W moisture content. Firmness is an important parameter which influences manufacturing-economics and consumer acceptability, and is described as the degree of flattening of a cigarette under constant compression. Firmness is expressed by dividing the mean density of an experimental cigarette into the density of a control cigarette at the same flattening and expressing it as a percentage.

During drying of the double wetted lamina from 33% W/W to 16% W/W using conventional gas fired rotary driers the increase in filling capacity reaches a maximum of about 9% as measured by density reduction, but is reduced to a level of about 4-5% at the exit of the drier. This is though to be due to shrinkage of the expanded cellular structure of the tobacco during the final stage.

It is an object of the present invention to provide a method whereby shrinkage of the expanded cellular-structure of the tobacco is reduced during drying.

According to a first aspect of the present invention there is provided a method of making a cigarette having improved relative filling power comprising the steps of, (a moistening tobacco parts selected from lamina, mid-rib and stem to a first level of moisture content, (b) cutting the tobacco parts, (c) further moistening the cut parts to a second level of moisture content, thereby expanding the cut parts, (d) simultaneously with the further moistening, adding to the cut parts a water soluble pectin to impregnate the cut parts therewith, (e) drying the cut tobacco parts, and (f) making up the dried cut impregnated tobacco parts into a cigarette.

According to a second aspect of the present invention there is provided a cigarette containing expanded cut tobacco parts having a fibrous structure which has been impregnated with a water soluble pectin and subsequently dried, being produced according to the method of the first aspect, whereby the area and spacing between the fibres of said fibrous structure is increased, relative to the area and spacing prior to expansion and said pectin binds to the fibres of said fibres structure, bonding and reinforcing the fibrous structure and decreasing the tendency of the fibrous structure to shrink on drying.

The invention will now be described by way of example with reference to the following examples in each of which there is described, (a) the preparation of a contrl cigarette made from single wetted tobacco, (b) the preparation of a control cigarette made from double wetted tobacco, (c) the preparation of a cigarette made from tobacco treated according to the invention, and given the results of comparative firmness tests.

Firmness is measured on a modified Masons Firmness Integrator by applying a 60 gm load across a cigarette for 0.5 seconds. The Integrator produces a series of "counts", the number of which is indicative of the deformation or flattening of the cigarette by the load.

The Relative Filling Power of a blend relative to a control is calculated by the following procedure: 1. The mean number of counts per cigarette is observed (Fobs).

2. Cigarettes vary slightly in circumference, so it is necessary to correct the count (Fobs) to the "real" count (Fr) for a standard circumference cigarette. This is given by the formula Fr = Fohs -54.31 + 2.08C where C is the circumference of the cigarette in mm.

3. The Oven Dry Density (ODD) of the tobacco in a set of cigarettes is calculated from the formula WB - 5Wp (100-m) 4# ODD = x x x 106 g/kcc 50 100 C2L where WB = the bulk weight of 50 cigarettes Wp = the plug and paper weight of 10 cigarettes M = the percentage moisture of the tobacco C = the mean circumference of each cigarette L = the rod length of each cigatrette 4. To calculate the Relative Filling Power of a blend relative to that of a control, the Oven Dry Density of the experimental blend (ODDexp) is corrected to the same firmness as the control blend, using the following experimental formula derived from several sets of observations. It will be understood that the coefficients in the formula will vary according to the Firmness Integrator used to obtain a measure of "flattening".

ODD (at control firmness Fr(con,rol)) = ODD(exp) . In (0.01437 Fr(control)) In (Fr(exp) - 4.2426) where Fr(exp) = real firmness count of experimental blend rcontrol) = real firmness of control blend ODD eXo) = ODD of experimental blend at firmness Fr(exp) The 20 Relative Filling Power of experimental blend relative to the control blend then = ODD(Control) x 100 at the same firmness ODD Example 1 (a) Single wetted control.

Tobacco lamina initially having a moisture content of 16% W/W was moistened to 21% W/W and cut, and then dried back to 13.6% W/W moisture content. The cut dried lamina was made up into cigarettes the deformation which was measured on the Integrator and then taken as representing a Relative Filling Power of 100%.

(b) Double wetted control Tobacco lamina initially having a moisture content of 16% W/W was moistened to a moisture content of 21% W/W and then cut. The moistened cut lamina was then further moistened to 33% W/W and then dried back to 13.7% W/W moisture content. The cut dried lamina was made up into cigarettes the deformation of which was measured on the Integrator and calculated to represent a Relative Filling Power as a percentage relative to that of the single wetted control.

(c) Double wetted tobacco and pectin Tobacco lamina initially having a moisture content of 16% W/W was moistened to a moisture content of 21% and then cut. The moistened cut lamina was then further moistened to 33% W/W and simultaneously 1% W/W citrus pectin having a methoxyl content of 55-60% was added to the tobacco. The lamina was then dried back to a moisture content of 13.6% W/W. The cut dried lamina was made up into cigarettes the deformation of which was measured on the Integrator and calculated to represent a Relative Filling Power as a percentage relative to that of the single wetted control.

The results were tabulated as follows: Oven dried density Fr Tobacco Cigarette of cigarette kg/m3 moisture % Relative Filling Power % at same firmness (a) Conventional single wetted 235.6 4.245 13.6 100 control (b) Double wetted control (no pectin 233.9 3.529 13.7 107.3 (c) Double wetted tobacco and pectin 233.6 3.408 13.6 108.7 Example 2 (a) Single wetted control.

Tobacco lamina was treated as in Example 1(a) except that it was dried back to a moisture content of 12.9% W/W. The deformation was measured as before.

(b) Double wetted control.

Tobacco lamina was double wetted as in Example 1 (b) except that it was dried back to a moisture content of 13.2% W/W. The deformation was measured as before.

(c) Double wetted tobacco and pectin.

Tobacco lamina was double wetted and cut as in Example 1 (c) except that at the double wetting stage 1.5% W/W of citrus pectin having a methoxyl content of 55-60% was added, and the tobacco was finally dried back to a moisture content of 12.9%. The deformation was measured as before.

The results were tabulated as follows: Oven dried density Fr Tobacco Cigarette of cigarette kg/m3 moisture % Relative Filling Power % at same firmness (a) Conventional single wetted 233.5 3.825 12.9 100 control (b) Double wetted control (no pectin) 230.2 3.761 13.2 102.1 (c) Double wetted tobacco and pectin 231.4 3.317 12.9 105.9 It is found that the double moistening expands the tobacco by about 9% and that addition of the pectin to the tobacco causes this expansion to be not only maintained during drying but to be substantially permanent thereafter. It is believed that the pectin solution penetrates the intercellular structure and, during drying, forms a film that strengthens and stiffens the tobacco. It is further believed that the pectin crosslinks with calcium and magnesium salts present in the tobacco, thus providing a strong, water insoluble film.

Water soluble natural gums other than citrous pectin may be used, for example pectins with similar degrees of methylation derived from apple or sugar beet sources.

WHAT WE CLAIM IS: 1. A method of making a cigarette having improved relative filling power comprising the steps of, (a) moistening tobacco parts selected from lamina, mid-rib and stem to a first level of moisture content, (b) cutting up tobacco parts, (c) further moistening the cut parts to a second level of moisture content, thereby expanding the cut parts, (d) simultaneously with the further moistening, adding to the cut parts a water soluble pectin to impregnate the cut parts therewith, (e) drying the cut tobacco parts, and (f) making up the dried out impregnated tobacco parts into a cigarette.

2. A method as claimed in claim 1 wherein the pectin has a degree of methylation between 30-60%.

3. A method as claimed in claim 2 wherein the pectin is a citrus pectin having a methoxyl content of 55-60%.

4. A method as claimed in claim 3 wherein the amount of pectin added at step (d) is not more than 2% W/W.

5. A method as claimed in any preceding claim wherein the first moisture level is about 21% W/W.

6. A method as claimed in any preceding claim wherein the second moisture level is about 33% W/W.

7. A cigarette containing expanded cut tobacco parts having a fibrous structure which has been impregnated with a water-soluble pectin and subsequently dried, being produced according to the method as claimed in any preceding claim, whereby the area and spacing between the fibres of said fibrous structure is increased, relative to the area and spacing prior to expansion and said pectin binds to the fibres of said fibrous structure, bonding and reinforcing the fibrous structure and decreasing the tendency of the fibrous structure to shrink on drying.

8. A method of making a cigarette having improved relative filling power as hereinbefore described with reference to part (c) of Example 1 or part (c) of Example 2.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. It is found that the double moistening expands the tobacco by about 9% and that addition of the pectin to the tobacco causes this expansion to be not only maintained during drying but to be substantially permanent thereafter. It is believed that the pectin solution penetrates the intercellular structure and, during drying, forms a film that strengthens and stiffens the tobacco. It is further believed that the pectin crosslinks with calcium and magnesium salts present in the tobacco, thus providing a strong, water insoluble film. Water soluble natural gums other than citrous pectin may be used, for example pectins with similar degrees of methylation derived from apple or sugar beet sources. WHAT WE CLAIM IS:

1. A method of making a cigarette having improved relative filling power comprising the steps of, (a) moistening tobacco parts selected from lamina, mid-rib and stem to a first level of moisture content, (b) cutting up tobacco parts, (c) further moistening the cut parts to a second level of moisture content, thereby expanding the cut parts, (d) simultaneously with the further moistening, adding to the cut parts a water soluble pectin to impregnate the cut parts therewith, (e) drying the cut tobacco parts, and (f) making up the dried out impregnated tobacco parts into a cigarette.

2. A method as claimed in claim 1 wherein the pectin has a degree of methylation between 30-60%.

3. A method as claimed in claim 2 wherein the pectin is a citrus pectin having a methoxyl content of 55-60%.

4. A method as claimed in claim 3 wherein the amount of pectin added at step (d) is not more than 2% W/W.

5. A method as claimed in any preceding claim wherein the first moisture level is about 21% W/W.

6. A method as claimed in any preceding claim wherein the second moisture level is about 33% W/W.

7. A cigarette containing expanded cut tobacco parts having a fibrous structure which has been impregnated with a water-soluble pectin and subsequently dried, being produced according to the method as claimed in any preceding claim, whereby the area and spacing between the fibres of said fibrous structure is increased, relative to the area and spacing prior to expansion and said pectin binds to the fibres of said fibrous structure, bonding and reinforcing the fibrous structure and decreasing the tendency of the fibrous structure to shrink on drying.

8. A method of making a cigarette having improved relative filling power as hereinbefore described with reference to part (c) of Example 1 or part (c) of Example 2.