Cigarette

Cigarettes having high nicotine content tobacco cut filler are rendered smooth smoking and palatable by incorporating an organic acid salt additive therein. For example, a cigarette having a cut filler with a blend nicotine content of greater than 2 percent has a sodium levulinate additive combined with the tobacco cut filler of the cigarette. Smooth smoking cigarettes yielding good tobacco taste and minimal off-taste are provided.

BACKGROUND OF THE INVENTION 
The present invention relates to cigarettes and other such types of smoking 
articles, and in particular to those smoking articles having at least one 
salt of an organic acid incorporated therein. 
Cigarettes are popular smoking articles which have a substantially 
cylindrical rod shaped structure and include a charge of tobacco (i.e., in 
cut filler form) surrounded by a wrapper, such as paper, thereby forming a 
tobacco rod. Currently, popular cigarettes include blends of tobacco 
materials, the majority of the blends having nicotine contents in the 
range from about 1.2 percent to about 2.25 percent, more frequently from 
about 1.4 percent to about 2 percent, and most frequently from about 1.6 
percent to about 1.8 percent, based on the dry weight of the tobacco 
materials. It has become desirable to manufacture a cigarette having a 
cylindrical filter element aligned in an end-to-end relationship with the 
tobacco rod. Typically, a filter element is manufactured from fibrous 
materials (e.g., cellulose acetate tow) and is circumscribed by plug wrap, 
attached to the tobacco rod using a circumscribing tipping material. 
Popular cigarettes classified as "full flavor" cigarettes deliver a 
desirable tobacco taste, flavor and satisfaction to the smoker. Typically, 
the "full flavor" cigarettes yield about 14 mg or more of FTC "tar" per 
cigarette. A second classification of popular cigarettes is the "full 
flavor low tar" classification. Typically, the "full flavor low tar" 
cigarettes yield from about 8 to about 14 mg of FTC "tar" per cigarette, 
as well as lower levels of FTC nicotine as compared to "full flavor" 
cigarettes. A third classification of popular cigarettes is the "ultra low 
tar" classification. Such "ultra low tar" cigarettes yield still lower 
levels of FTC "tar" and nicotine. Typically, the "ultra low tar" 
cigarettes yield less than about 7 mg of FTC "tar" per cigarette. The 
"full flavor low tar" and "ultra low tar" cigarettes conventionally are 
air diluted (e.g., provided with mechanical or laser perforations in the 
periphery of the mouthend region thereof), or have filter elements highly 
efficient for the removal of "tar" and nicotine from the mainstream smoke. 
In general, the perceived taste or strength of the cigarettes classified as 
having lower levels of "tar" and nicotine are progressively less than that 
of the cigarettes which are classified as approaching the characteristics 
of the "full flavor" cigarettes. It has been proposed to add numerous 
flavorants to the cut filler of lower "tar" cigarettes to enhance the 
taste, strength and satisfaction of such cigarettes. However, such 
addition generally yields mainstream smoke which may be perceived as harsh 
or irritating to the mouth, nose and throat of the smoker. 
Additionally, it is possible to employ tobaccos having a naturally high 
nicotine content as cut filler to enhance the tobacco taste, strength and 
satisfaction of such cigarettes. However, cigarettes having high nicotine 
contents (e.g., which include tobacco blends having natural nicotine 
contents above about 2.25 weight percent) generally have the propensity to 
yield unpalatable mainstream smoke which may be perceived as harsh or 
irritating to the mouth, nose and throat of the smoker. 
It would be desirable to provide a cigarette such as an "ultra low tar" 
cigarette which is capable of delivering a good tobacco taste, strength 
and smoking satisfaction characteristic of a "full flavor low tar" 
cigarette while being perceived as palatable but not as overly harsh or 
irritating. In addition, it would be desirable to provide a cigarette, 
such as a "full flavor low tar" cigarette, which is capable of delivering 
a good tobacco taste, strength and smoking satisfaction characteristic of 
a "full flavor" cigarette while being perceived as palatable but not as 
overly harsh or irritating. Furthermore, it would be desirable to improve 
the smoking character of cigarettes which employ tobaccos or other tobacco 
materials having a wide range of nicotine contents. 
SUMMARY OF THE INVENTION 
The present invention relates to a smoking article which delivers good 
tobacco taste while being capable of delivering relatively low amounts of 
FTC "tar." Preferred articles of this invention are cigarettes which 
deliver taste, strength and smoking satisfaction characteristic of "full 
flavor" cigarettes, and relatively low levels of FTC "tar" characteristic 
of "full flavor low tar" cigarettes. Also preferred are cigarettes which 
deliver taste, strength and smoking satisfaction characteristic of "full 
flavor low tar" cigarettes, and relatively low levels of FTC "tar" 
characteristic of "ultra low tar" cigarettes. In addition, the preferred 
cigarettes are extremely palatable and provide the perception of having a 
smooth smoking character (i.e., not providing a perceived harsh or 
irritating character) relative to a comparable cigarette yielding similar 
levels of FTC "tar." Of particular interest are cigarettes having (i) 
relatively low FTC "tar" to FTC nicotine ratios, (ii) relatively low FTC 
carbon monoxide to FTC nicotine ratios, (iii) good tobacco flavor, 
strength and satisfaction, and (iv) a smooth, palatable smoking character 
without being overly mild tasting. 
A cigarette of the present invention includes a smokable material contained 
in a circumscribing outer wrapping material. The cigarette includes (i) 
smokable (e.g., tobacco) material, and (ii) an additive in the form of at 
least one inorganic salt of an organic acid in contact with the smokable 
material. For example, a highly preferred cigarette of the present 
invention includes (i) a smokable material having a nicotine content above 
about 2 percent, based on the dry weight of the smokable material, and 
(ii) an inorganic salt of levulinic acid in contact with at least a 
portion of the smokable material. The amount of the inorganic salt of 
levulinic acid which is added to the smokable material generally is such 
that the smokable material includes greater than about 0.01 percent, more 
preferably greater than about 0.75 percent, of levulinate moiety (i.e., 
anionic moiety), based on the dry weight of the smokable material. 
Preferred cations useful for providing the inorganic salt of levulinic 
acid include the alkali metal and alkali earth metal ions. 
As used herein, the term "dry weight" in referring to the smokable material 
of the smoking article is meant the mass of the smokable material after 
being dried to constant weight at 214.degree. F. (101.degree. C.) for 3 
hours in a force-draft oven. See, Moseley et al, Ind. Eng. Chem., Vol. 43, 
p. 2342 (1951). 
As used herein, the term "nicotine content" in referring to the smokable 
material is meant the mass alkaloid nicotine as analyzed and quantitated 
by spectroscopic techniques divided by the dry weight of the smokable 
material analyzed. See, Harvey et al, Tob. Sci., Vol. XXV, p. 131 (1981). 
The smokable material from which cigarettes of the present invention are 
manufactured conveniently can be a cut filler material composed of one or 
more tobacco materials having a naturally high nicotine content. Such 
naturally high nicotine content tobacco materials can be employed alone or 
as blends with (i) one or more tobacco materials having low nicotine 
contents, and/or (ii) one or more other smokable materials. As such, 
preferred cigarettes of the present invention include those cigarettes 
wherein the smokable material thereof exhibits a total nicotine content, 
or blend nicotine content, above about 2 percent. 
The presence of an inorganic salt of levulinic acid within a cigarette 
having a relatively high nicotine content provides improved tobacco taste, 
strength and smoking satisfaction as well as improved or maintained flavor 
characteristics to mainstream smoke of that cigarette during smoking. 
Preferred cigarettes of this invention do not exhibit undesirable 
off-tastes during smoking. The inorganic salt of levulinic acid also has a 
propensity not to migrate from the smokable material with which the salt 
is contacted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
One embodiment of the present invention is shown in FIG. 1, and has the 
form of a cigarette 10. The cigarette includes a generally cylindrical rod 
15 of smokable material 20, such as tobacco cut filler, contained in 
circumscribing outer wrapping material 25. The rod 15 is hereinafter 
referred to as a "tobacco rod." The ends of the tobacco rod are open to 
expose the smokable material. The cigarette 10 also includes a filter 
element 30 positioned adjacent one end of the tobacco rod 15 such that the 
filter element and tobacco rod are axially aligned in an end-to-end 
relationship, preferably abutting one another. Filter element 30 has a 
generally cylindrical shape, and the diameter thereof is essentially equal 
to the diameter of the tobacco rod. The ends of the filter element are 
open to permit the passage of air and smoke therethrough. The filter 
element 30 includes filter material 35 which is overwrapped along the 
longitudinally extending surface thereof with circumscribing plug wrap 
material 40. 
The filter element 30 is attached to the tobacco rod 15 by tipping material 
45 which circumscribes both the entire length of the filter element and an 
adjacent region of the tobacco rod. The inner surface of the tipping 
material 45 is fixedly secured to the outer surface of the plug wrap 40 
and the outer surface of the wrapping material 25 of the tobacco rod, 
using a suitable adhesive. If desired, a ventilated or air diluted 
cigarette is provided with an air dilution means such as a series of 
perforations 50 each of which extend through the tipping material and plug 
wrap. 
Typically, the tobacco rod has a length which ranges from about 50 mm to 
about 85 mm, a circumference of about 17 mm to about 27 mm; and the 
wrapping material thereof is a conventional cigarette wrapping paper. 
Suitable cigarette wrapping papers are available as Reference Nos. 719, 
856, P-2540-49, P-2540-10A, P-2540-10B, P-2123-101, P-2123-102, 
P-2123-104, P-2123-106, P-2123-107, P-2123-108, P-2123-109, P-2123-111, 
P-2123-112 and P-2123-114 from Kimberly-Clark Corp., or as Ecusta 
Experimental Nos. TOD 04620, TOD 04621, TOD 04706, TOD 04982 and TOD 05024 
from Ecusta Corp. The wrapping papers can be electrostatically perforated. 
If desired a dual wrapper system can be employed. The tobacco rods and the 
resulting cigarettes can be manufactured in any known configuration using 
known cigarette making techniques and equipment. 
Typically, the filter element has a length which ranges from about 20 mm to 
about 35 mm and a circumference of about 17 mm to about 27 mm. The filter 
material can be any suitable material such as cellulose acetate, 
polypropylene, tobacco paper material, or the like. Filter materials 
having compositions or characteristics so as to exhibit low nicotine 
filtration efficiencies can be employed. The plug wrap typically is a 
conventional paper plug wrap, and can be either air permeable or 
essentially air impermeable. However, if desired, a nonwrapped cellulose 
acetate filter element can be employed. The various filter elements 
suitable for use in this invention can be manufactured using known 
cigarette filter making techniques and equipment. 
Typically, the tipping material circumscribes the filter element and an 
adjacent region of the tobacco rod such that the tipping material extends 
about 3 mm to about 6 mm along the length of the tobacco rod. Typically, 
the tipping material is a conventional paper tipping material. The tipping 
material can have a porosity which can vary. For example, the tipping 
material can be essentially air impermeable, air permeable, or be treated 
(e.g., by mechanical or laser perforation techniques) so as to have a 
region of perforations, openings or vents, thereby providing a means for 
providing air dilution to the cigarette. The total surface area of the 
perforations and the positioning of the perforations along the periphery 
of the cigarette can be varied in order to control the performance 
characteristics of the cigarette. 
As used herein, the term "air dilution" is the ratio (generally expressed 
as a percentage) of the volume of air drawn through the air dilution means 
to the total volume of air and aerosol drawn through the cigarette and 
exiting the extreme mouthend portion of the cigarette. For air diluted or 
ventilated cigarettes of this invention, the amount of air dilution can 
vary. Preferably, the amount of air dilution for a cigarette is greater 
than about 20 percent, more preferably greater than about 30 percent. The 
upper limit of air dilution for a cigarette typically is less than about 
80 percent, more frequently less than about 60 percent. 
The smokable material employed in the manufacture of the tobacco rod can 
vary. For example, the tobacco material can be engineered in a processed 
form such as an extruded form (e.g., as a foamed extruded rod or extruded 
into a tubular shape), have the form of filler such as tobacco cut filler, 
or the like. Generally, the tobacco material of cigarettes has the form of 
cut filler. As used herein, the terms "filler" or "cut filler" are meant 
to include tobacco materials which have a form suitable for use in the 
manufacture of cigarette tobacco rods. As such, filler can include tobacco 
materials which are blended and are in a form ready for cigarette 
manufacture. The tobacco filler materials conveniently are employed in the 
form of strands or shreds as is common in conventional cigarette 
manufacture. For example, the tobacco cut filler material can be employed 
in the form of strands cut into widths ranging from about 1/10 inch to 
about 1/60 inch, preferably from about 1/25 inch to about 1/40 inch. 
Generally, such strands have lengths which range from about 1/4 inch to 
about 3 inches. 
Tobacco materials can be cased and top dressed as is conventionally 
performed during various stages of cigarette manufacture. For example, 
additives such as flavorants and humectants can be applied to the tobacco 
material as is commonly done when cigarettes are manufactured. Suitable 
additives include flavorants such as vanillin, cocoa, licorice, menthol, 
tobacco aroma oils, tobacco extracts, and the like. Such additives 
conveniently are applied to the smokable material as top dressing 
components, or otherwise blended with the smokable material. 
The majority of the filler material present in the smokable rod preferably 
is a tobacco material. However, the tobacco material can be blended with 
another smokable material, such as those smokable materials described in 
U.S. patent application Ser. No. 276,161, filed Nov. 23, 1988 and U.S. 
patent application Ser. No. 414,833 filed Sept. 29, 1989. Examples of 
suitable tobacco materials include flue-cured, Burley, Maryland or 
Oriental tobaccos; processed tobacco materials such as expanded tobaccos, 
processed tobacco stems, reconstituted tobacco materials or reconstituted 
tobacco materials having varying levels of endogenous and exogenous 
nicotine; or blends thereof. 
Tobacco material(s) having a naturally high nicotine content conveniently 
constitute at least a portion of the smokable filler material useful in 
manufacturing cigarettes of the present invention. Typically, such useful 
high nicotine content tobaccos or high nicotine content processed tobaccos 
have nicotine contents of above about 2.5 percent. The nicotine contents 
of high nicotine tobacco materials oftentimes are above about 3 percent, 
frequently above about 4 percent, and in certain circumstances above about 
5 percent. Generally, the nicotine content of tobacco materials useful in 
this invention does not exceed about 10 percent. 
The high nicotine content filler material can vary. For example, tobaccos 
designated by the U.S.D.A. as Type 35 (One Sucker), Type 36 (Green River) 
or Type 37 (Virginia Sun Cured) are common tobaccos having a naturally 
high nicotine content. A cultivar such as Nicotiana rustica often has a 
natural nicotine content in the range of about 6 percent to about 10 
percent. Additionally, also useful are upper stalk leaves of commercial 
lines of flue-cured tobacco (designated by the U.S.D.A. as Types 11-14) 
and Burley tobacco (designated by the U.S.D.A. as Type 31). The natural 
nicotine content of many tobaccos can depend upon the agronomic conditions 
under which the tobaccos are grown as well as the particular genetic line 
of the tobacco. 
Processed tobacco materials can be employed. Such processed tobaccos can be 
provided using tobacco reconstitution-type processes. For example, 
materials can be manufactured using extrusion, cast sheet, fourdrinier or 
paper making processes. Raw materials used in manufacturing processed 
tobaccos can include those high nicotine tobaccos described hereinbefore; 
or various types of tobacco extracts can be employed in the manufacturing 
steps of the processed tobaccos. Alternatively, processed tobaccos can be 
manufactured under conditions suitable to provide products having various 
nicotine levels. If desired, nicotine can be incorporated into the 
expansion solvents used to provide a volume expanded processed tobacco 
material having a high nicotine content. Typical expansion processes are 
described in U.S. Pat. No. Re. 30,693 to Fredrickson and U.S. Pat. No. Re. 
3,524,452 to Moser et al. Also, processed tobacco materials include 
tobaccos or tobacco materials mixed, blended or otherwise treated with 
tobacco extracts, spray dried tobacco extracts or tobacco aroma oils. 
Methods for providing suitable tobacco extracts are set forth in U.S. Pat. 
No. 4,506,682 to Mueller and European Patent Application Nos. 326,370 and 
338,831. As such, the processed tobacco materials have high nicotine 
contents upon completion of the processing steps involved in their 
preparation or manufacture, and prior to their use in the manufacture of 
cigarettes. 
High nicotine tobacco(s) and/or high nicotine processed tobacco(s) can be 
employed as the tobacco material of the cigarette, as the components of 
cigarette blends or as portions of the components of cigarette blends. For 
example, the high nicotine tobaccos and/or high nicotine processed tobacco 
materials can be blended with other smokable materials having nicotine 
contents of less than about 2 percent. Typically, the so-called "American 
blends" having high nicotine contents (i.e., total blend nicotine contents 
above about 2 percent) are desirable for cigarette manufacture. Typical 
total nicotine contents of the tobacco material or blends of materials 
from which tobacco rods for cigarettes of this invention are manufactured 
are greater than about 2.25 percent, generally greater than 2.5 percent, 
often greater than about 3 percent, frequently greater than about 3.5 
percent, and in certain circumstances greater than about 4 percent. 
The inorganic salt of the organic acid can vary, but includes an inorganic 
salt of levulinic acid. The alkali metal and alkali earth metal salts of 
inorganic acids are particularly preferred. Examples of suitable salts are 
calcium levulinate, magnesium levulinate, sodium levulinate and potassium 
levulinate. Such salts can be provided using the techniques described by 
Cox et al in U.S. Pat. No. 2,033,909. Alternatively, such salts can be 
obtained from Pfaltz and Bauer, Inc., Waterbury, Conn. or K&K 
Laboratories, Div. of ICN Biochemicals, Inc., Cleveland, Ohio. 
Other organic acids and/or inorganic salts of organic acids can be employed 
according to the present invention in addition to the inorganic salt of 
levulinic acid. For example, salts of malic, citric, oxalic, malonic, 
succinic, ascorbic, tartaric and fumaric acids can be contacted with the 
smokable material of cigarettes of the present invention. The calcium, 
magnesium, sodium and potassium salts of such acids are particularly 
preferred. As such acids commonly are flavoring agents for smokable 
materials, the acids themselves and/or the inorganic salts of such acids 
are added to the smokable material of cigarettes of the present invention 
in amounts which depend upon the flavor threshold of the particular acid 
and the specific flavor characteristics of the acid. For example, it may 
be desirable to employ certain organic acids and inorganic salts of such 
organic acids at low enough levels, in order that the cigarette does not 
exhibit taste or aroma characteristics which can be perceived as being 
chemical, metallic, bitter, pungent or soapy in nature, or as being 
dissonant to the general organoleptic characteristics associated with 
tobacco smoke. 
The inorganic salt of the organic acid can be contacted with the smokable 
material in a variety of ways. For example, the inorganic salt of the 
organic acid can be applied to the smokable filler material or combined 
with some or all of the smokable filler material. If desired, the 
inorganic salts of organic acids can be incorporated into processed 
tobacco filler materials during the manufacture of such materials. For 
example, such additives can be mixed with tobacco extracts (e.g., tobacco 
essences or tobacco aroma oils), and the resulting tobacco extracts can be 
blended with, mixed with, or otherwise used to treat smokable materials. 
Typically, the inorganic salt of the organic acid is incorporated in the 
cigarette by admixing that additive with at least a portion of the 
smokable material. The manner or process for applying the salt additive to 
the smokable material can vary depending upon whether the additive is 
applied diluted in liquid form, or upon the positioning of the additive 
with respect to the smokable material. For example, the additive can be 
applied using syringes or techniques such as spraying, casing, 
electrostatic deposition, impregnation, garniture injection, spray drying, 
inclusion and encapsulation techniques, and the like. 
Suitable liquid carriers for the salt additives include water, ethanol, 
glycerol, propylene glycol, and the like, as well as combinations thereof. 
One or more organic acids and/or salts provided from nicotine and an 
organic acid can be incorporated into the cigarette. The use of nicotine 
salts can provide for a cigarette having a relatively high nicotine 
content as well as provide the organic acid additive. The nicotine salts 
can be incorporated into cigarettes which include smokable materials 
having a wide range of nicotine contents. In addition, organic acids in 
acid form (e.g., levulinic acid) can be incorporated into the cigarette. 
See, U.S. Pat. No. 4,836,224 to Lawson et al, which is incorporated herein 
by reference. 
Various amounts of the particular inorganic salts of the organic acid can 
be employed within the cigarettes of the present invention. The amount of 
salt additive incorporated within a cigarette can vary so as to provide a 
cigarette yielding acceptable tobacco taste, strength and satisfaction 
upon smoking. Generally, the amount of inorganic salt of the organic acid 
combined with the smokable material is such that the anionic moiety of the 
salt is greater than about 0.01 percent, frequently about 0.1 percent, 
preferably above about 0.5 percent, more preferably above about 0.75 
percent, and most preferably above about 1 percent, based on the dry 
weight of the smokable filler material within the cigarette. Although the 
amount of inorganic salt of the organic acid which is combined with the 
smokable material is such that the anionic moiety of the salt can exceed 
about 1.5 percent; the amount of such additive typically is less than 
about 5 percent, and is more typically less than about 3 percent, based on 
the dry weight of the smokable filler material. 
The cigarettes of this invention preferably provide a mainstream smoke 
exhibiting a pH which is essentially equal to or less than that of a 
similar cigarette absent of the organic acid salt additive incorporated 
therein. In certain circumstances, an amount of organic acid salt additive 
is incorporated into a cigarette in order to reduce the pH of the 
mainstream smoke during use thereof. Mainstream smoke is that smoke which 
is drawn through the cigarette and into the mouth of the smoker. For 
example, for a cigarette having smokable tobacco material contained in a 
circumscribing outer wrapping material, the mainstream smoke is the 
mainstream tobacco smoke which includes the combustion and/or pyrolysis 
products of tobacco material. 
In referring to a reduction in the pH of mainstream smoke, it is meant a 
lowering of the average pH of the mainstream smoke per particular 
cigarette. Such reduction is provided by the addition of an effective 
amount of the additive. Typically, the reduction in pH is a lowering of 
the pH by more than about 0.03 pH unit; preferably by more than about 0.08 
pH unit. One technique for determining the pH of whole smoke is described 
by Harris et al in Tobacco Science, Vol. XXI, p. 58 (1977). Another 
technique for determining the pH of whole smoke is described by 
Sensabaugh, Jr. et al in Tobacco Science, Vol. XI, p. 25 (1967). 
Cigarettes of the present invention generally yield from about 0.2 mg to 
about 3.5 mg, frequently from about 0.3 mg to about 2.5 mg, more 
frequently from about 0.4 mg to about 1.5 mg of nicotine when smoked under 
FTC conditions. Typically, FTC "tar" to FTC nicotine ratios for cigarettes 
of the present invention are less than about 12, generally less than about 
10, frequently less than about 8, and in certain instances less than about 
6. Typically, the FTC "tar" to FTC nicotine ratios of a cigarette having 
an organic acid salt incorported therein can be lowered by up to about 80 
percent of that ratio of similar cigarette not having the salt additive 
incorporated therein. 
The following examples are provided in order to further illustrate the 
invention but should not be construed as limiting the scope thereof. 
Unless otherwise noted, all parts and percentages are by weight. 
EXAMPLE 1 
Cigarettes having lengths of about 84 mm and circumferences of about 24.85 
mm have tobacco rod lengths of 57 mm and filter element lengths of 27 mm. 
The tobacco rod includes a charge of tobacco cut filler weighing about 
0.67 g contained in a circumscribing cigarette paper wrap which is sold 
commercially as 856 Cigarette Paper by Ecusta Corp. The filter element is 
manufactured using conventional cigarette filter making technology from 
cellulose acetate tow (2.7 denier per filament, 48,000 total denier) and 
circumscribing non-air permeable paper plug wrap. The tobacco rod and 
filter element are aligned in an abutting, end-to-end relationship and 
secured together using a non-air permeable tipping paper. The tipping 
paper is adhesively secured to the filter element and the adjacent portion 
of the tobacco rod. The tipping material circumscribes the length of the 
filter element and about 3 mm of the length of the tobacco rod. Cigarettes 
so described are manufactured using a Pilot Cigarette Maker from 
Hauni-Werke Korber & Co. KG. 
The filler material employed in providing the tobacco rod is in the form of 
strands cut at about 32 cuts per inch. The initial filler material 
includes a blend of about 30 percent Burley tobacco cut filler, about 40 
percent flue-cured tobacco cut filler, and about 30 percent of a blend of 
65 parts volume expanded flue-cured tobacco cut filler and 35 parts volume 
expanded Burley tobacco cut filler. The blend has an aqueous casing of 
glycerin and flavors applied thereto. The blend has a nicotine content of 
about 2.5 percent, a moisture content of about 12 percent, and a glycerin 
content of about 1.6 percent. 
Sodium levulinate is contacted with the smokable material of the 
cigarettes. As such, a metal salt of levulinic acid is added as such to at 
least a portion of the smokable material of the cigarette. In particular, 
7.8 micrograms of a solution of 10 parts sodium levulinate in 90 parts 
water is injected into a cigarette so as to provide a cigarette having 
about 0.1 percent levulinate moiety therein. Such a cigarette is 
designated as Sample No. 1. Sample No. 2 is provided by injecting 15.5 
micrograms of a solution of 25 parts sodium levulinate in 75 parts water 
into a cigarette such that the cigarette has about 0.5 percent levulinate 
moiety therein. Sample No. 3 is provided by injecting 31.1 micrograms of a 
solution of 25 parts sodium levulinate in 75 parts water into a cigarette 
such that the cigarette has about 1 percent levulinate moiety therein. 
Another cigarette is not contacted with sodium levulinate, is employed for 
comparison purposes, and is designated as Sample No. C-- 1. 
The various cigarettes are smoked under FTC conditions. In particular, the 
tobacco cut filler material within the paper wrapper is burned to yield 
smoke. Data concerning (i) FTC "tar," FTC nicotine and FTC carbon 
monoxide, (ii) puff count, and (iii) data concerning the pH of the tobacco 
itself and mainstream smoke, for Sample Nos. 1-3 and C--1 are presented in 
Table I. 
TABLE I 
______________________________________ 
FTC FTC.sup.2 
FTC.sup.2 
Sam- Puff.sup.1 
CO.sup.2 Nicotine 
"Tar" Smoke.sup.3 
Tobacco.sup.4 
ple Count (mg) (mg) (mg) pH pH 
______________________________________ 
1 8.2 13.1 1.29 12.7 6.73 5.33 
2 8.6 13.7 1.36 13.3 6.67 5.30 
3 8.6 13.8 1.37 13.4 6.55 5.28 
C-1* 8.5 13.6 1.29 13.1 6.82 5.25 
______________________________________ 
*Not an example of the invention. 
.sup.1 Puff count is the average number of puffs per cigarette provided 
under FTC smoking conditions. 
.sup.2 FTC smoking conditions consist of 2 seconds of puffing (35 ml tota 
volume) separated by 58 seconds of smolder. 
.sup.3 Smoke pH is the average smoke pH for the mainstream smoke of 20 
cigarettes as determined using techniques described by Harris et al in 
Tobacco Science, Vol. XXI, p. 58 (1977). 
.sup.4 Tobacco pH is determined using techniques described by Bacot in 
USDA Tech. Bul., 1225 (1960). 
The data in Table I indicate that the smoke pH of the cigarettes decreases 
with increased application of sodium levulinate to the tobacco material, 
and the FTC "tar" to FTC nicotine ratios of the cigarettes show an overall 
decrease with increased application of sodium levulinate to the tobacco 
material. 
The various cigarettes are evaluated organoleptically. Cigarettes having 
increased application of sodium levulinate are judged as yielding 
mainstream smoke of (i) low harshness and bitterness, and (ii) desirably 
high smoothness and mildness. 
EXAMPLE 2 
The cigarettes containing calcium levulinate are by providing cigarettes in 
the manner described in Example 1, except that calcium levulinate additive 
is substituted for the sodium levulinate additive. 
The various cigarettes are evaluated organoleptically. Cigarettes having 
increased application of calcium levulinate are judged as yielding 
mainstream smoke of (i) low harshness and bitterness, and (ii) desirably 
high smoothness and mildness.