Tobacco treatment process

Flavorful tobacco extracts are provided by subjecting a moist spray dried tobacco extract to heat treatment. The moist extract is contacted with a sugar and an amino acid, and exposed to a temperature above about 100.degree. C. in a pressure controlled vessel. Resulting flavorful extracts are useful as forms of tobacco in cigarettes and other smoking articles.

BACKGROUND OF THE INVENTION 
The present invention relates to flavorful forms of tobacco for cigarettes 
and other types of smoking articles, and in particular, to processes for 
providing such flavorful forms of tobacco. 
Popular smoking articles, such as cigarettes, have a substantially 
cylindrical rod shaped structure and include a charge of smokable 
material, such as shreds or strands of tobacco material (i.e., in cut 
filler form), surrounded by a paper wrapper, thereby forming a tobacco 
rod. 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 includes cellulose acetate tow 
circumscribed by plug wrap, and is attached to the tobacco rod using a 
circumscribing tipping material. Many cigarettes include processed tobacco 
materials and/or tobacco extracts in order to provide certain flavorful 
characteristics to those cigarettes. 
Many types of smoking products and improved smoking articles have been 
proposed through the years as improvements upon, or as alternatives to, 
the popular smoking articles. Recently, U.S. Pat. Nos. 4,708,151 to 
Shelar; 4,714,082 to Banerjee et al; 4,756,318 to Clearman et al; and 
4,793,365 to Sensabaugh, Jr. et al; and European Patent Publication Nos. 
212,234 and 277,519 propose cigarettes and pipes which comprise a fuel 
element, an aerosol generating means physically separate from the fuel 
element, and a separate mouthend piece. Such types of smoking articles 
provide natural tobacco flavors to the smoker thereof by heating, rather 
than burning, tobacco in various forms. As natural tobacco flavors are 
important components of smoking articles in order that such smoking 
articles can provide adequate tobacco taste and aroma, improved processes 
for providing natural tobacco flavor substances and flavorful forms of 
tobacco are desirable. 
It would be highly desirable to provide a process for efficiently and 
effectively producing flavorful forms of tobacco. 
SUMMARY OF THE INVENTION 
The present invention relates to a process for providing flavorful natural 
tobacco substances which are useful forms of tobacco for various types of 
cigarettes and other smoking articles. In particular, a tobacco extract is 
subjected to heat treatment (i.e., a moderately high temperature 
treatment) under conditions sufficient to alter the chemical nature (e.g., 
the flavor and aroma characteristics) of the extract. Normally, the 
tobacco extract is exposed to a temperature sufficiently high and for a 
period of time sufficiently long so as to provide an extract which does 
not exhibit a "green" or harsh flavor. However, it is preferable that the 
tobacco extract not be exposed to such a high temperature for a 
sufficiently long period of time so as to provide an extract which 
exhibits a burnt, tarry, overly bitter or highly metallic flavor. 
The tobacco extract is combined with an aqueous liquid and can be carried 
by a substrate during the time that the extract undergoes the moderately 
high temperature treatment. In addition, moist tobacco extract can be 
combined with an organic liquid (e.g., glycerin) prior to the time that 
the tobacco extract is subjected to the moderately high temperature 
treatment. Thus, for purposes of the present invention, it is convenient 
to refer to the heat treatment, or the moderately high temperature 
treatment, of a tobacco composition. For purposes of this invention, a 
tobacco composition can include (i) a tobacco extract and an aqueous 
liquid, (ii) a tobacco extract, an aqueous liquid, and a substrate which 
carries the extract and aqueous liquid, (iii) a tobacco extract, an 
aqueous liquid and an organic liquid, or (iv) a tobacco extract, an 
aqueous liquid, an organic liquid and a substrate for the extract and 
liquids. If desired, additives including at least one sugar and/or at 
least one amino acid can be incorporated into the tobacco composition. 
More particularly, the present invention relates to a process for treating 
natural tobacco substances by subjecting a tobacco extract (e.g., an 
aqueous tobacco extract) to exposure to a temperature above about 
100.degree. C. The tobacco extract has a moisture content of at least 
about 5 weight percent, preferably at least about 15 weight percent, when 
that extract is exposed to the moderately high temperature treatment; and 
the tobacco extract is subjected to such treatment while enclosed in a 
pressure controlled environment. In general, the pressure experienced by 
the extract is greater than ambient (i.e., atmospheric) pressure. For 
purposes of this invention, the term "moisture content" relates to the 
weight of the water within the tobacco composition relative to the total 
weight of the tobacco composition. The tobacco extract normally is 
subjected to such treatment in order that the entire extract is exposed to 
a temperature above about 100.degree. C. for at least about 10 minutes. 
The flavorful tobacco substances so provided are useful as forms of tobacco 
for smoking products. For example, such flavorful tobacco substances are 
useful as casing or top dressing components for tobacco laminae and cut 
filler, as well as for other smokable materials. Alternatively, such 
flavorful tobacco substances are useful as one form of tobacco employed in 
those types of smoking articles described in U.S. Pat. Nos. 4,708,151 to 
Shelar; 4,714,082 to Banerjee et al; 4,756,318 to Clearman et al; and 
4,793,365 to Sensabaugh et al; as well as European Patent Publication Nos. 
212,234 and 277,519. The flavorful tobacco substances also are useful as 
cigarette filter additives. For example, the flavorful tobacco substances 
can be incorporated into low density polyethylene and formed into strands, 
and then incorporated into cigarette filters as described in U.S. Pat. 
Nos. 4,281,671 to Bynre et al and 4,862,905 to Green, Jr. et al. The 
flavorful tobacco substances also are useful as cigarette wrapper 
additives; or as additives to the inner regions of cigarette packages 
(e.g., within a paper/foil laminate of a cigarette package or within a low 
density polyethylene film which is placed within a cigarette package) in 
order to provide a desirable cigarette aroma and "pack aroma.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, tobacco material 10 is contacted 15 with an extraction 
solvent 18 having an aqueous character. As such, various soluble 
components are extracted from the tobacco material 10 yielding an aqueous 
tobacco extract 21 and a water insoluble tobacco residue 23. The aqueous 
tobacco extract 21 is separated 26 from the insoluble residue 23 using 
centrifugation techniques, or the like. The extracted tobacco components 
are separated from the solvent by distillation techniques followed by 
spray drying techniques 28, or the like. The resulting isolated tobacco 
extract 31 is in a relatively low solvent form. The extract then is 
contacted 33 with a liquid having an aqueous character, such that a moist 
tobacco extract 35 is provided. The moist tobacco extract is subjected to 
a moderately high temperature treatment 38 in an enclosed, pressure 
controlled environment for a period of time sufficient to provide 
desirable flavor characteristics to the extract. The resulting 
heat-treated extract then is collected 43 for later use in the manufacture 
of cigarettes and other smoking articles. 
The tobacco materials useful herein can vary. Tobacco materials which are 
used are of a form such that, under extraction conditions, a portion 
thereof is soluble in (i.e., extracted by) an extraction solvent; and a 
portion thereof is insoluble in (i.e., not extracted by) that extraction 
solvent. Examples of suitable types of tobaccos include flue-cured, 
Burley, Maryland and Oriental tobaccos, as well as the rare or specialty 
tobaccos. The tobacco material generally has been aged, and can be in the 
form of laminae and/or stem, or can be in processed form. Tobacco waste 
materials and processing by-products such as fines, dust, scrap, stems and 
stalks can be employed. Unaged, uncured mature, or immature tobaccos also 
can be employed. The aforementioned tobacco materials can be processed 
separately, or as blends thereof. 
A tobacco extract can be provided in a number of ways. In particular, the 
tobacco material is subjected to extraction conditions with a suitable 
solvent to extract a sufficient amount of the desired components from the 
tobacco material. The manner in which the tobacco material is extracted, 
and the type of solvent employed, can vary. For example, the tobacco 
material can be extracted using organic solvents (e.g., hexane, methanol 
or ethanol), halocarbons and halogenated hydrocarbons, supercritical 
fluids (e.g., supercritical carbon dioxide and supercritical sulfur 
hexafluoride), and the like. Preferably, the tobacco extract is provided 
by extracting the tobacco material using a liquid having an aqueous 
character. Such a liquid consists primarily of water, normally greater 
than about 90 weight percent water, and can be essentially pure water in 
certain circumstances. For example, a solvent having an aqueous character 
can be distilled water, tap water, or the like. However, a solvent having 
an aqueous character can include water having substances such as pH 
buffers, pH adjusters, organic and inorganic salts, sugars, amino acids or 
surfactants incorporated therein. The solvent also can be a co-solvent 
mixture of water and minor amounts of one or more solvents which are 
miscible therewith. 
Methods for extracting components from tobacco materials, separating 
extracts from unextracted tobacco materials, and isolating tobacco 
extracts will be apparent to the skilled artisan. 
The tobacco extract can have various forms. For example, it is desirable to 
subject an aqueous extract to a spray drying, freeze drying, belt drying, 
flash drying, or other suitable solvent removal process in order to 
provide a tobacco extract in a substantially solvent-free form. As such, 
tobacco extracts can have the form of a paste, a viscous liquid, a powder, 
a granular solid, a gel, or the like. Tobacco extracts can be processed as 
described in European Patent Application Nos. 326,370 and 338,831. 
Typically, tobacco extracts are provided in the form of spray dried 
extracts, freeze dried extracts, tobacco essences, or the like. 
For purposes of this invention, spray drying is a one-step continuous 
process for removing a liquid from a solution and producing a dried 
particulate form of the extracted components within the solution by 
spraying a feed of the solution into a hot drying medium. Representative 
spray drying processes are described in U.S. Pat. No. 3,398,754 to Tughan 
and European Patent Application No. 326,370. For purposes of this 
invention, freeze drying is an indirect, batch or continuous process for 
removing the liquid from a solution and producing a dried form of the 
extracted components by freezing the solution and drying the solution in a 
frozen state through sublimation under high vacuum. A representative 
freeze drying process is described in U.S. Pat. No. 3,316,919 to Green. 
Methods and conditions for providing extracted materials in a solid form 
(e.g., as a powder) will be apparent to the skilled artisan. 
The extracted tobacco components can be provided at a predetermined solvent 
level (e.g., in a predetermined high moisture form) by evaporating the 
solvent from the mixture of solvent and extract. Vacuum distillation and 
thin film evaporation techniques are particularly preferred. 
The tobacco extract is in contact with an aqueous liquid in order to 
provide a moist extract. Certain tobacco extracts which are extracted 
using an aqueous liquid may have a significant moisture content, and do 
not require further addition of aqueous liquid thereto. The manner of 
contacting a low moisture content tobacco extract with the aqueous liquid 
can vary and is not particularly critical. Typically, the extract and 
liquid are mixed using stirring or agitation, and often employing gentle 
heating. 
The amount of water relative to the tobacco extract (i.e., the moisture 
content of the extract) can vary when the heat treatment step of the 
process of the present invention is performed. Typically, the moisture 
content of the extract is at least about 5 weight percent, normally at 
least about 15 weight percent, and frequently at least about 25 weight 
percent. Normally, the moisture content of the extract does not exceed 
about 90 weight percent, and frequently does not exceed about 80 weight 
percent. 
The moist tobacco extract can be contacted with a substrate. Preferred 
substrates are normally solid materials and are thermally stable at those 
temperatures experienced during the heat treatment steps of the present 
invention. Examples of suitable substrate materials include porous 
carbons, carbon fibers, carbon yarns, high surface area glass beads, 
aluminas, clays, and the like. Typical substrates are aluminas available 
as D-2 Sintered Alpha Alumina from W. R. Grace & Co. and carbon yarns 
available as Kynol Catalogue No. CFY-020Y-3 from American Kynol, Inc. 
Furthermore, the moist tobacco extract can be contacted with an organic 
liquid. Examples of organic liquids include polyhydric alcohols (e.g., 
glycerin and propylene glycol). 
The tobacco extract normally includes a wide variety of flavorful tobacco 
components. If desired, flavoring agents (e.g., cocoa, licorice, St. 
John's bread, spices, herbs, and the like) can be added to the tobacco 
extract. Certain amounts of sugars (e.g., fructose, sucrose, glucose, 
maltose) can be added to the tobacco extract. Certain amounts of amino 
acids and amino acid analogs (e.g., glutamine, asparagine, proline, 
alanine, cystine, aspartic acid, phenylalanine, glutamic acid) can be 
added to the tobacco extract. If desired, sugars as well as amino acids or 
amino acid analogs can be added to a tobacco extract. 
The tobacco composition is subjected to moderately high temperature 
treatment. Typically, such treatment involves exposing the tobacco 
composition to a temperature above about 100.degree. C., preferably above 
about 110.degree. C., and more preferably above about 120.degree. C. 
However, it is desirable to subject the tobacco composition to a 
temperature below about 250.degree. C., more desirably below about 
200.degree. C., in order to avoid an undesirable formation of components 
which are deleterious to the taste characteristics of the tobacco 
composition. 
The moderately high temperature treatment of the tobacco composition can be 
performed under an inert atmosphere. For example, nitrogen and argon gas 
can be employed in order to provide an inert atmosphere. However, the heat 
treatment can be conducted under ambient atmosphere (i.e., air). 
The moderately high temperature treatment is performed in a pressure 
controlled environment. Such an environment is provided by enclosing the 
tobacco composition in an air sealed vessel or chamber. Typically, a 
pressure controlled environment is provided using a pressure vessel or 
chamber which is capable of withstanding relatively high pressures. Such 
vessels or chambers (i) provide enclosure or concealment of the tobacco 
composition such that volatile flavor components of the tobacco extract 
are not lost or do not otherwise escape during the moderately high 
temperature treatment step, and (ii) provide for treatment of the tobacco 
composition at a temperature significantly above about 100.degree. C. 
Preferred pressure vessels are equipped with an external heating source. 
Examples of vessels which provide a pressure controlled environment 
include a Parr Reactor Model No. 4522 and a Parr Reactor Model No. 4552 
available from The Parr Instrument Co. Operation of such exemplary vessels 
will be apparent to the skilled artisan. Typical pressures experienced by 
the tobacco composition during the process of the present invention range 
from about 10 psig to about 1,000 psig, normally from about 20 psig to 
about 500 psig. 
The amount of time that the tobacco composition is subjected to the 
moderately high temperature treatment can vary. Normally, the time period 
is sufficient to heat an entire tobacco composition at the desired 
temperature for a period of at least about 10 minutes, preferably at least 
about 20 minutes. Normally, the time period is less than about 3 hours, 
preferably less than about 1 hour. However, it is desirable to control the 
time/temperature profile of tobacco compositions subjected to heat 
treatment so that each tobacco composition is not subjected to a 
particularly high temperature for a lengthy period of time. It is highly 
desirable to employ a pressure vessel design or a vessel equipped with an 
agitation mechanism such that the tobacco composition experiences a 
relatively uniform temperature throughout the treatment period. In 
particular, it is highly desirable for the entire tobacco composition to 
be heated uniformly throughout as much as possible at the maximum 
temperature to which the tobacco composition is subjected. 
Conditions provided during the process of the present invention most 
desirably are such that certain components of the tobacco extract undergo 
Maillard or Browning Reactions. Such reactions are reactions between (i) 
the amino substituents of amino acids, peptides, proteins or other 
nitrogen-containing compounds, and (ii) the carbonyl group of a sugar in 
the reducing form or other carboxyl-containing compounds. Such reactions 
result in a significant darkening of the tobacco extract, typically to an 
extremely dark brown color. Such reactions often result in a moist tobacco 
extract of increased viscosity, particularly when the extract is subjected 
to relatively high temperature treatment for a relatively long period of 
time. See, Maillard, Ana. Chim., Vol. 9, pp. 5 and 258 (1916); Hodge, J. 
Agric. Food Chem., Vol. 1, p. 928 (1953); Nursten, Food Chem., Vol. 6, p. 
263 (1981) and Waller et al, ACS Symp. Ser. (1983). 
After the tobacco composition has been subjected to the moderately high 
temperature treatment for the controlled period of time, the tobacco 
composition is collected. The tobacco composition is provided in various 
forms for use in the manufacture of smoking articles. For example, a 
heat-treated tobacco composition can be contacted with a liquid carrier 
such as glycerin, propylene glycol, ethanol, water, or the like, and 
employed as a form of tobacco in smoking article manufacture. Forms of 
heat-treated tobacco compositions can be applied directly to smokable 
materials. For example, tobacco cut filler, as well as the types of 
smokable materials described in U.S. Pat. application Ser. No. 276,161, 
filed Nov. 23, 1988, now U.S. Pat. No. 4,920,990 to Lawrence et al., can 
be blended with about 0.01 to about 10 weight percent of the heat-treated 
tobacco extract, based on the weight of the smokable material. 
Furthermore, the heat-treated tobacco composition having the form of 
substrate and tobacco extract can be dried, combined with other aerosol 
forming materials, and employed in the manufacture of those smoking 
articles described in U.S. Pat. Nos. 4,708,151 to Shelar; 4,771,795 to 
White et al; 4,714,082 to Banerjee et al; 4,756,318 to Clearman et al; and 
4,793,365 to Sensabaugh et al; as well as European Patent Publication Nos. 
212,234 and 277,519. In addition, the heat-treated tobacco compositions 
can be incorporated into those smoking articles described in U.S. Pat. 
application Ser. No. 414,833 filed Sept. 29, 1989 and European Patent 
Publication No. 280,990. 
The following examples are provided in order to further illustrate various 
embodiments of the invention but should not be construed as limiting the 
scope thereof. Unless otherwise noted, all parts and percentages are by 
weight. 
EXAMPLE 1 
An aged flue-cured tobacco in cut filler form is extracted in a stainless 
steel tank at a concentration of about 1 pound of tobacco per gallon of 
water. The extraction is conducted at ambient temperature (e.g., about 
20.degree. C.) while mechanically agitating the mixture centrifuged to 
remove essentially all suspended solids. The aqueous extract is 
concentrated in a thin film evaporator to a concentration of about 30 
percent dissolved solids. Thin film evaporation conditions are such that 
water is evaporated from the extract while loss of flavorful tobacco 
volatiles is minimized. The concentrated aqueous extract then is spray 
dried by continuously pumping the aqueous solution to an Anhydro Size No. 
1 spray dryer. The dried powder is collected at the outlet of the dryer. 
The inlet temperature of the spray dryer is about 215.degree. C., and the 
outlet temperature is about 82.degree. C. The spray dried material is a 
brown, powdery material, and has a moisture content of about 5 percent to 
about 6 percent. 
The spray dried extract is mixed with water. In particular, about 175 g of 
the extract is mixed with about 200 g of water. The resulting moist 
extract is contacted with about 50 g high fructose corn syrup and about 50 
g asparagine in a Parr Reactor Model No. 4522 equipped with a temperature 
control unit available as Parr No. 4842-PID from The Parr Instrument Co. 
As such, the resulting tobacco composition within the pressure vessel 
weighs about 475 g. The pressure vessel is equipped with a mechanical 
stirrer. The moist extract then is subjected to exposure to a maximum 
temperature of about 125.degree. C. for about 30 minutes at a pressure of 
about 30 psig. Then, the tobacco composition is removed from the pressure 
vessel. The tobacco composition exhibits an extremely dark brown color and 
a pleasant aroma. 
The heat-treated tobacco composition is employed as a tobacco component for 
a cigarette which heats, but does not burn tobacco. The cigarette employs 
a short, carbonaceous fuel element, a 38 mm long aluminum capsule filled 
with alpha alumina beads in a heat exchange relationship with the fuel 
element, a roll of volume expanded Burley tobacco roll surrounding the 
capsule, a pleated section of tobacco paper, and a low efficiency 
polypropylene web filter. Such a cigarette is described in Chemical and 
Biological Studies on New Cigarette Prototypes that Heat Instead of Burn 
Tobacco, R. J. Reynolds Tobacco Co., (1988). The alpha alumina beads are 
available as D-2 Sintered Alpha Alumina from W. R. Grace & Co. 
To the alpha alumina beads of the cigarette is applied the heat-treated 
tobacco composition in an amount of 1 part tobacco extract to 20 parts 
beads. The beads also carry glycerin. Then, 300 mg of the treated alpha 
alumina beads are incorporated into the aluminum capsule of the cigarette. 
EXAMPLE 2 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 200 g water. The resulting moist extract 
is contacted with about 50 g asparagine in the pressure vessel described 
in Example 1. The resulting tobacco composition then is subjected to 
exposure to a maximum temperature of about 110.degree. C. for about 30 
minutes at a pressure of about 15 psig. The tobacco composition then is 
removed from the pressure vessel. The tobacco composition exhibits an 
extremely dark brown color and a pleasant aroma. 
EXAMPLE 3 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular, about 135 g of 
the extract is mixed with about 154 g water. The resulting moist extract 
is contacted with 39 g asparagine in the pressure vessel described in 
Example 1. The resulting tobacco composition then is subjected to exposure 
to a maximum temperature of about 140.degree. C. for about 30 minutes at a 
pressure of about 75 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 4 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular about 175 g of 
the extract is mixed with about 200 g water in the pressure is subjected 
to exposure to a maximum temperature of about 110.degree. C. for about 30 
minutes at a pressure of about 30 psig. The tobacco composition then is 
removed from the pressure vessel. The tobacco composition exhibits an 
extremely dark brown color and a pleasant aroma. 
EXAMPLE 5 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular about 175 g of 
the extract is mixed with about 200 g water in the pressure vessel 
described in Example 1. The moist extract then is subjected to exposure to 
a maximum temperature of about 130.degree. C. for about 30 minutes at a 
pressure of about 60 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 6 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 200 g water. The resulting moist extract 
is contacted with about 50 g asparagine in the pressure vessel described 
in Example 1. The resulting tobacco composition then is subjected to 
exposure to a maximum temperature of about 130.degree. C. for about 30 
minutes at a pressure of about 70 psig. The tobacco composition then is 
removed from the pressure vessel. The tobacco composition exhibits an 
extremely dark brown color and a pleasant aroma. 
EXAMPLE 7 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 200 g water. The resulting moist extract 
is contacted with about 50 g asparagine in the pressure vessel described 
in Example 1. The tobacco composition then is subjected to exposure to a 
maximum temperature of about 110.degree. C. for about 30 minutes at a 
pressure of about 35 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 8 
Spray dried tobacco extract is provided as described in Example 1. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 200 g water. The resulting moist extract 
is contacted with about 50 g glutamine in the pressure vessel described in 
Example 1. The resulting tobacco composition then is subjected to exposure 
to a maximum temperature of about 130.degree. C. for about 30 minutes at a 
pressure of about 60 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 9 
Spray dried Burley tobacco extract is provided by extracting Burley tobacco 
in cut filler form using equipment and procedures generally as described 
in Example 1. The spray dried extract is contacted with water. In 
particular, about 175 g of the extract is mixed with about 200 g water. 
The resulting moist extract is contacted with about 50 g asparagine in the 
pressure vessel described in Example 1. The resulting tobacco composition 
then is subjected to exposure to a maximum temperature of about 
130.degree. C. for about 30 minutes at a pressure of about 60 psig. The 
tobacco composition then is removed from the pressure vessel. The tobacco 
composition exhibits an extremely dark brown color and a pleasant aroma. 
EXAMPLE 10 
Spray dried Burley tobacco extract is provided by extracting Burley tobacco 
in cut filler form using equipment and procedures generally as described 
in Example 1. The spray dried extract is contacted with water. In 
particular, about 175 g of the extract is mixed with about 200 g water. 
The resulting moist extract is contacted with about 50 g glutamine in the 
pressure vessel described in Example 1. The tobacco composition then is 
subjected to exposure to a maximum temperature of about 130.degree. C. for 
about 30 minutes at a pressure of about 60 psig. The tobacco composition 
then is removed from the pressure vessel. The tobacco composition exhibits 
an extremely dark brown color and a pleasant aroma. 
EXAMPLE 11 
Spray dried Burley tobacco extract is provided by extracting Burley tobacco 
in cut filler form using equipment and procedures generally as described 
in Example 1. The spray dried extract is contacted with water. In 
particular, about 175 g of the extract is mixed with about 200 g water in 
the pressure vessel described in Example 1. The moist extract then is 
subjected to exposure to a maximum temperature of about 130.degree. C. for 
about 30 minutes at a pressure of about 60 psig. The tobacco composition 
then is removed from the pressure vessel. The tobacco composition exhibits 
an extremely dark brown color and a pleasant aroma. 
EXAMPLE 12 
A spray dried tobacco extract is provided by extracting tobacco dust 
collected from a cigarette making machine using equipment generally as 
described in Example 1. The spray dried extract is contacted with water. 
In particular, about 175 g of the extract is mixed with about 200 g water. 
The resulting moist extract is contacted with about 50 g glutamine in the 
pressure vessel described in Example 1. The tobacco composition then is 
subjected to exposure to a maximum temperature of about 130.degree. C. for 
about 30 minutes at a pressure of about 30 psig. The tobacco composition 
then is removed from the pressure vessel. The tobacco composition exhibits 
an extremely dark brown color and a pleasant aroma. 
EXAMPLE 13 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with about 50 g asparagine in the pressure vessel described 
in Example 1. The tobacco composition then is subjected to exposure to a 
maximum temperature of about 180.degree. C. for about 30 minutes at a 
pressure of about 200 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 14 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water in the pressure vessel 
described in Example 1. The moist extract then is subjected to exposure to 
a maximum temperature of about 180.degree. C. for about 30 minutes at a 
pressure of about 160 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 15 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with about 50 g glutamine in the pressure vessel described in 
Example 1. The tobacco composition then is subjected to exposure to a 
maximum temperature of about 180.degree. C. for about 30 minutes at a 
pressure of about 180 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 16 
A mixture of about 60 parts water and about 40 parts glycerin is suspended 
with about 14.3 parts of the tobacco composition collected in Example 15. 
The resulting mixture is sprayed onto reconstituted tobacco strip such 
that the tobacco strip has about 0.5 percent heat treated tobacco extract 
applied thereto. The reconstituted tobacco strip is provided using a 
papermaking process, and includes about 42 parts calcium carbonate, about 
3.5 parts flax and about 54.5 parts of a blend of flue cured, Burley and 
Oriental tobaccos. The strip then is air dried to about a 13 percent 
moisture level, and is shredded at about 32 cuts per inch into cut filler 
form. The cut filler is used to manufacture a filter cigarette having a 
circumference of about 24.85 mm, a tobacco rod length of about 57 mm, and 
a filter element length of about 27 mm. The cut filler within each 
cigarette weighs about 803 mg, and the paper wrap of the tobacco rod is 
available as PP-2123 -1-114 from Kimberly-Clark Corp. The cigarette is 
smoked and yields mainstream smoke high in tobacco flavor. 
EXAMPLE 17 
A filter rod of about 120 mm length and about 24.55 mm circumference is 
provided. The filter material within each rod is a gathered web of 
nonwoven polypropylene sheet available as PP-100 from Kimberly-Clark Corp. 
The filter material within each rod weighs about 0.964 g. The gathered 
filter material circumscribed by a nonporous paper plug wrap available as 
Ref. No. 646 from Ecusta Corp. The filter rod is manufactured using the 
apparatus generally described in Example 1 of U.S. Pat. No. 4,807,809 to 
Pryor et al. 
The tobacco composition collected in Example 15 is applied to the filter 
rod. In particular, the tobacco composition is passed through a small 
funnel placed at one end of the filter rod, and is allowed to drain 
through the filter rod. The filter rod then is air dried to constant 
weight. The filter rod experiences a weight increase of about 58 mg. 
The filter rod is divided into filter segments of 21 mm length, and each 
segment is combined with a tobacco rod of 64 mm length to provide a filter 
cigarette. The cigarette is smoked and yields mainstream smoke high in 
tobacco flavor. 
EXAMPLE 18 
Paper/foil inner laminate liners for cigarette packages available as 
26035-01 004-7863 from The Archer Co. are contacted with the tobacco 
composition collected in Example 15 which has been diluted with water. The 
diluted tobacco composition includes about 5 parts water and about 1 part 
heat treated extract. The diluted tobacco composition is printed onto the 
paper side of the paper/foil liner. The liner is dried, and the liner 
experiences a weight increase of about 4 percent. The liners then are used 
to package cigarettes. The cigarettes packaged in such packages exhibit a 
highly pleasant tobacco rod aroma. The "pack aroma" of such packages is 
increased over similar packages not combined with the heat-treated 
composition. 
EXAMPLE 19 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with 50 g proline in the pressure vessel described in Example 
1. The tobacco composition then is subjected to exposure to a maximum 
temperature of about 180.degree. C. for about 30 minutes at a pressure of 
about 200 psig. The tobacco composition then is removed from the pressure 
vessel. The tobacco composition exhibits an extremely dark brown color and 
a pleasant aroma. 
EXAMPLE 20 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with about 50 g glutamic acid in the pressure vessel 
described in Example 1. The tobacco composition then is subjected to 
exposure to a maximum temperature of about 180.degree. C. for about 30 
minutes at a pressure of about 170 psig. The tobacco composition then is 
removed from the pressure vessel. The tobacco composition exhibits an 
extremely dark brown color. 
EXAMPLE 21 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with 50 g alanine in the pressure vessel described in Example 
1. The tobacco composition then is subjected to exposure to a maximum 
temperature of about 180.degree. C. for about 30 minutes at a pressure of 
about 180 psig. The tobacco composition then is removed from the pressure 
vessel. The tobacco composition exhibits an extremely dark brown color. 
EXAMPLE 22 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g water. The resulting moist extract 
is contacted with about 50 g phenylalanine in the pressure vessel 
described in Example 1. The tobacco composition then is subjected to 
exposure to a maximum temperature of about 180.degree. C. for about 30 
minutes at a pressure of about 200 psig. The tobacco composition then is 
removed from the pressure vessel. The tobacco composition exhibits an 
extremely dark brown color. 
EXAMPLE 23 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with glycerin. In particular, about 175 g 
of the extract is mixed with about 400 g glycerin. The extract so provided 
has a moisture content of above about 8 percent in the pressure vessel 
described in Example 1. The extract and glycerin are contacted with 50 g 
glutamine. The resulting tobacco composition then is subjected to exposure 
to a maximum temperature of about 180.degree. C. for about 30 minutes at a 
pressure of about 85 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma. 
EXAMPLE 24 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with water. In particular, about 175 g of 
the extract is mixed with about 400 g of water. The resulting moist 
extract is contacted with about 50 g aspartic acid in the pressure vessel 
described in Example 1. The resulting tobacco composition then is 
subjected to exposure to a maximum temperature of about 180.degree. C. for 
about 30 minutes at a pressure of about 245 psig. The tobacco composition 
then is removed from the pressure vessel. The tobacco composition exhibits 
an extremely dark brown color and a pleasant aroma. 
EXAMPLE 25 
Spray dried tobacco extract is provided as described in Example 12. The 
spray dried extract is contacted with glycerin. In particular, about 175 g 
of the extract is mixed with about 400 g glycerin. The resulting moist 
extract is contacted with about 50 g glycerin. The extract so provided has 
a moisture content of above about 8 percent. The extract and glycerin are 
contacted with about 50 g asparagine in the pressure vessel described in 
Example 1. The tobacco composition then is subjected to exposure to a 
maximum temperature of about 160.degree. C. for about 30 minutes at a 
pressure of about 80 psig. The tobacco composition then is removed from 
the pressure vessel. The tobacco composition exhibits an extremely dark 
brown color and a pleasant aroma.