U.S. patent application number 09/909384 was filed with the patent office on 2002-06-20 for method of providing flavorful and aromatic compounds.
Invention is credited to Coleman, William Monroe III, Dominguez, Luis Mayan, Dube, Michael Francis.
Application Number | 20020074008 09/909384 |
Document ID | / |
Family ID | 22766563 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020074008 |
Kind Code |
A1 |
Coleman, William Monroe III ;
et al. |
June 20, 2002 |
Method of providing flavorful and aromatic compounds
Abstract
A method for providing flavorful and aromatic substances for use
in a smoking article is disclosed. In the method, a mixture is
provided including a reducing sugar source and a base catalyst. The
mixture has a selectively enriched content of at least one free
amino acid selected from the group consisting of serine, threonine,
valine, leucine, and isoleucine. The mixture is then subjected to
heat treatment for a time and under conditions sufficient to
provide a flavorful and aromatic composition.
Inventors: |
Coleman, William Monroe III;
(Winston-Salem, NC) ; Dube, Michael Francis;
(Winston-Salem, NC) ; Dominguez, Luis Mayan;
(Winston-Salem, NC) |
Correspondence
Address: |
GROVER M MYERS
R J REYNOLDS TOBACCO COMPANY
BOWMAN GRAY TECHNICAL CENTER
950 REYNOLDS BOULEVARD
WINSTON SALEM
NC
27102
US
|
Family ID: |
22766563 |
Appl. No.: |
09/909384 |
Filed: |
July 19, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09909384 |
Jul 19, 2001 |
|
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09206475 |
Dec 7, 1998 |
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Current U.S.
Class: |
131/310 ;
131/274; 131/290; 131/309 |
Current CPC
Class: |
Y10S 428/905 20130101;
A24B 15/306 20130101 |
Class at
Publication: |
131/310 ;
131/309; 131/290; 131/274 |
International
Class: |
A24B 015/00; A24B
015/42; A24B 015/28 |
Claims
That which is claimed:
1. A method for providing flavorful and aromatic substances for use
in a smoking article, comprising the steps of: providing a mixture
including a reducing sugar source and a base catalyst, said mixture
having a selectively enriched content of at least one free amino
acid selected from the group consisting of serine, threonine,
valine, leucine, and isoleucine; and subjecting said mixture to
heat treatment for a time and under conditions sufficient to
provide a flavorful and aromatic composition.
2. The method of claim 1, wherein said reducing sugar source
comprises a reducing sugar selected from the group consisting of
glucose, fructose, xylose, mannose, galactose, rhamnose, and
mixture thereof.
3. The method of claim 1, wherein said reducing sugar source is
high fructose corn syrup.
4. The method of claim 1, wherein said base catalyst is selected
from the group consisting of ammonium hydroxide, ammonium
orthophosphate, ammonium dihydrogen orthophosphate, diammonium
phosphate, ammonium citrate, ammounium carbonate, and ammonium
acetate.
5. The method of claim 1, wherein said base catalyst is diammonium
phosphate.
6. The method of claim 1, wherein said base catalyst is ammonium
hydroxide or ammonium carbonate.
7. The method of claim 1, wherein said mixture further comprises
licorice.
8. The method of claim 1, wherein said mixture further comprises
cocoa.
9. The method of claim 1, wherein said mixture comprises a
selectively enriched content of leucine.
10. The method of claim 1, wherein said mixture comprises a
selectively enriched content of threonine.
11. The method of claim 1, wherein said mixture comprises a
selectively enriched content of leucine and threonine.
12. The method of claim 1, wherein said mixture contains
cumulatively from about 1% to about 10% by weight of exogenous
amino acids selected from the group consisting of serine,
threonine, valine, leucine, and isolecuine based on the total
weight of the mixture.
13. The method of claim 1, wherein said mixture contains
cumulatively from about 4% by weight of exogenous amino acids
selected from the group consisting of serine, threonine, valine,
leucine, and isolecuine based on the total weight of the
mixture.
14. The method of claim 1, wherein said step of heat treatment is
conducted at a temperature of from about 175.degree. F. to about
350.degree. F.
15. The method of claim 1, wherein said step of heat treatment is
at a pressure of about 10 psig to about 1000 psig.
16. The method of claim 1 further comprising dissolving said
mixture in water to form an aqueous solution prior to said heat
treatment.
17. The method of claim 16, wherein the pH of the aqueous solution
is about 7.
18. A method for providing flavorful and aromatic substances for
use in a smoking article, comprising the steps of: providing a
mixture including a reducing sugar source, a base catalyst,
licorice, and coca, said mixture having a selectively enriched
content of at least one free amino acid selected from the group
consisting of serine, threonine, leucine, and isoleucine; and
subjecting the mixture to heat treatment at a temperature of from
about 175.degree. F. to about 380.degree. F. and at a pressure of
about 10 psig to about 1000 psig to provide a flavorful and
aromatic composition.
Description
FIELD OF INVENTION
[0001] The present invention relates to smoking articles such as
cigarettes, and in particular to process for providing a flavorful
and aromatic composition similar to those characteristics of
certain tobaccos.
BACKGROUND OF THE INVENTION
[0002] Popular smoking articles, such as cigarettes, have a
substantially rod shaped structure and include a charge of smokable
material such as strands or shreds of tobacco (e.g., cut filler)
surrounded by a paper wrapper thereby providing a so-called
"tobacco rod." Numerous popular cigarettes have cylindrical filter
elements aligned in an end-to-end relationship with the tobacco
rod. Typically, filter elements are constructed from fibrous
materials such as cellulose acetate, have a circumscribing plug
wrap, and are attached to the tobacco rod using tipping
material.
[0003] 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.
No. 4,708,151 to Shelar; U.S. Pat. No. 4,714,082 to Banerjee et
al.; U.S. Pat. No. 4,756,318 to Clearman et al.; and U.S. Pat. No.
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 mouth-end
piece. Such types of smoking articles provide natural tobacco
flavors to the smoker thereof by heating, rather than burning,
tobacco in various forms.
[0004] Flavor and aroma are important characteristics of smoking
articles. To improve the flavor and aroma in smoking articles,
flavorful and aromatic substances, including various natural
extracts, have been included in smoking articles. For example,
various processes for producing and using tobacco extracts, aroma
oils and concentrates are proposed in the U.S. Pat. No. 3,136,321
to Davis; U.S. Pat. No. 3,316,919 to Green; U.S. Pat. No. 3,424,171
to Rooker; U.S. Pat. No. 4,421,126 to Gellatly and U.S. Pat. No.
4,506,682 to Mueller and European Patent Publication No. 338,831 to
Clapp et al.
[0005] U.S. Pat. No. 5,413,122 to Shu issued on May 9, 1995
discloses making a flavorful and aromatic composition from
.beta.-hydroxy .alpha.-amino acids by contacting the amino acids
with a liquid having an aqueous character followed by heat
treatment in an enclosed environment to provide an aqueous solution
of volatile pyrazine flavorants. The ratio of liquid to amino acid
is 4:1 to 40:1. The resulting aqueous extract containing flavorful
pyrazines is then applied to smoking materials to provide flavor
and aroma in the smoking articles.
[0006] It has also been proposed to react sugars with amino acids
to produce desirable flavorants for smoking articles and foods. For
example, U.S. Pat. No. 3,478,015 discloses heating an amino acid
and a sugar in the presence of a polyhydric alcohol and using the
reaction product as a flavoring material.
[0007] U.S. Pat. No. 3,920,026 describes reacting the amino acid
valine with a sugar, other hydroxycarbonyl compound, or dicarbonyl
compound under heat treatment in a solvent such as glycerol or
propylene glycol and at a temperature of about 100.degree. C. to
about 200.degree. C. for about 0.5 to 5 hours. Optionally, a
catalyst such as a flavanoid or hydroxyacid is included in the
reaction. The reaction products can be used as flavorants in
tobacco compositions.
[0008] U.S. Pat. No. 4,306,577 discloses the production of
flavorants for smoking compositions by reacting reducing sugars and
selected amino acids in the presence of ammonium hydroxide and
optionally in the presence of an aldehyde in an essentially
solvent-free system at a temperature range of 90.degree. C. to
115.degree. C. The selected amino acids are those that have at
least two nitrogens such as glutamine, asparagine, lysine, and
arginine.
[0009] Similarly, U.S. Pat. No. Re. 32,095 discloses reacting a
reducing sugar with a source of ammonia in the presence of a trace
amount of certain amino acids at a temperature in the range of
about 90.degree. C. to about 115.degree. C. for about 5 to 15
minutes. The trace amino acids include aspartic acid, glutamic
acid, asparagine, and glutamine. The weight ratio of sugar to amino
acid is in the range of 200-300:1, and the weight ratio of sugar to
ammonia source is about 5-15:1.
[0010] Because of the volatile nature of flavorant and aroma
materials, they are often lost during use in cigarette
manufacturing steps. Also quantities of the flavorant and aroma
materials can diminish during the storage of the finished smoking
articles and it is often necessary to increase the initial content
of flavorants to compensate.
SUMMARY OF THE INVENTION
[0011] In accordance with the present invention, highly desirable
flavorful and aromatic substances, and particularly flavorful and
aromatic substances similar to and complementing those found in
smokable materials are generated by heating a mixture comprising a
reducing sugar source, a base catalyst, and an amino acid source
material having a selectively enriched content of at least one
amino acid selected from the group consisting of serine, threonine,
valine, leucine, and isolecine. The resulting composition of
flavorful and aromatic substances from the reaction includes a
substantial quantity of flavorful and aromatic pyrazines that have
low volatility and a low sensory threshold, i.e., powerful sensory
attributes at very low concentrations. Examples of such pyrazines
include, but are not limited to, methylcyclopentapyrazine,
cyclopentapyrazine, 2-methyl-5,6,7,8-tetrahydroquinoxaline,
dimethyl-isopropenyl pyrazine, dimethyl-propenyl pyrazine,
methyl-propenyl pyrazine, acetylpyrazine,
2,3,5-trimethyl-6-ethylpyrazine- , 2-methyl-3,5-dimethyl pyrazine,
2,6-diethyl pyrazine, trimethyl pyrazine, dimethyl pyrazine, etc.
These pyrazines are characterized by larger side chains than
flavorant pyrazines normally added to tobacco and/or generated in
substantial quantities during smoking. The larger side chains have
dual effects of decreasing the volatility of the flavorant while at
the same time increasing the flavor potency of the flavorant
substances typically by many orders of magnitude. Thus, less
quantities of the flavorant and aroma materials can be used in
smoking articles to provide a significantly greater enhancement of
flavor and aroma. At the same time, loss of the flavorants during
manufacturing and storage of the smoking articles is minimal.
[0012] Accordingly, in a first aspect, the present invention
relates to a method for providing flavorful and aromatic substances
for use in a smoking article. A mixture is provided comprising a
reducing sugar source, a base catalyst, and an amino acid source
having a selectively enriched content of at least one amino acid
selected from the group consisting of serine, threonine, valine,
leucine, and isoleucine. The mixture is then subjected to heat
treatment for a time and under conditions sufficient to provide
flavorful and aromatic substances.
[0013] The amino acid source can be a natural material containing
endogenous free amino acids, or a composition comprising extracted
or synthetic amino acids. The selective enrichment is the result of
the incorporation of one or more exogenous free amino acids
selected from the group consisting of serine, threonine, valine,
leucine, and isoleucine in the amino acid source. Preferably, the
mixture contains from about 0.1% to about 20%, more preferably from
about 0.5% to about 10%, and most preferably from about 3% to about
5% by weight, e.g., 4% by weight, cumulatively, of amino acids
selected from the group consisting of serine, threonine, valine,
leucine, and isoleucine based on the total weight of the
mixture.
[0014] Preferably, the mixture comprises materials normally used in
casing, such as licorice and cocoa that contain endogenous free
amino acids. More preferably, the mixture is formed by adding at
least one desirable amino acid and at least one base catalyst to a
conventional casing.
[0015] The mixture of reducing sugar source material, base catalyst
and the amino acid source having a selectively enriched content of
serine, threonine, leucine, and/or isoleucine is subjected to heat
treatment at a temperature of at least about 175.degree. F. to
provide a reaction material. Normally, the mixture is exposed to a
temperature sufficiently high and for a period of time sufficiently
long so as to provide a reaction material which exhibits a pleasant
flavor and aroma. However, it is preferable that the reaction
material is not exposed to such a high temperature for a
sufficiently long period of time so as to provide a reaction
material which exhibits a burnt, tarry, overly bitter or highly
metallic flavor.
[0016] In a preferred embodiment, the mixture is subjected to heat
treatment in an enclosed system under pressure. A pressure
controlled environment is provided by a pressure chamber or vessel
which provides, during heat treatment, containment of the
components of the mixture such that the lighter active compounds
formed (e.g., ammonia, acetaldehyde, carbonyls, etc.) are retained
within the vessel or chamber and can react to generate the
flavorful and aromatic substances. Heat treatment is preferably
conducted at a typical pressure range of from about 10 psig to
about 1,000 psig, normally from about 20 psig to about 500
psig.
[0017] The resulting flavorful and aromatic substances includes
pyrazine and pyridine components, having relatively low volatility
and potent flavors. The flavorful and aromatic 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 and aromatic substances are useful in those types of
smoking articles described in U.S. Pat. No. 4,708,151 to Shelar;
U.S. Pat. No. 4,714,082 to Banerjee et al.; U.S. Pat. No. 4,756,318
to Clearman et al.; and U.S. Pat. No. 4,793,365 to Sensabaugh et
al.; as well as European Patent Publication Nos. 212,234 and
277,519.
[0018] The flavorful and aromatic compositions also are useful as
cigarette filter additives. For example, the flavorful and aromatic
compositions can be incorporated into low-density polyethylene and
formed into strands, and then incorporated into cigarette filters
as described in U.S. Pat. No. 4,281,671 to Bynre et al. and U.S.
Pat. No. 4,826,905 to Green, Jr. et al. The flavorful and aromatic
compositions 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 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."
[0019] Because the aromatic flavorants generated in the method of
this invention have relatively low volatility, the loss of
flavorants and aroma materials during the manufacturing process and
storage of smoking articles is reduced. In addition, the aromatic
flavorants have a dramatically high flavor potency, i.e., powerful
sensory attributes at very low concentrations. As a result, smoking
articles with improved flavor and aroma can be made with the
aromatic flavorants. Further, the smoking articles can have more
consistent and uniform flavorful and aromatic characters.
[0020] The foregoing and other advantages and features of the
invention, and the manner in which the same are accomplished, will
become more readily apparent upon consideration of the following
detailed description of the invention taken in conjunction with the
accompanying examples, which illustrate preferred and exemplary
embodiments.
BRIEF DESCRIPTION OF THE FIGURES
[0021] FIG. 1 demonstrates the yield of pyrazines and furfurals
after heat treatment of a mixture according to the present
invention having a selectively enriched content of threonine and
leucine. This result is compared to the yield of pyrazines and
furfurals after heat treatment of a mixture which does not have a
selectively enriched content of any amino acids.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Suitable reducing sugars for use in the mixture include, but
are not limited to, glucose, fructose, mannose, galactose,
rhamnose, and mixtures thereof. The reducing sugar can be in a pure
form or in a crude form, e.g., high fructose corn syrup which
contains about 40% or more of fructose. Reducing sugars can also be
made by hydrolysis of disaccharides or polysaccharides as is well
known in the art.
[0023] Base catalysts as used in the present invention are
preferably ammonium compounds. Examples of such ammonium compounds
include but are not limited to ammonium hydroxide and ammonium
salts such as ammonium orthophosphate, ammonium dihydrogen
orthophosphate, diammonium monohydrogen orthophosphate, ammonium
citrate, ammonium acetate, ammonium carbonate and the like.
Preferably, ammonium hydroxide or ammonium carbonate are employed
when flavorants having elevated levels of pyrazine products are
desired. Diammonium phophosphate (DAP) is preferred when flavorants
having elevated levels of sugar thermal degradation products are
desired.
[0024] In preferred embodiments of this invention, the mixture also
contains natural biological materials or extracts of biological
materials, for example, cocoa, licorice, and the like. Typically,
suitable natural biological materials or extracts of biological
materials are those biological materials that are usually included
in casing. As is well known in the art, casing materials are used
as additives to enhance the flavors in smokable materials. In
cigarette manufacturing processes, casing materials are added to
tobacco leaf blends before cutting. Exemplary casing ingredients
that are commonly used in the art include, e.g., sugar, humectant
such as glycerine or a higher glycol, licorice, cocoa, etc. In a
preferred embodiment, the mixture is formed by adding a base
catalyst to a conventional casing, and then selectively enriching
the mixture with exogenous desirable amino acids as described in
detail below.
[0025] As is apparent to the skilled artisan, some of the
above-described materials may contain free amino acids. The term
"free amino acids" used herein refers to amino acids that are not
chemically modified and are not chemically bonded within proteins
or peptides or other molecules. Typically, many natural biological
materials or extracts of biological materials, such as licorice and
cocoa, may contain natural free amino acids. As is known in the
art, there are about twenty different types of free amino acids
existing in biological materials. The free amino acids naturally
existing in natural biological materials or extracts of biological
materials used in the mixture are referred to herein as
"endogenous" amino acids. The endogenous content of each amino acid
and the total endogenous content of all free amino acids in
different materials can be determined by various analytical methods
known in the art.
[0026] The mixture to be heated in this invention has a selectively
enriched content of at least one amino acid selected from the group
consisting of serine, threonine, valine, leucine, and isoleucine.
Preferably leucine and/or threonine is selectively enriched. More
preferably, leucine and threonine are both selectively
enriched.
[0027] The term "selectively enriched content" used herein means
that the content, i.e. quantity, of the above-described amino
acids, i.e., serine, threonine, valine, leucine, and isoleucine, in
the mixture of this invention is higher than the total endogenous
content of the same amino acids in the components of the mixture
that naturally contain free amino acids, e.g., natural biological
materials or extracts of biological. The term also means that the
enrichment of these amino acids are "selective," i.e., the relative
increase of the cumulative content by weight of these desirable
free amino acids in the mixture is greater than the relative
increase in the total cumulative content by weight of the remaining
free amino acids naturally present in the components of the mixture
that naturally contain free amino acids, e.g., natural biological
materials or extracts of biological materials. Preferably, the
relative increase of the cumulative content by weight of the amino
acids serine, threonine, valine, leucine, and/or isoleucine in the
mixture is at least 10% greater than the relative increase in the
total cumulative content by weight of the remaining free amino
acids naturally present in the components of the mixture that
naturally contain free amino acids, e.g., natural biological
materials or extracts of biological materials.
[0028] The selective enrichment can be achieved by adding in the
mixture "exogenous" desirable free amino acids, i.e., by providing
the above-described at least one amino acid selected from the group
consisting of serine, threonine, valine, leucine, and isoleucine in
the mixture in addition to the endogenous serine, threonine,
valine, leucine, and isoleucine in the components of the mixture
that naturally contain free amino acids, e.g., natural biological
materials or extracts of biological materials. Preferably,
exogenous amino acids are incorporated in their substantially pure
forms such as solid or solution. The exogenous amino acids may also
be premixed with one of the other components prior to incorporation
in the mixture. Preferably, only the content of the desirable amino
acids, i.e., serine, threonine valine, leucine, isoleucine, or
mixture thereof is increased although the content of the other free
amino acids can also be increased somewhat if desired.
[0029] When the mixture does not contain any component that
naturally have free amino acid, e.g., natural biological materials
or extracts of biological materials such as licorice or cocoa,
i.e., the mixture contains no endogenous free amino acids, any
addition of exogenous desirable amino acids, i.e., serine,
threonine, valine, leucine, and/or isoleucine to the mixture at a
chemically detectable amount is considered herein to be selectively
enrichment.
[0030] The total amount of all exogenous desirable amino acids,
i.e., serine, threonine, valine, leucine, isoleucine, in the
mixture can vary. Preferably, the mixture contains from about 0.1%
to about 20%, more preferably from about 0.5% to about 10%, and
even more preferably from about 3% to about 5% by weight, most
preferably about 4% cumulatively, by weight, of exogenous amino
acids selected from the group consisting of serine, threonine,
valine, leucine, and isoleucine, based on the total weight of the
mixture.
[0031] In the mixture, the content of the reducing sugar can be
from about 5% to about 50%, preferably from about 10% to about 45%,
and more preferably from about 30% to about 40% by weight of the
total weight of the mixture. The molar ratio between the base
catalyst and the reducing sugar in the mixture may range from about
0.01 to about 2.0, preferably from about 0.1 to about 1.0, more
preferably about 0.4 to 0.6, and most preferably is about 0.5 mole
base catalyst per mole of sugar. When licorice and cocoa are used,
their cumulative content may be up to about 30%, preferably from
about 2% to about 20%, and more preferably from about 5% to about
10%.
[0032] The mixture can be in either a solid or liquid state.
Preferably, the mixture is dissolved in a liquid having an aqueous
character to form a solution prior to heat treatment. 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. Preferably a 0.5:1
to 40:1 ratio of liquid to mixture is utilized in forming the
solution. When the mixture is dissolved in an aqueous solution, pH
optimization is optionally performed. Preferably, the pH of the
solution is adjusted to from about 5 to about 10, more preferably
to from about 6 to about 8, and most preferably to 7. Methods of
adjusting pH should be apparent to a skilled artisan.
[0033] The mixture, or solution thereof, comprising reducing sugar,
base catalyst and amino acid source which has a selectively
enriched content of serine, threonine valine, leucine and/or
isoleucine, is subjected to moderately high temperature treatment.
Typically, such treatment involves exposing the mixture to a
temperature above about 175.degree. F., preferably above about
200.degree. F., and more preferably above about 280.degree. F.
However, it is desirable to subject the amino acid to a temperature
below about 450.degree. F., more desirably below about 400.degree.
F., most preferably about 350.degree. F. or less, in order to avoid
an undesirable formation of components which are deleterious to the
taste characteristics of the flavorful and aromatic composition.
Most preferably the heat treatment is conducted at a temperature of
from about 280.degree. F. to about 350.degree. F.
[0034] The moderately high temperature treatment of the mixture 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).
[0035] The moderately high temperature treatment is preferably
performed in a pressure-controlled environment. Such an environment
is provided by enclosing the mixture 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 provide
enclosure or concealment of the mixture such that any volatile
flavor components generated are not lost or do not otherwise escape
during the moderately high temperature treatment step. Preferred
pressure vessels are equipped with an external heating source.
Examples of vessels which provide a pressure controlled environment
include a high pressure autoclave from Berghof/America Inc. of
Concord, Calif. and 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 mixture 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.
Pressures experienced by the mixture typically exceed 100 psig
during the process of the present invention.
[0036] The amount of time that the mixture is subjected to the
moderately high temperature treatment can vary. Normally, the time
period is sufficient to heat the mixture at the desired temperature
for a period of at least about 10 minutes, preferably at least
about 20 minutes, more preferably at least about 30 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 the mixture subjected to heat treatment
so that the mixture 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 mixture experiences a relatively
uniform temperature throughout the treatment period. In particular,
it is highly desirable for the mixture to be heated uniformly
throughout as much as possible at the maximum temperature to which
the mixture is subjected.
[0037] The heat treatment of the mixture in the present invention
leads to the formation of highly desirable flavorful and aromatic
substances, and particularly flavorful and aromatic substances
similar to and complementing those found in smokable materials. The
resulting composition of flavorful and aromatic substances from the
reaction has a great proportion of pyrazines with large side
chains. These pyrazines have low volatility and low sensory
threshold, i.e., having powerful sensory attributes at very low
concentrations. Examples of such pyrazines include, but are not
limited to, methylcyclopentapyrazine, cyclopentapyrazine,
2-methyl-5,6,7,8-tetrahydroquinoxaline, dimethyl-isopropenyl
pyrazine, dimethyl-propenyl pyrazine, methyl-propenyl pyrazine,
acetylpyridine, 2,3,5-trimethyl-6-ethylpyrazine- ,
2-methyl-3,5-dimethyl pyrazine, diethylpyrazines,
trimethylpyrazines, dimethylpyrazines, etc.
[0038] The flavorful and aromatic composition thus generated is
particularly rich in pyrazines having 3 or more carbons in their
side chains. As shown in Table I, generally speaking, the more
complex side chains a pyrazine has, the higher odor strength and
the lower volatility the pyrazine exhibits. Therefore, the
increased content of pyrazines having larger side chains
significantly decreases the volatility and increases the flavor
potency of the flavorant substances. Thus, when the flavorant and
aroma materials are used in smoking articles, less quantities are
required and they do not diminish significantly during
manufacturing and storage of the smoking articles.
1 TABLE I No. of Odor Volatility, Pryazine Carbons Strength bp
.degree. C. 2-Methyl- 1 1 136 2-Ethyl- 2 10 150 2,3-Dimethyl- 2 24
2,5-Dimethyl- 2 33 155 2,6-Dimethyl- 2 60 154 2,3,5-Trimethyl- 3
150 171 2-Methyl-3-ethyl- 3 460 2-Methyl-5-ethyl- 3 600
2-Methyl-6-ethyl- 3 1200 2,3,5,6-Tetramethyl- 4 150 190
2,3-Diethyl- 4 240 2,5-Dimethyl- 4 3000 2,6-Dimethyl- 4 10,000
2-Ethyl-3,5- 4 60,000 dimethyl 2-Ethyl-3,6- 4 120,000 dimethyl-
[0039] The flavorful and aromatic composition can be used with
various components of smoking articles. The amount of flavorful and
aromatic composition employed per cigarette can vary. For example,
in a typical cigarette having about 0.6 to about 1 g/rod of smoking
material, about 10 to about 10.sup.5 ppm of the composition can be
used as top dressing or casing. Generally up to 5% of the
composition by dry weight, based on the dry weight of tobacco
materials, can be used in the cigarette.
[0040] Cigarettes can further include a filter element such as
positioned adjacent to one end of rod such that the filter element
is axially aligned with the rod in an end-to-end relation. Filter
elements have a substantially cylindrical shape, and the diameter
of the rod is substantially equal to the diameter of the filter
element. Preferably, the filter element abuts the rod. The ends of
the filter element are open to permit the passage of air and smoke
therethrough. The filter element comprises filter material which
optionally is overwrapped with circumscribing wrap material. The
filter material can be in intimate contact with the flavorful and
aromatic composition. Such a segment is referred to as a
"smoke-altering filter segment." Normally, prior to smoking the
cigarette, the smoke-altering filter segment includes at least
about 0.1 percent of the mixture, based on the weight of the filter
material. The filter material can be a conventional cigarette
filter material such as cellulose acetate, polypropylene, or the
like, and the filter element can have a fibrous character, a molded
shape, or other such configuration.
[0041] The composition can also be contacted with tobacco and
employed as a form of tobacco in smoking article manufacture. For
example, tobacco cut filler, as well as the types of smokable
materials described in commonly assigned U.S. Pat. No. 4,920,990 to
Lawrence et al., the disclosure of which is incorporated herein by
reference, can be coated or otherwise contacted with about 0.001 to
about 5 percent by weight of the flavorful and aromatic
composition, based on the weight of the particular smokable
material. Furthermore, the coated tobacco cut filler may be
combined with aerosol forming materials, and employed in the
manufacture of those smoking articles described in U.S. Pat. No.
4,708,151 to Shelar; U.S. Pat. No. 4,771,795 to White et al.; U.S.
Pat. No. 4,714,082 to Banerjee et al.; U.S. Pat. No. 4,756,318 to
Clearman et al.; and U.S. Pat. No. 4,793,365 to Sensabaugh et al.,
the disclosures of which are incorporated herein by reference, as
well as European Patent Publication Nos. 212,234 and 277,519. In
addition, the coated tobacco cut filler can be incorporated into
those smoking articles described in U.S. Pat. No. 5,074,321 to
Gentry et al. and European Patent Publication No. 280,990.
[0042] When the tobacco rod is burned during use of the smoking
article, the flavorful and aromatic composition exhibits an aroma
which can be characterized as pleasant, clean, sweet, floral,
woody, musk-like and fruity. The aroma provided by the composition
is such that the characteristic sidestream cigarette smoke aroma is
masked or overridden by those components. As such the flavorful and
aromatic composition provides for a reduction in the negative
attributes associated with the aroma of mainstream smoke.
[0043] The following example is provided in order to further
illustrate preferred aspects of the invention but should not be
construed as limiting the scope thereof. Unless otherwise noted,
all parts and percentages are by weight.
EXAMPLE I
[0044] 3.42 pounds of high fructose corn syrup (HFCS), 0.78 pounds
of cocoa powder, 0.69 pounds of licorice powder, 0.45 pounds of
DAP, 0.19 pounds of L-threonine, 0.19 pounds of L-Leucine and 7.28
pounds of water were placed in a 2-gallon sealed reactor. The
resultant aqueous solution was stirred and heated from room
temperature to 350.degree. F. over ten (10) minutes. The mixture
was stirred for an additional thirty (30) minutes at 350.degree. F.
The mixture was thereafter cooled to 140.degree. F. over a period
of twenty-six (26) minutes and was discharged from the reactor. The
pressure inside the reactor reached 480 psig at the end of the hold
period. The resultant product was recovered and labeled as "Casing
with Thr and Leu."
[0045] As a control experiment, 3.75 pounds of HFCS, 0.85 pounds of
cocoa powder, 0.75 pounds of licorice powder, 0.50 pounds of DAP
and 7.15 pounds of water were combined and heated under the same
regiment. The resultant product was recovered and labeled as
"Casing without Amino Acids."
[0046] Both cooked casings were analyzed for headspace volatiles
and amino sugars. A sample of the headspace was collected from each
of the resulting products and analyzed by dynamic headspace Purge
and Trap/Gas Chromatography/Mass Selective Detection/Flame
Ionization Detection (P&T/GC/MSD/FID) analyses using a
conventional Headspace Unit, TEKMAR (Cincinnati, Ohio, USA) LSC
2000 equipped with a TEKMAR 2016 heated sampling station. The
headspace sample was obtained and collected over a period of 20
minutes at a temperature of 70.degree. C. from a 0.2 g sample held
in a 25 ml sample tube that was swept with dry helium at a flow
rate of 40 ml/min and a pressure of 20 psig throughout the sampling
period. Then the headspace sample was analyzed by Gas
Chromatography/Mass Selective Detection/Flame Ionization Detection
as noted above. The general description of the Headspace analysis
can be found in W. Coleman et al. J. Chrom. Sci. 32:323 (1994). For
Casing without Amino Acids, the amount of total pyrazines was found
to be 50 .mu.g per g internal standard. (Cyclohexanone was used as
internal standard). For Casing with Thr and Leu, the amount of
total pyrazines was 190 .mu.g per g internal standard, indicating
approximately a 4-fold increase in the yield of pyrazines. Sugar
thermal degradation products as estimated by furfural and
5-methyl-furfural totaled 320 .mu.g per g internal standard for
Casing without Amino Acids, whereas only 180 .mu.g per g internal
standard of furfurals were observed in Casing with Thr and Leu.
These results are shown graphically in FIG. 1. Total amino sugars,
as measured by mannosamine, galactosamine and glucosamine were 8
.mu.g/ml for the Casing without Amino Acids and 14 .mu.g/ml for
Casing with Thr and Leu.
[0047] The cooked casings were applied to reconstituted tobacco
sheet at an application rate of 4 pounds per 1000 pounds of
tobacco. Cigarette rods were prepared from the reconstituted
tobaccos. Panelists who smoked the cigarettes reported significant
perceptual differences in the cooked casing products when compared
to a control.
EXAMPLE II
[0048] Experiments similar to those of Example I were also
performed with individual amino acid asparagine, serine, threonine,
leucine, isolecine, and valine respectively in lieu of the
combination of the two amino acids threonine and leucine used in
Example I. 0.19 pound of one of the above amino acids is used in
each experiment. In addition, the same control experiment as
described in Example I was also performed (Casing without Amino
Acids).
[0049] All casings were evaluated for pyrazines. The pyrazines were
identified using Autospme GC-mass spectrometry, a method similar to
headspace (see "Autospme-chiral-GC-MSD Analysis of Essential Oils"
by Coleman, Perfetti and Lawrence, J. Chrom.Sci. Vol. 36, Dec.
1998). Typical pyrazines observed in these casing are reported in
Table II. For Casing without Amino Acids and the casing with
asparagine, small-chain, volatile pyrazines were observed. However,
for the casing with serine, threonine, leucine, isoleucine, or
valine, many more pyrazine species were observed and many of them
were highly substituted. These highly substituted pyrazines
generally exhibit low volatility and high flavor potency.
2TABLE II AUTOSPME RESULTS FOR SPECIFIC PYRAZINES IN SELECTED
HEATED CASING FORMULATIONS PYRAZINE TYPE BASE + BASE + BASE + BASE
+ BASE + BASE + DETECTED VIA BASE + DAP + DAP + DAP + DAP + DAP +
DAP + AUTOSPME/GC/MSD DAP ASN SER THR LEU ILE VAL PYRAZINE X X X X
METHYL X X X X X X X 2,5-DIMETHYL X X X X X X X 2,6-DIMETHYL X X X
X X X X ETHYL X X X X X 2,3-DIMETHYL X X X X X X 2-ETHYL-6-METHYL X
X X X X X X 2-ETHYL-5-METHYL X X X X X X X TRIMETHYL X X X X X X X
VINYL X X X X PROPYL X X 2-METHYL-5(1- X METHYLETHYL)
2-METHYLPROPYL X X 2,6-DIETHYL X X X X X 3-ETHYL-2,5- X X X X X X
DIMETHYL 2-ETHYL-3,5- X X DIMETHYL 2,5-DIETHYL X X X 2,3-DIETHYL X
X 2,3-DIMETHYL-5- X ETHYL 2-ETHYL-3,5- X X DIMETHYL
2-VINYL-6-METHYL X X X X 2-VINYL-5-METHYL X X X 2,3,5-TRIMETHYL-6-
X ETHYL 2,6-DIMETHYL-3- X VINYL (TENT) 2-METHYL-6-PROPYL X X
2-METHYL-3-PROPYL X 2-METHYL-3-(2- X METHYLPROPYL) ISOMERS
TETRAMETHYL X X X 2-ETHENYL-6- X X X X METHYL + 3,5-
DIETHYL-2-METHYL 2,3-DIETHYL-5- X X X METHYL + 2,3-
DIETHYL-6-METHYL 2,5-DIMETHYL-3-(2- X X METHYLPROPYL) ISOMERS
3,5,6,-TRIMETHYL- X 2-(2-METHYLPROPYL) ISOMERS 2,3-DIMETHYL-3- X X
PROPYL 2,3-DIMETHYL-5- X PROPYL 2,6-DIMETHYL-6- PROPYL
2-METHYL-3-(1- X X PROPENYL) TENT 2-(2-METHYLBUTYL) X
2-(3-METHYLBUTYL) X 2-METHYL-3-(2- X METHYLBUTYL) ISOMERS
2-METHYL-3-(3- X METHYLBUTYL) ISOMERS 2-METHYL-6-(1- X X PROPENYL)
TENT 2,5-DIMETHYL-3-(2- X METHYLBUTYL) ISOMERS 2,5-DIMETHYL-3-(3- X
METHYLBUTYL) ISOMERS 2,5-DIMETHYL-6,7- X X DIHYDRO-5H- CYCLOPENTA
METHYLCYCLOPENTA X X X X DIMETHYL- X CYCLOPENTA 2,3,5-TRIMETHYL-6-
X (3-METHYLBUTYL) 2,5,6-TRIMETHYL-3- X (2-METHYLPROPYL) ISOMERS
CYCLOPENTA 2,5,6-TRIMETHYL-3- (2-METHYLBUTYL) ISOMERS
2,5,6-TRIMETHYL-3- (3-METHYLBUTYL) ISOMERS 2,5-DIMETHYL-3- X X
PROPENYL METHYLCYCLOHEXA X X X X DIMETHYLCYCLOHEXA X X X X
[0050] Although the foregoing invention has been described in some
detail by way of illustration and example for purposes of clarity
of understanding, it will be obvious that certain changes and
modifications may be practiced within the scope of the appended
claims.
[0051] All publications and patent applications mentioned in the
specification are indicative of the level of those skilled in the
art to which this invention pertains. All publications and patent
applications are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
* * * * *