U.S. patent application number 14/584296 was filed with the patent office on 2015-05-07 for thermal treatment process for tobacco materials.
The applicant listed for this patent is R. J. REYNOLDS TOBACCO COMPANY. Invention is credited to Paul Andrew Brinkley, Daniel Verdin Cantrell, Gong Chen, Anthony Richard Gerardi, Darrell Eugene Holton, JR., Serban C. Moldoveanu, John-Paul Mua, Frank Kelley St. Charles.
Application Number | 20150122271 14/584296 |
Document ID | / |
Family ID | 44509705 |
Filed Date | 2015-05-07 |
United States Patent
Application |
20150122271 |
Kind Code |
A1 |
Chen; Gong ; et al. |
May 7, 2015 |
THERMAL TREATMENT PROCESS FOR TOBACCO MATERIALS
Abstract
A method of preparing a tobacco material for use in a smoking
article is provided, including (i) mixing a tobacco material,
water, and an additive selected from the group consisting of
lysine, glycine, histidine, alanine, methionine, glutamic acid,
aspartic acid, proline, phenylalanine, valine, arginine, di- and
trivalent cations, asparaginase, saccharides, phenolic compounds,
reducing agents, compounds having a free thiol group, oxidizing
agents, oxidation catalysts, plant extracts, and combinations
thereof; (ii) heating the mixture; and (iii) incorporating the
heat-treated mixture into a smoking article as a smokable material.
A smoking article in the form of a cigarette is also provided that
includes a tobacco material pre-treated to inhibit reaction of
asparagine to form acrylamide in mainstream smoke. Upon smoking,
the smoking article is characterized by an acrylamide content of
mainstream smoke that is reduced relative to an untreated control
smoking article.
Inventors: |
Chen; Gong; (Clemmons,
NC) ; Gerardi; Anthony Richard; (Winston-Salem,
NC) ; Mua; John-Paul; (Advance, NC) ; Holton,
JR.; Darrell Eugene; (Clemmons, NC) ; Cantrell;
Daniel Verdin; (Lewisville, NC) ; St. Charles; Frank
Kelley; (Bowling Green, KY) ; Moldoveanu; Serban
C.; (Winston-Salem, NC) ; Brinkley; Paul Andrew;
(Winston-Salem, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
R. J. REYNOLDS TOBACCO COMPANY |
Winston-Salem |
NC |
US |
|
|
Family ID: |
44509705 |
Appl. No.: |
14/584296 |
Filed: |
December 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12855343 |
Aug 12, 2010 |
8944072 |
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14584296 |
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12476621 |
Jun 2, 2009 |
8434496 |
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12855343 |
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Current U.S.
Class: |
131/280 ;
131/300; 131/331; 131/347; 131/352 |
Current CPC
Class: |
A24B 15/30 20130101;
A24B 15/18 20130101; A24B 15/20 20130101; A24B 15/307 20130101;
A24B 3/12 20130101; A24B 13/00 20130101; A24D 3/00 20130101; A24B
15/306 20130101; A24C 5/00 20130101 |
Class at
Publication: |
131/280 ;
131/300; 131/347; 131/331; 131/352 |
International
Class: |
A24B 15/18 20060101
A24B015/18; A24D 3/00 20060101 A24D003/00; A24B 13/00 20060101
A24B013/00; A24C 5/00 20060101 A24C005/00 |
Claims
1-26. (canceled)
27. A method of preparing a tobacco product with reduced acrylamide
content, comprising: (i) mixing a tobacco material, water, and
asparaginase to form a moist tobacco mixture; (ii) heating the
moist tobacco mixture to form a heat-treated tobacco mixture,
wherein the pH of the moist tobacco mixture during the heating step
is less than about 10; and (iii) incorporating the heat-treated
tobacco mixture into a smoking article or into a smokeless tobacco
product.
28. The method of claim 27, wherein the asparaginase is present in
an amount of between about 100 ppm to about 10 weight percent,
based on the dry weight of the tobacco mixture.
29. The method of claim 27, wherein the asparaginase is present in
an amount of between about 100 ppm to about 1,000 ppm, based on the
dry weight of the tobacco mixture.
30. The method of claim 27, wherein the asparaginase is in the form
of an aqueous dispersion containing less than 10 weight percent
total organic solids.
31. The method of claim 27, wherein the number of asparaginase
units (ASNU) per gram of asparaginase composition is in the range
of 3000 to 4000.
32. The method of claim 27, wherein the heat-treated tobacco
mixture comprises less than about 2000 ppb of acrylamide.
33. The method of claim 32, wherein the heat-treated tobacco
mixture comprises less than about 1500 ppb of acrylamide.
34. The method of claim 33, wherein the heat-treated tobacco
mixture comprises less than about 1000 ppb of acrylamide.
35. The method of claim 27, wherein the temperature of the heating
step is greater than about 60.degree. C.
36. The method of claim 35, wherein the temperature of the heating
step is greater than about 100.degree. C.
37. The method of claim 27, wherein the heat-treated tobacco
mixture has a moisture content of no more than about 10 weight
percent.
38. The method of claim 27, wherein the heat-treated tobacco
mixture includes one or more further components selected from
flavorants, fillers, binders, pH adjusters, buffering agents,
colorants, disintegration aids, antioxidants, humectants, and
preservatives.
39. The method of claim 27, wherein the tobacco material is in a
shredded or particulate form or in the form of an extract.
40. The method of claim 27, wherein the heat-treated tobacco
mixture is incorporated into a cigarette.
41. The method of claim 40, wherein the cigarette comprises a rod
of smokable material circumscribed by a wrapping material and a
filter attached to the rod at one end thereof, wherein the smokable
material comprises the heat-treated tobacco mixture.
42. The method of claim 41, wherein the cigarette, upon smoking, is
characterized by an acrylamide content of mainstream smoke that is
reduced relative to an untreated control smoking article.
43. The method of claim 42, wherein the amount of acrylamide
reduction by weight in mainstream smoke is at least about 10
percent as compared to an untreated control smoking article.
44. The method of claim 43, wherein the amount of acrylamide
reduction in mainstream smoke is at least about 30 percent as
compared to an untreated control smoking article.
45. The method of claim 44, wherein the amount of acrylamide
reduction in mainstream smoke is at least about 50 percent as
compared to an untreated control smoking article.
46. The method of claim 45, wherein the amount of acrylamide
reduction in mainstream smoke is at least about 60 percent as
compared to an untreated control smoking article.
47. A smoking article in the form of a cigarette prepared according
to the method of claim 27.
48. A smokeless tobacco product prepared according to the method of
claim 27.
49. A tobacco product comprising a tobacco material pre-treated to
inhibit reaction of asparagine to form acrylamide, wherein the
pre-treatment comprises heating the tobacco material at a pH of
less than about 10 in the presence of water and asparaginase.
50. The tobacco product of claim 49, wherein the tobacco product is
in the form of a cigarette comprising a rod of smokable material
circumscribed by a wrapping material and a filter attached to the
rod at one end thereof, wherein the smokable material comprises the
pre-treated tobacco material.
51. The tobacco product of claim 50, wherein the cigarette, upon
smoking, is characterized by an acrylamide content of mainstream
smoke that is reduced relative to an untreated control smoking
article.
52. The tobacco product of claim 51, wherein the amount of
acrylamide reduction by weight in mainstream smoke is at least
about 10 percent as compared to an untreated control smoking
article.
53. The tobacco product of claim 52, wherein the amount of
acrylamide reduction in mainstream smoke is at least about 30
percent as compared to an untreated control smoking article.
54. The tobacco product of claim 53, wherein the amount of
acrylamide reduction in mainstream smoke is at least about 50
percent as compared to an untreated control smoking article.
55. The tobacco product of claim 54, wherein the amount of
acrylamide reduction in mainstream smoke is at least about 60
percent as compared to an untreated control smoking article.
56. The tobacco product of claim 49, wherein the tobacco product is
in the form of a smokeless tobacco product.
57. The method of claim 49, wherein the pre-treated tobacco
material comprises less than about 2000 ppb of acrylamide.
58. The method of claim 57, wherein the pre-treated tobacco
material comprises less than about 1500 ppb of acrylamide.
59. The method of claim 58, wherein the pre-treated tobacco
material comprises less than about 1000 ppb of acrylamide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 12/476,621, filed Jun. 2, 2009, which is
hereby incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The invention relates to processes for treatment of tobacco,
and in particular, to processes useful for the thermal treatment of
tobacco materials.
BACKGROUND OF THE INVENTION
[0003] Popular smoking articles, such as cigarettes, have a
substantially cylindrical rod shaped structure and include a
charge, roll or column of smokable material such as shredded
tobacco (e.g., in cut filler form) surrounded by a paper wrapper
thereby forming a so-called "tobacco rod." Normally, a cigarette
has a cylindrical filter element aligned in an end-to-end
relationship with the tobacco rod. Typically, a filter element
comprises plasticized cellulose acetate tow circumscribed by a
paper material known as "plug wrap." Certain cigarettes incorporate
a filter element having multiple segments, and one of those
segments can comprise activated charcoal particles. Typically, the
filter element is attached to one end of the tobacco rod using a
circumscribing wrapping material known as "tipping paper." It also
has become desirable to perforate the tipping material and plug
wrap, in order to provide dilution of drawn mainstream smoke with
ambient air. A cigarette is employed by a smoker by lighting one
end thereof and burning the tobacco rod. The smoker then receives
mainstream smoke into his/her mouth by drawing on the opposite end
(e.g., the filter end) of the cigarette.
[0004] The tobacco used for cigarette manufacture is typically used
in blended form. For example, certain popular tobacco blends,
commonly referred to as "American blends," comprise mixtures of
flue-cured tobacco, burley tobacco and Oriental tobacco, and in
many cases, certain processed tobaccos, such as reconstituted
tobacco and processed tobacco stems. The precise amount of each
type of tobacco within a tobacco blend used for the manufacture of
a particular cigarette brand varies from brand to brand. However,
for many tobacco blends, flue-cured tobacco makes up a relatively
large proportion of the blend, while Oriental tobacco makes up a
relatively small proportion of the blend. See, for example, Tobacco
Encyclopedia, Voges (Ed.) p. 44-45 (1984), Browne, The Design of
Cigarettes, 3.sup.rd Ed., p. 43 (1990) and Tobacco Production,
Chemistry and Technology, Davis et al. (Eds.) p. 346 (1999).
[0005] Tobacco also may be enjoyed in a so-called "smokeless" form.
Particularly popular smokeless tobacco products are employed by
inserting some form of processed tobacco or tobacco-containing
formulation into the mouth of the user. Various types of smokeless
tobacco products are set forth in U.S. Pat. No. 1,376,586 to
Schwartz; U.S. Pat. No. 3,696,917 to Levi; U.S. Pat. No. 4,513,756
to Pittman et al.; U.S. Pat. No. 4,528,993 to Sensabaugh, Jr. et
al.; U.S. Pat. No. 4,624,269 to Story et al.; U.S. Pat. No.
4,987,907 to Townsend; U.S. Pat. No. 5,092,352 to Sprinkle, III et
al.; and U.S. Pat. No. 5,387,416 to White et al.; US Pat. Appl.
Pub. Nos. 2005/0244521 to Strickland et al. and 2008/0196730 to
Engstrom et al.; PCT WO 04/095959 to Arnarp et al.; PCT WO
05/063060 to Atchley et al.; PCT WO 05/016036 to Bjorkholm; and PCT
WO 05/041699 to Quinter et al., each of which is incorporated
herein by reference. See, for example, the types of smokeless
tobacco formulations, ingredients, and processing methodologies set
forth in U.S. Pat. No. 6,953,040 to Atchley et al. and U.S. Pat.
No. 7,032,601 to Atchley et al., each of which is incorporated
herein by reference.
[0006] One type of smokeless tobacco product is referred to as
"snuff." Representative types of moist snuff products, commonly
referred to as "snus," are manufactured in Europe, particularly in
Sweden, by or through companies such as Swedish Match AB, Fiedler
& Lundgren AB, Gustavus A B, Skandinavisk Tobakskompagni A/S,
and Rocker Production AB. Snus products available in the U.S.A. are
marketed under the tradenames Camel Snus Frost, Camel Snus Original
and Camel Snus Spice by R. J. Reynolds Tobacco Company.
Representative smokeless tobacco products also are marketed under
the tradenames Oliver Twist by House of Oliver Twist A/S;
Copenhagen, Skoal, SkoalDry, Rooster, Red Seal, Husky, and Revel by
U.S. Smokeless Tobacco Co.; "taboka" by Philip Morris USA; and Levi
Garrett, Peachy, Taylor's Pride, Kodiak, Hawken Wintergreen,
Grizzly, Dental, Kentucky King, and Mammoth Cave by Conwood Sales
Co., L.P. See also, for example, Bryzgalov et al., 1N1800 Life
Cycle Assessment, Comparative Life Cycle Assessment of General
Loose and Portion Snus (2005). In addition, certain quality
standards associated with snus manufacture have been assembled as a
so-called GothiaTek standard.
[0007] Through the years, various treatment methods and additives
have been proposed for altering the overall character or nature of
tobacco materials utilized in tobacco compositions. For example,
additives or treatment processes are sometimes utilized in order to
alter the chemistry or sensory properties of the tobacco material,
or in the case of smokable tobacco materials, to alter the
chemistry or sensory properties of mainstream smoke generated by
smoking articles including the tobacco material. In some cases, a
heat treatment process can be used to impart a desired color or
visual character to the tobacco material, desired sensory
properties to the tobacco material, or a desired physical nature or
texture to the tobacco material.
[0008] In particular, the sensory attributes of cigarette smoke can
be enhanced by incorporating flavoring materials into various
components of a cigarette. See, Leffingwell et al., Tobacco
Flavoring for Smoking Products, R.J. Reynolds Tobacco Company
(1972). Exemplary flavoring additives include menthol and products
of Maillard reactions, such as pyrazines, aminosugars, and Amadori
compounds. Various processes for preparing flavorful and aromatic
compositions for use in tobacco compositions are set forth in U.S.
Pat. No. 3,424,171 to Rooker; U.S. Pat. No. 3,476,118 to Luttich;
U.S. Pat. No. 4,150,677 to Osborne, Jr. et al.; U.S. Pat. No.
4,986,286 to Roberts et al.; U.S. Pat. No. 5,074,319 to White et
al.; U.S. Pat. No. 5,099,862 to White et al.; U.S. Pat. No.
5,235,992 to Sensabaugh, Jr.; U.S. Pat. No. 6,298,858 to Coleman,
III et al.; U.S. Pat. No. 6,325,860 to Coleman, III et al.; U.S.
Pat. No. 6,428,624 to Coleman, III et al.; U.S. Pat. No. 6,440,223
to Dube et al.; U.S. Pat. No. 6,499,489 to Coleman, III; and U.S.
Pat. No. 6,591,841 to White et al.; US Pat. Appl. Publication No.
2004/0173228 to Coleman, III; and U.S. application Ser. No.
12/191,751 to Coleman, III et al., filed Aug. 14, 2008, each of
which is incorporated herein by reference. Such processes often
include the application of heat to a tobacco material, which can
result in reactions that form certain byproducts.
[0009] The sensory attributes of smokeless tobacco can also be
enhanced by incorporation of certain flavoring materials. See, for
example, US Pat. Appl. Pub. Nos. 2002/0162562 to Williams;
2002/0162563 to Williams; 2003/0070687 to Atchley et al.;
2004/0020503 to Williams, 2005/0178398 to Breslin et al.;
2006/0191548 to Strickland et al.; 2007/0062549 to Holton, Jr. et
al.; 2007/0186941 to Holton, Jr. et al.; 2007/0186942 to Strickland
et al.; 2008/0029110 to Dube et al.; 2008/0029116 to Robinson et
al.; 2008/0029117 to Mua et al.; 2008/0173317 to Robinson et al.;
and 2008/0209586 to Neilsen et al., each of which is incorporated
herein by reference.
[0010] It would be desirable in the art to provide further methods
for altering the character and nature of tobacco (and tobacco
compositions and formulations) useful in smoking articles or
smokeless tobacco products.
SUMMARY OF THE INVENTION
[0011] The present invention provides a method of thermally
processing a tobacco material in the presence of an additive
adapted to alter the nature and character of the tobacco material,
such as by changing the sensory properties of the tobacco material
or changing the chemistry of the resulting heat-treated product. In
particular, certain additives are used to inhibit the formation of
reaction products resulting from the reaction of asparagine with
certain reducing sugars. More specifically, certain embodiments of
the invention provide tobacco products, including smoking articles
and smokeless tobacco compositions, that include tobacco material
pre-treated with an additive in order to inhibit reaction of
asparagine to form acrylamide upon heating or burning of the
tobacco material. Exemplary additives include amino acids,
compositions incorporating di- and trivalent cations, asparaginase,
certain non-reducing saccharides, certain reducing agents, phenolic
compounds (e.g., compounds having at least one phenolic
functionality), certain compounds having at least one free thiol
group or functionality, oxidizing agents, oxidation catalysts,
natural plant extracts (e.g., rosemary extract), and combinations
thereof. The invention is also based in part on the recognition
that certain heat treatment parameters can be controlled in order
to change the chemistry of the resulting heat-treated product, such
as maintaining the pH below about 8 during heating steps or
reducing the heating time or temperature.
[0012] In one aspect, the invention provides a method of thermally
processing a tobacco material for use in a smoking article or a
smokeless tobacco composition, comprising: (i) mixing tobacco
material with water and an additive capable of inhibiting reaction
of asparagine to form acrylamide upon heating or burning of the
tobacco material (e.g., an additive selected from the group
consisting of lysine, glycine, histidine, alanine, methionine,
glutamic acid, aspartic acid, proline, phenylalanine, valine,
arginine, compositions incorporating di- and trivalent cations,
asparaginase, certain non-reducing saccharides, certain reducing
agents, phenolic compounds, certain compounds having at least one
free thiol group or functionality, oxidizing agents, oxidation
catalysts, natural plant extracts (e.g., rosemary extract), and
combinations thereof), to form a moist tobacco mixture; (ii)
heating the moist tobacco mixture at a temperature of at least
about 60.degree. C. (e.g., at least about 100.degree. C.) to form a
heat-treated tobacco mixture; and (iii) incorporating the
heat-treated tobacco mixture into a tobacco product, such as a
smoking article or a smokeless tobacco product For example, the
heat-treated tobacco mixture could be used as a smokable material
within a smoking article such as a cigarette.
[0013] Preferred additives include lysine, glycine, histidine,
alanine, methionine, glutamic acid, aspartic acid, proline,
phenylalanine, valine, arginine, cysteine, asparaginase, oxidizing
agents (e.g., hydrogen peroxide or ozone), oxidation catalysts
(e.g., titanium dioxide), and combinations thereof. The amount of
the additive can vary, but is typically between about 100 ppm to
about 10 dry weight percent. The heat-treated tobacco mixture often
can include further components, such as flavorants, fillers,
binders, pH adjusters, buffering agents, colorants, disintegration
aids, antioxidants, humectants, and preservatives.
[0014] In another aspect, the invention provides a method of
preparing a smokeless tobacco product, comprising: (i) mixing
tobacco material; ingredients such as water, flavorant, binder, and
filler; and an additive selected from the group consisting of
lysine, glycine, histidine, alanine, methionine, glutamic acid,
aspartic acid, proline, phenylalanine, valine, arginine,
compositions incorporating di- and trivalent cations, asparaginase,
certain non-reducing saccharides, certain reducing agents, phenolic
compounds, certain compounds having at least one free thiol group
or functionality, oxidizing agents, oxidation catalysts, natural
plant extracts (e.g., rosemary extract), and combinations thereof,
to form a moist tobacco mixture; (ii) forming the moist tobacco
mixture into a desired product shape; and (iii) heating the moist
tobacco mixture at a temperature of at least about 60.degree. C.
(e.g., at least about 100.degree. C.) so as to provide a heat
treatment process step and hence produce a dried smokeless tobacco
product.
[0015] The heat treatment process can be characterized by the
change in moisture content of the tobacco composition. For example,
the moist tobacco mixture can have a moisture content of greater
than about 20 weight percent, based on the total weight of the
tobacco mixture; and the dried smokeless tobacco product can have a
moisture content of less than about 10 weight percent. The heat
treatment process can also be characterized by the pH during the
heating step, which can be less than about 10.0, less than about
8.0, less than about 7.0, or less than about 6.5.
[0016] The desired product shape can have the form of a pill,
tablet, sphere, sheet, coin, cube, bead, ovoid, obloid, bean,
stick, or rod. Such product shapes can be formed in a variety of
manners using equipment such as moving belts, nips, extruders,
granulation devices, compaction devices, and the like.
Alternatively, the treated tobacco material can be used in a
particulate form.
[0017] In one embodiment, the method of the invention includes (i)
mixing about 10 to about 60 dry weight percent of a tobacco
material, up to about 50 dry weight percent of one or more fillers,
about 10 to about 85 weight percent water, about 5 to about 30 dry
weight percent of one or more binders, up to about 10 dry weight
percent of one or more flavorants, and at least about 0.1 dry
weight percent of an additive selected from the group consisting of
lysine, glycine, histidine, alanine, methionine, glutamic acid,
aspartic acid, proline, phenylalanine, valine, arginine,
compositions incorporating di- and trivalent cations, asparaginase,
certain non-reducing saccharides, certain reducing agents, phenolic
compounds, certain compounds having at least one free thiol group
or functionality, oxidizing agents, oxidation catalysts, natural
plant extracts (e.g., rosemary extract), and combinations thereof,
to form a moist tobacco mixture; (ii) forming the moist tobacco
mixture into a desired product shape; and (iii) heating the moist
tobacco mixture at a temperature of at least about 100.degree. C.
for a heat processing time (e.g., at least about 15 minutes) in
order to produce a dried smokeless tobacco product having a
moisture content of no more than about 10 weight percent.
[0018] In yet another aspect, the invention provides a heat-treated
tobacco composition prepared according to the method of the
invention. Such heat-treated compositions can be characterized by
low acrylamide content, such as an acrylamide content of less than
about 2000 ppb, less than about 1500 ppb, less than about 1000 ppb,
less than about 900 ppb, less than about 800 ppb, less than about
700 ppb, less than about 600 ppb, less than about 500 ppb, less
than about 400 ppb, or less than about 300 ppb.
[0019] In one embodiment, the invention provides a heat-treated
smokeless tobacco composition comprising a tobacco material, water,
a flavorant, a binder, and a filler, wherein the heat-treated
smokeless tobacco composition has an acrylamide content of no more
than about 1500 ppb. The heat-treated smokeless tobacco composition
can have a preformed shape selected from the group consisting of
pill, tablet, sphere, sheet, coin, cube, bead, ovoid, obloid, bean,
stick, and rod. The moisture content of the heat-treated smokeless
tobacco composition is typically no more than about 10 weight
percent.
[0020] The amounts of each ingredient of the heat-treated smokeless
tobacco composition can vary, but in one embodiment, the
composition comprises about 20 to about 60 dry weight percent of a
tobacco material, about 20 to about 50 dry weight percent of one or
more fillers, about 5 to about 20 dry weight percent of one or more
binders, and about 1 to about 10 dry weight percent of one or more
flavorants.
[0021] In embodiments wherein the treated tobacco of the invention
is utilized in smoking articles, the tobacco can be in the form of
cut filler. The tobacco material can also be in blended form.
[0022] A smoking article containing the treated tobacco of the
invention can be characterized, upon smoking, by an acrylamide
content of mainstream smoke that is reduced relative to an
untreated control smoking article. The amount of acrylamide
reduction in mainstream smoke is typically at least about 10
percent as compared to an untreated control smoking article,
meaning the amount by weight of acrylamide in mainstream smoke
produced by a smoking article of the invention is at least about 10
percent less than the amount of acrylamide produced by an untreated
control smoking article smoked under the same conditions (e.g.,
under ISO conditions). The amount of reduction is often at least
about 30 percent, more often at least about 50 percent, and most
often at least about 60 percent.
[0023] In one aspect, the invention provides a smoking article in
the form of a cigarette comprising a rod of smokable material
circumscribed by a wrapping material and a filter attached to the
rod at one end thereof, wherein the smokable material comprises a
tobacco material pre-treated to inhibit reaction of asparagine to
form acrylamide in mainstream smoke. The pre-treatment can comprise
the treatment process described herein, such as heating the tobacco
material in the presence of an additive of the types discussed
herein.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention now will be described more fully
hereinafter. This invention may, however, be embodied in many
different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the invention to those skilled in
the art. As used in this specification and the claims, the singular
forms "a," "an," and "the" include plural referents unless the
context clearly dictates otherwise. Reference to "dry weight
percent" or "dry weight basis" refers to weight on the basis of dry
ingredients (i.e., all ingredients except water).
[0025] The invention provides a heat-treated tobacco composition
and a method for preparing a heat-treated tobacco composition. As
used herein, the term "heat-treated tobacco composition" refers to
a composition comprising a tobacco material that has been thermally
processed at an elevated temperature, such as a temperature of at
least about 60.degree. C., more typically at least about
100.degree. C., for a time sufficient to alter the character or
nature of the tobacco composition, such as at least about 10
minutes. In some cases, the heat treatment process alters the
chemistry or sensory characteristics (e.g., taste and aroma) of the
tobacco composition. The heat treatment process of the invention
can be a modified version of conventional tobacco treatment
processes, such as processes adapted to form flavorful and aromatic
compounds (e.g., Maillard reaction products), processes adapted for
pasteurization of tobacco compositions, processes for preparing
tobacco casing products, reconstituted tobacco processes (e.g.,
cast sheet and paper-making reconstituted tobacco processes),
tobacco extraction processes, reordering processes, toasting
processes, steam treatments, and drying processes.
[0026] The heat-treated tobacco compositions of the invention can
be used as an additive for a smoking article (e.g., as part of the
smokable blend or as an additive to the filter or wrapping paper of
the smoking article) or as a smokeless tobacco composition, such as
loose moist snuff, loose dry snuff, chewing tobacco, pelletized
tobacco pieces, extruded or formed tobacco strips, pieces, rods, or
sticks, finely divided ground powders, finely divided or milled
agglomerates of powdered pieces and components, flake-like pieces,
molded processed tobacco pieces, pieces of tobacco-containing gum,
rolls of tape-like films, readily water-dissolvable or
water-dispersible films or strips, or capsule-like materials.
[0027] Tobaccos used in the tobacco compositions of the invention
may vary. The tobaccos may include types of tobaccos such as
flue-cured tobacco, burley tobacco, sun-cured tobacco (e.g.,
Oriental tobacco or Indian Kurnool), Maryland tobacco, dark
tobacco, dark-fired tobacco, dark air cured (e.g., passanda,
cubano, jatin and bezuki tobaccos) or light air cured (e.g., North
Wisconsin and galpoa tobaccos), and Rustica tobaccos, as well as
other rare or specialty tobaccos or even green or uncured tobaccos.
Descriptions of various types of tobaccos, growing practices,
harvesting practices and curing practices are set forth in Tobacco
Production, Chemistry and Technology, Davis et al. (Eds.) (1999),
which is incorporated herein by reference. See, also, the types of
tobaccos that are set forth in U.S. Pat. No. 4,660,577 to
Sensabaugh, Jr. et al.; U.S. Pat. No. 5,387,416 to White et al.;
and U.S. Pat. No. 6,730,832 to Dominguez et al., each of which is
incorporated herein by reference. Most preferably, the tobacco
materials are those that have been appropriately cured and aged.
Especially preferred techniques and conditions for curing
flue-cured tobacco are set forth in Nestor et al., Beitrage
Tabakforsch. Int., 20 (2003) 467-475 and U.S. Pat. No. 6,895,974 to
Peele, which are incorporated herein by reference. Representative
techniques and conditions for air curing tobacco are set forth in
Roton et al., Beitrage Tabakforsch. Int., 21 (2005) 305-320 and
Staaf et al., Beitrage Tabakforsch. Int., 21 (2005) 321-330, which
are incorporated herein by reference. Certain types of unusual or
rare tobaccos can be sun cured. Manners and methods for improving
the smoking quality of Oriental tobaccos are set forth in U.S. Pat.
No. 7,025,066 to Lawson et al., which is incorporated herein by
reference. Representative Oriental tobaccos include katerini,
prelip, komotini, xanthi and yambol tobaccos. Tobacco compositions
including dark air cured tobacco are set forth in US Patent Appl.
Pub. No. 2008/0245377 to Marshall et al., which is incorporated
herein by reference.
[0028] In one embodiment, the tobacco material, or at least some
portion thereof, is selected so as to have a naturally low level of
asparagine. A representative range of asparagine content in certain
tobacco lamina typically can range from about 0.2 to about 0.7 dry
weight percent. Certain representative stem tobacco materials
typically contain lower levels of asparagine, such as about 0.1 to
about 0.3 dry weight percent. Representative tobacco materials in
blended forms used in smoking articles or smokeless tobacco
products typically possess an asparagine content of about 0.1 to
about 0.4 dry weight percent.
[0029] Tobacco compositions used in the present invention, such as
tobacco compositions intended to be used in a smokeless form, may
incorporate a single type of tobacco (e.g., in a so-called
"straight grade" form.). For example, the tobacco within a tobacco
composition may be composed solely of flue-cured tobacco (e.g., all
of the tobacco may be composed, or derived from, either flue-cured
tobacco lamina or a mixture of flue-cured tobacco lamina and
flue-cured tobacco stem). The tobacco within a tobacco composition
also may have a so-called "blended" form. For example, the tobacco
within a tobacco composition of the present invention may include a
mixture of parts or pieces of flue-cured, burley (e.g., Malawi
burley tobacco) and Oriental tobaccos (e.g., as tobacco composed
of, or derived from, tobacco lamina, or a mixture of tobacco lamina
and tobacco stem). For example, a representative blend may
incorporate about 30 to about 70 parts burley tobacco (e.g.,
lamina, or lamina and stem), and about 30 to about 70 parts flue
cured tobacco (e.g., stem, lamina, or lamina and stem) on a dry
weight basis. Other exemplary tobacco blends incorporate about 75
parts flue-cured tobacco, about 15 parts burley tobacco, and about
10 parts Oriental tobacco; or about 65 parts flue-cured tobacco,
about 25 parts burley tobacco, and about 10 parts Oriental tobacco;
or about 65 parts flue-cured tobacco, about 10 parts burley
tobacco, and about 25 parts Oriental tobacco; on a dry weight
basis. Other exemplary tobacco blends incorporate about 20 to about
30 parts Oriental tobacco and about 70 to about 80 parts flue-cured
tobacco.
[0030] The tobacco material can have the form of processed tobacco
parts or pieces, cured and aged tobacco in essentially natural
lamina or stem form, a tobacco extract, extracted tobacco pulp
(e.g., using water as a solvent), or a mixture of the foregoing
(e.g., a mixture that combines extracted tobacco pulp with
granulated cured and aged natural tobacco lamina). In some
embodiments, it is desirable to thoroughly wash the tobacco
material in water in order to remove some of the asparagine within
the tobacco.
[0031] The tobacco that is used for the tobacco product most
preferably includes tobacco lamina, or tobacco lamina and stem
mixture. Tobacco mixtures incorporating a predominant amount of
tobacco lamina, relative to tobacco stem, are preferred. Most
preferably, the tobacco lamina and stem are used in an unextracted
form, that is, such that the extractable portion (e.g., the water
soluble portion) is present within the unextractable portion (e.g.,
the tobacco pulp) in a manner comparable to that of natural tobacco
provided in a cured and aged form. Portions of the tobaccos within
the tobacco product may have processed forms, such as processed
tobacco stems (e.g., cut-rolled stems, cut-rolled-expanded stems or
cut-puffed stems), or volume expanded tobacco (e.g., puffed
tobacco, such as dry ice expanded tobacco (DIET)). See, for
example, the tobacco expansion processes set forth in U.S. Pat. No.
4,340,073 to de la Burde et al.; U.S. Pat. No. 5,259,403 to Guy et
al.; and U.S. Pat. No. 5,908,032 to Poindexter, et al.; and US
Patent Appl. Pub. No. 2004/0182404 to Poindexter, et al., all of
which are incorporated by reference. In addition, the tobacco
product optionally may incorporate tobacco that has been fermented.
See, also, the types of tobacco processing techniques set forth in
PCT WO 05/063060 to Atchley et al., which is incorporated herein by
reference.
[0032] The tobacco used in the present invention is typically
provided in a shredded, ground, granulated, fine particulate, or
powder form. Most preferably, the tobacco is employed in the form
of parts or pieces that have an average particle size less than
that of the parts or pieces of shredded tobacco used in so-called
"fine cut" tobacco products. Typically, the very finely divided
tobacco particles or pieces are sized to pass through a screen of
about 18 Tyler mesh, generally are sized to pass a screen of about
20 Tyler mesh, often are sized to pass through a screen of about 50
Tyler mesh, frequently are sized to pass through a screen of about
60 Tyler mesh, may even be sized to pass through a screen of 100
Tyler mesh, and further may be sized so as to pass through a screen
of 200 Tyler mesh. If desired, air classification equipment may be
used to ensure that small sized tobacco particles of the desired
sizes, or range of sizes, may be collected. In one embodiment, the
tobacco material is in particulate form sized to pass through an 18
Tyler mesh, but not through a 60 Tyler mesh. If desired,
differently sized pieces of granulated tobacco may be mixed
together. Typically, the very finely divided tobacco particles or
pieces suitable for snus products have a particle size greater than
-8 Tyler mesh, often -8 to +100 Tyler mesh, frequently -18 to +60
Tyler mesh.
[0033] The manner by which the tobacco is provided in a finely
divided or powder type of form may vary. Preferably, tobacco parts
or pieces are comminuted, ground or pulverized into a powder type
of form using equipment and techniques for grinding, milling, or
the like. Most preferably, the tobacco is relatively dry in form
during grinding or milling, using equipment such as hammer mills,
cutter heads, air control mills, or the like. For example, tobacco
parts or pieces may be ground or milled when the moisture content
thereof is less than about 15 weight percent to less than about 5
weight percent.
[0034] Tobacco extracts are useful as components of the tobacco
composition. Extracts can be used in solid form (e.g., spray-dried
or freeze-dried form), in liquid form, in semi-solid form, or the
like. Exemplary tobacco extracts and extraction techniques are set
forth, for example, in U.S. Pat. No. 4,150,677 to Osborne, Jr. et
al.; U.S. Pat. No. 4,967,771 to Fagg et al.; U.S. Pat. No.
5,005,593 to Fagg et al.; U.S. Pat. No. 5,148,819 to Fagg; and U.S.
Pat. No. 5,435,325 to Clapp et al., all of which are incorporated
by reference herein. Various tobacco extraction and reconstitution
methodologies are set forth in U.S. Pat. No. 5,065,775 to Fagg;
U.S. Pat. No. 5,360,022 to Newton; and U.S. Pat. No. 5,131,414 to
Fagg, all of which are incorporated by reference herein. See also,
the tobacco extract treatment methodologies set forth in U.S. Pat.
No. 5,131,415 to Munoz et al. and U.S. Pat. No. 5,318,050 to
Gonzalez-Parra, both of which are incorporated by reference
herein.
[0035] Suitable known reconstituted tobacco processing techniques,
such as paper-making techniques or casting-type processes, can be
employed in conjunction with the process of the invention. See, for
example, the types of paper-making processes set forth in U.S. Pat.
No. 3,398,754 to Tughan; U.S. Pat. No. 3,847,164 to Mattina; U.S.
Pat. No. 4,131,117 to Kite; U.S. Pat. No. 4,270,552 to Jenkins;
U.S. Pat. No. 4,308,877 to Mattina; U.S. Pat. No. 4,341,228 to
Keritsis; U.S. Pat. No. 4,421,126 to Gellatly; U.S. Pat. No.
4,706,692 to Gellatly; U.S. Pat. No. 4,962,774 to Thomasson; U.S.
Pat. No. 4,941,484 to Clapp; U.S. Pat. No. 4,987,906 to Young; U.S.
Pat. No. 5,056,537 to Brown; U.S. Pat. No. 5,143,097 to Sohn; U.S.
Pat. No. 5,159,942 to Brinkley et al.; U.S. Pat. No. 5,325,877 to
Young; U.S. Pat. No. 5,445,169 to Brinkley; U.S. Pat. No. 5,501,237
to Young; U.S. Pat. No. 5,533,530 to Young; which are incorporated
herein by reference. See, for example, the casting processes set
forth in U.S. Pat. No. 3,353,541 to Hind; U.S. Pat. No. 3,499,454
to Hind; U.S. Pat. No. 3,483,874 to Hind; U.S. Pat. No. 3,760,815
to Deszyck; U.S. Pat. No. 4,674,519 to Keritsis; U.S. Pat. No.
4,972,854 to Kiernan; U.S. Pat. No. 5,023,354 to Hickle; U.S. Pat.
No. 5,099,864 to Young; U.S. Pat. No. 5,101,839 to Jakob; U.S. Pat.
No. 5,327,917 to Lekwauwa; U.S. Pat. No. 5,339,838 to Young; U.S.
Pat. No. 5,598,868 to Jakob; U.S. Pat. No. 5,715,844 to Young; U.S.
Pat. No. 5,724,998 to Gellatly; and U.S. Pat. No. 6,216,706 to
Kumar; and EPO 565360; EPO 1055375 and PCT WO 98/01233; which are
incorporated herein by reference. Extracts, extracted materials,
and slurries used in traditional types of reconstituted tobacco
processes can be employed as ingredients in tobacco formulations of
the invention.
[0036] The process of the invention can be used in connection with
any tobacco treatment process where the application of heat is
involved, and in conjunction with heat treatment processing aids or
additives or in conjunction with ingredients such as casing
components. See, for example, the casing materials and methods set
forth in U.S. Pat. No. 4,177,822 to Bryant, Jr. et al.; U.S. Pat.
No. 4,306,577 to Wu et al.; U.S. Pat. No. 4,449,541 to Mays et al.;
U.S. Pat. No. 4,537,204 to Gaisch et al.; U.S. Pat. No. 4,819,668
to Shelar et al.; and U.S. Pat. No. 4,836,224 to Lawson et al.,
each of which is incorporated by reference herein.
[0037] The relative amount of tobacco within the tobacco
formulation may vary. Preferably, the amount of tobacco within the
tobacco formulation is at least about 10 percent or at least about
25 percent, on a dry weight basis of the formulation. In certain
instances, the amounts of other components within the tobacco
formulation may exceed about 40 percent, on a dry weight basis. A
typical range of tobacco material within the formulation is about
10 to about 60 weight percent, more often about 20 to about 40
weight percent on a dry basis.
[0038] The tobacco composition subjected to the heat treatment
process of the invention will typically have a certain level of
water therein, and can be characterized as a moist tobacco
composition. The amount of water can vary from a large excess,
where the tobacco composition is in the form of a dispersion, to
smaller amounts where the tobacco composition is merely dampened.
The water content prior to heat treatment is typically greater than
about 10 weight percent, based on the total weight of the
composition, more often at least about 20 weight percent. The water
content is typically less than about 85 weight percent, more often
less than about 75 weight percent. A typical weight range is about
20 to about 50 weight percent. Non-aqueous solvents can also be
present in the tobacco composition in addition to water, such as
various humectants (e.g., glycerin or propylene glycol).
[0039] An additive capable of altering the nature or character of a
heat-treated tobacco composition is mixed with the tobacco
composition. The additive is, for example, a compound or mixture of
compounds that can alter the chemistry or sensory characteristics
of the tobacco during the heat treatment process. In one
embodiment, the additive is intended to inhibit the reaction
between asparagine and reducing sugars present in the tobacco
composition, which can lead to compounds such as acrylamide.
Tobacco products differ uniquely from food products with regard to
certain reactions, such as the reaction between asparagine and
reducing sugars. With smoking tobacco products (e.g., cigarettes,
cigars, pipe tobacco), the temperature gradient during use is much
higher than the temperature encountered in foods during cooking,
which can lead to an increased rate of reaction. With certain
smokeless tobacco products, the pH can be much higher than the pH
of foods and, during processing, heating the tobacco with an
increased pH may enhance the rate of certain reactions. Therefore,
inhibition of certain reactions can be particularly challenging
when dealing with tobacco products.
[0040] Exemplary additives include amino acids, compositions
incorporating di- and trivalent cations, asparaginase, certain
non-reducing saccharides, certain reducing agents, phenolic
compounds (e.g., compounds having at least one phenolic
functionality), certain compounds having at least one free thiol
group or functionality, oxidizing agents, oxidation catalysts,
rosemary extract (or other plant extracts derived from herbal or
botanical sources), and combinations thereof. Without being bound
of a theory of operation, it is believed that these additives are
capable of inhibiting reaction of asparagine to form acrylamide,
either by providing competing reactions that preferentially react
with available reducing sugars, by chemical interaction with
asparagine that renders it unable to react with reducing sugars, by
chemical interaction with reaction intermediates, or by chemical
interaction with acrylamide. Use of certain additives according to
the invention is described in U.S. Pat. No. 7,037,540 to Elder et
al. and U.S. Pat. No. 7,267,834 to Elder et al.; and US Pat. Appl.
Pub. Nos. 2004/0058046 to Zyzak et al; 2005/0196504 to Finley;
2006/0194743 to Oku et al; 2007/0141225 to Elder et al.;
2007/0141227 to Boudreaux et al.; and 2007/0166439 to Soe et al.,
which are incorporated by reference in their entirety.
[0041] The amount of the additive present in the tobacco
composition will vary depending on the desired character of the
final heat-treated tobacco composition and the type of additive
selected. Typically, the amount of additive is at least about 0.01
dry weight percent, more often at least about 0.1 dry weight
percent, and most often at least about 1 dry weight percent. The
additive is present in an amount typically less than about 15 dry
weight percent, such as less than about 10 weight percent or less
than about 8 weight percent. In one embodiment, the amount of the
additive is about 1 dry weight percent to about 5 dry weight
percent. When the additive is asparaginase, the amount of additive
can be relatively low, such as less than about 800 ppm or less than
about 600 ppm or less than about 500 ppm. Asparaginase may be
effective at treatment levels as low as less than about 400 ppm or
less than about 300 ppm or even less than about 200 ppm. A
typically weight range for asparaginase in the tobacco material is
about 100 ppm to about 1,000 ppm. Depending on the type of additive
used and the manner in which the additive interacts with the
asparagine/reducing sugar reaction, there may be a significant
portion of the additive remaining in the composition after heat
treatment or very little residual additive could remain.
[0042] Although various essential or non-essential amino acids
could be used, the amino acid is typically lysine, glycine,
histidine, alanine, methionine, glutamic acid, aspartic acid,
proline, phenylalanine, valine, arginine, or combinations thereof.
Cysteine can also be used.
[0043] The di- and trivalent cations are typically used in the form
of neutral salts. Less soluble salts, such as those salts
comprising carbonate or hydroxide anions can be made more soluble
by addition of phosphoric or citric acid. Suggested cations include
calcium, magnesium, aluminum, iron, copper, and zinc. Suitable
salts of these cations include calcium chloride, calcium citrate,
calcium lactate, calcium malate, calcium gluconate, calcium
phosphate, calcium acetate, calcium sodium EDTA, calcium
glycerophosphate, calcium hydroxide, calcium lactobionate, calcium
oxide, calcium propionate, calcium carbonate, calcium stearoyl
lactate, magnesium chloride, magnesium citrate, magnesium lactate,
magnesium malate, magnesium gluconate, magnesium phosphate,
magnesium hydroxide, magnesium carbonate, magnesium sulfate,
aluminum chloride hexahydrate, aluminum chloride, aluminum
hydroxide, ammonium alum, potassium alum, sodium alum, aluminum
sulfate, ferric chloride, ferrous gluconate, ferric ammonium
citrate, ferric pyrophosphate, ferrous fumarate, ferrous lactate,
ferrous sulfate, cupric chloride, cupric gluconate, cupric sulfate,
zinc gluconate, zinc oxide, zinc sulfate, and combinations
thereof.
[0044] Another exemplary additive is asparaginase, which is an
enzyme that decomposes asparagine to aspartic acid and ammonia. The
asparaginase is typically used in the form of an aqueous dispersion
containing less than 10 weight percent total organic solids (TOS).
The number of asparaginase units (ASNU) per gram of the
asparaginase composition used in the invention can vary, but is
typically in the range of 3000 to 4000. Other enzyme treatments can
also be effective, such as a multi-stage enzyme treatment that
utilizes a first enzyme to convert certain reducing sugars to a
second reducing sugar, and a second enzyme to oxidize the second
reducing sugar. For example, fructose can be converted into glucose
by the action of the enzyme glucose isomerase, which is also known
as xylose isomerase, and glucose can be oxidized by hexose oxidase
or glucose oxidase.
[0045] Saccharides to replace reducing sugars and/or phenolic
substances are believed to suppress the formation of acrylamide
from asparagine. Exemplary saccharides include trehalose, reduced
palatinose, D-mannitol, D-erythritol, cyclodextrin, and
combinations thereof. Commercially available saccharides include
"TREHA.RTM.", a high purity hydrous crystalline trehalose available
from Hayashibara Shoji Inc., Okayama, Japan; "NEOTREHALOSE", a
reagent grade crystalline trehalose available from Hayashibara
Biochemical Laboratories Inc., Okayama, Japan; "PALATINIT", a
powderized reduced palatinose available from Shin Mitsui Sugar Co.
Ltd., Tokyo, Japan; and "MANNITOL", a crystalline mannitol powder
available from Towa Chemical Industry Co., Ltd., Tokyo, Japan.
[0046] Exemplary phenolic substances include catechins (e.g.,
catechin, epicatechin, and epigalocatechin), flavonoids (e.g.,
quercetin, isoquercitrin, rutin, naringin, hesperidin), kaempferol,
cinnamic acid, quinic acid, 3,4-dihydro-cinnamic acid, 3-coumaric
acid, 4-coumaric acid, p-nitorophenol, curcumin, scopoletin,
p-hydroxybenzoic acid n-propyl, protoanthocyanidin, and
combinations thereof.
[0047] Compounds with at least one free thiol (--SH) group can also
be used, such as cysteine and cysteine derivatives (e.g.,
N-acetyl-cysteine), polypeptides with available thiol groups (e.g.,
glutathione and casein), di-thiothreitol, mercaptoacetic acid,
mercaptopropionic acid, mercaptoethanol, and combinations
thereof.
[0048] Reducing agents capable of reduction of disulfide bonds to
thiol groups are believed to be capable of reducing acrylamide
levels as long as these reducing agents do not promote the Maillard
reaction with asparagine. Exemplary reducing agents include
stannous chloride dehydrate, sodium sulfite, sodium meta-bisulfate,
ascorbic acid, ascorbic acid derivatives, isoascorbic acid
(erythorbic acid), salts of ascorbic acid derivatives, iron, zinc,
ferrous ions, ethylenediaminetetraacetic acid (EDTA), citric acid,
malic acid, glutaric acid, dicarboxylic acids, and combinations
thereof.
[0049] Bleaching or oxidizing agents and oxidation catalysts are
also believed to be useful to inhibit acrylamide formation from
asparagine. Any oxidizing agent capable of transferring oxygen
atoms can be used. Exemplary oxidizing agents include peroxides
(e.g., hydrogen peroxide), chlorite salts, chlorate salts,
perchlorate salts, hypochlorite salts, ozone, ammonia, and
combinations thereof. Exemplary oxidation catalysts are titanium
dioxide, manganese dioxide, and combinations thereof. Processes for
treating tobacco with bleaching agents are discussed, for example,
in U.S. Pat. No. 787,611 to Daniels, Jr.; U.S. Pat. No. 1,086,306
to Oelenheinz; U.S. Pat. No. 1,437,095 to Delling; U.S. Pat. No.
1,757,477 to Rosenhoch; U.S. Pat. No. 2,122,421 to Hawkinson; U.S.
Pat. No. 2,148,147 to Baier; U.S. Pat. No. 2,170,107 to Baier; U.S.
Pat. No. 2,274,649 to Baier; U.S. Pat. No. 2,770,239 to Prats et
al.; U.S. Pat. No. 3,612,065 to Rosen; U.S. Pat. No. 3,851,653 to
Rosen; U.S. Pat. No. 3,889,689 to Rosen; U.S. Pat. No. 4,143,666 to
Rainer; U.S. Pat. No. 4,194,514 to Campbell; U.S. Pat. No.
4,366,824 to Rainer et al.; U.S. Pat. No. 4,388,933 to Rainer et
al.; and U.S. Pat. No. 4,641,667 to Schmekel et al.; and PCT WO
96/31255 to Giolvas, all of which are incorporated by reference
herein. When utilizing an oxidizing agent, it may be desirable, but
it is not necessary, to pretreat the tobacco material with the
oxidizing agent and heat the resulting mixture (e.g., heating the
treated tobacco material at a temperature of at least about
80.degree. C. for at least about 15 minutes) prior to mixing the
treated tobacco material with the remaining components of the
mixture.
[0050] Depending on the type of tobacco composition being
processed, the tobacco composition can include one or more
additional components in addition to the tobacco material, water,
and the additives described above. Exemplary types of further
ingredients, which are discussed in greater detail below, include
flavorants, fillers, binders, pH adjusters, buffering agents,
colorants, disintegration aids, antioxidants, humectants, and
preservatives.
[0051] The components of the tobacco composition are brought
together in admixture using any mixing technique or equipment known
in the art. The additives noted above, which may be in liquid or
dry solid form, can be admixed with the tobacco in a pretreatment
step prior to mixture with any remaining components of the
composition or simply mixed with the tobacco together with all
other liquid or dry ingredients. Any mixing method that brings the
tobacco composition ingredients into intimate contact can be used.
A mixing apparatus featuring an impeller or other structure capable
of agitation is typically used. Exemplary mixing equipment includes
casing drums, conditioning cylinders or drums, liquid spray
apparatus, ribbon blenders, mixers available as FKM130, FKM600,
FKM1200, FKM2000 and FKM3000 from Littleford Day, Inc., Plough
Share types of mixer cylinders, and the like.
[0052] The heat treatment of the tobacco composition can be
accomplished using any heating method or apparatus known in the
art. The heat treatment can be carried out in an enclosed vessel
(e.g., one providing for a controlled atmospheric environment,
controlled atmospheric components, and a controlled atmospheric
pressure), or in a vessel that is essentially open to ambient air.
The temperature can be controlled by using a jacketed vessel,
direct steam injection into the tobacco, bubbling hot air through
the tobacco, and the like. In certain embodiments, the heat
treatment step is performed in a vessel also capable of providing
mixing of the composition, such as by stirring or agitation.
Exemplary mixing vessels include mixers available from Scott
Equipment Company, Littleford Day, Inc., Lodige Process Technology,
and the Breddo Likwifier Division of American Ingredients Company.
Examples of vessels which provide a pressure controlled environment
include high pressure autoclaves available from Berghof/America
Inc. of Concord, Calif., and high pressure reactors available from
The Parr Instrument Co. (e.g., Parr Reactor Model Nos. 4522 and
4552 described in U.S. Pat. No. 4,882,128 to Hukvari et al.). The
pressure within the mixing vessel during the process can be
atmospheric pressure or elevated pressure (e.g., about 10 psig to
about 1,000 psig). In other embodiments, the heat treatment process
is conducted in a microwave oven, a convection oven, or by infrared
heating.
[0053] The temperature and time of the heat treatment process will
vary, and generally, the length of the heat treatment will decrease
as the temperature of the heat treatment increases. However, the
temperature of the heat treatment step can be characterized as
elevated, meaning the temperature is greater than room temperature
(i.e., greater than 25.degree. C.). The temperature will be
determined, in part, by the type of heat treatment process being
conducted and the purpose of the heat treatment. Different
temperature ranges could be applicable, depending on whether the
process is designed for drying, pasteurization, or chemical
reaction (e.g., to form flavorful and aromatic compounds). The
temperature is generally above about 60.degree. C., often above
about 80.degree. C., and more typically above about 100.degree. C.,
but is generally below about 200.degree. C., often below about
175.degree. C., and most often below about 150.degree. C. Typical
temperature ranges include about 60.degree. C. to about 175.degree.
C., more often about 80.degree. C. to about 150.degree. C., and
most often about 100.degree. C. to about 140.degree. C. In certain
embodiments, relatively low temperature heat treatment processes
(e.g., below about 100.degree. C. or below about 90.degree. C.) are
desired in order to reduce the propensity of asparagine to react to
form certain byproducts.
[0054] The amount of time that the tobacco composition is subjected
to the heat 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, typically at least about 20
minutes, more often at least about 30 minutes. Normally, the time
period is less than about 3 hours, typically less than about 2
hours, and often less than about 1.5 hours. In certain embodiments,
relatively quick heat treatment processes are desired in order to
reduce the propensity of asparagine to react to form certain
byproducts. In such embodiments, the heating time is no more than
about 15 minutes or no more than about 10 minutes.
[0055] In certain embodiments, particularly where the heat
treatment is applied to a smokeless tobacco composition, the length
of the heat treatment is determined by the desired final moisture
content of the tobacco composition. Typically, the desired final
moisture content of the smokeless tobacco composition is less than
about 35 weight percent, based on the total weight of the
composition, often less than about 25 weight percent, and most
often less than about 20 weight percent. For smokeless tobacco
compositions that are formed into desired product shapes (e.g.,
sheet materials or rod shapes), the final moisture content is
typically less than about 15 weight percent or less than about 10
weight percent, and often less than about 8 weight percent.
[0056] Atmospheric air, or ambient atmosphere, is the preferred
atmosphere for carrying out the heat treatment of the present
invention. However, heat treatment can also take place under a
controlled atmosphere, such as a generally inert atmosphere. Gases
such as nitrogen, argon and carbon dioxide can be used.
Alternatively, a hydrocarbon gas (e.g., methane, ethane or butane)
or a fluorocarbon gas also can provide at least a portion of a
controlled atmosphere in certain embodiments, depending on the
choice of treatment conditions and desired reaction products.
[0057] The pH of the tobacco composition during heat treatment can
also affect the nature and character of the heat-treated product.
Aqueous tobacco compositions are normally acidic, but the pH can be
adjusted upward by addition of a base, such as sodium hydroxide. It
has been determined that the pH of the tobacco composition during
heat treatment can affect the reaction between asparagine and
reducing sugars. In certain embodiments, the pH of the tobacco
composition is less than about 10.0, less than about 9.0, less than
about 8.0, less than about 7.5, less than about 7.0, or less than
about 6.5. It has been determined that lower pH levels during heat
treatment can reduce acrylamide levels in the heat-treated
material. In certain embodiments, either no base or reduced amounts
of base are added to the tobacco composition to achieve the pH
levels noted above. A representative technique for determining the
pH of a tobacco formulation involves dispersing 5 g of that
formulation in 100 ml of high performance liquid chromatography
water, and measuring the pH of the resulting suspension/solution
(e.g., with a pH meter).
[0058] Although lowering the heat treatment temperature or
treatment time can reduce certain reactions as noted above, there
are instances where reduced time or temperature may be undesirable.
For example, where the heat treatment process is intended to
produce flavorable and aromatic Maillard reaction products,
reducing temperature or time of the heat treatment process will
also result in reduced production of desired compounds.
Consequently, in certain embodiments, it may be advantageous to use
one of the additives set forth herein to inhibit reactions as
opposed to altering heat treatment conditions.
[0059] The heat treatment process of the invention can be combined
with additional processes designed to disrupt cellular membranes
and, consequently, allow better penetration of the additives noted
above into the tobacco material. For example, the tobacco material
of the tobacco composition can be subjected to ultrasonic energy,
application of a vacuum, or treated with cell weakening enzymes
prior to or during the heat treatment process of the invention.
[0060] In one aspect of the invention, the heat treatment process
is used to treat a smokeless tobacco composition. For example, the
heat treatment process can be used to dry a smokeless tobacco
composition that has been formed into a desired product shape. Such
smokeless tobacco compositions, in addition to tobacco, water, and
the additives noted above, also typically include additional
components such as flavorants, fillers, binders, pH adjusters,
buffering agents, colorants, disintegration aids, antioxidants,
humectants, and preservatives.
[0061] Exemplary flavorants that can be used are components, or
suitable combinations of those components, that act to alter the
bitterness, sweetness, sourness, or saltiness of the smokeless
tobacco product, enhance the perceived dryness or moistness of the
formulation, or the degree of tobacco taste exhibited by the
formulation. Types of flavorants include salts (e.g., sodium
chloride, potassium chloride, sodium citrate, potassium citrate,
sodium acetate, potassium acetate, and the like), natural
sweeteners (e.g., fructose, sucrose, glucose, maltose, mannose,
galactose, lactose, and the like), artificial sweeteners (e.g.,
sucralose, saccharin, aspartame, acesulfame K, neotame, and the
like); and mixtures thereof. The amount of flavorants utilized in
the tobacco composition can vary, but is typically up to about 10
dry weight percent, and certain embodiments are characterized by a
flavorant content of at least about 1 dry weight percent, such as
about 1 to about 10 dry weight percent. Combinations of flavorants
are often used, such as about 0.1 to about 2 dry weight percent of
an artificial sweetener and about 0.5 to about 8 dry weight percent
of a salt such as sodium chloride.
[0062] Exemplary filler materials include vegetable fiber materials
such as sugar beet fiber materials (e.g., FIBREX.RTM. brand filler
available from International Fiber Corporation), oats or other
cereal grain (including processed or puffed grains), bran fibers,
starch, or other modified or natural cellulosic materials such as
microcrystalline cellulose. Additional specific examples include
corn starch, maltodextrin, dextrose, calcium carbonate, calcium
phosphate, lactose, manitol, xylitol, and sorbitol. The amount of
filler utilized in the tobacco composition can vary, but is
typically up to about 50 dry weight percent, and certain
embodiments are characterized by a filler content of at least about
10 dry weight percent, such as about 20 to about 50 dry weight
percent. Combinations of fillers are often used, such as about 2 to
about 8 dry weight percent of calcium carbonate, about 10 to about
20 dry weight percent of rice flour, and about 10 to about 20
weight percent of maltodextrin.
[0063] Typical binders include povidone, sodium
carboxymethylcellulose and other modified cellulosic materials,
sodium alginate, xanthan gum, starch-based binders, gum arabic,
pectin, carrageenan, pullulan, zein, and the like. The amount of
binder utilized in the tobacco composition can vary, but is
typically up to about 30 dry weight percent, and certain
embodiments are characterized by a binder content of at least about
5 dry weight percent, such as about 5 to about 30 dry weight
percent.
[0064] Preferred pH adjusters or buffering agents provide and/or
buffer within a pH range of about 6 to about 10, and exemplary
agents include metal hydroxides, metal carbonates, metal
bicarbonates, and mixtures thereof. Specific exemplary materials
include sodium hydroxide, potassium hydroxide, potassium carbonate,
sodium carbonate, and sodium bicarbonate. The amount of pH adjuster
or buffering material utilized in the tobacco composition can vary,
but is typically up to about 5 dry weight percent, and certain
embodiments can be characterized by a pH adjuster/buffer content of
at least about 0.5 dry weight percent, such as about 1 to about 5
dry weight percent.
[0065] Exemplary colorants include various dyes and pigments, such
as caramel coloring and titanium dioxide. The amount of colorant
utilized in the tobacco composition can vary, but is typically up
to about 3 dry weight percent, and certain embodiments are
characterized by a colorant content of at least about 0.1 dry
weight percent, such as about 0.5 to about 3 dry weight
percent.
[0066] Exemplary humectants include glycerin and propylene glycol.
The amount of humectant utilized in the tobacco composition can
vary, but is typically up to about 2 dry weight percent, and
certain embodiments can be characterized by a humectant content of
at least about 0.1 dry weight percent, such as about 0.2 to about 2
dry weight percent.
[0067] Other ingredients such as preservatives (e.g., potassium
sorbate) or disintegration aids (e.g., microcrystalline cellulose,
croscarmellose sodium, crospovidone, sodium starch glycolate,
pregelatinized corn starch, and the like) can also be used.
Typically, such ingredients are used in amounts of up to about 10
dry weight percent and usually at least about 0.1 dry weight
percent, such as about 0.5 to about 10 dry weight percent.
[0068] Particularly with respect to smokeless tobacco compositions,
the tobacco compositions of the invention can be formed into
desired product shapes either before or after the heat treatment
step. Typically, the forming step occurs prior to heat treatment
because the higher water content present prior to heating increases
the malleability of the composition. The method and apparatus used
to form the tobacco composition will depend on the desired shape.
Exemplary shapes include pill, tablet, sphere, sheet, coin, cube,
bead, ovoid, obloid, bean, stick, and rod. For example, the tobacco
composition can have the form of compressed tobacco pellets,
multi-layered extruded pieces, extruded or formed rods or sticks,
compositions having one type of tobacco formulation surrounded by a
different type of tobacco formulation, rolls of tape-like films,
readily water-dissolvable or water-dispersible films or strips
(see, for example, US Pat. Appl. Pub. No. 2006/0198873 to Chan et
al.), or capsule-like materials possessing an outer shell (e.g., a
pliable or hard outer shell that can be clear, colorless,
translucent or highly colored in nature) and an inner region
possessing tobacco or tobacco flavor (e.g., a Newtoniam fluid or a
thixotropic fluid incorporating tobacco of some form).
[0069] Processed tobacco compositions, such as compressed tobacco
pellets, can be produced by compacting granulated tobacco and
associated formulation components in the form of a pellet, and
optionally coating each pellet with an overcoat material. Exemplary
granulation devices are available as the FL-M Series granulator
equipment (e.g., FL-M-3) from Vector Corporation and as WP 120V and
WP 200VN from Alexanderwerk, Inc. Exemplary compaction devices,
such as compaction presses, are available as Colton 2216 and Colton
2247 from Vector Corporation and as 1200i, 2200i, 3200, 2090, 3090
and 4090 from Fette Compacting. Devices for providing outer coating
layers to compacted pelletized tobacco formulations are available
as CompuLab 24, CompuLab 36, Accela-Cota 48 and Accela-Cota 60 from
Thomas Engineering.
[0070] Processed tobacco compositions, such as multi-layered
tobacco pellets, can be manufactured using a wide variety of
extrusion techniques. For example, multi-layered tobacco pellets
can be manufactured using co-extrusion techniques (e.g., using a
twin screw extruder). In such a situation, successive wet or dry
components or component mixtures can be placed within separate
extrusion hoppers. Steam, gases (e.g., ammonia, air, carbon
dioxide, and the like), and humectants (e.g., glycerin or propylene
glycol) can be injected into the extruder barrel as each dry mix is
propelled, plasticized, and cooked. As such, the various components
are processed so as to be very well mixed, and hence, come in
complete contact with each other. For example, the contact of
components is such that individual components can be well embedded
in the extrusion matrix or extrudate. See, for example, U.S. Pat.
No. 4,821,749 to Toft et al., which is incorporated herein by
reference. Multilayered materials can have the general form of
films, and alternatively, multi-layered generally spherical
materials can possess various layers extending from the inside
outward.
[0071] Some shapes, such as rods or cubes, can be formed by first
extruding the material through a die having the desired
cross-section (e.g., round or square) and then optionally cutting
the extruded material into desired lengths. Exemplary extrusion
equipment suitable for use in the invention include industrial
pasta extruders such as Model TP 200/300 available from Emiliomiti,
LLC of Italy. Sheet-like materials can be prepared by applying the
tobacco composition onto a moving belt and passing the moving belt
through a nip formed by opposing rollers, followed by cutting the
sheet into desired lengths.
[0072] The present invention provides a heat-treated tobacco
composition, such as a heat-treated smokeless tobacco composition,
having an acrylamide content of less than about 2000 ppb (or ng/g).
Typically, the acrylamide content is less than about 1500 ppb,
often less than about 1000 ppb, and most often less than about 900
ppb. Compositions having an acrylamide content of less than about
800 ppb, less than about 700 ppb, less than about 600 ppb, less
than about 500 ppb, less than about 400 ppb, or less than about 300
ppb can be produced.
[0073] The heat-treated tobacco compositions of the invention are
useful as additives for the manufacture of smoking articles. For
example, the composition prepared in accordance with the present
invention can be mixed with casing materials and applied to tobacco
as a casing ingredient, incorporated into smoking articles as a top
dressing ingredient, or incorporated into reconstituted tobacco
materials. Tobacco cut filler can be the tobacco material treated
according to the invention and then incorporated into a smoking
article as part of the smokable material charge. Still further, the
heat-treated compositions of the invention can be incorporated into
a cigarette filter (e.g., in the filter plug, plug wrap, or tipping
paper) or incorporated into cigarette wrapping paper, preferably on
the inside surface, during the cigarette manufacturing process. The
heat-treated compositions can also be used as an additive within
certain aerosol-generating electronic smoking articles, such as
those described in US Pat. Appl. Pub. No. 2008/0092912 to Robinson
et al., which is incorporated by reference herein in its
entirety.
[0074] The heat-treated composition could be incorporated into the
tobacco blends, representative cigarette components, and
representative cigarettes manufactured therefrom, set forth in U.S.
Pat. No. 4,836,224 to Lawson et al.; U.S. Pat. No. 4,924,888 to
Perfetti et al.; U.S. Pat. No. 5,056,537 to Brown et al.; U.S. Pat.
No. 5,220,930 to Gentry; and U.S. Pat. No. 5,360,023 to Blakley et
al.; US Pat. Application 2002/0000235 to Shafer et al.; and PCT WO
02/37990. Those tobacco materials also can be employed for the
manufacture of those types of cigarettes that are described in U.S.
Pat. No. 4,793,365 to Sensabaugh; U.S. Pat. No. 4,917,128 to
Clearman et al.; U.S. Pat. No. 4,947,974 to Brooks et al.; U.S.
Pat. No. 4,961,438 to Korte; U.S. Pat. No. 4,920,990 to Lawrence et
al.; U.S. Pat. No. 5,033,483 to Clearman et al.; U.S. Pat. No.
5,074,321 to Gentry et al.; U.S. Pat. No. 5,105,835 to Drewett et
al.; U.S. Pat. No. 5,178,167 to Riggs et al.; U.S. Pat. No.
5,183,062 to Clearman et al.; U.S. Pat. No. 5,211,684 to Shannon et
al.; U.S. Pat. No. 5,247,949 to Deevi et al.; U.S. Pat. No.
5,551,451 to Riggs et al.; U.S. Pat. No. 5,285,798 to Banerjee et
al.; U.S. Pat. No. 5,593,792 to Farrier et al.; U.S. Pat. No.
5,595,577 to Bensalem et al.; U.S. Pat. No. 5,816,263 to Counts et
al.; U.S. Pat. No. 5,819,751 to Barnes et al.; U.S. Pat. No.
6,095,153 to Beven et al.; U.S. Pat. No. 6,311,694 to Nichols et
al.; and U.S. Pat. No. 6,367,481 to Nichols, et al.; and PCT WO
97/48294 and PCT WO 98/16125. See, also, those types of
commercially marketed cigarettes described Chemical and Biological
Studies on New Cigarette Prototypes that Heat Instead of Burn
Tobacco, R. J. Reynolds Tobacco Company Monograph (1988) and
Inhalation Toxicology, 12:5, p. 1-58 (2000).
[0075] In certain embodiments where the heat-treated tobacco
composition is used as a smokable material, the resulting smoking
article can be characterized by a reduced acrylamide level in
mainstream smoke during use. For example, the smoking article can
be characterized by a reduction in acrylamide level in mainstream
smoke relative to an untreated control smoking article (i.e., a
comparable smoking article except containing no tobacco treated
according to the invention) of at least about 10 percent, at least
about 20 percent, at least about 30 percent, at least about 40
percent, at least about 50 percent, at least about 60 percent, at
least about 70 percent, at least about 80 percent, or more. In
other words, the smoking article of the invention, such as a
cigarette, containing the treated tobacco composition of the
invention can produce a reduced amount of acrylamide by weight in
mainstream smoke as compared to an untreated control smoking
article smoked using the same smoking machine and under the same
smoking conditions, such as the smoking machines and smoking
conditions set forth in ISO 3308:1991 and ISO 4387:1991, which are
incorporated by reference herein.
[0076] The composition resulting from the method of the invention
can also be used as a smokeless tobacco product or incorporated as
an additive in a smokeless tobacco product. Various types of
smokeless tobacco products are set forth in U.S. Pat. No. 1,376,586
to Schwartz; U.S. Pat. No. 3,696,917 to Levi; U.S. Pat. No.
4,513,756 to Pittman et al.; U.S. Pat. No. 4,528,993 to Sensabaugh,
Jr. et al.; U.S. Pat. No. 4,624,269 to Story et al.; U.S. Pat. No.
4,987,907 to Townsend; U.S. Pat. No. 5,092,352 to Sprinkle, III et
al.; and U.S. Pat. No. 5,387,416 to White et al.; US Pat. App. Pub.
Nos. 2005/0244521 to Strickland et al. and 2008/0196730 to Engstrom
et al.; PCT WO 04/095959 to Arnarp et al.; PCT WO 05/063060 to
Atchley et al.; PCT WO 05/016036 to Bjorkholm; and PCT WO 05/041699
to Quinter et al., each of which is incorporated herein by
reference. See also, the types of smokeless tobacco formulations,
ingredients, and processing methodologies set forth in U.S. Pat.
No. 6,953,040 to Atchley et al. and U.S. Pat. No. 7,032,601 to
Atchley et al.; US Pat. Appl. Pub. Nos. 2002/0162562 to Williams;
2002/0162563 to Williams; 2003/0070687 to Atchley et al.;
2004/0020503 to Williams, 2005/0178398 to Breslin et al.;
2006/0191548 to Strickland et al.; 2007/0062549 to Holton, Jr. et
al.; 2007/0186941 to Holton, Jr. et al.; 2007/0186942 to Strickland
et al.; 2008/0029110 to Dube et al.; 2008/0029116 to Robinson et
al.; 2008/0029117 to Mua et al.; 2008/0173317 to Robinson et al.;
and 2008/0209586 to Neilsen et al., each of which is incorporated
herein by reference.
EXPERIMENTAL
[0077] The present invention is more fully illustrated by the
following examples, which are set forth to illustrate the present
invention and are not to be construed as limiting thereof. In the
following examples, g means gram, .mu.g means microgram, mg means
milligram, ng means nanogram, L means liter, mL means milliliter,
.mu.L means microliter, and ppm means parts per million. All weight
percentages are expressed on a dry basis, meaning excluding water
content, unless otherwise indicated.
[0078] The method for analysis of the acrylamide used a Thermo
Surveyor MS Liquid Chromatograph (LC) equipped with a Phenomonex
Gemini-NX 5 .mu.m, 2.1.times.150 mm C.sub.18 HPLC column using
isocratic elution. Mobile phase A (92%) is 0.1% v/v formic acid in
water and mobile phase B (8%) is 100% methanol (MeOH). The column
temperature is 30.degree. C. and the autosampler tray is set to
4.degree. C. One microliter of the extract is injected onto the
column. The flow rate is 175 .mu.L/min with 10 minutes
equilibration time. The detection of acrylamide is achieved using a
Thermo TSQ Quantum Ultra triple-quadrupole mass spectrometer. The
LC effluent flows directly into the electrospray interface of the
mass spectrometer. The interface is operated in the positive ion
mode with a spray voltage of 3.5 kV. The ion transfer tube (heated
capillary) is set to 250.degree. C. Selected reaction monitoring is
used focusing on transitions of m/z 72.fwdarw.55 with collision
energy of 12 V and m/z 72.fwdarw.44 with collision energy of 32 V,
as determined by direct infusion of acrylamide. One gram of sample
is dissolved in 90:10 (v/v) water:methanol for 1 hour using an
orbital shaker set to 300 rpm. The extract is then filtered through
a 0.45 vim PTFE filter; the filtrate is subsequently analyzed by
the LC-MS/MS system described above.
[0079] The tobacco used in Examples 1-5 is a blend of 75% by weight
flue cured tobacco and 25% sun cured tobacco. The acrylamide
content of the tobacco blend, rice flour and maltodextrin is less
than the quantitation limit of 75 ng/g. The xanthan gum contains
about 120 ng/g acrylamide. For all examples, the dry ingredients
are added to a Popeil Automatic Pasta Maker (Model P400 Food
Preparer, Ronco Inventions LLC, Chatsworth, Calif.). The wet blend
is made by dissolving sodium hydroxide in water, then adding the
glycerin.
[0080] This wet blend solution is slowly added to the dry
ingredients while in "mix" mode following the instructions for use
on mixing. The Pasta Maker is then switched to "extrude" mode and
approximately 1 foot long rods are extruded through the Oriental
Noodle die (hole size about 3.15 mm). All holes but four on the
bottom of the die are blocked with a circular piece of plastic,
which is cut away to reveal the bottom holes. This piece of plastic
is placed inside the die on the side facing the machine.
[0081] The rods are placed on 221/2 inch diameter corrugated metal
screens made to fit rotating trays inside the oven. The
corrugations keep the rods straight while drying. The oven is a
Hotpack Digamatec convection oven (Hotpack Corporation,
Philadelphia, Pa.) with 10 rotating trays. The drying temperature
is 280.degree. F. (138.degree. C.).
[0082] Examples 6-9 describe testing to determine the effect of
using certain additive-treated tobacco materials on acrylamide
content of mainstream smoke generated by cigarettes containing the
treated tobacco. The manner of treating the tobacco with the
additive in these examples involves placing about 15 g of CAMEL
Blue tobacco blend or 25 g of a Turkish blend in a pre-weighed
plastic bag. The bag is clamped inside a pan coater to rotate the
sample inside the bag. A pre-weighed water solution containing the
additive is sprayed onto the rotating tobacco sample using an
atomizer in an attempt to get as uniform an application as
possible. The solution weight is targeted to give about 40%
additional moisture to the tobacco blends. The bag is then removed
from the pan coater, sealed and reweighed to determine the exact
amount of solution added. The bag is shaken several times to mix
and allow any solution on the sides of the bag to be absorbed into
the tobacco. The samples are allowed to incubate for 2 hours 25
minutes to 3 hours 25 minutes at room temperature. The tobacco is
then put on stainless steel plates and heated for 10 minutes in an
oven. The oven temperature is 73.degree. C. at the start and
85.degree. C. at the end of the heating time. After removing from
the oven, the tobacco is covered with paper towels and allowed to
dry overnight at ambient conditions (24.degree. C., 36% RH). After
drying overnight, the tobacco feels very dry and crunchy. The
tobacco samples are put in a conditioning cabinet at 24.degree. C.,
60% RH for 5 days and then stored in sealed plastic bags in the
conditioning cabinet until cigarettes are hand made using the
tobacco. Tobacco moisture is measured on 1 gram samples using a
Mettler moisture meter at 105.degree. C. with a cutoff of 1 mg
weight loss in 50 seconds. The Turkish blend initial moisture is
11.4% and the final conditioned moisture is 11.6%. The CAMEL Blue
initial moisture is 10.2% and the final conditioned moisture is
13.8%.
[0083] For the analysis of smoke acrylamide, handmade cigarettes
are made from the treated tobaccos in Examples 6-9. The smoke from
these cigarettes is collected using a Cerulean SM 450 smoking
machine (Cerulean, Linford Wood East, UK). The machine air flows
are tuned for ISO conditions (ISO 3308:1991 and ISO 4387:1991). The
smoking is performed under one regimen using 35 mL puff volume, 2 s
puff, and 60 s puff interval (indicated as ISO). The cigarettes do
not have the ventilation blocked. The collected smoke is analyzed
for acrylamide content as described above.
Example 1
Control Formulation and Effect of Drying Time
[0084] Rods made using the formula set forth in Table 1 below are
dried for 10, 15, 20, 30 and 40 minutes to demonstrate the effect
of drying time on acrylamide formation. The sample dried for 15
minutes was used as a control for comparison for all
experiments.
TABLE-US-00001 TABLE 1 % w/w g/batch Dry ingredients: Tobacco 40.0%
120.0 Sucralose (Tate and Lyle Sucralose Inc., Decatur, IL) 1.0%
3.0 Titanium dioxide (Mutchler Inc., Harrington Park, NJ) 1.0% 3.0
Calcium Carbonate HD PPT Fine (Univar USA Inc., 5.0% 15.0 Seattle,
WA) Maltodextrin 10DE (Grain Processing Corp. Muscatine, 16.0% 48.0
IA) Rice Flour (Remy n.v., Leuven-Wijgmaal, Belgium) 16.0% 48.0
Xanthan gum (Tic Gums Inc., Belcamp, MD) 15.0% 45.0 Sodium chloride
USP (J.T. Baker, Mallinckrodt Baker Inc., 4.0% 12.0 Phillipsburg,
NJ) Wet blend: Sodium hydroxide (Certified A.C.S., Fisher
Scientific, Fair 1.5% 4.5 Lawn, NJ) Glycerin (Vitusa Products Inc.,
Berkeley Height, NJ) 0.5% 1.5 110 mL of Water Total ingredients
except water: 100% 300.0
[0085] The control sample dried for fifteen minutes has an
acrylamide content of 2559 ng/g. Reducing the drying time to 10
minutes results in a 44% reduction in acrylamide content as
compared to the control, while increasing the drying time to 20
minutes increases acrylamide content by 39% as compared to the
control. Further increases in drying time result in smaller
increases (or even decreases) in acrylamide content as compared to
the control, with a 30 minute drying time leading to a 24% increase
and a 40 minute drying time leading to a reduction in acrylamide
content of 4%, as compared to the control. Thus, increasing the
drying time can lead to increases in acrylamide content until a
maximum content is achieved, after which further increases in
drying time do not raise acrylamide content and may lead to slight
reductions.
Example 2
Effect of pH
[0086] A tobacco composition is processed the same as the control
sample in Example 1, except that the sodium hydroxide is reduced to
2.25 g (one-half of the amount used in Example 1). Maltodextrin is
increased to 49.10 g and rice flour is increased to 49.15 g. The pH
before drying is 7.54 and the pH after drying is 7.27. The
acrylamide content is 1250 ng/g, which represents a 51% decrease in
acrylamide as compared to the control sample, which has a pH of
8.68 before drying and 8.08 after drying.
[0087] Another tobacco composition is processed the same as Example
1, except that no sodium hydroxide is added. Maltodextrin and rice
flour are increased to 50.25 g each. The pH before drying is 6.51
and the pH after drying is 6.56. The acrylamide content is 178
ng/g, a drop of 93% as compared to the control. This testing
indicates that acrylamide content increases with increases in pH
during drying.
Example 3
Effect of Amino Acids
[0088] L-lysine HCl is dissolved in 80 mL of water and the solution
is stirred into the tobacco. The solution is allowed to soak into
the tobacco for 20 minutes before using. The treated tobacco is
mixed with the other dry ingredients in the Pasta Maker. The final
composition has the formulation set forth in Table 2 below. The
formulation is otherwise processed in the same manner as the
control sample in Example 1.
TABLE-US-00002 TABLE 2 % w/w g/batch Dry ingredients: Tobacco 40.0%
120.0 L-Lysine HCl monohydrate, USP (J.T. 1.0% 3.00 Baker,
Mallinckrodt Baker Inc., Phillipsburg, NJ) 80 mL of water Sucralose
1.0% 3.00 Titanium dioxide 1.0% 3.00 Calcium Carbonate (HD PPT
Fine) 5.0% 15.00 Maltodextrin (10DE) 15.3% 46.00 Rice Flour 15.2%
45.50 Xanthan gum 15.3% 45.75 Sodium chloride 4.0% 12.00 Wet blend:
Sodium hydroxide 1.8% 5.25 Glycerin 0.5% 1.50 30 mL of water Total
ingredients except water: 100% 300.00
[0089] Another formulation is prepared in the same matter as the
formulation of Table 2, except that the L-lysine HCl is increased
to 7.5 g (2.5% by dry weight). Maltodextrin, rice flour, and
xanthan gum are reduced to 44.25 g each.
[0090] Another formulation is prepared in the same matter as the
formulation of Table 2, except that 7.5 g of L-cysteine (97%,
Sigma-Aldrich, St. Louis, Mo.) (2.5% by dry weight) is substituted
for L-lysine HCl. Maltodextrin is reduced to 45.5 g, xanthan gum is
reduced to 42.5 g, and sodium hydroxide is reduced to 4.50 g.
[0091] The addition of L-lysine prior to drying reduces the
acrylamide content by 63% (1.0% by dry weight L-lysine HCl) and 73%
(2.5% by dry weight L-lysine HCl), respectively, as compared to the
control. The addition of L-cysteine prior to drying reduces the
acrylamide content by 74% as compared to the control.
Example 4
Effect of Asparaginase
[0092] Acrylaway L (Novozymes North America Inc., Franklinton,
N.C.), a commercial enzyme preparation containing 3500 asparaginase
units (ASNU) per gram, is used. The enzyme preparation contains
approximately 4% total organic solids (TOS), 46% water, 50%
glycerol, 0.3% sodium benzoate, and 0.1% potassium sorbate
(Novozymes A/S; An Asparaginase Enzyme Preparation Produced a
Strain of Aspergillus oryzae Expressing the Aspergillus oryzae
Asparaginase Gene; Nov. 9, 2006; a dossier submitted to JECFA).
[0093] The Acrylaway L is diluted with 80 mL water and the solution
is added to the tobacco while stirring. After 60 minutes, the
treated tobacco is added to the other dry ingredients in the Pasta
Maker. Glycerin in the wet blend is reduced because the Acrylaway L
also contains glycerin. A formulation with 250 ppm TOS asparaginase
is set forth in Table 3 below. The formulation is otherwise
processed in the same manner as the control sample in Example
1.
TABLE-US-00003 TABLE 3 % w/w g/batch Dry ingredients: Tobacco 40.0%
120.0 Acrylaway (includes 0.37 g glycerin and 0.1% 0.75 0.345 g
water) 80 mL of water Sucralose 1.0% 3.00 Titanium dioxide 1.0%
3.00 Calcium Carbonate (HD PPT Fine) 5.0% 15.00 Maltodextrin (10DE)
16.0% 48.00 Rice Flour 16.0% 48.00 Xanthan gum 15.0% 45.00 Sodium
chloride 4.0% 12.00 Wet blend: Sodium hydroxide 1.5% 4.50 Glycerin
0.4% 1.14 30 mL of water Total ingredients except water: 100%
300.05
[0094] A second formulation including 500 ppm TOS asparaginase is
also prepared with the formulation being the same as that shown in
Table 3, except Acrylaway L is increased to 1.50 g and glycerin in
the wet blend is decreased to 0.78 g.
[0095] Drying of the formulation containing 250 ppm TOS
asparaginase results in a reduction in acrylamide content of 67% as
compared to the control. The 500 ppm TOS asparaginase formulation
has an acrylamide content that is 69% lower than the control upon
drying.
[0096] The presence of the asparaginase converts asparagine to
aspartic acid. The asparagine and aspartic acid content of the
control sample after drying is 0.073% and 0.041%, respectively. The
level of asparagine in the final product for the two
asparaginase-containing samples are below the quantitation limit of
the analysis (0.043%). The aspartic acid content for the two
asparaginase-containing samples increases to 0.13%.
Example 5
Effect of Oxidizing Agent
[0097] The tobacco is mixed with 80 mL of 3% hydrogen peroxide.
After mixing, the tobacco is placed into an oven at 200.degree. F.
(93.degree. C.) for 30 minutes. The tobacco is then added to the
other dry ingredients in the Pasta Maker. The formulation of this
sample is set forth in Table 4 below.
TABLE-US-00004 TABLE 4 % w/w g/batch Dry ingredients: Tobacco 40.0%
120.0 80 mL of 3% hydrogen peroxide (CVS Pharmacy, Woonsocket, RI)
Sucralose 1.0% 3.00 Titanium dioxide 1.0% 3.00 Calcium Carbonate
(HD PPT Fine) 5.0% 15.00 Maltodextrin (10DE) 16.0% 48.00 Rice Flour
16.0% 48.00 Xanthan gum 15.0% 45.00 Sodium chloride 4.0% 12.00 Wet
blend: Sodium hydroxide 1.5% 4.50 Glycerin 0.5% 1.50 50 mL of Water
Total ingredients except water: 100% 300.00
[0098] This formulation is otherwise processed the same as the
control sample in Example 1, except the drying time is 10 minutes.
The final acrylamide content is 68% less than the control
sample.
Example 6
[0099] A 2007 crop year Turkish Samsun (Turkish SA), which has a
relatively high level of asparagine, is treated with Acrylaway L
asparaginase as the treatment additive (about 507 ppm TOS added),
and cigarettes are hand made using the treated tobacco and smoked
under ISO conditions in the manner described above. The smoke is
collected and tested for acrylamide content as described herein.
The cigarette containing asparaginase-treated tobacco produces less
acrylamide in mainstream smoke as compared to a control cigarette
containing water-treated tobacco. The reduction is about 72.9% as
compared to the control cigarette.
Example 7
[0100] A CAMEL Blue tobacco blend is removed from a CAMEL Blue
cigarette and treated with Acrylaway L asparaginase as the
treatment additive (about 558 ppm TOS added), and cigarettes are
hand made using the treated tobacco and smoked under ISO conditions
in the manner described above. The smoke is collected and tested
for acrylamide content as described herein. The cigarette
containing asparaginase-treated tobacco produces less acrylamide in
mainstream smoke as compared to a control cigarette containing
water-treated tobacco. The reduction is about 62.5% as compared to
the control cigarette.
Example 8
[0101] A CAMEL Blue tobacco blend is removed from a CAMEL Blue
cigarette and treated with L-lysine HCl (Ajinomoto Aminoscience
LLC, Raleigh, N.C.), as the treatment additive (about 0.377 g of
L-lysine added), and cigarettes are hand made using the treated
tobacco and smoked under ISO conditions in the manner described
above. The smoke is collected and tested for acrylamide content as
described herein. The cigarette containing lysine-treated tobacco
produces less acrylamide in mainstream smoke as compared to a
control cigarette containing water-treated tobacco. The reduction
is about 9.5% as compared to the control cigarette.
Example 9
[0102] A CAMEL Blue tobacco blend is removed from a CAMEL Blue
cigarette and treated with 3% hydrogen peroxide (H.sub.2O.sub.2)
solution as the treatment additive (about 9.7 g of hydrogen
peroxide added), and cigarettes are hand made using the treated
tobacco and smoked under ISO conditions in the manner described
above. The smoke is collected and tested for acrylamide content as
described herein. The treatment does not result in a reduction in
acrylamide in mainstream smoke as compared to a control cigarette
containing water-treated tobacco.
[0103] Many modifications and other embodiments of the invention
will come to mind to one skilled in the art to which this invention
pertains having the benefit of the teachings presented in the
foregoing description. Therefore, it is to be understood that the
invention is not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended
to be included within the scope of the appended claims. Although
specific terms are employed herein, they are used in a generic and
descriptive sense only and not for purposes of limitation.
* * * * *