U.S. patent application number 12/264032 was filed with the patent office on 2009-03-05 for smoking article and smoking article filter.
Invention is credited to Kenneth D. Barrett, William R. Deaton, Terry D. Jessup, A. Brent Rudd, Michael A. ZAWADZKI.
Application Number | 20090056729 12/264032 |
Document ID | / |
Family ID | 33450178 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090056729 |
Kind Code |
A1 |
ZAWADZKI; Michael A. ; et
al. |
March 5, 2009 |
SMOKING ARTICLE AND SMOKING ARTICLE FILTER
Abstract
Improved filters useful for tobacco products, such as
cigarettes, and novel cigarettes having such filters are disclosed.
The filters include adsorbents such as activated carbon which
reduce amounts of one or more gas phase constituents of mainstream
tobacco smoke. The adsorbents are treated with off-taste
suppressants which reduce the off-taste associated with adsorbent
containing filters and substantially restore the taste normally
associated with tobacco smoke.
Inventors: |
ZAWADZKI; Michael A.;
(Greensboro, NC) ; Rudd; A. Brent; (Kernersville,
NC) ; Barrett; Kenneth D.; (Stokesdale, NC) ;
Jessup; Terry D.; (Jamestown, NC) ; Deaton; William
R.; (Pleasant Garden, NC) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
3 WORLD FINANCIAL CENTER
NEW YORK
NY
10281-2101
US
|
Family ID: |
33450178 |
Appl. No.: |
12/264032 |
Filed: |
November 3, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10442357 |
May 20, 2003 |
|
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12264032 |
|
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Current U.S.
Class: |
131/332 ;
131/331; 131/334; 131/339 |
Current CPC
Class: |
A24D 3/14 20130101; A24D
3/163 20130101; A24D 3/12 20130101 |
Class at
Publication: |
131/332 ;
131/339; 131/331; 131/334 |
International
Class: |
A24D 3/04 20060101
A24D003/04; A24D 3/06 20060101 A24D003/06; A24D 3/12 20060101
A24D003/12 |
Claims
1. A filter for a tobacco cigarette comprising: (a) an adsorbent
material in particulate form disposed in the filter, wherein the
adsorbent material adsorbs at least one gas phase constituent of
mainstream smoke produced when the tobacco cigarette is ignited;
and (b) an off-taste suppressant deposited on the surface of the
adsorbent material which reduces mainstream smoke off-taste
resulting from the presence of said adsorbent without introducing
additional flavor into said mainstream smoke.
2. A cigarette filter according to claim 1 wherein said adsorbent
material comprises activated carbon granules.
3. A cigarette filter according to claim 2 wherein said off-taste
suppressant includes at least one component selected from the group
consisting of sugars, oligosaccharides, polysaccharides, polyols,
amino acids, oligopeptides, polypeptides, alkali metal salts,
alkaline earth metal salts and combinations thereof.
4. A cigarette filter according to claim 3 wherein said off-taste
suppressant comprises fructose.
5. A cigarette filter according to claim 3 wherein said off-taste
suppressant comprises mannitol.
6. A cigarette filter according to claim 3 wherein said off-taste
suppressant comprises fructose and mannitol.
7. A cigarette filter according to claim 3 wherein said off-taste
suppressant comprises fructose and mannitol in about a 1:1 ratio by
weight.
8. A cigarette filter according to claim 4, 5, 6, or 7 wherein said
off-taste suppressant composition further comprises an alkali
halide salt.
9. A cigarette filter according to claim 8 wherein said alkali
halide salt is sodium chloride.
10. A cigarette filter according to claim 8 wherein said alkali
halide salt comprises no more than about 5% by weight of said
activated carbon granules and said off-taste suppressant
composition.
11. A cigarette filter according to claim 3, 4, 5, 6, or 7 wherein
said off-taste suppressant comprises from about 2 to about 40
percent of the total weight of said activated carbon granules and
said off-taste suppressant.
12. A cigarette filter according to claim 3, 4, 5, 6, or 7 wherein
said off-taste suppressant comprises from about 5 to about 25
percent of the total weight of said activated carbon granules and
said off-taste suppressant.
13. A cigarette filter according to claim 1, 2, 3, 4, 5, 6, or 7
further comprising a chemisorbent ion-exchange resin.
14. A cigarette filter according to claim 8 further comprising a
chemisorbent ion-exchange resin.
15. A cigarette filter according to claim 14 wherein said
ion-exchange resin is an amine-substituted polystyrene
derivative.
16. A cigarette filter according to claim 15 wherein said resin and
said activated carbon granules are present in an admixture.
17. A cigarette filter according to claim 16 wherein said activated
carbon granules and said ion-exchange resin are present in a ratio
of about 1:3 to about 3:1 by weight.
18. A tobacco cigarette having a filter comprising an upstream
fibrous filter component and a downstream fibrous filter component,
said upstream and downstream filter components defining a cavity
therebetween, said filter further comprising granular activated
carbon in said cavity and a composition on said activated carbon
including at least one component selected from the group consisting
of sugars, oligosaccharides, polysaccharides, polyols,
oligopeptides and polypeptides, amino acids and further including
at least one salt selected from the group consisting of, alkali
metal salts, alkaline earth metal salts and combinations
thereof.
19. A cigarette according to claim 18 wherein said composition
comprises fructose, mannitol and an alkali halide salt.
20. A cigarette according to claim 19 wherein said alkali halide
salt comprises sodium chloride.
21. A cigarette according to claim 18 wherein said composition
comprises fructose and mannitol in a ratio of about 1:1 by
weight.
22. A cigarette filter according to claim 18 wherein said
composition comprises fructose, mannitol and sodium chloride in a
ration of about 46:46:8 by weight.
23. A cigarette according to claims 18 wherein said salt comprises
from about 0.1% to about 5% of the total weight of said activated
carbon and said composition.
24. A cigarette according to claim 18 wherein said composition
comprises from about 2 to about 40 percent of the total weight of
said activated carbon and said composition.
25. A cigarette according to claim 18 wherein said composition
comprises from about 5 to about 25 percent of the total weight of
said activated carbon and said composition.
26. A cigarette according to claim 18, 19, 20, 21, 22, 23, 24 or 25
further comprising an ion exchange resin in admixture with said
activated carbon.
27. A filter for a tobacco cigarette comprising: a. an adsorbent
material in particulate form disposed in the filter, wherein the
adsorbent material adsorbs at least one gas phase constituent of
mainstream smoke produced when the tobacco cigarette is ignited; b.
an off-taste suppressant deposited on the surface of the adsorbent
material which reduces the off-taste resulting from the presence of
said adsorbent without introducing flavor into the mainstream
smoke, said off-taste suppressant including at least one component
selected from the group consisting of sugars, oligosaccharides,
polysaccharides, polyols, amino acids, oligopeptides, polypeptides,
alkali metal salts, alkaline earth metal salts, and combinations
thereof, and c. a chemisorbent for at least one gas phase
constituent of mainstream smoke.
28. The cigarette filter of claim 27 wherein said adsorbent
material is activated carbon granules.
29. The cigarette filter of claim 28 wherein said off-taste
suppressant comprises from about 2 to about 40 percent of the total
weight of said activated carbon granules and off-taste
suppressant.
30. The cigarette filter of claim 29 wherein said off-taste
suppressant comprises from about 5 to about 25 percent of the total
weight of said activated carbon granules and off-taste
suppressant.
31. The cigarette filter of claim 28 wherein said off-taste
suppressant comprises fructose and mannitol.
32. The cigarette filter of claim 31 wherein said off-taste
suppressant further comprises sodium chloride.
33. The cigarette filter of claim 31 wherein the ratio of fructose
to mannitol is from about 1:3 to 3:1 by weight.
34. The cigarette filter of claim 28 wherein said off-taste
suppressant comprises an alkali halide salt.
35. The cigarette filter of claim 34 wherein said alkali halide
salt comprises from about 0.1 to about 5 percent of the total
weight of said activated carbon granules and said off-taste
suppressant.
36. The cigarette filter of claim 28 wherein said chemisorbent is
an ion-exchange resin.
37. The cigarette filter of claim 36 wherein said ion-exchange
resin is a amine-substituted polystyrene derivative.
38. The cigarette filter of claim 36 wherein said ion-exchange
resin comprises from about 25 to about 75 percent of the total
weight of said ion-exchange resin and said activated carbon
granules.
39. The cigarette filter of claim 36 wherein said ion-exchange
resin comprises about 50% of the total weight of said resin and
said activated carbon granules.
40. The cigarette filter of claims 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38 or 39, wherein said chemisorbent is present in admixture
with said activated carbon granules.
41. A cigarette: having a multi-component filter comprising an
upstream fibrous filter component and a downstream fibrous filter
component, said upstream and downstream filter components defining
a filter cavity therebetween; and a filter material in said cavity
comprising activated carbon and an ion exchange resin in a ratio of
about 1:3 to about 3:1 by weight; said activated carbon having
thereon an off-taste suppressant comprising fructose and mannitol
in a ratio from about 1:3 to about 3:1 by weight and in addition
sodium chloride, wherein said off-taste suppressant comprises from
about 2 to about 40 percent of the total weight of said activated
carbon and off-taste suppressant
42. A tobacco cigarette having a filter comprising an activated
carbon adsorbent for at least one gas phase constituent of
mainstream smoke and an off-taste suppressant on said activated
carbon which reduces off-taste resulting from the presence of said
adsorbent, said off-taste suppressant comprising at least one
component selected from the group of compounds having B, X-B, AH-B
or AH-X-B moieties.
43. A cigarette according to claim 42 wherein said off-taste
suppressant comprises at least one component selected from
compounds having AH-B or AH-X-B moieties.
44. A cigarette according to claim 43 wherein said compounds having
AH-B or AH-X-B moieties are selected from the group consisting of
sugars, oligosaccharides, polysaccharides, polyols, amino acids,
oligopeptides, polypeptides and combinations thereof.
45. A cigarette according to claim 44 wherein said off-taste
suppressant comprises fructose.
46. A cigarette according to claim 45 wherein said off-taste
suppressant comprises mannitol.
47. A cigarette according to claim 44 wherein said off-taste
suppressant comprises fructose and mannitol.
48. A cigarette according to claim 42 wherein said off-taste
suppressant further comprises at least one component selected from
alkali metal salts, alkaline earth metal salts and combinations
thereof.
49. A cigarette according to claims 42, 43, 44, 45, 46, 47 or 48,
wherein said filter further comprises a chemisorbent selected from
the group consisting of ion-exchange resins in admixture with said
activated carbon adsorbent.
50. A cigarette according to claim 49 wherein said activated carbon
and said ion-exchange resin are present in a ratio of from about
1:3 to about 3:1 by weight carbon to resin.
Description
[0001] This is a divisional application of U.S. Ser. No. 10/442,357
filed May 20, 2003 to which priority under 35 U.S.C. .sctn. 120 is
claimed.
FIELD OF THE INVENTION
[0002] The present invention relates generally to improved filters
useful for tobacco products, particularly cigarettes, and to novel
cigarettes having such filters. More specifically, the invention
relates to filters containing adsorbents which reduce one or more
allegedly undesirable gas phase constituents normally found in
mainstream tobacco cigarette smoke.
BACKGROUND OF THE INVENTION
[0003] Typically, cigarettes are comprised of a paper-wrapped
cylindrical rod of cut tobacco filler, alone or combined with other
tobacco or non-tobacco substances, and a filter attached at the
mouth or buccal end of the rod. On combustion, the smoke passing
through the filter, commonly referred to as "mainstream" smoke,
contains particulate matter, e.g. tar, and gas or volatile phase
constituents. The gas phase of mainstream cigarette smoke contains
certain components alleged to be harmful to a smoker, including
carbon monoxide, hydrogen cyanide, aldehydes such as formaldehyde,
acetaldehyde, acrolein, propionaldehyde and crotonaldehyde, as well
as olefinic constituents such as 1,3 butadiene.
[0004] Most commercially available cigarettes have filters which
are designed to reduce particulate matter but are ineffective to
remove or reduce gas phase constituents of mainstream smoke. Such
filters typically include one or more plugs of fiber "tow,"
commonly cellulose acetate.
[0005] Filters have been designed for the removal of gas-phase
constituents along with particulates. These filters usually
incorporate an adsorbent material such as activated carbon (also
known as "carbon," "charcoal," or "activated charcoal") in a
section of the filter. Granular carbon having high surface area is
recognized as an effective adsorbent for removing components such
as aldehydes from mainstream smoke.
[0006] A variety of approaches to incorporating activated carbon
into cigarette filters have been employed. These approaches include
carbon granules dispersed within a cellulose acetate tow, paper web
or filter plug wrap, sometimes called "dalmation" filters. Another
approach is to place a bed or charge of granular carbon into the
cavity between two plugs of cellulose acetate tow in a so-called
"plug-space-plug" or "triple filter" design. Examples of
commercially available filters are Caviflex, Dualcoal, Recessed
Dualcoal, Sel-X-4, and Triple Filter from Baumartner Fibertec
(Switzerland); Active Acetate Dual, Active Charcoal Triple Solid,
Active Myria White, Active Patch Mono, Adsorbent Coated Thread,
Triple Granular, and V.P.A. Dual from Filtrona International
Incorporated (Milton Keynes, U.K.).
[0007] The commercial acceptance of carbon filters, however, has
been limited by the "off-taste" of the mainstream smoke
characteristic of such filters. The smoke from carbon-filtered
cigarettes is perceived as having a taste that has been described
as unpleasant, astringent, bitter and drying. See "What's happening
to Charcoal Filters?" Tobacco Reporter, Vol. 95, No. 3 (March
1968).
[0008] The art has attempted to address this problem by introducing
various flavoring substances ("flavorants") into the mainstream
smoke to offset or cover up the carbon off-taste. However, the
presence of flavorants tends to reduce the capacity of the
adsorbent to remove the undesirable gas phase constituents.
Flavorants applied as a coating to an adsorbent reduce its gas
removal efficiency by decreasing the number of active sites for
adsorption. It is known that flavorants in the tobacco or elsewhere
in the cigarette package tend to vaporize and migrate to the
activated carbon over time where they are adsorbed and thus
deactivate the sites onto which they are adsorbed. For that reason,
mentholated cigarettes having carbon filters require higher amounts
of menthol to be added during manufacture to offset adsorption by
the carbon.
[0009] Thus, there is a continuing need for a cigarette filter that
significantly reduces the quantity of gas phase constituents in
mainstream smoke without introducing unacceptable off-taste
normally associated with the activity of gas phase adsorbents such
as carbon. Further, there is a need for a carbon filter cigarette
that tastes substantially like a non-carbon filter cigarette.
[0010] It is therefore an object of the present invention to
provide filters for smoking articles, particularly tobacco
cigarettes, that reduce quantities of one or more allegedly
undesirable gas phase constituents normally found in mainstream
smoke.
[0011] It is another object of the present invention to provide
cigarettes having filters which utilize adsorbents, particularly
activated carbon, to reduce gas phase constituents without
introducing unacceptable off-taste such as normally results from
use of such adsorbents.
[0012] It is a further object of the present invention to provide a
carbon filter cigarette which tastes substantially like a
non-carbon filter cigarette.
SUMMARY OF THE INVENTION
[0013] The foregoing and other objectives are achieved according to
the invention by providing a filter containing a suitable amount of
an adsorbent, preferably activated carbon, and an off-taste
suppressant in association with the adsorbent. The adsorbent is
capable of trapping and thereby reducing the amount of at least one
allegedly undesirable gas phase constituent of mainstream smoke.
The off-taste suppressant significantly reduces the characteristic
off-taste stemming from the activity of the adsorbent. The
composition and amount of off-taste suppressant applied to the
adsorbent should be selected to maximize gas phase removal while at
the same time minimizing, preferably substantially eliminating,
off-taste stemming from adsorbent activity.
[0014] In a preferred embodiment of the invention, the smoking
article is a tobacco cigarette having a filter that contains an
activated carbon adsorbent for at least one gas-phase constituent
of mainstream smoke, which has applied thereto a suitable amount of
an off-taste suppressant selected from the group of molecules
having B, X-B, AH-B, or AH-X-B moieties as defined by the "AH-B
Theory" of sweetness discussed below in the Detailed Description of
the Invention. These molecules include, but are not limited to,
polyols, glycols, sugars, sugar-alcohols, oligosaccharides,
polysaccharides, amino acids, amino acid derivatives, di- and
tri-peptides, polypeptides, artificial sweeteners, and mixtures
thereof. The off-taste suppressant preferably also includes an
alkali metal or alkaline earth metal salt. The compositions and
weight ranges for the off-taste suppressants applied to the
adsorbent can be selected to maximize gas removal and reduction of
off-taste, preferably without introducing additional foreign
flavoring to the mainstream smoke so that the cigarette tastes
substantially like filtered cigarette.
[0015] One example of a useful off-taste suppressant is a
combination of fructose and mannitol, preferably in about a 50:50
ratio by weight. A more preferred off-taste suppressant is a
combination of fructose, mannitol and sodium chloride in a ratio of
about 46:46:8 by weight. It has been found that such a composition
when applied to a bed of activated carbon in a range of about 2 to
40 percent by weight to the total weight of the carbon and
off-taste suppressant, preferably in a range of about 5 to about
20-25 percent by weight, is particularly useful in achieving the
objectives of the invention.
[0016] According to another aspect of the invention the filter may
also include a chemisorbent for one or more of the allegedly
undesirable gas phase constituents, preferably in admixture with
the adsorbent. Preferred chemisorbents are amine derivatives of
polystyrene. Admixtures of activated carbon and ion exchange resins
such as polystyrene derivatives in a weight ratio of from about
25:75 to about 50:50 treated carbon to resin are particularly
useful in the practice of the invention, although other ratios may
be used.
[0017] The filters of the present invention are capable of reducing
one or more of the allegedly undesirable volatile components of
mainstream cigarette smoke including, but not limited to, aldehydes
such as formaldehyde, acetaldehyde, acrolein, propionaldehyde and
crotonaldehyde.
[0018] These and other aspects of the present invention will become
apparent to those skilled in the art after a reading of the
following detailed description of the invention, including the
illustrative embodiments and examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The drawings are for the purpose of illustrating the
invention and are not intended to be limiting.
[0020] FIG. 1 is a perspective view of one tobacco cigarette
embodiment of the invention having a triple, plug-space-plug
design;
[0021] FIG. 2 is a perspective view of another tobacco cigarette
embodiment of the invention having a four-component filter
design;
[0022] FIG. 3 is a perspective view of still another tobacco
cigarette embodiment of the invention having a two-component
filter;
[0023] FIG. 4 is a graph of off-taste reductions and overall
acceptability provided by the samples of Example 11 using the data
from Table 19;
[0024] FIG. 5 is a graph of off-taste reductions and overall
acceptability provided by the samples of Example 12 using the data
from Table 21;
[0025] FIG. 6 is a graph of off-taste reductions and overall
acceptability provided by the samples of Example 13 using the data
from Table 23;
[0026] FIG. 7 is a graph of off-taste reductions and overall
acceptability of the samples of Example 15 using the data from
Table 27.
DETAILED DESCRIPTION OF THE INVENTION
[0027] As used herein, the terms "adsorbent" and "chemisorbent" are
intended to have their ordinary and accustomed meanings in the art,
but should not be construed as limiting the invention to any
particular mode of action by which gas-phase constituents in
mainstream smoke are reduced. For instance, in accordance with the
ordinary and accustomed nomenclature in the art, activated carbon
is referred to herein as an "adsorbent," but activated carbons
which reduce gas phase constituents by adsorption, absorption,
chemisorption, or otherwise are contemplated as being within the
scope of the invention. Similarly, in accordance with the ordinary
and accustomed nomenclature in the art, ion-exchange resins are
referred to herein as "chemisorbents," but resins which reduce gas
phase constituents by adsorption, absorption, chemisorption, or
otherwise are contemplated as being within the scope of the
invention.
[0028] As used herein, the term "off-taste" refers to a taste not
characteristic of the smoking article. More particularly, in the
context of the present invention, "off-taste" refers to a taste
typically associated with smoke that, after passing through an
adsorbent such as activated carbon, has been described as
unpleasant, astringent, bitter and drying. The term "off-taste
suppressant" as used herein refers to a substance that reduces the
perception of off-taste by a smoker.
[0029] Without wishing to be bound by any theory, it is believed
that carbon off-taste arises as a result of the altered
organoleptic profile of mainstream smoke produced by the adsorption
of gas-phase constituents by activated carbon. The altered profile
of the mainstream smoke is believed to produce bitter flavor
"notes" that are not normally associated with tobacco smoke.
[0030] When reference is made to reduction or suppression of
off-taste perceived by a smoker, it will be understood by those
skilled in the art that the "smoker" may range from a professional
smoker employed in tobacco smoking panels having acute taste
perceptibility to the lay smoker whose taste sensations may be less
acute. Both types of smokers can detect the difference in taste of
cigarettes of this invention which have been treated with off-taste
suppressants from those which have not.
[0031] Activated carbon is the preferred adsorbent. It is
contemplated, however, that any adsorbent material capable of
removing gas-phase constituents of mainstream smoke may be used in
the practice of the invention. Some examples are charred polymers,
engineered polymers, alumina, silica, clay and zeolites.
[0032] Any activated carbon material may be used in the practice of
the invention, including but not limited to carbon materials
derived from coal, tobacco material, peat, wood pulp, coconut
hulls, kapok fibers, cotton fibers, cotton linters, and the like.
Activated carbon materials of any degree of activation (surface
area) may be used according to the present invention. Preferably,
the activated carbon materials will have a degree of activation so
as to provide about 10 to about 50 weight percent butane pickup
(corresponding to about 25 to about 125 weight percent pickup of
carbon tetrachloride). More preferably, the activated carbon
material will provide about 60 weight percent pickup of carbon
tetrachloride. Any mesh size activated carbon is useful in the
practice of the invention. However, larger mesh size activated
carbons may provide advantages during the manufacture of the
cigarette. Preferred activated carbons are granular coconut carbons
with a mesh size of about 18.times.40 U.S such as coconut hull
based carbons available from Calgon Corp. as PCB, PCGB and GRC-11
and those available from PICA USA (Columbus, Ohio) as G278.
[0033] Applicants have surprisingly found that off-taste
suppressants of the present invention can, when used in critical
amounts, substantially reduce the off-taste associated with
carbon-containing cigarette filters without introducing any
significant additional foreign flavoring to the mainstream smoke so
that the cigarette has substantially the same taste as a non-carbon
filter cigarette. In other words, the off-taste suppressants of
this invention can substantially restore to the smoker the taste
normally associated with tobacco products which do not have carbon
containing filters.
[0034] Without wishing to be bound by any theory, it is believed
that the "off-taste" suppressants of the present invention function
by interacting with taste receptors on the tongue. Like most
biological processes, taste results from complex interactions of
one or more compounds with a receptor. Since taste receptors are
capable of recognizing both sweet and bitter tastes, the
interaction between different compounds can markedly alter or
suppress the taste associated with either compound alone.
[0035] Compounds eliciting a sweet taste are believed to share
similar structural characteristics as described by the "AH-B
Theory" of sweetness. See Shallenberger, R. S. and Acree, T. E.,
"Molecular Theory of Sweet Taste," Nature (London) 216(5114), p.
480 (1967). Specifically, sweet compounds have a proton donor
moiety comprising an electronegative atom, such as an oxygen or
nitrogen, with an attached hydrogen. In the "AH-B Theory" of taste
perception, "A" represents the electronegative atom. Accordingly,
the proton donor moiety can be described as "AH" where "H"
represents a hydrogen atom. Examples of AH proton donors include
hydroxyl groups, imines, amines, and methine groups. According to
the "AH-B Theory," a sweet compounds also has an electronegative
center (i.e., a proton acceptor) located about 3 .ANG. from the
hydrogen of the AH group. The electronegative center is represented
by "B" in this theory and can be, for example, an oxygen atom or a
nitrogen atom. The portion of a compound primarily responsible for
producing sweetness (the "glucophore") is represented as AH-B.
[0036] The taste receptors in the human tongue are comprised of
proteins. It has been theorized that these proteins are held
together by intermolecular hydrogen bonds between the carboxylate
group of glutamate (or aspartate) and the epsilon-NH.sub.3.sup.+ of
lysine. See Acree, T. E. "A Molecular Theory of Sweet Taste--Amino
Acids and Peptides," Proceedings of Joint Symposium on
Carbohydrate/Protein Interactions, Excelsior Springs, Mo.,
Carbohydrate/Oilseeds Division, American Association of Cereal
Chemists (1970). The carbonyl oxygen of the carboxylate and the
protons of the NH.sub.3.sup.+ group are about 3 .ANG. apart and are
ideally situated to serve as the receptor for an AH-B glucophore
through complimentary hydrogen bonding.
[0037] An additional component to molecular sweetness was
identified subsequent to the development of "AH-B Theory." It is
believed that lipophilic (hydrophobic) regions of a compound, if
located at a specific point in space in relation to the AH-B
moiety, may contribute to sweetness through interactions with
hydrophobic regions of the receptor. See R. Shallenberger and M.
Lindley, "A Lipophilic-Hydrophobic Component in the Stereochemistry
of Sweetness," Food Chem., vol. 2, 145-153, (1977). Thus, it is
theorized that there may be a tripartite interaction with taste
receptors of the form "AH-X-B" where "X" designates a lipophilic
region of a sweet compound. The lipophilic region "X", may function
to increase the lipoid solubility of the compound in the receptor
site to produce more intense or prolonged sweetness. Additionally,
the lipophilic site X may serve to direct that portion of a sweet
molecule representing AH-B into the proper orientation within the
receptor.
[0038] More recently, it was discovered that sweetness can be
produced by the interaction of more than one molecule with taste
receptors if the AH, B, and X components are provided separately by
the multiple molecules. See I. Shinoda and H. Okai, "Sweetness and
Bitterness Contributions of Structural Units of Aspartame and Some
Analogues," J. Agric. Food Chem., vol. 33, pp. 792-795 (1985). In
the study by Shinoda and Okai, it was found that bitter taste is
produced by molecules which have AH-X moieties but lack B moieties.
When compounds having B moieties are added to the tongue following
the addition of bitter AH-X compounds, the bitter taste associated
with the AH-X compound is converted to sweet taste. Further,
addition of compounds having X-B components to the tongue following
the addition of bitter AH-X compounds results in elimination of the
bitter taste.
[0039] Accordingly, in one aspect of the invention, the off-taste
suppressants are compounds that possess B or X-B moieties, either
alone or as part of AH-B and AH-X-B glucophores. In the case of
AH-B and AH-X-B glucophores, it is believed that only the B or X-B
units of these compounds combine with bitter AH-X compounds in the
taste receptors to eliminate or modify the bitter taste associated
therewith.
[0040] Non-limiting examples of AH-X-B and AH-B agents include
polyols, glycols, sugars, sugar-alcohols, oligosaccharides,
polysaccharides, amino acids, amino acid derivatives, di- and
tri-peptides, polypeptides, artificial sweeteners, and mixtures
thereof. Polyols include, for example, glycerol and propylene
glycol. Polysaccharides include cyclodextrins, dextrin,
hydrogenated oligosaccharides, hydrogenated starch hydrolysates,
polydextrose, and maltodextrin. Sugar alcohols include, for
example, erythritol, inositol, sorbitol, sorbose, mannitol, and
xylitol. Sugars include, for example, corn syrup, sucrose,
fructose, glucose, and honey. Amino acids and amino acid
derivatives include, for example, glycine and preferred artificial
sweeteners include aspartame.
[0041] Non-limiting examples of X-B and B agents include amides,
alcohol derivatives, esters, and lactones. Amides include, for
example, capsaicin and botanical extracts. Alcohol derivatives
include, for example, benzyl alcohol, gingerol, guaicol, santalol,
linalool and botanical extracts containing the said alcohol
derivatives. Esters include, for example, ethyl propionate.
Lactones include, for example, gamma-heptalactone.
[0042] It has been found that a mixture of mannitol and fructose,
preferably in a weight ratio in the range of about 1:3 to about
3:1, more preferably in about a 1:1 weight ratio, is particularly
effective as an off-taste suppressant for activated carbon.
[0043] Off-taste suppressants of the invention may include salts
that function to suppress perception of bitter tastes, which can be
used alone or, preferably, in combination with one or more AH-X-B,
AH-B, X-B or B agents. Non-limiting examples of salt off-taste
suppressants include alkali metal salts and alkaline earth metal
salts such as sodium salts and lithium salts. Sodium chloride,
sodium gluconate, monosodium glutamate, and the sodium salt of
glycine are example of sodium salts that may be used according to
the present invention. Preferred salt off-taste suppressants are
the sodium halide salts. Sodium chloride is the most preferred salt
off-taste suppressant.
[0044] Preferably, the salt suppresses off-taste without imparting
a perceptible salty taste to mainstream smoke. To this end, the
salt may constitute from about 0.1 to about 5 percent, and more
preferably about 1 percent, of the total weight of the activated
carbon and off-taste suppressant.
[0045] The optimal amount of off-taste suppressant for any given
amount of adsorbent may vary greatly depending on a number of
factors, including the nature and structure of the adsorbent, the
composition of the off-taste suppressant and consumer preferences.
The off-taste suppressant should be present in amounts sufficient
to significantly suppress, and preferably substantially eliminate,
adsorbent off-taste. At the higher end of the range, the weight
percent of off-taste suppressant applied to the adsorbent should be
selected to retain enough active carbon sites to achieve the
desired reduction of undesirable gas-phase constituents, preferably
without introducing additional flavor notes to the mainstream smoke
so that the original taste of the smoking article is substantially
restored. It will be recognized that one skilled in the art will be
able to optimize the weight percentages for any given off-taste
suppressant based on balancing these objectives.
[0046] Referring to the embodiment of FIG. 1, a cigarette 10 having
a tobacco rod 20 is provided with a filter 30 that can be secured
to tobacco rod 20 by tipping paper, not shown. In the embodiment of
FIG. 1, filter 30 is of the so-called plug-space-plug or triple
filter type. A first particulate filter component 34 at the buccal
end of the filter and a second particulate filter component 36
abutting the tobacco rod 20 are spaced apart to form a filter
cavity 38 therebetween. Filter cavity 38 contains a gas phase
filtering material 40 which, according to the invention, includes
an adsorbent having an off-taste suppressant applied thereto. The
triple filter including all three components is circumscribed by a
conventional paper wrapper 32. Cigarette 10 may be any length,
including but not limited to, 80 mm, 84 mm, and 99 mm.
[0047] Ventilation may be provided by one or more circumferential
rows of perforations, not shown, through the tipping paper. The
perforations may be located between the upstream and downstream
ends of the filter cavity 38 containing the adsorbent 40. As is
well-known, ventilation reduces the amount of mainstream smoke
reaching the smoker through dilution by ambient air and also tends
to increase filtration efficiency by decreasing the velocity of
mainstream smoke upstream of the perforations and thereby
increasing its residence time in the filter.
[0048] Filter components 34 and 36 may be formed from any media
capable of filtering particulates from the mainstream smoke.
Non-limiting examples of suitable media include webbed or fibrous
polyolefins and cellulosics. Cellulosics may include paper and
cellulose acetate fiber. Preferably, filter components 34 and 36
are plugs of cellulose acetate tow well known in the art. Filter
components 34 and 36 may contain a plasticizer such as triacetin
for binding the fibers together. The plasticizer may have an
affinity for particulate matter and further contribute to the
efficiency of the tow for reducing particulate matter in the
mainstream smoke. The use of plasticizers, particularly triacetin,
as a binder in filter tows is well known in the art.
[0049] In a preferred embodiment, cigarette 10 is 84 mm long and
downstream tow 34 is 10 mm in length. The cavity 38 formed between
tows 34 and 36 ranges from about 3 mm to about 8 mm in length, and
is preferably between about 5 nun and about 6 mm in length. In an
embodiment where cavity 38 is 5 mm in length, the upstream tow 36
is 10 nun in length. In another embodiment, cavity 38 is 6 mm in
length and upstream tow 36 is 9 mm in length. Ventilation is
provided in filter cavity 38 by perforations located 14.5 mm from
the buccal end of downstream tow 34.
[0050] In another preferred embodiment, cigarette 10 is 99 mm long
and downstream tow 34 is 10 mm in length. The cavity 38 formed
between tows 34 and 36 ranges from about 3 mm to about 8 mm in
length, and is preferably between about 5 nun and about 6 mm in
length. In an embodiment where cavity 38 is 5 nun in length, the
upstream tow 36 is 12 mm in length. In another embodiment, cavity
38 is 6 mm in length and upstream tow 36 is 11 nun in length.
Ventilation is provided in filter cavity 38 by perforations located
14.5 mm from the buccal end of downstream tow 34.
[0051] In accordance with another aspect of the invention, it is
contemplated that chemisorbents may be used in conjunction with
adsorbents treated with off-taste suppressant to provide filters
having enhanced gas reduction capability. Chemisorbents include,
but are not limited to, ion exchange resins, preferably selected
from polystyrenes and derivatives thereof. Preferred ion exchange
resins are macroporous beads functionalized with primary amine
groups such as Purolite A-143 and Purolite A-109. Polyamine
functionalized beads such as Rohm & Haas Amberlite IRA-95, and
weak base functionalized beads such as Rohm & Haas Duolite A-7
may also be used. The most preferred ion exchange resin is Purolite
A-109, which is a primary amine functionalized polystyrene
crosslinked with divinylbenzene in the form of macroporous
spherical beads.
[0052] The amount of adsorbent should be selected to achieve the
most effective gas phase reduction within the limits of the smoking
article. In the embodiment of FIG. 1, it is preferred that the
cavity 38 is completely filled with gas phase filtering material
40. More preferably, cavity 38 is filled with about 150 mg of
activated carbon in embodiments having a 6 mm filter cavity and 125
mg in embodiments having a 5 mm cavity.
[0053] In the triple filter embodiment of FIG. 1, the chemisorbent
may be present in filter cavity 38 in admixture with the adsorbent.
When present, the chemisorbent is preferably in about a 25:75 to
75:25 wt./wt. admixture with the adsorbent.
[0054] When the adsorbent is present in admixture with a
chemisorbent material, there will be significantly less adsorbent
present for the same size cavity. For example, a gas phase
filtering material comprising 25 weight % treated activated carbon
and 75 weight % ion exchange resin filling a 6 mm cavity may only
contain about 10 to about 31 mg of activated carbon due to the much
lower density of the resin. Similarly, a 5 mm cavity filled with
gas phase filtering material comprising 25 weight % treated
activated carbon and 75 weight % ion exchange resin may only
contain about 8 to about 27 mg of activated carbon.
[0055] Although ion exchange resins themselves have an undesirable
characteristic off-taste, it has surprisingly been discovered that
smoking articles having filters of the present invention which
include ion exchange resins have substantially reduced resin
off-taste. It is believed that certain volatile components of the
ion exchange resin which produce the characteristic off-taste, such
as monomers and solvents, are adsorbed by the activated carbon and
thus removed from the mainstream smoke. For this reason, in
embodiments where the ion exchange resin is separately positioned
from and not in admixture with the adsorbent, it is desirable to
position the adsorbent downstream of the resin. Such an embodiment
is depicted in FIG. 2. In FIG. 2, the adsorbent treated with
off-taste suppressant 40 is downstream of the chemisorbent 42. The
chemisorbent may be disposed in a cavity, as in the FIG. 2
embodiment, or may be present as a dispersion in a fibrous tow to
form a "dalmation" filter component.
[0056] A variety of methods may be employed to apply the off-taste
suppressants to the adsorbent such as activated carbon. In one
method, an aqueous or ethanolic solution of the off-taste
suppressant is added to the activated carbon followed by
evaporation with optional heating. In a second, preferred method,
an aqueous solution of the off-taste suppressant is sprayed onto
activated carbon without a further drying step. A baffle mixer
operating between about 150-165.degree. C. with about 30-60 minute
impregnation cycles may by used to coat about 400-1000 pounds of
activated carbon with off-taste suppressant. Advantageously, it has
been found that lesser quantities of off-taste suppressant may be
used to suppress carbon off-taste with this method of application
as compared to the evaporation technique. It has been found that
the moisture from the off-taste suppressant can be used
advantageously to both minimize static buildup during cigarette
manufacture and pre-equilibrate the moisture in the activated
carbon and tobacco rod.
[0057] A preferred embodiment of the invention employs a triple,
plug-space-plug filter as in FIG. 1, having a 6 mm cavity filled
with an admixture of 18.times.40 U.S. mesh granular coconut
activated carbon (PICA, USA) and ion exchange resin A109 (Purolite
USA). The activated carbon is treated with an off-taste suppressant
composition consisting of a 46:46:8 wt. % mixture of mannitol,
fructose, and sodium chloride by a baffle spray coating technique.
The off-taste suppressant composition is present on the carbon at
11 weight percent of the total weight of activated carbon and
off-taste suppressant. The admixture of treated activated carbon
and ion exchange resin consists of about 25 weight % treated
activated carbon and about 75 weight % resin. When cavity 38 is 5
mm in length and fully charged with the admixture, there will be
about 8 to about 27 mg of treated carbon and about 35 to about 60
mg of resin present. When cavity 38 is 6 mm in length and fully
charged with the admixture, there will be about 10 to about 31 mg
of treated carbon and about 43 to about 70 mg of resin present. In
another preferred embodiment, the admixture of treated activated
carbon and ion exchange resin consists of about 50 weight % treated
activated carbon and about 50 weight % resin. When cavity 38 is 5
mm in length and fully charged with this admixture, there will be
about 19 to about 66 mg of treated carbon and about 23 to about 54
mg of resin present. When cavity 38 is 6 mm in length and fully
charged with this admixture, there will be about 23 to about 78 mg
of treated carbon and about 28 to about 64 mg of resin present in
this embodiment. In both embodiments, a 10 mm long conventional
plug of fiber tow is located at the buccal end of the filter and a
row of ventilation openings in the tipping paper encircle the
filter about 141/2 mm from its buccal end.
[0058] It is to be understood that the invention may be used in
flavored smoking articles. The preferred flavoring agent is
menthol. When flavored cigarettes are desired, flavoring agents may
be incorporated into, for example, the tobacco, wrapping paper,
plug wrap, and filter tows. In the preferred practice of the
invention, no flavoring agents are added to the filter tows.
[0059] When flavored cigarettes are desired, flavoring agents may
be incorporated into, for example, the tobacco, wrapping paper,
plug wrap, and filter tows. In the preferred practice of the
invention, no flavoring agents are added to the filter tows.
[0060] Any smokeable material may be used with the present
invention. Examples of suitable smokeable tobacco materials
include, but are not limited to, flue-cured, Burley, Turkish,
expanded tobacco, and reconstituted tobacco. Other tobacco
materials suitable for use in the present invention are described
in U.S. Pat. No. 5,404,890 (Gentry et. al.) which is hereby
incorporated by reference. A preferred tobacco is low
tobacco-specific nitrosoamine (TSNA) tobacco.
[0061] The wrapping papers and tipping papers used in the practice
of the invention may be any of the papers known in the art,
including low-sidestream paper and reduced ignition propensity
paper such as those disclosed in U.S. Patent Application Pub. Nos.
20020074010 (Snaidr et al), 20020129824 (Hammersmith et al.),
20020139381 (Peterson et al.), 20020179105 (Zawadzki et al),
20020179106 (Zawadzki et al.), and 20020185143 (Crooks et al.) and
U.S. Pat. Nos. 5,271,419 (Arzonico et al.), 5,878,753 (Peterson et
al), 5,878,754 (Peterson et al), 6,129,087 (Wallace et al.), and
6,371,127 (Snaidr et al.), which are hereby incorporated by
reference.
[0062] Advantageously, it has been found that the filters of the
present invention provide the additional benefit of increasing the
"freshness" of cigarettes. It is postulated that tobacco loses
moisture over time, resulting in increased release of gas phase
components such as aldehydes, imparting a stale, harsh, or bitter
taste to mainstream smoke. See U.S. Pat. No. 2,063,014 (Allen).
Prior approaches to overcoming the undesirable taste associated
with tobacco that has been stored for long periods of time involve
covering-up the undesirable taste with flavoring agents. See, U.S.
Pat. No. 3,144,024 (Eichwald et al.). In contrast, the filters of
the present invention are capable of removing gas phase
constituents of mainstream smoke, thereby diminishing the
undesirable organoleptic perception of aged tobacco without the
addition of flavoring agents. Accordingly, the cigarettes of the
present invention may have an increased shelf life.
[0063] FIG. 3 illustrates another embodiment of the invention. In
addition to the conventional buccal end particulate filter
component 34, which may be a plug of fiber tow, filter 50 has a
"dalmation" filter component 52. Dalmation filter component 52 is a
conventional plug of particulate filter material impregnated with a
gas-phase adsorbent, preferably activated carbon granules, to which
off-taste suppressant according to the invention has been applied.
For example, activated carbon granules may be dispersed within a
cellulose acetate tow or a paper filter material, as described in
U.S. Pat. Nos. 6,257,242 B1 (Stavridis), 5,622,190 (Arterbery et
al.), 5,568,819 (Gentry et al.), 3,101,723 (Seligman et al.), which
are hereby incorporated by reference.
[0064] The present invention is not limited to the filter designs
described above. It is contemplated that other filter arrangements
are suitable for use with the present invention, including but not
limited to those described in European Patent Application No.
579,410 and U.S. Pat. Nos. 5,568,819 (Gentry et al.), 5,365,951
(Arterbery et al.), 5,067,499 (Banerjee et al.), 4,881,556
(Clearman et al.), 4,357,950 (Berger et al.), 3,894,545 (Crellin et
al.), which are hereby incorporated by reference. It will be
appreciated by one skilled in the art that certain modifications
and variations of the above described embodiments are within the
scope of the invention.
[0065] The following non-limiting examples are provided to
illustrate usage of the invention.
EXAMPLES 1-10
[0066] In Examples 1-7 and 10, the lengths of the filter cavities
provided are estimated based on the approximate density of the
treated activated carbon samples. In a fully loaded condition there
will be approximately 25 mg of treated activated carbon per
millimeter of cavity length.
[0067] Cigarettes designated as ventilated in the following
Examples contained a circumferential row of perforations somewhere
along the length of the filter cavity between its upstream and
downstream ends.
Example 1
[0068] Activated coconut carbon was treated with various materials
as listed in Table 1. For all samples listed in this example, PCB
(20.times.50 mesh) activated coconut carbon supplied by Calgon
Carbon Corporation (Pittsburgh, Pa.) was used.
TABLE-US-00001 TABLE 1 Application Application Material # Treatment
Source ** (% wt/total wt) (mmole/gram carbon) 1-1 Glucosamine
hydrochloride Cat #G220-6; Aldrich 20.0 1.16 1-2 Glucose
monohydrate Cat #49158; Fluka 18.7 1.16 1-3 Lactose monohydrate Cat
#61339; Fluka 29.5 1.16 1-4 Maltose monohydrate Cat #63419; Fluka
29.5 1.16 1-5 Sorbitol Cat #S375-5; Aldrich 4.1 1.16 1-6 Mannitol
Cat #M-9647; Sigma 17.2 1.14 1-7 Fructose Cat #15760; Riedel-de
Haen 17.2 1.15 1-8 Inositol Cat #I6652; Aldrich 17.2 1.16 1-9
Tapioca Dextrin Crystal Tex 627; National Starch 20.0 -- 1-10
Erythritol Cat #E-7500; Sigma 12.6 1.18 1-11 Calorie Free Sweetener
* Great Value Brand; WallMart 18.7 -- 1-12 Sucrose Cat #84097;
Fluka 28.2 1.15 1-13 Chitosan oligosaccharide lactate Cat
#52,368-2; Aldrich 16.9 -- 1-14 Maltodextrin Lodex-10; Mother
Murphy's 19.9 -- 1-15 Hydroxypropyl-.beta.-cyclodextrin Cat
#85,608-8; Aldrich 19.9 -- * Contains: glucose, maltodextrin, and
aspartame; -- = not determined; ** Aldrich = Aldrich Chemical
Company (Milwaukee, WI); National Starch = National Starch
(Bridgewater, NJ); Sigma Chemical Company (Milwaukee, WI);
Riedel-de Haen = Fluka Riedel-de Haen (Milwaukee, WI); WallMart =
WallMart Stores Incorporated (Bentonville, AR); Fluka = Fluka
Chemical Corporation (Milwaukee, WI); Mother Murphy's = Mother
Murphy's Laboratories Incorporated (Greensboro, NC).
[0069] The carbon material was treated according to the following
general procedure. Each treating agent listed in Table 1 was
dissolved in water. The resulting solution was applied to the
untreated carbon. Sufficient treatment material was added to the
water to yield the final application as listed in Table 1.
Generally, a water to carbon ratio of approximately 1.8:1 was used.
The wet carbon was then dried at approximately 105.degree. C. for
approximately 12 hours.
[0070] 99-millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared as shown in Table 2. After drying,
approximately 150 milligrams of the various treated carbons were
added to the cavities, which were approximately 6 mm long. Sample
1-C was loaded with approximately 150 mg. Of the untreated carbon.
These cigarettes were tested against a control cigarette, (1-CTL,
Table 2) having a single cellulose acetate plug with no carbon.
TABLE-US-00002 TABLE 2 Micrograms aldehyde/cigarette (% reduction
versus 1-CTL) Cigarette # Material # Formaldehyde Acetaldehyde
Acrolein Propionaldehyde Crotonaldehyde 1-CTL * -- 57.6 1187.8
152.5 100.3 25.3 1-C ** PCB 38.6 (33.0) 161.7 (86.4) 8.4 (94.5) 8.1
(91.9) 0.7 (97.2) 1-1C 1-1 39.0 (32.2) 769.6 (35.2) 39.2 (74.3)
44.0 (56.2) 2.6 (89.6) 1-2C 1-2 40.9 (28.9) 418.9 (64.7) 19.7
(87.1) 19.5 (80.5) 1.7 (93.4) 1-3C 1-3 47.4 (17.6) 1090.8 (8.2)
117.4 (23.1) 87.3 (12.9) 14 (44.6) 1-4C 1-4 47.7 (17.2) 1105.0
(7.0) 129.7 (15.0) 91.8 (8.5) 15.9 (37.3) 1-5C 1-5 39.9 (30.8)
393.6 (66.9) 21.2 (86.1) 19.6 (80.5) 1.6 (93.7) 1-6C 1-6 40.1
(30.3) 274.7 (76.9) 17.7 (88.4) 16.1 (84.0) 3.5 (86.1) 1-7C 1-7
36.5 (36.7) 164.2 (86.2) 8.3 (94.6) 7.8 (92.2) 1.8 (92.8) 1-8C 1-8
41.9 (27.2) 165.5 (86.1) 11.8 (92.3) 10.3 (89.7) 2.6 (89.7) 1-9C
1-9 56.9 (1.1) 917.3 (22.8) 103.2 (32.4) 69.4 (30.8) 18.1 (28.5)
1-10C 1-10 44.7 (22.3) 272.1 (77.1) 15.9 (89.6) 13.1 (86.9) 0.5
(97.9) 1-11C 1-11 42.9 (25.5) 444.8 (62.6) 30.2 (80.2) 27.5 (72.6)
2.2 (91.2) 1-12C 1-12 46.4 (19.5) 898.2 (24.4) 78.5 (48.5) 63.1
(37.0) 11.4 (55.0) 1-13C 1-13 46.3 (19.5) 729.4 (38.6) 73.6 (51.7)
55.7 (44.5) 15.0 (40.8) 1-14C 1-14 45.6 (20.8) 674.1 (43.3) 58.5
(61.6) 50.5 (49.7) 2.4 (90.4) 1-15C 1-15 46.0 (20.1) 740.0 (37.7)
76.4 (49.9) 59.4 (40.7) 4.1 (83.7) PCB = untreated PCB (20 .times.
50 mesh) activated coconut carbon supplied by Calgon Carbon
Corporation (Pittsburgh, PA); * Aldehyde contents are the average
of triplicate tests; ** Aldehyde contents are the average of
duplicate tests; -- = not applicable.
[0071] Cigarettes were analyzed for whole smoke carbonyl content.
Whole smoke carbonyl content and carbonyl reduction data is given
in Table 2. Cigarette types as listed in Table 2 were smoked and
evaluated for taste properties. Cigarette type 1-C containing
untreated PCB carbon was found to have a chalky, unpleasant, bitter
and drying taste. Cigarettes types 1-1C through 1-8C, 1-10C, and
1-15C were found to have suppressed carbon off-taste versus type
1-C. For cigarettes types 1-1C through 1-8C, 1-10C, and 1-15C, the
treatment conferred approximately 30 to 50% suppression of the base
carbon off-taste. Cigarette types 1-9C, 1-11C, 1-12C, 1-13C all
displayed less than about 30% suppression of the base carbon
off-taste. Significantly, the treated carbon material in cigarette
types 1-6C (mannitol treatment) and 1-7C (fructose treatment)
showed high carbonyl removal efficiencies and the greatest
suppression of base carbon off-taste. These results demonstrate
that activated carbon treated with certain sugars and polyols is
effective in reducing undesirable gas phase constituents of
mainstream smoke while suppressing the off-taste associated with
activated carbon adsorbents.
Example 2
[0072] The following test was conducted to determine the efficacy
of various amino acids as off-taste suppressants for use in the
present invention. Activated coconut carbon was treated with
various materials as listed in Table 3. For all samples listed in
this example, PCB (20.times.50 mesh) activated coconut carbon
supplied by Calgon Carbon Corporation (Pittsburgh, Pa.) was
used.
TABLE-US-00003 TABLE 3 Application Application Material # Treatment
Source * (% wt/total wt) (mmole/gram carbon) 2-1 Asparagine Cat
#A9,300-3; Aldrich 8.49 0.70 2-2 Glutamine Cat #G-3126; Sigma 9.45
0.71 2-3 Glycine Cat #G620-1; Aldrich 4.84 0.68 * Aldrich = Aldrich
Chemical Company (Millwaukee, WI); Sigma Chemical Company
(Millwaukee, WI).
[0073] The activated carbon was treated according to the following
general procedure. Each treatment material listed in Table 3 was
dissolved in water. Then the resulting solution was applied to the
untreated carbon. Sufficient treatment material was added to the
water to yield the final application as listed in Table 3.
Generally, a water to carbon ratio of approximately 2:1 was used.
The wet carbon was then dried at approximately 90.degree. C. for
approximately 5 hours.
[0074] 99 millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared. After drying, approximately 150
milligrams of the treated carbons were loaded into cavities
approximately 6 mm. Sample 2-C was loaded with approximately 150
mg. Of the untreated carbon. These cigarettes were tested against a
control cigarette (2-CTL, Table 4) having a single cellulose
acetate plug with no carbon.
TABLE-US-00004 TABLE 4 Micrograms aldehyde/cigarette (% reduction
versus 2-CTL) Cigarette # Material # Formaldehyde Acetaldehyde
Acrolein Propionaldehyde Crotonaldehyde 2-CTL -- 46.0 1077.0 131.2
88.0 25.4 2-C * PCB 38.6 (16.0) 161.7 (85.0) 8.4 (93.6) 8.1 (90.8)
0.7 (97.2) 2-1C 2-1 40.1 (12.8) 140.9 (86.9) 7.3 (94.4) 9.3 (89.4)
1.4 (94.5) 2-2C 2-2 33.8 (26.5) 184.7 (82.9) 7.3 (94.4) 9.8 (88.9)
1.9 (92.5) 2-3C 2-3 32.4 (29.5) 114.3 (89.4) 5.1 (96.1) 7.9 (91.0)
ND PCB = untreated PCB (20 .times. 50 mesh) activated coconut
carbon supplied by Calgon Carbon Corporation (Pittsburgh, PA); *
Aldehyde contents are the average of duplicate tests; -- = not
applicable; ND = not detected.
[0075] Cigarettes were analyzed for whole smoke carbonyl content.
Whole smoke carbonyl content and carbonyl reduction data is given
in Table 4. Cigarette types as listed in Table 4 were smoked and
evaluated for taste properties. Cigarette type 2-C, containing
untreated PCB carbon, was found to have a chalky, unpleasant,
bitter and drying taste. Cigarettes types 2-1C, 2-2C, and 2-3C were
found to have suppressed carbon off-taste versus type 2-C. For
cigarettes types 2-1C, 2-2C, and 2-3C the treatment conferred
approximately 20% suppression of the base carbon off-taste. These
results illustrate that while amino acids are effective in reducing
the perceived carbon off-taste, the degree of suppression is not as
large as that exhibited by the polyols and sugars described in
Example 1.
Example 3
[0076] For this example, PICACARB (12.times.40 mesh) activated
anthracite carbon supplied by PICA USA (Columbus, Ohio) was treated
with mannitol and fructose. Mannitol (Cat #25,409-6, Aldrich
Chemical Company; Milwaukee, Wis.), 1.07 grams, and fructose (Cat
#15760, Riedel-de Haen; Milwaukee, Wis.), 1.08 grams, were
dissolved in 25.33 grams of water. The solution was then applied to
10.01 grams of PICACARB anthracite carbon (PICA USA; Columbus,
Ohio). The wet carbon was then dried at approximately 90.degree. C.
for approximately 12 hours.
[0077] 84 millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared. After drying, approximately 150
milligrams of treated carbon were loaded into the cavity of one
cigarette, which was approximately 6 mm long (Cigarette type 3-1C,
Table 5). Another cigarette having approximately a 3 mm cavity was
loaded with approximately 75 milligrams of untreated PICACARB
carbon (Cigarette type 3-C, Table 5). These cigarettes were tested
against a control cigarette (3-CTL, Table 5) containing single
cellulose acetate plugs having no carbon.
TABLE-US-00005 TABLE 5 Micrograms aldehyde/cigarette (% reduction
versus 3-CTL) Cig. # Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde 3-CTL 31.4 913.4 110.2 70.3 28.1 3-C
37.9 (-20.7) 709.8 (22.3) 52.2 (52.6) 40.8 (42.0) 7.1 (74.7) 3-1C
39.9 (-27.1) 626.5 (31.4) 43.5 (60.5) 36.7 (47.8) 7.2 (74.4)
[0078] Mainstream smoke carbonyl content and carbonyl reduction
data is given in Table 5. The taste properties of cigarette types
3-C and 3-1C were evaluated. Cigarette type 3-C, containing
untreated anthracite carbon, was found to have a chalky,
unpleasant, harsh, and drying taste. Significantly, it was found
that although the carbonyl contents of cigarette types 3-C and 3-1C
were similar, the carbon off-taste was significantly suppressed in
cigarette sample 3-1C relative to cigarette sample type 3-C.
Example 4
[0079] For this example, G278 (18.times.40 mesh) activated coconut
carbon supplied by PICA USA (Columbus, Ohio) was treated with
mannitol and fructose. Mannitol (Cat #M-9647, Sigma Chemical
Company; Milwaukee, Wis.), 1.01 grams, and fructose (Cat #15760,
Riedel-de Haen; Milwaukee, Wis.), 1.01 grams, were dissolved in
17.51 grams of water. The solution was then applied to 10.01 grams
G278 coconut carbon (PICA USA; Columbus, Ohio). The wet carbon was
then dried at approximately 90.degree. C.
[0080] 99 millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared. After drying, approximately 180
milligrams of the treated carbon were loaded into the cavities,
which were approximately 7 millimeters long (Cigarette type 4-1C,
Table 6). Similar cigarettes containing approximately 150
milligrams of untreated G278 carbon (Cigarette type 4-C, Table 6)
were also prepared. These cigarettes were tested against control
cigarettes (4-CTL, Table 6), containing single cellulose acetate
plugs having no carbon.
TABLE-US-00006 TABLE 6 Micrograms aldehyde/cigarette (% reduction
versus 4-CTL) * Cig. # Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde 4-CTL 51.1 993.6 134.8 84.5 19.8 4-C
39.0 (23.7) 200.5 (79.8) 13.6 (89.9) 12.4 (85.3) 0.7 (96.4) 4-1C
43.8 (14.4) 454.6 (54.5) 33.0 (75.5) 27.9 (67.0) 3.7 (81.2) *
Aldehyde contents are the average of duplicate tests.
[0081] Mainstream smoke carbonyl content and carbonyl reduction
data is given in Table 6. The taste properties of cigarette types
4-CTL, 4-C and 4-1C were evaluated. Cigarette type 4-C, containing
untreated G278 carbon, was found to have a chalky and drying taste.
Also for cigarette type 4-C, the tobacco and menthol taste levels
were significantly decreased relative to control cigarette type
4-CTL. Cigarette type 4-1C was found to have significantly
suppressed base off-taste. Unexpectedly, the applicants discovered
cigarette type 4-1C had increased tobacco and menthol taste
relative to sample type 4-C.
Example 5
[0082] Activated coconut carbon was treated with various materials
as listed in Table 7. For all samples listed in this example, G278
(18.times.40 mesh) activated coconut carbon supplied by PICA USA
(Columbus, Ohio) was used.
TABLE-US-00007 TABLE 7 Application Material # Treatment Source * (%
wt/total wt) 5-1 Glycerol Cat #G153-1; Fisher 16.8 5-2 Glycerol Cat
#G153-1; Fisher 9.3 5-3 Glycerol Cat #G153-1; Fisher 2.4 5-4
Sorbitol Cat #S375-5; Aldrich 28.7 5-5 Sorbitol Cat #S375-5;
Aldrich 16.8 5-6 Mannitol Cat #M-9647; Sigma 28.8 5-7 Mannitol Cat
#M-9647; Sigma 16.9 5-8 Mannitol Cat #M-9647; Sigma 4.9 5-9
Propylene Glycol Production item 15.2 5-10 Xylitol Cat #85,158-2;
Aldrich 15.0 * Aldrich = Aldrich Chemical Company (Milwaukee, WI);
Sigma = Sigma Chemical Company (Milwaukee, WI); Fisher = Fisher
Scientific (Fair Lawn, NJ).
[0083] The carbon material was treated according to the following
general procedure. Each treatment material listed in Table 7 was
dissolved in water. Then the resulting solution was applied to
untreated carbon. Sufficient treatment material was added to the
water to yield the final application as listed in Table 7.
Generally, the water to carbon ratio of approximately 1.8:1 was
used. The wet carbon was then dried at approximately 105.degree. C.
for approximately 12 hours.
[0084] 84 millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared. After drying, approximately 100
milligrams of the treated carbons were loaded onto the cavities,
which were approximately 4 millimeters long. Cigarette type 5-C was
prepared using 50 milligrams untreated G278 carbon. These
cigarettes were tested against control cigarette (5-CTL, Table 8)
having a single cellulose acetate plug with no carbon.
TABLE-US-00008 TABLE 8 Micrograms aldehyde/cigarette (% reduction
versus 5-CTL) * Cigarette # Material # Formaldehyde Acetaldehyde
Acrolein Propionaldehyde Crotonaldehyde 5-CTL -- 22.6 701.8 64.0
58.4 26.7 5-C G278 19.1 (15.6) 332.2 (52.7) 19.6 (69.5) 19.2 (67.1)
10.1 (62.0) 5-1C 5-1 17.5 (22.4) 286.6 (59.2) 13.1 (79.5) 17.4
(70.3) 8.4 (68.4) 5-2C 5-2 18.7 (17.3) 193.4 (72.4) 9.5 (85.2) 11.3
(80.6) 5.6 (78.8) 5-3C 5-3 16.3 (27.9) 111.5 (84.1) 6.6 (89.7) 8.3
(85.8) 4.5 (83.1) 5-4C 5-4 24.4 (-8.1) 698.2 (0.5) 59.9 (6.5) 54.5
(6.7) 19.6 (26.3) 5-5C 5-5 19.4 (14.1) 365.7 (47.9) 21.0 (67.2)
22.6 (61.4) 8.7 (67.3) 5-6C 5-6 19.2 (15.0) 578.9 (17.5) 39.2
(38.7) 43.8 (24.9) 21.3 (20.2) 5-7C 5-7 18.8 (17.0) 361.4 (48.5)
18.9 (70.5) 22.8 (61.0) 13.1 (50.9) 5-8C 5-8 17.4 (22.8) 185.4
(73.6) 10.5 (83.5) 11.4 (80.5) 8.2 (69.3) 5-9C 5-9 19.9 (12.1)
298.2 (57.5) 15.0 (76.5) 14.6 (75.1) 5.9 (77.7) 5-10C 5-10 14.5
(35.6) 138.7 (80.2) 7.8 (87.8) 7.2 (87.7) 3.0 (88.8) G278 = 50
milligrams/cigarette, G278 (18 .times. 40 mesh) activated coconut
carbon supplied by PICA USA (Columbus, OH) * Aldehyde contents are
the average of duplicate tests; -- = not applicable.
[0085] Cigarettes were analyzed for whole smoke carbonyl content.
Whole smoke carbonyl content and carbonyl reduction data is given
in Table 8. Cigarette types as listed in Table 8 were smoked and
evaluated for taste properties. The results are given in Table 9
below. Cigarette type 5-C, containing untreated G278 carbon, was
found to have a chalky, unpleasant, bitter, and drying taste.
Overall, polyol treatments were found to significantly suppress
carbon off-taste with the level of suppression dependent upon
amount and type of polyol added. See Table 9. Significantly, the
treated carbon material used to prepare cigarette types 5-7C
(mannitol treatment) and 5-10C (xylitol treatment) showed high
carbonyl removal efficiencies and the greatest suppression of
carbon off-taste.
TABLE-US-00009 TABLE 9 Carbon Off-Taste Cigarette # Material #
Suppression (%) 5-C G278 0 5-1C 5-1 40 5-2C 5-2 30 5-3C 5-3 15 5-5C
5-5 45 5-6C 5-6 75 5-7C 5-7 50 5-8C 5-8 20 5-9C 5-9 35 5-10C 5-10
55 G278 = G278 (18 .times. 40 mesh) activated coconut carbon
supplied by PICA USA (Columbus, OH).
Example 6
[0086] Activated coconut carbon was treated with various materials
as listed in Table 10. For all samples listed in this example, G278
(18.times.40 mesh) activated coconut carbon supplied by PICA USA
(Columbus, Ohio) was used.
TABLE-US-00010 TABLE 10 Material Application (grams # Treatment *
treatment/grams carbon) 6-1 Fructose, Mannitol 0.0919, 0.0923 6-2
Fructose, Mannitol, Sodium Chloride 0.0926, 0.0930, 0.0117 6-3
Fructose, Mannitol, Sodium Chloride 0.0919, 0.0924, 0.0530 *
Fructose, Cat #14,092-9, Aldrich Chemical Company (Milwaukee, WI);
Mannitol, Cat #25,409-6, Aldrich Chemical Company (Milwaukee, WI);
Sodium Chloride, Non-iodized, Morton International, Morton Salt
(Chicago, IL).
[0087] The carbon material was treated according to the following
general procedure. Treatment material was dissolved in water. Then
the resulting solution was applied to untreated carbon. Sufficient
treatment material was added to the water to yield the final
applications as listed in Table 10. Generally, a water to carbon
ratio of approximately 1.7:1 was used. The wet carbon was then
dried at approximately 60.degree. C. for approximately 36
hours.
[0088] 99 millimeter cigarettes having ventilated filters like that
of FIG. 1 were prepared. After drying, approximately 100 milligrams
of the treated carbons were loaded into the cavities, which were
approximately 4 millimeters long. These cigarettes were tested
against a control cigarette type (6-CTL, Table 11) having a single
cellulose acetate plug with no carbon.
[0089] Cigarettes were analyzed for whole smoke carbonyl content.
Whole smoke carbonyl content and carbonyl reduction data is given
in Table 11.
TABLE-US-00011 TABLE 11 Micrograms aldehyde/cigarette (% reduction
versus 6-CTL) Cig. # Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde 6-CTL 20.5 640.4 71.5 56.2 16.5 6-1C
18.1 (11.7) 302.5 (52.8) 18.3 (74.4) 20.1 (64.2) 8.5 (48.4) 6-2C
18.0 (12.2) 287.7 (55.1) 16.6 (76.8) 18.5 (67.1) 6.4 (60.9) 6-3C
21.0 (-2.6) 414.5 (35.3) 29.4 (58.9) 30.0 (46.7) 8.9 (45.8) G278 =
50 milligrams/cigarette, G278 (18 .times. 40 mesh) activated
coconut carbon supplied by PICA USA (Columbus, OH) * Aldehyde
contents are the average of duplicate tests.
[0090] Cigarette types as listed in Table 11 were smoked and
evaluated for taste properties. Unexpectedly, applicants discovered
that the presence of sodium chloride in the treatment mixture
significantly enhances carbon off-taste suppression. Cigarette type
6-2C (fructose/mannitol/sodium chloride) was found to have 80%
carbon off-taste suppression while type 6-1C (fructose/mannitol)
was found to have 60% carbon off-taste suppression.
Example 7
[0091] Three different off-taste suppression compositions were
tested using a mixer, concentrated aqueous solutions of fructose
(Krystar 300, Tate & Lyle, A. E. Staley Manufacturing Company;
Decatur, Ill.) and mannitol (Mannitol, USP, Welco) were
spray-coated onto samples of G278 (18.times.40 mesh) activated
coconut carbon supplied by PICA USA (Materials 7-1 and 7-2, Table
12 and Table 13). An aqueous solution of fructose (Krystar 300,
Tate & Lyle, A. E. Staley Manufacturing Company; Decatur,
Ill.), mannitol (Mannitol, USP, Welco), and sodium chloride
(Canning and Pickling Salt, Morton Salt Company; Chicago, Ill.) was
similarly applied to G278 carbon (Material 7-3, Table 12 and Table
13).
TABLE-US-00012 TABLE 12 Carbon Fructose Mannitol NaCl Water
Material # (pounds) (pounds) (pounds) (pounds) (pounds) 7-1 400
29.3 29.3 -- 58.7 7-2 400 21.8 21.8 -- 57 7-3 400 21.8 21.8 4.0 57
Carbon = G278 (18 .times. 40 mesh) activated coconut carbon
supplied by PICA USA (Columbus, OH); Fructose = Kyrstar 300 (Tate
& Lyle, A. E. Staley Manufacturing Company; Decatur, IL);
Mannitol = Mannitol, USP (Welco); NaCl = Sodium chloride, Canning
and Pickling Salt (Morton Salt; Chicago, IL); Water = Tap water; --
= not applicable.
TABLE-US-00013 TABLE 13 Material Activity Activity Moisture Density
(as is, # (dry) (as is) (%) grams/milliliter) 7-1 48.3 33.7 16.5
0.711 7-2 45.4 32.3 16.9 0.707 7-3 -- 38.0 13.0 0.691 Moisture
content determined by loss of weight on drying at 105.degree. C.
for 4 hours; Activity = CCl.sub.4 number = 2.55 .times. butane
activity determined by ASTM method D5742-95 "Standard Test Method
for Determination of Butane Activity of Activated Carbon"; Density
determined by ASTM method D2854 "Test Method for Apparent Density
of Activated Carbon"; As is = as prepared; Dry = after drying at
105.degree. C. for 4 hours.
[0092] 84 millimeter cigarettes having ventilated filters like that
of FIG. 1 were prepared. The cavities of these cigarettes were
loaded with the treated carbon to produce samples 7-1C, 7-2C, 7-3C
and 7-4C (Table 14). Three additional sample cigarettes 7-1C, 7-2C
and 7-3C were loaded with untreated carbon (Table 14). These
cigarettes were tested against control cigarettes (7-CTL, Table 14)
having a single cellulose acetate plug with no carbon.
[0093] Carbonyl removal data for treated and untreated carbon types
are listed in Table 14. Cigarette type 7-C2 containing 50 mg of
untreated carbon (Table 14) gave unacceptably bitter carbon
off-taste, whereas cigarette type 7-3C containing 100 mg of
fructose/mannitol/sodium chloride-treated carbon (Table 14) was
found to have about 80% suppression of carbon off-taste. Both
cigarette types 7-C2 and 7-3C displayed similar carbonyl removal
efficiencies versus the control cigarette (7-CTL).
TABLE-US-00014 TABLE 14 Micrograms aldehyde/cigarette (% reduction
versus 7-CTL) * Cigarette # Material # Weight ** Formaldehyde
Acetaldehyde Acrolein Propionaldehyde Crotonaldehyde 7-CTL * -- --
21.8 724.2 68.3 60.4 26.3 7-C1 G278 25 21.6 (0.8) 526.7 (27.3) 37.3
(45.4) 35.7 (40.9) 16.5 (37.2) 7-C2 G278 50 19.1 (12.4) 332.2
(54.1) 19.6 (71.4) 19.2 (68.2) 10.1 (61.4) 7-C3 G278 75 18.6 (14.8)
201.9 (72.1) 11.3 (83.5) 11.3 (81.3) 5.8 (77.9) 7-1C 7-1 100 16.6
(23.7) 316.5 (56.3) 7.2 (89.5) 14.6 (75.8) 12.5 (52.3) 7-2C 7-2 100
16.8 (22.7) 267.3 (63.1) 6.1 (91.1) 13.2 (78.2) 12.1 (53.8) 7-3C *
7-3 100 18.1 (17.1) 305.7 (57.8) 16.1 (76.4) 16.5 (72.7) 7.2 (72.5)
7-4C * 7-3 125 16.9 (22.6) 232.5 (67.9) 12.2 (82.2) 12.9 (78.7) 6.5
(75.4) G278 = G278 (18 .times. 40 mesh) activated coconut carbon
supplied by PICA USA (Columbus, OH) * Aldehyde contents are the
average of triplicate tests; -- = not applicable; ** = milligrams
of material per cigarette.
Example 8
[0094] This is an example of how to prepare activated carbon for
practice of the invention. In this example, 8.3 pounds of fructose
(Krystar 300, Tate & Lyle, A. E. Staley Manufacturing Company;
Decatur, Ill.) and 8.3 pounds mannitol (Mannitol, USP, Welco) are
dissolved in 18.5 pounds of water. Using a mixer, the aqueous
solution is sprayed on 150 pounds of G278 activated coconut carbon
(18.times.40 mesh, supplied by PICA USA; Columbus, Ohio). After
treatment, the carbon tetrachloride activity of the treated carbon
was found to be 38.3 (Carbon tetrachloride number=2.55.times.butane
activity as determined by ASTM method D5742-95 "Standard Test
Method for Determination of Butane Activity of Activated
Carbon").
Example 9
[0095] Approximately 37.5 pounds of A109 resin (18.times.40 mesh
wet, Purolite USA, Bala Cynwyd, Pa.) was separated into five
batches of approximately 7.5 pounds. Each batch was washed four
times with approximately 3 gallons of water. The moist batches were
combined and dried in a convection oven at 60.degree. C. for 24
hours. The moisture content of the solid was found to be 34.94% by
Karl Fischer titration.
[0096] Activated carbon treated with a 46:46:8 mixture by weight of
fructose, mannitol and sodium chloride was prepared at PICA USA by
treating 1,000 pounds of G278 activated carbon with an aqueous
solution containing 54.5 pounds of fructose, 54.5 pounds of
mannitol, 10 pounds of sodium chloride, and 142.5 pounds of water.
After treatment, the carbon tetrachloride activity of the carbon
was found to be 35.1 (Carbon tetrachloride number=2.55.times.butane
activity as determined by ASTM method D5742-95 "Standard Test
Method for Determination of Butane Activity of Activated Carbon").
The treated carbon mixture contained 11% by total weight of the
46:46:8 fructose/mannitol/sodium chloride mixture.
[0097] 84 millimeter cigarettes having non-ventilated filters like
that of FIG. 1 were prepared. Cigarettes were produced having
approximately 100 mg of gas-phase filtering material constituting
the various mixtures of treated carbon and resin as shown in Table
15. In addition, two control cigarettes were prepared, one in which
the cavity was filled with 125 g. of treated carbon assigned a
value of "10" for overall acceptability and off-taste and another
having an empty filter cavity which represented "0" for off-taste.
Results of the taste evaluation are given in Table 15.
TABLE-US-00015 TABLE 15 Sample # Carbon.sup.1 (mg) Resin (mg)
Carbon:Resin.sup.2 OA.sup.3 OT.sup.4 A 0.0 100.0 0:100 8.0 5.0 B
25.0 75.0 25:75 13.3 4.5 C 50.0 50.0 50:50 11.1 6.9 D 75.0 25.0
75:25 9.1 8.8 E 87.5 12.5 82:14 7.5 10.5 .sup.1Treated carbon;
.sup.2Weight:weight ratio of treated carbon to resin; .sup.3OA =
Overall Acceptability; .sup.4OT = Off-taste compared to control
having 125 mg of treated carbon.
[0098] During this study it was observed that the A109 resin
imparts off-taste to cigarettes. This off-taste is likely due, in
part, to trace amounts of the manufacturing chemicals such as
primary amines in the resin. Washing the resin as described above,
prior to use was found to considerably reduce the off-taste
associated with the resin. Even after washing, cigarettes
containing 100% A109 resin still had some off-taste similar to
carbon off-taste as shown in Table 15. It is theorized that this
off-taste results from the macroporous structure of the resin the
profile of organic constituents in the mainstream smoke similar to
way activated carbon is theorized to produce off-taste.
[0099] The highest overall acceptability was obtained from
cigarettes B and C, having 25 weight % and 50 weight % treated
carbon, respectively. Cigarettes B and C had a higher overall
acceptability than either cigarette A having 100% resin or the 100%
treated carbon control cigarette. Observed off-taste was lowest in
cigarette B. Cigarette B also gave substantial reduction in
off-taste. It is theorized that the presence of about 25-50 weight
% carbon in these cigarettes, in addition to reducing gas-phase
constituents from the tobacco, reduces the amounts of trace
manufacturing chemicals introduced into the smoke from the resin.
These example demonstrates a synergy in the use of carbon/resin
mixtures.
[0100] Table 16 shows the gas-phase removal data for each of the
cigarettes in Table 19, calculated as % reduction compared to the
control cigarette having an empty filter cavity.
TABLE-US-00016 TABLE 16 Sample Formaldehyde.sup.1 Acetaldehyde
Acrolein Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 A 40.1
84.4 88.6 78.2 68.9 675 B 19.4 72.5 75.5 71.8 77.3 965 C 17.1 69.3
78.2 70.6 78.9 769 D 10.3 54.3 72.8 65.7 72.6 494 E 19.2 56.1 79.5
70.6 79.3 421 .sup.1All data represents % reduction in comparison
to the control cigarette with an empty cavity; .sup.2OA .times. Ac
= Overall Acceptability .times. % reduction in acetaldehyde.
[0101] A can be seen from Table 16, cigarette A having 100% resin
gives the highest carbonyl removal efficiency. However, as the
usefulness of a particular gas-phase filter material treatment
depends on the ability to suppress off-taste as well as the ability
to reduce gas-phase constituents. The product of the overall
acceptability and gas phase removal ability of each cigarette
provides one means for evaluating the optimal mixtures of treated
carbon and resin. By this measure, cigarettes B and C, having 25
weight % and 50 weight % treated carbon, respectively, are the most
useful according to the invention.
Example 10
[0102] Activated coconut carbon was treated with various materials
as listed in Table 17. For all samples listed in this example, G278
(18.times.40 mesh) activated coconut carbon supplied by PICA USA
(Columbus, Ohio) was used.
[0103] The carbon material was treated according to the following
general procedure. Treatment material was dissolved in water. Then
the resulting solution was applied to untreated carbon. Sufficient
treatment material was added to the water to yield the final
application as listed in Table 17. Generally, water to carbon
ratios of approximately 1.8:1 were used. The wet carbon was then
dried at approximately 60.degree. C. for approximately 8 hours.
TABLE-US-00017 TABLE 17 Material Application (grams # Treatment *
treatment/grams carbon) 9-1 Fructose, Mannitol, Glycine 0.1025,
0.1020, 0.0167 Sodium Salt Hydrate 9-2 Fructose, Mannitol,
Monosodium 0.1018, 0.1013, 0.0321 Glutamate Monohydrate 9-3
Fructose, Mannitol, Sodium 0.1020, 0.1015, 0.0370 Gluconate 9-4
Fructose, Mannitol, Sodium 0.1023, 0.1018, 0.0101 Chloride *
Fructose, Cat #14,092-9, Aldrich Chemical Company (Milwaukee, WI);
Mannitol, Cat #25,409-6, Aldrich Chemical Company (Milwaukee, WI);
Glycine Sodium Salt Hydrate, Cat #21,951-7, Aldrich Chemical
Company (Milwaukee, WI); Monosodium Glutamate Monohydrate, Cat
#G283-4, Aldrich Chemical Company (Milwaukee, WI); Sodium
Gluconate, Cat #18,633-3, Aldrich Chemical Company (Milwaukee, WI);
Sodium Chloride, Non-iodized, Morton International, Morton Salt
(Chicago, IL).
[0104] 99-millimeter cigarettes having ventilated filters like that
of FIG. 1 were prepared. After drying, approximately 150 milligrams
of treated carbon were loaded into the 6 millimeter cavities. These
cigarette were tested against a control cigarette (9-CTL, Table 17)
having a single cellulose acetate plug with no carbon.
[0105] Cigarettes were analyzed for whole smoke carbonyl content.
Whole smoke carbonyl content and carbonyl reduction data is given
in Table 18.
TABLE-US-00018 TABLE 18 Micrograms aldehyde/cigarette (% reduction
versus 9-CTL) * Cig. # Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde 9-CTL 24.2 717.0 70.6 64.0 31.5 9-1C
21.6 (10.9) 306.1 (57.3) 11.6 (83.6) 18.7 (70.7) 9.8 (68.8) 9-2C
17.2 (29.1) 317.4 (55.7) 16.2 (77.0) 22.3 (65.1) 9.5 (69.8) 9-3C
25.4 (-4.9) 506.3 (29.4) 25.3 (64.2) 34.8 (45.6) 14.0 (55.6) 9-4C
19.1 (21.0) 328.1 (54.2) 12.7 (82.0) 21.3 (66.7) 9.8 (68.8) *
Aldehyde contents are the average of duplicate tests.
[0106] Cigarette types as listed in Table 17 were smoked and
evaluated for taste properties. Unexpectedly, applicants discovered
that treating the carbon with combined sodium salt and sugar/polyol
mixtures gave greater carbon off-taste suppression than
sugar/polyol mixtures alone. Table 17 lists the off-taste
suppressant in order of effective off-taste suppression. Thus,
material 9-4C gave greater off-taste suppression than material 9-2C
which, in turn, gave greater off-taste suppression than material
9-1C. In this test, the off-taste suppression from material 9-3C
was approximately equal to that from material 9-4C. Overall,
cigarette samples 9-1C, 9-2C, 9-3C, and 9-4C all exhibited
significant suppression of carbon off-taste.
Examples 11-16
[0107] It has been determined that use of certain amounts of
off-taste suppressant provide unexpectedly better reduction in
carbon off-taste while maintaining acceptable gas-phase removal
properties as demonstrated by the following examples. Unless
otherwise indicated, in the following Examples the treated carbons
were prepared by dissolving the indicated amount of off-taste
suppressant in 20 ml of water followed by application to 10 mg of
activated carbon. Following evaporation of water, the treated
carbon was dried at 60.degree. C. for 10 hours.
[0108] 85 mm hand made cigarettes having plug-space-plug filters
like that of FIG. 1 were prepared. The filters had a 10 mm plug of
fiber tow at the buccal end, a 9 mm plug of fiber tow at the
upstream end and a 6 mm cavity in between. In each instance, 150 mg
of activated carbon treated with off-taste suppressant were loading
into the cavity.
[0109] The cigarettes were smoked by a panel consisting of three
professional expert smokers and evaluated for carbon off-taste
reduction and overall acceptability. Carbon off-taste for each
cigarette was evaluated on a 0 to 10 scale, with a control
cigarette (G278) having 150 mg of untreated activated carbon
representing "10" on the scale and another control cigarette having
an empty cavity representing "0" on the scale. The smoking panel
also ranked each cigarette for overall acceptability on a 1 to 10
scale with G278 representing "1" and the cigarette with the empty
cavity representing "10". Each cigarette was evaluated based on the
third, fourth, and fifth puff.
[0110] For each cigarette in the Examples, gas-phase removal data
was determined by using a method similar to that used by Arista
Laboratories (Richmond, Va.). Cigarettes were smoked by a smoking
machine and the mainstream smoke was trapped in an aqueous solution
of dinitrophenyl hydrazine (DNPH). The resulting DNPH aldehyde
derivatives were analyzed by HPLC to determine the quantity of
selected aldehydes. The gas-phase reduction data in the Examples is
expressed in terms of percent reduction in selected gas phase
components in relation to the control cigarette having an empty
cavity. In each instance the data represents the average of two
measurements.
Example 11
[0111] To determine the effect of fructose loading on carbon
off-taste suppression, overall acceptability, and carbonyl
reduction, cigarettes were prepared with varying amounts of
fructose present on activated carbon. As shown in Table 19,
cigarettes were prepared with carbon materials having fructose
loadings varying from about 2 weight % to about 40 weight %.
TABLE-US-00019 TABLE 19 Sample Wt % Fructose Fructose (g).sup.1
OA.sup.2 Carbon OT.sup.3 F-2 2 0.20 1.7 9.5 F-5 5 0.53 2.1 8.8 F-7
7 0.75 2.5 8.5 F-10 10 1.11 3.7 7.3 F-15 15 1.77 4.3 6.7 F-20 20
2.50 5.8 4.7 F-25 25 3.33 5.5 3.8 F-30 30 4.29 4.0 3.0 F-35 35 5.39
4.0 2.7 F-40 40 6.67 3.0 3.2 .sup.1Grams of fructose dissolved in
20 ml of water for each 10 g of activated carbon .sup.2Overall
acceptability (OA) .sup.3Carbon off-taste (Carbon OT)
[0112] For each sample, the overall acceptability was rated as
greater than that for untreated carbon, which was assigned a "1."
It is apparent from FIG. 4, which graphs the off-taste reduction
data in Table 19, carbon off-taste decreased as the loading of
fructose was increased, with a gradual leveling off of off-taste
suppression beginning at loadings above about 20 weight %. Notably,
as illustrated in FIG. 4, which also graphs the overall
acceptability data in Table 19, the overall acceptability of these
cigarettes increased with fructose loading up to about 20 weight %
and then began to diminish at loadings above about 20 weight %.
There was generally an inverse relationship between the carbon
off-taste reduction and the overall acceptability as the loading of
the off-taste suppressant was increased.
[0113] Table 20 shows the gas-phase removal data for each of the
cigarettes in Table 19, calculated as % reduction as compared the
control cigarette having an empty cavity.
TABLE-US-00020 TABLE 20 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 F-2 40.7.sup.1
91.7 96.7 93.5 95.8 153 F-5 34.2 83.9 91.9 89.0 91.1 182 F-7 41.6
82.7 91.9 88.8 89.4 207 F-10 27.2 72.4 88.6 82.5 81.2 266 F-15 33.9
72.0 89.9 84.0 83.5 312 F-20 31.3 54.6 86.0 71.7 72.9 319 F-25 26.0
26.9 74.2 41.3 43.2 148 F-30 19.0 7.9 57.0 13.0 2.9 31 F-35 24.8
15.8 61.7 16.1 -1.0 63 F-40 17.8 7.9 56.2 8.2 -17.0 24 .sup.1All
data represents % reduction in comparison to the control cigarette.
.sup.2OA .times. Ac = Overall Acceptability .times. % reduction in
acetaldehyde.
[0114] As shown in Table 20, the ability of the treated carbon to
remove gas-phase constituents diminishes rapidly at fructose
loadings above about 15 weight %. This effect is likely due to
deactivation of the carbon caused by increased blocking of its
active sites. This conclusion is supported by the fact the treated
activated carbon began caking at fructose loadings of about 15
weight %, suggesting that the surface of the activated carbon is
highly coated with fructose.
[0115] Table 20 provides values for the product of overall
acceptability and % acetaldehyde reduction for each cigarette. By
this measure, a useful range of fructose loading is between about 2
and about 25% by weight.
Example 12
[0116] To determine the effect of mannitol loading on carbon
off-taste suppression, overall acceptability, and carbonyl
reduction, the cigarettes shown in Table 21 were prepared with
amounts of mannitol from about 2 weight % to about 40 weight %.
TABLE-US-00021 TABLE 21 Sample Wt % Mannitol Mannitol (g).sup.1
OA.sup.2 Carbon OT.sup.3 M-2 2 0.20 1.7 9.0 M-5 5 0.53 2.5 8.3 M-7
7 0.75 3.5 7.7 M-10 10 1.11 4.7 6.3 M-15 15 1.77 5.3 5.2 M-20 20
2.50 6.0 4.2 M-25 25 3.33 5.7 4.2 M-30 30 4.29 5.0 3.8 M-35 35 5.39
4.5 3.5 M-40 40 6.67 3.3 3.5 .sup.1Grams of mannitol dissolved in
20 ml of water for each 10 g of activated carbon .sup.2Overall
acceptability (OA) .sup.3Carbon off-taste (Carbon OT)
[0117] In each case there was a greater overall acceptability for
the treated carbon than was observed for cigarettes having
untreated carbon. As was the case with fructose, it is apparent
from FIG. 5, which graphs the off-taste reduction data in Table 21,
that carbon off-taste decreased as the loading of fructose was
increased, with a leveling off of off-taste suppression beginning
at about 20 weight %. As illustrated in FIG. 5, which also graphs
the overall acceptability data in Table 21, the overall
acceptability increased with mannitol loading up to about 20 weight
% and then begins to diminish at loadings above about 20 weight
%.
[0118] Table 22 shows the gas-phase removal data for each of the
cigarettes in Table 21, calculated as % reduction as compared to
the control cigarette having an empty cavity.
TABLE-US-00022 TABLE 22 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 M-2 48.4.sup.1
90.6 95.3 94.2 94.0 151 M-5 45.1 82.8 93.8 89.1 87.7 207 M-7 42.5
80.7 95.1 88.9 87.0 282 M-10 40.1 75.1 95.1 85.1 81.9 350 M-15 42.7
67.3 93.8 78.3 74.2 359 M-20 50.5 62.6 94.4 76.0 73.1 376 M-25 40.2
33.4 87.6 53.2 48.3 189 M-30 37.2 28.4 83.1 44.4 39.5 142 M-35 4.8
10.4 -11.6 22.4 58.7 47 M-40 13.8 11.0 17.8 30.5 62.4 37 .sup.1All
data represents % reduction in comparison to the control cigarette
having an empty cavity. .sup.2OA .times. Ac = Overall Acceptability
.times. % reduction in acetaldehyde.
[0119] As shown in Table 22, the ability of the treated carbon to
remove gas-phase constituents diminished rapidly at mannitol
loadings above about 20 weight %. Since mannitol became visible as
a white coating on the activated carbon particles at about 15
weight %, it is believed that the activated carbon gradually became
deactivated at the highest loadings of mannitol.
[0120] Table 22 provides values for the product of overall
acceptability and % acetaldehyde reduction for each cigarette. By
this measure, a useful range of mannitol loading is between 5 and
20 weight %.
Example 13
[0121] Off-taste suppressants consisting of 50/50 weight % mixtures
of mannitol and fructose were examined to determine the effect of
loading on carbon off-taste suppression, overall acceptability, and
carbonyl reduction. As shown in Table 23, treated carbon materials
were prepared with 50/50 weight % mixtures of mannitol and fructose
at loadings varying from about 2 weight % to about 40 weight % of
the admixture.
TABLE-US-00023 TABLE 23 50:50 M:F Mannitol Fructose Carbon Sample
Wt %.sup.1 (g).sup.2 (g).sup.3 OA.sup.4 OT.sup.5 MF-2 2 0.10 0.10
1.8 8.8 MF-5 5 0.26 0.26 2.7 8.2 MF-7 7 0.37 0.37 3.7 7.3 MF-10 10
0.55 0.55 5.0 6.0 MF-15 15 0.88 0.88 5.7 5.2 MF-20 20 1.25 1.25 6.5
3.7 MF-25 25 1.67 1.67 5.5 4.5 MF-30 30 2.14 2.14 5.2 4.3 MF-35 35
2.69 2.69 4.3 3.5 MF-40 40 3.33 3.33 3.5 3.8 .sup.1Weight % of a
50:50 (wt. %) admixture of mannitol and fructose. .sup.2Grams of
mannitol dissolved in 20 ml of water for each 10 g of activated
carbon. .sup.3Grams of fructose dissolved in 20 ml of water for
each 10 g of activated carbon. .sup.4Overall acceptability (OA)
.sup.5Carbon off-taste (Carbon OT)
[0122] As can be seen from Table 23, substantial off-taste
suppression was observed for every loading of the 50/50 weight %
admixture of mannitol and fructose. Additionally, the overall
acceptability for each cigarette having treated carbon was greater
than for the cigarette having untreated carbon. As is evident from
FIG. 6, which graphs the off-taste reduction data in Table 23,
there was a greater reduction in carbon off-taste as the loading of
fructose was increased, with a gradual leveling of off-taste
suppression at loadings above 15 weight %. As also illustrated in
FIG. 6, the overall acceptability increased with loading up to 20
weight % and then began to diminish at loadings above 20 weight
%.
[0123] Surprisingly, a synergistic effect was observed with the
50/50 weight % admixture of mannitol and fructose as compared to
either mannitol or fructose alone. At loading from 2 weight % up to
20 weight % the admixture of mannitol and fructose yielded greater
overall acceptability and greater carbon off-taste suppression than
mannitol or fructose alone.
[0124] Table 24 shows the gas-phase removal data for each of the
cigarettes in Table 23, calculated as % reduction as compared to
the control cigarette having an empty cavity.
TABLE-US-00024 TABLE 24 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 MF-2 38.8.sup.1
85.6 93.2 91.6 94.0 157 MF-5 35.3 78.5 91.0 86.9 88.5 209 MF-7 33.2
84.8 91.2 92.6 94.0 311 MF-10 31.0 76.5 87.9 87.6 90.6 383 MF-15
18.1 56.4 70.4 72.4 81.0 319 MF-20 16.6 40.3 62.0 59.9 74.2 262
MF-25 4.2 17.8 12.6 34.8 78.2 98 MF-30 -6.5 -3.0 -41.3 3.4 55.8 -15
MF-35 -3.3 -3.9 -41.8 -3.1 35.8 -17 MF-40 -23.9 -14.9 -62.5 -14.6
18.1 -52 .sup.1All data represents % reduction in comparison to the
control cigarette with an empty cavity. .sup.2OA .times. Ac =
Overall Acceptability .times. % reduction in acetaldehyde.
[0125] As shown in Table 24, the ability of the treated carbon to
remove gas-phase constituents diminishes rapidly at loadings above
15 weight %.
[0126] Table 24 provides values for the product of overall
acceptability and % acetaldehyde reduction for each cigarette. By
this measure, a useful loading range for a 50:50 wt. % admixture of
mannitol and fructose is between 5 and 20 weight %.
Example 14
[0127] To further investigate the synergistic effect of off-taste
suppressants consisting of mannitol and fructose mixtures,
cigarette were prepared having varying weight % ratios of mannitol
to fructose. As shown in Table 24, activated carbon materials were
prepared at 20 weight % loadings of admixtures varying from 10:90
to 90:10 (weight %) ratios of mannitol to fructose.
TABLE-US-00025 TABLE 25 Wt. Ratio Mannitol Fructose Carbon Sample
M:F.sup.1 (g).sup.2 (g).sup.3 OA.sup.4 OT.sup.5 MF 10-90 10:90 0.25
2.25 5.3 5.0 MF 25-75 25:75 0.66 1.88 6.0 4.8 MF 50-50 50:50 1.25
1.25 7.3 3.8 MF 75-25 75:25 1.88 0.63 6.2 4.7 MF 90-10 90:10 2.25
0.25 5.3 4.7 .sup.1Ratio of mannitol to fructose (wt./wt.); Total
carbon loading of 20 wt. %. .sup.2Grams of mannitol dissolved in 20
ml of water for each 10 g of activated carbon. .sup.3Grams of
fructose dissolved in 20 ml of water for each 10 g of activated
carbon .sup.4Overall acceptability (OA) .sup.5Carbon off-taste
(Carbon OT)
[0128] As can be seen from Table 25, substantial off-taste
suppression was observed for every ratio of mannitol to fructose.
Additionally, the overall acceptability for each cigarette having
treated carbon was greater than for the cigarette having untreated
carbon. It was observed that the greatest reduction in carbon
off-taste and the largest overall acceptability occurs with about a
50:50 weight/weight ratio of mannitol to fructose.
[0129] Table 26 shows the gas-phase removal data for each of the
cigarettes in Table 25, calculated as % reduction as compared to a
control cigarette having an empty cavity.
TABLE-US-00026 TABLE 26 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 MF 10-90
35.8.sup.1 61.8 79.6 80.8 85.6 330 MF 25-75 23.5 49.0 68.9 70.1
75.3 294 MF 50-50 23.0 52.5 69.7 73.1 87.4 385 MF 75-25 15.7 50.8
65.0 69.3 82.1 314 MF 90-10 24.0 53.8 65.5 71.1 86.8 287 .sup.1All
data represents % reduction in comparison to the control cigarette.
.sup.2OA .times. Ac = Overall Acceptability .times. % reduction in
acetaldehyde.
[0130] Table 26 provides values for the product of overall
acceptability and % acetaldehyde reduction for each cigarette.
While each of these cigarettes exhibit excellent overall
acceptability and gas-phase removal properties, the cigarette
having about a 50:50 weight/weight ratio of mannitol and fructose
is the most useful according to the present invention.
Example 15
[0131] The effect of sodium chloride on carbon off-taste
suppression, overall acceptability, and carbonyl reduction was
studied. Off-taste suppressants consisting of 46:46:8 weight %
mixtures of mannitol, fructose, and sodium chloride were examined
at varying total loadings on activated carbon. As shown in Table
27, treated carbon materials were prepared with this mixture of
mannitol, fructose, and sodium chloride at loadings varying from
about 2 weight % to about 40 weight % of the admixture.
TABLE-US-00027 TABLE 27 M:F:N Mannitol Fructose NaCl Carbon Sample
Wt %.sup.1 (g).sup.2 (g).sup.3 (g).sup.4 OA.sup.5 OT.sup.6 MFN-2 2
0.09 0.09 0.02 2.3 8.7 MFN-5 5 0.24 0.24 0.04 2.8 7.8 MFN-7 7 0.35
0.35 0.06 3.7 7.2 MFN-10 10 0.54 0.54 0.10 5.3 5.7 MFN-15 15 0.81
0.81 0.15 6.7 4.3 MFN-20 20 1.15 1.15 0.21 7.7 3.8 MFN-25 25 1.53
1.53 0.28 7.5 3.0 MFN-30 30 1.96 1.96 0.36 6.2 3.5 MFN-35 35 2.47
2.47 0.45 4.8 3.7 MFN-40 40 3.05 3.05 0.56 3.0 3.5 .sup.1Weight %
of a 46:46:8 (wt. %) admixture of mannitol, fructose, and sodium
chloride. .sup.2Grams of mannitol dissolved in 20 ml of water for
each 10 g of activated carbon. .sup.3Grams of fructose dissolved in
20 ml of water for each 10 g of activated carbon .sup.4Grams of
sodium chloride dissolved in 20 ml of water for each 10 g of
activated carbon. .sup.5Overall acceptability (OA) .sup.6Carbon
off-taste (Carbon OT)
[0132] As can be seen from Table 27, substantial off-taste
suppression was observed for every loading of the 46:46:8 (weight
%) admixture of mannitol, fructose, and sodium chloride.
Additionally, the overall acceptability for each cigarette having
treated carbon was greater than for the cigarette having untreated
carbon. Greater reduction in carbon off-taste was observed with a
46:46:8 (weight %) admixture of mannitol, fructose, and sodium
chloride than was observed for the 50:50 (weight %) admixture of
mannitol and fructose for loadings from 2 weight % to 15 weight. %.
Furthermore, the overall acceptability was generally much greater
for the 46:46:8 (weight %) admixtures of mannitol, fructose, and
sodium chloride than was observed for the 50:50 (weight %)
admixtures of mannitol and fructose.
[0133] As is evident from FIG. 7, which graphs the off-taste
reduction data in Table 27, reduction in carbon off-taste increased
as the loading of off-taste suppressant was increased, with a
gradual leveling off of off-taste suppression at loadings above
about 15 weight %. As also illustrated in FIG. 7, the overall
acceptability increased with loading up to about 20 weight % and
then began to diminish at loadings above about 20 weight %.
[0134] Table 28 shows the gas-phase removal data for each of the
cigarettes in Table 27, calculated as % reduction as compared to
the control cigarette having an empty cavity.
TABLE-US-00028 TABLE 28 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.2 MFN-2 32.6.sup.1
90.2 93.6 95.6 96.4 210 MFN-5 21.4 81.5 87.4 90.4 92.3 231 MFN-7
39.2 84.5 91.7 92.4 92.6 310 MFN-11 28.7 76.1 82.4 87.4 95.0 406
MFN-15 19.8 64.9 74.3 80.0 91.2 433 MFN-20 25.8 51.7 66.6 70.2 85.7
396 MFN-25 10.3 25.4 37.4 42.5 72.6 191 MFN-30 -2.9 1.7 -56.6 6.6
75.2 10 MFN-35 -0.6 -2.2 -68.6 -0.8 60.7 -11 MFN-40 -2.6 1.8 -58.6
0.7 49.5 5.5 .sup.1All data represents % reduction in comparison to
the control cigarette. .sup.2OA .times. Ac = Overall Acceptability
.times. % reduction in acetaldehyde.
[0135] Table 28 provides values for the product of overall
acceptability and % acetaldehyde reduction for each cigarette. By
this measure, a useful loading range for a 46:46:8 weight %
admixture of mannitol, fructose, and sodium chloride is between
about 2 and 25 weight %. This treatment is most effective at
loadings between about 7 and 20 weight. %. As indicated by this
data, the 46:46:8 weight % admixture of mannitol, fructose, and
sodium chloride is superior to the other off-taste suppressants
described herein.
Example 16
[0136] For this example, G278 (18.times.40 mesh) activated coconut
carbon supplied by PICA USA (Columbus, Ohio) was treated with
mannitol, fructose, and sodium chloride in a large-scale spray
process. Fructose (Krystar 300, Tate & Lyle, A. E. Staley
Manufacturing Company; Decatur, Ill.)54.5 lbs, mannitol (Mannitol,
USP, Welco) 54.5 lbs, and sodium chloride (Evaporated Granulated
Salt, Morton Salt Company; Chicago, Ill.), 10 lbs, were dissolved
in 142.5 lbs water. A baffle mixer was used to coat 1000 lbs G278
coconut carbon (PICA USA; Columbus, Ohio). There was no drying step
of the treated carbon subsequent to spray treatment. The total
loading of off-taste suppressant on the activated carbon was
approximately 11 weight percent.
[0137] 84 mm cigarettes having filters like that of FIG. 1 were
prepared. 150 milligrams of the spray-treated carbon were loaded
into the 6 mm cavities to yield sample cigarette GX-061. To
determine the effect of spray treatment on off-taste suppression,
overall acceptability, and gas-phase carbonyl removal, GX-061 was
compared to MFN-11. The activated carbon of cigarette MFN-11 had
been treated by the laboratory method described previously, rather
than a spray method, using the identical off-taste suppressant and
loading as GX-061.
[0138] The results of the smoking panel analysis are shown in Table
29.
TABLE-US-00029 TABLE 29 Sample M:F:N (wt. %) OA.sup.1 Carbon
OT.sup.2 MFN 11 46:46:8 5.3 5.7 GX-061 46:46:8 6.8 4.0
.sup.1Overall acceptability (OA) .sup.2Carbon off-taste (Carbon
OT)
[0139] As can be seen from Table 29, greater off-taste suppression
was observed for the spray-treated sample than for the laboratory
treated sample. Additionally, the overall acceptability for the
sample with spray-treated carbon was greater than for the sample
with solution-treated carbon, despite the fact that both samples
had the same mannitol-fructose-sodium chloride loadings. It is
theorized that the off-taste suppressant tends to remain on the
outer surface of the carbon granules when spray treated and thus
has a slightly higher availability for suppressing off-taste as
compared to the laboratory prepared sampled in which the off-taste
suppressant has likely penetrated the pores of the activated carbon
to some extent.
[0140] Table 30 shows the gas-phase removal data as % reduction
when compared to the control cigarette with an empty cavity.
TABLE-US-00030 TABLE 30 Sample Formaldehyde Acetaldehyde Acrolein
Propionaldehyde Crotonaldehyde OA .times. Ac.sup.1 MFN 11 28.7 76.1
82.4 87.4 95.0 405.92 GX-061 30.6 66.6 82.4 78.9 82.3 455.32
.sup.1OA .times. Ac = Overall Acceptability .times. % reduction in
acetaldehyde.
[0141] As can be seen in Table 30, there is some variability in the
carbonyl removal data between the lab treated sample MFN 11 and the
spray treated sample GX-061. While the cigarette with laboratory
treated carbon shows a slightly higher acetaldehyde reduction, the
cigarette with spray-treated carbon tests higher when the
acetaldehyde reduction and overall acceptability are factored
together. By this measure, cigarette GX-061 is the most useful
cigarette according to the invention of all those tested
herein.
[0142] While it is contemplated that in the practice of the present
invention, one will be able to produce carbon filtered cigarettes
which taste substantially like non-carbon filtered cigarettes, it
should be understood that off-taste suppressants which also
introduce flavor into the mainstream smoke are contemplated to be
within the broad scope of the invention. However, "masking" carbon
off-taste by flavoring the mainstream smoke is not the effective
mechanism of carbon off-taste reduction according to the present
invention, as demonstrated by the foregoing Examples. For instance,
Example 12 demonstrates that there is a 37% reduction in carbon
off-taste compared to an untreated carbon cigarette at a mannitol
loading of 10 weight %. In view of the fact that smokers with
highly acute taste perceptions did not detect even trace levels of
mannitol in the mainstream smoke at that 10% loading and up until
the mannitol loading reached 15 weight %, it is apparent that
flavoring of the mainstream smoke was not the reason for off-taste
suppression. Furthermore, in Examples 11-13 and 15, reduction in
the carbon off-taste gradually levels off at off-taste suppressant
loadings above about 20-25 weight % as illustrated in FIGS.
4-7.
[0143] While the amount of off-taste suppressant used in the
practice of the invention may be such that certain smokers perceive
an additional sweet flavor, it is clear that the off-taste
suppressants of the invention function by a mechanism that is
independent of the amount of sweetness added to the mainstream
smoke. One can control the presence and the amount of sweetness in
the mainstream smoke by selecting appropriate compositions and
loadings off-taste suppressant consistent to the preferences of the
targeted consumer. In this regard, it will be understood that the
threshold of detectability of the off-taste suppressants in the
mainstream smoke may be higher for some smokers. In the preferred
practice of this invention, the off-taste suppressants do not
impart detectable flavor to the mainstream smoke.
[0144] Certain modifications and improvements will occur to those
skilled in the art upon a reading of the foregoing description. It
should be understood that all such modifications and improvements
have been deleted herein for the sake of conciseness and
readability but are properly within the scope of the following
claims.
* * * * *