Note: Descriptions are shown in the official language in which they were submitted.
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15
TOBACCO FILLER OF LOW NITROGEN CONTENT
FIELD OF INVENTION
This invention relates generally to tobacco and reconstituted tobacco smoking
materials and methods of making same. More particularly, the present invention
relates
to the materials and methods that provide smoking materials with low nitrogen
content.
BACKGROUND
Tobacco material contains various nitrogenous compounds that can adversely
affect its
smoke quality. Among these nitrogenous compounds are proteins, amino acids,
heterocyclic aromatic amines, tobacco specific nitrosamines (TSNA), as well as
other
compounds formed by pyrolysis or transfer of these nitrogenous compounds. It
has been
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determined that tobacco quality is improved by reducing its nitrogen content.
It has been
found to be relatively easy to remove protein from uncured tobacco leaf,
however there are
disadvantages to removing protein before curing. The protein broken down
during curing
form flavor compounds that are important contributors to the organoleptic
properties of the
smoke. Another disadvantage is that efficient extraction of green leaf usually
necessitates
tobacco structural changes which make it difficult to produce shredded tobacco
suitable for
use as a cigarette filler. Tobacco processing sometimes includes steps in
which the nitrogen
content of the tobacco is reduced, so as to improve the smokability of the
tobacco. However,
nitrogenous compounds, especially proteins, are difficult to extract from
cured tobacco
lamina, stem, and fiber cell walls.
Plant proteins are divided into four major classes: albumins; globulins;
prolamins
(also known as gliadins); and, glutelins. Albumins are soluble in water,
whereas globulins
are soluble in dilute salt solutions. Prolamins are soluble in dilute acid or
alkali solutions,
while glutelins are soluble in alcohol solutions. Some proteins, however,
overlap into two of
these four classifications, thereby increasing the difficulty of accurately
predicting the
appropriate diluent. Insoluble proteins make up 85% to 95% of the total
proteins found in
cured tobacco. These insoluble proteins are globular in conformation, and are
bound to
lipoidal organocellular membranes of fiber or cellulose cell walls.
Solubilization and
extraction of these insoluble proteins have proven difficult when using water
or solvents
under moderate digestion conditions (i.e. less than 100 C at 65-70 psig) and
with shredded
tobacco of size suitable for cigarette manufacture. Partial removal of protein
from cured
tobacco can be accomplished by extraction with water, with the efficiency of
the extraction
improving as the particle size is reduced. However, for shredded tobacco of
the size
normally used for cigarette manufacture, most of the protein cannot be
extracted by water
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alone. This difficulty is due in large part to the compact and rigid structure
of fiber cells.
Penetration of rigid cell wall structure by solvents has proven feasible only
after thermal
and/or mechanical sample treatment. However, the common result of such sample
treatment
is poor recovery of the solvated particulate material. Moreover, cell wall
penetration does not
necessarily lead to protein solubilization, since plant proteins differ in
their conformity and
solubilization patterns.
Many of the current processes used to reduce nitrogen content in tobacco
material
employ enzymatic compounds and microbial agents to break down the proteins and
other
nitrogen-containing compounds within the tobacco. Several inventors have found
that
proteolytic enzymes will break down tobacco protein into readily soluble
fragments and that
strip or cut tobacco can be treated by such enzymes. Gaisch et al. (U.S. Pat.
No.
4,407,307) described the removal of protein from tobacco strips in an aqueous
solution of a
proteolytic enzyme whereby insoluble proteins are decomposed into soluble
fragments. The
extract is separated from the tobacco and inoculated with a yeast culture,
which, as it grows,
removes the soluble protein fragments in the extract by metabolic
assimilation. After
removal of the yeast, the protein-free extract is concentrated and added back
to the tobacco
strips. Bernasek et al. (U.S. Pat. No. 4,887,618) describes a process in which
tobacco is
first extracted with water. The tobacco residue remaining after extraction is
separated from
the solution, mixed with water and treated with a proteolytic enzyme. The
protein-reduced
tobacco is separated from the enzyme solution, rinsed and dried. The water
extract is
concentrated and added back to the protein reduced tobacco. The advantage
described by
Bernasek et al. for this process is that the water soluble flavor components
of tobacco and the
nicotine can be retained in the final product.
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DeGrandpre et al. (U.S. Pat. No. 5,311,886) teaches a process where cut
tobacco is
extracted in an aqueous solution having a surfactant and proteolytic enzyme.
The proteolytic
enzyme, if used, is chosen from the group comprising the bacterial and fungal
enzymes. The
enzymes used commercially in the food and detergent industries (ie. Savinase*,
Neutrase*,
Enzobake* or Alcalase*) available from Novo lnc. were found to have been
effective for
protein removal from tobacco. These enzymes were added to the solution in the
concentration range 0.1% to 5% w/w of the tobacco material.
*Trade-mark
The above described processes primarily rely on enzymes to remove protein from
tobacco material. Disadvantages arise from the use of such enzymatic compounds
and
agents. In particular, enzymes are expensive, pH sensitive, and degrade
proteins into amino
acids which tend to remain with the tobacco material. It is also thought that
enzymatic
compounds leave residues on tobacco material after processing. Additionally,
special
handling requirements and the additional process step of inactivating the
enzymes (i.e.
steam, autoclave, salt wash) cause the process to incur additional expenses.
Furthermore,
microbial agents used in treating tobacco tend to cause unwanted reactions
that generate
undesirable by-products.
Another current processes used to reduce nitrogen content in tobacco material
employs the use of an alkali or caustic solution. Poulose et al. (U.S. Pat.
No. 4,716,911)
also realized the disadvantage using protease enzymes and proposed using
either an alkali or
a combination of a protease and a non-protease depolymerase to effect protein
removal in an
overall processing scheme similar to that of Gaisch et al. However, it was
found that alkaline
solutions at the strengths quoted by Poulose et al. may have a deleterious
effect on the
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physical structure of the tobacco. Moreover, the use of a protease combined
with a
depolymerase may not be an economical approach to protein removal.
Mua, et al. (U.S. Pat. No. 6,508,254) relates to a method for providing a
reconstituted tobacco material having a reduced nitrogenous content without
having the
problems associated with the use of enzymes. In Mua, et al. the tobacco
material in the
form of flue cured and burley whole leaf, stems, fines, lamina or scraps,
and/or burley
stems was first contacted with an aqueous solvent. The resulting liquid
extract was then
separated from the tobacco fiber portion. The tobacco fiber portion was then
contacted
with a solution containing sodium acetate and/or sodium hydroxide and/or
potassium
hydroxide. This solution was also separated from the tobacco fiber portion.
The tobacco
fiber portion may then have been washed, refined and processed into
reconstituted
tobacco sheets. The liquid extract from the aqueous solvent extraction may
have been
concentrated and added back to the sheets.
There is a need to provide an economically competitive process by which the
nitrogen content of smoking material may be reduced without leaving residues
or
undesirable by-products and remains in a form that can be processed into paper
or
bandcast. This process must provide for an efficient and effective reduction
of proteins
and other nitrogenous compounds. It is desirable to provide a technique for
protein
reduction in smoking materials which does not cause a physical degradation of
the
tobacco structure and is economical and efficient.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a method of making a smoking material with
reduced
levels of nitrogenous compounds comprising: (a) contacting a tobacco material
with an
aqueous solvent to provide an aqueous tobacco extract and a tobacco fiber
portion; (b)
separating said aqueous tobacco extract from said tobacco fiber portion; (c)
refining said
tobacco fiber portion forming a refined tobacco material; (d) digesting said
refined
tobacco material; and (e) mixing said refined tobacco material with a
cellulose
containing material.
The present invention also provides a method of making a tobacco containing
material with reduced levels of nitrogenous compounds comprising: (a)
contacting a
tobacco material with a first aqueous solvent to provide an aqueous tobacco
extract and a
tobacco fiber portion; (b) separating said aqueous tobacco extract from said
tobacco fiber
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portion; (c) refining said tobacco fiber portion; (d) contacting at a
temperature from
about 170 F to 190 F said tobacco fiber portion with a solution containing a
compound
selected from the group consisting of sodium hydroxide and potassium
hydroxide,
wherein said solution contains said compound in a concentration about 1.25% to
12%
(w/v) of said solution; (e) separating said solution from said tobacco fiber
portion; and (f)
mixing said tobacco fiber portion with cellulose fibers.
The present invention relates to a method for providing a reconstituted
tobacco
containing material having a reduced nitrogenous content. The process starts
with flue
cured and/or burley tobacco in the form of whole leaf, stems, fines, lamina or
scraps. The
tobacco
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material is first contacted with an aqueous solvent. The resulting liquid
extract is separated
from the tobacco fiber portion. The tobacco fiber portion is then processed
according to the
present invention. The weak extract liquid (WEL) may be discarded, processed
and/or
concentrated and added back to the processed fiber portion.
The tobacco fiber portion is then refined and optionally digested with an
alkali
solution. The resulting tobacco material is then mixed with cellulose fibers
and optionally
inert materials. The inert materials may be inorganic or organic. The
inorganic inert material
that may be mixed with the tobacco fibers and cellulose includes CaCO3, MgO,
MgCO3 and
combinations thereof. The organic inert materials that may be mixed with the
tobacco fibers
and cellulose include chitosan, liposan and combinations thereof.
Additionally, both the
organic and inorganic inert materials may be mixed together with the tobacco
and cellulose
material. These combined materials may then be cast into sheet via a
papermaking process or
a binder and a humectant may be added and the material cast into sheet via
bandcast sheet
processing. The inert materials may include up to 20% of the finished sheet
produced by the
present invention. The tobacco fiber portion may make up to 50% of the
finished sheet
produced by the present invention. Advantageously, the finished sheet includes
between
approximately 10% to 50% tobacco.
The liquid extract or WEL from the aqueous solvent extraction may be discarded
or
added back to the fiber portion. If the WEL is to be added back to the fiber
portion, it may be
processed and/or concentrated. If the smoking material is to be cast into
sheet by a paper
making process, then the WEL is added back directly to the formed sheet. If
the smoking
material is to be cast into sheet by a bandcast process, then the WEL is added
back just prior
to the bandcast sheet processing. These finished sheets may then be used in
smoking articles,
such as cigarettes. The reduction of nitrogenous compounds in the smoking
material
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provides for improved smokability and a reduction in nitrogen containing
pyrolitic
products emitted from smoking articles which contain the tobacco material.
The present invention provides a method of making a reconstituted tobacco
material with reduced levels of nitrogenous compounds.
More particularly, the present invention is directed to a method for reducing
the
nitrogenous content of a smoking material. A better understanding of the
present
invention will be realized from the hereafter processes and the Examples
following such
description.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic of the process steps representative of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a preferred method of carrying out the nitrogen reduction process of the
present invention, tobacco materials 10 in the form of flue cured and/or
burley stems,
scraps, fines, and cut lamina are contacted at process station 11 with an
aqueous solvent,
such as water, at a temperature of about 60 C to 90 C for about 0.25 to 1
hour. The
contacting of the tobacco with an aqueous solvent, process station 11, may be
conducted
in a tank or similar mixing vessel in which the solvent and tobacco are heated
and may
be agitated or stirred. The resulting aqueous tobacco extract or weak extract
liquid
(WEL), containing flavor compounds, is separated from the tobacco fiber
portion at
process station 12. The tobacco/solvent mixture formed at process station 11
is then
pumped into a centrifuge from the mixing vessel and centrifugally separated or
alternatively the mixture may be filtered to remove the tobacco fiber portion
17 from the
WEL 13 at process station 12. The WEL 13 may be reserved for reapplication to
the
fiber portion 17 with or without separate processing 14. In one embodiment,
the WEL 13
may be deproteinated by contacting it with a solid phase adsorbent at process
station 14.
A solid phase adsorbent, such as a bentonite and carbon containing adsorbent,
is mixed
with the WEL 13 in a vessel and then separated therefrom by centrifugation, or
a similar
separation process well known in the art. The WEL 13, whether treated at
process station
14 or untreated, containing flavor compounds may then be concentrated at
process
station 16 by vacuum evaporation. Alternatively, the WEL 13 may be discarded
as
shown at process station 15.
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The tobacco fiber portion 17 may undergo several alternative processes. The
tobacco fiber portion 17 may be refined and digested at process station 18.
The refining
process at process station 18 consists of fiberizing or breaking down the
tobacco into
smaller fibers. The digestion process at process station 18 consists of adding
one part of
the refined tobacco to about eight parts of an alkali solution having about
1.25 % to 12 %
NaOH or KOH. The tobacco is digested in the alkali solution at about 170 F to
190 F
for up to 3 hours. Alternatively, digestion may be accomplished by autoclaving
the
tobacco at about 120 C for about 15 to 30 minutes at about 17 to 27 psig. The
resulting
tobacco material is then mixed with cellulose fibers and optionally inert
materials at
process station 19. Tobacco may make up to 50% of the sheet formed at process
station
21. Advantageously, tobacco will make up between about 10% to 50% of the sheet
formed at process station 21. The optional inert materials at process station
19 may be
inorganic or organic. The inorganic inert materials that may be mixed with the
tobacco
fibers and cellulose at process station 19 include CaCO3, MgO, MgCO3 and
combinations thereof. The organic inert materials that may be mixed with the
tobacco
fibers and cellulose at process station 19 include chitosan, liposan and
combinations
thereof. Additionally, both the organic and inorganic inert materials may be
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mixed together with the tobacco and cellulose material at process station 19.
The inert
materials added at process station 19 may include up to 20% of the sheet
formed at process
station 21. These combined materials may then be mixed with the WEL 13,
whether treated
14, untreated 13 and/or concentrated 16. At process station 20 a binder and
humectant is
added to the mixture. The mixture resulting from process station 20 is then
cast into sheets
via a bandcast process at process station 21. The sheets resulting from
process station 21 is
then cut and added to tobacco producing a tobacco blend at process station 34.
Alternatively, the tobacco fiber portion may be refined at process station 22
and
mixed with cellulose fibers and optionally inert materials at process station
23. The optional
inert materials at process station 23 may be inorganic or organic. The
inorganic inert
materials that may be mixed with the tobacco fibers and cellulose at process
station 23
include CaCO3, MgO, MgCO3 and combinations thereof. The organic inert
materials that
may be mixed with the tobacco fibers and cellulose at process station 23
include chitosan,
liposan, and combinations thereof. Additionally, both the organic and
inorganic inert
materials may be mixed together with the tobacco and cellulose material at
process station
23. The inert materials may include up to 20% of the bandcast sheet formed at
process
station 25. The tobacco fiber portion may make up to 50% of the bandcast sheet
formed at
process station 25. These combined materials may optionally be mixed with the
WEL 13,
whether treated 14, untreated 13 and/or concentrated 16. At process station 24
a binder and
humectant is added to the mixture. The mixture resulting from process station
24 is then cast
into sheets via a bandcast process at process station 25. The sheets resulting
from process
station 25 are then cut and added to tobacco producing a tobacco blend at
process station 34.
In addition to the embodiments incorporating a bandcast step in the present
invention
the process of the present invention may produce sheet via a paper making
process. Two
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embodiments of the present invention are shown in Figure 1 to incorporate a
paper making
process station.
In one embodiment the tobacco fiber portion 17 is refined and digested at
process
station 26. The refined and digested tobacco fiber is then mixed with
cellulose fibers and
optionally inert materials at process station 27. The optional inert materials
at process station
27 may be inorganic or organic. The inorganic inert materials that may be
mixed with the
tobacco fibers and cellulose at process station 27 include CaCO3, MgO, MgCO3
and
combinations thereof. The organic inert materials that may be mixed with the
tobacco fibers
and cellulose at process station 27 include chitosan, liposan, and
combinations thereof.
Additionally, both the organic and inorganic inert materials may be mixed
together with the
tobacco and cellulose material at process station 27. The inert materials may
include up to
20% of the sheet formed at process station 28. The tobacco fiber portion may
make up to
50% of the sheet formed at process station 28. These combined materials
resulting from
process station 27 are then made into sheets via a paper making process at
process station 28.
The paper sheet resulting from process station 28 may then have the WEL 13,
whether treated
14, untreated 13 and/or concentrated 16 added back at process station 29. The
paper sheets
resulting from process station 29 are then cut and added to tobacco producing
a tobacco blend
at process station 34.
In another embodiment incorporating a paper making process the tobacco fiber
portion 17 is first refined at process station 30. The refined tobacco fiber
is then mixed with
cellulose fibers and optionally inert materials at process station 31. The
optional inert
materials at process station 31 may be inorganic or organic. The inorganic
inert materials
that may be mixed with the tobacco fibers and cellulose at process station 31
include CaCO3,
MgO, MgCO3 and combinations thereof. The organic inert materials that may be
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with the tobacco fibers and cellulose at process station 31 include chitosan,
liposan, and
combinations thereof. Additionally, both the organic and inorganic inert
materials may be
mixed together with the tobacco and cellulose material at process station 31.
The inert
materials may include up to 20% of the sheet formed at process station 32. The
tobacco fiber
portion may make up to 50% of the sheet formed at process station 32. These
combined
materials resulting from process station 31 is then made into sheets via a
paper making
process at process station 32. The paper sheet resulting from process station
32 may then
have the WEL 13, whether treated 14, untreated 13 and/or concentrated 16 added
back at
process station 33. The paper sheets resulting from process station 33 is then
cut and added
to tobacco producing a tobacco blend at process station 34.
The following Examples are incorporated herein to illustrate the present
invention
with no intention of being unduly limited thereby.
EXAMPLES 1-4
Example 1:
Burley tobacco in the form of whole leaf, stems, fines, lamina and scraps was
first
extracted with water. This was accomplished by placing approximately 1 part of
tobacco
material into a vessel having approximately 11 parts of water. The tobacco and
water were
contacted at about 160 F for about 30 minutes. The tobacco and water was
periodically
mixed during this extraction. The tobacco and extract were then separated by
basket
centrifuge forming a WEL and an extracted tobacco fiber. The WEL was
discarded, while
the fiber was refined or fiberized.
A portion of the extracted burley tobacco fiber was formed into sheet with a
MKS
sheet former and analyzed to provide control data. Another portion of the
fiber was treated
with Savinase* in accordance with the process in DeGrandpre et al. (U.S. Pat.
No.
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5,311,886). This was accomplished by placing approximately 3.8 to 4.8 kg of
extracted
tobacco fiber into solution having approximately 200 ml. Savinase*, 40 g NaOH
and 114 L
water. The tobacco fiber was digested in the solution at about 57 C for about
30 minutes
while the solution was periodically stirred. The Savinase* solution was then
separated from
the tobacco fiber by basket centrifuge and discarded. The Savinase* treated
burley tobacco
fiber was rinsed three times with a salt solution having 1.84 kg NaCI in 80 L
water. The
rinsed burley tobacco fiber was autoclaved (heated to 121 C and held for 15
min, at 17 psig)
to inactivate any remaining enzymes and formed into sheet with a MMS sheet
former and
analyzed for Hoffinann anlaytes.
A separate portion of the burley tobacco fiber was treated with alkali in
accordance
with Mua et al. This was accomplished by adding 1 part of tobacco fiber having
about 60%
moisture to about 8 parts of an alkali solution having about 2.5 % NaOH. The
tobacco was
digested in the alkali solution at about 190 F for about 2 hours. The tobacco
fiber was then
separated by basket centrifuge and the alkali solution was discarded. Water
was then added
to the digested tobacco fiber after which it was refined and formed into sheet
with a MKS
sheet former and analyzed for Hoffinann analytes.
Yet another portion of the burley tobacco fiber was processed by the method
claimed
in the present invention. This was accomplished by adding cellulose pulp and
Ca03 filler to
the extracted tobacco fiber forming a tobacco containing material having
approximately 25%
tobacco. This tobacco containing material was then formed into sheets with a
MKS sheet
former and the resulting sheets were analyzed for Hoffmann analytes. The
analytical results
of this example are tabulated below.
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Protein (nitrogen) and Other Hoffmann Analyte Precursor Removal / Reduction
from
Burley Base Sheet
Reconstitution Total Protein Total Polyphenois Alkaloids Nitrate
process nitrogen (% dwb) TSNAs (% dwb) (% dwb) (% dwb)
(% dwb) (ppm) Chiorogenic Rutin Scopoletin
acid
Washed burley 3.57 20.44 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
fiber- Control
Burley fiber- 1.63 9.38 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Savinase* treated
Burley fiber- 2.5% 2.49 14.38 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
alkali treated
Burley- with 25% 0.97 1.33 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
tobacco fiber +
cellulose and inert
filler
The present invention was shown to substantially reduce the total nitrogen and
protein
content in the smoking material. Neither the Savinase* nor the alkali treated
tobacco lowered
the nitrogen and protein content of the smoking material near the 73% and 93%
reductions as
obtained in this example.
Example 2:
A mixture of tobacco having flue and burley tobacco in a ratio of about one to
one
was processed in accordance with the procedures in Example 1 to obtain a
washed flue /
burley control, Savinase* treated, and alkali treated tobacco sheets. The
flue/burley tobacco
was processed in accordance with the present invention where a finished base
sheet was
produced having 15% tobacco and separately 50% tobacco. These base sheets were
analyzed
for Hoffinann ayalytes and the results are as shown below.
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Protein (nitrogen) and other Hoffmann analyte precursor removal/reduction
from Flue/Burley Base Sheet
Reconstitution Total Protein Total Polyphenols Alkaloids Nitrate
process nitrogen (% dwb) TSNAs (% dwb) (% dwb) (% dwb)
(% dwb) (ppm) Chlorogenic Rutin Scopoletin
acid
Washed 1.48 8.50 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
flue/burley-
Control
Flue/burley - 0.56 3.38 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Savinase*
treated
Flue/burley- alkali 0.76 4.06 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
treated
Flue/burley- with 0.21 1.06 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
15% tobacco
fiber + wood pulp
+ inert filler
Flue/burley- with 0.75 4.56 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
50% tobacco
fiber + wood pulp
+ inert filler
The present invention was again shown to substantially reduce the total
nitrogen and
protein content in the smoking material. Neither the Savinase* nor the alkali
treated tobacco
lowered the nitrogen and protein content of the smoking material near the 86%
and 88%
reductions as obtained in this example having 15% tobacco fiber.
Example 3:
Burley tobacco was processed in accordance with the procedures in Example 1 to
obtain a washed burley control, Savinase* treated, and alkali treated tobacco
sheets.
However, in this example the WEL was treated with an adsorbent having
bentonite and
carbon, to remove nitrogenous compounds, and the treated WEL was added back to
the
tobacco sheets. The burley tobacco containing sheets were processed in
accordance with the
present invention where a finished sheet was produced having 50% tobacco (15%
tobacco
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fiber + 35% concentrated extract). These finished sheets were analyzed for
Hoffinann
ayalytes and the results are as shown below.
Protein (nitrogen) and other Hoffmann analyte precursor removal/reduction
from Burley Finish Sheet
Reconstitution Total Protein Total Polyphenols Alkaloids Nitrate
process nitrogen (% TSNAs (% dwb) (% dwb) (% dwb)
(% dwb) dwb) (ppm) Chlorogenic Rutin Scopoletin
acid
Washed burley- 4.27 13.94 7.01 0.18 >0.5 0.02 1.13 1.41
Control + regular
burley extract
Burley fiber- 2.03 6.38 1.55 <0.1 <0.1 <0.1 0.88 1.23
Savinase*
treated + burley
treated extract
Burley fiber- 3.19 7.38 1.64 <0.1 <0.1 <0.1 0.90 1.43
2.5% alkali
treated + burley
treated extract
Burley- with 1.23 1.75 1.65 <0.1 <0.1 <0.1 0.89 1.41
20% tobacco
fiber + burley
treated extract
The present invention was again shown to substantially reduce the total
nitrogen and
protein content in the smoking material. Neither the Savinase* nor the alkali
treated tobacco
lowered the nitrogen and protein content of the smoking material near the 71 %
and 87%
reductions as obtained in this example having 50% tobacco.
Example 4:
A mixture of tobacco having flue and burley tobacco in a ratio of about one to
one
was processed in accordance with the procedures in Example 3 to obtain a
washed burley
control, Savinase* treated, and alkali treated tobacco sheets. The flue/burley
tobacco
containing sheets were processed in accordance with the present invention
where a finished
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sheet was produced having 65% and 45% tobacco. These finished sheets were
analyzed for
Hoffinann ayalytes and the results are as shown below.
Protein (nitrogen) and other Hoffmann analyte precursor removal/reduction
from Flue/Burley Finish Sheet
Reconstitution Total Protein Total Polyphenois Alkaloids Nitrate
process nitrogen (% dwb) TSNAs (% dwb) (% dwb) (% dwb)
(% dwb) (ppm) Chlorogenic Rutin Scopoletin
acid
Flue/burley- 4.66 5.56 17.80 0.03 0.02 0.01 3.4 2.10
Control + regular
burley extract
Flue/burley- 2.29 2.38 3.24 0.00 0.00 0.00 1.81 1.95
Savinase* +
treated burley
extract
Flue/burley -alkali 3.01 2.56 3.41 0.00 0.00 0.00 1.58 1.53
+ treated burley
extract
Flue/Burley-with 3.22 3.00 2.98 0.00 0.00 0.00 1.76 1.63
50% tobacco
fiber + burley
treated extract
Flue/Burley-with 1.09 1.38 3.04 0.00 0.00 0.00 1.79 1.53
15% tobacco
fiber + burley
treated extract
The process of the present invention substantially reduced the total nitrogen
and
protein content in the smoking material. Neither the Savinase* nor the alkali
treated tobacco
lowered the nitrogen and protein content of the smoking material near the 77%
and 75%
reductions as obtained in this example having 45% tobacco.
The aforementioned examples show that the present invention substantially
reduces
total nitrogen and protein content of smoking materials. Additionally, the
problems
associated with the prior art of having enzyme residues in the smoking
material and having
problems in the paper making process have been resolved in the present
invention.
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