Abstract:
Methods of making reconstituted tobacco include contacting a mixture including tobacco pulp with one or more fluid streams including one or more peroxides (e.g., hydrogen peroxide), recovering one or more fluids from the tobacco pulp mixture, and reusing the recovered fluids in at least one subsequent tobacco pulp contacting step. In some cases, methods provided herein can recover one or more fluids including one or more peroxides, such that the at least one subsequent tobacco pulp contacting step includes contacting tobacco pulp with a fluid including one or more peroxides.

Description:
FIELD 
       [0001]    This disclosure generally relates to the use of peroxides (e.g., hydrogen peroxide) to limit the formation of biofilms and tobacco-specific nitrosamines (TSNAs). 
       BACKGROUND 
       [0002]    During the processing and manufacturing of tobacco products, tobacco by-products such as tobacco stems, leaf scraps, and tobacco dust produced during the manufacturing process (i.e., stemming, aging, blending, cutting, drying, cooling, screening, shaping and packaging) can be recycled to reclaim useful tobacco content. In the past, such tobacco by-products have been formed into what is known in the industry as reconstituted tobacco sheets. In the manufacturing of smoking articles and particularly cigarettes, it is common to use sheets of reconstituted tobacco. In some cases, reconstituted tobacco sheets can be used as a wrapper. In some cases, reconstituted tobacco sheets can be cut into strips and blended with tobacco. In some cases, tobacco pulp is suspended, cast, and dried to form a sheet of reconstituted tobacco. In some cases, processes for manufacturing reconstituted tobacco sheets use a machine in which water is drained from a fibrous slurry of tobacco particles, and sheet that is formed is subsequently treated and dried. 
       SUMMARY 
       [0003]    Methods of making reconstituted tobacco provided herein can include contacting a mixture including tobacco pulp with one or more fluid stream including one or more peroxides (e.g., hydrogen peroxide), recovering one or more fluids from the tobacco pulp mixture, and reusing the recovered fluids in at least one subsequent tobacco pulp contacting step. In some cases, methods provided herein can recover one or more fluids including one or more peroxides, such that the at least one subsequent tobacco pulp contacting step includes contacting tobacco pulp with a fluid including one or more peroxides. In some cases, the one or more fluid streams have a peroxide concentration of at least 60 ppm. In some cases, the one or more fluid streams have a peroxide concentration of at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 400 ppm, or at least 500 ppm. In some cases, a peroxide concentration in the recovered fluid used in the at least one subsequent tobacco pulp contacting step is within plus or minus 50% of the peroxide concentration of the one or more fluid streams. In some cases, the recovered fluids can be supplemented with fresh fluids and/or one or more fresh peroxides prior to the at least one subsequent tobacco pulp contacting step in order to maintain a desired hydrogen peroxide concentration. 
         [0004]    Methods of making reconstituted tobacco provided herein can, in some cases, recycle aqueous fluid streams contacting tobacco pulp in order to produce a recycled aqueous solution of soluble tobacco components. In some cases, methods provided herein can include one or more peroxides (e.g., hydrogen peroxide) in the recycled aqueous solution. In some cases, the recycled aqueous solution is treated between subsequent tobacco pulp contacting steps to maintain a desired peroxide concentration. In some cases, the recycled aqueous solution is maintained at a peroxide concentration of at least 60 ppm, at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 400 ppm, or at least 500 ppm. 
         [0005]    Methods of making reconstituted tobacco provided herein can, in some cases, agitate tobacco by-products with an aqueous pulping fluid in order to form a tobacco pulp suspension. In some cases, methods provided herein can include one or more peroxides (e.g., hydrogen peroxide) in the aqueous pulping fluid. The tobacco pulp suspension can be separated into a tobacco pulp mixture and a liquid extract. In some cases, the liquid extract can include one or more peroxides. In some cases, the liquid extract can be concentrated and applied to a cast sheet of tobacco pulp. In some cases, the liquid extract can be treated to have nitrates removed and applied to a sheet of tobacco pulp. In some cases, the liquid extract can be maintained at a desired peroxide concentration during storage after separation from the tobacco pulp and prior to application to a sheet of tobacco pulp. In some cases, the stored liquid extract is maintained at a peroxide concentration of at least 60 ppm, at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 400 ppm, or at least 500 ppm. 
         [0006]    In some cases, methods provided herein can inhibit the growth of biofilm producing bacteria, such as  Geobacillus stearothermophilus , in one or more fluid streams used to produce a reconstituted tobacco. For example, systems including recycled streams without the addition of peroxides can have a population of  Geobacillus stearothermophilus  of about 10,000 cfl/ml, which can produce a significant amount of biofilm in the system. In some cases, methods provided herein can control a population of a biofilm producing bacteria below a desired threshold. In some cases, a population of  Geobacillus stearothermophilus  in methods and systems provided herein can be maintained below a threshold of 5,000 clf/ml; below a threshold of 1,000 cfl/ml; below a threshold of 500 cfl/ml; below a threshold of 100 cfl/ml; below a threshold of 50 cfl/ml; below a threshold of 20 cfl/ml; below a threshold of 10 cfl/ml; or below a threshold of 5 cfl/ml. In some cases, a population of a biofilm producing bacteria, such as  Geobacillus stearothermophilus , can be maintained below a detectable limit. For example, biofilm producing bacteria can proliferate in one or more streams used in traditional methods of reconstituting tobacco, especially recycled streams. Biofilm producing bacteria can produce a solid sludge that can intermix with tobacco pulp and disrupt a sheet casting process. For example, deposits of biofilm on a casting felt surface can inhibit tobacco pulp from being deposited in that location, which can result in perforations in a resulting reconstituted tobacco sheet. Perforations in a reconstituted tobacco sheet can reduce tear resistance, and thus complicate handling of the reconstituted tobacco sheet. Physically removing a biofilm (e.g., by flushing and/or skimming a tank holding a recycled aqueous solution and/or liquid extract) can result in a loss of tobacco solubles, increase an amount of fresh inputs needed, and/or increase the time needed to produce reconstituted tobacco sheets. 
         [0007]    In addition to inhibiting and/or controlling biofilm producing bacteria, peroxides can additionally inhibit/control the growth of the entire bacterial population, including bacteria that can form to produce tobacco-specific nitrosamines (TSNAs). In some cases, methods provided herein can include one or more peroxides one or more fluid streams to inhibit the growth of bacteria that produce TSNAs. TSNAs are nitrosation products of secondary and tertiary alkaloid amines in tobacco. TSNAs are the result of a chemical reaction between tobacco alkaloids, such as nicotine and nornicotine, and unstable NO x  radicals (e.g., NO 2 , N 2 O 3 , and/or N 2 O 4 ), which can accumulate as a result of nitrate reduction by bacteria. TSNAs are known in the art and include, for example, N′-nitrosonornicotine (NNN), 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), N′-nitrosoanabasine (NAB), and 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanal (NNAL). Microbes on or in the tobacco plant before, during, or after curing can be responsible for the formation of nitrite, the predominant NO x  precursor in the formation of TSNAs (Bush et al.  Recent Advances in Tobacco Science.  27:23-46 (2001)). In some cases, the use of one or more peroxides (e.g., hydrogen peroxide) in a tobacco pulp suspension can reduce a number of bacteria producing unstable NO x  radicals, which can limit a formation of TSNAs in reconstituted tobacco sheets after production. In some cases, reconstituted tobacco sheets provided herein can have less than 50 ppm of TSNAs, less than 25 ppm of TSNAs, less than 20 ppm of TSNAs, or less than 15 ppm of TSNAs. 
         [0008]    In some cases, methods provided herein include hydrogen peroxide in one or more fluid streams contacting tobacco pulp in order to limit and/or control a bacterial population within the one or more fluid streams. In some cases, hydrogen peroxide can be separated from tobacco pulp with water by pressing, evaporation, and/or decomposition. Hydrogen peroxide is soluble in water and evaporates at a rate similar to water, thus hydrogen peroxide can be used in fluid streams contacting tobacco pulp without building up a hydrogen peroxide concentration in the tobacco pulp. In some cases, hydrogen peroxide can decompose into oxygen and water due to heat and/or time. In some cases, a heated drying roller can be applied to a reconstituted tobacco sheet including residual hydrogen peroxide to cause the hydrogen peroxide to decompose into oxygen and water. In some cases, a reconstituted tobacco sheet including residual hydrogen peroxide can be stored for a predetermined amount of time in order to reduce a residual hydrogen peroxide concentration below a predetermined limit. 
         [0009]    Methods provided herein can improve the quality of reconstituted tobacco sheets, increase the productivity, and/or reduce the costs of producing reconstituted tobacco sheets. In some cases, hydrogen peroxide acts as a processing aid that can control the population of bacteria within recirculated streams such that unwanted bacterial by-products (e.g., biofilm, TSNAs) are minimized. A reduced production of biofilm can increase productivity and reduce cost by avoiding time-consuming and/or product-wasting processes used to physically remove the biofilm. Peroxides can further improve quality by eliminating bacteria that can produce TSNAs. Applicants have also found that the use of hydrogen peroxide in processes described herein does not negatively affect the taste of the reconstituted tobacco sheet. 
         [0010]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the methods and compositions of matter belong. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the methods and compositions of matter, suitable methods and materials are described below. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a flow chart illustrating an exemplary embodiment of a method of making reconstituted tobacco sheet provided herein. 
           [0012]      FIG. 2  depicts a biofilm or sludge produced by  Geobacillus stearothermophilus.    
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Methods of making reconstituted tobacco provided herein include one or more peroxides (e.g., hydrogen peroxide) in one or more fluid streams contacting tobacco pulp to control and/or reduce a bacterial population in those streams to improve product quality, increase process efficiency, and/or reduce costs. For example, in some processes of making reconstituted tobacco, water and other fluids can be mixed with tobacco by-products in a pulper to create a tobacco pulp suspension. In some cases, liquid (e.g., a liquid including water and tobacco soluble) can be separated from the tobacco pulp, optionally concentrated and/or nitrates removed, and added back to a cast sheet of tobacco pulp. In some cases, tobacco pulp can be processed with a second recycled fluid stream prior to casting a sheet of tobacco pulp. In methods provided herein, fluid streams (such as the water added to the pulper and/or the second recycled fluid stream) can include one or more peroxides to control populations of various bacteria within each fluid stream. In some cases, methods provided herein can control the population of biofilm producing bacteria, such as  Geobacillus stearothermophilus , and/or TSNA producing bacteria. 
         [0014]      FIG. 1  is a flow chart illustrating an exemplary embodiment of a method of making reconstituted tobacco sheet provided herein. As shown, pulper dilution  103  and blended tobacco  105  can be mixed via streams  102  and  106 , respectively, for pulping  101 . Pulping  101  can be conducted in a superpulper, which can rehydrate blended tobacco  105  and form a tobacco pulp suspension. In some cases, blended tobacco  105  can have an average residence time in a superpulper of at least 10 minutes, at least 20 minutes, at least 30 minutes, at least 40 minutes, or at least 50 minutes. In some cases, an average residence time in a superpulper is between 10 minutes and 4 hours, between 20 minutes and 3 hours, between 30 minutes and 2 hours, between 40 minutes and 1 hour, or about 45 minutes. The superpulper can be operated at a temperature of between 20° C. and 100° C., between 30° C. and 90° C., between 40° C. and 75° C., between 50° C. and 65° C., or between 55° C. and 60° C. A tobacco pulp suspension  110  flows to one or more presses  111  to separate liquids  112  from the tobacco pulp  114 . In some cases, a stream  104  of liquid from the presses  111  can be cycled back to the pulper dilution  103  tank. 
         [0015]    Pulper dilution  103  can be an aqueous solution including one or more peroxides. In some cases, pulper dilution  103  can include hydrogen peroxide and water. In some cases, pulper dilution  103  can consist of water and hydrogen peroxide. In some cases, pulper dilution  103  can include tobacco solubles, flavorants, and other additives. In some cases, a desired concentration of tobacco solubles can be achieved by controlling a recycled flow  104  of liquid from the presses  111 . In some cases, pulper dilution can have a peroxide concentration of at least 60 ppm, at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 400 ppm, at least 500 ppm, at least 1,000 ppm, or at least 5,000 ppm. In some cases, the pulper dilution can have a peroxide concentration of less than 10 molar percent, less than 5 molar percent, less than 1 molar percent, less than 5,000 ppm, less than 1,000 ppm, or less than 500 ppm. In some cases, pulper dilution can have a peroxide concentration of between 60 ppm and 10 molar percent, between 100 ppm and 5 molar percent, between 200 ppm and 1 molar percent, between 300 ppm ant 5,000 ppm, between 400 ppm and 1,000 ppm, or about 500 ppm. A presence of peroxides in pulper dilution  103  and stream  104  can control populations of bacteria in the dilution streams and any associated holding tank. Blended tobacco  105  can be any suitable mixture of tobacco and optionally non-tobacco cellulosic materials. By “tobacco” it is meant a part, e.g., leaves, and stems, of a member of the genus  Nicotiana  that has been processed. Exemplary species of tobacco include  N. rustica, N. tabacum, N. tomentosiformis , and  N. sylvestris . In some cases, blended tobacco can include tobacco by-products from other tobacco processing operations. For example, tobacco by-products can include tobacco stems, leaf scraps, and tobacco dust produced during the manufacture of cigarettes, cigars, smokeless tobacco, and other tobacco products (i.e., stemming, aging, blending, cutting, drying, cooling, screening, shaping and packaging). In some cases, tobacco can be processed by heat treatment (e.g., cooking, steam treating, toasting), flavoring, enzyme treatment, fermenting, expansion and/or curing. In some cases, the tobacco can be unprocessed tobacco. Specific examples of suitable processed tobaccos include, dark air-cured, dark fire-cured, burley, and flue cured. The tobacco can, in some cases, be prepared from plants having less than 20 μg of DVT per cm2 of green leaf tissue. For example, the tobacco particles can be selected from the tobaccos described in U.S. Patent Publication No. 2008/0209586, which is hereby incorporated by reference. Tobacco compositions containing tobacco from such low-DVT varieties exhibits improved flavor characteristics in sensory panel evaluations when compared to tobacco or tobacco compositions that do not have reduced levels of DVTs. 
         [0016]    One or more presses  111  can separate tobacco pulp suspension  110  into a stream of liquid  112  and a mixture of dry and crushed tobacco pulp  114 . Liquid  112  can include tobacco extracts, one or more peroxides, and any other soluble additive used in the pulper dilution or present in the blended tobacco. In some cases, this initial extract is referred to as strong extract liquor (SEL). In some cases, the SEL can be further concentrated to form a concentrated extract liquor (CEL) and/or have nitrates removed. As shown, multiple stages  121 ,  123 ,  125 , and  127  can be used to purify and refine the SEL into de-nitrified concentrated extract liqueur (DNCEL). During production, SEL typically is held in a SEL tank for about 4 hours or less at temperatures that range from 51° C. to 77° C. Conditions in a typical SEL tank include, without limitation, a starting pH of 5.4 and a temperature that ranges from about 51° C. to about 76° C. A typical SEL tank contains about 10 4  CFU/ml natural microflora, and can have a nitrite content that ranges from about 5 ppm up to about 130 ppm, but processes described herein can reduce the microflora concentration to about or below 10 2  CFU/ml. During processing, a SEL tank is typically agitated at about 60 RPM to about 75 RPM (e.g., about 65 RPM to about 70 RPM, about 67 RPM). As shown, one or more centrifuges  121  (e.g., bird centrifuges) can be used to separate any remaining solids from the SEL, the remaining liquid  122  passes to any one or more evaporators  123  to remove water to form the CEL  124 , which can be passed to one or more crystallizers  125  adapted to crystallize nitrates. CEL  124  can be held in a CEL tank for 0 to 3 hours at temperatures that can range from 20° C. to 50° C. (e.g., 25° C. to 45° C., 30° C. to 40° C., about 35° C.). Crystallizing  125  the CEL produces a Denitrified Extract Liquor (DNCEL) mixed with crystals. An outflow stream  126  from the one or more crystallizers  125  can be passed to one or more centrifuges  127  (e.g., Sharples centrifuges) to remove the crystals to produce the DNCEL  128 , which is delivered to a size prep tank  129 . DNCEL can be stored in size prep tank  129  for up to 48 hours. The presence of one or more peroxides in this process, due to the use of one or more peroxides in the pulper dilution  103  and/or the pulping process  101 , can control the growth of bacteria and thus inhibit the production of TSNAs and/or biofilms in the DNCEL  128 . In some case, the peroxide is hydrogen peroxide, which can further be partially removed from the SEL/CEL in the one or more evaporators  123 . In some cases, a hydrogen peroxide concentration in DNCEL  128  can be within plus or minus 50% of a hydrogen peroxide concentration in SEL  112 . In some cases, a hydrogen peroxide concentration in DNCEL  128  can be within plus or minus 30% of a hydrogen peroxide concentration in SEL  112 . In some cases, a hydrogen peroxide concentration in DNCEL  128  can be within plus or minus 10% of a hydrogen peroxide concentration in SEL  112 . In size prep  129 , a thick size fraction  172  is removed and directed to a broke pulper  171 , combined with diluent  176  from tank  143  and broke,  00 C product  173  from flow  174 , and directed in flow  178  to a broke tank  107 , which is stored for delivery to pulping process  101 . The broke tank  107  can store product for startup processes or when a supply of blended tobacco  105  is not available. 
         [0017]    Dry and crushed tobacco pulp  114  can be further processed and cast into a sheet. As shown, tobacco pulp  114  is delivered through a series of press and discharge tanks where it is mixed and separated from recycled dilution before being cast into a sheet in casting process  161 . As shown, tobacco pulp  114  is mixed with dilution  144  from a tank  143  in one or more press discharge tanks  131  to make slurry  132 , which is delivered to a stock chest  133 . Output  134  from stock chest  133  is delivered to one or more refiners  135  for further mixing with dilution  144  from tank  143 . Output  136  from refiners  135  is delivered to a machine chest  151 , and a machine chest output  152  is mixed with additional dilution  146  from a tank  141  and delivered to a tickler headbox  153 . Output  154  from tickler headbox  53  is delivered to one or more tickler refiners  155 . Output  156  from the tickler refiners  155  is delivered to a stuff box  157 . Output  158  from stuff box  157  is delivered to fan pumps  159  where additional dilution  146  is added from tank  141 . Slurry  162  from fan pumps  159  is then delivered to a fourdrainer felt press  161  where a sheet of tobacco pulp is cast. Size  164  from size prep  129  is also sprayed onto the cast tobacco pulp sheet in fourdrainer felt press  161  to add back tobacco solubles. A cast sheet of tobacco pulp is then dried to form a reconstituted tobacco sheet. Pit drains  166  of fourdrainer felt press  161  recycle diluent back to tank  143 . Tray Water and Vaccum separators  168  of fourdrainer felt press  161  recycle diluent back to tank  141 , with overflow  142  from Strong Brown Water tank being delivered to the tank  143 . Accordingly, diluent mixed with tobacco pulp  114  during the various processing steps is subsequently separated from the tobacco pulp during the casting of a sheet of tobacco pulp and recycled back to a storage tank. 
         [0018]    Recycling diluent  144 ,  146 ,  166 , and  168  results in the diluent collecting tobacco soluble and other additives. Fresh water and/or peroxides (e.g., hydrogen peroxide) can be added to tank  141  or tank  143  during the process to make up for water losses and/or to control a peroxide concentration. A peroxide concentration in the diluent in tank  141  or tank  143  can be maintained at a predetermined concentration. In some cases, a peroxide concentration in tank  141  and/or tank  143  is maintained at a level of at least 60 ppm, at least 100 ppm, at least 200 ppm, at least 300 ppm, at least 400 ppm, at least 500 ppm, at least 1,000 ppm, or at least 5,000 ppm. In some cases, tank  141  and/or tank  143  are maintained at a temperature of between 60° C. and 73° C. In some cases, a peroxide concentration in tank  141  and/or tank  143  is maintained at a level of less than 10 molar percent, less than 5 molar percent, less than 1 molar percent, less than 5,000 ppm, less than 1,000 ppm, or less than 500 ppm. In some cases, a peroxide concentration in tank  141  and/or tank  143  is maintained at a level of between 60 ppm and 10 molar percent, between 100 ppm and 5 molar percent, between 200 ppm and 1 molar percent, between 300 ppm ant 5,000 ppm, between 400 ppm and 1,000 ppm, or about 500 ppm. A presence of peroxides in tank  141  and/or tank  143  and throughout the various processing of the tobacco pulp can control populations of bacteria in tank  141  and/or tank  143 . Controlling bacteria in the tank  141 , tank  143 , Pulping  101 , and other parts of the process can be important because bacteria can produce biofilms and/or produce TSNAs. 
         [0019]    In some cases, methods provided herein can inhibit the growth of biofilm producing bacteria, such as  Geobacillus stearothermophilus , in the tank  141 , tank  143 , Pulping  101 , and other parts of the process.  Geobacillus stearothermophilus  can produce a biofilm or sludge, such as that depicted in  FIG. 2 . Biofilm sludge, such as shown in  FIG. 2 , can become intermixed with tobacco pulp  114  during pulping  101 , during mixture with diluent  144  and  146 , and disrupt a sheet casting process  161 . For example, deposits of biofilm on a casting felt surface  161  can inhibit tobacco pulp from being deposited in that location, which can result in perforations in a resulting reconstituted tobacco sheet. Perforations in a reconstituted tobacco sheet can reduce tear resistance, and thus complicate handling of the reconstituted tobacco sheet. Physically removing a biofilm (e.g., by flushing and/or skimming tank  141  and/or tank  143 ) can result in a loss of tobacco soluble, increase an amount of fresh inputs needed, and/or increase the time needed to produce reconstituted tobacco sheets. 
         [0020]    In addition to inhibiting and/or controlling biofilm producing bacteria, peroxides can additionally inhibit/control the growth of the entire bacterial population, including bacteria that can form to produce TSNAs. In some cases, methods provided herein can include one or more peroxides in one or more fluid streams to inhibit the growth of bacteria that produce TSNAs. TSNAs are nitrosation products of secondary and tertiary alkaloid amines in tobacco. TSNAs are the result of a chemical reaction between tobacco alkaloids, such as nicotine and nornicotine, and unstable NO x  radicals (e.g., NO 2 , N 2 O 3 , and/or N 2 O 4 ), which can accumulate as a result of nitrate reduction by bacteria. TSNAs are known in the art and include, for example, N′-nitrosonornicotine (NNN), 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), N′-nitrosoanabasine (NAB), and 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanal (NNAL). Microbes on or in the tobacco plant before, during, or after curing can be responsible for the formation of nitrite, the predominant NO x  precursor in the formation of TSNAs (Bush et al.  Recent Advances in Tobacco Science.  27:23-46 (2001)). In some cases, the use of one or more peroxides (e.g., hydrogen peroxide) in a tobacco pulp suspension can reduce a number of bacteria producing unstable NO x  radicals, which can limit a formation of TSNAs in reconstituted tobacco sheets after production. 
         [0021]    In some cases, methods provided herein include hydrogen peroxide in one or more fluid streams contacting tobacco pulp in order limit and/or control a bacterial population within tank  141  and/or tank  143 . In some cases, hydrogen peroxide can be separated from tobacco pulp with water by pressing, evaporation, and/or decomposition. Hydrogen peroxide is soluble in water and evaporates at a rate similar to water, thus hydrogen peroxide can be used in fluid streams contacting tobacco pulp without building up a hydrogen peroxide concentration in the tobacco pulp. In some cases, hydrogen peroxide can decompose into oxygen and water due to heat and/or time. In some cases, a heated drying roller can be applied to a reconstituted tobacco sheet including residual hydrogen peroxide to cause the hydrogen peroxide to decompose into oxygen and water. In some cases, a reconstituted tobacco sheet including residual hydrogen peroxide can be stored for a predetermined amount of time in order to reduce a residual hydrogen peroxide concentration below a predetermined limit. 
       Other Embodiments 
       [0022]    It is to be understood that, while the invention has been described herein in conjunction with a number of different aspects, the foregoing description of the various aspects is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.