Smoking Product And Method Of Making Same

Abstract

A smoking product is prepared from waste beet pulp that may be used alone or may be blended with any desired proportion of tobacco. The process comprising the acid hydrolysis of the beet pulp to release beet pectins, and at least an alkaline earth treatment thereafter to cause cross-linking of the pectins and forming a binding agent for the exhausted beet matrix. Preferably a demethylation step on the released pectins is carried out prior to the cross-linking reaction. The final slurry is then dried by known procedures to form a smoking product.

Description

BACKGROUND OF THE INVENTION

Smoking materials have often been described where some or all of the tobacco was proposed to be replaced by various synthetic or natural products. Included in such proposals, at least as far as neutral products are concerned, were leaves from tress, vines or shrubs, leafy garden vegetables or herbs and even common weeds or grasses. In general, the primary purpose of trying such materials as a smoking product has been either to reduce costs or more often to find a substitute for a failing supply of tobacco caused by war-time conditions. However, such experiments in the past failed to yield a satisfactory smoking product capable of substituting for natural tobacco materials.

Research has continued in seeking a tobacco substitute for various other reasons. For example, not all the components naturally present in tobaccos grown under different climates or growing conditions yield a satisfactory product from a smoker's standpoint. Some have different burning characteristics producing products of combustion that unfavorably affect the smoke, and some may have an unsatisfactory flavor or aroma or an undesirable amount of nicotine content. Thus, the desire to eliminate unnecessary or undesirable tobacco components which have no favorable effect on the smoke from a taste and flavor aspect has led to a continued search for a satisfactory tobacco substitute. Additionally, of course, is the desire to find a low cost tobacco substitute.

The present invention relates to a new smoking material whereby a tailored smoking product is made from an inexpensive non-tobacco natural material and which is also free of many undesirable components and properties normally present in tobacco or earlier proposed tobacco substitutes.

The new smoking material which may replace all or at least part of tobacoo parts used in cigarettes or the like is derived from beet pulp. More particularly, it is obtained as a by-product of sugar beet processing after the sugar fractions have been extracted from the beets

The final product is a good tobacco substitute by virtue of its very low cost. It may be used alone or as a blending agent with tobacoo. Additionally it can be used to give substantially unlimited control over pyrolysis and the pyrolysis products.

Describing broadly a general sequence of operations for obtaining the desired product of the invention, exhausted or waste beet pulp in the form of dried beet cossettes are slurried in an aqueous medium with pectin releasing agents capable of hydrolyzing and solubilizing at least a portion of the pectinaceous content of the beets thereby releasing pectins from the beet pulp.

Following the hydrolysis, the beet mixture at this point may be refined by comminuting the hydrolyzed product in order to shorten the beet fibers. The comminuted beet mixture including the hydrolysis product is preferably then reacted with monovalent, basic dimethylation and saponification agents to replace methyl ester groups on the released pectins with more water-soluble reactive radicals to make them receptive to a following cross-linking reaction with divalent or trivalent cation compounds whereby the released pectins are cross-linked and precipitated from solution in gel-like form. These cross-linked pectins are excellent film-forming and binding agents for fibrous material, in this case, the beet residues.

It should be pointed out that one may carry out the demethylation or saponification and the cross-linking reaction separately, simultaneously or even omit the initial demethylation step. However, there is a notable improvement in handling properties as well as b burning characteristics when the demethylating-saponificating reaction is utilized. When both monovalent and polyvalent additions are made, the divalent or trivalent cross-linking ions should be present in higher concentration.

After the reactions are completed and the newly cross-linked pectinaceous film-forming components have been produced, the total aqueous reaction slurry, containing the products of reaction, the pectinaceous gels as binders or film-forms and the beet residues are extruded or laid down to produce a sheet by procedures which conserve water-solubles and are essentially similar to known methods used in forming reconstituted tobacco in dried form for subsequent production of a smoking filler.

Prior to shaping thproduct into the desired form, it is preferred to adjust the pH of the mixture at this point and, in addition, to supply desired substances to improve the general properties of the final product so that a proper flavor and aroma as well as the burning or combustion characteristics will approach that of a good tobaco filler. Thus, a preferred pH of the slurry before casting or other shaping should be in the neighborhood of about pH 5.5 to 6, if nicotine is part of the formulation, and since the mixture may be somewhat alkaline, a suitable organic acid, for example, citric acid may be used to bring the pH to the desired point and supply at the same time ions found in natural tobaccos. If the nicotine is omitted, pH adjustment is unnecessary. Additionally, one may add non-toxic salts, sugars, non-toxic plasticizers and if preferred, nicotine to the slurry prior to the shaping operation or these may be added at a later point after the final drying step, to yield specific and desirable properties to the final product.

Reverting to the described sequence of steps for a clearer understanding and for greater detail, the hydrolysis step is first carried out on exhausted and dried sugar beet pulp cossettes, a waste product of sugar beet refining, in which the beets, containing protopectins, are cooked with an agent capable of releasing beet pectins.

These protopectins have been found to have substantial similarities to tobacco protopectins in that they are water insoluble and comprise polygalacturonic acid molecules complexed with various multivalent groups acting as molecular cross-linkers. The beet pectins that are released by the hydrolysis step are water-soluble and in the cooking step the insoluble beet protopectins are hydrolyzed to water-soluble fragments consisting mainly or arabans, galactans, acetic acid, and the aforesaid water-soluble pectins.

The pectin-releasing agent utilized in the primary hydrolysis cooking step is a substance capable of reacting with and destroying the cross-links of the beet protopectins so that the pectins are capable of being released from the beet material. For the hydrolysis step mineral acids are preferred and particularly those acids are preferred whose anions will produce non-toxic salts which are normally found in tobacco. Among those acids useful in the present invention are such non-toxic mineral acids as hydrochloric, sulfuric or phosphoric acids. Organic acids found in tobacco such as citric or malic acid are also useful. While acids are the preferred materials for releasing pectins, other acidic substances capable of releasing the pectins may be used. Additionally, as a substitute for a mineral acid, one may use cation sequestering agents, a preferred agent in this category being diammonium hydrogen phosphate (DAP).

In the cooking step a pH in the range of about 1.0 to 6.0 is maintained, preferably in the range of about 1.5 to 4.5 or 5.0 at the start of the operation. During the cookign, the acidity may decrease from a highly acid point to a pH of about 3 or 4 but this will not affect the hydrolysis to any material extent. Proportions of pectin-releasing agent to the beet charge, namely redried beets cossettes, are in the range of about 1 to 4 parts to 100 parts by weight of beet material. It should be pointed out that one may use either single acids or a mixture of acids in the cooking operation. In the latter case, and as an example of a preferred mixture of acids that could be used for each pound of beet cossettes, one may have about 3 to 4 g of H.sub.3 PO.sub.4, about 9 to 10 g. of H.sub.2 SO.sub.4 and about 4 to 5 g of HCl

The cooking or hydrolysis step is carried out at a temperature from about 40.degree.C. to 110.degree.C., the lower temperature naturally requiring a longer period of time for the desired hydrolysis. At the higher temperature refluxing or a higher than atmospheric pressure is advisable. A preferred pectin releasing operation is to cook a dilute aqueous acid beet pulp slurry at a pH of about 1.9 to 2.9 for 1 to 4 hours, but preferably for the longer period of time, at a temperature of about 70.degree.C. to 90.degree.C. under generally normal pressures.

The formation of film-forming pectinaceous beet substances from the released pectins is carried out preferably by reacting the released pectins with monovalent and divalent cation compounds in that order. Oxides or hydroxides or even salts that are essentially basic may be used for demethylation and saponification. Monovalent compounds should be selected whose cations will supply the type normally found in tobacco and which are nevertheless capable of demethylating and saponifying the alkyl esters of the released pectins. As an example, and in order of decreasing cation preference, this would be potassium hydroxide, sodium hydroxide and ammonium hydroxide. As previously mentioned, strongly basic salts of these monovalent cations could be used instead of the hydroxides, as would be apparent to those skilled in the art.

The speed of the demethylation step has been found to vary depending on the basicity of the reaction medium. Thus, where alkali metal hydroxides are used in an amount which will provide a pH SOMEWHAT BELOW PH 12, the demethylation has been found to be rapid at the greatest pH, for example, pH 9.5, moderate at pH 8.5, and very slow at pH 7.0-8.0. Completion of the demthylation reaction is signalled by a slowing of the rate of drop of pH when it is about pH *.%. Control of the temperature in the neighborhood between 0.degree. and 25.degree.C. is usually necessary to limit deteriorating (chain scission) of the pectins by the alkaline medium. However, once the product is substantially demethylated, it is fairly stable. As an example, if one operates at a pH of about 9, with the temperature kept below 30.degree.C., the demethylation will take place satisfactorily in about 30 minutes.

Following the demethylation or simultaneously therewith, or even in place of the demethylation step, the released pectins in the beet slurry are changed to film-forming gels by means of a cross-linking reaction of the carboxylic acid groups of the pectins with multivalent cation oxides, hydroxides or their equivalent such as highly basic salts, of calcium or magnesium. As was mentioned before, the demethylation requires and alkaline condition. Cross-linking, in general, can occur at any pH above 3.0, but usually occurs most readily in the region between pH 5.0 and 9.0. The use of a multivalent cross-linking ion is an essential cation in the process of forming a final product.

Conditions for carrying out the cross-linking step on the released pectins are a pH in the range of about pH 5.0 to 9.0 supplied by adding basic compounds if necessary. The cross-linking reaction will proceed smoothly at temperatures preferably between 0.degree. and 100.degree.C. and more preferably at a temperature between 20.degree. and 60.degree.C.

After the completion of the cross-linking and precipitation of the film-forming gels, the slurry is essentially ready for casting or extrusion as a sheet or other shaping operation assuming it has those components deemed desirable which are normally associated with the production of a satisfactory smoking product. In general, however, a better product is achieved if the slurry after the cross-linking step, is brought to a pH in the neighborhood of about pH 5 to 6. This may require the addition of an acid, and preferably an organic acid that desirably also supplies ions normally found in most tobaccos. Such an acid may be citric, maleic or other lower aliphatic carboxylic acids, or where there is a need for more inorganic ion, a mineral acid could be used. The carboxylic acids added may also act as plasticizing agents.

Other substances may be added to the beet product prior to the casting or extrusion step to improve processing, to effect a desirable change in color, flavor or aroma, or to improve particular combustion characteristics such as ash content. Thus, plasticizers in addition to the above-mentioned acids may be incorporated into the slurry, such as tobacco extracts obtained by leaching tobacco parts with solvents, glycerine, or di or preferably triethylene glycol. These plasticizers may constitute from 1 to 10 parts by weight of plasticizer per 100 parts by weight of bee pulp.

Where flavor and aroma is to be adjusted, sugars, particularly crude brown sugar or invert sugar or its components may be added in an amount of from 1 to 50 parts by weight to 100 parts of beet pulp. These materials additionally act as plasticizers.

Special flavors may also be added and these may be present in an amount up to about 3 parts by weight to 100 parts by weight of beet pulp. Such flavorants might be cocoa shell, carbo bean, deer's tongue and many others commonly used in the toacco art. Other additives, such as colorants and nicotine may be incorporated in the final product in amounts depending on the effects desired.

After the substances described above are added for the desired or special characteristics to the treated beet slurry, the pH is again adjusted if necessary to pH %" AND THE SLURRY CAST OR EXTRUDED BY ANY OF THE PROCESSES KNOWN IN THE ART. Casting on a metal belt or the like for forming and drying is a preferred procedure but this is not the only way the product may be treated before final shredding as a smoking filler. Various other procedures, similar to those used in preparing reconstituted tobacco could be used for producing a sheet or extrusion in a variety of shapes.

It has been found that the beet pulp product processes well in casting to form a sheet. Sheet material has been produced with good tensile strength, for example, 0.7 to 1.0 kg./in. at 15 percent moisture and in shredded form has the filling power equal to that of conventional reconstituted tobaccos. The product may thus be used alone as a smoking filler or may be incorporated with tobacco in any desired amount or proportion.

The invention is further illustrated by the following examples:

EXAMPLE 1

Ingredients Extracted, dried sugar beet cossettes 55 g. Water 755 ml. H.sub.3 PO.sub.4 0.46 g. H.sub.2 SO.sub.4 1.22 g. HCl 0.58 g. NaOH 0.42 g. KOH 3.07 g. CaO, powder 3.19 g. MgO, powder 0.80 g. Invert sugar 24.4 g. Triethylene glycol (TEG) 13.2 g. Flavors 5.0 g. Nicotine 1.25 g.

The beet pulp was cooked in the solution of mineral acids in water for four hours at about 80.degree.C. and then the slurry was refined in a Waring Blender for one-half hour. The slurry was stirred while the additives were introduced in sequence: first the hydroxides in solution, then the powdered oxides. As the divalent metal cross-linked pectins were precipitated, the agitation was increased to disperse them. Next citric acid was added until the pH was approximately 5.7. Sugar, TEG, and flavors were added. A CHECK WAS MADE TO INSURE THAT THE PH had not risen above 6.0. Finally the nicotine was stirred in.

The slurry was cast on a moving steel belt at a thickness of 25 mils, dried and removed from the belt. The sheet processed well. Tensile strength at 15 percent moisture content was about 0.8 kg./in. width. When cut as filler, the product had fillinpower equivalent to that of conventional reconstituted product.

Cigarettes were made from a blend of 30 parts by weight of this product with 70 parts of a commercial all-leaf filler. Expert smokers judged this to be an acceptable filler in flavor and lack of harshness.

EXAMPLE 2

Ingredients Extracted, dried sugar beet cossettes 55.0 g. Water 750 ml. Hydrochloric acid (37% aqueous) 4 to 6 ml. Ca.sub.3 (PO.sub.4).sub.2 11.2 g. Invert sugar 26.4 g. Triethylene glycol (TEG) 13.2 g.

After the beet pulp was suspended in the water, the pH was adjusted to 2.5 to 3.0 and kept there during the cook by addition of HCl After a four hour cook, the slurry was refined by one-half hour treatment in a Waring Blender. The slurry was stirred in the blender while the tricalcium phosphate was added and agitation continued to ensure uniform dispersion of the solid phosphate. The sugar and TEG were added and the slurry was used to lay down 25 mil sheets on glass plates. These were dried and removed to be cut and used as filler. In this case, there would be only a small amount of cross-linking due to the reaction of the free acid groups naturally present in beet pectin. The film was not strong when wet. Though it was used satisfactorily for cigarettes made by hand, in commercial cigarette making processes, it would be likely to break up to short shreds or dust.

EXAMPLE 3

Ingredients Dried extracted sugar beet pulp 334.4 g. Water 11.4 liters Diammonium phosphate (DAP) 30.4 g. Invert sugar 228.0 g. Citric acid 79.0 g. Triethylene glycol 12.2 g. Potassium hydroxide 10.0 g. Calcium hydroxide 26.4 g.

All ingredients except the pulp and Ca(OH).sub.2, were dissolved in the water. The pulp was added in a Valley beater to the solution and beating was continued 2 1/2 hours. Then the powdered Ca(OH).sub.2 was added with beating. The final pH was 5.6. Sheet was cast on stainless steel plate at a casting blade setting of 50 mils, air dried overnight, doctored from the plate, conditioned at 60 percent, relative humidity, and shredded into cigarette filler.

Sheet prepared similarly from washed burley tobacco stems was used as control. Expert smokers found cigarettes made from the two materials generally equivalent, with the beet pulp product slightly but not significantly preferred.

EXAMPLE 4

Ingredients Exhausted sugar beet pulp 1360 g. tc 17 liters H.sub.3 PO.sub.4 10.5 g. H.sub.2 SO.sub.4 27.8 g. HCl 13.2 g. NaOH 9.5 g. KOH 69.5 g. Ca(OH).sub.2 96.0 g. Mg(OH).sub.2 26.1 g. Invert sugar 554 g. TEG 300 g. Dry flavors 113 g. Nicotine 38.4 g.

The acids and pulp were mixed with the water in a Cowles dissolver, cooked four hours at about 80.degree.C. The slurry was refined in a Sprout-Waldron 12 inch non-pressurized refiner for three passes. The Cowles dissolver was used to introduced the monovalent hydroxides, then the divalent hydroxides, followed by beating. Citric acid was added to bring pH to 5.7. The invert sugar, TEG and the dry flavors were added, then the pH was rechecked to make sure it was not over 6.0. Nicotine was finally added. The slurry was cast on a moving steel belt at 25 mils, dried, peeled off and used for filler.

Claims

The invention claimed is:

1. The process for preparing a smoking product from sugar beet pulp comprising the following sequence of steps:

a. cooking an aqueous slurry of extracted sugar beet pulp in comminuted form with a hydrolyzing agent to release beet pectins;

b. refinng the hydrolyzed product to shorten fibers and break up fiber bundles;

c. addinto the refined slurry components an alkaline earth metal cross-linking agent to cross-link the beet pectin molecules into a gel-like binding substance; and then

d. forming a dried product from the slurry components.

2. The process of claim 1 in which the hydrolyzed and refined product of step 9(b) is subjected to a demethylation step by reacting the released beet pectins with an alkaline demethylating agent.

3. The process of claim 2 in which the alkaline demethylating agent is added before the addition of the alkaline earth metal cross-linking agent.

4. The process of claim 2 in which the demethylating agent is added together with the alkaline earth metal cross-linking agent.

5. The process of claim 2 in which the demethylating agent is at least one of sodium and potassium hydroxide and the cross-linking agent is at least one of calcium and magnesium oxide or hydroxide.

6. A smoking product produced by the process comprising

a. cooking an aqueous slurry of extracted sugar beet pulp with a hydrolyzing agent to reduce beet pectins;

b. adding to the cooked slurry a polyvalent metal cross-linking agent to cross-link the sugar beet pectin molecules into a gel-like binding substance; and then

c. forming a dried product from the slurry components.

7. A product according to claim 6, wherein the cooked slurry of step (a) is comminuted to shorten fibers and break up fiber bundles.

8. A product according to claim 6, wherein the cooked slurry of step (a) IS SUBJECTED TO A DEMETHYLATION OR SAPONIFICATION STEP BY REACTING THE SUGAR BEET PECTINS WITH AN ALKALINE DEMETHYLATING OR SAPONIFICATING AGENT.

9. The product according to claim 8, wherein the cooked slurry of step (a) is comminuted to shorten fibers and break up fiber bundles prior to the addition of the demethylating or saponificating agent.

10. A product according to claim 6 wherein the cross-linkng agent is selected from the group consisting of cations of calcium and magnesium ions.

11. A product according to claim 8 wherein the cross-linking agent is selected from the group consisting of cations of calcium and magnesium ions.

12. A product according to claim 6 wherein tobacco is present in the dried product.

13. A product according to claim 8 wherein tobacco is present in the dried product.