US2766146A - Tobacco - Google Patents

Description

TOBACCO No Drawing. Application July 26, 1954, Serial No. 445L892 9 Claims. (Cl. 13117) N. (3., assignor Winston-Salem,

This invention relates to tobacco and has for an object the provision of a smoking tobacco product having improved aroma and flavor characteristics which become apparent during smoking.

Smoking tobacco as now prepared for use in cigarettes comprises essentially a blended mixture of various types of tobaccos which are desired to produce a characteristic flavor and aroma when the tobacco is smoked. Present day cigarette tobaccos normally comprise blends of 1) heat-cured tobaccos, which are sometimes known as flue-cured, bright leaf or Virginia tobaccos, (2) air-cured tobaccos, which are sometimes known as burley or Kentucky and Maryland tobaccos, and (3) sun-cured tobaccos, which are known as Turkish or Oriental tobaccos. The relative proportions of these various types blended to produce a desired cigarette tobacco mixture depend in a large measure upon the characteristic flavor or aroma that is desired to be achieved when the tobacco is smoked. Also it is common practice to add various substances, such as flavoring materials and humectants, in order to provide other desired properties.

A further object of this invention is to provide a smoking tobacco which when smoked will have improved or enhanced flavor and odor characteristics which will be pleasing to the smoker.

A further object of this invention is the provision of a smoking tobacco having added thereto a compound or compounds which, when the tobacco is smoked, will liberate one or more organic acids imparting a selected and desired flavor and aroma to the smoke.

A still further object of this invention is the provision of a tobacco product having added thereto a substantially nonvolatile substance which in itself does not substantially change the flavor or aroma of the tobacco but which when burned on the tobacco will release to the smoke certain desired flavoror aroma-producing acids.

A still further object of this invention is the provision of a tobacco having added thereto an organic compound which, when the tobacco is smoked or burned, will liberate several types of flavoring acids whereby the desired improvement in the flavor and aroma of the smoke may be achieved.

A still further object of this invention is the provision of additives for tobacco which may be easily and simply prepared and which may be incorporated into the tobacco at any stage during the processing thereof.

A further object of this invention is the provision of a tobacco containing an additive which is a derivative of certain sugars, said derivative being one which will release a flavor-producing acid when the tobacco is smoked.

Further and additional objects will appear from the following description and the appended claims.

In the copending application of Samuel OBrien Jones, Serial No. 445,891, filed July 26, 1954, it is disclosed that certain esters of flavor-producing acids when added to tobacco will, when smoked or burned with the tobacco, re lease the acid or acids, which latter impart a desired chartates Patent acteristic odor and/or flavor to the smoke, thereby contributing to the enjoyment of the smoker.

In accordance with the broad aspects of this invention, a smoking tobacco composition is provided which contains as an additive a small amount of an ester of a polyhydroxy compound related to the carbohydrates and selected from the group consisting of the mono and poly esters of rhamnose, galactose and sorbose, which ester, when smoked or burned with the tobacco, will release one or more organic flavoring acids preferably having from 3 to 8 carbon atoms. These acids, when present in the smoke in suitable concentrations, will impart characteristic and desirable flavor and aroma to the tobacco smoke, thus contributing to the enjoyment of the smoker. These additives are substantially non-volatile under ordinary tobacco storage conditions and will remain dispersed throughout the tobacco untilsuch time as it is smoked and they are sufliciently nonvolatile so that they will remain in the burning area of the tobacco to permit the acid release to occur. Obviously the additive should not volatilize much ahead of the burning Zone or the desired acid release may not occur. The additives herein disclosed are relatively stable under the usual tobacco storage conditions; consequently, the principal release of flavoring acid or acids does not occur until the tobacco is smoked.

The flavor-producing acids which are released by the esters in accordance with this invention are preferably those flavoring acids which will volatilize and will be carried by the smoke, such acids usually being the organic carboxylic acids having 3, 4, 5, 6, 7 or 8 carbon atoms, herein collectively referred to as those having from 3 to 8 carbon atoms. Representative acids are the saturated aliphatic fatty acids, such as propionic, n-butyric, isobutyn'c, n-valeric, isovaleric, 2-methylbutyric, n-caproic, 4-methylvaleric, 3-methylvaleric, 2,2-dimethylbutyric, 2- methylisovaleric, straight or branched chain heptoic, or straight or branched chain caprylic acids; the unsaturated aliphatic fatty acids, such as acrylic, crotonic, vinylacetic, 4-methyl-4-hexenoic and S-methylsorbic acids; the cycloalkane or cycloalkene aliphatic acids, such as cyclopentanecarboxylic, cyclohexanecarboxylic, cyclopentaneacetic or cyclohexaneacetic acids or the corresponding unsaturated cycloalkenes; the aromatic carboxylic acids, such as benzoic or toluic acids; and phenylacetic acid. Also the volatile derivatives of such acids, such as hydroxy acids or keto acids may be the acid compound released to impart the desired odor or flavor to the smoke. It is preferred that the flavoring acid be an aliphatic or alicyclic saturated monocarboxylic acid of the fatty acid series having 4, 5 or 6 carbon atoms, herein collectively referred to as those having from 4 to 6 carbon atoms.

It will be apparent that the ester additive may be selected or prepared in such a manner that any one of the foregoing acids will be released during smoking. Also a single additive or mixture of additives may be selected and added to the tobacco so that a plurality of desired flavoring acids may be simultaneously liberated if desired, thus effecting a blend of the various types of aromas which has the characteristics of the several flavoring acids. Also, if desired, the several hydroxyl groups in the polyhydroxy compound may be esterified with one or more different flavoring acids or less than all of the hydroxyl groups may be esterified to produce the additive used in accordance with this invention. The specific flavor-producing acid or acids that are combined with the hydroxy compound to form the ester will depend upon the flavor and aroma desired in the tobacco smoke. As indicated above, the particular acid selected for the preparation of the ester is of consequence only in so far as the particular flavor contributed by that particular acid is important. Any of the flavor-producing acids may be utilized and, as previously indicated, they gen- The additives contemplated -by-this invention maybeincorpora-ted into-the tobacco in any desired manner. For example, solutions ofthe additive in-a suitable solvent, such as-alcohol ethyl ether, acetone or the like,-may be applied to the tobacco as by spraying or otherwise, whereafter the solventis driven ofias a vapor leaving the additive-thoroughly incorporated with the tobacco. The additive may also be uniformly dispersed in water and ap: plied in a like manner if desired: The incorporation of the additive may take placeat anytime prior to the .final packagingof the tobacco product; In-the case of cigarette tobacco, it may be incorporated before or after blending of the various tobaccos if, in fact, blended tobaccois employed, and thegadditives may be applied.

to one or all of the blend constituents. Under certain circumstances the additive may be incorporated into the tobacco before agingand curing, however, this would not ordinarily be done if the additive has a tendency to decompose during the aging and curingrprocess. In the case of cigarettes the additive in some instances might be applied to the paper instead of to the tobacco.

The amount of additive in the final product contemplated by this invention is quite small but willvary widely with the particular additive employed and the amount of acid released upon burning or theflavor or aroma desired in the smoke. Thus an additive that releases only a comparatively small fraction of its total available flavoring acid on burning will be required in higher concentrations than those additives which are more eificient with respect tothe amount of flavoring acidreleased. Also it is well known, that someof the aliphatic fatty acids having 4 to 6 carbon atoms havea disagreeable odor per se when vapors of these acids are smelled in certain concentrations. However, in very. low concentna-tions they provide in the tobacco smoke a desira'ble flavorand.

aroma, and the amount of additive in the tobacco should be such as u-otto exceed the amount which,-when the tobacco issmoked, will release desirable quantities of the acid. This amount in many cases will be determined byactual experimentation. Generally speaking, however,

desirable flavor and aroma are producedif theadditives are incorporated into the final tobacco product in amounts between about 0.01 and 1.0 percent by weigh-t(dry basis).

lnevaluating the various esters contemplated within the scope. of this invention, the ester being tested was dissolved in a volatilesolvent, such as acetone, alcohol or ether, using 2 to 40 milligrams of ester per milliliter of solvent. was then distributed througha one-inch portion (which was to be burned) of a cigarette by means or" a A milliliter hypodermic syringe. The volatile solvent was then blown out of the cigarette with a stream of compressed air, leaving the additive dispersed in the cigarette. The tobacco in the cigarette so treated was evaluated by organoleptic testing. the cigarette and examining the smoke by sensory methods. in each test special efforts were made to determine whether any acid odor was present in the smoke. This One-fourth milliliter of the resulting solution- This was carried out by smoking included a careful sensory study of both the main stream and the side stream. if the acid odor was detected in either the side stream or the main stream, it was coneluded that the ester released the acid during the smoking of the treated tobacco or cigarette.

In the foregoing, reference has been made to a general class of compounds which are useful as additives for tobacco in accordance with this invention. Certain of the specific compounds in this class are new and certain of them are not available commercially. Accordingly, severe. examples will be presented in the, following disclosing methods of preparing representative compounds at are useful asadditives in accordance with this inven- A tion. In each case the compounds which were prepared by 'the specific procedures given in the exampl'esto'fol low were tested by the method previously mentioned and each was found to release flavoring acid when smoked with tobacco. It will be understood that in the following, examples are given of preparing esters which will, upon burning or smoking oft-he tobacco treated therewith, liberateonly one of the flavor-producing acids contemplated by this invention. However, it will 'be apparent to one-skilled in theart how-other esters releasing other particular flavoring acids may be prepared. For example, iu the following where there are given examples of processesof{preparingesters of isovaleric acid and 4-methylvaleric acid, it will be understood that essentially the same or similar. means kuown tochemists could be employed for preparing the esters of other flavoring acids of the character hereinabove specified and that all such, esters are contemplated as additives within the scope of this invention.

Galactose pentaisovalerate Ten grams (0.056 mole) of anhydrous ga1actose,'8 grams (0.058 'mole) of potassium isovalerate and 93 gnams (0.5'mole) of. isovaleric anhydride were heated at 80400". C. with mechanicalstirring for 6 hours. cooling, one-sixth of the mixture was poured into ice water and extracted with ether. The ether layer was concentrated and then was partitioned .between six 40- milliliter layers each of hexane and %v methanol.

Concentration of the combined upper layers yielded 4.04.

grams of 'galactose pentaisovalerate (0.0067 mole, 7.1% of theory); light yellow oil.- n D 1.4493.

Rhamnose triisovalerate Sol-base pentakz's(4-methylvalerate) =Sorbose was ground to pass a meshiscreenand 11.6 grams (0.0645 mole) were mixed with 64.7"grams (0.82 mole) of pyridine and;126.5 grams (0:59'mole)"of 4-methylvaleric' anhydride. The mixture was stirred mechanically at room temperatureun-til all :the sugar had dissolved (overnight) and was thenLal-loWed to stand for 3 more days. The reaction mixture was then partitioned, using four l-liter layers eachof hexane and 90% meth anol. The lower layers, containingpyridine, 4'methyl valeric acid, and incompletely acylated sorbosewere dis-c carded. Thecombined upper layers were concentrated and yielded 41.5 grams of oil. This was dissolvedin 100 milliliters of castor oil (to serve as a carrier onthe still) and was subjected to molecular distillation on a laboratory still. The sorbose 4-methylvalerate. distilled at -l50 C. at 7 to 20 microns; yie1d-.22.7 grams- (0.035 mole, 53% of theory), yellow oil with a faint odor, shown to be essentiallya pure compound by the Craig distribution technique: 113 B 1.4565.

Sorbose tetraand pentaisovalerate These esters were prepared by the preceding. method, using 55 grams (0.306'mole) of sorbose, '304' grams'(3'.8 moles) of pyridine, and 515 grams (2 .77 moles) of isovaleric anhydride. After-the=reaction-,-most of the excessreagents -were distilled outof the mixture by heating-it to 505-60 C: under vacuum Theresidual oil (201 grams) was placed in. a DPI molecular still. andJ117 After grams of distillate were collected at l20-l50 C. at to 20 microns. This was partitioned between seven 800- milliliter layers of hexane and seven 800-milliliter layers of 90% methanol. Concentration of the combined upper layers yielded 71 grams (0.118 mole, 38.6% of theory) of sorbose pentaisolvalerate; lemon-colored oil. Concentration of the combined lower layers yielded 44 grams (0.085 mole, 27.8% of theory) of sorbose tetraisolvalerate; amber-colored oil. Both products were shown to be essentially pure by the Craig distribution technique.

It will be understood that the foregoing specific examples are only representative of the large number of esters of rhamnose, galactose and sorbose that may be used to release acid on smoking of a tobaccotreated therewith. It will also be understood that these compounds may be prepared by other methods that are well known to the art generally. The specific examples given are believed to be adequate to show the manner in which a large number of esters of the various hydroxy compounds and the several flavoring acids may be readily prepared.

A specific example showing a method for applying the additive to cigarette tobacco is as follows: Twenty millograms of sorbose pentakis(4-methylvalerate) were dissolved in milliliters of acetone and were injected into test cigarettes as follows. One-quarter milliliter of the solution was distributed through the end portion of a flue-cured cigarette by means of a /4 milliliter hypodermic syringe, and the volatile solvent was blown out of the cigarette by means of a stream of compressed air, leaving the fiavorant dispersed in the tobacco. Several cigarettes were prepared in this manner and examined by a panel of smokers, care being taken to light the treated end of each cigarette. 4-methylvaleric acid was detected in the mainstream and sidestream smoke from the cigarettes.

Studies have been made in order to determine the extent to which various compounds will actually release acid when smoked with tobacco. As pointed out in the abovementioned copending Jones application, an arbitrary scale has been set up for comparing or evaluating the various additives that may be incorporated into tobacco. The additives which liberate the largest amount of acid on an organoleptic test basis during smoking have been arbitrarily assigned a rating of 10. The additives at the bottom of the scale liberating detectable but small quantities of acid on an organoleptic test basis have been assigned a rating of 1. Using this arbitrary scale and evaluating the various additives by a test panel of a number of smokers, the following ratings were arrived at for certain of the compounds contemplated within the scope of this invention; rhamnose triisovalerate has a 6 rating, galactose pentaisovalerate has a 7 rating, sorbose pentakis(4-methylvalerate) and sorbose pentaisolvalerate each have an 8 rating and sorbose tetraisovalerate has a 9 rating.

While the rating given a particular compound is indicative of acid release, it is not necessarily conclusive in evaluating that compound for commercial use as a tobacco additive. For example, some compounds having a high rating may have a tendency to be unstable under tobacco storage conditions, thereby prematurely releasing the acid, it being understood that it is generally desirable for the acid not to be released prior to smoking. Also it is pointed out that the carbohydrates from which the esters are prepared in accordance with this invention are naturally-occurring and are similar to those occurring in tobacco, and the presence of such carbohydrates or of their derivatives as a residue after the acid has been released does not introduce any foreign type of constituent into the tobacco during the smoking procedure.

Also in accordance with this invention, it may in certain instances be desirable to employ an ester of the polyhydroxy compound wherein less than all of the hydroxyl groups are esterified with the flavoring acid. However, at least theoretically, such compounds are capable of releasing fewer molecules of flavoring acid per molecule of the ester. Thus, on a weight for weight basis, the polyesters may be more effective than the corresponding monoesters. Generally, however, the degree of acid release in each instance should be tested by actual trial since the degree of acid release does not always appear to be directly proportional to the number of esterified groups in the hydroxy compound.

It will be understood that compositions have been prepared in accordance with this invention which have improved or enhanced aroma and flavor to give increased pleasure during smoking. Infinite variations with respect to the kinds and amounts of flavor-producing acids are possible and may be readily controlled. Such flavor-producing esters may be particularly useful with tobaccos which are ordinarily low in the type of flavor imparted by the flavoring acids. While the invention has been specifically described with reference to cigarettes, it will be apparent that it has application in the manufacture of other smoking tobaccos such as used for hand-rolled cigarettes, pipes and cigars.

While several particular embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

I claim:

1. An article of manufacture comprising tobacco and a derivative of a polyhydroxy compound selected from the group consisting of rhamnose, galactose and sorbose, said derivative upon smoking with tobacco being capable of releasing a volatile carboxylic organic flavoring acid.

2. An article of manufacture comprising tobacco and an ester of a volatile carboxylic organic acid and a polyhydroxy compound selected from the group consisting of rhamnose, galactose and sorbose.

3. A smoking tobacco having added thereto a small amount of an ester of a volatile organic acid having from 3 to 8 carbon atoms and a polyhydroxy compound selected from the group consisting of rhamnose, galacrose and sorbose.

4. A smoking tobacco having added thereto a small amount of an ester of a volatile monocarboxylic organic acid having from 3 to 8 carbon atoms and a polyhydroxy compound selected from the group consisting of rhamnose, galactose and sorbose.

5. A smoking tobacco having added thereto between about 1.0 and about 0.01 per cent by weight (dry basis) of a nonvolatile ester of a monocarboxylic organic acid having from 4 to 6 carbon atoms and a polyhydroxy compound selected from the group consisting of rhamnose, galactose and sorbose.

6. The tobacco recited in claim 5 wherein said compound is rhamnose.

7. The tobacco recited in claim 5 wherein said compound is galactose.

8. The tobacco recited in claim 5 wherein said compound is sorbose.

9. A smoking tobacco having added thereto between about 1.0 and about 0.01 percent by weight (dry basis) of an ester of a volatile monocarboxylic organic acid having from 3 to 8 carbon atoms and a polyhydroxy compound selected from the group consisting of rhamnose, galactose and sorbose.

OTHER REFERENCES The Dispensatory of the U. 3., published 1947, by J. B. Lippincott Co., Philadelphia, Pa, page 1564.

Claims (1)

1. AN ARTICLE MANUFACTURE COMPRISING TOBACCO AND A DERIVATIVE OF A POLYHYDROXY COMPOUND SELECTED FROM THE GROUP CONSISTING OF RHAMNOSE, GALACTOSE AND SORBOSE, AND DERIVATIVE UPON SMOKING WITH TOBACCO BEING CAPABLE OF RELEASING A VOLATILE CARBOXYLIC ORGANIC FLAVORING ACID.