US3782391A - {62 -methylvaleric acid alkyl esters as tobacco flavorants - Google Patents

Abstract

An article of manufacture comprising tobacco and a small but effective amount of a flavoring agent selected from the group consisting essentially of Cn-C10 alkyl esters and Beta phenethyl ester of Beta -methylvaleric acid. The esters have such volatility that the greater part of the ester is released into the smoke stream, as said ester without decomposition during smoking.

Description

Unite States Patent [1 1 Means et a1.

[SI-METHYLVALERIC ACID ALKYL ESTERS AS TOBACCO FLAVORANTS Inventors: Richard E. Means; Andrew G.

Kallianos; Kinwood P. Tenney, all of Durham, NC.

Assignee: Liggett & Meyers Incorporation,

New York, N.Y.

Filed: Mar. 24, 1971 Appl. No.: 127,792

US. Cl. 131/17 R, 131/144 Int. Cl A24b 15/04 Field of Search 131/2, 17, 140-144 References Cited UNITED STATES PATENTS 10/1956 Jones 131/17R Jan. 1, 1974 Primary Examiner-Melvin D. Rein Attorney-Kenyon & Kenyon Reilly Carr & Chapin ABSTRACT 5 Claims, No Drawings B-METHYLVALERIC ACllD ALKYL ESTERS AS TOBACCO FLAVORANTS DESCRIPTION OF INVENTION This invention relates to tobacco and more particularly to a tobacco composition including at least one agent which imparts improved flavor characteristics to the tobacco and the smoke thereof.

it has long been known in the tobacco art that domestic tobaccos such as burley, Maryland and bright leaf or Virginia are low in natural flavor compared to the so-called oriental or aromatic tobaccos which are imported from Turkey, Greece, and other countries. Those aromatic tobaccos contain natural materials in their composition which give those tobaccos characteristic aroma and flavor. In order to produce more flavorful tobacco products, it has long been the usual prac tice in the United States tobacco industry to either blend domestic and oriental tobaccos and/or add synthetic or natural additives to domestic tobacco blends. These techniques provide cigarettes and other tobacco products which possess desired flavor and aroma characteristics.

The present invention comprises a composition of tobacco and a flavoring agent or mixture of agents which said flavoring agent or mixture of agents impart to the tobacco and smoke thereof a fruity, apple-like aroma and a nut-like flavor.

Briefly, the present invention comprises tobacco to which has been added a small but effective amount of a compound or mixture of compounds selected from a group consisting of C -C B-methylvaleric acid esters. The generic chemical structure of the flavoring agent may be represented by the following structural formula:

wherein R is selected from the group consisting of C -C alkyl groups, such as, for example: methyl, ethyl, isopropyl, n-butyl, 3-methylamyl, n-decyl; or is B-phenethyl.

It has now been found that addition of these lower alkyl esters of fi-methylvaleric acid as described above imparts a characteristic apple-like aroma to a blend of tobaccos. Cigarettes prepared from tobaccos treated with these compounds release a smoke dominated by a fermented apple peel and English walnut-like aroma and flavor complex. These flavors and aromas provide a tobacco product which is desirable and unique as far as synthetic additives and flavoring agents to tobacco are concerned.

It has been found that the flavoring agent provides the best results when it is present in the proportion of at least parts of the agent for 1 million parts of tobacco (ppm). Proportions up to 200 ppm and greater can be used; at higher levels, however, certain of these particular agents impart, in addition to the above aroma and flavor complex, a characteristic chalky sourness. Although each ester may have an optimum proportion for most beneficial flavoring or aroma associated therewith, it has generally been found that the preferred range is between about 20 ppm and about 100 ppm of the agent.

The esters comprising the flavoring agents of this invention are generally prepared in accordance with known procedures. In the usual method, B-methylvaleric acid is heated for a period of time with the appropriate C C alkyl alcohol or B-phenethyl alcohol in the presence of an acid, such as sulfuric acid. The product is preferably purified prior to use.

The flavoring agent may be added to the tobacco by any of the well-known methods for incorporating addi tives into tobacco products. For example, an appropriate solution or admixture of the agent and a carrier may be sprayed, injected, dipped or otherwise applied in proper proportions to the tobacco.

Samples of cigarettes containing various esters as described herein were prepared and tested by an experienced taste panel for flavor and aroma in the tobacco and the smoke emanating therefrom. The following examples describe the preparation of the esters and the panel test results obtained when those cigarettes were compared to control cigarettes not having any of these flavoring agents combined with the tobaccos thereof.

EXAMPLE 1 Methyl B-Methylvalerate A solution of 9.2 g B-methylvaleric acid and 0.9 ml conc. sulfuric acid in 25 ml anhydrous methanol was refluxed on a steam bath for 4 hours. The excess methanol was removed on a rotary evaporator; the residue dissolved in ether; and, the ether solution washed with water, a saturated sodium bicarbonate solution, and a saturated sodium chloride solution. The ether solution was dried over sodium sulfate and concentrated on a rotary evaporator and the residue was distilled; b.p.: 48C/20-25 mm; A CCL: 5.75 p. (C=O); 8.49 p. (C-O); mass spectrum: M at m/e 130.

The product was evaluated organoleptically at 30 and 60 ppm levels on a commercial blend of tobaccos by spraying a solution of the compound thereon. At 30 ppm this compound gave a good balance and a light fruity flavor to the smoke of cigarettes manufactured from the treated tobacco. There were also less bitter and dirty notes than the control cigarette without the agent. At 60 ppm the sample cigarette produced a smoke having a light, green-floral, walnut note and a light, metallic-chalky, coating on the tonque.

EXAMPLE II Ethyl B-Methylvalerate A sample of 10 g of B-methylvaleric acid was converted to the ethyl ester by refluxing in 25 ml absolute ethanol containing 1.6 ml concentrated sulfuric acid. The cooled solution was poured onto ml cold water and the aqueous mixture was extracted with 50 ml ether. The ether layer was washed with saturated sodium bicarbonate solution and water, dried over sodium sulfate, and evaporated on a rotary evaporator. The residue required no further purification; k CCh: 5.76 p. (C=O); 8.46 p. (CO); mass spectrum: M at m/e 144.

The compound was evaluated organoleptically at 50, 100, and 200 ppm on a commercial blend of tobaccos. The smoke flavor and aroma were dominated by a fermented apple-peel and English walnut complex. Higher levels resulted in mouth irritations and sour notes.

EXAMPLE Ill isopropyl B-Methylvalerate A solution of 5 g B-methylvaleric acid, 0.8 ml conc. sulfuric acid, and l9 ml isopropyl alcohol in 50 ml benzene was refluxed with stirring for 6 hours. The benzene and excess isopropyl alcohol were removed on a rotary evaporator and the residue was dissolved in ether. The ether solution was washed with saturated sodium bicarbonate solution, water, and a saturated sodium chloride solution; dried over sodium sulfate; and, concentrated on a rotary evaporator to give a product which required no further purification; )t CCL: 5.80 p. (C=O); 8.45 p. (CO); mass spectrum: M at rn/e 158.

This product was flavor tested at 20 and 40 ppm on a commercial blend of tobaccos. At 20 ppm this com pound gave a more flavorful (fruity-type) note to the cigarette. At 40 ppm the sample cigarette had a low level nut-like note associated with burnt taste effects.

EXAMPLE lV n-Propyl ,B-Methylvalerate A solution of 5 g B-methylvaleric acid and 0.5 ml sulfuric acidin ml n-propyl alcohol was refluxed with stirring for 4.5 hours. The workup procedure was identical to that of Example Ill. The product has: k CCh: 5.77 p. (C=O); 8.48 p. (CO); mass spectrum: M at m/e 158.

Organoleptic evaluation was at 30 and 60 ppm on a commercial blend of tobaccos. At 30 ppm application the sample cigarette had a low level fruity-apple like note. At 60 ppm a sour fermented note was tied to the fruity note and the burnt was chemical-like. At 60 ppm the mouth effects were higher than the control cigarette, having a dirty, dusty, drying, coating complex.

EXAMPLE V n-Butyl B-Methylvalerate A solution of 10 g ,B-methylvaleric acid, 1.6 ml conc. sulfuric acid and 25 ml n-butyl alcohol in 50 ml dry benzene was refluxed with stirring on a Dean-Stark trap for 2 hours. Ether was added to the cooled solution which was washed with saturated sodium bicarbonate solution, water, and saturated sodium chloride solution; dried over sodium sulfate; and, evaporated. The product was purified by distillation; b.p.: 88-89C/- -25 mm; k CCl z 5.76 [L (C=O); 8.47 (CO); mass spectrum: M at m/e 172.

At ppm a low level apple note was detected in the smoke flavor of cigarettes manufactured from a commercial blend of tobaccos. A level of 50 ppm produced low walnut and apple tastes. The 100 and 200 ppm levels produced flavor similar to that noted at 25 and 50 ppm but with increased bitterness.

EXAMPLE VI lsoamyl B-Methylvalerate A solution of 5 g fl-m'ethylvaleric acid, 0.5 ml conc. sulfuric acid, and 20 ml isoamyl alcohol in 50 ml dry benzene was stirred and refluxed on a Dean-Stark trap for 7 hours. Workup procedure was indentical to that used for Example V. The product was purified by distillation; b.p.: 100C/20-25 mrn; A CCL: 5.76 p. (C=O); 8.46 p. (CO); mass spectrum: M at m/e 186.

The product was evaluated organoleptically at and 60 ppm on cigarettes manufactured from a commercial blend of tobaccos. At 30 ppm application the additive offered a low green fruit note which was smoother than the control. it imparted a bright tobacco-like flavor, and a dirty Turkish tobacco-like complex in the smoke flavor.

At 60 ppm application the additive caused the cigarette to be overdone flavor-wise.

EXAMPLE Vll n-Amyl B-Methylvalerate A sample of 5 g B-methylvaleric acid in 20 ml n-amyl alcohol, 0.5 ml. conc. sulfuric acid and 50 ml dry benzene was converted to n-amyl B-methylvalerate as in Example V. The product was distilled at l07l09C/- 20-25 mm; A CCh: 5.76 p. (C=O); 8.47 n (CO); mass spectrum: M* at m/e 186.

Organoleptic evaluation was performed at and 140 ppm on cigarettes manufactured from a commercial blend of tobaccos. At 70 ppm the sample cigarette was similar to the control but was slightly smoother. A low fruity-apple-like note was detectable. At 140 ppm application the sample cigarette was judged overdone in terms of flavor.

EXAMPLE VIII 3-Methylamyl B-Methylvalerate 3-Methylamyl B-methylvalerate was synthesized from 5 g B-methylvaleric acid, 4.4 g 3-methylamyl alcohol, and 0.5 ml conc. sulfuric acid in 50 ml dry benzene by the same procedure used in Example V. The product was purified by distillation at l l7l 19C/20-25 mm; A CCh: 5.79 p. (C=O); 8.48 p. (CO); mass spectrum: M at m/e 200.

Flavor evaluation was at 30 and 60 ppm on cigarettes manufactured from a commercial blend of tobaccos. At 30 ppm this additive caused the smoke flavor to be come smoother and slightly sweeter than the control cigarette. The flavor was well blended with no distinct flavor notes evidenced. At 60 ppm the additive caused the sample cigarette to have a slight raw impression associated with the tobacco fragrance.

EXAMPLE IX n-Decyl B-Methylvalerate A sample of 5 g B-methylvaleric acid, 6.8 g n-decyl alcohol, and 0.5 ml conc. sulfuric acid in 50 ml dry benzene were refluxed with stirring on a Dean-Stark trap for 6 hours. Saturated sodium bicarbonate solution was added to the cooled reaction solution and the entire mixture shaken in a separatory funnel. The resulting emulsion was separated on a centrifuge. The organic layer was removed with a pipet; dried over sodium sulfate; and, concentrated on a rotary evaporator. The product was distilled at ll3-l l3.5C/l2 mrn; X CCL: 5.77 p. (C=O); 8.47 p. (CO); mass spectrum: M* at m/e 256.

The product was organoleptically evaluated at 40 and ppm on cigarettes manufactured from a commercial blend of tobaccos. At the 40 ppm level this ad ditive provided a slightly smoother smoke than the control cigarette. A light green fruity-sour-fermenty-sweet complex dominated the smoke flavor. The sample had a low tobacco fragrance. At 80 ppm the sample cigarette had a dirty-raw vegetable-like note which was reminiscent of celery or potato. The peppery stimulation was higher than the control.

EXAMPLE x B-Phenethyl B-Methylvalerate A solution of 3.1 g (0.0259 mole) B-phenethyl alcohol, 3 g (0.0259 mole) B-methylvaleric acid and 0.2 ml conc. sulfuric acid in 60 in] dry benzene was refluxed with stirring on a Dean-Stark trap for 4.25 hours. After cooling, the reaction mixture was washed sequentially with saturated sodium bicarbonate solution, water, and

saturated sodium chloride solution. The organic layer was then removed, dried over anhydrous sodium sulfate and, after filtration, the solvent was removed on a rotary evaporator. The purity of the product was determined by gas chromatography. Infrared: A CCh: 5.76 p. (C=O); 8.50 p. (C-O); mass spectrum: M at m/e 220.

The product was evaluated organoleptically on cigarettes manufactured from a commercial blend of tobaccos. At 50 ppm the additive produced a smoke that was judged as more flavorful having a Valerian-fruity note with some residual coating. The additive exhibits blending properties and its use in cigarettes results in improved smoking quality of the product.

The flavoring agent of this invention may be blended with the tobacco in any convenient manner. For example, it can be dissolved in ethanol or other suitable solvents, or admixed with a carrier such as casing solution to form a suspension or dispersion, and the resulting combination sprayed, dipped or otherwise applied on the tobacco. Alternatively, the agent or combination of agents can be blended with other tobacco additives and then mixed into the tobacco. Thus it can be incorporated into blends normally employed to produce reconstituted tobacco sheet.

In addition to being useful in the manufacture of cigarette tobacco, the additives are also suitable for use in connection with the manufacture of pipe tobacco or other tobacco products.

It will be appreciated that while several embodiments of this invention are shown above, the invention is not to be limited thereto, since many modifications will be obvious to those skilled in the art and that the present invention is defined by the appended claims.

What is claimed is:

1. Tobacco smoking articles comprising: tobacco; and a small but effective amount of flavoring agent wherein the proportion of said flavoring agent in said article is in the range of between about 20 to parts by weight for 1 million parts by weight of said tobacco, said agent comprising at least one ester selected from the group consisting of C -C alkyl esters of B-methylvaleric acid, said esters having a volatility such that the greater part of said ester is released as said ester without decomposition thereof into the smoke of said smoking article which is drawn through said smoking article to the smoker.

2. The tobacco smoking articles of claim 1 wherein said articles are cigarettes.

3. The article of claim 1 wherein said ester is ethyl B-methylvalerate.

4. The article of claim 1 wherein said ester is isoamyl B-methylvalerate.

5. The article of claim 1 wherein said ester is 3- methylamyl B-rnethylvalerate.

Claims (4)

1. 2. The tobacco smoking articles of claim 1 wherein said articles are cigarettes.
2. 3. The article of claim 1 wherein said ester is ethyl Beta -methylvalerate.
3. 4. The article of claim 1 wherein said ester is isoamyl Beta -methylvalerate.
4. 5. The article of claim 1 wherein said ester is 3-methylamyl Beta -methylvalerate.