EP0235539B1 - Process for flavouring tabacco - Google Patents

Description

According to current practice, the tobacco industry uses the use of different flavoring substances in order to improve the organoleptic qualities of the different kinds of products of varied plant origin that it has to process.

Various flavoring techniques have been proposed in the past. However, the industry almost exclusively uses two traditional techniques: soaking the tobacco in a suitable solution, usually an aqueous solution, of the flavoring substance or spraying this solution on the tobacco itself.

The main disadvantage of these techniques is that the active aromatic components for the most part have an appreciable vapor pressure already at room temperature and, therefore, they evaporate and escape more or less quickly from the surface of the treated product.

To overcome this disadvantage, various encapsulation techniques have been proposed. US Pat. No. 3,550,598 describes a process which consists in spraying a suspension of water-soluble capsules containing the flavoring substance on the tobacco product to be flavored. Such a process has been applied in particular to the manufacture of reconstituted tobacco leaves using less noble cuts, powders or ribs, originating from the treatment of the leaves.

US Pat. No. 3,623,489 describes a process for the flavoring of tobacco which consists in adhering to tobacco cups or reconstituted leaves of microcapsules containing a volatile flavoring substance. Microcapsules have the property of bursting under the effect of heat, as it is released, for example when lighting or smoking a cigarette, to release the active volatile components of the aroma, generally of eugenol. The aforementioned US patent suggests that microcapsules can be obtained by any ordinary encapsulation method.

Other tobacco flavoring techniques have been suggested but have so far met with no major interest. Among these, mention may be made of the addition of flavor to a polymeric element intended to be incorporated into a cigarette filter (US patent 3,603,319) or the use of a cationic or anionic exchange resin which can be combined with certain molecules. basic or acidic flavoring agent (US Patent 3,280,823).

The prior art is rich in specific examples concerning the flavoring of food by microencapsulation. Among the processes recently made public, mention should be made of those described in European patent application 11324, US patent 4,339,422 and European patent 70719. These documents describe processes for the preparation of microcapsules by methods using the technique known as of the fluidized bed. More particularly, European patent 70719 describes a process for encapsulating volatile liquids, which process consists in spraying a suspension containing the volatile liquid and a solution of an appropriate support on solid particles, powders or scales, stirred in a fluidized bed mixer. Capsules containing the active volatile liquid are thus formed, which capsules can then be used for flavoring consumer products according to one of the known methods.

We have now discovered that it is possible to carry out the direct flavoring of tobacco, in the form of leaves, powders, particles or film, by a simple process which consists in bringing into contact an active volatile flavoring substance immiscible with l water with tobacco leaves or particles, contact being obtained by direct spraying on their exposed surface with an emulsion obtained by mixing the flavoring substance with an aqueous solution of a water-soluble support in the presence of an emulsifying agent.

The volatile flavoring substance is first retained on the surface of the tobacco leaves or particles by adhesion of the emulsion due to the binding effect exerted by the support substance. Under the effect of the ensuing drying, which is carried out by simple gradual exposure of the tobacco thus treated to the air or by the use of a heat source, if necessary by applying a slight suction or ventilation , the flavoring substance is retained in the form of small droplets coated with a water-soluble protective layer constituted by the support which is now dry.

This is a simple process which does not require the use of any particular apparatus, such as an atomizer or a fluidized bed mixer. The operation also takes place at room temperature, which results in energy savings compared to the methods mentioned. In most cases, it is not even necessary to dry the tobacco, the amount of water used for the preparation of the emulsion being absorbed entirely by the tobacco in order to maintain it at the required humidity level.

As water-soluble support, polyvinyl acetate (PVA), polyvinyl alcohol, dextrins (natural or modified), starch (natural or modified), vegetable gums, proteins (natural or alginates, carrageenans, pectins, xanthans or cellulose derivatives such as, for example, carboxymethylcellulose, methylcellulose, hydroxymethylcellulose. These water-soluble supports can be used separately or as a mixture. Preferably, gum arabic, shellac, maltodextrins, starch or partially hydrolysed proteins are used.

As emulsifying agent, mono- or diglycerides of fatty acids, esters of fatty acids with sorbitol or saccharides or esters of tartaric, citric, ascorbic or lactic acid can be used.

The process of the invention is carried out by spraying an emulsion and for this purpose a spray nozzle is used, for example with compressed air. It is of course possible to vary the pressure as a function of the viscosity of the emulsion, of the desired flow rate and of the product which it is desired to flavor. A pressure between 2 and 10 bar, preferably 3 to 5 bar, seems to be perfectly suited to the different cases examined.

According to a preferred embodiment, a nozzle of the Venturi type with compressed air at 4 bar is used, with an air nozzle with a diameter of 4 to 8 mm, a liquid suction nozzle of 0.6- 0.9 mm and an emulsion flow rate of 10 to 40 g / minute.

The application of the emulsion to the product to be treated can be done by placing the product on a flat surface, for example, by spreading it on a rolling belt or in a rotary drum, which makes it possible to obtain a very coating. homogeneous tobacco.

As indicated above, the water brought by the spray of the emulsion on the tobacco is absorbed or evaporates quickly at room temperature, which makes drying unnecessary. If the emulsion however were to add to tobacco quantities of water greater than 10-15%, drying in an oven of treated tobacco at around 40 ° C for 10 to 20 minutes may be necessary.

• a. de 0,5% à 20% pour la substance aromatisante volatile active,
• b. de 5% à 30% pour le support hydrosoluble,
• c. de 0,1% à 10% pour l'agent émulsifiant, et
• d. pour le restant d'eau.

The respective weight proportions of the different ingredients of the emulsion can vary within a fairly wide range of values. Preferably, they are

• at. from 0.5% to 20% for the active volatile flavoring substance,
• b. from 5% to 30% for the water-soluble support,
• vs. from 0.1% to 10% for the emulsifying agent, and
• d. for the rest of the water.

The process of the invention has certain advantages over known methods of flavoring tobacco.

It is indeed a "direct" method which does not call upon the techniques of indirect aroma encapsulation known in the art. The process is therefore more economical. Compared to the traditional methods practiced in the tobacco industry, such as the spraying of the aroma in the form of an alcoholic solution, the process of the invention proves to be more effective and more reliable. The dispersion of the volatile constituents of the aroma in the surrounding atmosphere during the spraying operation is less, which results on the one hand in a less loss of the aroma and on the other hand, a more balanced aromatization, the ratio respective of the different constituents of the aroma remaining practically constant throughout the operation. Finally, the tobacco thus flavored retains the organoleptic properties acquired for a long time without denaturing, the aroma being protected from external influences and agents (such as evaporation or oxidation) which could modify its own character.

The process of the invention can be applied just as well to the flavoring of tobacco of natural origin as to that of artificial tobacco. The spraying of the emulsion can take place during any phase of the tobacco treatment, either on the leaves or on sections.

As active flavoring substance, the flavoring compositions generally used can be used to impart, improve or modify the taste and aroma of tobacco. If necessary, it is of course possible to use specific aromatic substances isolated, such as menthol or eugenol. Among the useful volatile substances which can be used for this purpose, mention should be made of those described in patent FR 2,175,236. Their concentrations in the emulsion depend on the nature of the product to be treated, as well as on the particular aromatic effect that is sought. Concentrations of the order of 10 to 100-200 ppm (parts per million) by weight, based on the weight of flavored tobacco, can generally be used in most practical cases.

The invention will be illustrated in more detail but not limited to by the examples which follow.

Example 1

A flavoring composition of tobacco type (origin: Firmenich SA, Geneva: Tobacco 52.644) was incorporated at a rate of 1% by weight in an emulsion obtained by mixing the following ingredients (parts by weight): Malto-dextrin ¹⁾ (Maltrin-Glucidex, registered trademarks) 225 Manucol ²⁾ LF 5 Demineralized Water 770 Total 1000 1) a 10:90 mixture of maltodextrins (origin: Roquette Frères, Beinheim, France and Grain Processing Corporation, Muscatine, Iowa USA) 2) sodium alginate (origin: Alginate Industries Ltd., Great Britain).
The viscosity of this mixture is 72 cps.

100 grams of the aromatic emulsion thus obtained was dispersed by spraying using a Venturi nozzle on 1000 grams of cut tobacco ("American blend" type mixture). The flavored tobacco was then left to rest for 8 weeks, then it was used for the manufacture of cigarettes (test), the smoke of which was subjected to evaluation by a group of flavor experts. By comparison with the flavor of cigarettes flavored with the same flavoring composition by spraying with an alcoholic solution thereof (control) (100 g of 1% flavor solution in ethyl alcohol to 95% on 1000 grams of tobacco), it was observed that the "test" cigarettes developed a more marked and more harmonious aroma; they also developed indirect smoke (side stream) with a more sustained aroma.

Example 2

A flavoring composition of Virginia tabac type (origin: Firmenich SA, Geneva: Tabac 53.476) was incorporated at a rate of 0.5% by weight into the emulsion described in Example 1.

100 grams of the aromatic emulsion obtained was dispersed by spraying according to the method described in the previous example. The manufacture of "test" and "control" cigarettes, as well as the evaluation of their smoke, as indicated in said example.

The panel of experts was able to determine that the aroma developed by the "test" cigarettes had a richer note, while the acrid and irritant character specific to tobacco was reduced.

Example 3

A flavoring composition of the fruity type for tobacco (origin: Firmenich SA, Geneva: Tobacco 53.911) particularly suitable for flavoring tobacco (mixture of "flue-" and "air-cured" type tobacco with oriental tobacco) manufacture of kreteks (Indonesian type cigarettes) was incorporated at a rate of 1% by weight in the emulsion described in Example 1. The manufacture of “test” and “control” cigarettes as well as the evaluation of their smoke been performed as described above.

The test cigarettes developed a marked fruity character of ripe banana, with a light hint of dry fruit.

Example 4

The flavoring composition used in the previous example (Tabac 53.911, Firmenich SA) was incorporated at a rate of 1% by weight into the emulsion obtained by mixing the following ingredients (parts by weight):

"Test" and "control" cigarettes were then prepared as shown in Example 1. The evaluation by an expert group indicated that the smoke from the "test" cigarettes had a dry fruit character. and a slightly caramel note.

Example 5

The flavoring composition used in Example 3 (Tabac 53.911, Firmenich SA) was incorporated at a rate of 1% by weight in the emulsion obtained by mixing the following ingredients (parts by weight): Gum arabic 12 Malto-dextrin ¹⁾ (Maltrin-Glucidex, registered trademarks) 100 Manucol ²⁾ LF 2 Capsul ³⁾ 100 Arlacel ⁴⁾ 20 50 Hydrokollan ⁵⁾ PP4 50 Demineralized Water 686 Total 1000 1), 2) and 5) see Example 4 3) Modified corn starch (origin: National Starch and Chemical Corp., Bridgewater NJ, USA) 4) Sorbitol Laurate (origin: Atlas Chemical Industries NV, Everberg, Belgium).

Following the method described in Example 1, "test" and "control" cigarettes were prepared which were then subjected to evaluation (see previous examples). The expert group reported that smoke from "test" cigarettes had a dry fruit character and a typical aroma of ripe banana. The aroma developed by the "control" cigarettes, flavored with an alcoholic solution of the aroma in 95% alcohol, had on the other hand a slightly fatty, buttered and caramel character. The smoke developed by the "test" cigarettes was also less irritating thanks to its more fruity base note.

Example 6

A flavoring composition for “kretek” type cigarettes, consisting essentially of eugenol, was added, at a rate of 8% by weight, to an emulsion prepared according to the method indicated in Example 5. the flavoring of a tobacco mixture, as indicated in Example 1, and then conducts the organoleptic evaluation on the cigarettes obtained by comparison with “control” cigarettes flavored by spraying on the same type of tobacco of a alcoholic solution (95% ethyl alcohol) with the same aroma.

The "test" cigarettes developed a smoke whose aroma was more complete while having a better power of diffusion.

Organoleptic evaluation repeated after 20 weeks did not indicate any significant differences in taste.

Example 7

A 20% by weight solution of menthol in a 1: 1 mixture of ethanol / propylene glycol was incorporated into the emulsion described in Example 5 in an amount of 25 parts of menthol solution per 100 parts of emulsion. Following the method described in Example 1, an American blend of tobacco was then flavored, using 100 g of flavoring emulsion per 1 kg of tobacco.

The flavored tobacco was then left to stand for 8 weeks, then it was used to manufacture "test" cigarettes, the smoke of which was subjected to organoleptic evaluation by comparison with that developed by "control" cigarettes obtained by flavoring. using an alcoholic solution of the same aroma in 95% alcohol.

The aroma of "test" cigarettes was found to be more marked than that of "control" cigarettes.

An organoleptic evaluation was repeated after 20 weeks and in this case too, the group of experts indicated a clear preference in favor of "test" cigarettes.

Example 8

The procedure was as indicated in the previous example but using an emulsion obtained by mixing the following ingredients (parts by weight): Gum arabic 12 Malto-dextrin ¹⁾ (Maltrin-Glucidex, registered trademarks) 100 Manucol ²⁾ LF 2 Capsul ³⁾ 100 Arlacel ⁴⁾ 20 50 Demineralized Water 736 Total 1000 1) to 4) see Example 5

The flavor of the “test” cigarettes is entirely comparable to that obtained by the use of the emulsion according to Example 5.

In the examples described above, the emulsion was prepared as follows: In a suitable container, the water was stirred slowly using a magnetic stirrer or a propeller stirrer. The solid components formed by the water-soluble support (such as starch, dextrins or alginate) were added slowly in small portions. The medium is then left to swell and dissolve at room temperature, after which the emulsifier first and the aroma then have been added to the aqueous solution kept stirring until a homogeneous and fine emulsion is obtained.

Claims (9)

1. Process for the aromatization of tobacco leaves or tobacco particles of natural or artificial origin by means of a volatile, water-immiscible active flavouring substance, characterized in that said flavouring substance is put into intimate contact with the tobacco leaves or tobacco particles by directly spraying onto their exposed surface an emulsion obtained by admixture of the flavouring substance with an aqueous solution of a hydrosoluble carrier in the presence of an emulsifying agent.
2. Process according to claim 1 characterized in that the hydrosoluble carrier consists of polyvinyl acetate, polyvinyl alcohol, dextrines, starch, gelatine, vegetal gums, proteins, alginates, carrageenans, pectins, xanthanes, carboxymethylcellulose, methylcellulose or hydroxyethylcellulose.
3. Process according to claim 1, characterized in that the emulsifying agent consists of a mono- or a diglyceride of a fatty acid, an ester of a fatty acid with sorbitol or with a saccharide, or an ester of tartaric acid, citric acid, ascorbic acid or lactic acid.
4. Process according to claim 1, characterized in that the emulsion is formed of:

   a) 0.5% to 20% of active volatile flavouring substance,

   b) 5% to 30% of hydrosoluble carrier,

   c) 0.1% to 10% of emulsifying agent, and

   d) the remainder water.
5. Process according to claim 1 characterized in that the emulsion is used at a concentration of 5% to 15% by weight relative to the weight of the treated tobacco leaves or particles.
6. Smoking article consisting essentially of a tobacco material flavoured with an emulsion composed of a volatile water-immiscible active flavouring substance and an aqueous solution of a hydrosoluble carrier and an emulsifying agent.
7. Smoking article according to claim 6, characterized in that said hydrosoluble carrier consists of polyvinyl acetate, polyvinyl alcohol, dextrines, starch, gelatine, vegetable gums, proteins, alginates, carrageenans, pectins, xanthanes, carboxymethylcellulose, methylcellulose or hydroxyethylcellulose.
8. Smoking article according to claim 6, characterized in that the emulsifying agent consists of a mono- or a diglyceride of a fatty acid, an ester of a fatty acid with sorbitol or with a saccharide, or an ester of tartaric acid, citric acid, ascorbic acid or lactic acid.
9. Smoking article according to claim 6, characterized in that the emulsion is formed of:

   a) 0.5% to 20% of active volatile flavouring substance,

   b) 5% to 30% of hydrosoluble carrier,

   c) 0.1% to 10% of emulsifying agent, and

   d) the remainder water.