EP0580725B1 - Sheet material for a smokable product comprising a flavouring substance - Google Patents

Abstract

A method for preparing a sheet material for the manufacture of smokable products such as cigars, cigarettes or the like, wherein flavouring substances or compositions are added to the pulp during material manufacture for release only when the smokable product is lit, said substances being incorporated by molecular encapsulation or complexing in cyclodextrins, and wherein steps are taken to ensure that all of said flavouring substances are incorporated in the cyclodextrins. A sheet material produced by the above mentioned method is also provided for wrapping a smokable product or for use as a leaf of reconstituted tobacco manufactured according to a known paper-making technique.

Description

The present invention relates to a sheet material, in which is incorporated at least one aromatic substance, intended for the manufacture of smoking products, such as cigarettes, cigars or similar products, as well as the smoking products which comprise such a material .

The invention aims to prevent the loss or premature modification of at least one aromatic substance before smoking the product, without adversely modifying the smoke and without the substance being detectable before the smoking of the product.

It also aims to release throughout the smoking of the product at least one aromatic substance in the primary and / or secondary smoke stream at a sufficiently low temperature so as to avoid thermal degradation of said substance.

The sheet material according to the invention can be used as an envelope for the smoking product.

It can also be used as a reconstituted tobacco leaf, made by a well-known papermaking technique.

It has already been proposed to incorporate aromatic substances or not, in the very pulp of papermaking.

Thus, in US patent 2886042 (REYNOLDS) it is proposed to dissolve sodium salts and potassium in the initial pulp of paper but mainly in order to improve the qualities of combustion of this paper and its behavior.

In patent EP 0251132 (SHIBANAI), it is proposed to include substances, in particular perfumes, in cyclodextrins to form molecular inclusion compounds and to mix them in the pulp and the papermaking water and, especially wrapping paper.

In this patent, this molecular inclusion must not be total, because if this were the case, the paper would not emit any odor in itself, which is the aim sought by this patent.

There is talk of a prolonged aromatic effect and it is due to the fact that molecules are partly adsorbed on the cyclodextrins or in emulsion in the mixture and that they gradually evaporate from the latter even when it is deposited on the dough during manufacture. It is never suggested that the cyclodextrins or the inclusion complexes be subjected to a thermal effect which degrades them to release the aromas.

In patent GB-A-1,171,043, it is proposed to incorporate in liquid form aromatic substances in microcapsules with a maximum diameter of 40 μm (different from cyclodextrins) produced by complex coascervation of an emulsion of a oily product insoluble in water and make a grout of these capsules in water with a natural adhesive.

It is not molecular encapsulation.

In all previous documents, no provision is made for the aromatic substances incorporated in paper intended to serve as an envelope for a smoking product are protected before consumption of the product and are released at a fairly low temperature, that is to say before being subjected to the high temperatures of the stinger during the smoking of the product , both in free combustion and in forced combustion.

To this end, the invention relates to a process for the preparation on a paper machine of a sheet material intended for the manufacture of smoking products, such as cigars, cigarettes or the like, in which the same paste is introduced for manufacturing said material flavoring substances or preparations intended to be released only upon combustion of the smoking product and which are included, by molecular encapsulation or complexation, in cyclodextrins, characterized in that a complex of encapsulation of flavoring substances in cyclodextrins in the form of a powder in a suspension solution, at a temperature below 15 ° C., the suspension solution is introduced into the size-press part of the paper machine and a drying, the flavoring substances not yet included in the cyclodextrins being eliminated by evaporation during drying.

Due to this total inclusion, said aromatic substances do not migrate into tobacco and are preserved until the moment when, by thermal degradation caused by the advance of the sting of the lit product, the cyclodextrins suddenly release part of said aromatic substances which they protect, this brutal release continuing gradually throughout the smoking of the product.

Apart from said aromatic substances, the material can obviously also be provided with other types of substances, for example intended to give off a smell naturally, without having to be thermally degraded. They do not then have to be included or complexed like the said substances.

Examples of manufacturing the materials of the invention are given below.

- EXAMPLE 1 -

Kneaded at room temperature (15 to 25 degrees C), a mixture consisting of three parts of B-cyclodextrin, in powder form and a part of water until a homogeneous dough is obtained.

A mixture of about 13% by weight, relative to the B-cyclodextrin, of vanillin presolubilized in ethyl alcohol is mixed.

Mix until the complex is obtained. It is dried in a ventilated oven for about 12 hours at 40 degrees C.

The complex is treated by heating at 100 degrees C for 24 hours.

The powder thus obtained is added with stirring in water at a temperature below 15 degrees, and at a concentration of 4%. The water is eventually salified. The solution thus produced is maintained at a temperature preferably 15 degrees lower, and deposited in the "size press" part of the paper machine.

The paper machine rotates at 288 m / min in width of 3.65 m. The consumption of the "size press" is around 20l / min.

The settings are made so as not to change the grammage of the desired paper.

The paper obtained contains 4% in total, relative to the paper, of B-cyclodextrin / vanillin complex. This paper has no odor and is used to make cigarettes with a mixture of blond tobacco from a commercial cigarette.

These cigarettes are tasted by a panel of experts. They note a subtle and pleasant orientation towards sweet, vanilla sweet notes of secondhand smoke without modifying the pleasantness of primary smoke.

- EXAMPLE 2 -

The procedure is the same as in Example 1 to prepare the complex, but the vanillin is replaced by γ-undecalactone in the same proportions. The powder thus obtained is added with stirring in water at the same concentration, but previously added with a suspensoid such as the biopolymer of Rhodopol BP 23 brand manufactured by Rhône-Poulenc.

The primary and secondary fumes of cigarettes made with this paper and with a mixture of blond tobacco were strongly flavored in the chosen note.

- EXAMPLE 3 -

The encapsulation of (-) carvone is carried out using a mixture of 90% B-cyclodextrin and 10% PMCD (partially methylated cyclodextrin manufactured by Ringdex Company). The procedure is the same as for Example 1.

The smoke from cigarettes made with this paper has an aromatic "spearmint" note. The irritation from primary smoke is reduced and the tobacco taste is reinforced. Second-hand smoke is sweeter.

- EXAMPLE 4 -

A mixture consisting of one part of B-cyclodextrins, in powder form, and three parts of water is kneaded at room temperature (15 to 25 degrees C) until a homogeneous mixture is obtained.

1/10 of a part by weight of a coumarin flavor is added.

It is dried at a temperature below 40 degrees C for approximately 12 hours.

Wash with an appropriate solvent to remove the unencapsulated flavor.

It is ground - followed by optional sieving to obtain a powder with a particle size of preferably between 1 and 100 μ.

The powder obtained is suspended in water and applied in a "size press" in the papermaking process (alone or in admixture with other compatible additives or fillers). The concentration is adjusted according to the desired quantity, the deposition rate and the speed of the machine.

- EXAMPLE 5 -

25.5 kg of pulverulent B-cyclodextrin and 2.5 kg of flavor are kneaded, dry, for 15 to 20 minutes, at room temperature. Add the 28 kg of dough obtained from 51 kg of cold water and brew for 30-40 minutes at a fairly low temperature, below 15 degrees.

The mixture thus encapsulated is placed in solution-suspension in 649 kg of water supplemented with 0.2% of Rhodopol BP23, serving as a suspensoid.

The solution obtained, maintained at a temperature below 15 degrees, is deposited in the "size press" part of the paper machine. During drying, the aroma molecules not yet included in the cyclodextrins are eliminated by evaporation.

The paper obtained according to the invention does not have an odor until it is burned, then the aroma is released, all the while smoking, suddenly, by thermal degradation of the cyclodextrins, around 280-300 degrees C, a few millimeters. before the sting, without having to undergo degradation at the very level of it, that is to say at 800 degrees C.

- Example 6 -

A reconstituted tobacco is produced according to the usual papermaking technique. However, the concentrated aqueous solution obtained from the maceration juice of tobacco dust in water is cooled, then maintained at approximately 15 degrees C, until the application in "size press" on the paper machine.

On the other hand, the encapsulation of an essential oil of tobacco is carried out according to the process described in the example. 4 and so as to obtain 6% of complexed essential oil.

This complex is suspended in the concentrated aqueous solution which is applied in the "size press" part of the paper machine. The rate of introduction of the complex is chosen as a function of the flow rate of solution, the speed of the machine, the rate of ascent of water in a known manner and in such a way that 0.1% of aromatic fraction is obtained in the final product.

The reconstituted tobacco thus obtained is introduced at a rate of 20% into the blond mixture of a cigarette.

Cigarettes made with this mixture are compared with other cigarettes prepared with an identical mixture but with reconstituted tobacco, without cyclodextrins. The first, oriented in the American line more markedly than the second, are judged by a panel of experts.

- EXAMPLE 7 -

We make a paste composed of tobacco dust (10 to 15% of carboxymethyl cellulose (2%) and water (80 to 90%).

The dough thus obtained is transferred by pumping to the feed hopper of a dryer which is composed of a stainless steel strip and a drying tunnel, heated to about 150 degrees C. A deposit is obtained on the strip of the dryer dough with a uniform layer about 0.5 mm thick. Just before entering the drying tunnel, spread on the dough, using a vibrator, in the form of powder of beta-cyclodextrin-vanillin complex obtained according to Example 1. The amount used is 5% relative to the dry matter of the dough.

Homogenized tobacco obtained after drying has no odor and is used to make cigarillos with a mixture of commercial tobacco.

These cigarillos are tasted by a panel of experts. They note a softening of the smoke and an orientation of it towards vanilla notes.

Claims (1)

1. Method of preparing, on a paper machine; a sheet material intended for the manufacture of products for smoking, such as cigars, cigarettes or similar products, in which aromatic substances or preparations are introduced into the actual pulp for manufacturing the said material and are intended to be released only at the moment of combustion of the smoking product and are included by molecular encapsulation or complexing in cyclodextrins, characterised in that an encapsulation complex of the aromatic substances in the cyclodextrins in the form of a powder in a suspension solution is maintained at a temperature of less than 15°C, the suspension solution is introduced into the size-press part of the paper machine and drying is carried out, the aromatic substances not yet included in the cyclodextrins being removed by evaporation during drying.