US2000855A - Method of denicotinizing tobacco - Google Patents

Description

Patented May 7, 19 35 7 2,000,855 METHOD OF DENICOTINIZING TOBACCO Ludwig Max Llppmann and Arnold Faitelowltz, Berlin, Germany; said Faltelowitz assignor to said Lippmann No Drawing. Application March 22, 1932, Serial No. 600,557. In Germany April 1, 1931 Claims. (01. 131-8) 5 pletely or remove all nicotine contained therein simply by way of fermentation, a considerable proportion of nicotine remaining in the fermented tgbtacco leaves,.in an even more firmly adhering s a Furthermore, it is known, that nicotine can or will be partially degraded or removed from tobacco upon addition of suitable substances for securing an alkaline or acid condition, but denicotinization to a complete or even to a predetermined extent cannot be attained in this way either.

In the known reduction of the proportion of nicotine contained in tobacco leaves by means of fermentation the denicotinizing action of the fermenting bacteriasoon ceases.

Now we have found that tobacco acquires, during the fermentation process, a high degree of alkalinity by which the vital functions of the microbes actingto decompose the albuminous substances of the tobacco and reduce the prothe. form of leaves or parts thereof, to the action of fermentation with admission or introduction of air and balancing or neutralizing the excess of alkalinity resulting from the action of the bacteria or microbes, by addition of a suitable acid or the like.

Highly alkaline tobacco can be treated, prior r to said fermentation, with pure water, whereas water, in order to be in the desired initial condi tion. In case of acid tobacco, particularly cigarette tobacco, however, pure water without any addition of alkali may just as well be used in the preliminary treatment, provided that care will be taken for a sufficient admission of air. The fermentation setting in thereafter in the subsequent step will automatically produce the required basic condition in such'a case.

According to our present method it is suflicient in many cases to only moisten the tobacco so that a solution or extract will not form, but if desired or required, in other cases, water in excess may be used so that the tobacco will be submerged or covered by a layer of water and will be subjected to the fermentation and denicotinization process in the presence of the excess water or extract formed, a separation of the latter from the tobacco not being required.

The reiterated-or continuous addition of suit: able acids during the fermenting process will prevent the alkalinity of the tobacco from rising too high while at the same time the escape of volatile bases, particularly aroma bases, will be avoided thereby.

A slightly alkaline condition of the tobacco and extract formed and consequently the denicotinizing action of the microbes can be maintained also without any addition of acids, since, ifair is continuously supplied or admitted, the evolved volatile bases will be removed by the air current which obviously must be passed through from'the tobacco, subjecting the extract to fermentation with admission of air and neutralizing the same by adding a suitable acid thereto, and uniting the said extract partially or totally freed' from nicotine and partially concentrated by evaporation, with the lixiviated tobacco leaves.

According to the present invention the said excessive or additional alkalinity of the tobacco extract can be reduced by passing a powerful current of air therethrough,.while the water lost by evaporation is replaced from time to time by fresh water supplies, until all or part of the nicotine, as desired, has been removed from the tobacco leaves. The volatile bases evolved and expelled in this way from the extract are collected in any appropriate manner and returned, together with the extract, either partially or totally, to the tobacco leaves for aromatizing purposes, or aroma-conferring substances from any other source may be added.

According to the present invention, a strong tothe leaves.

bacco extract of alkaline reaction containing microbes acting to decompose albuminous substances and to decompose nicotine, can be used in lieu of a slightly alkaline liquid. This will be of particular advantage when obnoxious microbes predominate over the microbes acting to denicotinize the tobacco. As compared with the usual addition of tobacco bacteria the vitality of the useful microbes always present in tobacco leaves will be promoted thereby at the same time.

The following examples will serve to illustrate the nature of the invention, but they are merely typical cases and can be varied without departure from the nature of the invention.

Example 1 A batch of tobacco leaves moistened with pure water, slightly alkaline water or an alkaline tobacco extract so as to be in a soft condition and easily to cut, and having an average pH value of about 8 is divided into heaps of about 100 kg. each piled up to aiford ready access of airto To this end the tobacco may be stacked insuperposed layers upon a perforated support. The temperature of the room in which this is done, is kept preferably at 30 to 40 C. and a cloth soaked in a suitable organic acid such as acetic acid, is spread over in contact with each of the several individual layers of the heap, the height of the single layer amounting to about The organic acid will tend to pass over from the cloth to the tobacco leaves adjacent to the cloth, by diffusion, so that volatile bases present 'in the leaves will be precipitated in the form of salts. After 6 to 12 hours the .heaps are relaid, depending upon the effect brought about by the reaction. As the leaves thus come in contact with other leaves again and again, the acid will disperse throughout and act on the basses adhering to leaves of other portions of the heap.

Instead of using a cloth for the introduction of the organic acid the latter can be supplied to the tobacco leaves immediatelyin the form 01' a mist or spray, by sprinkling or by atomization. Intensive supply of air will act to promote the progress of the reaction, particularly in case of employing air enriched as regards its oxygen content.

The process, that is the piling up, relaying and acidifying of the heaps constituting the batch of tobacco leaves under treatment, is discontinued when the desired degree of denicotinization and decomposition of albuminous substances has been attained. Judging from our practical experience about 66 per cent of the nicotine originally contained in the tobacco leaves are removed in this way, on an average, after eight days of treatment. But the. process or treatment may be continued for a longer period when it is desired or preferred to decompose and remove all of the nicotine present in the leaves.

Example 2 125 g. of tobacco leaves containing about 2.16 per cent of nicotine are placed in a suitable vessel and water is added sufficient to cover the leaves. At the bottom of the vessel there are provided a number of aerating devices equipped with fine nozzles so as to cause the air forced therethrough to rise in the liquid in the form of minute bubbles. Pure air is continuously forced by means of a suitable pump or-the like, through the said devices, so that the noise of the effervescing air will be audible and a; dense, creamy foam will be produced on the liquid. At the same time acetic acid is added slowly in the form of minute drops, say about 300 droplets per cubic centimetre of acetic acid, but sufflcient, as regards the total amount, not to allow the alkalinity of the liquid to grow too high.

After 4'7 hours no nicotine can be detected any longer in the liquid or extract which subsequently is to be neutralized by means of acetic acid and inspissated by evaporation in any suitable manner without being separated from the tobacco leaves.

Example 3 Tobacco leaves are treated in the same way as described in the Example 2, until they are completely denicotinized which as above stated, will take about 47 hours. Subsequently the tobacco leaves are taken out of the vessel and squeezed out moderately. The liquid or extract left in the vessel is neutralized by means of acetic acid and thereafter concentrated moderately by evaporation. The tobacco leaves then are subjected to a drying treatment and subsequently impregnated with the partly or-moderately condensed extract in any appropriate manner so as to be re-united therewith.

Example 4 Tobacco leaves containing about 1.3 percent of nicotine are placed in a suitable vessel and three times the amount or weight of water is added thereto, whereupon a strong current of air is injected into the liquid to pass therethrough. Water lost by evaporation is continuously replenished, while the temperature of the injected air and of the water is kept at such a point that approximately the temperature provoked by fermentation will be maintained. After about 54 hours all nicotine has disappeared so that further addition of water is to be discontinued and the tobacco leaves can be dried, preferably by means of an air current. The volatile organic bases ab- Example 5 1000 g. of tobacco leaves containing about 1.5 per cent of nicotine are lixiviated in a suitable vessel until they are absolutely free from nicotine, and subsequently squeezed out and dried; The extract thus recovered and amounting, by volume, to about 6000 cm. is treated with air by passing an intensive current of air therethrough, while at the same time the water lost by evaporation is replenished continuously. The temperature of the injected air and of the water is kept at such a point that approximately the temperature provoked by fermentation will be maintained. After about 20 hours all nicotine has disappeared, when addition of water is stopped and the extract condensed to about 1000 g. by evaporation. The thus be readily understood and therefore, further de-- tail description is deemed unnecessary. It will be evident, however, that our invention, while still be adhered to in its main essentials, may be varied and adapted in many ways, according to therequirements desired or most suitable under different circumstances, and we, therefore, aim in the appended claims to embrace all modifications falling fairly within the scope of our invention.

What we claim is:

l. A m hod of denicotinizing tobacco comprising the steps of wetting tobacco containing the usual bacteria, disposing the wetted tobacco loosely in layers and allowing the latter to stand with access of air thereto to produce fermentation of the tobacco, continuously adding acid to the extent necessary to neutralize the amino bases resulting from the fermentation, and drying the tobacco.

2. A method of denicotinizing tobacco comprising the steps of: wetting tobacco containing the usual bacteria, adding a weak alkali to bring the tobacco into a weakly alkaline condition, disposing the wetted tobacco loosely in layers and allowing the latter tostand with access of air thereto to produce fermentation of the tobacco, continuousiy adding acid to the extent necessary to neutralize the amino bases resulting from the fermentation, and drying the tobacco.

3. A method for denicotinizing tobacco comprising the steps of: wetting tobacco containing the usual bacteria, disposing the wetted tobacco loosely in layers and allowing it to ferment, passing a current of air through the layer of tobacco to expel the resulting amino bases, collecting the expelled amino bases, and returning the latter to the tobacco; 1

4. A method for denicotinizing tobacco com-- prising the steps of: treating tobacco containing the usual bacteria with a weak alkali to bring it into a weakly alkaline condition, wetting the treated tobacco, disposing the wetted tobacco loosely in layers and allowing it to ferment, passing a current of air through the layers of tobacco to expel the resulting amino bases, collecting the expelled amino bases, and returning the latter to the tobacco.

5. A method for denicotinizing tobacco comprising the steps of: wetting tobacco containing the usual bacterial, disposing the wetted tobacco loosely in layers and allowing it to ferment, passing a current of air through the layer of tobacco to expel the resulting amino bases, and adding ammo-conferring substances to the tobacco.

LUDWIG LIPPMANN. ARNOLD FAI'I'ELOWITZ.