UA75021C2 - Method for tobacco processing by reducing the content of nitrosamine and a product obtained by this method - Google Patents

Abstract

Methods of reducing the content of and preventing formation of carcinogenic nitrosamines in harvested leafy plants such as tobacco and marijuana are disclosed. The methods are directed to subjecting the plant to microwave and/or higher frequency radiation, at appropriate times in the cure cycle. With tobacco, products suitable for human consumption, such as cigarettes, cigars, etc., can be made in accordance with the present invention, having contents of tobacco-specific nitrosamines on a par with fresh-cut, green tobacco. In preferred embodiments, the resultant tobacco products are dried, golden-yellow leaves having almost negligible amountsof the known carcinogens NNN and NNK, in comparison to conventionally cured tobacco.

Description

Description of the invention

According to the invention, a method of processing tobacco is proposed to reduce the content of harmful nitrosamines, which are usually contained in tobacco, or to prevent their formation. This invention also relates to a tobacco product with a low nitrosamine content.

This application is a partial continuation of the application Me08/879905 of June 20, 1997, which is a partial continuation of the application Me08/757104 of December 2, 1996, which is a partial continuation of the application Me08/739942 of October 3, 1996, which is now rejected and which is a partial continuation application Mo08/725691 dated September 23, 1996, 70, which is now rejected and which is a partial continuation of application Mo08/671718 dated June 28, 1996. The submitted application and the declared applications, with the exception of application Mo08/671718 dated June 28, 1996, are priority to the previous application MobO/023205 dated August 5, 1996.

The use of microwave irradiation for drying agricultural products was previously described. The use of microwave irradiation for harvesting tobacco is disclosed by Hopkins in patent 79 US Mo4430806. In US patent Mo4898189, Wochnowski proposes to use microwave irradiation to process green tobacco in order to control the moisture content during preparation for storage or transportation. US patent Mo3699976 describes how microwave irradiation kills tobacco parasites.

Moreover, methods of impregnating tobacco with inert organic liquids for extracting loosened organic materials with a washing agent have been disclosed, in which the mixture is subjected to microwave irradiation (US patent Mo4821747). In other embodiments, the use of microwave irradiation as a means of drying pressed material containing tobacco is disclosed (US patent Mo4874000). In the patent

USA Mo3773055 Stangis disclosed the use of microwave irradiation for drying and fluffing cigarettes made from wet tobacco.

Previous attempts to reduce the resin content | harmful carcinogenic nitrosamines were initially included in the use of filters when smoking tobacco. In addition, attempts were made to use additives to block the effects of harmful carcinogens in tobacco. These efforts to reduce tobacco-related cancer incidence have been unsuccessful. Fresh-cut green tobacco is known to be virtually free of nitro-substituent carcinogens. |See, for example, Virnik et al., "Empesi oi Ai-Sygipd op (She SpPetisai!

Sotrozyop oi Torasso" ("The effect of air drying on the chemical composition of tobacco"), Kesepi Admapsez ip Torasso --

Zsiepse, Mo/.21, rr.39 ei ed., Zutrovicht Rgoseediprdz 49!" Meeiiipud Torasso Spetiviv Bevzeagsp Sopieegepse, Zeri. CM 24-27, 1995. And ehipdiop, KepiisKu (hereinafter referred to as "Virnik et al... However, dried tobacco is known to contain a number of nitrosamines, including the harmful carcinogens M'-nitrosonornicotine (NNN) and o 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NPB).These nitrosamines are believed to are formed after harvest, during the drying process, as described below. Unfortunately, fresh-cut green tobacco is not suitable for smoking or other consumption.

In 1993 and 1994, Barton et al. at the University of Kentucky, certain experiments regarding tobacco-specific nitrosamines (STNA) were completed, as reported in the abstract, | Kedysiop oi Migie-Migodep apa

Torasso M'-BZresiiis Miigozatipez ip Ai-Scgei Torasso Vu Eiiemaipd Oguipd Tetregaishgev" ("Reduction of Nitrite Nitrogen and M'-specific nitrosamines for tobacco during drying of tobacco in air by increasing the drying temperature"), Adgopotu 5 РНуорайойоду доипи Мейпо, SOKEBTA, Ohio 1995. Barton et al reported that drying harvested tobacco leaves for 24 hours at 71 C at various stages of air drying, including end of yellowing (KP), KP-3, KPya-5, etc. , resulted in some reduction of nitrosamines. Reference was also made to freeze-drying and microwave treatment on certain samples, without details or results. The applicant confirms that in the actual treatment that forms the basis of this abstract, which -1 but carried out by Barion et al. in University of Kentucky, microwave processing is considered unsuccessful. Some aspects of Barton et al.'s 1993-1994 research were previously reviewed by Wirnick et al., pp. 54-57, 1 under the heading "Modiei Aig-Sygipd" ("Mo modified air drying")). Virnik et al postulate that rapid drying of tobacco leaf samples taken at different stages of air drying at 702 for 24 hours, 5p removes excess water and reduces the growth of microorganisms; therefore, the accumulation of nitrite and STNA was avoided. In table II on p. 56, Virnik et al., some data from Barton et al. are included. about the content of nitrites and STNA in the laminae and main veins of leaves in samples KU160 and KU171. Freeze-drying and flash-drying test data were included, but microwave-treated samples were not mentioned. The article contains the following conclusion.

This can be completed at the stage when it is possible to reduce the content of nitrites and the accumulation of STNA in the laminae and main veins of the leaves when using heat (7022) for dark tobacco after the loss of the integrity of the leaf cells. Rapid drying of tobacco leaves at this stage of drying reduces the microbial activity present during (F) slow drying at ambient temperature. It should be added, however, that such processing reduces the quality of tobacco leaves.

On p. 56. articles by Virnik et al. as an example of 2-stage drying, the traditional tobacco drying in "Skronowski" in Poland is also discussed, in which the tobacco is first air-dried, and when the leaf plate has turned yellow or brownish, the tobacco is exposed to a temperature of 659C for 2 days to dry the stem. Analysis of tobacco production in this way showed that there are low values of both nitrites and STNA, i.e., less than 1 Ωkg/g and 0.6-2.1 μg/g, respectively. Virnick et al theorized that these results were the result of rapid heating that prevented further bacterial growth. Virnik et al. also reported, however, that low 65 nitrite and STNA contents, less than 15 µg nitrite and 0.2 µg STNA, were obtained for air-dried tobacco in Poland.

One objective of the present invention is to substantially eliminate nitrosamines or reduce their content in tobacco intended for smoking or other consumption.

Another goal of the presented invention is to reduce the carcinogenic potential of tobacco products,

Including cigarettes, cigars, chewing tobacco, snuff and tobacco chewing gum and lozenges.

A further goal of the presented invention is to significantly get rid of STNA or significantly reduce their content, including M'-nitrosonornicotine (NNN), 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NPB),

M'-nitrosoanatabin (NAT) and M'-nitrosoanabasin (NAB) in this tobacco product. another object of the present invention is to process the uncured tobacco after an acceptable time after 7/0 Harvest so as to complete the drying process without adversely affecting the tobacco intended for human consumption.

Another objective of the present invention is to reduce the content of STNA in fully dried tobacco.

A further aim of the present invention is to reduce the content of STNA, in particular INN and NPB, their metabolites in people who smoke, consume or otherwise absorb tobacco in any form, providing a suitable 7/5 tobacco product for human consumption, which contains a significantly reduced content of STNA , and therefore reducing the carcinogenic potential of such a product. Predominantly, the tobacco product is cigarettes, cigars, chewing tobacco or tobacco-containing chewing gum and tablets.

The above-mentioned and other objectives and advantages according to the present invention can be achieved by reducing the content of nitrosamines formed or preventing this formation in harvested tobacco plants,

Which includes treating at least part of the plant with microwave irradiation, while the aforementioned part is not dried and is in a state susceptible to reducing the content of nitrosamines or delaying their formation, for a period of time sufficient to reduce the content of or substantially prevent the formation of at least one nitrosamine. high school

It is better that in the method according to the invention, the operation of microwave irradiation was carried out on the tobacco leaf or its parts after the beginning of yellowing of the leaves and before the significant accumulation of STNA in the leaf. and)

It is also preferable that, in the method according to the invention, the operation of microwave irradiation precedes a significant loss of integrity of leaf cells.

According to an even better embodiment of the invention, the tobacco is smoke tobacco and the operation of microwave irradiation occurs within 24-72 hours after harvesting, and preferably within 24-36 hours after harvesting. with

According to other embodiments of the method, the collected tobacco was kept before the operation of microwave irradiation in a controlled environment at a temperature higher than the ambient temperature. at

Preferred aspects of the method include the operation of physically pressing the leaves to remove excess moisture therefrom before microwave irradiation of the tobacco leaves, which preferably includes stems, to ensure more uniform drying with the microwave apparatus. This operation is conveniently carried out when the leaves pass into the microwave resonator through cylindrical rotating rollers located in pairs at appropriate intervals. "

According to a further preferred embodiment of the invention, the microwave irradiation has a frequency of approximately 900 pl») s to approximately 2500 MHz, and acts on the plant for at least 1s, and preferably from 10s to 5 minutes at a predetermined power. The strength usually determines the length of time during which the tobacco is processed;" microwave radiation, and can range from 600-1000O0watts when using an ordinary kitchen model of a microwave thermo-cabinet, up to several hundred or more kilowatts for industrial multimode units. Predominant powers of devices intended for processing leaves of manual harvesting -I range from 2 to 75 kW, preferably 5 to 50 kW, which allows for relatively fast processing.

Also, according to the present invention, it is better that microwave irradiation is applied to the leaf or its part for a sufficient time to effectively dry the leaf, but without burning, so that it is suitable for human consumption.

The present invention also provides treatment of leaves with microwave irradiation to prevent the normal accumulation of at least one STNA, such as M'-nitrosonornicotine (NNN), such as 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NPB ), M'-nitrosoanatabin (NAT) and M'-nitrosoanabasin (NAB).

The present invention in its broadest scope also covers a tobacco product containing non-green tobacco suitable for human consumption and having a reduced content of at least one STNA compared to conventionally dried tobacco.

F) According to the best embodiments of the invention, the product from non-green tobacco has a content of STNA (INN, NPB, NAB and NAT) of less than 0.2 μg/g, preferably less than 0.15 μg/g, and even better less than 0.1 μg /g, the IU content is less than 0.002μg/g, preferably less than 0.001μg/g, and even better less than 0.0005μg/g. 60 The present invention is also directed to a tobacco product containing dried yellow tobacco suitable for human consumption and having a reduced content of at least one STNA compared to conventionally dried tobacco.

According to the best embodiments of the invention, the product from yellow tobacco has a content of STNA (INN, NPB, NAB and NAT), INN content, and NPB content in the above-mentioned best limits. 65 According to other embodiments of the invention, the product from non-green or yellow tobacco contains non-green or yellow tobacco suitable for human consumption, which has a content of STNA (INN, NPB, NAB and NAT) within 2595 by weight of the content of such STNA in the freshly harvested crop green tobacco from which the product was made. It is preferable that the non-green or yellow tobacco product has an STNA content within the range of 1095 by weight, more preferably within the range of 595 by weight, and most preferably substantially approaching (eg within a few percent by weight) the content of such STNA in the freshly harvested tobacco crop from which the the product is made. It is also preferable that the non-green or yellow tobacco product suitable for human consumption comprises non-green or yellow tobacco having a content of at least one STNA selected from INN, NPB, NAB and NAT within 2595 by weight, preferably within 1095 by weight, even better within 595% by weight, and best substantially approaching (eg within several percent by weight) the content of such STNAs in the freshly harvested tobacco crop from which the product was made. 70 According to the following embodiments of the invention, the product from non-green or yellow tobacco contains non-green or yellow tobacco suitable for human consumption, having a content of STNA (INN, NPB, NAB and NAT) that is at least 75956 by weight, preferably at least 9095 by weight, more preferably at least 9595 by weight, and most preferably at least 9995 by weight less than the content of such STNA in a tobacco product of the same type, made from the same crop of tobacco as the product according to the invention, but which was manufactured without /5 the use of microwave irradiation or other technical methods designed to reduce the content

STNA It is also better that a product from non-green or yellow tobacco, containing non-green or yellow tobacco suitable for human consumption, should contain at least one STNA selected from INN, NPB,

NAB and NAT that is at least 75905 by weight, better at least 9095 by weight, even better at least 9595 by weight, and best at least 9995 by weight less than the STNA content of a tobacco product of the same type made from the same of the tobacco crop, as well as the product according to the invention, but without the use of microwave irradiation or other technical methods designed to reduce the content of STNA.

A preferred form of the present invention relates to a tobacco product containing tobacco with a reduced content of at least one STNA, which is produced by a method that includes treating the tobacco with microwave irradiation while it is uncured and susceptible to the formation of at least one c ov Retained STNA.

According to another embodiment, the present invention is directed to a method of reducing the content of at least one (8)

STNA in dried brown tobacco, comprising dehumidifying the dried brown tobacco, and treating the dehumidified tobacco with microwave irradiation at a predetermined power and with a predetermined duration of time.

In addition, the present invention includes the production of tobacco containing a reduced content of at least one STNA, which is produced by a method that includes dehumidification of dried brown tobacco, and treatment of the dehumidified tobacco with microwave irradiation with a predetermined power and a predetermined duration of time. Cha

According to the following embodiment, the present invention relates to a method of manufacturing a tobacco product, which includes the treatment of harvested tobacco leaves with microwave irradiation, while the aforementioned leaves are not dried and are susceptible to reducing the content of STNA or delaying the formation of STNA, for a period of time sufficient to reduce the content or substantially prevent the formation of at least one STNA in the time sheet, and with the formation of a tobacco product containing microwave-treated leaves, a tobacco product selected from cigarettes, cigars, chewing tobacco, snuff and tobacco-containing chewing gum and;" tablets

It has also been found that electromagnetic radiation having a frequency higher and a wavelength lower than that discussed above, and in more detail below, the microwave region, can be used to achieve -I the main objective of the presented invention, namely the reduction or substantial elimination of STNA in tobacco product when processing tobacco with such forms of energy within the same post-harvest time frame as discussed above for the microwave embodiment. Therefore, the invention also relates to a method of reducing the content or preventing the formation of nitrosamines in a harvested tobacco plant, which includes treating at least part of the plant with radiation having a frequency higher than the microwave range, while

The aforementioned part is not dried and is in a state susceptible to reducing the content of nitrosamines or delaying their formation for a time sufficient to reduce the content or substantially prevent the formation of at least one nitrosamine.

As in the case of microwave treatment, it is preferable that, in the process of the invention, the treatment operation of irradiation having a frequency higher than the microwave region is carried out on the tobacco leaf or part thereof after the initiation

F) yellowing of the leaves and prior to significant accumulation of STNA in the leaves. It is also better that, according to the method according to the invention, the operation of such irradiation was carried out before the leaves significantly lost the integrity of the cells.

The preferred sources of energy capable of producing such radiation are described below and include far-infrared and near-infrared radiation, ultraviolet radiation, soft X-ray or laser radiation, accelerated particles such as electron beams, X-rays, and gamma rays.

Figure 1 is a photograph illustrating "yellow" smoke virgin tobacco harvested 24-72 hours ago.

Fig. 2 is a photograph illustrating "yellow" smoked virgin tobacco with a reduced content of nitrosamines, which has been treated with microwave irradiation according to the invention. 65 Fig. 3 is a partial, side perspective, illustrating a mobile, industrial microwave apparatus that can be used in microwave processing according to the invention.

It should be added that practically drying tobacco is more of an art than a science, because the conditions during any drying process must be selected taking into account such factors as varietal differences, differences in leaves collected from different positions of the stem, differences between the barns used for drying, and changes in the environment during one or more seasons, especially unstable weather during air drying. For example, the practice of drying in smoke is to some extent empirical, and it is optimally carried out by people who have accumulated experience in this over a considerable period of time. Let's look, for example, (Reeiye ei aii, "Spetisai apa Viospetisai Spapdez Yuigipd

Te RiIse Sigipd OI Torasso" ("Chemical and biochemical changes during the drying of tobacco in smoke"), Kesepi Admapsez (p

Thorasso Zsiepse, MoY.21, rr.81 ei zed.,, Zutrovisht Rgoseeadipdz 497 Meeiiipd Spetiviv' Beveagsp Sopiegepse, 70 Berietreg 24-27, 1995, I ehipdiop, Kepiisku (hereinafter referred to as "Pil et al.")). Therefore, experts should understand that the external parameters of the presented invention, in its broadest forms, are variable depending to some extent on the careful combination of the above factors for a given crop.

According to a first preferred embodiment of the present invention, it is found that during the drying period there is a window in which the tobacco can be processed in a way that essentially prevents the formation of STNA. Of course, the precise 75 window during which STNA formation can be effectively eliminated or substantially reduced depends on the type of tobacco, the method of drying, and several other variables, including those mentioned above. According to this preferred embodiment of the invention, the window corresponds to the time frame after harvest, when the leaves are beyond the fresh cut or "green" stage, and until the time after which STNA and/or nitrites have substantially accumulated in the leaf; this time structure usually corresponds to the period and which leaf undergoes the yellowing process or is in the yellow phase, 2o before it starts to turn brown, to a significant loss of cell integrity. Unless otherwise clear from the context, the terms "substantial" and "substantial" as used herein generally refer to dominant or larger relative scales of reciprocal concessions. During this time frame, the leaves are susceptible to substantially preventing the formation of STNAs or reducing the content of any already formed STNAs by microwave irradiation of the tobacco at a predetermined energy level for a predetermined time duration, as discussed below. Microwave treatment essentially delays the normal formation of STNA, and produces dried, golden-yellow leaves suitable for human consumption. If STNAs have already begun to accumulate significantly i) usually by the end of the yellow phase, the use of microwave irradiation for leaves according to the invention effectively delays the period of natural formation of STNAs, therefore preventing any further significant formation of STNAs. When yellow or yellowed leaves are processed in this way at the most "-- optimal time of the drying period, the resulting tobacco product has a content of STNA essentially close to that of freshly picked green tobacco, while retaining its aroma and taste. with

According to other embodiments, the present invention discloses the treatment of dried (brown) tobacco to (3) effectively reduce the content of STNA in this dried tobacco, by dehumidifying the dried tobacco and treating the dehumidified dried tobacco with microwave irradiation, as described below.

The presented invention is suitable for processing collected tobacco intended for human consumption. Most of the studies, especially those related to STNA, have been conducted on tobacco. Freshly harvested tobacco leaves, called "green tobacco", do not contain known carcinogens, but green tobacco is not suitable for human consumption. The process of drying green tobacco depends on the type of tobacco harvested. "

For example, smoke virgin tobacco (light) is usually smoke-cured, while Barley and some dark 70 varieties are usually air-cured. Drying tobacco in smoke is usually continued for 5-7 days compared to 1-2 months of air drying. According to Peel et al., smoke drying usually consists of three stages: yellowing (35-4022) for about 36-72 hours (although others suggest that yellowing begins earlier than "» 36 hours, for example, for certain varieties of smoke virgin tobacco after about 24 hours), leaf drying (40-572C) for 48 hours, and main vein (stem) drying (57-752C) for 48 hours. Most of the chemical and biochemical changes begin during the yellowing stage and continue into the early stages of drying leaves. -i In the conventional smoke-drying process, the yellowing stage is carried out in barns. During this phase, the green layer of leaves successively loses color due to the disappearance of chlorophyll, with the corresponding appearance of yellow carotenoid pigments. According to the review by Peel et al., the yellowing stage of smoke-dried of tobacco ends when (av) closing the external air inlets in the bars, and maintaining a temperature of about 35-37 C. This 7 50 process uses a controlled environment, maintains either during the night, the humidity in the barns at the level of about 8595, limits the loss of moisture from the leaves, and allows the continuation of the metabolic processes of the leaves that began in the fallow. "6 The operator of the permanent control programs of the drying course, first observes the loss of chlorophyll and the green color of the leaves, and the appearance of the desired lemon to golden-orange color of the leaves.

The smoke virgin tobacco on which the tests described here were carried out has a specific difference, freshly picked green tobacco was placed in a barn for 24-48 hours at 38-432C, until the leaves became more or less completely

GF! yellow (see Fig. 1). Yellow tobacco therefore has a reduced moisture content, from about 9095 by weight when, green, versus about 70-4095 by weight when, yellow. At this stage, yellow tobacco contains essentially no known carcinogens, and the STNA content is essentially the same as that of fresh-cut green tobacco. This smoky virgin tobacco in the yellow stage is usually left for 6-7 days, after which the leaves turn from yellow to brown. Brown 60 smoke virgin tobacco typically has a moisture content of 11-1595 by weight. The transformation of tobacco from yellow to brown leads to the formation and significant accumulation of nitrosamines and an increase in the content of microbes. The exact mechanism by which STNAs are formed is not clear, but it is believed to be enhanced by microbial activity, with the involvement of microbial nitrate reductase in the production of nitrites during drying.

It is believed that STNAs are formed during the reaction of amines with nitrosating agents derived from nitrites, such as MO", M2Oz and M2O, under acidic conditions. Virnik et al. discuss the postulated formation of STNA on p. 43-45; a brief overview is provided below.

Tobacco leaves contain a large amount of amines in the form of amino acids, proteins and alkaloids. Tertiary aminonicotine (labeled (1) in the diagram below) is the major alkaloid in tobacco, while the other nicotine-type alkaloids are the secondary amines, nornicotine (2), anatabine (3), and anabasine (4). Tobacco also usually contains up to 595 nitrates and traces of nitrites.

Nitrosation of nornicotine (2), oanatabine (3) and anabasine (4) gives the corresponding nitrosamines:

M-nitrosonornicotine (NNN, 5), M'-nitrosoanatabine (NAT, 6) and M'-nitrosoanabasin (NAB, 7). Nitrosation of nicotine in an aqueous solution gives a mixture of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NPB, 8), (NNN, 5) and 4-(M-nitrosomethylamino)-4-(З -pyridyl)-1-butanal (NPA, 9). STNAs, which are usually less common, contain 70 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanol (NPBL, 10). 4-(M-nitrosomethylamino)-4-(3-pyridyl)-1-butanol (iso-NPBL, 11) and 4-(M-nitrosomethylamino)-4-(3-pyridyl)-butanoic acid (NPBEC, 12) . The formation of these STNAs from the corresponding tobacco alkaloids is shown schematically below, using the designations 1-12 mentioned above

It is reproduced according to Virnik et al., earlier, p. 44): ve Demethylation in in o ! Monday

M sn) m y M ory vn

Eat o Nicotine Fe Nornicotino 3 to Anatabin o 4 sho dnabaani nn Vitrification 77 panna Nitrosation sh

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And in NNN vu

Fo "w

Oxidation no that be AT her -- zora Mm-snz F) ts sno F) Iv to o da npA iz VPB MN o no N n | КО НАБ ой дурее сн чезастеняя: WORSENING

M nako i o iiivye NIBK k-SM, bure b "my Mo sya ko-NPBL Shk NPBL :z" It is now generally accepted that green, fresh-cured tobacco actually does not contain nitrites or STNA, and that these compounds occur during drying and tobacco storage. Research conducted during the past decade to determine the critical factors associated with the formation of STNA during tobacco drying has -1 395 identified several factors, which include the genotype of the plant, its maturity at harvest, drying conditions and microbial activity. (9) Studies show that nitrites and STNAs accumulate during air-drying at intervals starting at about the end of yellowing and ending when the leaves are fully browned, such as 2-3 weeks after harvest for certain air-dried varieties. air, and about a week after harvest ko 50 for the smoke-dried varieties. This is the time during which the integrity of the cells is lost, respectively, which is lost and flows out of the cells into the intercellular spaces of moisture. Therefore, with air drying, there is a short window in time when the cells have broken down, creating food suitable for microorganisms. Virnik et al. say that nitrites can significantly accumulate when the recovery of hidden nitrates ends, leading to the formation of STNA. 59 There are several published reports on the effects of microbial flora on tobacco leaves during growth and

GF) drying and on dried tobacco, as shown by Virnik et al.. However, the inclusion of microbial nitrite reductases in nitrite production is speculative. When, after the yellow phase, the cell structure is destroyed and nutrients become available to microorganisms, they can produce nitrites under favorable conditions, i.e., high humidity, optimal temperature and lack of oxygen. This is usually a rather short window in time when the water activity is still high enough, and the cell structure has decomposed.

According to the present invention, the formation of STNA in tobacco is significantly prevented or delayed by exposing the collected leaves to microwave irradiation under the conditions described herein. In the first preferred embodiment, tobacco leaves were subjected to microwave irradiation during the time between the onset of yellowing and a significant loss of cell integrity. For optimal results, it is better to pass the collected leaves through the microwave field in individual leaves, as opposed to a pile or bundle of leaves. Treatment of leaves in this way can be decisive for complete or substantial prevention of STNA formation, including known INN and NPB carcinogens.

According to preferred embodiments of the present invention, it is possible to obtain a product from non-green and/or yellow tobacco that is suitable for human consumption and has a reduced content of at least one STNA than conventional dried tobacco. Green or fresh-cut tobacco, as mentioned above, is usually unfit for human consumption; "off-green" as used herein means tobacco that has lost at least most of its chlorophyll, and includes without limitation partially yellow leaves, completely yellow leaves, and leaves that have begun to turn brown in places. In preferred embodiments, the non-green tobacco product contains STNA (INN, NPB, NAB and

NAT) less than 0.2 μg/g, better less than about 0.15 μg/g, even better less than about 0.1 μg/g, IU content /o less than about 0.15 μg/g, better less than about 0, 1 µg/g, more preferably less than about 0.05 μg/g, and the NPB content is less than about 0.002 μg/g, preferably less than about 0.001 μg/g, preferably less than about

О.00О5mcg/g. As mentioned above, the number of factors that can affect the formation of STNA in tobacco has been established, experts should understand that this number is not absolute, but mostly fluctuates within certain limits.

According to the invention, a tobacco product containing yellow dried tobacco suitable for human consumption and having a reduced content of at least one STNA than conventional dried tobacco is also proposed. According to preferred embodiments, the yellow tobacco product has a content of STNA (INN, NPB, NAB and NAT), INN content, and NPB content within the above limits.

According to other embodiments, the non-green or yellow tobacco product contains non-green or yellow tobacco suitable for human consumption, having a content of STNA (INN, NPB, NAB and NAT) within about 2590 by 20% by weight of the content of such STNA in freshly harvested green tobacco from which the product was made. Even more preferably, the non-green or yellow tobacco product has a STNA content of about 1095 by weight, more preferably within about 5905 by weight, and even more preferably substantially approaching (eg, within a few percent by weight) the STNA content of freshly harvested green tobacco from which the product was made. For example, the presented invention makes it possible to produce a product from tobacco that has a STNA content within the above-described limits, while ordinary dry-cured tobacco from the same crop produces many times more STNA than in freshly cut tobacco.

The presented invention can effectively fix the low content of nitrosamines found in freshly cut i) green tobacco. It is also preferable that the non-green or yellow tobacco product contains non-green or yellow tobacco suitable for human consumption that contains at least one STNA selected from IUU,

NPB, NAB, NAT, in the range of about 2595 by mass, better about 1095 by mass, even better about 595 by mass, and best significantly approached (for example, within several percent by mass) the content of the corresponding STNA in freshly collected green tobacco from which the product was made, in other words, the content of, for example, IU in tobacco according to the invention is reduced within the above-mentioned limits in relation to the content of IU (3 freshly cut green tobacco, or the content of IU in tobacco according to the invention is reduced in the above-mentioned limits in relation to the content of NNNNPAB in fresh-cut green tobacco, etc. To make these comparisons, fresh-cut tobacco is best analyzed for the content of STNA within about 24 hours after harvesting.

According to the following embodiment of the invention, the product from non-green or yellow tobacco contains non-green or yellow tobacco suitable for human consumption, having a content of STNA (INN, NPB, NAB and NAT) which is at least 7595 by weight, preferably at least 9095 by weight by mass, even better by at least 9595 by mass, and even better by at least 9995 by mass is lower than the content of such STNAs in a tobacco product of the same sample, made from the same crop of tobacco as the product of the invention, but which was dried without treatment with microwave irradiation or other operations specifically designed to reduce the content of STNA. ;" It is also preferable that the non-green or yellow tobacco product includes non-green or yellow tobacco suitable for human consumption, having a content of at least one STNA selected from INN, NPB, NAB, NAT, which is at least 75956 by weight, preferably at least 9095 by weight , more preferably at least 9595 by weight, and -and most preferably at least 9995 by weight lower than the content of such STNA in a tobacco product of the same type (eg, comparing cigarettes with other cigarettes) made from the same tobacco crop as o product of the invention, but which was dried without treatment with microwave irradiation or other technical techniques to reduce the content of STNA. In these embodiments, the mass fractions of STNA can be compared by taking, for example,

Cigarettes made using yellow tobacco dried according to the invention, and cigarettes made from yellow tobacco of the same crop, but dried in the usual way without microwave treatment

Kk irradiation.

The yellow stage, at which it is best to carry out the operation of processing tobacco leaves with microwave irradiation, can be broadly determined by one of the following methods: (a) when examining the color of the leaves, two When the green color turns significantly into yellowish; (b) when measuring the percentage of conversion of chlorophyll to sugars; (c) observing the onset of formation of any of the nitrites or nitrosamines, which usually coincides with

(f) at the end of the yellow phase, or (d) by measuring the moisture content of the leaf, for example when it has a mass fraction of moisture ka of about 4095 to 7095. If green tobacco is microwaved, the formation of nitrosamines is not delayed or prevented. However, when tobacco is treated with microwave irradiation after the onset of yellowing and before the loss of cell integrity or significant accumulation of STNA in the leaf, the observed reduction in their content, or prevention of the formation of nitrosamines, is sharp and unexpected, as shown in the data discussed below.

The optimal time to microwave harvested tobacco during the yellow phase depends on a number of factors, including varietal differences, environmental changes, etc. Therefore, within the allotted 65 time interval, starting from the beginning of yellowing (which is determined, for example, by the loss of the green color of the leaves) until the time when the leaves significantly lose the integrity of the cells (when they turn brown), experts should determine the optimal time for conducting microwave processing for any types of tobacco.

For example, for a given genotype, a sample of leaves can be examined by the methods described herein to measure the content of nitrite or STNA, to establish the appropriate time in a given drying cycle at which significant accumulation of STNA begins, or to establish the transition phase in which loss of cell integrity occurs. While the operation of microwave irradiation of leaves before a significant accumulation of STNA is the best form of embodiment of the method according to the invention, the principles of the invention can also be applied to tobacco leaves that are in the process of formation and already have a significant content of accumulated STNA. When microwave irradiation is performed at this late stage, further formation of STNA can be effectively delayed. 70 However, sometimes the leaves are completely dried, the STNA content is essentially stabilized, and the use of microwave irradiation is useless to reduce the STNA content, except in the case of dehydration described below.

When treated with microwaves in accordance with the present invention, the tobacco leaves typically have a reduced moisture content, i.e., less than about 1095 by weight, and more often closer to 595. If desired, the leaves can be dehumidified to typical limits for brown, dried tobacco (eg, about 11 -1595 for smoke virgin tobacco) for the manufacture of a tobacco product such as cigarettes.

The present invention is suitable for all types of tobacco, including smoke or light types, barley types, dark types, oriental/Turkish types, and the like. Within the guidelines set forth herein, skilled artisans should determine the most effective time during the drying period for the microwave operation to achieve the purpose and advantages of the present invention.

Preferred aspects of the process include the operation of physically pressing the leaves to expel excess moisture therefrom before treating the tobacco leaves, which preferably include the stalks, with microwave irradiation to ensure more uniform microwave drying. This operation can usually be carried out by passing the leaves through a pair of cylindrical rotation rollers located at a suitable distance before entering the microwave chamber. This pressing operation helps to squeeze moisture from the stem and, to a lesser extent, from the main veins and large canals of the leaves, and causes a better and more uniform drying of the product. The rollers can i) be made of hard rubber, plastic or steel and be of any desired length, and the best distance between them is about 0.3 to 0.bsm, but the distance is best chosen to adapt it to the thickness of one sheet, which can change. Rollers can be driven by a suitable motor through a belt or chain-diesel transmission. In addition to rotation rollers, you can use other methods of squeezing or pressing to obtain the same desired result; that are known to specialists. with

The above-described preferred embodiment of leaf pressing allows for high-speed production, since the stem does not need to be cut, and the microwave exposure time can be reduced. This embodiment is particularly favorable for tobacco leaves intended for the production of cigarettes, which usually contain some o

Зз5 Tobacco stalks as part of a mixture. Alternatively, the pressing operation can be omitted, if desired, when the stem is cut from the leaves and discarded.

According to another preferred embodiment, instead of pressing the leaves or cutting off the stem, the leaves can be steamed in the microwave. As with pressing, steaming whole leaves, including stems, can achieve a more uniform distribution of moisture in the stems and large leaf canals, resulting in more uniform microwave drying of whole leaves. As a result, when these special techniques have been applied, all the leaves, including the stems, can be used in the production of the tobacco product.

Although the details are known to those skilled in the art, results were obtained when the leaves were placed in a steamable vessel for a time sufficient to impart some degree of softness and flexibility to the leaves, usually between 30 seconds and 5 minutes.

The principles of the present invention can also be adapted for brown or already dried tobacco that has been dehumidified. At the same time, as a significant and unexpected decrease in the content of STNA, in particular, IUU and

NPB, was observed when dehumidified brown tobacco was subjected to microwave irradiation, but the results were not dramatic when the invention was applied to uncured yellow tobacco before the time when a significant content of STNA or nitrites should have accumulated in the leaf. However, additional wetting of dried leaves, such as spraying with sufficient water to effectively soak the leaves prior to microwaving the dehydrated leaves, reduces the STNA content as shown in the examples below.

Kk As stated above, when curing dried or brown tobacco, microwave irradiation itself has little effect on the nitrosamine content. However, it has been recognized that dehumidification of dried tobacco prior to microwave treatment contributes to the effect of microwave irradiation in the reduction of two nitrosamines. According to a first preferred embodiment, the dried tobacco product is moistened by adding directly to the leaves an appropriate amount of water, preferably at least about 1095 by weight to

F) maximum absorption capacity. Treatment of dried leaves with microwave irradiation, in any manner described herein with respect to uncured tobacco, reduces nitrosamine content as shown below.

The leaves can be moistened in any suitable way. If the dried tobacco is in a form other than leaves, such as processed "leaf" tobacco, it can be dehumidified like this, for example, 10-7095 by weight of water, and then microwaved. Suitable microwave conditions can be selected depending on the degree of moisture of the leaves, but usually within the parameters discussed above for the microwave treatment of yellow tobacco.

According to the present invention, microwave treatment of dehumidified brown tobacco preferably 65 Can reduce the content of STNA (INN, NPB, NAB, NAT), measured individually or collectively, by at least about 2595 by weight, preferably by at least 35956 by weight, and even more preferably by at least about by 5095 by mass compared to the content of STNA in dried brown tobacco before its dehumidification.

The term "microwave radiation" as used herein refers to electromagnetic energy in the form of microwaves having a frequency and length common to the microwave region. The term "microwave" usually refers to that part of the electromagnetic wave scale that lies between the far infrared and conventional high frequency (radio frequency ) spectrum. The range of microwaves extends from their length of about 1 mm and frequency of about 3000 MHz to a length of 30 centimeters and a frequency of slightly less than 1000 MHz.

The present invention preferably uses high power microwaves, usually at the lower end of this frequency range. In this selected frequency range, there is a fundamental difference between microwave heating and such a classical method as infrared radiation (for example, when cooking food): this is due to greater penetration, rapid heating to a depth of several centimeters, while infrared heating is much more superficial In the US, industrial microwave devices such as microwave ovens operate at standard frequencies of approximately 915 MHz and 2450 MHz, respectively. These frequencies are industry standard ranges. In Europe, microwave frequencies of 75 2450 and 896 MHz are usually used. Under well-balanced conditions, however, microwaves of other frequencies and lengths may be suitable for achieving the purpose and advantages of the present invention.

Microwave irradiation of different strengths can be generated depending on the desired application.

Microwaves are usually produced by a magnetron, with a power of 600-1000 W for a normal kitchen microwave (of course, about 800 W), and industrial devices have a power of up to several hundred kW, usually with the addition of block sources of about 1 kW. A magnetron can generate pulsed or continuous waves of appropriate high frequencies.

The resonator (or thermal cabinet) is a necessary connecting link between the microwave energy generator and the material to be heated. For the purpose of the present invention, any desired resonators can be used, as long as they are adapted to efficiently irradiate parts of the tobacco plant. c ov The resonator must be selected for the microwave generator for optimized power transmission to avoid energy dissipation to the outside. Suitable multimode resonators (microwave thermal cabinets), the volumes of which i) can be larger than several wavelengths, which is necessary for large samples. To ensure uniform heating of the leaves, the resonator can be equipped with a mode distributor (a metal moving device that continuously changes the field distribution) and a moving table surface, like a conveyor belt. Better results are achieved by microwaving single leaves, as opposed to bundles or bags of leaves.

According to the best embodiment of the invention, the microwave processing conditions include a frequency of approximately 900-2500 MHz, better - 915-2450 MHz, a power of approximately 600 W-300 kW, for kitchen-type resonators it is better 600-10008 W, and for industrial multi-mode resonators 2-75 kW, better, 5-50 kW. The heating time is, of course, within approximately at least 1s, and better 10s - 5 minutes. At a power of 800-1000W, the heating time is, of course, approximately 1-2.5 minutes when processing single leaves, as opposed to bundles or packages. For cha industrial multimode resonators, for example, 2-75kW, the heating time can be reduced to 5-60s, of course, 10-30s with, for example, bOkW for single leaves, as opposed to bundles or packages. Those skilled in the art will certainly appreciate that the optimum microwave field intensity can be determined for any resonators based on their volume, applied power and leaf moisture content. It is usually said that the use of higher powers requires less time for treating leaves with microwave irradiation. However, the conditions described above are not absolute and are given to explain this invention, experts will be able to determine acceptable microwave parameters. Microwave irradiation is better applied to leaves or ;" parts of it for a time sufficient to dry it effectively, without charring, so that it remains fit for human consumption. Microwave irradiation is also preferably applied to the leaf or part thereof for a time and at an intensity sufficient to reduce the moisture content to less than 2095, preferably -10965, by weight.

Figure 3 shows an embodiment of an industrial microwave resonator partially in perspective. In particular, Misgodgu’s 30kW microwave drying system 1 is shown, which includes a frame 2 of a moving trolley (the front end on the right side of the diagram is not shown), a microwave oven 3, 5 equipped with a conveyor, which in the middle includes four modular chambers of single-wall construction ( which can be made of aluminum and Z0O0OZNI14), each chamber has a size of 4800 mm in length, 2100 mm in width and 1200 mm in height and is equipped

Kk with four entrance doors, two on each side. The door is double locked to prevent accidental microwave exposure.

Figure 3 shows an automatic cutting device 5, which includes a plurality (for example, 12) of rotating blades 2 for separating the leaves 4 from the stem. The cutter can be a straight band approximately 85mm wide from below the center of the leaf, hand fed. Any suitable prevention device may be installed if desired

F) insertion of the operator's hands. Although Fig. 3 shows a device for separating the leaves from the stem, according to another embodiment of the invention, whole leaves can be used. Therefore, instead of a cutting device, there can be a tank for steam treatment, or a pair of rollers for squeezing moisture from the leaves. As can be seen from Fig., after separating the stem, the cut tobacco leaves 6 are fed by a belt conveyor 7 to the main microwave oven 3, which has four chambers. According to one embodiment of the invention, the system has a thermal cabinet with a length of approximately 1950 mm. The conveyor that moves the leaves into and within the cooler may have a series of, for example, six different speed polypropylene belts arranged to allow the cut stalks to fall from a pair of belts into a hopper below the belts (not shown). The belts will then carry the 65 cut leaves through one of two gangways located on each of the microwave containment chambers and then into a selected chamber where each leaf is exposed to microwave radiation in the manner described above in accordance with the invention. After that, the conveyor carries the leaves from the chamber through the exit opening, through the discharge chute of the thermal cabinet, and from it the conveyor carries them further into an acceptable tank for further processing.

To remove humidified air from the chambers and the thermal cabinet, the system may include an exhaust system including suitable fans to circulate the air (see moisture extraction holes, number 8 is indicated as representative in Fig.3). If desired, also, the temperature in the thermal cabinet can be controlled by an appropriately located convection heating device for air circulation, so that the inner part of the thermal cabinet outside the microwave chamber is at a constant temperature of preferably 70, for example, 71-822C during the transfer of leaves on the conveyor. In a mobile field system such as that of Fig. 3, electrical power can be provided by a pair of conventional diesel generators 9, 10. It is clear that the microwave drying system can also operate in a fixed location with power, if desired, from a conventional electrical source .

Each of the four chambers in the thermal cabinet Z receives microwave energy from the corresponding source Misgodgu 75 Mode! IM-75. Microwave energy enters each respective chamber from the distributor through two holes located on top of each chamber. A mode distributor is located below the openings in each chamber to help distribute the microwave energy. Each microwave power section is a partially independent rack that includes the necessary components to operate the 75 kW magnetron. Microwave power controls are located on the rack. Sections are designed for automatic continuous work in production conditions.

Each microwave power generator can be located in each chamber or at a distance from it.

However, at a distance of 15m, the transmission line losses reach approximately 295. Each power generator provides regulated microwave energy for production operations. Output power can be adjusted from

Up to approximately 75 kW at a frequency of 915 MHz, it is regulated by a solid-state control circuit with manual control by a handle on the panel or remote control by a control signal of 4-20 mA from the controller of processing. When the circuit changes the output power from O, the frequency spectrum begins to expand at levels below 5 kW.

The power generator for each chamber is essentially an industrial magnetron, operating directly from the supply of power current, which is controlled and protected by a functional circuit designed for automatic and manual adjustment. The electrical parameters of the generator are controlled by measuring devices on the control panel located on the door of the rack. Measurements include anode current, anode voltage, output power, glow current, electromagnetic flux, and reflected energy. The operation of the electromechanical functional lock is controlled by the signal lamps located on the control panel. Each microwave generator rack has a full-width door (3) to maximize component access. A built-in electromagnetic radiation shield surrounds the magnetron and attached microwave components. The door allows insertion of the magnetron and electromagnet. o

The system includes a circulator and a water charge inside the rack, which functions as an insulator to protect the magnetron in case of high energy reflection. The microwave energy generator uses water for cooling and forced air supply to cool the heat-emitting components. The magnetron and electromagnet are cooled by demineralized water from a closed system. A separate water source and heat exchanger can be used to cool the water in the system. A separate source of water also flows through a water-to-air heat exchanger inside the rack to cool the air inside. A high-pressure centrifugal blower provides cooling of the magnetron output and the cathode structure. Typical references and data for any microwave generator in the system are as follows: и? Input power U5kW, 440-480 MAS, C phase, bOHc

The output power is 75 kW at 915-10 MHz

Magnetron lamp STI, SMUM 75 1 -I Typical reference data for magnetron operation are as follows: 1 Voltage of alternating current of filament 11.48 av | Incandescent filament current 8BA

Voltage of the direct current of the anode 17"8 u Anode current BA - Coefficient of useful action 8090

In addition, in a conventional magnetron generator, the body can be made of carbon steel, and the external HV connection (MUK 975 waveguide) can be made on top of the rack in an acceptable place.

In a performance test, the microwave tobacco drying system, basically as described above, (F.) effectively removed more than 8095% of moisture from the leaves. In particular, on one tested sample, 7kg of leaves with an initial water content of 8595% and solids of 1595% were passed through the microwave chamber at a thickness of one sheet at a rate of 8Okg/hour, after which the leaves were weighed. The final mass was 2kg, or 3195 of the original. Therefore, taking into account the initial water content, 1.1kg remained in the leaf n, which corresponds to 18.595 of the original content.

As shown in Fig. 2, microwave treatment of yellow tobacco according to the invention gives a mostly dry golden-colored product. The data presented here show that such dried tobacco in non-fuel form has a dramatically reduced content of carcinogenic nitrosamines, in particular INN and NPB, compared to tobacco dried by the usual v5 method. It is also determined that concentrated forms of electromagnetic radiation (that is, concentrated as distinguished by a total exposure to sunlight or electric light within the visible spectrum) of a higher frequency and shorter wavelength than the microwave radiation described above can be used to achieve the main objective of the invention is to reduce or substantially eliminate STNA in a tobacco product when treated with such forms of energy within approximately the same time frame after harvest as defined above for the microwave embodiment, in other words, the same general and predominant methods as described above for microwave treatment can apply when using one or other energy sources, for example, tobacco is processed in approximately the same time frame after harvesting, leaves can be stripped of stems, squeezed between rollers and steamed before irradiation, etc.

However, while alternative energy sources were determined to significantly and adequately reduce or prevent 7/0 formation of STNA, no other embodiment investigated was as effective as drying the leaves by the detailed microwave method. Therefore, when using such alternative energy sources, it may be better to subject the irradiated tobacco leaves to further processing to complete the drying cycle, such as combining the irradiation operation with subsequent drying in a thermal cabinet or flipping.

In particular, it can be thought that any source of electromagnetic radiation and accelerated particles, such as /5 electrons, having energy higher than the microwave region within the normal electromagnetic spectrum, are effective for a relatively significant reduction, substantial elimination of STNA and/or prevention of it formation, when the uncured tobacco is in a state that contributes to the reduction of the content or delay in the formation of STNA. On the scale of the electromagnetic spectrum, where microwaves are defined as including forms of electromagnetic radiation with a frequency of 10 Hz or more and a wavelength of 3103 m, such energy sources include, without limitation, far infrared and infrared radiation with a frequency of approximately 10 12-1014 Hz and a wavelength of 3.1077 -3.10Um, ultraviolet radiation with a frequency of approximately 10 19-1018Gu and a wavelength of 3.108-3.10719m, soft X-ray or laser radiation, cathode rays (electron current from the cathode of a vacuum tube perpendicular to the surface), X-ray and gamma radiation, with with a characteristic frequency of 1021 Hz and the corresponding wavelength

It is clear to those skilled in the art that with higher doses of irradiation from the energy source, a shorter time of processing (o) the leaves is required to obtain the desired result. Of course, when using such high-frequency sources, the irradiation time is less than 1 minute, preferably less than 30s, and better 10s. When using the specified other method, the irradiation time 1s is preferred. However, as shown in the examples below, the exposure period «- zr It is possible, if desired, to adjust by distributing the irradiation dose in time. For example, 1OkGy of radiation can be applied instantaneously (as with the electron accelerator described below in Example 17) or distributed over a predetermined exposure time (as described in Example 19 for a closed gamma radiation chamber, where 1OkGy of radiation was distributed over time at an intensity of approximately 8OkGy / hour). When using high-frequency energy sources, irradiation is preferably used, which achieves at least 5090 IF) reduction of STNA compared to untreated samples. While the specific dose of radiation and the period M of exposure depend on the specific equipment used and the type of radiation source, specialists should understand that it is generally better to expose tobacco samples to radiation in the range of approximately 1-100 kGy, preferably approximately 5-50 kGy, and better 7 ,5-15 kGy.

As shown in the following examples, research was conducted on various samples of tobacco using " 70 examples of such additional sources of irradiation are accelerated electrons, a carbon dioxide laser, and gamma radiation. In each case, the non-cured irradiated tobacco samples showed significantly reduced or essentially absent STNA. :z" In a further embodiment of the invention, the processing of tobacco in its acceptable condition in a thermal cabinet with convection air circulation also demonstrated a decrease in the content of STNA, although with a deterioration in the quality of the leaves. In contrast to the usual drying chamber, which is not effective in reducing the content of STNA and deteriorates the quality of leaves, -1 heating in a thermal cabinet with convection air circulation at 38-260 °C for a period of time from 1 hour at a lower temperature to 5 minutes at a higher temperature is effective reduces the content or delays the formation of STNA 1 in tobacco when it is in the above-mentioned state favorable for this. Preferably, a thermal cabinet that combines thermal convection for air circulation and microwave irradiation can reduce heating time while improving leaf quality. For example, when using only a convection oven, the veins and where the stems do not dry completely during drying of the leaf plates, leading to overdrying and fragility of these plates. The combination of microwave processing with a convection oven with air circulation improves the quality of the leaves, making the dried product more uniform.

According to a further aspect of the invention, a method is proposed for reducing or essentially depriving a person or animal that smokes, chews or otherwise uses tobacco of STNA by providing a tobacco product for consumption that has a significantly reduced content or is essentially devoid of STNA. (F. Treatment of uncured tobacco with microwave or other irradiation is shown here to be effective in obtaining a tobacco product with an unexpectedly low nitrosamine content. The implementation of the method can be facilitated by layering and positioning the stem from the bottom 1/3-1/2 of the length of the tobacco leaf, especially in cases where in the stalk must be discarded, and the above-described dehumidification or steam treatment was not performed. When the stalks are removed in this way, the resulting microwave-treated tobacco leaves do not require the use of a thresher, since the unwanted part of the stalk has already been removed. As a result, the usual losses of tobacco product such as associated with threshing, reducing tobacco waste by approximately 10-30905.

The improved tobacco according to the invention can completely or partially replace conventionally dried tobacco in any tobacco product, including cigarettes, cigars, chewing tobacco, snuff and tobacco-containing chewing gum, tablets, tobacco flavors and food additives. According to the invention, a less harmful aftertaste is achieved for smoking, while maintaining good taste characteristics and providing a very good taste with a normal nicotine content. For chewing, sniffing, inhalation and food additives, tobacco according to the invention has a strong pleasant smell.

Next, the invention is illustrated by non-limiting examples.

Example 1 Smoked virginia tobacco was collected and the leaves were placed in a drying barn at approximately 38-432C to begin smoke drying. Samples 1-3 were collected from the barn after the leaves turned yellow, approximately 24-36 hours after collection. Sample 1 was a plate separated from the main vein and dried in a convection oven at about 4400-5002 for about an hour until the plate turned brown 70. Sample 2 was a yellow leaf transferred to a Soyavsiag Moade microwave oven!

MA-1572M (2450 OMHZ) and heated at the highest power (1000 W) while rotating for 2.5 minutes. Sample C was untreated yellow leaves for control. Samples 4 and 5 were left in the drying bar at an elevated temperature of approximately 822C, sample 4 was dried outside the rack, and sample 5 was dried inside the rack. The sample would be dried brown leaves after conventional smoke drying.

Each sample was analyzed for the content of INN, NPB, NAB and NAT. In this and the following examples, STNA means the sum of these 4 tobacco-specific nitrosamines. Samples were processed by extraction followed by conventional analysis for STNA (see, for example, Barton et al.

Tivvtse 1. Torasso-zresiis Miigozatipevz, Migatse, Miige apa AiKkaiidz" (Distribution of tobacco components in the tissue of tobacco leaves. 1. Tobacco-specific nitrosamines, nitrates, nitrites and alkaloids) 9. Adgis. Gosd Spet. M40, Mob, 19921 and separate STNA on the thermo-energy analyzer model 543 manufactured by Tepteadis

Ips, connected to a gas chromatograph Nemiay-Raskaga model 5890A. The results are presented in Table 1.

All data for each following table are presented in μg of nitrosamine per 1 g of sample. sch o - z o c "c)

Example 2 Smoke virgin tobacco was collected. Sample 7 represented freshly cut green leaves as a control. Sample 8 represented freshly cut green leaves that were treated with microwave irradiation in a multimode microwave resonator manufactured by Misgodgu oi GoivmiPe, Kepiysk, operating at Kk. 2450 Hz and 2.5 kW, for 20 seconds. Samples 9-12 were made from conventional smoke-cured brown tobacco. Sample 9 was molded cigarette tobacco, Sample 10 was loose ground cigarette tobacco, Samples 11-12 were the same as Samples 9 (cigarette) and 10 (loose), respectively, except that each was microwaved as sample 8. The content of STNA was analyzed in the same way as in example 1. The results are presented in table 2. in Lexington, Kentucky and analyzed for STNA content in the same way as in example 1.

Example 4 Smoked virginia tobacco was collected and the leaves were placed in a drying barn at approximately 38-432C to start smoke drying. After the leaves turned yellow, about 24-36 hours after collection, it was 7/0 transferred to the Soijiag Mode microwave oven! MA-1572M (2450MHz) was processed at the highest power (1000W) while rotating for 2.5 minutes. At the same time, the leaves were effectively dried, although they did not turn brown, but remained golden-yellow in color. It was crushed and made into cigarettes.

Samples 29-33 were taken from the batch marked Red with good taste, and samples 34-38 were taken from the batch marked Light Blue. Samples 39-42 were cigarettes purchased from a health food store under the brand name Maishga (Ategisap Zrigii). Samples 29-42 were analyzed for STNA content in the same manner as in Example 1.

The results are presented in Table 4. Example 5 Smoke virgin tobacco was collected and leaves were placed in a drying bar at approximately 38-432С to start smoke drying. Samples 43-44 were taken from the barn after the leaves had turned yellow, approximately "» 24-36 hours after collection, and were treated with microwave irradiation on the MisgoOgu multimode resonator described above at power bkW for approximately 20 and Zbs, respectively. Samples 43 and 44 were after microwave irradiation of dried, golden-yellow leaves. Samples 45-51 were made from brown-and-dried leaves subjected to conventional smoke drying. Sample 45 was a control. Samples 46 and 47 were sl-roasted in a preheated 205-2602C convection oven for approximately 1 and 3 minutes, respectively, and samples 48 and 49 were treated with microwave irradiation (915 MHz) using a waveguide (av) resonator of the MU/K-915 model, a large multimode thermal cabinet manufactured by MisgoOgu with a power of 0-75 kW at 7 50 5 OKkW for 10 and 40c, respectively. Samples 50 and 51 were cut (processed leaf tobacco) made from smoke-cured leaf tobacco. Sample 50 was processed by microwave irradiation according to -. using a waveguide resonator at a power of 5 kW for about 1.5 minutes, and sample 51 was baked in a convection oven preheated to 205-2602C for about 3 minutes. The samples were analyzed for the content of STNA in the same way as in example 1. The results are presented in Table 5. Shchi yu vo bo 50 - cut tobacco, waveguide, BOkW 4.22 4.91 0.99. 1012

Example b Smoked virginia tobacco was collected and the leaves were placed on a drying rack at approximately 38-432C to start smoke drying. Samples 52-55 were cigarettes made from yellow tobacco collected from the bar approximately 24-36 hours after collection and processed in the microwave oven described above

Soyasiag Mode! MA-1572M (2450MHz) at the highest power (1000W) for 2 minutes. Samples 61 and 62 for comparison were cigarettes made from leaves subjected to conventional smoke drying without microwave irradiation. Sample 56 was dried leaves, sample 57 was post-yellowing incompletely dried leaves, /o sample 58 was dried plates, and samples 59 and 60 were dried veins. The content of STNA was analyzed in the same way as in example 1. The results are presented in Table 6.

And so on

Example 7 Smoked virgin tobacco was harvested, samples 63 and 66 were uncured freshly harvested green tobacco, although aged for a week prior to measurement of STNA content under air drying conditions. The rest of the leaves were placed in a drying barn at approximately 38-432C to start smoke drying. Sample 68 was taken from "-- from the barn after the leaves turned yellow, approximately 24-36 hours after collection, and was treated with microwave irradiation on the Uahedcide multimode resonator described above at a power of 25 kW for approximately 40 seconds. Samples 64/65 and 67/70 (processed leaf tobacco, or cut tobacco) demonstrate the effect of the method according to the invention, where the dried tobacco is rehydrated and then subjected to microwave irradiation. Samples 64 and 65 were leaf samples subjected to conventional smoke drying, however, sample 64 was rehydrated by spraying with water for 5-10s. The leaves absorbed a significant amount of moisture, each of which was then treated with microwave irradiation on the above-described multi-mode resonator UUamedcide at a power of 25 kW, approximately 4Os. Samples 67 and 70 were processed leaf tobacco samples made from dried leaves. Sample 64 was rehydrated by adding water until it was significantly absorbed and then treated with microwave irradiation under the same conditions as for sample 64. Sample 70 was not treated with microwave irradiation. Samples 69, 71 and 72 were additionally dried leaf samples from c for control. The content of STNA was analyzed in the same way as in example 1. The results are presented in Table 7. :» v - s o t z

Example 8 Smoked virgin tobacco was harvested and the leaves were placed in a drying barn at about 38-432C (F) to start the smoke drying. Sample 73 was leaves taken from the barn after turning yellow, about 24-36 hours after picking and treated with microwave irradiation on Soidziag Moae!

MA-1572M at the highest power for 2 minutes. Samples 74-76 were subjected to conventional smoke drying. because Sample 74 was a dried control. Samples 75 and 76 were rehydrated as in Example 7 (Sample 64) and then each treated with microwave irradiation (2450MHz) on MisgoOgu at bkW for 20s (Sample 75) and 40s (Sample 76), respectively. Samples 77-79 were processed leaf tobacco made from smoke-cured tobacco leaves. Sample 77 was a control, and samples 78 and 79 were rehydrated as in example 7 (sample 67), samples 78 and 79 were treated with microwave irradiation on MisgoOg for about 20s, b5 each, sample 78 remained on the tray of the thermal cabinet, and sample 79 was lifted by several cm by placing the sheet sample on a Styrofoam cup, which gave more uniform heating. The samples were analyzed for the content of STNA in the same way as in example 1. The results are presented in Table 8; at

Example 9 Samples 80 and 81 were purchased over-the-counter chewing tobacco. Sample 80 was /5 Hontrolny, and sample 81 was treated with microwave irradiation on Soyidvziag ModeI MA-1572M at the highest power for 1-2 minutes. Samples 82 and 83 were over-the-counter Skoal snuff. Sample 82 was a control, and sample 83 was treated with microwave irradiation as sample 81. The samples were analyzed for STNA content in the same way as in example 1. The results are presented in Table 9 2 sia o

Example 10 For experiments in which STNAs accumulated over time even after yellow tobacco was treated with microwave irradiation according to the invention, additional samples (marked - A) of the cigarettes tested in Example 4, samples 29, 35 and 39 (control) were again analyzed for the content of STNA more than 7 months after the first measurement of the content of STNA, which is described in example 4. The results are presented in Table 10. - calculated

Example 11 Smoked virginia tobacco was collected and the leaves were placed in a drying barn at approximately 38-432C to begin smoke drying. After it turned yellow, about 24-36 hours after collection, it was treated with microwave irradiation on a ZoYidziag ModeI MA-1572M at the highest power of 50 for 2-2.5 minutes. The color of each leaf was golden yellow, the leaves were well dried. Some of the samples labeled C c hereafter as "ground" were further ground into a powdery substance suitable, for example, as a chewing gum, tablet, or flavoring agent. More than a month after microwave treatment, the samples were analyzed for STNA in the same way as in example 1. The results are presented in table 11. - slo uyu z oyu o r. 101 - leaves 0.00130.0539 «0.0019 |«0.001610.0587

Example 12 Smoked virginia tobacco was collected and the leaves placed in a drying barn at approximately 38-4322; to start smoke drying. Samples 104 and 105 were leaf samples subjected to conventional smoke drying without microwave irradiation. Sample 104 was dried veins and sample 105 was dried plates. Sample 106 was yellow tobacco taken from the barn about 24-36 hours after collection and processed in the Soiidwziag Mode microwave oven described above! MA-1572M (2450 MHz) at the highest 70 power (1000 W) for 2-2.5 minutes. The color of each leaf was golden yellow, the leaves were well dried. Some of the dried leaves were further processed in the usual way to form a tobacco extract, which is designated as sample 107. The STNA content of samples 104-107 was analyzed in the same way as in example 1.

The results are presented in Table 12. and m

Example 13 Smoked virginia tobacco was collected and the leaves placed in a drying barn at approximately 338-432; to start smoke drying. Samples 108 and 109 were leaf samples subjected to conventional smoke drying. Sample 108 was dried plates and sample 109 was dried veins. Samples 110 and 111 were mixed with YellowM tobacco, which was taken from the barn approximately 24-36 hours after collection, and processed in a convection oven Zpagr Sagoise! Sopmesiop/Mishomaghe Mode! кК-9Н848В. Sample 110 was rapidly heated to approximately 15022°C for 5-10 minutes. Sample 110 was heated more slowly at a lower temperature starting at 382C and increasing to about 602C after more than 10 minutes for a total heating time of more than 20 minutes. Contents

STNA in samples 108-111 was analyzed in the same way as in example 1. The results are presented in Table 13.

Although heating in a convection oven led to a decrease in the content of STNA, the quality of tobacco was worse than that obtained by treatment with microwave irradiation according to the best examples of the invention. In addition, longer processing time is required than when processing with microwave irradiation or other forms of high-frequency radiation. In particular, convection heating is unable to fix the desired golden-yellow color, and the plates tend to dry out and therefore become brittle, while the vein and stem dry incompletely. In contrast, according to the best embodiments of the invention, microwave-treated leaves were effectively dried and remained golden-yellow after treatment

Color, soft and capable of further processing, especially into cigarettes. In the samples produced in the convection-I thermal cabinet, the dried plate had a tendency to crumble into dust and small tobacco particles.

Example 14 Kentucky Barley tobacco was harvested and treated leaves in the manner described below after the beginning of 1 its conversion to yellow, approximately 24-48 hours after harvest. Samples 112-117 were leaves from this batch processed as described below. Sample 112 was microwaved under approximately the same conditions as sample 106 from Example 12. The leaves were golden yellow in color and well dried. Samples 113, where 114 and 117 were heated in the same convection oven described in example 13, sample 113 was heated under approximately the same conditions as sample 110, sample 114 was heated under approximately the same conditions as sample 111, and sample 117 were heated for approximately 20 minutes at approximately 1772. The quality of samples 113, 114 and 117 was similar to the quality of samples 110, 111 from example 13. Samples 115 and 116 were heated in the ZNnagr Sagoisei thermal cabinet described in example 13! dv Sopmesiiop/Misgomamje with a combined microwave (3095)/convection (15022) treatment until the leaves have dried effectively to a golden yellow color. The content of STNA in samples 112-117 was analyzed in the same way as in iF) example 1. The results are presented in table 14. ime) in 5

Example 15 Smoked virgin tobacco was harvested and the leaves were placed in a drying barn at about 38-432C7 to initiate smoke drying, leaves taken from the barn after yellowing had begun, and then rapidly microwaved in a conventional kitchen-type oven for about 2-2.5 minutes to effectively dry the leaves and acquire a golden-yellow color without darkening or burning. Samples 121-123 were samples of strong Kentucky tobacco harvested and processed after the onset of yellowing as described below. Sample 121 was placed in a conventional steam-heated dryer commonly used in the tobacco industry at about 932°C until the leaves turned brown and somewhat 7/0 dried. Sample 122 was microwaved in the Soiaviag Modded MA-1572M (2450 MHz) described above at highest power for approximately 2 minutes, rehydrated with water, and transferred to a steam-heated dryer until the leaves were lightly browned, which is believed to improve flavor. Sample 123 was treated similarly to sample 122 except that it was microwaved for 1 minute and was not rehydrated before being transferred to a steam-heated dryer. The content of STNA in samples 118-123 was analyzed in the same way as in example 1. The results are presented in Table 15.

Example 16 North Carolina Barley tobacco was harvested and treated leaves as described below after (o) beginning to turn yellow, approximately 2-3 days after harvest Sample 118 was leaves treated in the above described Soyaziag microwave oven at highest power for 2 minutes

After the acquisition of well-dried leaves of a golden-yellow color, the content of STNA in the sample was analyzed in the same way as in example 1. The results are presented in Table 16.

Example 17 This example demonstrates the effectiveness of electron beam irradiation to reduce - the content of, or essentially prevent the formation of STNA in samples of yellow tobacco. North Carolina barley tobacco was collected, samples 119-122 were dried in the usual way by hanging the leaves in the air until they were dry and brown. Sample 119 was not processed as a control. Samples 120 and 121 were irradiated with an electron beam on the Supatiyop electron accelerator manufactured by Kadiayop Bupatisv, Ips. oh Eddezhmos,

MM,, within 10 kGy. Sample 122 was subjected to microwave irradiation in the above-described Soiasiag microwave oven at the highest power for 2 minutes. Sample 123 was taken from the top of a strong leaf after the beginning of its yellowing. Sample 124 was part of a stem taken from the same plant as sample 123, but it was still somewhat greenish. Samples 125 and 126 were solid strong leaves in the yellow stage. Each of the samples 123-126 was irradiated with an electron beam on the electron accelerator described above in the same way and with the same exposure as the samples 120 and 121 described above. The content of STNA in samples 119-126

They were analyzed in the same way as in example 1. The results are presented in table 17.

Although the above data show the effectiveness of electron beam irradiation to reduce the content, 60 or essentially prevent the formation of STNA in the tested samples of yellow tobacco leaves, the drying of the leaves is not as effective as when the leaves in a similar condition after harvest are exposed to microwave irradiation as described in other examples of this application. Therefore, the industrial application of the electron beam irradiation method may require an additional drying operation by passing the irradiated leaves through a conventional thermal cabinet to facilitate drying. for Example 18 This example demonstrates that irradiation with high-energy laser beams also gives a low content of STNA according to the purpose of the invention. The leaves of yellow virginia tobacco were irradiated with a carbon dioxide laser produced by I Ihag Sogr., model I X-205R 2-3 days after harvesting. Momazsap-control was used with the ziregriize E program, which determines the speed of processing in samples per second. The ETO installation was used, which distributes 10 samples per second. 8 subsamples of leaves from T-1 to T-8 were irradiated according to the following protocol:

E10 -2W E10O - 4W

T-1-1 pass on each side / T-5 - 1 pass on each side 7-2 - 2 passes on each side 1-6 - 2 passes on each side 76 T-3 - Z passes on each side 1-7 - Z passes on each side tT-4 - 4 passes on each side 1-8 - 4 passes on each side

At 2W, approximately 120mJ of energy was emitted per scan or pass, and at 2W, approximately 240mJ was emitted per scan or pass.

Sub-samples from T-1 to T-4 were mixed and combined to form leaf sample 127, in which the content of STNA was analyzed in the same way as in example 1. Sub-samples from T-5 to T-8 were also mixed and combined to form leaf sample 128, in which the content of STNA was analyzed similarly. The results are presented in Table 18.

As with the samples described in example 17, samples irradiated with a CO laser did not give effective drying of the leaves, although the content of STNA in the leaves was low, and therefore required an additional drying operation to accelerate it. with

In addition, after laser irradiation, but before the determination of STNA, 6 of the 8 subsamples turned slightly brown with no noticeable effect on the STNA content.

Example 19 This example demonstrates the effectiveness of gamma irradiation in preventing the formation of STNA in yellow tobacco samples. Smoke virgin tobacco is taken after the leaves turn yellow, approximately 24-36 hours after picking. Each of the samples 129-132 was taken from the lamellar part of a yellow leaf and subjected to gamma irradiation in a closed chamber at a dose of 1OkGy at an intensity of 8kGy/hour with a total exposure time of approximately 75 minutes. The irradiated samples were analyzed in the same way as in example 1. The results are presented in Table 19.

Those skilled in the art should understand that various changes and modifications can be made in the best embodiments without departing from the scope of the invention. Therefore, the given description serves only as an illustration and does not limit the invention.

Claims (42)

The formula of the invention - I sl 1. A method of reducing the content or preventing the formation of nitrosamines in harvested tobacco plants, which includes stage (i) with the operations of (a) separating the stem from the tobacco leaves, (b) pressing the tobacco leaves for (а) removing excess moisture or (c) treating the tobacco leaves with steam and step (ii) with the microwave operation 50 irradiating at least a part of the plant while the aforementioned part is not dried and is in a receptive state in order to have a reduced content of nitrosamines, or to delay their formation, - for a sufficient time to reduce the content or significantly prevent the formation of at least one nitrosamine of time, and the indicated operation of microwave irradiation is carried out on the tobacco leaf or its parts after the beginning of yellowing of the leaves and before significant accumulation of nitrosamines specific for tobacco in it, and the indicated tobacco leaves or its parts are placed in a layer thickness in one sheet without stacking or packing leaves. o 2. The method according to claim 1, which differs in that stage (i) includes the operation of (b) pressing the tobacco leaves to remove excess moisture or (c) processing the tobacco leaves with steam, if the tobacco leaves include stems. 3. A method of significantly preventing the formation of nitrosamines in harvested tobacco plants, which includes the operation of irradiating at least part of the plant with concentrated radiation, the frequency of which is higher than the frequency of the microwave region of the electromagnetic spectrum, while the above-mentioned part is not dried, yellow, and is in a state susceptible to stopping the formation nitrosamines for a time sufficient to substantially prevent the formation of at least one nitrosamine. 4. The method according to claim 3, which differs in that the specified irradiation operation is carried out before the significant loss of 65 integrity of leaf cells. 5. The method according to claim 3, which differs in that the tobacco is smoke tobacco, and the specified irradiation operation is carried out during a period of approximately 24-72 hours after harvesting. 6. The method according to claim 3, which differs in that the specified irradiation operation is applied to the plant for approximately 1 s at a predetermined power. 7. The method according to claim 3, which differs in that it also includes drying the portion after the irradiation operation. 8. The method according to item C, which differs in that the specified irradiation operation is carried out with a laser beam. 9. The method according to item C, which differs in that the specified operation of irradiation with an electron beam is carried out using an electron accelerator. 70 10. The method according to item C, which differs in that the specified irradiation operation is carried out with gamma radiation. 11. The method according to claim 3, which is characterized by the fact that the specified irradiation operation is performed on a tobacco leaf or its part until a substantial accumulation of at least tobacco-specific nitrosamines in the leaf or its part. 12. The method according to claim 11, which differs in that the specified irradiation operation is carried out on a tobacco leaf, which is placed in a layer with a thickness of one sheet without stacking or packing the leaves. 13. The method according to claim 12, which is characterized by the fact that before the indicated operation of irradiation, the operation of (a) separation of the stem from tobacco leaves, (b) pressing of tobacco leaves to remove excess moisture or (c) processing of tobacco leaves with steam is performed. 14. A tobacco product having a reduced content of at least one tobacco-specific nitrosamine and produced by a method that includes the operation of treating the tobacco while the tobacco is uncured, yellow, and susceptible to delaying the formation of said at least one tobacco-specific nitrosamine by concentrated irradiation, the frequency of which higher than the frequency of the microwave region of the electromagnetic spectrum. with 15. The method of producing a tobacco product, which includes the operation of irradiating tobacco leaves with a concentrated form of radiation, the frequency of which is higher than the frequency of the microwave region i) of the electromagnetic spectrum, while the specified leaves are not dried and are in a receptive state in order to have a reduced content of nitrosamines or to delay their formation, during a sufficient time to reduce the content or significantly prevent the formation of at least one nitrosamine in the leaf, and the creation of the specified tobacco product from irradiated leaves, and the tobacco product is selected from the group consisting of cigarettes, cigars, chewing tobacco, snuff tobacco, tobacco-containing chewing gum and tablets. with 16. The method according to claim 15, which differs in that the specified irradiation operation is performed after the beginning of yellowing of the leaves and before significant accumulation of nitrosamines specific for tobacco in the leaves. 17. A tobacco product characterized by the fact that it contains dried non-green or yellow smoky Scheo, virgin tobacco, suitable for human consumption, substantially free of organic liquids used for the extraction of dispersed organic materials, and having a total content of M of '-nitrosonornicotine, 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone, M'-nitrosoanatabine, and M'-nitrosoanabasine, which is less than about 0.2 µg/g. 18. A tobacco product characterized by the fact that it contains dried non-green or yellow tobacco "suitable for human consumption, substantially free of organic liquids used for the extraction of (7-3) from dispersed organic materials, and having in common /M'-nitrosonornicotine, . 4-(M-nitrosomethylamino)-1-(3-pyridyl)-butanone, M'-nitrosoanatabine and M'-nitrosoanabazine, which is 0.05 u? µg/g or less, wherein said dried non-green or yellow tobacco is selected from the group consisting of smoked virginia and barley varieties. 19. A tobacco product, characterized by the fact that it contains dried non-green or yellow tobacco, -I suitable for human consumption, in leaf form and having a common content of M'-nitrosonornicotine, 4-(M-nitrosomethylamino)-1-(Z- pyridyl)-1-butanone, M'-nitrosoanatabine and M'-nitrosoanabasine, which is about 0.05 μg/g or less, and said dried non-green or yellow tobacco is selected from the group consisting of varieties of smoke virginia and barley. 20. A tobacco product, characterized in that it contains dried non-green or yellow virgin de smoke tobacco, suitable for human consumption, in leaf form and having in common as M'-nitrosonornicotine, 4-(M-nitrosomethylamino)-1-( of 3-pyridyl)-1-butanone, M'-nitrosoanatabine and M'-nitrosoanabase, which is less than 0.2 μg/g. 21. A tobacco product characterized by the fact that it contains dried non-green or yellow tobacco, suitable for human consumption, essentially free of organic liquids used for the extraction of dispersed organic materials, and having a common content of M'-nitrosonornicotine, F) 4 -(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone, M'-nitrosoanatabine and M'-nitrosoanabasine, which is less than 0.2 µg/g, said dried non-green or yellow tobacco selected from the group consisting of the varieties of smokey United States virginia and United States barley. 60 22. A tobacco product characterized by the fact that it contains dried non-green or yellow tobacco, suitable for human consumption, in leaf form and having a common content of M'-nitrosonornicotine, 4-(M-nitrosomethylamino)-1-(3-pyridyl) -1-butanone, M'-nitrosoanatabine and M'-nitrosoanabasine, which is less than 0.2 mcg/g, said dried ungreen or yellow tobacco being selected from the group consisting of United States Virginia smoke and United States barley . 65 23. A tobacco product, characterized in that it contains dried non-green or yellow tobacco, suitable for human consumption, substantially free of organic liquids used to extract dispersed organic materials, and containing 4-(M-nitrosomethylamino)-1 -(3-pyridyl)-1-butanone, which is 0.002 µg/g or less. 24. A tobacco product, which is characterized by the fact that it contains dried non-green or yellow tobacco, suitable for human consumption, in leaf form and has a content of 4(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone, which is 0.002 µg/g or less. 25. The tobacco product according to claims 23 or 24, characterized in that said content of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone is 0.001 μg/g or less. 26. A tobacco product according to any one of claims 18, 19, 21, 22, 23, 24 and 25, characterized in that said 7/0 dried non-green or yellow tobacco is a smoke virginia variety. 27. A tobacco product according to any one of claims 18, 19, 21, 22, 23, 24 and 25, characterized in that said dried non-green or yellow tobacco is a variety of barley. 28. A tobacco product according to any one of claims 17, 20, 21 and 22, characterized in that said total content is 0.15 µg/g or less. 29. The tobacco product of claim 28, wherein said total content is 0.1 µg/g or less. 30. A tobacco product according to any one of claims 17-29, characterized in that said tobacco suitable for human consumption is dried yellow tobacco. 31. A tobacco product according to any one of claims 17-30, characterized in that it is a product selected from the group consisting of cigarettes, cigars, chewing tobacco, snuff, tobacco chewing gum and tablets. 32. A tobacco product containing dried non-green or yellow tobacco suitable for human consumption, the content of which is at least one tobacco-specific nitrosamine selected from the group consisting of M'-nitrosonornicotine, 4-(M-nitrosomethylamino)-1- of (3-pyridyl)-1-butanone, M'-nitrosoanatabine and s M'-nitrosoanabasine, about 7595 by weight less than the content of at least one specific tobacco-specific nitrosamine in dried brown tobacco obtained from the same harvest, with from which dried non-green or yellow tobacco has been produced, but which has been dried without carrying out an operation designed to reduce the content of at least one tobacco-specific nitrosamine. 33. The tobacco product according to claim 32, characterized in that said content is approximately 9095% by weight less than the content of said dried brown tobacco. 34. The tobacco product according to claim 33, which is characterized in that said content is about 9595 by weight less than the content of said dried brown tobacco. at 35. The tobacco product according to claim 34, which is selected from the group consisting of cigarettes, cigars, chewing tobacco, snuff, tobacco chewing gum and tablets. at 36. A method of substantially preventing the formation of nitrosamines in harvested tobacco plants, which includes drying at least a portion of the plants, when said portion is undried, yellow, and in a state susceptible to stopping the formation of nitrosamines, by convection of circulating air at a temperature of from about 382 to at about 260°C for a time sufficient to substantially prevent the formation of at least one nitrosamine. " 37. The method according to claim 36, which is characterized by the fact that said drying by means of convection of circulating -/-pka) with air in the tobacco leaf or its part is carried out before significant accumulation of nitrosamines in the leaf. and 38. The method according to claim 36, which is characterized by the fact that said drying with the help of convection of circulating "" air is carried out until a significant loss of cellular integrity of the plant. 39. The method according to claim 36, wherein said tobacco is Virginia smoke tobacco and said drying by means of circulating air convection is carried out within about 24 to 72 hours after harvesting. 40. A method of significantly preventing the formation of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone in the collected tobacco plants, which includes the operation of drying at least part of the plants, when the said part is undried, yellow, and is in a condition favorable to stop the formation of 500 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone by convection of circulating air at a temperature of from about 382 to about 260°C for a time sufficient to significant prevention - and the formation of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone. 41. The method according to claim 40, characterized in that said tobacco is Virginia smoke tobacco, and in that said drying with the help of circulating air convection is carried out between about 24 and 72 hours after harvesting. 42. The method according to claim 40, which is characterized by the fact that the mentioned part of the tobacco plant after the mentioned drying with the help of convection of circulating air has a content of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone, which is at least 7595 less than the content of 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone in dried brown tobacco obtained from the same crop of tobacco, but which was dried without a stage intended to reduce the content of the mentioned 4-(M-nitrosomethylamino)-1-(3-pyridyl)-1-butanone. b5