CN1272768A - Method of treating tobacco to reduce nitrosamine content, and products produced thereby - 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 tocacco. In preferred embodiments, the resultant tobacco products are dried, golden-yellow leaves having almost negligible amounts of the known carcinogens NNN and NNK, in comparison to conventionally cured tobacco.

Description

Handle the method for tobacco to reduce nitrosamine content and the product that makes thus

Invention field

The present invention relates to a kind ofly handle tobacco with content that reduces the harmful nitrosamine in the tobacco of being everlasting, find or the method that prevents its generation.The invention still further relates to the low tobacco product of content of nitrosamines.

The mutual reference of related application

The application is that the sequence number of on June 20th, 1997 application is the application that continues of 08/879905 application, the latter is the application that continues of No. 08/757104 application of application on December 2nd, 1996, the latter is again the application that continues of application on October 30th, 1996, existing resigned No. 08/739942 application, the latter is the application that continues of application on September 23rd, 1996, existing resigned No. 08/725691 application, and the latter is the application that continues of No. 08/671718 application of application on June 28th, 1996.The application and above-mentioned application except No. 08/671718 application of application on June 28th, 1996, require to enjoy the priority of No. 60/023205 provisional application of applying on August 5th, 1996.

Background of invention

Someone once described and utilized the microwave energy drying farm products.No. 4430806 patents of US of authorizing Hopkins have been described and have been utilized microwave energy slaking (cure) tobacco.In US 4898189, Wochnowski has instructed with microwave and has handled green tobacco, thereby the control moisture is so that storage or transportation.US3699976 has described with microwave energy and has killed the insect of invading and harassing tobacco.In addition, disclosed with inert organic liquid dipping tobacco so that extract the technology (US 4821747) of the organic substance of expansion by irrigating medium, wherein, mixture is exposed to microwave energy.In another embodiment, disclose with the dry mechanism (US 4874000) of microwave energy as the tobacco-containing material of extruding.In US3773055, the cigarette that Stungis discloses with microwave drying and launched to make with wet tobacco.

Use filter tip when in the past, mainly being included in smoking for the effort that reduces tar and harmful carcinogenic nitrosamine.In addition, once attempted to adopt additive to stop harmful carcinogenic effect in the tobacco.These effort all fail aspect the tumor incidence relevant with smoking reducing.The known green tobacco of newly tapping does not in fact contain the nitrosamine carcinogenic substance.For example referring to, people's such as Wiernik " influence that air-slake is formed tobacco chemistry ", the latest developments of tobacco science, 21 volumes, 39 pages and back page or leaf, the 49th tobacco chemistry man research association symposium procceedings (SymposiumProceedings 49th Meeting Tobacco Chemists ' ResearchConference), 24-27 day September nineteen ninety-five, Lexington, Kentucky (they are " people such as Wiernik " for following title).But the tobacco after the known slaking contains multiple nitrosamine, comprises harmful carcinogenic substance N '-nitrosonornicotine (NNN) and 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone (NNK).Widely acceptedly be that these nitrosamine are after results, form in the maturation process process, and are such as further described herein.Regrettably, the green tobacco of newly tapping is unsuitable for inhaling or otherwise consumption.

1993 and 1994, people such as Burton have carried out some tests in Kentucky State university with regard to tobacco-distinctive nitrosamine (TSNA), be reported in summary " by improving nitrite-nitrogen and tobacco the N '-distinctive nitrosamine in the baking temperature reduction air-slake tobacco ", agronomy and Plant Pathology joint conference, CORESTA, Oxford 1995.People's such as Burton report is pointed out, in air slaked each stage, comprises the yellow later stage (end of yellowing) (EOY), EOY+3, and EOY+5 etc. with the drying tobacco 24 hours of results, have certain reduction to content of nitrosamines under 71 ℃.Also have the freeze drying of some sample and the list of references of microwave, but do not have detailed content or conclusion.The applicant confirms that the effect of microwave is unsuccessful in the real work of being undertaken by the people such as Burton of Kentucky State university according to this summary.Some aspect of people 1993-94 such as Burton research is reported in people supra such as Wiernik, and 54-57 page or leaf, exercise question are " improved air-slake ".The tobacco leaf sample that people's such as Wiernik article hypothesis will be taken from air slaked different phase stands rapid draing 24 hours under 70 ℃, can remove excessive moisture, reduces microbial growth; Like this, the accumulation of nitrite and tobacco-distinctive nitrosamine (TSNA) just can be avoided.In 56 pages Table II, people such as Wiernik have quoted people such as some Burton to the blade of KY160 and KY171 sample and the summary data of nitrite on the middle arteries and veins and TSNA content.Freeze drying and rapid draing test for data have, but do not mention the microwave sample.Propose in the article to draw a conclusion:

Thus research can be reached a conclusion, and can reduce content of nitrite in blade and the middle arteries and veins and the accumulation of TSNA for after tobacco leaf loses its cell integrality dark tobacco heating (70 ℃).This stage at maturing process has been reduced the activity of microorganism with the rapid drying of tobacco leaf, and this activity is to take place at room temperature the slow maturing process.But must add one, such processing has reduced the quality of tobacco leaf.

The same, see 56 pages.The example of traditional slaking of Polish Skroniowski tobacco as two step slaking methods also discussed in people's such as Weirnik article.Claim in the article that tobacco, is heated to 65 ℃ with tobacco and keeps two days so that the slaking offal at first through air-slake when blade is yellow or brown.The tobacco that this method makes is analyzed, and analysis result shows that the content of nitrite and TSNA is all lower, promptly is lower than 10 microgram/grams and 0.6-2.1 microgram/gram respectively.People's reasonings such as Weirnik think that these results can be interpreted as since rapidly heating make the bacterium can not further growth.But people such as Weirnik also point out, low nitrite and TSNA content are lower than 15 micrograms/gram nitrite and 0.2 microgram/gram TSNA, obtain through air slaked tobacco in Poland.

Summary of the invention

An object of the present invention is to eliminate basically or reduce nitrosamine to be inhaled or the tobacco of otherwise consumption in content.

Another object of the present invention be reduce tobacco product comprise cigarette, cigar, chewing tobacco, snuff and contain the chewing gum of tobacco and lozenge in potential carcinogenic substance.

Another object of the present invention is to eliminate basically or obviously reduce the distinctive nitrosamine of tobacco, comprises N '-nitrosonornicotine (NNN), 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone (NNK), N '-nitroso anatabine (NAT) and the amount of N '-nitroso anabasine (NAB) in these tobacco products.

Another object of the present invention is the tobacco that the suitable time after results is handled not slaking, can adverse effect not arranged to the consumption performance of tobacco so that suppress maturing process.

Another object of the present invention is to reduce the content of the tobacco-specific nitrosamine in the tobacco of abundant slaking.

A further object of the invention is to reduce the distinctive nitrosamine of tobacco, particularly NNN and NNK and in smoking, consumption or otherwise absorb the content of metabolin in the person of certain form tobacco, method provide a kind of be suitable for human consumption, reduced the tobacco product of the distinctive nitrosamine amount of tobacco basically, thereby reduce the carcinogenic possibility of this product.Preferably, tobacco product is cigarette, cigar, chewing tobacco or chewing gum or the lozenge that contains tobacco.

Above-mentioned and other purposes of the present invention and advantage can reduce by the amount of nitrosamine in will the tobacco of results or prevent that it from forming reaches, and comprise

At least a portion to tobacco is carried out the microwave radiation, described part is without slaking and be in the state that is easy to reduce the amount of nitrosamine or suppresses nitrosamine formation, and radiated time is to be enough to reduce the amount of at least a nitrosamine or to prevent the time that at least a nitrosamine forms basically.

Preferably, in the methods of the invention, the step of tobacco leaf or its part being carried out the microwave radiation is to carry out after blade begins jaundice and before the distinctive nitrosamine of tobacco accumulates in blade in a large number.Also preferably carry out the microwave radiation before the lost cell integrality basically in the methods of the invention at tobacco leaf.

In another preferred embodiment of this method, tobacco is a flue-cured tobacco, and microwave irradiation step is carried out within about 72 hours at about 24-after the results, in addition more preferably after results about 24-carry out in about 36 hours.

In another embodiment of this method, the tobacco of results was remaining under the condition that is higher than room temperature under the environment of a control before standing microwave irradiation step.

The preferred aspect of this method comprises, before the tobacco leaf that preferably has offal stands the microwave radiation, tobacco leaf is carried out mechanical expression, from wherein squeezing out excessive moisture, thereby guarantees that the drying of carrying out with microwave device is more even.This step can be carried out easily, promptly makes it by the suitable rotational circle tubular roller in a pair of gap before tobacco leaf enters microwave office.

In another embodiment preferred of the present invention, under a predetermined electric power level, the frequency of the microwave radiation that tobacco leaf is carried out is the about 2500MHz of about 900-, and radiated time is at least about 1 second, preferred about 10 seconds to about 5 minutes.Used power level has determined tobacco leaf to stand the time length of microwave radiation usually, its scope can be about 600 to about 1000 watts when using common kitchen type micro-wave oven, to industry, multimode radio-frequency generator (applicator), then high to hundreds of or more kilowatts.For designing the radio-frequency generator of handling single tobacco leaf, used power is preferably about 75 kilowatts of about 2-, and more preferably from about 5-is about 50 kilowatts, can carry out fastish processing.

The present invention also preferably should be enough to effectively drying tobacco not made its charing to the time that tobacco leaf or its part are carried out the microwave radiation, thus suitable people's consumption.

The present invention also attempts to make tobacco leaf to stand the microwave radiation to prevent the distinctive nitrosamine of at least a tobacco, as the normal accumulation of N '-nitrosonornicotine, 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone, N '-nitroso anatabine and N '-nitroso anabasine.

The wideest form of the present invention also comprises such tobacco articles, and it comprises the content non-green tobacco lower than the tobacco of conventional slaking that is suitable for people's consumption and the distinctive nitrosamine of at least a tobacco.

In preferred embodiments, the content of the TSNA of non-green tobacco goods (NNN, NNK, NAB and NAT) is lower than 0.2 μ g/g, more preferably less than about 0.15 μ g/g, with in addition more preferably less than about 0.1 μ g/g, the content of NNN is lower than about 0.15 μ g/g, more preferably less than about 0.10 μ g/g, even more preferably less than about 0.05 μ g/g, the content of NNK is lower than about 0.002 μ g/g, more preferably less than about 0.001 μ g/g with even more preferably less than about 0.0005 μ g/g.

The invention still further relates to such tobacco product, it comprises the dry yellow tobacco that is suitable for people's consumption, and the amount of the distinctive nitrosamine of at least a tobacco is lower than the tobacco of conventional slaking.In preferred embodiments, content, NNN content and the NNK content of the TSNA of yellow tobacco product (NNN, NNK, NAB and NAT) are in above-mentioned preferred range.

In another embodiment, non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for people's consumption, the content of TSNA (NNN, NNK, NAB and NAT) is about 25wt% of the content of this TSNA in the green tobacco crop of the fresh results of this goods of preparation.The amount of the TSNA of more preferably non-green or yellow tobacco product is about 10wt% of the content of this TSNA in the tobacco crop of the fresh results of this goods of preparation, 5wt% more preferably from about, most preferably substantially near (as at height in the scope of a few percent by weight).Also preferred non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for people's consumption, be selected from NNN, NNK, the amount of at least a TSNA of NAB and NAT is about 25wt% of the content of corresponding TSNA in the tobacco crop of the fresh results of this goods of preparation, preferred about 10wt%, 5wt% more preferably from about, most preferably substantially near (as at height in the scope of a few percent by weight).

In other embodiments of the present invention, non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for people's consumption, TSNA (NNN, NNK, NAB and NAT) content than this TSNA with product same type of the present invention, by the preparation of identical tobacco crop but no microwave radiation or other for the technology that reduces TSNA content and design under content in the tobacco product for preparing of slaking hang down at least about 75wt%, preferably at least about 90wt%, more preferably at least about 95wt%, most preferably at least about 99wt%.Also preferred non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for people's consumption, it is selected from NNN, NNK, the content of at least a TSNA of NAB and NAT than corresponding TSNA by with product same type of the present invention, by identical tobacco crop but no microwave radiation or other for the technology that reduces TSNA content and design under content in the tobacco product for preparing of slaking low at least about 75wt%, preferably at least about 90wt%, more preferably at least about 95wt%, most preferably at least about 99wt%.

The preferred form of the present invention relates to a tobacco articles, comprise the tobacco that the content of the distinctive nitrosamine of at least a tobacco is lowered, method for making comprises makes tobacco stand the microwave radiation under the state that formation of slaking and the distinctive nitrosamine of at least a tobacco is not easy to suppress.

In another embodiment, the present invention relates to a kind of method that the distinctive content of nitrosamines of at least a tobacco in the brown tobacco of slaking is reduced, comprise

With the brown tobacco rehydration of slaking and

Under predetermined energy level, the tobacco of rehydration is carried out the time of the pre-fixed length of microwave radiation.

Similarly, the present invention includes such tobacco articles, comprise the brown tobacco of slaking, the distinctive content of nitrosamines of at least a tobacco is lowered in the tobacco, and its method for making comprises

With the brown tobacco rehydration of slaking and

Under predetermined energy level, the tobacco of rehydration is carried out the time of the pre-fixed length of microwave radiation.

In another embodiment, the present invention relates to a kind of method of producing tobacco product, comprise

Make the tobacco leaf of results stand the microwave radiation, and the not slaking of described tobacco leaf, and the amount that is in the distinctive nitrosamine of tobacco is easy to be lowered or the formation of the distinctive nitrosamine of tobacco is easy to repressed state, radiated time be enough to the amount of the distinctive nitrosamine of at least a tobacco in the tobacco leaf reduced or time that the formation of the distinctive nitrosamine of at least a tobacco in the tobacco leaf is suppressed basically and

Make the tobacco product of the tobacco leaf that comprises that microwave treatment is crossed, this tobacco product is selected from cigarette, cigar, chewing tobacco, snuff and contains chewing gum and the lozenge of tobacco.

Find that also the electromagnetic radiation shorter than microwave range frequency height discussed above, wavelength can be used for realizing basic purpose of the present invention--reduce or eliminate TSNA in the tobacco product substantially, method is to handle tobacco with this form of energy, identical promptly after results described in the embodiment of processing time and top microwave treatment will more specifically be described below.So the invention still further relates to the amount of the nitrosamine in a kind of tobacco leaf that reduces results or prevent the method that nitrosamine forms therein, comprise

Make at least a portion of tobacco leaf stand the radiation higher than microwave frequency, and described part is to be easy to be lowered or the formation of nitrosamine is easy to repressed state without amount slaking and that be in nitrosamine, and radiated time is to be enough to reduce the amount of at least a nitrosamine or to prevent the time that at least a nitrosamine forms basically.

Identical with the microwave treatment embodiment, the step that stands the radiation higher than microwave frequency in preferred the inventive method is that tobacco leaf or its part are carried out, and carry out before a large amount of accumulation on the blade after tobacco leaf begins yellow and at the distinctive nitrosamine of tobacco.Basically carry out this radiation before the lost cell integrality at tobacco leaf in also preferred the inventive method.The energy that can produce this radiation will be further described below, and comprises far infrared and infra-red radiation, UV (ultraviolet ray), soft X-ray or laser, accelerated particle beam such as electron beam, X ray and gamma-rays.

The accompanying drawing summary

Fig. 1 is the photo of explanation Fo Jiniya flue-cured tobacco (flue) tobacco results backs 24-72 hour " yellow ".

Fig. 2 is the photo of explanation the present invention through low-nitrosamine " yellow " Fo Jiniya of microwave treatment flue-cured tobacco tobacco.

Fig. 3 is local lateral perspective, is removable, plant-scale microwave generator (microwave applicator) that can be used for carrying out microwave treatment of the present invention.

Detailed Description Of The Invention

It is said that the slaking of tobacco is that a science is not equal to it is an art, because the slaking condition in any given maturing process all must be regulated according to many factors, as the difference of kind, from the difference of the blade of the diverse location results of stem, between the used curing chamber difference, during season or the environmental change between several different season, the particularly Changes in weather during air-slake.For example, sootiness operates in says so by rule of thumb in a way, is preferably finished by this area working people for many years, a large amount of experiences of accumulation.Referring to, as people such as Peele, " chemistry and the biochemistry of tobacco in the sootiness process changes ", the latest developments of tobacco science, 21 volumes, 81 pages and back page or leaf, Symposium Proceedings 49th Meeting Chemists ' ResearchConference, 24-27 day September nineteen ninety-five, Lexington, Kentucky (below be called " people such as Peele ").Therefore, the those of ordinary skill in tobacco slaking field is understandable that, the external parameter of the wide region of the present invention to a certain degree is being variable, and this depends on the accurate fusion of the above-mentioned factor of arbitrary given results.

In a preferred embodiment, the present invention is based upon in such discovery, promptly have a Best Times (window) in the process of tobacco slaking circulation, can handle tobacco in this Best Times, method therefor makes the formation of TSNA be prevented from basically.Certainly, can eliminate or reduce basically the accurate Best Times that TSNA forms effectively and depend on tobacco type, ageing method and multiple other variable factors, comprise above-mentioned those.According to the preferred embodiments of the invention, this Best Times time corresponding section for the results rear blade be not newly tap or stage of " green " and at TSNA and/or nitrosamine before a large amount of accumulation on the blade; This time period is usually experienced the yellow process with blade or is consistent in the time in yellow stage, before blade begins browning and before the integrality of lost cell basically.Except explanation is arranged in context in addition, terminology used here " basically " and " in a large number " refer generally to give or take leading or main status at relative meaning.In this time period, one section of the microwave radiation that tobacco is exposed to a predetermined power level is predetermined long-time, and the formation of TSNA is easy to be prevented basically in the tobacco leaf, and perhaps, the amount of any TSNA that has formed is easy to be reduced, as described further below.This microwave treatment has suppressed forming naturally of TSNA basically, and a kind of golden yellow dry tobacco leaf of the people's of being suitable for consumption is provided.If TSNA has begun a large amount of accumulation, arrive the end in yellow stage usually, the microwave energy that applies to tobacco leaf according to the present invention has suppressed natural TSNA effectively and has formed circulation, has so just prevented that the further a large amount of of TSNA from forming.If the Best Times in slaking circulation is handled yellow or yellow tobacco by this way, the TSNA amount of gained tobacco product basically with the green tobacco of new harvesting in amount approaching, and kept its local flavor and taste simultaneously.

In another embodiment, the present invention relates to handling through the tobacco of overcuring (browning), to reduce the TSNA content of described tobacco through overcuring effectively, method is to the tobacco rehydration of slaking and makes the slaking tobacco of rehydration stand the microwave radiation, will be further described below.

The present invention is suitable for handling the results tobacco of using for people's consumption.For tobacco, particularly many researchs have been carried out at the distinctive nitrosamine of tobacco.The tobacco leaf of newly gathering is called as " green tobacco ", does not contain known carcinogenic substance, but green tobacco is not suitable for for human consumption.The method of slaking green tobacco depends on the type of the tobacco of gathering in the crops.For example, Fo Jiniya flue-cured tobacco (Fo Jini hypotype bigleaf tobacco) tobacco generally is sootiness, and burley tobaccos and some dark kind generally are air slaked.Carry out comparing in one or two many months with air-slake, the sootiness of tobacco will be carried out five to seven days time usually.According to people such as Peele, sootiness generally is divided into three phases: yellow (35-40 ℃) about 36-72 hour is (although other people report that yellow began in the time that is shorter than 36 hours, as some Fo Jiniya flue-cured tobacco cultivars about 24 hours the time), blade drying (40-57 ℃) 48 hours, He Zhongmai (offal) dry (57-75 ℃) 48 hours.Many main chemistry and biochemistry change the commitment that begins and last till the blade drying in the yellow stage.

In typical fume smoking method, the yellow stage is to carry out in a bin.In this stage, because chlorophyllous degraded, green tobacco leaf loses color gradually, presents the yellow of carotenoid pigment.According to people's such as Peele viewpoint, the yellow stage of sootiness tobacco is by closing the outside gas outlet of bin, and maintains the temperature at about 35-37 ℃ and realize.The method is utilized controlled environment, keeps relative humidity in the bin about 85%, the moisture loss of limit blade, and make blade continue to start from the metabolic process in farmland.The operator will constantly monitor the progress of slaking, mainly is to observe the chlorophyll on the blade and the green situation that loses and the needed lemon development to gold orange look leaf color.

For a kind of concrete Fo Jiniya flue-cured tobacco cultivars of having carried out above-mentioned test, the green tobacco of newly gathering was positioned under about 100-110 °F in the bin about 24-48 hour, until blade yellowing (see figure 1) fully more or less.The amount of moisture that yellow tobacco reduces is the about 90wt% during from green, the about 70-40wt% during to yellow.In this stage, yellow tobacco is substantially devoid of known carcinogenic substance, basic identical in the green tobacco of the content of TSNA and new results.This Fo Jiniya flue-cured tobacco tobacco generally kept yellow about 6-7 of stage days, and after this tobacco leaf becomes brown by yellow.The moisture of brown Fo Jiniya flue-cured tobacco tobacco is generally the about 15wt% of about 11-.Tobacco has caused forming of nitrosamine and a large amount of accumulation by Huang to brown transformation, and content of microorganisms increases simultaneously.The distinctive nitrosamine of tobacco forms really the cutter reason and it be unclear that, but can believe that activation of microorganism can promote it to form, and comprises the effect of the nitrate reductase of microorganism to the formation of nitrite in the maturation process process.

It is believed that the distinctive nitrosamine of tobacco is nitrosation material such as the NO that amine and nitrite are derived ₂, N ₂O ₃And N ₂O ₄Reaction forms under acid condition.The hypothesis that people such as Weirnik have discussed TSNA at the 43-45 page or leaf forms, and its summary provides below.

The amine that contains a large amount of amino acid, protein and alkaloid form in the tobacco leaf.Tertiary amine nicotine (being designated as (1) in figure below) is the main alkaloid in the tobacco, and other nicotinoids alkaloid is less important amine nornicotine (2), anatabine (3) and anabasine (4).Tobacco generally also contains maximum 5% the nitrate and the nitrite of trace.

The nitrosation of nornicotine (2), anatabine (3) and anabasine (4) produces corresponding nitrosamine: N '-nitrosonornicotine (NNN, 5), N '-nitroso anatabine (NAT, 6) and N '-nitroso anabasine (NAB, 7).The nitrosation of nicotine (1) in the aqueous solution produces the mixture of 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone (NNK, 8) (NNN, 5) and 4-(N nitroso methylamino)-4-(3 pyridine radicals)-1-butyraldehyde (NNA, 9).The TSNA that does not often run into comprises NNAL (4-N nitroso methylamino)-1-(3-pyridine radicals)-1-butanols, 10), different-NNAL (4-N-nitroso methylamino)-4-(3-pyridine radicals)-1-butanols, 11) and different-NNAC (4-(N-nitroso methylamino)-4-(3-pyridine radicals)-butyric acid, 12).Generate the route of the TSNA that above-mentioned 1-12 represents such as the diagram of illustrating below (from people's such as Weirnik supra, 44 pages are duplicated) by corresponding nicotiana alkaloids.

What generally all agree now is that the green tobacco of newly gathering does not in fact contain nitrite or TSNA, and these compounds are to produce in slaking of tobacco and storage.The research of being done in past 10 years attempt to determine with the tobacco maturing process in the relevant factor of formation of TSNA, and confirmed several important factors, comprise the genotype of crop, maturity, slaking condition and the activation of microorganism of crop when gathering in the crops.

Studies show that, nitrite and the TSNA accumulation when air-slake occurred in the time interval that finishes when starting from yellow end and the complete browning of blade, for example, be results backs 2-3 weeks for some air slaked kind, the sootiness kind is after the results about about 1 week.This time is that cell leaks into the time that the space between cells loses integrality because of losing moisture and cellular content.Therefore, the Best Times of a weak point is arranged in the air-slake process, this moment, cell decomposed, and nutriment can be utilized by microorganism.People such as Weirnik point out that as the result of alienation nitrate reduction, nitrite can accumulate then in a large number, so just make the formation of TSNA become possibility.

The influence to the tobacco of tobacco leaf and slaking in the growth of tobacco and maturing process of related microorganism group has some open reports, quotes as people such as Weirnik.But relating to the microorganism nitrite reductase in the maturing process in the generation of nitrate supposes.When eucaryotic cell structure was destroyed after the yellow stage, microorganism that nutriment can be invaded utilized, thereby can be to produce nitrite under high humidity, best temperature and the anoxia condition under the suitable condition.Still enough high at water activity, quite short " Best Times " arranged when eucaryotic cell structure has been decomposed usually.

According to the present invention, the formation of TSNA is carried out the microwave radiation under these conditions by the tobacco leaf to results basically and is prevented or suppress in the tobacco.In a preferred embodiment, the time of tobacco leaf between beginning yellow and basic lost cell integrality is exposed to microwave energy.In order to obtain optimum efficiency, the tobacco leaf that preferably makes results is with the form of monolithic tobacco leaf rather than pile up or the form of bundling tobacco leaf is passed through microwave field.It has been determined that handling tobacco leaf has by this way prevented the distinctive nitrosamine of tobacco fully or basically, comprises the formation of known carcinogenic substance NNN and NNK.

According to the preferred embodiments of the invention, can obtain being suitable for content human consumption, the distinctive nitrosamine of at least a tobacco non-green and/or the yellow tobacco product lower than common slaking tobacco.As mentioned above, tobacco green or that newly gather is unsuitable for human consumption usually; " non-green " described here refers to tobacco and loses most of chlorophyll at least, comprises that unrestricted part is turned to be yellow, jaundice reaches the tobacco leaf that begins browning in some position fully.In preferred embodiments, the content of the TSNA of non-green tobacco goods (NNN, NNK, NAB and NAT) is lower than 0.2 μ g/g, more preferably less than about 0.15 μ g/g, even more preferably less than about 0.1 μ g/g, the content of NNN is lower than about 0.15 μ g/g, more preferably less than about 0.10 μ g/g, even more preferably less than about 0.05 μ g/g, the content of NNK is lower than about 0.002 μ g/g, more preferably less than about 0.001 μ g/g, even more preferably less than about 0.0005 μ g/g.As mentioned above, provide the number that can influence the factor that TSNA forms in tobacco, it is not absolute but preferred range that those of ordinary skills understand these numerals.

The invention still further relates to a tobacco articles, it comprises the yellow dried tobacco that is suitable for human consumption, and the content of the distinctive nitrosamine of at least a tobacco is lower than common slaking tobacco.In preferred embodiments, the TSNA of yellow tobacco product (NNN, NNK, NAB and NAT) content, NNN content and NNK content fall into above-mentioned preferred range.

In another embodiment, non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for human consumption, within about 25wt% of TSNA (NNN, NNK, NAB and NAT) the content content that is this TSNA in being used for preparing the green tobacco crop of newly gathering of this goods.More preferably, within about 10wt% of the content that the TSNA content of non-green or yellow tobacco product is this TSNA in being used for preparing the tobacco crop of newly gathering of this goods, more preferably within about 5wt%, most preferably basically near (as in the scope of a few percent by weight).For example, the present invention can prepare such tobacco product, and its TSNA that contains amount falls into above-mentioned scope, and is the manyfold of tobacco of newly gathering with the general TSNA that produces of tobacco of identical crop normal maturation.The present invention can make the amount of nitrosamine be locked on the low content in the green tobacco of newly gathering effectively.Also preferred non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for human consumption, and be selected from NNN, NNK, within about 25wt% of the content of at least a TSNA of NAB and the NAT content that is corresponding TSNA in being used for preparing the green tobacco crop of newly gathering of this goods, preferably within about 10wt%, more preferably within about 5wt%, most preferably basically near (as in the scope of a few percent by weight).In other words, such as, the content of NNN in tobacco of the present invention fall into above-mentioned NNN in the corresponding scope of amount of green tobacco of newly gathering, perhaps the content of NNN+NNK in tobacco of the present invention fall into above-mentioned NNN+NNK in the corresponding scope of amount of green tobacco of newly gathering, or the like.When carrying out these contrasts, preferably after gathering, analyze the content of the green tobacco TSNA that newly gathers within about 24 hours.

In other embodiments of the present invention, non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for human consumption, TSNA (NNN, NNK, NAB and NAT) content than this TSNA with product same type of the present invention, by identical tobacco crop but low for the content that reduces in the tobacco product that slaking prepares under the step that TSNA content designs specially at least about 75wt% at no microwave radiation or other, preferably low at least about 90wt%, more preferably low at least about 95wt% is most preferably low at least about 99wt%.Also preferred non-green or yellow tobacco product comprise non-green or the yellow tobacco that is suitable for people's consumption, it is selected from NNN, NNK, the content of at least a TSNA of NAB and NAT than corresponding TSNA with product same type of the present invention (as, a kind of cigarette and another cigarette than), slaking and content in the tobacco product for preparing hangs down at least about 75wt% with identical tobacco crop but under the technology of no microwave radiation or other reductions TSNA content, preferably at least about 90wt%, more preferably at least about 95wt%, most preferably at least about 99wt%.In these embodiments, the contrast of TSNAwt% can be carried out like this, for example, takes the cigarette that the dried tobacco of yellow of the present invention is made, and take the tobacco crop identical with preparing yellow dried tobacco and in a usual manner slaking do not carry out the cigarette that tobacco that the microwave radiation makes is made, compare.

Wherein preferably tobacco leaf being carried out yellow stage of microwave irradiation step can be broadly define by in following several modes any: (a) check the color of tobacco leaf, when green is made way for yellow basically; (b) measure the percentage that chlorophyll transforms saccharogenesis; (c) observe nitrite begin form or nitrosamine begin produce, this is consistent with the end in yellow stage usually, or (d) measures the moisture of tobacco leaf, as when moisture is the about 70wt% of about 40-.If the microwave radiation imposes on green tobacco, then do not observe the inhibition that nitrosamine is formed or prevent.But when microwave energy after yellow begins, the cell integrality lose before or TSNA when on blade, applying before a large amount of accumulation, the effect that prevents that the reduction of viewed nitrosamine amount or nitrosamine form is significant and unforeseeable, shown in the data of discussing below.

The Best Times that in the yellow phase process tobacco after the results is carried out the microwave radiation changes with multiple factor, comprises the difference of kind, the variation of environment etc.Therefore, (be defined as in the beginning yellow, as, lose a large amount of greens in the blade) to blade basically in the time period between time of lost cell integrality (when its browning look), those of ordinary skills can determine the Best Times that any given tobacco bred is carried out microwave treatment.For example, for a given genotype, can carry out test as herein described to the tobacco leaf sample, measure the content of nitrite or TSNA, TSNA accumulates the relative time of beginning in a large number in given slaking circulation to determine, or determines the transition stage that cell loses integrality.Before a large amount of accumulation of TSNA, tobacco leaf is carried out the most preferably mode that the microwave radiation is the inventive method, but principle of the present invention also goes for the tobacco leaf that is in the forming process, accumulated a large amount of TSNA.When microwave when this carries out than after-stage, the further formation of TSNA can be suppressed effectively.In case but the fully slaking of tobacco leaf warp, the amount of TSNA is just stable basically, applies the content that the microwave radiation can not reduce TSNA again, unless under following rehydration condition.

When standing microwave radiation of the present invention, tobacco leaf generally has low moisture, promptly is lower than about 10wt%, is about 5wt% usually.If desired, blade can rehydration to tobacco browning, after the slaking (as, the Fo Jiniya flue-cured tobacco is about 11-15%) general moisture scope before producing the time such as the tobacco product of cigarette.

The present invention is applicable to the tobacco of all kinds, comprises flue-cured tobacco or the mutation of Fo Jiniya bigleaf tobacco, burley tobaccos mutation, dark fire-cured tobacco mutation, east cigarette mutation/Turkey's cigarette mutation etc.Under the indication of this paper, the best time available that those of ordinary skills can determine in the slaking circulation carries out the microwave step, so that realize objects and advantages of the present invention.

The preferred aspect of the inventive method comprises, to tobacco leaf, preferably includes offal, carry out before the microwave radiation, to the tobacco leaf mechanical expression with from wherein squeezing out the step of redundant moisture, so that guarantee that the drying of carrying out with microwave device is more even.This step can be carried out easily, promptly makes it pass through the suitable rotor roller in a pair of gap before tobacco leaf enters microwave office.This squeezing step helps the moisture in arteries and veins on offal and the less degree and the bigger vein is squeezed out, thereby can obtain better and more uniform dry products.Used roller can be any Len req by hard rubber, plastics or steel preparation, preferably at a distance of about 1/8th to about 1/4th inches, but preferably with this apart from selecting to such an extent that be suitable for accommodating the thickness of the single tobacco leaf that may change.Roller can drive with belt or the chain motor by suitable selection.Except the rotation roller, also can use the extruding of other types or squeezing means to reach identical result if necessary, this is tangible for those of ordinary skills.

Because offal needn't cut away, the preferred embodiment of above-mentioned squeezing tobacco leaf can be finished production more at a high speed, and the time of microwave treatment can shorten.This embodiment is excellent especially to the tobacco leaf that will be used in the cigarette, and this tobacco leaf contains the part of some tobacco offals as admixture usually.Perhaps, offal by the application of pruning and discarding from tobacco leaf, can save the squeezing step if necessary.

In a further preferred embodiment, replace the squeezing tobacco leaf or cut away offal, before microwave treatment, can carry out steam treatment tobacco leaf.The same with the squeezing step, the steam treatment of the whole tobacco leaf that comprises offal has been proved that moisture more is evenly distributed in offal and the bigger vein, thereby made the whole tobacco leaf can be drier when microwave treatment.In tobacco product, can use the whole tobacco leaf that comprises offal when as a result, adopting this special technique.Although details is clearly for a person skilled in the art, with tobacco leaf be placed in the suitable vapor vessel one section be enough to make tobacco leaf slightly deliquescing become the submissive time, when being generally about 30 seconds to about 5 minutes, obtained successful result.

The principle of the invention is also applicable to the brown of rehydration or the tobacco of slaking.In this case, when the brown tobacco of rehydration passes through the microwave radiation, observe TSNA particularly important, the unforeseeable reduction of NNN and NNK content, but the result is so not remarkable when TSNA or nitrite before a large amount of accumulation are used for the present invention the brown tobacco of not slaking in tobacco leaf.But, in the slaking tobacco leaf, add moisture,,, reduced the content of TSNA, shown in the following examples then to rehydration tobacco leaf microwave treatment as tobacco leaf being soaked effectively by spraying enough water.

As mentioned above, when handling the tobacco of slaking or browning, only content of nitrosamines had only very little effect with microwave treatment.But it has been determined that before the microwave radiation slaking tobacco rehydration is helped the effect that microwave energy reduces nitrosamine.In a preferred embodiment, directly in tobacco leaf, add the water of Sq, normally make the tobacco product rehydration of slaking to the water of maximum absorption at least about 10wt%.With the mode identical the rehydration tobacco leaf is exposed to the microwave radiation, content of nitrosamines is reduced, shown in hereinafter with the above-mentioned mode that slaking tobacco is not taked.Tobacco leaf suitable way is arbitrarily got wet.If the tobacco of slaking is the form of non-tobacco leaf, such as the tobacco of " sheet " shape of restoring, can be similarly with the water of for example 10-70wt% with its rehydration, carry out microwave treatment then.Can select suitable microwave condition according to the degree that tobacco leaf is moistening again, but generally fall into the above-mentioned parameter of the yellow tobacco of microwave treatment.

According to the present invention, the brown tobacco of rehydration is carried out microwave treatment can be with TSNA (NNN, NNK, NAB and NAT) content, survey separately or survey altogether, preferably be reduced by at least about 25wt% than the TSNA content in the slaking brown tobacco before the rehydration, more preferably at least about 35wt%, even more preferably at least about 50wt%.

Term used herein " microwave radiation " refers to the electromagnetic energy that frequency and wavelength generally are characterized by the microwave form that falls into the microwave category.Term " microwave " refers generally to the part of electromagnetic spectrum between far-infrared band and conventional radio frequency.The scope of microwave is lower than about 1000MHz from about 1 millimeter of wavelength, the about 300000MHz of frequency slightly to 30 centimetres of wavelength, frequency.The present invention preferably uses high-octane microwave, general lower end in this frequency range.In this preferred frequency range, with microwave with the basic difference of traditional approach such as infrared (for example, in the cooking) heating means be: because penetration power is higher, microwave generally is heated to several centimetres the degree of depth apace, and infrared heating is then much surperficial.In the U.S., industrial microwave apparatus such as micro-wave oven for kitchen use have two kinds of standard frequencies that are respectively about 915MHz and 2450MHz.These frequencies are industrial frequency bands of standard.In Europe, normally used microwave frequency is 2450 and 896MHz.But, can reach objects and advantages of the present invention with the microwave of other frequencies and wavelength through under the condition of appropriate balance.

According to required application, can produce the microwave energy of different capacity level.Microwave generally is to produce with magnetron (magnatron), conventional kitchen level microwave equipment power is 600-1000 watt (being generally about 800 watts), but industrial equipment can produce high extremely hundreds of kilowatts power, generally realizes by adding about 1 kilowatt module (modular source).Magnetron can produce suitable high-frequency pulse or continuous wave.

Radio-frequency generator (applicator) (or stove) is the necessary attaching parts between microwave power generator and the heated material.For purposes of the invention, can use any desirable radio-frequency generator, as long as it is suitable for making tobacco section effectively through raying.Radio-frequency generator should mate so that power transforms bestly with microwave generator, should avoid energy to leak to the outside.For big sample, can use the multimode cavity chamber (micro-wave oven) of diameter if desired greater than several wavelength.In order to ensure the even heating of tobacco leaf, radio-frequency generator can be furnished with oscillation mode agitator (modestirrer) (a kind of head of metal can continuously change field distribution) and movable work-table is looked like conveyer belt.Opposite with the tobacco leaf heap, individual blade thickness is exposed to the microwave radiation can obtains best result.

In the preferred embodiment of the invention, microwave condition comprises, microwave frequency is the about 2500MHz of about 900MHz-, more preferably from about 915MHz and about 2450MHz, to kitchen type radio-frequency generator power is about 600 watts to 300 kilowatts, more preferably from about 600-is about 1000 watts, and industrial multimode radio-frequency generator is about 2-75 kilowatt, and more preferably from about 5-is about 50 kilowatts.Be generally heat time heating time at least about 1 second, be more typically about 10 seconds by about 5 minutes.When handle be individual layer tobacco leaf rather than tobacco leaf heap the time, be preferably about 1 minute to about 21/2 minute following heat time heating time at about 800-1000 watt power.With power bracket higher as 2-75 kilowatt commercial scale radio-frequency generator, when handle be individual layer tobacco leaf rather than tobacco leaf heap the time, can lack heat time heating time, is about 5 seconds to about 60 seconds, is generally 10-30 second under 50 kilowatts of power.Certainly, those of ordinary skills are understood that for any given radio-frequency generator, best microwave field density can be determined according to chamber volume, used power and moisture content in leaves content.Generally speaking, utilize higher power, it is just shorter that tobacco leaf stands the needed time of microwave radiation.

But above-mentioned condition is not absolute, as long as by instruction of the present invention, those of ordinary skill in the art should be able to determine suitable microwave parameters.The microwave radiation preferably is applied to blade or its part, and the processing time is for being enough to effectively drying tobacco, and can charing, so that be suitable for human consumption.Also preferably applying certain hour and power to tobacco leaf or its part is enough to moisture is reduced to and is lower than about 20wt%, the more preferably from about microwave radiation of 10wt%.

With reference now to Fig. 3,, represented the embodiment of a commercial scale microwave generator with fragmentary, perspective view.Specifically, illustrated a Microdry 300kW microwave tobacco drying system 1, comprise movable vehicle frame 2 (the right side front end of figure is not shown), the micro-wave oven 3 of conveyer is set, its inside comprises the furnace chamber (can build with 3003H14 aluminium aptly) of four single wall construction, and recording each chamber is about 16 ' long * 84 " wide * 48 " height.Each chamber is furnished with four access doors, and every side has two.The door be duplex lock so that prevent to be exposed to by accident microwave energy.

In Fig. 3, show an automatic gas cutting machine structure 5, comprise a plurality of (as 12) rotating vane, to remove offal from tobacco leaf 4.Cutting knife can be wide by about 3.4 " straight sheet, to the tobacco leaf center of incision to manual feeding.If desired, can assemble suitable protector, enter so that prevent operator's hand.Although Fig. 3 has illustrated as mentioned above, can use whole tobacco leaf according to a further embodiment of the present invention by the offal cutting machine.Like this, replace the offal cutting mechanism, can use vapor vessel or a pair of roller that from tobacco leaf, squeezes moisture in this equipment.

Get back to Fig. 3, behind the offal cutting operation, the main micro-wave oven 3 of four chambers is arranged in the tobacco leaf of cutting 6 is transported to by conveyer belt 7.In one embodiment, in the system length of stove near 78 feet.When entering in the stove and after entering in the stove, transfer system can alternately form many, 6 polypropylene tapes that speed is variable for example, and it is arranged by this way; Make the offal of cutting-out between two bands, fall into (not shown) the hopper that is contained in the conveyer belt below.Then, conveyer belt carries the tobacco leaf cut by each chamber of being contained in design and being used for holding microwave energy one in two gatherers of one on one side, enters a selected chamber then, and at this, each blade stands microwave treatment by above-mentioned principle of the present invention.After the microwave treatment, conveyer belt carries tobacco leaf through the chamber outlet, discharges micro-wave oven via fire grate material gatherer, and they are admitted to suitable container further to process then.

For the air that will have moisture is removed from chamber and stove, can in system, settle a cover to comprise the gas extraction system (referring to the moisture outlet among Fig. 3, thing 8 is to have done of mark, as representative) of the suitable blower fan that circulating air is provided.If desired, can also control the temperature of furnace interior, thereby in the process of conveyer belt conveying tobacco leaf, the furnace interior branch of outdoor of microwave cavity be remained under the preferred steady temperature, as 160-180 °F by the circulating air convection heat sources that appropriate intervals is opened.Use in the mobile system in field as shown in Figure 3, electric demand can be provided by the diesel-driven generator 9,10 of a pair of routine.Certainly, microwave drying system also can be operated on fixing position, if desired, and by conventional power supply power supply.

Each accepts microwave energy since corresponding M icrodry IV-75 type microwave power supply four chambers among Fig. 3 in the stove 3.Microwave energy enters each chamber through current divider by two holes on each chamber top.In each chamber, be provided with the distribution that the oscillation mode agitator helps microwave energy below the hole.Each microwave power supply is a cell fully independently, in the assembly that needs is arranged with operation 75kW magnetron.The controller of microwave power is positioned on the chamber.This assembly is designed to can unmanned control continued operation under industrial environment.Every microwave power generator can be arranged in each chamber, or with the chamber certain distance is arranged.But the distance 50 ', the loss of waveguide wire are about 2%.Every power generator can provide adjustable microwave energy to industrial operation.Under FCC dividing frequency 915MHz, power output can transfer to about 75kW from 0, and traffic is crossed with the solid-state control loop of control handle manual adjustment on the control panel and controlled or use from the 4-20 milliampere control signal remote control of process controller and control.Though the output of circuit controls power is since 0, the horizontal time-frequency spectrum below about 5kW broadens.The power generator of each chamber is the industrial magnetron of dc source operation basically, and it is by the circuit function element operation and the protection that design for automatic and manually-operated.The circuit function element of generator is by the control panel instrument monitoring that is contained on the cell door.Measure content and comprise anode current, anode voltage, power output, heater current, electromagnetic current and reflection power.The operation of electromechanical interlock element is by the designated lamps monitoring that is contained on the control panel.The door full duration of each microwave power generator room is convenient to admit assembly most possibly.Magnetron and continuous microwave components are housed in the built-in electromagnetic interference shield.Leave door so that settle magnetron and electromagnet.Include in this system and be contained in indoor recycle compressor and water load, under high reflection power condition, play isolator and do in order to the protection magnetron.The microwave power generator comes cooling heating element with compressed air and water.Magnetron and electromagnet are by the demineralized water circulatory system cooling of closed-loop path.Can be with the water in water source independently and the cools down closed circuit.The water source water air heat exchanger in the cell of also flowing through independently is with the air cooling of cell.Centrifugal high pressure fan provides cooling for magnetron output window and cathode construction.The temperature of water and chamber is chain in the control system power transmission chain.The general reference data of each microwave generator in this system is as follows:

Input power 95KVA, 440-480VAC, 3 phases, 60Hz

Power output 915+/-10MHz under 75kW

Magnetron CTL, CWM 75 I

Typical magnetron operation reference data is as follows:

AC filament voltage 11.4V

Heater current 85A

DC anode voltage 17KV

Anode current 5.0A

DC electromagnetism 4.3A

Efficient 80%

In addition, a typical microwave generator can use the carbon steel casing, and suitable position has output to connect (WR 975 waveguides) on the cell top.

In the productivity ratio test, the general microwave Tobacco drying system of design as mentioned above can eliminate the moisture more than 80% in the tobacco leaf effectively.Particularly, in the sample of a mensuration, 15 pounds of supposition original water content are 85wt%, and solid content is that the tobacco leaf of 15wt% is transferred by the microwave chamber with the about 180lb/ of the thickness of monolithic tobacco leaf hour speed.Discharging the back from the microwave chamber weighs to tobacco leaf.Whole weight is 4.6lb, in other words 31% of initial weight.Like this, the original water content based on supposition also remains with 2.35 pounds moisture in tobacco leaf, be equivalent to 18.5% of original water content.

As shown in Figure 2, the microwave treatment of yellow tobacco being carried out according to the present invention preferably obtains golden yellow dried tobacco product.The data here show this dry tobacco, and under its state of not inhaled as yet, carcinogenic nitrosamine, particularly NNN are compared with common slaking tobacco with NNK and significantly reduced.

Also find than above-mentioned microwave range the electromagnetic radiation of concentrating (concentrated) form that frequency is higher, wavelength is shorter (promptly, can be exposed to concentrating of sunlight in the visible spectrum or electric light difference with general) can be used for realizing basic purpose of the present invention--reduce or eliminate TSNA in the tobacco product basically, method is to handle tobacco with this form of energy, and the processing time is approximately with top identical at the described results back time of microwave treatment embodiment.In other words, when using such alternative energy source, can adopt with top at microwave treatment described identical common and optimization technique and principle; For example, the time period roughly the same after results is handled tobacco with this radiation, tobacco leaf can be removed offal before the radiation, squeezes between roller or steams etc.

But, although this alternative energy has been determined year obviously and has reduced ideally or eliminate TSNA basically or prevent that it from forming, without any tested other embodiments the so good effect of the dry tobacco leaf of microwave technology that describes in detail is above arranged up to now.Therefore when using the alternative energy of this class, preferably to further processing through the tobacco leaf of overshoot so that finish the slaking circulation, as in conjunction with irradiation step and follow-up oven drying or roller drying step.

Specifically, believe in any conventional electromagnetic spectrum, than microwave frequency high electromagnetic radiation source and accelerated particle beam, as electron beam all can tobacco as yet not slaking and being in be easy to reduce the TSNA amount or suppress obviously to reduce, eliminate and/or prevent substantially under the state that TSNA forms the formation of TSNA.In the scope of electromagnetic spectrum, microwave is commonly defined as and comprises that frequency is 10 ¹¹Hz, wavelength are 3 * 10 ^-3The electromagnetic radiation of rice, such energy includes but not limited to frequency about 10 ¹²Hz-10 ¹⁴Hz, wavelength are 3 * 10 ^-4-3 * 10 ^-6The far infrared and the infra-red radiation of rice, frequency is about 10 ¹⁶Hz-10 ¹⁸Hz, wavelength are 3 * 10 ^-8-3 * 10 ¹⁰The ultraviolet ray of rice, grenz ray or laser, cathode-ray (from the electronegative electron stream of vacuum tube negative electrode) to surperficial Vertical Launch, X ray and gamma-rays, general features is that frequency is 10 under corresponding wavelength ²¹Hz and Geng Gao.

What it will be apparent to those skilled in the art that is, the dose of radiation that the energy discharges is big more, and tobacco leaf is short more through the time that raying reaches needed effect.Typically, when using the higher radiation source of this frequency, radiated time is lower than 1 minute, preferably is shorter than 30 seconds, even more preferably is shorter than about 10 seconds.Alternatively definition, radiated time was preferred at least about 1 second.But, shown in the following examples, can control exposure speed if necessary and come in time passing release of radiation dosage.For example, the radiation of 1 Megarad can instantaneous relase come out (the same) with the electron-beam accelerator described in the following embodiment 17, perhaps with a predetermined exposure speed (as the sealing chamber γ radiation test discussed in following examples 19 is example, wherein 1 Megarad (10k gray(Gy)) radiation with about 0.8 Megarad/hour exposure speed discharge).When using the high frequency radiation source, the preferred amount of radiation that adopts reduces 50% for making TSNA at least than untreated sample.Though concrete for those of ordinary skills dose of radiation and exposure speed depend on the specific requirement of application and the kind of radiation source, but the general preferred tobacco sample that makes stands about 10 Megarads of about 0.1-, more preferably from about about 5 Megarads of 0.5-, the more preferably from about radiation of about 1.5 Megarads of 0.75-.

Illustrated in the following embodiments, with accelerated electron beam, CO ₂Laser and γ radiation are tested multiple tobacco sample as the example of other radiation source.In each case, tobacco sample slaking, the process irradiation shows that all TSNA content obviously reduces and/or elimination basically.

In another embodiment of the invention, in the circulating air convection furnace, the tobacco that is in easy treatment state is handled, also be proved to be the content that has reduced TSNA, although the quality of tobacco leaf descends to some extent.With common, can not effectively reduce TSNA content and also can reduce the baking box of tobacco quality different, in the circulating air convection furnace, from about 100 °F to about 500 temperature heating, be when the temperature range lower end 1 hour heat time heating time, to in about 5 minutes of when upper end of temperature, can be effectively under tobacco is in the above-mentioned sensitization of this paper definition, reduce TSNA in tobacco content or suppress the formation of TSNA.Even more preferably, the heating furnace that circulating air Convective Heating and microwave radiation combine can shorten the quality of improving tobacco leaf heat time heating time simultaneously.For example, when independent use convection furnace, vein and offal are still fully not dry when blade-section is dry, thereby cause blade-section overdrying and frangible.Microwave treatment and the heating of circulative convection stove obtain more even dry product in conjunction with the quality that can improve blade.

On the other hand, the present invention relates to reduce or eliminate smoking, chewing tobacco basically or otherwise taken in the human body of tobacco or the method for the content of the tobacco-specific nitrosamine in the animal body, the tobacco product that method provides a kind of obvious minimizing or eliminated TSNA basically is for consumption.

Make the tobacco of not slaking stand microwave or other emittance are proved to be able to provide effectively content of nitrosamines to make us low uncannily tobacco.The bottom offal of peelling off and discard tobacco leaf 1/3rd to 1/2nd length can promote these technology, particularly above-mentioned go offal, water squeezing or steams under the situation of step not adopting.Removed offal in this mode, the tobacco leaf of the microwave treatment of gained does not need to use thrashing machine, because the undesirable part of offal has been removed.As a result, the tobacco product loss relevant with knocking can be avoided usually, reduces the nearly 10%-30% of waste of tobacco.

Improvement tobacco of the present invention can replace the tobacco of common slaking whole or in part in any tobacco product, described tobacco product comprises cigarette, cigar, chewing tobacco, tobacco chewing gum, tobacco lozenge, tobacco pouch, snuff or tobacco flavouring agent and food additives.For smoking, the present invention can provide less noxious odor when keeping good suction properties and having the local flavor of common nicotine content fully.For chewing gum, snuff, tobacco pouch and food additives, tobacco of the present invention has pleasant mellow local flavor.

Now in conjunction with the following examples explanations the present invention, but and limit the scope of the invention by any way without these embodiment.

Embodiment 1

Results Fo Jiniya flue-cured tobacco.Tobacco leaf is placed in the curing chamber, under about 100-110 °F, begins sootiness and handle.After the tobacco leaf flavescence, be about results back 24-36 hour, from the chamber, take out sample 1-3.Sample 1 is the blade sample, peels off middle arteries and veins, bakes in the convection current air furnace under about 400-500 ℃ about 1 hour, makes tobacco leaf sheet browning.Sample 2 is yellow blades, places Go1dstarMA-1572M type micro-wave oven (2450MHz), sets about 21/2 minute of high power (1000 watts) heating, rotates during heating.Sample 3 is yellow tobacco leaves, does not handle, with comparing.Sample 4 and 5 is retained in the curing chamber under about 180 high temperature, and sample 4 is dry in the shelf outside, and sample 5 is dry in the shelf the inside.Sample 6 is brown blades of slaking, handles through common sootiness.

Each sample is analyzed, measured NNN, NAT, the content of NAB and NNK.In the embodiment of this and back, " TSNA " represents this four summation that grows tobacco distinctive nitrosamine.After carrying out typical TSNA analysis, sample is put in order and extracted (referring to, for example, people such as the Burton, " distribution of tobacco component in the tobacco tissue.1, the distinctive nitrosamine of tobacco, nitrate, nitrite and alkaloid "; J.Agric.Food Chem.; roll up 40,1992 years the 6th phases), with Thermedics Inc.TEA 543 type thermal energy analyzer and Hewlett-Packard 5890 each TSNA of A type chromatogram ration analysis.The results are shown in following table 1.Below all data in each table with the micrograms of nitrosamine in every gram sample (that is, hundred very much umber or μ g/g) expression.

Table 1

Test piece number (Test pc No.)	????NNN	???NAT+NAB	????NNK	????TSNA
					The yellow flue-cured tobacco of 1-	???0.0310	???0.843	??＜0.0004	??0.1157
The yellow microwave treatment tobacco leaf of 2-	??＜0.0004	?＜0.0006	??＜0.0005	??＜0.0014
					The yellow contrast of 3-	???0.0451	???0.1253	??0.0356	??0.2061
4-is dry at frame extra income rapid-curing cutback	???0.6241	???1.4862	??1.2248	??3.3351
					5-is rapid draing in frame	???0.7465	???1.5993	??1.3568	??3.7044
The common sootiness of 6-	???1.0263	???1.7107	??2.2534	??4.9904

Embodiment 2

Results Fo Jiniya flue-cured tobacco.Sample 7 is to use the green tobacco leaf of newly gathering that compares, and sample 8 is the green tobacco leaves of newly gathering through the microwave radiation, and with MicroDry of Louisville, the multimode microwave generator that Kentucky produces at 2450MHz, was operated about 20 seconds down for 2.5 kilowatts.Sample 9-12 makes of the brown tobacco of common sootiness.Sample 9 is the tobaccos in the cigarette that makes; Sample 10 is the loose pipe tobaccos that are used for making cigarette; Sample 11 is identical with 10 (loose) with sample 9 (cigarette) respectively with 12, and just they all pass through the microwave treatment with sample 8 the same terms.Content with the methods analyst TSNA identical with embodiment 1.The results are shown in table 2.

Table 2

Test piece number (Test pc No.)	????NNN	???NAT+NAB	????NNK	????TSNA
					The new fresh tobacco leaf contrast of 7-	??0＜0.0104	????0.126	????0.0005	????0.126
The new fresh tobacco leaf microwave treatment of 8-	????0.029	????0.135	????0.0004	????0.164
					9-contrasts cigarette	????1.997	????3.495	????2.735	????8.226
The 10-contrast is loose	????2.067	????3.742	????2.982	????8.791
					11-cigarette microwave treatment	????2.056	????3.499	????2.804	????8.359
The loose microwave treatment of 12-	????2.139	????3.612	????2.957	????8.707

Embodiment 3

Below the cigarette brand shown in the table 3 be at Lexington, the different retailers of Kentucky locate stochastic buying, with the content of the methods analyst TSNA described in the embodiment 1.

Table 3

Test piece number (Test pc No.)	Code name	??NNN	?NAT+NAB	???NNK	??TSNA
						?13-Marlboro-king-pc	??288292	??3.565	??4.538	??1.099	??9.202
?14-Marlboro-king-pc	??288292	??4.146	??4.992	??1.142	??10.279
						?15-Marlboro-king-pc	??288292	??3.580	??4.290	??1.106	??8.977
?16-Marlboro-king-pc	??288292	??3.849	??4.748	??1.130	??9.728
						?17-Marlboro-lights-100’s-bx	??288192	??4.604	??5.662	??1.223	??11.489
?18-Marlboro-lights-100’s-pc	??288182	??3.471	??3.859	??1.211	??8.541
						?19-Marlboro-lights-100’s-pc	??288182	??3.488	??4.136	??1.074	??8.698
?20-Marlboro-lights-100’s-pc	??288182	??3.566	??4.240	??1.164	??8.970
						?21-Winston-100’s-pc	??123143	??2.311	??2.968	??1.329	??6.608
?22-Winston-king	??123103	??2.241	??2.850	??1.256	??6.348
						?23-Winston-king-bx	??125123	??2.162	??2.831	??1.326	??6.319
?24-Winston-king-bx	??123123	??2.577	??3.130	??1.207	??6.914
						?25-Winston-king-pc	??123103	??1.988	??2.563	??1.234	??5.786
?26-Winston-lights-100’s-pc	??123133	??2.161	??2.706	??1.258	??6.124
						?27-Winston-lights-100’s-pc	??123133	??2.189	??2.699	??1.262	??6.150
?28-Winston-lights-100’s-pc	??123133	??2.394	??3.385	??2.330	??8.109

Embodiment 4

Results Fo Jiniya flue-cured tobacco.Tobacco leaf is placed on beginning sootiness processing in about 100-110 curing chamber.After the tobacco leaf flavescence, take out them from curing chamber results back about 24-36 hour, sets high power (1000 watts) with Goldstar MA-1572 M type micro-wave oven (2450MHz) and carried out microwave treatment about 21/2 minute, simultaneously rotation.This operation is dry effectively with tobacco leaf, though they do not have browning, has kept their golden yellow.Tobacco leaf is shredded and is made cigarette.Sample 29-33 takes from and is labeled as a collection of of Red Full Flavor, and sample 34-38 takes from and is labeled as a collection of of Blue Light.Sample 39-42 is the cigarette of buying from the health food shop, and plate is Natural American Spirit.TSNA content with the methods analyst sample 29-42 described in the embodiment 1 the results are shown in following table 4.

Table 4

Test piece number (Test pc No.)		?NNN	?NAT+NAB	?NNK	?TSNA
						?29-RED ?FULL ?FLAVOR ?REP?1		?0.138	?0.393	＜0.0005	?0.532
?30-RED ?FULL ?FLAVOR ?REP?2		?0.192	?0.231	＜0.0005	?0.423
						?31-RED ?FULL ?FLAVOR ?REP?3		?0.129	?0.220	＜0.0007	?0.349
?32-RED ?FULL ?FLAVOR ?REP?4		?0.145	?0.260	＜0.0007	?0.406
						?33-RED ?FULL ?FLAVOR ?REP?5		?0.140	?0.293	＜0.0006	?0.434
	????AVG	?0.149	?0.279	＜0.0006	?0.429
							????STD	?0.022	?0.062	0.0001	?0.059
?34-BLUE ?LIGHT ?REP?1		?0.173	?0.162	＜0.0005	?0.335
						?35-BLUE ?LIGHT ?REP?2		?0.046	?0.229	＜0.0005	?0.275
?36-BLUE ?LIGHT ?REP?3		?0.096	?0.188	＜0.0005	?0.285
						?37-BLUE ?LIGHT ?REP?4		?0.067	?0.215	＜0.0005	?0.282
?38-BLUE ?LIGHT ?REP?5		?0.122	?0.218	?＜0.0005	?0.341
							????AVG	?0.101	?0.202	?＜0.0005	?0.304
	????STD	?0.044	?0.024	?0.0000	?0.028
						?39- ?NATURAL ?AMERICAN ?SPIRIT		?0.747	?1.815	?1.455	?4.017

Test piece number (Test pc No.)		???NNN	?NAT+NAB	??NNK	??TSNA
						??40- ??NATURAL ??AMERICAN ??SPIRIT		??0.762	??1.805	??1.458	??4.025
??41- ??NATURAL ??AMERICAN ??SPIRIT		??0.749	??1.826	??1.464	??4.039
						??42- ??NATURAL ??AMERICAN ??SPIRIT		??0.749	??1.760	??1.462	??3.971
	????AVG	??0.752	??1.802	??1.460	??4.013
							????STD	??0.006	??0.025	??0.004	??0.025

STD in this paper table be shown in the standard error of sample mean.

Embodiment 5

Results Fo Jiniya flue-cured tobacco.Tobacco leaf being placed in about 100-110 the curing chamber beginning sootiness handles.Sample 43-44 is after the tobacco leaf flavescence, and take out from curing chamber results back about 24-36 hour, stood the microwave radiation about 20 and 30 seconds with above-mentioned MicroDry multimode microwave generator with about 6 kilowatts power respectively.Sample 43 and 44 is the golden yellow dry tobacco leafs after the microwave treatment.Sample 45-51 makes of the brown slaking tobacco leaf handling through conventional sootiness.Sample 45 is control samples; Sample 46 and 47 is baking about 1 and about 3 minutes in being preheating to about 400-500 convection furnace respectively; Sample 48 and 49 is respectively at Waveguide WR-975 type microwave generator, the large-scale multimode stove (power setting is 0-75KW) that a kind of MicroDry produces, in stand microwave radiation (915MHz), 50 kilowatts about 10 and 40 seconds down.Sample 50 and 51 is pipe tobaccos (recovery sheet) of making of the sootiness tobacco leaf.Sample 50 stands about 1.5 minutes of microwave radiation under 50 kilowatts in the Waveguide micro-wave oven, sample 51 about 3 minutes of baking in being preheating to about 400-500 convection furnace.TSNA content with these samples of methods analyst described in the embodiment 1 the results are shown in following table 5.

Table 5

Test piece number (Test pc No.)	????NNN	??NAT+NAB	????NNK	????TSNA
					43-microwave treatment 20 seconds	??＜0.0106	??＜0.1068	??＜0.0007	??＜0.1181
44-microwave treatment 30 seconds	??＜0.0103	??＜0.1065	??＜0.0004	??＜0.1172
					Microwave treatment is not carried out in the 45-contrast	????0.92	????2.05	????3.71	????6.68
46-convection furnace 1 minute	????1.14	????2.41	????5.10	????8.66
					47-convection furnace 3 minutes	????0.89	????2.06	????2.68	????5.64
10 seconds 50KW of 48-Waveguide	????1.00	????2.31	????3.29	????6.59
					40 seconds 50KW of 49-Waveguide	????0.62	????1.55	????1.69	????3.86
Waveguidel.5 minute 50KW of 50-pipe tobacco	????4.22	????4.91	????0.99	????10.12
					51-pipe tobacco convection furnace 3 minutes	????4.76	????5.60	????1.08	????11.44

Embodiment 6

Results Fo Jiniya tobacco.Tobacco leaf being placed in about 100-110 the curing chamber beginning sootiness handles.Sample 52-55 is the yellow tobacco of taking out from curing chamber by after about 24-36 hour, at Goldstar MA-1572M type micro-wave oven (2450MHz), sets under the high power (1000 watts) through the about cigarette of making in 2 minutes of microwave radiation.In order to contrast, sample 61 and 62 is by handling through conventional sootiness, the cigarette of making without the tobacco leaf of microwave treatment.Sample 56 is slakings; Sample 57 is not fully slakings after the jaundice; Sample 58 is blades of slaking, and then sample 59 and 60 is middle arteries and veins of slaking.Measure TSNA content according to embodiment 1, the results are shown in following table 6.

Table 6

Test piece number (Test pc No.)	????NNN	??NAT+NAB	????NNK	????TSNA
					52-Goldsmoke cigarette	????0.12	????0.23	????0.03	????0.38
53-Goldsmoke?II，85mm	????0.062	????0.326	????0.016	????0.404
					54-Goldsmoke?85mm	????0.128	????0.348	????0.029	????0.504
55-Goldsmoke 100 ' s sample B	????0.166	????0.317	????0.047	????0.531
					56-sample M-M	????3.269	????4.751	????0.833	????8.853
57-sample B-C	????0.267	????0.720	????0.954	????1.941
					58-blade M-C	????0.933	????1.456	????1.968	????4.356
59-WM	????0.996	????1.028	????0.408	????2.432
					60-SM	????1.745	????1.753	????0.306	????3.804
The 61-Goldsmoke contrast	????1.954	????1.544	????0.492	????3.990
					The 62-Goldsmoke contrast	????1.952	????1.889	????0.424	????4.265

Embodiment 7

Results Fo Jiniya flue-cured tobacco.Sample 63 and 66 is the green tobaccos of newly gathering of not slaking, yet stops for 1 week before TSNA measures, and certain air-slake takes place like this.Remaining tobacco leaf is placed in about 100-110 the curing chamber beginning sootiness and handles.Sample 68 is the tobacco leaves that take out from curing chamber after about 24-36 hour flavescence after results, and the power with 25 kilowatts in above-mentioned Waveguide multimode generator carried out the microwave radiation about 40 seconds.

Sample 64/65 (tobacco leaf) and 67/70 (restore the sheet tobacco, or cigarette " silk ") proved that the present invention stands the effect of microwave radiation after slaking tobacco rehydration.Sample 64 and 65 is tobacco leaf samples of handling through conventional sootiness; But sample 64 carries out rehydration second by about 5-10 under the tap of opening.Tobacco leaf has absorbed a large amount of moisture.Then, sample 64 and 65 all carried out microwave treatment about 40 seconds under 25 kilowatts in Waveguide multimode generator.Sample 67 and 70 is the recovery sheet tobacco samples with the preparation of slaking tobacco leaf.Make a large amount of moisture of sample 67 absorptions reach rehydration by adding water, under the condition of said sample 64, carry out the microwave radiation then.Sample 70 does not carry out microwave treatment.Sample 69,71 and 72 is with other slaking tobacco leaves that compare.Content according to embodiment 1 measurement TSNA the results are shown in following table 7.

Table 7

Test piece number (Test pc No.)	????NNN	???NAT+NAB	????NNK	????TSNA
					63-contrasts not slaking	????0.010	????0.263	????0.000	????0.274
64-is through overcuring 40 seconds (wetting)	????0.737	????1.252	????1.?893	????3.882
					65-was through overcuring 40 seconds	????0.767	????1.520	????2.229	????4.516
Not slaking 40 seconds of 66-	????0.010	????0.261	????0.000	????0.272
					The 67-pipe tobacco is through slaking 40 seconds (wetting)	????0.769	????1.328	????0.308	????2.405
68-is 40 seconds 25KW Waveguide of slaking not	????0.051	????0.244	????0.014	????0.308
					69-slaking contrast	????0.866	????1.548	????2.545	????4.960
70-contrasts pipe tobacco	????1.872	????2.536	????0.789	????5.197
					The whole tobacco leaf of 71-contrast " AL "	????0.230	????0.606	????0.746	????1.582
72-SML puts in order tobacco leaf	????0.413	????0.884	????1.514	????2.810

Embodiment 8

Results Fo Jiniya flue-cured tobacco.Tobacco leaf being placed in about 100-110 the curing chamber beginning sootiness handles.Sample 73 is the tobacco leaves that take out from curing chamber after the tobacco leaf flavescence in about 24-36 hour after results, sets about 2 minutes of high power microwave radiation in Goldstar MA-1572M type micro-wave oven.Sample 74-76 sootiness in the usual way.Sample 74 is reference examples of slaking.Sample 75 and 76 is pressed embodiment 7 rehydrations (sample 64), each sample about respectively 20 seconds of microwave radiation (sample 75) and about 40 seconds (sample 76) in MicroDry generator (2450MHz) then, and power is about 6 kilowatts.Sample 77-79 is the sheet tobacco with the recovery of the tobacco leaf preparation of sootiness.Sample 77 is control samples, and sample 78 and 79 is pressed embodiment 7 (sample 67) rehydration.Sample 78 and 79 is about 30 seconds of microwave treatment in the MicroDry generator respectively; Sample 78 is placed on the bottom of stove, and sample 79 is contained in the styrofoam cup and raises several inches, can heat more evenly.Press embodiment 1 and measure TSNA content, the results are shown in the following table 8.

Table 8

Test piece number (Test pc No.)	????NNN	??NAT+NAB	????NNK	????TSNA
					The 73-yellow/through microwave treatment	????0.052	????0.260	??＜0.0004	????0.313
74-A-contrasts tobacco leaf, through slaking	????1.168	????1.904	????1.662	????4.734
					75-B-20 second	????0.791	????1.705	????1.115	????3.611
76-C-40 second	????0.808	????1.624	????1.160	????3.592
					77-contrasts sheet	????4.417	????1?697	????0.960	????9.073
78-30 second	????2.755	????2.553	????0.644	????5.952
					79-30 raises second	????1.606	????1.732	????0.350	????3.687

Embodiment 9

Sample 80-81 is the Redman chewing tobacco of locating to buy the retailer.Sample 80 is contrasts, and sample 81 is set high power microwave radiation about 1-2 minute in Goldstar MA-1572M type micro-wave oven.Sample 82-83 is the Skoal snuff of locating to buy the retailer.Sample 82 is contrasts, and sample 83 is to be same as the mode microwave radiation of sample 81.Measure the content of TSNA, the results are shown in the following table 9.

Table 9

Test piece number (Test pc No.)	????NNN	???NAT+NAB	????NNK	????TSNA
					Before the 80-chewing tobacco microwave	????0.712	????0.927	????0.975	????1.713
Behind the 81-chewing tobacco microwave	????0.856	????0.906	????0.122	????1.884
					Before the 82-snuff microwave	????4.896	????10.545	????1.973	????17.414
Behind the 83-snuff microwave	????6.860	????14.610	????1.901	????23.370

Embodiment 10

After microwave radiation of the present invention, whether can accumulate in time yellow tobacco in order to test TSNA, after for the first time measuring TSNA content 7 wheat harvesting periods to embodiment 4 in the additional cigarette sample of test (label-A)-sample 29,35 and 39 (contrasts) are carried out the TSNA content of embodiment 4 records again and are tested.The results are shown in following table 10.

Table 10

Test piece number (Test pc No.)	??NNN	??NAT	??NAB	??NNK	??TSNA
						?29A-RED?FF?REP?#1	?0.1109	?0.1877	?0.1078	??0.0015	??0.4079
?35A-Blue?Light?#2	?0.0508	?0.1930	?0.1075	??0.0012	??0.3625
						?39A-Natural?American?Spirit?#1	?0.6151	?1.2357	?0.1072	??0.9302	??2.8882

Embodiment 11

Results Fo Jiniya flue-cured tobacco is placed on tobacco leaf beginning sootiness processing in about 100-110 the curing chamber.After the tobacco leaf flavescence, take out tobacco leaf results back about 24-36 hour from curing chamber, sets high power microwave radiation about 2-21/2 minute in Goldstar MA-1572M type micro-wave oven.Each blade is golden yellow, obtains efficient drying.Some samples are indicated " grinding ", and the shape material of claying into power subsequently can be used for for example chewing gum, lozenge or food additives.Tobacco leaf by microwave treatment 6 wheat harvesting periods after, the TSNA content of sample below the method for describing with embodiment 1 is measured.The results are shown in following table 11.

Table 11

Test piece number (Test pc No.)	?????NNN	?????NAT	?????NAB	?????NNK	?????TSNA
						84-grinds	????0.0013	????0.0018	????0.0018	????0.0015	????0.0064
85-grinds	????0.0469	????0.0341	????0.0011	????0.0009	????0.0831
						86-grinds	????0.0009	????0.0582	????0.0013	????0.0011	????0.0615
87-grinds	????0.0113	????0.1078	????0.1078	????0.0015	????0.2284
						88-grinds	????0.0569	????0.1401	????0.1071	????0.0009	????0.3051
89-grinds	????0.0109	????0.1642	????0.1073	????0.0011	????0.2835
						90-grinds	????0.0008	????0.0011	????0.0011	????0.0009	????0.0038
91-grinds	????0.0009	????0.0012	????0.0012	????0.0010	????0.0044
						92-grinds	????0.0012	????0.1059	????0.0017	????0.0014	????0.1101
93-grinds	????0.0013	????0.0529	????0.0019	????0.0015	????0.0576
						94-grinds	????0.0012	????0.0613	????0.0017	????0.0014	????0.0657
95-grinds	????0.0506	????0.0989	????0.0013	????0.0010	????0.1518
						96-grinds	????0.0017	????0.0894	????0.0024	????0.0019	????0.0954
97-grinds	????0.0012	????0.0017	????0.0017	????0.0014	????0.0061
						98-grinds	????0.0016	????0.0023	????0.0023	????0.0019	????0.0082
99-grinds	????0.0342	????0.0016	????0.0016	????0.0013	????0.0386
						100-grinds	????0.0014	????0.0020	????0.0020	????0.0016	????0.0070
The 101-tobacco leaf	????0.0013	????0.0539	??＜0.0019	??＜0.0016	????0.0587
						The 102-tobacco leaf	????0.0009	????0.0012	??＜0.0012	??＜0.0010	????0.0043
103-shreds tobacco leaf	????0.0202	????0.0327	??＜0.0007	??＜0.0006	????0.0542

Embodiment 12

Results Fo Jiniya flue-cured tobacco is placed on tobacco leaf beginning sootiness processing in about 100-110 the curing chamber.Sample 104 and 105 is to have carried out common sootiness to handle the tobacco leaf sample that does not carry out microwave treatment.Sample 104 is middle arteries and veins of slaking, and sample 105 is blades of slaking.Sample 106 is after the tobacco leaf flavescence, the yellow tobacco leaf that took out from curing chamber in about 24-36 hour the results back.After the curing chamber taking-up, tobacco leaf is set high power microwave radiation about 2-21/2 minute in Goldstar MA-1572M type micro-wave oven.Tobacco leaf is golden yellow, obtains efficient drying.Some dry blades are further pressed traditional approach processing to form tobacco extract, and it is designated as sample 107 for analysis.Measure the TSNA content of sample 104-107 with the method for embodiment 1 description.The results are shown in the following table 12.

Table 12

Test piece number (Test pc No.)	????NNN	??NAT?&?NAB	????NNK	????TSNA
					Arteries and veins in the 104-contrast	????0.083	????0.180	??＜0.003	????0.266
105-contrasts blade	????0.928	????1.367	????2.613	????4.908
					106-microwave treatment tobacco leaf	??＜0.004	??＜0.006	??＜0.005	??＜0.015
107-microwave treatment extract	??＜0.004	??＜0.005	??＜0.004	??＜0.013

Embodiment 13

Results Fo Jiniya flue-cured tobacco is placed on tobacco leaf beginning sootiness processing in about 100-110 the curing chamber.Sample 108 and 109 is tobacco leaf samples of handling through conventional sootiness.Sample 108 is blades of slaking, and sample 109 is middle arteries and veins of slaking.Sample 110 and 111 is after the tobacco leaf flavescence, results back about 24-36 hour, the yellow tobacco of taking out from curing chamber.After taking out from curing chamber, sample 110 and 111 heats in Sharp Carousel No.R-9H84B type convection current/micro-wave oven at the circulating air convection furnace.Sample 110 was at about 300 following Fast Heating 5-10 minutes.Sample 111 is heating more lentamente under lower temperature, in about 100 beginnings, rises to about 150 °F after more than 10 minute, and be more than 20 minute heat time heating time altogether.Measure the TSNA content of sample 108-111 with the method for embodiment 1 description.The results are shown in the following table 13.

Table 13

Test piece number (Test pc No.)	????NNN	??NAT?&?NAB	????NNK	????TSNA
					108-contrasts blade	????1.267	????2.509	????1.377	????5.153
Arteries and veins in the 109-contrast	??＜0.004	????0.464	??＜0.004	????0.472
					The 110-convection current is quick	??＜0.004	??＜0.005	??＜0.004	??＜0.013
The 111-convection current at a slow speed	??＜0.003	??＜0.004	??＜0.003	??＜0.010

Although demonstrate the amount of convection furnace heating reduction TSNA, the mass ratio of tobacco is poor by the tobacco that preferred embodiment of the present invention microwave treatment obtains.And heat time heating time must be than with microwave radiation processing or long with the required time of other form high frequency radiations.Particularly Convective Heating can not be fixed on color desirable golden yellow, and blade tends to super-dry and frangible, and vein and middle arteries and veins are then fully not dry.Otherwise, the most preferred embodiment according to the present invention, the tobacco leaf of microwave treatment is by efficient drying and keeping golden yellow after being subject to processing, and the soft pliable song is convenient to further processing simultaneously, in particular as cigarette.In the sample of convection furnace processing, blade is tending towards being broken into powder and little tobacco particle when dry.

Embodiment 14

Results Kentucky burley tobaccos, tobacco leaf following processing after beginning flavescence in about 24-48 after the results hour.Sample 112-117 is this a collection of tobacco leaf sample, further following processing.Sample 112 is microwave treatment under the condition of the sample 106 that is approximately identical to embodiment 12.Tobacco leaf is for golden yellow and obtain efficient drying.Sample 113,114 and 117 heats in being same as embodiment 13 described circulating air convection furnaces, the heating condition of sample 113 and sample 110 roughly the same, the condition of the heating condition of sample 114 and sample 111 is roughly the same, and sample 117 heated about 20 minutes down at about 350 °F.Sample 113,114 and 117 quality and embodiment 13 described samples 110 and 111 similar.Sample 115 and 116 heats in the Sharp Carousel convection current/micro-wave oven described in the embodiment 13, combines with microwave (30%) and convection current (300 ℃), is dried to golden yellow effectively until tobacco leaf.Measure the TSNA content of sample 112-117 with embodiment 1 described method.The results are shown in following table 14.

Table 14

Test piece number (Test pc No.)	????NNN	??NAT?&?NAB	????NNK	????TSNA
					The 112-microwave treatment	??＜0.007	??＜0.010	??＜0.008	??＜0.025
The 113-convection current	??＜0.003	??＜0.004	??＜0.003	??＜0.010
					The 114-convection current	??＜0.012	??＜0.017	??＜0.014	??＜0.043
115-microwave (30%)/convection current	??＜0.002	??＜0.003	??＜0.003	??＜0.008
					116-microwave (30%)/convection current	??＜0.002	??＜0.003	??＜0.002	??＜0.007
The 117-convection current	????0.131	????0.156	???＜0.003	????0.290

Embodiment 15

Results Fo Jiniya flue-cured tobacco is placed on tobacco leaf beginning sootiness processing in about 100-110 the curing chamber.Sample 118-120 takes out from curing chamber after tobacco leaf begins yellow, carries out in common micro-wave oven for kitchen use soon the about 2-21/2 of microwave radiation minute thereafter, becomes golden yellow until the tobacco leaf efficient drying, but does not have the tobacco leaf sample of burning or charing.Sample 121 and 123 is Kentucky burley tobaccos samples, and it is gathered in the crops and processes by every kind of following situation after the beginning yellow.Sample 121 is placed in tobacco industry traditional steam roller drier commonly used, under about 200 °F, up to tobacco leaf browning and dry a little.Sample 122 about 2 minutes of high power microwave radiation in above-mentioned Goldstar micro-wave oven, the water rehydration also is placed on and makes tobacco leaf browning a little in the drum dryer, it is believed that can promote local flavor like this.Sample 123 resembles to be handled the sample 122, just its rehydration not through 1 minute microwave radiation and before putting into drum dryer.Measure the content of TSNA like that by embodiment 1, the results are shown in following table 15.

Table 15

Test piece number (Test pc No.)	????NNN	??NAT?&?NAB	????NNK	????TSNA
					????118	??＜0.003	????0.150	??＜0.003	????0.156
????119	??＜0.003	??＜0.004	??＜0.003	??＜0.010
					????120	??＜0.002	??＜0.003	??＜0.003	??＜0.008
????121	????0.486	????1.059	??＜0.003	????1.548
					????122	??＜0.004	??＜0.005	??＜0.004	??＜0.013
????123	??＜0.003	??＜0.004	??＜0.004	??＜0.011

Embodiment 16

Results North Carolina burley tobaccos, tobacco leaf after results about 2-3 days begin to carry out following processing after the flavescence.Sample 118 is to use micro-wave oven under high power the microwave radiation about 2 minute tobacco leaf sample of the same type with above-mentioned Goldstar micro-wave oven.Tobacco leaf is golden yellow and obtains effective dry after microwave treatment.Measure TSNA content with embodiment 1 described method.The results are shown in the following table 16.

Table 16

Test piece number (Test pc No.)	????NNN	?NAT?&?NAB	????NNK	????TSNA
					????118	????0.024	????0.048	????＜0.001	????0.073

Embodiment 17

This embodiment proves with electron beam irradiation with content that reduces TSNA in the yellow tobacco sample or the validity that prevents its formation basically.Results North Carolina burley tobaccos.Sample 119-122 is the blade sample, be suspended on the outside by common mode and carry out air-slake, up to tobacco leaf by drying and browning effectively.Sample 119 is in contrast not treated.Sample 120 and 121 stands electron beam irradiation on conveyer belt, use Edgewood, the Radiation Dynamics of N.Y., and the Dynamitron electron-beam accelerator that Inc. produces, exposing speed is 1 Megarad.Sample 122 in the Goldstar micro-wave oven about 2 minutes with high power microwave radiation.Sample 123 is samples of getting from its end after burley tobacco leaf begins flavescence.Sample 124 is leaf stalk parts, takes from the crop identical with sample 123, still some green.Sample 125 and 126 is the whole leaf burley tobaccos samples in yellow stage.Use above-mentioned Dynamitron, carry out electron beam irradiation with mode identical and identical exposure speed with said sample 120 and 121.TSNA content according to embodiment 1 described method mensuration said sample the results are shown in the following table 17.

Table 17

Test piece number (Test pc No.)	????NNN	??NAT?&?NAB	????NNK	????TSNA
					119-contrasts slaking	????3.6351	????1.0847	????0.0470	????4.7668
The slaking of 120-high power	????6.5718	????1.7037	????0.4368	????10.7123
					The slaking of 121-low-power	????4.4771	????1.6112	????0.7468	????6.8369
The 122-microwave ripening	????4.8974	????1.6393	????1.1200	????7.6567
					The yellow end of 123-	????0.1812	????0.3667	????0.0013	????0.5492
The green offal of 124-	????0.1918	????0.8310	????0.0016	????1.0243
					125-puts in order leaf	????0.0014	????0.1019	????0.0016	????0.1048
126-puts in order leaf	????0.0646	????0.2465	????0.0019	????0.3130

Although above-mentioned data show electron beam irradiation and can prevent the formation of the distinctive nitrosamine of a large amount of tobaccos in the tobacco leaf sample that is put to the test effectively that tobacco leaf is dried so effectively not as the tobacco leaf that is in similar results back state stands the described microwave radiation of other embodiment of the application.Therefore the processing of commercial Application electron beam irradiation needs other drying steps, as the tobacco leaf after the radiation is carried by conventional drying box to promote maturing process.

Embodiment 18

The high-energy ray that present embodiment proof laser produces also can reach the purpose that the present invention reduces TSNA content effectively.LX-20SP type CO with Luxar Corp. production ₂Laser was carried out radiation to yellow Fo Jiniya flue-cured tobacco in about 2-3 days after results.Use a NovaScan head under superpulse E program, it determines the speed of release, in the radiation diagram number of per second.Set E10, per second discharges 10 times.According to the sub-sample T-1 of 8 tobacco leaves of following scheme radiation to T-8.

Ei0-2 watt	E10-4 watt
		The every side of T-1-is crossed once	The every side of T-5-is crossed once
The every side of T-2-is crossed twice	The every side of T-6-is crossed twice
		The every side of T-3-is crossed three times	The every side of T-7-is crossed three times
The every side of T-4-is crossed four times	The every side of T-8-is crossed four times

2 watt-hours, every run-down or by once discharging the energy of about 120mJ, and 4 watt-hours, the energy of the about 240mJ of same run-down release.

Sub-sample T-1 is to the T-4 mixing and be combined together to form tobacco leaf sample 127, and this sample is pressed the method assessment TSNA content described in the embodiment 1.Sub-sample T-5 mixes similarly and is combined together to form tobacco leaf sample 128 to T-8, and measures the content of its TSNA similarly.The results are shown in following table 18.

Table 18

Test piece number (Test pc No.)	????NNN	?NAT?&?NAB	????NNK	????TSNA
					????127	??0.1031	??0.2025	??0.0006	??0.3061
????128	??0.1019	??0.1287	??0.0010	??0.2315

Identical with embodiment 17 described samples, CO ₂The sample of laser emission can not resemble the sample of microwave radiation dry effectively, although TSNA content is low, therefore will adopt extra drying steps to come the accelerating maturing process.Also has CO ₂After the laser emission before the TSNA test, six a little brownings in eight sub-samples are to the not significantly influence of TSNA content.

Embodiment 19

Present embodiment explanation gamma-rays can prevent effectively that also TSNA from forming in a large number in yellow tobacco.After results about 2-3 days, get the Fo Jiniya flue-cured tobacco after the tobacco leaf flavescence just.Sample 129-132 takes from the blade-section of yellow tobacco leaf respectively, in airtight bin with 8kGrey (0.8 Megarad)/hour exposure speed carry out the γ radiation of 10kGrey (1 Megarad), total about 75 minutes of open-assembly time.By the content of above-mentioned same way as assessment radiation sample TSNA, the results are shown in the following table 19 subsequently.

Table 19

Test piece number (Test pc No.)	????NNN	?NAT?&?NAB	????NNK	????TSNA
					????129	????0.098	????0.225	????0.057	????0.380
????130	??＜0.001	??＜0.001	??＜0.001	??＜0.003
					????131	??＜0.001	??＜0.001	??＜0.001	??＜0.003
????132	????0.033	????0.079	??＜0.001	????0.113

For a person skilled in the art clearly, under the spirit and scope of not leaving claimed invention, can carry out various changes and modifications to embodiment preferred.Therefore, top explanation only should not regarded any restriction as in order to illustrate.

Claims (33)

1. the amount with nitrosamine in the tobacco leaf of results reduces or prevents the method that nitrosamine forms, and comprises

(i) (a) remove offal, (b) excessive moisture removed in tobacco leaf squeezing from tobacco leaf, or (c) make tobacco leaf stand steam treatment step and

(ii) make at least a portion of tobacco leaf stand the microwave radiation, and described part is without slaking and be in and be easy to reduce the amount of nitrosamine or be easy to suppress the state that nitrosamine forms, radiated time is the time that is enough to the amount of at least a nitrosamine is reduced or prevents basically at least a nitrosamine formation, it is wherein said that to stand the microwave radiation be on tobacco leaf or its part, after blade begins yellow and the distinctive nitrosamine of tobacco carries out before a large amount of accumulation in blade and wherein said tobacco leaf or its part is positioned to the thickness of individual layer and do not make tobacco leaf pile up or pile up.

According to the process of claim 1 wherein described step be (b) or (c) and tobacco leaf comprise offal.

3. the amount with nitrosamine in the tobacco leaf of results reduces or prevents the method that nitrosamine forms, and comprises

Make at least a portion of tobacco leaf stand the radiation of concentrating (concentrated) form that the electromagnetic spectrum medium frequency is higher than microwave region, and described part is without slaking and be in and be easy to reduce the amount of nitrosamine or be easy to suppress the state that nitrosamine forms, and radiated time is that the amount with at least a nitrosamine of being enough to reduces or prevents basically the time that at least a nitrosamine forms.

4. according to the method for claim 3, wherein said is on tobacco leaf or its part through raying, carries out before a large amount of accumulation in blade with the distinctive nitrosamine of tobacco after blade begins yellow.

5. according to the method for claim 3, wherein said is to carry out before the basic lost cell integrality of tobacco leaf through raying.

6. according to the method for claim 3, wherein said tobacco leaf is a flue-cured tobacco, describedly carries out within about 24-72 after the results hour through raying.

7. according to the method for claim 3, wherein the time that under predetermined power level tobacco leaf is applied described radiation is at least about 1 second.

8. according to the method for claim 3, wherein saidly prevented the normal accumulation of the distinctive nitrosamine of at least a tobacco in tobacco leaf through raying.

9. method according to Claim 8, the distinctive nitrosamine of wherein said at least a tobacco is selected from N '-nitrosonornicotine, 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone, N '-nitroso anatabine and N '-nitroso anabasine.

10. according to the method for claim 4, wherein said being positioned on the tobacco leaf that the thickness of individual layer do not pile up or pile up through raying carried out.

11. the method according to claim 10 also comprises, before raying, (a) removes offal from tobacco leaf described, (b) excessive moisture is removed in the tobacco leaf squeezing, or (c) is made tobacco leaf stand the step of steam treatment.

12., also be included in and carry out irradiation step afterwards with this part drying according to the method for claim 3.

13. according to the method for claim 3, wherein said radiation is produced by laser beam.

14. according to the method for claim 3, wherein said radiation is the electron beam that is produced by electron accelerator.

15. according to the method for claim 3, wherein said radiation is the γ radiation.

A 16. tobacco articles, the tobacco that the content that comprises the distinctive nitrosamine of at least a tobacco has reduced, its manufacture method is included in tobacco without slaking and when being in the state of the formation that is easy to suppress described at least a tobacco-specific nitrosamine, makes tobacco stand the radiation that the electromagnetic spectrum medium frequency is higher than the concentrated form of microwave region.

17. according to the tobacco product of claim 16, wherein said is on tobacco leaf or its part through raying, carries out before a large amount of accumulation in blade with the distinctive nitrosamine of tobacco after blade begins yellow.

18., wherein saidly carry out before the lost cell integrality basically tobacco through raying according to the tobacco product of claim 16.

19. according to the tobacco product of claim 17, wherein said tobacco is a flue-cured tobacco, describedly carries out within about 72 hours at about 24-after the results through raying.

20. according to the tobacco product of claim 16, wherein said microwave radiation is carried out at least about 1 second tobacco leaf under predetermined power level.

21., wherein saidly prevented the normal accumulation of the distinctive nitrosamine of at least a tobacco in blade through raying according to the tobacco product of claim 20.

22. according to the tobacco product of claim 21, the distinctive nitrosamine of wherein said at least a tobacco is selected from N '-nitrosonornicotine, 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone, N '-nitroso anatabine and N '-nitroso anabasine.

23., wherein saidly the tobacco leaf that is positioned to thickness in monolayer, does not pile up or piles up is carried out through raying according to the tobacco product of claim 17.

24., also be included in describedly before raying according to the tobacco product of claim 23, (a) remove offal from tobacco leaf, (b) excessive moisture is removed in the tobacco leaf squeezing, or (c) made tobacco leaf stand the step of steam treatment.

25., also be included in and carry out irradiation step afterwards with this part drying according to the tobacco product of claim 16.

26. according to the tobacco product of claim 16, wherein said radiation is produced by laser beam.

27. according to the tobacco product of claim 16, wherein said radiation is the electron beam that is produced by electron accelerator.

28. according to the tobacco product of claim 16, wherein said radiation is the γ radiation.

29. the method that the content of the distinctive nitrosamine of at least a tobacco in the brown tobacco of slaking is reduced comprises

With the tobacco rehydration of slaking and

Make the rehydration tobacco under predetermined energy level, stand time of the pre-fixed length of radiation that the electromagnetic spectrum medium frequency is higher than the concentrated form of microwave region.

30. according to the method for claim 29, wherein said rehydration step comprises that adding water in the slaking tobacco makes tobacco absorb the moisture of about 10wt% to the maximum absorbance capacity amount.

31. according to the method for claim 29, the distinctive nitrosamine of wherein said at least a tobacco is selected from N '-nitrosonornicotine, 4-(N-nitroso methylamino)-1-(3-pyridine radicals)-1-butanone, N '-nitroso anatabine and N '-nitroso anabasine.

32. a method of producing tobacco product comprises

Make the tobacco leaf of results stand the radiation that the electromagnetic spectrum medium frequency is higher than the concentrated form of microwave region, and described tobacco leaf is without slaking and be in and be easy to reduce the amount of the distinctive nitrosamine of tobacco or be easy to suppress the state that the distinctive nitrosamine of tobacco forms, radiated time be enough to the amount of the distinctive nitrosamine of at least a tobacco in the tobacco leaf reduced or prevent basically the distinctive nitrosamine of at least a tobacco forms in the tobacco leaf time and

Make the described tobacco product of the tobacco leaf that comprises microwave treatment, this tobacco product is selected from cigarette, cigar, chewing tobacco, snuff and contains chewing gum (gum) and the lozenge of tobacco.

33. according to the method for claim 32, wherein tobacco leaf stands described radiation before a large amount of accumulation with the distinctive nitrosamine of tobacco in tobacco leaf after tobacco leaf begins yellow.

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