Methods of reducing tobacco-specific nitrosamines (TSNAs) and/or improving leaf quality in tobacco
Methods of curing tobacco that reduce the levels of TSNAs and/or improve leaf quality are described herein.
1. A method of fire curing harvested tobacco comprising:
housing harvested tobacco in a curing barn; and
reducing the relative humidity in the barn to 80% or less within 12 hours of the housing step.
2. The method of claim 1 , wherein the relative humidity in the barn is reduced to 75% or less within 12 hours of the housing step.
3. The method of claim 1 , wherein the relative humidity in the barn is reduced to 70% or less within 12 hours of the housing step.
4. The method of claim 1 , wherein the method reduces the level of at least one TSNA in the cured tobacco.
5. The method of claim 4 , wherein the at least one TSNA is selected from the group consisting of N′-nitrosonornicotine (NNN), 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT) and N′-nitrosoanabasine (NAB).
6. The method of claim 1 , wherein the tobacco is dark fire-cured.
7. The method of claim 1 , wherein the tobacco is partially yellowed at the housing step.
8. The method of claim 1 , wherein the tobacco is pale-yellow tobacco.
9. The method of claim 1 , wherein the tobacco comprises a pale-yellow gene.
10. A method of fire curing harvested tobacco comprising:
housing tobacco in a curing barn; and
drying tobacco under conditions that reduce the level of at least one tobacco-specific nitrosamine (TSNA), wherein the conditions comprise increasing the temperature and decreasing the percent relative humidity to less than 80% within 12 hours of the housing step.
11. The method of claim 10 , wherein the at least one TSNA is selected from the group consisting of N′-nitrosonornicotine (NNN), 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT) and N′-nitrosoanabasine (NAB).
12. The method of claim 10 , wherein the tobacco is dark fire-cured.
13. The method of claim 10 , wherein the tobacco is partially yellowed at the housing step.
14. The method of claim 10 , wherein the tobacco is pale-yellow tobacco.
15. The method of claim 10 , wherein the tobacco comprises a pale-yellow gene.
16. A method of fire curing harvested tobacco comprising:
housing harvested tobacco in a curing barn;
starting fires in the curing barn within 48 hours of the housing step; and
reducing the relative water activity in the tobacco to 0.9 or less within one to three weeks of the housing step.
17. The method of claim 16 , wherein the relative water activity in the tobacco is reduced to 0.85 or less within one to three weeks of the housing step.
18. The method of claim 16 , wherein the relative water activity in the tobacco is reduced to 0.80 or less within one to three weeks of the housing step.
19. The method of claim 16 , wherein the method reduces the level of at least one TSNA in the cured tobacco.
20. The method of claim 19 , wherein the at least one TSNA is selected from the group consisting of N′-nitrosonornicotine (NNN), 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT) and N′-nitrosoanabasine (NAB).
21. The method of claim 16 , wherein the tobacco is dark tobacco.
22. The method of claim 16 , wherein the tobacco is partially yellowed at the housing step.
23. The method of claim 16 , wherein the tobacco is pale-yellow tobacco.
24. The method of claim 16 , wherein the tobacco comprises a pale-yellow gene.