INTERACTING EFFECTS OF TEMPERATURE, MOISTURE CONTENT AND STORAGE ENVIRONMENT ON TOBACCO-SPECIFIC NITROSAMINES FORMATION DURING BURLEY TOBACCO STORAGE

Tobacco-specific nitrosamines (TSNAs) are carcinogenic chemicals found in cured tobacco leaves, which could greatly increase during storage. Interaction of temperature and moisture content and storage environment on TSNAs formation and their precursors change were investigated. Storage temperature and moisture content, along with their interaction, had significant effects on TSNAs formation in tobacco leaves. Storage temperature was the primary source of total variation in TSNAs, with a 56.1% contribution rate. Regression model analysis revealed that TSNAs formation was more sensitive to temperature and its interaction with moisture content and that 25.5 C was the turning point for TSNAs formation. Approximately 96.1% of TSNAs variations were explained by the interaction of changes in storage temperature and moisture content. TSNAs contents of tobacco stored in Zhengzhou (where there is a higher mean temperature and lower humidity) were markedly higher than that of the samples stored in Midu. And the reduction in nicotine, nornicotine, NO3-N, and NO2-N content in the Zhengzhou samples was greater than that in Midu. These results indicated that temperature and moisture content have interactive effects on TSNAs formation during burley tobacco storage. The proper control of storage conditions is an effective way to reduce TSNAs formation in stored tobacco leaves.