Effect of vacuum packaging on the formation of TSNAs in tobacco leaves during storage
Experiments were carried out to further clarify the effect of NOx on the formation of TSNAs during tobacco storage. Vacuum treatment was used to change the packing method of tobacco leaves, after which the changes of TSNAs after high temperature treatment and one year of natural storage were studied. Results showed that the TSNA content increased after leaves were treated at 45 °C for 15 days. Compared with the non-vacuum treatment, the increment of four individual and total TSNAs in Burley/flue-cured tobacco leaves and midrib after vacuum packaging were significantly decreased. The TSNA content of Burley tobacco midrib decreased the most, reaching 6.79 µg/g, and the TSNA content of flue-cured tobacco leaves and midrib decreased by 36.2 % and 58.7 %, respectively. After one year natural storage of Burley tobacco with different packing methods, it was found that the increment of TSNAs in the vacuum treated tobacco was least, only increasing by 31 % compared with pre-storage, whereas the TSNA content in samples packaged with plastic bag and newspaper increased by 142.8 % and 140.2 %, respectively. Meanwhile, due to the samples being effectively isolated from the air, the neutral aroma components were significantly higher than samples in other treatments (P<0.05), reaching 632.9 µg/g. Therefore, controlling the storage environment and scavenging NOx could be crucial to reduce or inhibit TSNA formation during leaf storage.