Sunshine-cured tobacco, Bastam, Iran Curing and subsequent aging allow for to the gradual oxidation and degradation of carotenoids in tobacco leaf. This makes particular compounds during the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" with the smoke. https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/