Sun-cured tobacco, Bastam, Iran Curing and subsequent growing old enable for the sluggish oxidation and degradation of carotenoids in tobacco leaf. This provides specific compounds inside the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" from the smoke. https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/