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