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