Sunlight-cured tobacco, Bastam, Iran Curing and subsequent getting old let to the gradual oxidation and degradation of carotenoids in tobacco leaf. This generates specified compounds within the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic taste that contributes on the "smoothness" in the smoke. https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/