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