Solar-cured tobacco, Bastam, Iran Curing and subsequent growing old allow with the sluggish oxidation and degradation of carotenoids in tobacco leaf. This provides particular compounds from the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" on the smoke. https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/