Sun-cured tobacco, Bastam, Iran Curing and subsequent getting older make it possible for for that slow oxidation and degradation of carotenoids in tobacco leaf. This generates sure compounds during the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/