Sunshine-cured tobacco, Bastam, Iran Curing and subsequent getting old permit to the sluggish oxidation and degradation of carotenoids in tobacco leaf. This makes specific compounds within the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" with the smoke. https://broadfar.com/heated-tobacco-shaping-a-safer-sustainable-smoking-future/