Sun-cured tobacco, Bastam, Iran Curing and subsequent growing older permit for that gradual oxidation and degradation of carotenoids in tobacco leaf. This produces selected compounds within the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes on the "smoothness" of the smoke. https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/