Sunshine-cured tobacco, Bastam, Iran Curing and subsequent growing old let with the gradual oxidation and degradation of carotenoids in tobacco leaf. This makes particular compounds in the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes to the "smoothness" on the smoke. https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/