Sunlight-cured tobacco, Bastam, Iran Curing and subsequent getting old permit for your slow oxidation and degradation of carotenoids in tobacco leaf. This makes specified compounds from the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic taste that contributes into the "smoothness" in the smoke. https://broadfar.com/heated-tobacco-shaping-a-safer-sustainable-smoking-future/