Solar-cured tobacco, Bastam, Iran Curing and subsequent getting older allow for your sluggish oxidation and degradation of carotenoids in tobacco leaf. This produces specified compounds within the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic taste that contributes into the "smoothness" in the smoke. https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/