Sunlight-cured tobacco, Bastam, Iran Curing and subsequent ageing enable for that gradual oxidation and degradation of carotenoids in tobacco leaf. This generates particular compounds during the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes into the "smoothness" from the smoke. 1600 https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/