Effects of UV Radiation on the Internal Quality of Tobacco Top Leaves in Qujing of Yunnan

To investigate the effect of UV radiation on internal quality of tobacco top leaves, Cured B2F leaves from Qujing, Yunnan were collected and three processing samples (sheet tobacco, tobacco and tobacco feeding) were irradiated in close chamber by ultraviolet for different period. Then soluble sugar, alkali, chloride and potassium content of each sample were measured and then sheet tobacco was chose for GC/GC-TOFMS analysis and sensory evaluation. The results showed that treatment of UV/O₃ and UV irradiation for 2.5 hours to sheet tobacco, soluble sugar and alkali contents changed greatly, and chloride content decreased slightly. Fragrance substance analysis by GC/GC-TOFMS showed that the treatment cause the 39 kinds of fragrance substance contents increased by 20%, and generated 18 new fragrance substance. Sensory evaluation showed that UV irradiation significantly improved aroma and strength decreased significantly.