Analysis Of The Volatile Compounds Of Toon A Sinensis And Primary Study Of Its Aro- MA-Producing Mechanism

In this study, volatile compounds of Toona sinensis (TS) tender shoot were analyzed by HS-SPME, GC-MS and GC-O methods. Results indicated that the organic sulfide com-pounds were determinated as to be characteristic constituents of TS. Further more, its aro-ma-producing mechanism was also investigated.The best extraction conditions were obtained by optimization experiments. Under the optimal conditions,56 volatile compounds were separated and 53 were identified by GC-MS. Among them, sulfide compounds and terpenes were the major components. The samples were analyzed by GC-O coupled with GC-MS and two compounds, cis-2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene(9.484%) and trans-2-Mercapto-3,4-dimthyl-2,3-dihydrot-hiophene(16.960%) were ultimately identified as to be characteristic components.The volatiles of garlic, Ailanthus altissima and Toona seeds oil were also studied. Re-sults indicated that there were 26 components could be found both in Ailanthus altissima and TS, of which there were 21 terpenes. There were 7 sulfur compounds could be located both in TS and garlic, which were the reason of pungent flavor of TS. The content of two characteristic compounds of Toona seeds oil was 1.731% and 3.154%, respectively. Less content of characteristic components was why Toona seeds oil presented a milder flavor compared with TS tender buds.The content of volatile compounds, especially characteristic compounds was discerni-bly different betweet several local varieties. The flavor of Ximou red Toona from Shandong province was most concentrated, of which characteristic compounds were the highest (22.210% and 25.650%, respectively). Taihe black oil from Anhui province taste sweet and its terpenes, esters, aldehydes, alcohols content was higher. The content of its characteristic compounds was only 0.093% and 0.155% respectively. The odour of red Toona from Jiaozuo, Henan province was moderate while its characteristic compounds content was 11.180% and 13.530%, respectively.The volatiles of Toona were analyzed during its growing period. The results showed that the content of cis- and trans-2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene, sulfide compounds and terpenes firstly increased and then decreased. It can be assumed that the physiological state, light and temperature may be important factors in the formation of aroma of toona sinensis.The samples were storaged at 25℃ and 0℃ separately and the volatiles of them were analyzed regularly. Under 25℃ condition, the content of characteristic compounds, sulfur compounds and terpenes declined rapidly. Under 0℃ condition, the content of char- acteristic compounds, sulfur compounds firstly increased slowly and then reduced while the content of terpenes was consistent in a downward trend.