Study On Flavor Characteristics Of Volatile Organosulfur Compounds In Toona Sinensis

Toona sinensis(TS)is a unique woody vegetable in China with high nutritional and medicinal value.The unique aroma of Toona sinensis is the result of the combined action of sulfur and terpene.In this study,TS var.Jiaozuo,TS var.Linqu,TS var.Heiyouchun,TS var.Bashanhong and TS var.Qingyouchun were used to enrich aroma components through HS-SPME conbined with GC-MS,GC-0 to explore the relationship between characteristic flavor substances and organosulfur compounds of TS.The main results and conclusions were as follows:1.The volatile sulfur content and terpenes of TS of different species showed regular changes at different growth stages,especially for the sulfur content.With the growth period,its relative content increased first and then decreased,and the change was more obvious.The terpene content decreased gradually with the growth of Toona sinensis.2.Sensory evaluation and comparative analysis of volatile components of five species of TS aroma were conducted.The intensity of the aroma of TS var.Jiaozuo,TS var.Heiyouchun,TS var.Linqu,TS var.Bashanhong,TS var.Qingyouchun weakened successively,and their corresponding relative content of sulfur was 65.79%,65.34%,62.98%,52.11%,50.01%,respectively.The sulfur content decreased as the intensity of aroma decreased.Comparing five volatile sulfur compounds of toona sinensis,three flavor substances were found:1,1-thio-propylene,3,4-dimethyl-2-thiophene,1-propyl-1-2-thiolimi-dazole,which presented the cooking flavor,ester aroma and pungent odor respectively.3.The extraction parameters of volatile matter from dried toona sinensis were determined by optimization experiment.Under these conditions,the volatile components of dried Toona sinensis were enriched and analysed.Comparing with fresh TS,the sulfur content of TS in freeze-drying treatment was not significantly difference especially for the content of volatile flavor substances,the dried TS shows a significant decrease in flavoring content.Therefore,the vacuum freeze drying technology could extend the storage period and retain the flavor of TS than common drying technology.